Charles Darwin........................................................................................................................................1

The Origin of Species, by means of Natural Selection; or, The Preservation of Favoured Races in the

Struggle for Life. Popular Edition, with a Photogravure Portrait. Large Crown 8vo. 2s. 6d. net.

A Naturalist's Voyage. Journal of Researches into the Natural History and Geology of the Countries visited

during the Voyage of H.M.S. "Beagle" round the World, under the Command of Capt. Fitz Roy, R.N. Popular

During the successive reprints of the first edition of this work, published in 1871, I was able to introduce

several important corrections; and now that more time has elapsed, I have endeavoured to profit by the fiery

ordeal through which the book has passed, and have taken advantage of all the criticisms which seem to me

sound. I am also greatly indebted to a large number of correspondents for the communication of a surprising

number of new facts and remarks. These have been so numerous, that I have been able to use only the more

important ones; and of these, as well as of the more important corrections, I will append a list. Some new

illustrations have been introduced, and four of the old drawings have been replaced by better ones, done from

life by Mr. T.W. Wood. I must especially call attention to some observations which I owe to the kindness of

Prof. Huxley (given as a supplement at the end of Part I.), on the nature of the differences between the brains

of man and the higher apes. I have been particularly glad to give these observations, because during the last

few years several memoirs on the subject have appeared on the Continent, and their importance has been, in

I may take this opportunity of remarking that my critics frequently assume that I attribute all changes of

corporeal structure and mental power exclusively to the natural selection of such variations as are often called

spontaneous; whereas, even in the first edition of the 'Origin of Species,' I distinctly stated that great weight

must be attributed to the inherited effects of use and disuse, with respect both to the body and mind. I also

attributed some amount of modification to the direct and prolonged action of changed conditions of life.

Some allowance, too, must be made for occasional reversions of structure; nor must we forget what I have

called "correlated" growth, meaning, thereby, that various parts of the organisation are in some unknown

manner so connected, that when one part varies, so do others; and if variations in the one are accumulated by

selection, other parts will be modified. Again, it has been said by several critics, that when I found that many

details of structure in man could not be explained through natural selection, I invented sexual selection; I

gave, however, a tolerably clear sketch of this principle in the first edition of the 'Origin of Species,' and I

there stated that it was applicable to man. This subject of sexual selection has been treated at full length in the

present work, simply because an opportunity was here first afforded me. I have been struck with the likeness

of many of the halffavourable criticisms on sexual selection, with those which appeared at first on natural

selection; such as, that it would explain some few details, but certainly was not applicable to the extent to

which I have employed it. My conviction of the power of sexual selection remains unshaken; but it is

probable, or almost certain, that several of my conclusions will hereafter be found erroneous; this can hardly

fail to be the case in the first treatment of a subject. When naturalists have become familiar with the idea of

sexual selection, it will, as I believe, be much more largely accepted; and it has already been fully and

The nature of the following work will be best understood by a brief account of how it came to be written.

During many years I collected notes on the origin or descent of man, without any intention of publishing on

the subject, but rather with the determination not to publish, as I thought that I should thus only add to the

prejudices against my views. It seemed to me sufficient to indicate, in the first edition of my 'Origin of

Species,' that by this work "light would be thrown on the origin of man and his history;" and this implies that

man must be included with other organic beings in any general conclusion respecting his manner of

appearance on this earth. Now the case wears a wholly different aspect. When a naturalist like Carl Vogt

ventures to say in his address as President of the National Institution of Geneva (1869), "personne, en Europe

au moins, n'ose plus soutenir la creation independante et de toutes pieces, des especes," it is manifest that at

least a large number of naturalists must admit that species are the modified descendants of other species; and

this especially holds good with the younger and rising naturalists. The greater number accept the agency of

natural selection; though some urge, whether with justice the future must decide, that I have greatly overrated

its importance. Of the older and honoured chiefs in natural science, many unfortunately are still opposed to

In consequence of the views now adopted by most naturalists, and which will ultimately, as in every other

case, be followed by others who are not scientific, I have been led to put together my notes, so as to see how

far the general conclusions arrived at in my former works were applicable to man. This seemed all the more

desirable, as I had never deliberately applied these views to a species taken singly. When we confine our

attention to any one form, we are deprived of the weighty arguments derived from the nature of the affinities

which connect together whole groups of organismstheir geographical distribution in past and present

times, and their geological succession. The homological structure, embryological development, and

rudimentary organs of a species remain to be considered, whether it be man or any other animal, to which our

attention may be directed; but these great classes of facts afford, as it appears to me, ample and conclusive

evidence in favour of the principle of gradual evolution. The strong support derived from the other arguments

The sole object of this work is to consider, firstly, whether man, like every other species, is descended from

some preexisting form; secondly, the manner of his development; and thirdly, the value of the differences

between the socalled races of man. As I shall confine myself to these points, it will not be necessary to

describe in detail the differences between the several racesan enormous subject which has been fully

described in many valuable works. The high antiquity of man has recently been demonstrated by the labours

of a host of eminent men, beginning with M. Boucher de Perthes; and this is the indispensable basis for

understanding his origin. I shall, therefore, take this conclusion for granted, and may refer my readers to the

admirable treatises of Sir Charles Lyell, Sir John Lubbock, and others. Nor shall I have occasion to do more

than to allude to the amount of difference between man and the anthropomorphous apes; for Prof. Huxley, in

the opinion of most competent judges, has conclusively shewn that in every visible character man differs less

from the higher apes, than these do from the lower members of the same order of Primates.

This work contains hardly any original facts in regard to man; but as the conclusions at which I arrived, after

drawing up a rough draft, appeared to me interesting, I thought that they might interest others. It has often

and confidently been asserted, that man's origin can never be known: but ignorance more frequently begets

confidence than does knowledge: it is those who know little, and not those who know much, who so

positively assert that this or that problem will never be solved by science. The conclusion that man is the

codescendant with other species of some ancient, lower, and extinct form, is not in any degree new.

Lamarck long ago came to this conclusion, which has lately been maintained by several eminent naturalists

and philosophers; for instance, by Wallace, Huxley, Lyell, Vogt, Lubbock, Buchner, Rolle, etc. (1. As the

works of the first named authors are so well known, I need not give the titles; but as those of the latter are

less well known in England, I will give them:'Sechs Vorlesungen uber die Darwin'sche Theorie:' zweite

Auflage, 1868, von Dr L. Buchner; translated into French under the title 'Conferences sur la Theorie

Darwinienne,' 1869. 'Der Mensch im Lichte der Darwin'sche Lehre,' 1865, von Dr. F. Rolle. I will not attempt

to give references to all the authors who have taken the same side of the question. Thus G. Canestrini has

published ('Annuario della Soc. d. Nat.,' Modena, 1867, page 81) a very curious paper on rudimentary

characters, as bearing on the origin of man. Another work has (1869) been published by Dr. Francesco

Barrago, bearing in Italian the title of "Man, made in the image of God, was also made in the image of the

ape."), and especially by Haeckel. This last naturalist, besides his great work, 'Generelle Morphologie'

(1866), has recently (1868, with a second edition in 1870), published his 'Naturliche Schopfungsgeschichte,'

in which he fully discusses the genealogy of man. If this work had appeared before my essay had been

written, I should probably never have completed it. Almost all the conclusions at which I have arrived I find

confirmed by this naturalist, whose knowledge on many points is much fuller than mine. Wherever I have

added any fact or view from Prof. Haeckel's writings, I give his authority in the text; other statements I leave

as they originally stood in my manuscript, occasionally giving in the footnotes references to his works, as a

During many years it has seemed to me highly probable that sexual selection has played an important part in

differentiating the races of man; but in my 'Origin of Species' (first edition, page 199) I contented myself by

merely alluding to this belief. When I came to apply this view to man, I found it indispensable to treat the

whole subject in full detail. (2. Prof. Haeckel was the only author who, at the time when this work first

appeared, had discussed the subject of sexual selection, and had seen its full importance, since the publication

of the 'Origin'; and this he did in a very able manner in his various works.) Consequently the second part of

the present work, treating of sexual selection, has extended to an inordinate length, compared with the first

I had intended adding to the present volumes an essay on the expression of the various emotions by man and

the lower animals. My attention was called to this subject many years ago by Sir Charles Bell's admirable

work. This illustrious anatomist maintains that man is endowed with certain muscles solely for the sake of

expressing his emotions. As this view is obviously opposed to the belief that man is descended from some

other and lower form, it was necessary for me to consider it. I likewise wished to ascertain how far the

emotions are expressed in the same manner by the different races of man. But owing to the length of the

present work, I have thought it better to reserve my essay for separate publication.

Nature of the evidence bearing on the origin of manHomologous structures in man and the lower

animalsMiscellaneous points of correspondence DevelopmentRudimentary structures, muscles,

senseorgans, hair, bones, reproductive organs, etc.The bearing of these three great classes of facts on the

He who wishes to decide whether man is the modified descendant of some pre existing form, would

probably first enquire whether man varies, however slightly, in bodily structure and in mental faculties; and if

so, whether the variations are transmitted to his offspring in accordance with the laws which prevail with the

lower animals. Again, are the variations the result, as far as our ignorance permits us to judge, of the same

general causes, and are they governed by the same general laws, as in the case of other organisms; for

instance, by correlation, the inherited effects of use and disuse, etc.? Is man subject to similar

malconformations, the result of arrested development, of reduplication of parts, etc., and does he display in

any of his anomalies reversion to some former and ancient type of structure? It might also naturally be

enquired whether man, like so many other animals, has given rise to varieties and subraces, differing but

slightly from each other, or to races differing so much that they must be classed as doubtful species? How are

such races distributed over the world; and how, when crossed, do they react on each other in the first and

The enquirer would next come to the important point, whether man tends to increase at so rapid a rate, as to

lead to occasional severe struggles for existence; and consequently to beneficial variations, whether in body

or mind, being preserved, and injurious ones eliminated. Do the races or species of men, whichever term may

be applied, encroach on and replace one another, so that some finally become extinct? We shall see that all

these questions, as indeed is obvious in respect to most of them, must be answered in the affirmative, in the

same manner as with the lower animals. But the several considerations just referred to may be conveniently

deferred for a time: and we will first see how far the bodily structure of man shews traces, more or less plain,

of his descent from some lower form. In succeeding chapters the mental powers of man, in comparison with

It is notorious that man is constructed on the same general type or model as other mammals. All the bones in

his skeleton can be compared with corresponding bones in a monkey, bat, or seal. So it is with his muscles,

nerves, bloodvessels and internal viscera. The brain, the most important of all the organs, follows the same

law, as shewn by Huxley and other anatomists. Bischoff (1. 'Grosshirnwindungen des Menschen,' 1868, s. 96.

The conclusions of this author, as well as those of Gratiolet and Aeby, concerning the brain, will be discussed

by Prof. Huxley in the Appendix alluded to in the Preface to this edition.), who is a hostile witness, admits

that every chief fissure and fold in the brain of man has its analogy in that of the orang; but he adds that at no

period of development do their brains perfectly agree; nor could perfect agreement be expected, for otherwise

their mental powers would have been the same. Vulpian (2. 'Lec. sur la Phys.' 1866, page 890, as quoted by

M. Dally, 'L'Ordre des Primates et le Transformisme,' 1868, page 29.), remarks: "Les differences reelles qui

existent entre l'encephale de l'homme et celui des singes superieurs, sont bien minimes. Il ne faut pas se faire

d'illusions a cet egard. L'homme est bien plus pres des singes anthropomorphes par les caracteres

anatomiques de son cerveau que ceuxci ne le sont non seulement des autres mammiferes, mais meme de

certains quadrumanes, des guenons et des macaques." But it would be superfluous here to give further details

on the correspondence between man and the higher mammals in the structure of the brain and all other parts

It may, however, be worth while to specify a few points, not directly or obviously connected with structure,

Man is liable to receive from the lower animals, and to communicate to them, certain diseases, as

hydrophobia, variola, the glanders, syphilis, cholera, herpes, etc. (3. Dr. W. Lauder Lindsay has treated this

subject at some length in the 'Journal of Mental Science,' July 1871; and in the 'Edinburgh Veterinary

Review,' July 1858.); and this fact proves the close similarity (4. A Reviewer has criticised ('British Quarterly

Review,' Oct. 1st, 1871, page 472) what I have here said with much severity and contempt; but as I do not use

the term identity, I cannot see that I am greatly in error. There appears to me a strong analogy between the

same infection or contagion producing the same result, or one closely similar, in two distinct animals, and the

testing of two distinct fluids by the same chemical reagent.) of their tissues and blood, both in minute

structure and composition, far more plainly than does their comparison under the best microscope, or by the

aid of the best chemical analysis. Monkeys are liable to many of the same noncontagious diseases as we are;

thus Rengger (5. 'Naturgeschichte der Saugethiere von Paraguay,' 1830, s. 50.), who carefully observed for a

long time the Cebus Azarae in its native land, found it liable to catarrh, with the usual symptoms, and which,

when often recurrent, led to consumption. These monkeys suffered also from apoplexy, inflammation of the

bowels, and cataract in the eye. The younger ones when shedding their milkteeth often died from fever.

Medicines produced the same effect on them as on us. Many kinds of monkeys have a strong taste for tea,

coffee, and spiritous liquors: they will also, as I have myself seen, smoke tobacco with pleasure. (6. The same

tastes are common to some animals much lower in the scale. Mr. A. Nichols informs me that he kept in

Queensland, in Australia, three individuals of the Phaseolarctus cinereus; and that, without having been

taught in any way, they acquired a strong taste for rum, and for smoking tobacco.) Brehm asserts that the

natives of northeastern Africa catch the wild baboons by exposing vessels with strong beer, by which they

are made drunk. He has seen some of these animals, which he kept in confinement, in this state; and he gives

a laughable account of their behaviour and strange grimaces. On the following morning they were very cross

and dismal; they held their aching heads with both hands, and wore a most pitiable expression: when beer or

wine was offered them, they turned away with disgust, but relished the juice of lemons. (7. Brehm,

'Thierleben,' B. i. 1864, s. 75, 86. On the Ateles, s. 105. For other analogous statements, see s. 25, 107.) An

American monkey, an Ateles, after getting drunk on brandy, would never touch it again, and thus was wiser

than many men. These trifling facts prove how similar the nerves of taste must be in monkeys and man, and

Man is infested with internal parasites, sometimes causing fatal effects; and is plagued by external parasites,

all of which belong to the same genera or families as those infesting other mammals, and in the case of

scabies to the same species. (8. Dr. W. Lauder Lindsay, 'Edinburgh Vet. Review,' July 1858, page 13.) Man is

subject, like other mammals, birds, and even insects (9. With respect to insects see Dr. Laycock, "On a

General Law of Vital Periodicity," 'British Association,' 1842. Dr. Macculloch, 'Silliman's North American

Journal of Science,' vol. XVII. page 305, has seen a dog suffering from tertian ague. Hereafter I shall return

to this subject.), to that mysterious law, which causes certain normal processes, such as gestation, as well as

the maturation and duration of various diseases, to follow lunar periods. His wounds are repaired by the same

process of healing; and the stumps left after the amputation of his limbs, especially during an early embryonic

period, occasionally possess some power of regeneration, as in the lowest animals. (10. I have given the

evidence on this head in my 'Variation of Animals and Plants under Domestication,' vol. ii. page 15, and more

The whole process of that most important function, the reproduction of the species, is strikingly the same in

all mammals, from the first act of courtship by the male (11. Mares e diversis generibus Quadrumanorum sine

dubio dignoscunt feminas humanas a maribus. Primum, credo, odoratu, postea aspectu. Mr. Youatt, qui diu in

Hortis Zoologicis (Bestiariis) medicus animalium erat, vir in rebus observandis cautus et sagax, hoc mihi

certissime probavit, et curatores ejusdem loci et alii e ministris confirmaverunt. Sir Andrew Smith et Brehm

notabant idem in Cynocephalo. Illustrissimus Cuvier etiam narrat multa de hac re, qua ut opinor, nihil turpius

potest indicari inter omnia hominibus et Quadrumanis communia. Narrat enim Cynocephalum quendam in

furorem incidere aspectu feminarum aliquarem, sed nequaquam accendi tanto furore ab omnibus. Semper

eligebat juniores, et dignoscebat in turba, et advocabat voce gestuque.), to the birth and nurturing of the

young. Monkeys are born in almost as helpless a condition as our own infants; and in certain genera the

young differ fully as much in appearance from the adults, as do our children from their fullgrown parents.

(12. This remark is made with respect to Cynocephalus and the anthropomorphous apes by Geoffroy

SaintHilaire and F. Cuvier, 'Histoire Nat. des Mammiferes,' tom. i. 1824.) It has been urged by some writers,

as an important distinction, that with man the young arrive at maturity at a much later age than with any other

animal: but if we look to the races of mankind which inhabit tropical countries the difference is not great, for

the orang is believed not to be adult till the age of from ten to fifteen years. (13. Huxley, 'Man's Place in

Nature,' 1863, p. 34.) Man differs from woman in size, bodily strength, hairiness, etc., as well as in mind, in

the same manner as do the two sexes of many mammals. So that the correspondence in general structure, in

the minute structure of the tissues, in chemical composition and in constitution, between man and the higher

[Fig. 1. Shows a human embryo, from Ecker, and a dog embryo, from Bischoff. Labelled in each are:

a. Forebrain, cerebral hemispheres, etc. b. Midbrain, corpora quadrigemina. c. Hindbrain, cerebellum,

medulla oblongata. d. Eye. e. Ear. f. First visceral arch. g. Second visceral arch. H. Vertebral columns and

muscles in process of development. i. Anterior extremities. K. Posterior extremities. L. Tail or os coccyx.]

Man is developed from an ovule, about the 125th of an inch in diameter, which differs in no respect from the

ovules of other animals. The embryo itself at a very early period can hardly be distinguished from that of

other members of the vertebrate kingdom. At this period the arteries run in archlike branches, as if to carry

the blood to branchiae which are not present in the higher Vertebrata, though the slits on the sides of the neck

still remain (see f, g, fig. 1), marking their former position. At a somewhat later period, when the extremities

are developed, "the feet of lizards and mammals," as the illustrious Von Baer remarks, "the wings and feet of

birds, no less than the hands and feet of man, all arise from the same fundamental form." It is, says Prof.

Huxley (14. 'Man's Place in Nature,' 1863, p. 67.), "quite in the later stages of development that the young

human being presents marked differences from the young ape, while the latter departs as much from the dog

in its developments, as the man does. Startling as this last assertion may appear to be, it is demonstrably

As some of my readers may never have seen a drawing of an embryo, I have given one of man and another of

a dog, at about the same early stage of development, carefully copied from two works of undoubted accuracy.

(15. The human embryo (upper fig.) is from Ecker, 'Icones Phys.,' 18511859, tab. xxx. fig. 2. This embryo

was ten lines in length, so that the drawing is much magnified. The embryo of the dog is from Bischoff,

'Entwicklungsgeschichte des HundeEies,' 1845, tab. xi. fig. 42B. This drawing is five times magnified, the

embryo being twentyfive days old. The internal viscera have been omitted, and the uterine appendages in

both drawings removed. I was directed to these figures by Prof. Huxley, from whose work, 'Man's Place in

Nature,' the idea of giving them was taken. Haeckel has also given analogous drawings in his

After the foregoing statements made by such high authorities, it would be superfluous on my part to give a

number of borrowed details, shewing that the embryo of man closely resembles that of other mammals. It

may, however, be added, that the human embryo likewise resembles certain low forms when adult in various

points of structure. For instance, the heart at first exists as a simple pulsating vessel; the excreta are voided

through a cloacal passage; and the os coccyx projects like a true tail, "extending considerably beyond the

rudimentary legs." (16. Prof. Wyman in 'Proceedings of the American Academy of Sciences,' vol. iv. 1860, p.

17.) In the embryos of all airbreathing vertebrates, certain glands, called the corpora Wolffiana, correspond

with, and act like the kidneys of mature fishes. (17. Owen, 'Anatomy of Vertebrates,' vol. i. p. 533.) Even at a

later embryonic period, some striking resemblances between man and the lower animals may be observed.

Bischoff says that "the convolutions of the brain in a human foetus at the end of the seventh month reach

about the same stage of development as in a baboon when adult." (18. 'Die Grosshirnwindungen des

Menschen,' 1868, s. 95.) The great toe, as Professor Owen remarks (19. 'Anatomy of Vertebrates,' vol. ii. p.

553.), "which forms the fulcrum when standing or walking, is perhaps the most characteristic peculiarity in

the human structure;" but in an embryo, about an inch in length, Prof. Wyman (20. 'Proc. Soc. Nat. Hist.'

Boston, 1863, vol. ix. p. 185.) found "that the great toe was shorter than the others; and, instead of being

parallel to them, projected at an angle from the side of the foot, thus corresponding with the permanent

condition of this part in the quadrumana." I will conclude with a quotation from Huxley (21. 'Man's Place in

Nature,' p. 65.) who after asking, does man originate in a different way from a dog, bird, frog or fish? says,

"the reply is not doubtful for a moment; without question, the mode of origin, and the early stages of the

development of man, are identical with those of the animals immediately below him in the scale: without a

doubt in these respects, he is far nearer to apes than the apes are to the dog."

This subject, though not intrinsically more important than the two last, will for several reasons be treated here

more fully. (22. I had written a rough copy of this chapter before reading a valuable paper, "Caratteri

rudimentali in ordine all' origine dell' uomo" ('Annuario della Soc. d. Naturalisti,' Modena, 1867, p. 81), by

G. Canestrini, to which paper I am considerably indebted. Haeckel has given admirable discussions on this

whole subject, under the title of Dysteleology, in his 'Generelle Morphologie' and 'Schopfungsgeschichte.')

Not one of the higher animals can be named which does not bear some part in a rudimentary condition; and

man forms no exception to the rule. Rudimentary organs must be distinguished from those that are nascent;

though in some cases the distinction is not easy. The former are either absolutely useless, such as the

mammae of male quadrupeds, or the incisor teeth of ruminants which never cut through the gums; or they are

of such slight service to their present possessors, that we can hardly suppose that they were developed under

the conditions which now exist. Organs in this latter state are not strictly rudimentary, but they are tending in

this direction. Nascent organs, on the other hand, though not fully developed, are of high service to their

possessors, and are capable of further development. Rudimentary organs are eminently variable; and this is

partly intelligible, as they are useless, or nearly useless, and consequently are no longer subjected to natural

selection. They often become wholly suppressed. When this occurs, they are nevertheless liable to occasional

The chief agents in causing organs to become rudimentary seem to have been disuse at that period of life

when the organ is chiefly used (and this is generally during maturity), and also inheritance at a corresponding

period of life. The term "disuse" does not relate merely to the lessened action of muscles, but includes a

diminished flow of blood to a part or organ, from being subjected to fewer alternations of pressure, or from

becoming in any way less habitually active. Rudiments, however, may occur in one sex of those parts which

are normally present in the other sex; and such rudiments, as we shall hereafter see, have often originated in a

way distinct from those here referred to. In some cases, organs have been reduced by means of natural

selection, from having become injurious to the species under changed habits of life. The process of reduction

is probably often aided through the two principles of compensation and economy of growth; but the later

stages of reduction, after disuse has done all that can fairly be attributed to it, and when the saving to be

effected by the economy of growth would be very small (23. Some good criticisms on this subject have been

given by Messrs. Murie and Mivart, in 'Transact. Zoological Society,' 1869, vol. vii. p. 92.), are difficult to

understand. The final and complete suppression of a part, already useless and much reduced in size, in which

case neither compensation nor economy can come into play, is perhaps intelligible by the aid of the

hypothesis of pangenesis. But as the whole subject of rudimentary organs has been discussed and illustrated

in my former works (24. 'Variation of Animals and Plants under Domestication,' vol. ii pp. 317 and 397. See

also 'Origin of Species,' 5th Edition p. 535.), I need here say no more on this head.

Rudiments of various muscles have been observed in many parts of the human body (25. For instance, M.

Richard ('Annales des Sciences Nat.,' 3rd series, Zoolog. 1852, tom. xviii. p. 13) describes and figures

rudiments of what he calls the "muscle pedieux de la main," which he says is sometimes "infiniment petit."

Another muscle, called "le tibial posterieur," is generally quite absent in the hand, but appears from time to

time in a more or less rudimentary condition.); and not a few muscles, which are regularly present in some of

the lower animals can occasionally be detected in man in a greatly reduced condition. Every one must have

noticed the power which many animals, especially horses, possess of moving or twitching their skin; and this

is effected by the panniculus carnosus. Remnants of this muscle in an efficient state are found in various parts

of our bodies; for instance, the muscle on the forehead, by which the eyebrows are raised. The platysma

myoides, which is well developed on the neck, belongs to this system. Prof. Turner, of Edinburgh, has

occasionally detected, as he informs me, muscular fasciculi in five different situations, namely in the axillae,

near the scapulae, etc., all of which must be referred to the system of the panniculus. He has also shewn (26.

Prof. W. Turner, 'Proceedings of the Royal Society of Edinburgh,' 186667, p. 65.) that the musculus

sternalis or sternalis brutorum, which is not an extension of the rectus abdominalis, but is closely allied to the

panniculus, occurred in the proportion of about three per cent. in upwards of 600 bodies: he adds, that this

muscle affords "an excellent illustration of the statement that occasional and rudimentary structures are

Some few persons have the power of contracting the superficial muscles on their scalps; and these muscles

are in a variable and partially rudimentary condition. M. A. de Candolle has communicated to me a curious

instance of the longcontinued persistence or inheritance of this power, as well as of its unusual

development. He knows a family, in which one member, the present head of the family, could, when a youth,

pitch several heavy books from his head by the movement of the scalp alone; and he won wagers by

performing this feat. His father, uncle, grandfather, and his three children possess the same power to the same

unusual degree. This family became divided eight generations ago into two branches; so that the head of the

abovementioned branch is cousin in the seventh degree to the head of the other branch. This distant cousin

resides in another part of France; and on being asked whether he possessed the same faculty, immediately

exhibited his power. This case offers a good illustration how persistent may be the transmission of an

absolutely useless faculty, probably derived from our remote semihuman progenitors; since many monkeys

have, and frequently use the power, of largely moving their scalps up and down. (27. See my 'Expression of

The extrinsic muscles which serve to move the external ear, and the intrinsic muscles which move the

different parts, are in a rudimentary condition in man, and they all belong to the system of the panniculus;

they are also variable in development, or at least in function. I have seen one man who could draw the whole

ear forwards; other men can draw it upwards; another who could draw it backwards (28. Canestrini quotes

Hyrtl. ('Annuario della Soc. dei Naturalisti,' Modena, 1867, p. 97) to the same effect.); and from what one of

these persons told me, it is probable that most of us, by often touching our ears, and thus directing our

attention towards them, could recover some power of movement by repeated trials. The power of erecting and

directing the shell of the ears to the various points of the compass, is no doubt of the highest service to many

animals, as they thus perceive the direction of danger; but I have never heard, on sufficient evidence, of a

man who possessed this power, the one which might be of use to him. The whole external shell may be

considered a rudiment, together with the various folds and prominences (helix and antihelix, tragus and

antitragus, etc.) which in the lower animals strengthen and support the ear when erect, without adding much

to its weight. Some authors, however, suppose that the cartilage of the shell serves to transmit vibrations to

the acoustic nerve; but Mr. Toynbee (29. 'The Diseases of the Ear,' by J. Toynbee, F.R.S., 1860, p. 12. A

distinguished physiologist, Prof. Preyer, informs me that he had lately been experimenting on the function of

the shell of the ear, and has come to nearly the same conclusion as that given here.), after collecting all the

known evidence on this head, concludes that the external shell is of no distinct use. The ears of the

chimpanzee and orang are curiously like those of man, and the proper muscles are likewise but very slightly

developed. (30. Prof. A. Macalister, 'Annals and Magazine of Natural History,' vol. vii. 1871, p. 342.) I am

also assured by the keepers in the Zoological Gardens that these animals never move or erect their ears; so

that they are in an equally rudimentary condition with those of man, as far as function is concerned. Why

these animals, as well as the progenitors of man, should have lost the power of erecting their ears, we cannot

say. It may be, though I am not satisfied with this view, that owing to their arboreal habits and great strength

they were but little exposed to danger, and so during a lengthened period moved their ears but little, and thus

gradually lost the power of moving them. This would be a parallel case with that of those large and heavy

birds, which, from ihabiting oceanic islands, have not been exposed to the attacks of beasts of prey, and have

consequently lost the power of using their wings for flight. The inability to move the ears in man and several

apes is, however, partly compensated by the freedom with which they can move the head in a horizontal

plane, so as to catch sounds from all directions. It has been asserted that the ear of man alone possesses a

lobule; but "a rudiment of it is found in the gorilla" (31. Mr. St. George Mivart, 'Elementary Anatomy,' 1873,

p. 396.); and, as I hear from Prof. Preyer, it is not rarely absent in the negro.

[Fig. 2. Human Ear, modelled and drawn by Mr. Woolner. The projecting point is labelled a.]

The celebrated sculptor, Mr. Woolner, informs me of one little peculiarity in the external ear, which he has

often observed both in men and women, and of which he perceived the full significance. His attention was

first called to the subject whilst at work on his figure of Puck, to which he had given pointed ears. He was

thus led to examine the ears of various monkeys, and subsequently more carefully those of man. The

peculiarity consists in a little blunt point, projecting from the inwardly folded margin, or helix. When present,

it is developed at birth, and, according to Prof. Ludwig Meyer, more frequently in man than in woman. Mr.

Woolner made an exact model of one such case, and sent me the accompanying drawing. (Fig. 2). These

points not only project inwards towards the centre of the ear, but often a little outwards from its plane, so as

to be visible when the head is viewed from directly in front or behind. They are variable in size, and

somewhat in position, standing either a little higher or lower; and they sometimes occur on one ear and not on

the other. They are not confined to mankind, for I observed a case in one of the spidermonkeys (Ateles

beelzebuth) in our Zoological Gardens; and Mr. E. Ray Lankester informs me of another case in a

chimpanzee in the gardens at Hamburg. The helix obviously consists of the extreme margin of the ear folded

inwards; and this folding appears to be in some manner connected with the whole external ear being

permanently pressed backwards. In many monkeys, which do not stand high in the order, as baboons and

some species of macacus (32. See also some remarks, and the drawings of the ears of the Lemuroidea, in

Messrs. Murie and Mivart's excellent paper in 'Transactions of the Zoological Society,' vol. vii. 1869, pp. 6

and 90.), the upper portion of the ear is slightly pointed, and the margin is not at all folded inwards; but if the

margin were to be thus folded, a slight point would necessarily project inwards towards the centre, and

probably a little outwards from the plane of the ear; and this I believe to be their origin in many cases. On the

other hand, Prof. L. Meyer, in an able paper recently published (33. 'Uber das Darwin'sche Spitzohr,' Archiv

fur Path. Anat. und Phys., 1871, p. 485.), maintains that the whole case is one of mere variability; and that the

projections are not real ones, but are due to the internal cartilage on each side of the points not having been

fully developed. I am quite ready to admit that this is the correct explanation in many instances, as in those

figured by Prof. Meyer, in which there are several minute points, or the whole margin is sinuous. I have

myself seen, through the kindness of Dr. L. Down, the ear of a microcephalous idiot, on which there is a

projection on the outside of the helix, and not on the inward folded edge, so that this point can have no

relation to a former apex of the ear. Nevertheless in some cases, my original view, that the points are vestiges

of the tips of formerly erect and pointed ears, still seems to me probable. I think so from the frequency of

their occurrence, and from the general correspondence in position with that of the tip of a pointed ear. In one

case, of which a photograph has been sent me, the projection is so large, that supposing, in accordance with

Prof. Meyer's view, the ear to be made perfect by the equal development of the cartilage throughout the

whole extent of the margin, it would have covered fully onethird of the whole ear. Two cases have been

communicated to me, one in North America, and the other in England, in which the upper margin is not at all

folded inwards, but is pointed, so that it closely resembles the pointed ear of an ordinary quadruped in

outline. In one of these cases, which was that of a young child, the father compared the ear with the drawing

which I have given (34. 'The Expression of the Emotions,' p. 136.) of the ear of a monkey, the Cynopithecus

niger, and says that their outlines are closely similar. If, in these two cases, the margin had been folded

inwards in the normal manner, an inward projection must have been formed. I may add that in two other

cases the outline still remains somewhat pointed, although the margin of the upper part of the ear is normally

folded inwardsin one of them, however, very narrowly. [Fig.3. Foetus of an Orang(?). Exact copy of a

photograph, shewing the form of the ear at this early age.] The following woodcut (No. 3) is an accurate copy

of a photograph of the foetus of an orang (kindly sent me by Dr. Nitsche), in which it may be seen how

different the pointed outline of the ear is at this period from its adult condition, when it bears a close general

resemblance to that of man. It is evident that the folding over of the tip of such an ear, unless it changed

greatly during its further development, would give rise to a point projecting inwards. On the whole, it still

seems to me probable that the points in question are in some cases, both in man and apes, vestiges of a former

The nictitating membrane, or third eyelid, with its accessory muscles and other structures, is especially well

developed in birds, and is of much functional importance to them, as it can be rapidly drawn across the whole

eyeball. It is found in some reptiles and amphibians, and in certain fishes, as in sharks. It is fairly well

developed in the two lower divisions of the mammalian series, namely, in the monotremata and marsupials,

and in some few of the higher mammals, as in the walrus. But in man, the quadrumana, and most other

mammals, it exists, as is admitted by all anatomists, as a mere rudiment, called the semilunar fold. (35.

Muller's 'Elements of Physiology,' Eng. translat. 1842, vol. ii. p. 1117. Owen, 'Anatomy of Vertebrates,' vol.

iii. p. 260; ibid. on the Walrus, 'Proceedings of the Zoological Society,' November 8, 1854. See also R. Knox,

'Great Artists and Anatomists,' p. 106. This rudiment apparently is somewhat larger in Negroes and

Australians than in Europeans, see Carl Vogt, 'Lectures on Man,' Eng. translat. p. 129.)

The sense of smell is of the highest importance to the greater number of mammalsto some, as the

ruminants, in warning them of danger; to others, as the Carnivora, in finding their prey; to others, again, as

the wild boar, for both purposes combined. But the sense of smell is of extremely slight service, if any, even

to the dark coloured races of men, in whom it is much more highly developed than in the white and civilised

races. (36. The account given by Humboldt of the power of smell possessed by the natives of South America

is well known, and has been confirmed by others. M. Houzeau ('Etudes sur les Facultes Mentales,' etc., tom. i.

1872, p. 91) asserts that he repeatedly made experiments, and proved that Negroes and Indians could

recognise persons in the dark by their odour. Dr. W. Ogle has made some curious observations on the

connection between the power of smell and the colouring matter of the mucous membrane of the olfactory

region as well as of the skin of the body. I have, therefore, spoken in the text of the darkcoloured races

having a finer sense of smell than the white races. See his paper, 'MedicoChirurgical Transactions,' London,

vol. liii. 1870, p. 276.) Nevertheless it does not warn them of danger, nor guide them to their food; nor does it

prevent the Esquimaux from sleeping in the most fetid atmosphere, nor many savages from eating halfputrid

meat. In Europeans the power differs greatly in different individuals, as I am assured by an eminent naturalist

who possesses this sense highly developed, and who has attended to the subject. Those who believe in the

principle of gradual evolution, will not readily admit that the sense of smell in its present state was originally

acquired by man, as he now exists. He inherits the power in an enfeebled and so far rudimentary condition,

from some early progenitor, to whom it was highly serviceable, and by whom it was continually used. In

those animals which have this sense highly developed, such as dogs and horses, the recollection of persons

and of places is strongly associated with their odour; and we can thus perhaps understand how it is, as Dr.

Maudsley has truly remarked (37. 'The Physiology and Pathology of Mind,' 2nd ed. 1868, p. 134.), that the

sense of smell in man "is singularly effective in recalling vividly the ideas and images of forgotten scenes and

Man differs conspicuously from all the other primates in being almost naked. But a few short straggling hairs

are found over the greater part of the body in the man, and fine down on that of the woman. The different

races differ much in hairiness; and in the individuals of the same race the hairs are highly variable, not only in

abundance, but likewise in position: thus in some Europeans the shoulders are quite naked, whilst in others

they bear thick tufts of hair. (38. Eschricht, Uber die Richtung der Haare am menschlichen Korper, Muller's

'Archiv fur Anat. und Phys.' 1837, s. 47. I shall often have to refer to this very curious paper.) There can be

little doubt that the hairs thus scattered over the body are the rudiments of the uniform hairy coat of the lower

animals. This view is rendered all the more probable, as it is known that fine, short, and palecoloured hairs

on the limbs and other parts of the body, occasionally become developed into "thickset, long, and rather

coarse dark hairs," when abnormally nourished near oldstanding inflamed surfaces. (39. Paget, 'Lectures on

I am informed by Sir James Paget that often several members of a family have a few hairs in their eyebrows

much longer than the others; so that even this slight peculiarity seems to be inherited. These hairs, too, seem

to have their representatives; for in the chimpanzee, and in certain species of Macacus, there are scattered

hairs of considerable length rising from the naked skin above the eyes, and corresponding to our eyebrows;

similar long hairs project from the hairy covering of the superciliary ridges in some baboons.

The fine woollike hair, or socalled lanugo, with which the human foetus during the sixth month is thickly

covered, offers a more curious case. It is first developed, during the fifth month, on the eyebrows and face,

and especially round the mouth, where it is much longer than that on the head. A moustache of this kind was

observed by Eschricht (40. Eschricht, ibid. s. 40, 47.) on a female foetus; but this is not so surprising a

circumstance as it may at first appear, for the two sexes generally resemble each other in all external

characters during an early period of growth. The direction and arrangement of the hairs on all parts of the

foetal body are the same as in the adult, but are subject to much variability. The whole surface, including

even the forehead and ears, is thus thickly clothed; but it is a significant fact that the palms of the hands and

the soles of the feet are quite naked, like the inferior surfaces of all four extremities in most of the lower

animals. As this can hardly be an accidental coincidence, the woolly covering of the foetus probably

represents the first permanent coat of hair in those mammals which are born hairy. Three or four cases have

been recorded of persons born with their whole bodies and faces thickly covered with fine long hairs; and this

strange condition is strongly inherited, and is correlated with an abnormal condition of the teeth. (41. See my

'Variation of Animals and Plants under Domestication,' vol. ii. p. 327. Prof. Alex. Brandt has recently sent me

an additional case of a father and son, born in Russia, with these peculiarities. I have received drawings of

both from Paris.) Prof. Alex. Brandt informs me that he has compared the hair from the face of a man thus

characterised, aged thirtyfive, with the lanugo of a foetus, and finds it quite similar in texture; therefore, as

he remarks, the case may be attributed to an arrest of development in the hair, together with its continued

growth. Many delicate children, as I have been assured by a surgeon to a hospital for children, have their

backs covered by rather long silky hairs; and such cases probably come under the same head.

It appears as if the posterior molar or wisdomteeth were tending to become rudimentary in the more

civilised races of man. These teeth are rather smaller than the other molars, as is likewise the case with the

corresponding teeth in the chimpanzee and orang; and they have only two separate fangs. They do not cut

through the gums till about the seventeenth year, and I have been assured that they are much more liable to

decay, and are earlier lost than the other teeth; but this is denied by some eminent dentists. They are also

much more liable to vary, both in structure and in the period of their development, than the other teeth. (42.

Dr. Webb, 'Teeth in Man and the Anthropoid Apes,' as quoted by Dr. C. Carter Blake in Anthropological

Review, July 1867, p. 299.) In the Melanian races, on the other hand, the wisdomteeth are usually furnished

with three separate fangs, and are generally sound; they also differ from the other molars in size, less than in

the Caucasian races. (43. Owen, 'Anatomy of Vertebrates,' vol. iii. pp. 320, 321, and 325.) Prof.

Schaaffhausen accounts for this difference between the races by "the posterior dental portion of the jaw being

always shortened" in those that are civilised (44. 'On the Primitive Form of the Skull,' Eng. translat., in

'Anthropological Review,' Oct. 1868, p. 426), and this shortening may, I presume, be attributed to civilised

men habitually feeding on soft, cooked food, and thus using their jaws less. I am informed by Mr. Brace that

it is becoming quite a common practice in the United States to remove some of the molar teeth of children, as

the jaw does not grow large enough for the perfect development of the normal number. (45. Prof. Montegazza

writes to me from Florence, that he has lately been studying the last molar teeth in the different races of man,

and has come to the same conclusion as that given in my text, viz., that in the higher or civilised races they

With respect to the alimentary canal, I have met with an account of only a single rudiment, namely the

vermiform appendage of the caecum. The caecum is a branch or diverticulum of the intestine, ending in a

culdesac, and is extremely long in many of the lower vegetablefeeding mammals. In the marsupial koala

it is actually more than thrice as long as the whole body. (46. Owen, 'Anatomy of Vertebrates,' vol. iii. pp.

416, 434, 441.) It is sometimes produced into a long graduallytapering point, and is sometimes constricted

in parts. It appears as if, in consequence of changed diet or habits, the caecum had become much shortened in

various animals, the vermiform appendage being left as a rudiment of the shortened part. That this appendage

is a rudiment, we may infer from its small size, and from the evidence which Prof. Canestrini (47. 'Annuario

della Soc. d. Nat.' Modena, 1867, p. 94.) has collected of its variability in man. It is occasionally quite absent,

or again is largely developed. The passage is sometimes completely closed for half or twothirds of its

length, with the terminal part consisting of a flattened solid expansion. In the orang this appendage is long

and convoluted: in man it arises from the end of the short caecum, and is commonly from four to five inches

in length, being only about the third of an inch in diameter. Not only is it useless, but it is sometimes the

cause of death, of which fact I have lately heard two instances: this is due to small hard bodies, such as seeds,

entering the passage, and causing inflammation. (48. M. C. Martins ("De l'Unite Organique," in 'Revue des

Deux Mondes,' June 15, 1862, p. 16) and Haeckel ('Generelle Morphologie,' B. ii. s. 278), have both

In some of the lower Quadrumana, in the Lemuridae and Carnivora, as well as in many marsupials, there is a

passage near the lower end of the humerus, called the supracondyloid foramen, through which the great

nerve of the fore limb and often the great artery pass. Now in the humerus of man, there is generally a trace

of this passage, which is sometimes fairly well developed, being formed by a depending hooklike process of

bone, completed by a band of ligament. Dr. Struthers (49. With respect to inheritance, see Dr. Struthers in the

'Lancet,' Feb. 15, 1873, and another important paper, ibid. Jan. 24, 1863, p. 83. Dr. Knox, as I am informed,

was the first anatomist who drew attention to this peculiar structure in man; see his 'Great Artists and

Anatomists,' p. 63. See also an important memoir on this process by Dr. Gruber, in the 'Bulletin de l'Acad.

Imp. de St. Petersbourg,' tom. xii. 1867, p. 448.), who has closely attended to the subject, has now shewn that

this peculiarity is sometimes inherited, as it has occurred in a father, and in no less than four out of his seven

children. When present, the great nerve invariably passes through it; and this clearly indicates that it is the

homologue and rudiment of the supracondyloid foramen of the lower animals. Prof. Turner estimates, as he

informs me, that it occurs in about one per cent. of recent skeletons. But if the occasional development of this

structure in man is, as seems probable, due to reversion, it is a return to a very ancient state of things, because

There is another foramen or perforation in the humerus, occasionally present in man, which may be called the

intercondyloid. This occurs, but not constantly, in various anthropoid and other apes (50. Mr. St. George

Mivart, 'Transactions Phil. Soc.' 1867, p. 310.), and likewise in many of the lower animals. It is remarkable

that this perforation seems to have been present in man much more frequently during ancient times than

recently. Mr. Busk (51. "On the Caves of Gibraltar," 'Transactions of the International Congress of

Prehistoric Archaeology,' Third Session, 1869, p. 159. Prof. Wyman has lately shewn (Fourth Annual Report,

Peabody Museum, 1871, p. 20), that this perforation is present in thirtyone per cent. of some human remains

from ancient mounds in the Western United States, and in Florida. It frequently occurs in the negro.) has

collected the following evidence on this head: Prof. Broca "noticed the perforation in four and a half per cent.

of the armbones collected in the 'Cimetiere du Sud,' at Paris; and in the Grotto of Orrony, the contents of

which are referred to the Bronze period, as many as eight humeri out of thirtytwo were perforated; but this

extraordinary proportion, he thinks, might be due to the cavern having been a sort of 'family vault.' Again, M.

Dupont found thirty per cent. of perforated bones in the caves of the Valley of the Lesse, belonging to the

Reindeer period; whilst M. Leguay, in a sort of dolmen at Argenteuil, observed twentyfive per cent. to be

perforated; and M. PrunerBey found twentysix per cent. in the same condition in bones from Vaureal. Nor

should it be left unnoticed that M. PrunerBey states that this condition is common in Guanche skeletons." It

is an interesting fact that ancient races, in this and several other cases, more frequently present structures

which resemble those of the lower animals than do the modern. One chief cause seems to be that the ancient

races stand somewhat nearer in the long line of descent to their remote animallike progenitors.

In man, the os coccyx, together with certain other vertebrae hereafter to be described, though functionless as

a tail, plainly represent this part in other vertebrate animals. At an early embryonic period it is free, and

projects beyond the lower extremities; as may be seen in the drawing (Fig. 1.) of a human embryo. Even after

birth it has been known, in certain rare and anomalous cases (52. Quatrefages has lately collected the

evidence on this subject. 'Revue des Cours Scientifiques,' 18671868, p. 625. In 1840 Fleischmann exhibited

a human foetus bearing a free tail, which, as is not always the case, included vertebral bodies; and this tail

was critically examined by the many anatomists present at the meeting of naturalists at Erlangen (see

Marshall in Niederlandischen Archiv fur Zoologie, December 1871).), to form a small external rudiment of a

tail. The os coccyx is short, usually including only four vertebrae, all anchylosed together: and these are in a

rudimentary condition, for they consist, with the exception of the basal one, of the centrum alone. (53. Owen,

'On the Nature of Limbs,' 1849, p. 114.) They are furnished with some small muscles; one of which, as I am

informed by Prof. Turner, has been expressly described by Theile as a rudimentary repetition of the extensor

The spinal cord in man extends only as far downwards as the last dorsal or first lumbar vertebra; but a

threadlike structure (the filum terminale) runs down the axis of the sacral part of the spinal canal, and even

along the back of the coccygeal bones. The upper part of this filament, as Prof. Turner informs me, is

undoubtedly homologous with the spinal cord; but the lower part apparently consists merely of the pia mater,

or vascular investing membrane. Even in this case the os coccyx may be said to possess a vestige of so

important a structure as the spinal cord, though no longer enclosed within a bony canal. The following fact,

for which I am also indebted to Prof. Turner, shews how closely the os coccyx corresponds with the true tail

in the lower animals: Luschka has recently discovered at the extremity of the coccygeal bones a very peculiar

convoluted body, which is continuous with the middle sacral artery; and this discovery led Krause and Meyer

to examine the tail of a monkey (Macacus), and of a cat, in both of which they found a similarly convoluted

The reproductive system offers various rudimentary structures; but these differ in one important respect from

the foregoing cases. Here we are not concerned with the vestige of a part which does not belong to the species

in an efficient state, but with a part efficient in the one sex, and represented in the other by a mere rudiment.

Nevertheless, the occurrence of such rudiments is as difficult to explain, on the belief of the separate creation

of each species, as in the foregoing cases. Hereafter I shall have to recur to these rudiments, and shall shew

that their presence generally depends merely on inheritance, that is, on parts acquired by one sex having been

partially transmitted to the other. I will in this place only give some instances of such rudiments. It is well

known that in the males of all mammals, including man, rudimentary mammae exist. These in several

instances have become well developed, and have yielded a copious supply of milk. Their essential identity in

the two sexes is likewise shewn by their occasional sympathetic enlargement in both during an attack of the

measles. The vesicula prostatica, which has been observed in many male mammals, is now universally

acknowledged to be the homologue of the female uterus, together with the connected passage. It is impossible

to read Leuckart's able description of this organ, and his reasoning, without admitting the justness of his

conclusion. This is especially clear in the case of those mammals in which the true female uterus bifurcates,

for in the males of these the vesicula likewise bifurcates. (54. Leuckart, in Todd's 'Cyclopaedia of Anatomy'

184952, vol. iv. p. 1415. In man this organ is only from three to six lines in length, but, like so many other

rudimentary parts, it is variable in development as well as in other characters.) Some other rudimentary

structures belonging to the reproductive system might have been here adduced. (55. See, on this subject,

The bearing of the three great classes of facts now given is unmistakeable. But it would be superfluous fully

to recapitulate the line of argument given in detail in my 'Origin of Species.' The homological construction of

the whole frame in the members of the same class is intelligible, if we admit their descent from a common

progenitor, together with their subsequent adaptation to diversified conditions. On any other view, the

similarity of pattern between the hand of a man or monkey, the foot of a horse, the flipper of a seal, the wing

of a bat, etc., is utterly inexplicable. (56. Prof. Bianconi, in a recently published work, illustrated by

admirable engravings ('La Theorie Darwinienne et la creation dite independante,' 1874), endeavours to shew

that homological structures, in the above and other cases, can be fully explained on mechanical principles, in

accordance with their uses. No one has shewn so well, how admirably such structures are adapted for their

final purpose; and this adaptation can, as I believe, be explained through natural selection. In considering the

wing of a bat, he brings forward (p. 218) what appears to me (to use Auguste Comte's words) a mere

metaphysical principle, namely, the preservation "in its integrity of the mammalian nature of the animal." In

only a few cases does he discuss rudiments, and then only those parts which are partially rudimentary, such

as the little hoofs of the pig and ox, which do not touch the ground; these he shews clearly to be of service to

the animal. It is unfortunate that he did not consider such cases as the minute teeth, which never cut through

the jaw in the ox, or the mammae of male quadrupeds, or the wings of certain beetles, existing under the

soldered wingcovers, or the vestiges of the pistil and stamens in various flowers, and many other such cases.

Although I greatly admire Prof. Bianconi's work, yet the belief now held by most naturalists seems to me left

unshaken, that homological structures are inexplicable on the principle of mere adaptation.) It is no scientific

explanation to assert that they have all been formed on the same ideal plan. With respect to development, we

can clearly understand, on the principle of variations supervening at a rather late embryonic period, and being

inherited at a corresponding period, how it is that the embryos of wonderfully different forms should still

retain, more or less perfectly, the structure of their common progenitor. No other explanation has ever been

given of the marvellous fact that the embryos of a man, dog, seal, bat, reptile, etc., can at first hardly be

distinguished from each other. In order to understand the existence of rudimentary organs, we have only to

suppose that a former progenitor possessed the parts in question in a perfect state, and that under changed

habits of life they became greatly reduced, either from simple disuse, or through the natural selection of those

individuals which were least encumbered with a superfluous part, aided by the other means previously

Thus we can understand how it has come to pass that man and all other vertebrate animals have been

constructed on the same general model, why they pass through the same early stages of development, and

why they retain certain rudiments in common. Consequently we ought frankly to admit their community of

descent: to take any other view, is to admit that our own structure, and that of all the animals around us, is a

mere snare laid to entrap our judgment. This conclusion is greatly strengthened, if we look to the members of

the whole animal series, and consider the evidence derived from their affinities or classification, their

geographical distribution and geological succession. It is only our natural prejudice, and that arrogance which

made our forefathers declare that they were descended from demigods, which leads us to demur to this

conclusion. But the time will before long come, when it will be thought wonderful that naturalists, who were

well acquainted with the comparative structure and development of man, and other mammals, should have

Variability of body and mind in manInheritanceCauses of variability Laws of variation the same in

man as in the lower animalsDirect action of the conditions of lifeEffects of the increased use and disuse

of parts Arrested developmentReversionCorrelated variationRate of increase Checks to

increaseNatural selectionMan the most dominant animal in the worldImportance of his corporeal

structureThe causes which have led to his becoming erectConsequent changes of structureDecrease

in size of the canine teethIncreased size and altered shape of the skullNakedness Absence of a

It is manifest that man is now subject to much variability. No two individuals of the same race are quite alike.

We may compare millions of faces, and each will be distinct. There is an equally great amount of diversity in

the proportions and dimensions of the various parts of the body; the length of the legs being one of the most

variable points. (1. 'Investigations in Military and Anthropological Statistics of American Soldiers,' by B.A.

Gould, 1869, p. 256.) Although in some quarters of the world an elongated skull, and in other quarters a short

skull prevails, yet there is great diversity of shape even within the limits of the same race, as with the

aborigines of America and South Australiathe latter a race "probably as pure and homogeneous in blood,

customs, and language as any in existence"and even with the inhabitants of so confined an area as the

Sandwich Islands. (2. With respect to the "Cranial forms of the American aborigines," see Dr. Aitken Meigs

in 'Proc. Acad. Nat. Sci.' Philadelphia, May 1868. On the Australians, see Huxley, in Lyell's 'Antiquity of

Man,' 1863, p. 87. On the Sandwich Islanders, Prof. J. Wyman, 'Observations on Crania,' Boston, 1868, p.

18.) An eminent dentist assures me that there is nearly as much diversity in the teeth as in the features. The

chief arteries so frequently run in abnormal courses, that it has been found useful for surgical purposes to

calculate from 1040 corpses how often each course prevails. (3. 'Anatomy of the Arteries,' by R. Quain.

Preface, vol. i. 1844.) The muscles are eminently variable: thus those of the foot were found by Prof. Turner

(4. 'Transactions of the Royal Society of Edinburgh,' vol. xxiv. pp. 175, 189.) not to be strictly alike in any

two out of fifty bodies; and in some the deviations were considerable. He adds, that the power of performing

the appropriate movements must have been modified in accordance with the several deviations. Mr. J. Wood

has recorded (5. 'Proceedings Royal Society,' 1867, p. 544; also 1868, pp. 483, 524. There is a previous

paper, 1866, p. 229.) the occurrence of 295 muscular variations in thirtysix subjects, and in another set of

the same number no less than 558 variations, those occurring on both sides of the body being only reckoned

as one. In the last set, not one body out of the thirtysix was "found totally wanting in departures from the

standard descriptions of the muscular system given in anatomical text books." A single body presented the

extraordinary number of twentyfive distinct abnormalities. The same muscle sometimes varies in many

ways: thus Prof. Macalister describes (6. 'Proc. R. Irish Academy,' vol. x. 1868, p. 141.) no less than twenty

The famous old anatomist, Wolff (7. 'Act. Acad. St. Petersburg,' 1778, part ii. p. 217.), insists that the internal

viscera are more variable than the external parts: Nulla particula est quae non aliter et aliter in aliis se habeat

hominibus. He has even written a treatise on the choice of typical examples of the viscera for representation.

A discussion on the beauideal of the liver, lungs, kidneys, etc., as of the human face divine, sounds strange

The variability or diversity of the mental faculties in men of the same race, not to mention the greater

differences between the men of distinct races, is so notorious that not a word need here be said. So it is with

the lower animals. All who have had charge of menageries admit this fact, and we see it plainly in our dogs

and other domestic animals. Brehm especially insists that each individual monkey of those which he kept

tame in Africa had its own peculiar disposition and temper: he mentions one baboon remarkable for its high

intelligence; and the keepers in the Zoological Gardens pointed out to me a monkey, belonging to the New

World division, equally remarkable for intelligence. Rengger, also, insists on the diversity in the various

mental characters of the monkeys of the same species which he kept in Paraguay; and this diversity, as he

adds, is partly innate, and partly the result of the manner in which they have been treated or educated. (8.

Brehm, 'Thierleben,' B. i. ss. 58, 87. Rengger, 'Saugethiere von Paraguay,' s. 57.)

I have elsewhere (9. 'Variation of Animals and Plants under Domestication,' vol. ii. chap. xii.) so fully

discussed the subject of Inheritance, that I need here add hardly anything. A greater number of facts have

been collected with respect to the transmission of the most trifling, as well as of the most important characters

in man, than in any of the lower animals; though the facts are copious enough with respect to the latter. So in

regard to mental qualities, their transmission is manifest in our dogs, horses, and other domestic animals.

Besides special tastes and habits, general intelligence, courage, bad and good temper, etc., are certainly

transmitted. With man we see similar facts in almost every family; and we now know, through the admirable

labours of Mr. Galton (10. 'Hereditary Genius: an Inquiry into its Laws and Consequences,' 1869.), that

genius which implies a wonderfully complex combination of high faculties, tends to be inherited; and, on the

other hand, it is too certain that insanity and deteriorated mental powers likewise run in families.

With respect to the causes of variability, we are in all cases very ignorant; but we can see that in man as in the

lower animals, they stand in some relation to the conditions to which each species has been exposed, during

several generations. Domesticated animals vary more than those in a state of nature; and this is apparently

due to the diversified and changing nature of the conditions to which they have been subjected. In this respect

the different races of man resemble domesticated animals, and so do the individuals of the same race, when

inhabiting a very wide area, like that of America. We see the influence of diversified conditions in the more

civilised nations; for the members belonging to different grades of rank, and following different occupations,

present a greater range of character than do the members of barbarous nations. But the uniformity of savages

has often been exaggerated, and in some cases can hardly be said to exist. (11. Mr. Bates remarks ('The

Naturalist on the Amazons,' 1863, vol. ii p. 159), with respect to the Indians of the same South American

tribe, "no two of them were at all similar in the shape of the head; one man had an oval visage with fine

features, and another was quite Mongolian in breadth and prominence of cheek, spread of nostrils, and

obliquity of eyes.") It is, nevertheless, an error to speak of man, even if we look only to the conditions to

which he has been exposed, as "far more domesticated" (12. Blumenbach, 'Treatises on Anthropology.' Eng.

translat., 1865, p. 205.) than any other animal. Some savage races, such as the Australians, are not exposed to

more diversified conditions than are many species which have a wide range. In another and much more

important respect, man differs widely from any strictly domesticated animal; for his breeding has never long

been controlled, either by methodical or unconscious selection. No race or body of men has been so

completely subjugated by other men, as that certain individuals should be preserved, and thus unconsciously

selected, from somehow excelling in utility to their masters. Nor have certain male and female individuals

been intentionally picked out and matched, except in the wellknown case of the Prussian grenadiers; and in

this case man obeyed, as might have been expected, the law of methodical selection; for it is asserted that

many tall men were reared in the villages inhabited by the grenadiers and their tall wives. In Sparta, also, a

form of selection was followed, for it was enacted that all children should be examined shortly after birth; the

wellformed and vigorous being preserved, the others left to perish. (13. Mitford's 'History of Greece,' vol. i.

p. 282. It appears also from a passage in Xenophon's 'Memorabilia,' B. ii. 4 (to which my attention has been

called by the Rev. J.N. Hoare), that it was a well recognised principle with the Greeks, that men ought to

select their wives with a view to the health and vigour of their children. The Grecian poet, Theognis, who

lived 550 B.C., clearly saw how important selection, if carefully applied, would be for the improvement of

mankind. He saw, likewise, that wealth often checks the proper action of sexual selection. He thus writes:

"With kine and horses, Kurnus! we proceed By reasonable rules, and choose a breed For profit and increase,

at any price: Of a sound stock, without defect or vice. But, in the daily matches that we make, The price is

everything: for money's sake, Men marry: women are in marriage given The churl or ruffian, that in wealth

has thriven, May match his offspring with the proudest race: Thus everything is mix'd, noble and base! If then

in outward manner, form, and mind, You find us a degraded, motley kind, Wonder no more, my friend! the

If we consider all the races of man as forming a single species, his range is enormous; but some separate

races, as the Americans and Polynesians, have very wide ranges. It is a wellknown law that widelyranging

species are much more variable than species with restricted ranges; and the variability of man may with more

truth be compared with that of widely ranging species, than with that of domesticated animals.

Not only does variability appear to be induced in man and the lower animals by the same general causes, but

in both the same parts of the body are affected in a closely analogous manner. This has been proved in such

full detail by Godron and Quatrefages, that I need here only refer to their works. (14. Godron, 'De l'Espece,'

1859, tom. ii. livre 3. Quatrefages, 'Unite de l'Espece Humaine,' 1861. Also Lectures on Anthropology, given

in the 'Revue des Cours Scientifiques,' 18661868.) Monstrosities, which graduate into slight variations, are

likewise so similar in man and the lower animals, that the same classification and the same terms can be used

for both, as has been shewn by Isidore Geoffroy St.Hilaire. (15. 'Hist. Gen. et Part. des Anomalies de

l'Organisation,' in three volumes, tom. i. 1832.) In my work on the variation of domestic animals, I have

attempted to arrange in a rude fashion the laws of variation under the following heads:The direct and

definite action of changed conditions, as exhibited by all or nearly all the individuals of the same species,

varying in the same manner under the same circumstances. The effects of the long continued use or disuse

of parts. The cohesion of homologous parts. The variability of multiple parts. Compensation of growth; but of

this law I have found no good instance in the case of man. The effects of the mechanical pressure of one part

on another; as of the pelvis on the cranium of the infant in the womb. Arrests of development, leading to the

diminution or suppression of parts. The reappearance of longlost characters through reversion. And lastly,

correlated variation. All these socalled laws apply equally to man and the lower animals; and most of them

even to plants. It would be superfluous here to discuss all of them (16. I have fully discussed these laws in my

'Variation of Animals and Plants under Domestication,' vol. ii. chap. xxii. and xxiii. M. J.P. Durand has lately

(1868) published a valuable essay, 'De l'Influence des Milieux,' etc. He lays much stress, in the case of plants,

on the nature of the soil.); but several are so important, that they must be treated at considerable length.

This is a most perplexing subject. It cannot be denied that changed conditions produce some, and

occasionally a considerable effect, on organisms of all kinds; and it seems at first probable that if sufficient

time were allowed this would be the invariable result. But I have failed to obtain clear evidence in favour of

this conclusion; and valid reasons may be urged on the other side, at least as far as the innumerable structures

are concerned, which are adapted for special ends. There can, however, be no doubt that changed conditions

induce an almost indefinite amount of fluctuating variability, by which the whole organisation is rendered in

In the United States, above 1,000,000 soldiers, who served in the late war, were measured, and the States in

which they were born and reared were recorded. (17. 'Investigations in Military and Anthrop. Statistics,' etc.,

1869, by B.A. Gould, pp. 93, 107, 126, 131, 134.) From this astonishing number of observations it is proved

that local influences of some kind act directly on stature; and we further learn that "the State where the

physical growth has in great measure taken place, and the State of birth, which indicates the ancestry, seem to

exert a marked influence on the stature." For instance, it is established, "that residence in the Western States,

during the years of growth, tends to produce increase of stature." On the other hand, it is certain that with

sailors, their life delays growth, as shewn "by the great difference between the statures of soldiers and sailors

at the ages of seventeen and eighteen years." Mr. B.A. Gould endeavoured to ascertain the nature of the

influences which thus act on stature; but he arrived only at negative results, namely that they did not relate to

climate, the elevation of the land, soil, nor even "in any controlling degree" to the abundance or the need of

the comforts of life. This latter conclusion is directly opposed to that arrived at by Villerme, from the

statistics of the height of the conscripts in different parts of France. When we compare the differences in

stature between the Polynesian chiefs and the lower orders within the same islands, or between the

inhabitants of the fertile volcanic and low barren coral islands of the same ocean (18. For the Polynesians, see

Prichard's 'Physical History of Mankind,' vol. v. 1847, pp. 145, 283. Also Godron, 'De l'Espece,' tom. ii. p.

289. There is also a remarkable difference in appearance between the closelyallied Hindoos inhabiting the

Upper Ganges and Bengal; see Elphinstone's 'History of India,' vol. i. p. 324.) or again between the Fuegians

on the eastern and western shores of their country, where the means of subsistence are very different, it is

scarcely possible to avoid the conclusion that better food and greater comfort do influence stature. But the

preceding statements shew how difficult it is to arrive at any precise result. Dr. Beddoe has lately proved that,

with the inhabitants of Britain, residence in towns and certain occupations have a deteriorating influence on

height; and he infers that the result is to a certain extent inherited, as is likewise the case in the United States.

Dr. Beddoe further believes that wherever a "race attains its maximum of physical development, it rises

highest in energy and moral vigour." (19. 'Memoirs, Anthropological Society,' vol. iii. 186769, pp. 561, 565,

Whether external conditions produce any other direct effect on man is not known. It might have been

expected that differences of climate would have had a marked influence, inasmuch as the lungs and kidneys

are brought into activity under a low temperature, and the liver and skin under a high one. (20. Dr.

Brakenridge, 'Theory of Diathesis,' 'Medical Times,' June 19 and July 17, 1869.) It was formerly thought that

the colour of the skin and the character of the hair were determined by light or heat; and although it can

hardly be denied that some effect is thus produced, almost all observers now agree that the effect has been

very small, even after exposure during many ages. But this subject will be more properly discussed when we

treat of the different races of mankind. With our domestic animals there are grounds for believing that cold

and damp directly affect the growth of the hair; but I have not met with any evidence on this head in the case

It is well known that use strengthens the muscles in the individual, and complete disuse, or the destruction of

the proper nerve, weakens them. When the eye is destroyed, the optic nerve often becomes atrophied. When

an artery is tied, the lateral channels increase not only in diameter, but in the thickness and strength of their

coats. When one kidney ceases to act from disease, the other increases in size, and does double work. Bones

increase not only in thickness, but in length, from carrying a greater weight. (21. I have given authorities for

these several statements in my 'Variation of Animals and Plants under Domestication,' vol. ii. pp. 297 300.

Dr. Jaeger, "Uber das Langenwachsthum der Knochen," 'Jenaischen Zeitschrift,' B. v. Heft. i.) Different

occupations, habitually followed, lead to changed proportions in various parts of the body. Thus it was

ascertained by the United States Commission (22. 'Investigations,' etc., by B.A. Gould, 1869, p. 288.) that the

legs of the sailors employed in the late war were longer by 0.217 of an inch than those of the soldiers, though

the sailors were on an average shorter men; whilst their arms were shorter by 1.09 of an inch, and therefore,

out of proportion, shorter in relation to their lesser height. This shortness of the arms is apparently due to

their greater use, and is an unexpected result: but sailors chiefly use their arms in pulling, and not in

supporting weights. With sailors, the girth of the neck and the depth of the instep are greater, whilst the

Whether the several foregoing modifications would become hereditary, if the same habits of life were

followed during many generations, is not known, but it is probable. Rengger (23. 'Saugethiere von Paraguay,'

1830, s. 4.) attributes the thin legs and thick arms of the Payaguas Indians to successive generations having

passed nearly their whole lives in canoes, with their lower extremities motionless. Other writers have come to

a similar conclusion in analogous cases. According to Cranz (24. 'History of Greenland,' Eng. translat., 1767,

vol. i. p. 230.), who lived for a long time with the Esquimaux, "the natives believe that ingenuity and

dexterity in sealcatching (their highest art and virtue) is hereditary; there is really something in it, for the

son of a celebrated sealcatcher will distinguish himself, though he lost his father in childhood." But in this

case it is mental aptitude, quite as much as bodily structure, which appears to be inherited. It is asserted that

the hands of English labourers are at birth larger than those of the gentry. (25. 'Intermarriage,' by Alex.

Walker, 1838, p. 377.) From the correlation which exists, at least in some cases (26. 'The Variation of

Animals under Domestication,' vol. i. p. 173.), between the development of the extremities and of the jaws, it

is possible that in those classes which do not labour much with their hands and feet, the jaws would be

reduced in size from this cause. That they are generally smaller in refined and civilised men than in

hardworking men or savages, is certain. But with savages, as Mr. Herbert Spencer (27. 'Principles of

Biology,' vol. i. p. 455.) has remarked, the greater use of the jaws in chewing coarse, uncooked food, would

act in a direct manner on the masticatory muscles, and on the bones to which they are attached. In infants,

long before birth, the skin on the soles of the feet is thicker than on any other part of the body; (28. Paget,

'Lectures on Surgical Pathology,' vol. ii, 1853, p. 209.) and it can hardly be doubted that this is due to the

It is familiar to every one that watchmakers and engravers are liable to be shortsighted, whilst men living

much out of doors, and especially savages, are generally longsighted. (29. It is a singular and unexpected

fact that sailors are inferior to landsmen in their mean distance of distinct vision. Dr. B.A. Gould ('Sanitary

Memoirs of the War of the Rebellion,' 1869, p. 530), has proved this to be the case; and he accounts for it by

the ordinary range of vision in sailors being "restricted to the length of the vessel and the height of the

masts.") Shortsight and longsight certainly tend to be inherited. (30. 'The Variation of Animals under

Domestication,' vol. i. p. 8.) The inferiority of Europeans, in comparison with savages, in eyesight and in the

other senses, is no doubt the accumulated and transmitted effect of lessened use during many generations; for

Rengger (31. 'Saugethiere von Paraguay,' s. 8, 10. I have had good opportunities for observing the

extraordinary power of eyesight in the Fuegians. See also Lawrence ('Lectures on Physiology,' etc., 1822, p.

404) on this same subject. M. GiraudTeulon has recently collected ('Revue des Cours Scientifiques,' 1870,

p. 625) a large and valuable body of evidence proving that the cause of shortsight, "C'est le travail assidu, de

pres.") states that he has repeatedly observed Europeans, who had been brought up and spent their whole

lives with the wild Indians, who nevertheless did not equal them in the sharpness of their senses. The same

naturalist observes that the cavities in the skull for the reception of the several sense organs are larger in the

American aborigines than in Europeans; and this probably indicates a corresponding difference in the

dimensions of the organs themselves. Blumenbach has also remarked on the large size of the nasal cavities in

the skulls of the American aborigines, and connects this fact with their remarkably acute power of smell. The

Mongolians of the plains of northern Asia, according to Pallas, have wonderfully perfect senses; and Prichard

believes that the great breadth of their skulls across the zygomas follows from their highlydeveloped sense

organs. (32. Prichard, 'Physical History of Mankind,' on the authority of Blumenbach, vol. i. 1851, p. 311; for

The Quechua Indians inhabit the lofty plateaux of Peru; and Alcide d'Orbigny states (33. Quoted by Prichard,

'Researches into the Physical History of Mankind,' vol. v. p. 463.) that, from continually breathing a highly

rarefied atmosphere, they have acquired chests and lungs of extraordinary dimensions. The cells, also, of the

lungs are larger and more numerous than in Europeans. These observations have been doubted, but Mr. D.

Forbes carefully measured many Aymaras, an allied race, living at the height of between 10,000 and 15,000

feet; and he informs me (34. Mr. Forbes' valuable paper is now published in the 'Journal of the Ethnological

Society of London,' new series, vol. ii. 1870, p.193.) that they differ conspicuously from the men of all other

races seen by him in the circumference and length of their bodies. In his table of measurements, the stature of

each man is taken at 1000, and the other measurements are reduced to this standard. It is here seen that the

extended arms of the Aymaras are shorter than those of Europeans, and much shorter than those of Negroes.

The legs are likewise shorter; and they present this remarkable peculiarity, that in every Aymara measured,

the femur is actually shorter than the tibia. On an average, the length of the femur to that of the tibia is as 211

to 252; whilst in two Europeans, measured at the same time, the femora to the tibiae were as 244 to 230; and

in three Negroes as 258 to 241. The humerus is likewise shorter relatively to the forearm. This shortening of

that part of the limb which is nearest to the body, appears to be, as suggested to me by Mr. Forbes, a case of

compensation in relation with the greatly increased length of the trunk. The Aymaras present some other

singular points of structure, for instance, the very small projection of the heel.

These men are so thoroughly acclimatised to their cold and lofty abode, that when formerly carried down by

the Spaniards to the low eastern plains, and when now tempted down by high wages to the goldwashings,

they suffer a frightful rate of mortality. Nevertheless Mr. Forbes found a few pure families which had

survived during two generations: and he observed that they still inherited their characteristic peculiarities. But

it was manifest, even without measurement, that these peculiarities had all decreased; and on measurement,

their bodies were found not to be so much elongated as those of the men on the high plateau; whilst their

femora had become somewhat lengthened, as had their tibiae, although in a less degree. The actual

measurements may be seen by consulting Mr. Forbes's memoir. From these observations, there can, I think,

be no doubt that residence during many generations at a great elevation tends, both directly and indirectly, to

induce inherited modifications in the proportions of the body. (35. Dr. Wilckens ('Landwirthschaft.

Wochenblatt,' No. 10, 1869) has lately published an interesting essay shewing how domestic animals, which

Although man may not have been much modified during the latter stages of his existence through the

increased or decreased use of parts, the facts now given shew that his liability in this respect has not been

lost; and we positively know that the same law holds good with the lower animals. Consequently we may

infer that when at a remote epoch the progenitors of man were in a transitional state, and were changing from

quadrupeds into bipeds, natural selection would probably have been greatly aided by the inherited effects of

There is a difference between arrested development and arrested growth, for parts in the former state continue

to grow whilst still retaining their early condition. Various monstrosities come under this head; and some, as

a cleft palate, are known to be occasionally inherited. It will suffice for our purpose to refer to the arrested

braindevelopment of microcephalous idiots, as described in Vogt's memoir. (36. 'Memoires sur les

Microcephales,' 1867, pp. 50, 125, 169, 171, 184198.) Their skulls are smaller, and the convolutions of the

brain are less complex than in normal men. The frontal sinus, or the projection over the eyebrows, is largely

developed, and the jaws are prognathous to an "effrayant" degree; so that these idiots somewhat resemble the

lower types of mankind. Their intelligence, and most of their mental faculties, are extremely feeble. They

cannot acquire the power of speech, and are wholly incapable of prolonged attention, but are much given to

imitation. They are strong and remarkably active, continually gambolling and jumping about, and making

grimaces. They often ascend stairs on allfours; and are curiously fond of climbing up furniture or trees. We

are thus reminded of the delight shewn by almost all boys in climbing trees; and this again reminds us how

lambs and kids, originally alpine animals, delight to frisk on any hillock, however small. Idiots also resemble

the lower animals in some other respects; thus several cases are recorded of their carefully smelling every

mouthful of food before eating it. One idiot is described as often using his mouth in aid of his hands, whilst

hunting for lice. They are often filthy in their habits, and have no sense of decency; and several cases have

been published of their bodies being remarkably hairy. (37. Prof. Laycock sums up the character of

brutelike idiots by calling them "theroid;" 'Journal of Mental Science,' July 1863. Dr. Scott ('The Deaf and

Dumb,' 2nd ed. 1870, p. 10) has often observed the imbecile smelling their food. See, on this same subject,

and on the hairiness of idiots, Dr. Maudsley, 'Body and Mind,' 1870, pp. 4651. Pinel has also given a

Many of the cases to be here given, might have been introduced under the last heading. When a structure is

arrested in its development, but still continues growing, until it closely resembles a corresponding structure in

some lower and adult member of the same group, it may in one sense be considered as a case of reversion.

The lower members in a group give us some idea how the common progenitor was probably constructed; and

it is hardly credible that a complex part, arrested at an early phase of embryonic development, should go on

growing so as ultimately to perform its proper function, unless it had acquired such power during some

earlier state of existence, when the present exceptional or arrested structure was normal. The simple brain of a

microcephalous idiot, in as far as it resembles that of an ape, may in this sense be said to offer a case of

reversion. (38. In my 'Variation of Animals under Domestication' (vol. ii. p. 57), I attributed the not very rare

cases of supernumerary mammae in women to reversion. I was led to this as a probable conclusion, by the

additional mammae being generally placed symmetrically on the breast; and more especially from one case,

in which a single efficient mamma occurred in the inguinal region of a woman, the daughter of another

woman with supernumerary mammae. But I now find (see, for instance, Prof. Preyer, 'Der Kampf um das

Dasein,' 1869, s. 45) that mammae erraticae, occur in other situations, as on the back, in the armpit, and on

the thigh; the mammae in this latter instance having given so much milk that the child was thus nourished.

The probability that the additional mammae are due to reversion is thus much weakened; nevertheless, it still

seems to me probable, because two pairs are often found symmetrically on the breast; and of this I myself

have received information in several cases. It is well known that some Lemurs normally have two pairs of

mammae on the breast. Five cases have been recorded of the presence of more than a pair of mammae (of

course rudimentary) in the male sex of mankind; see 'Journal of Anat. and Physiology,' 1872, p. 56, for a case

given by Dr. Handyside, in which two brothers exhibited this peculiarity; see also a paper by Dr. Bartels, in

'Reichert's and du BoisReymond's Archiv.,' 1872, p. 304. In one of the cases alluded to by Dr. Bartels, a

man bore five mammae, one being medial and placed above the navel; Meckel von Hemsbach thinks that this

latter case is illustrated by a medial mamma occurring in certain Cheiroptera. On the whole, we may well

doubt if additional mammae would ever have been developed in both sexes of mankind, had not his early

In the above work (vol. ii. p. 12), I also attributed, though with much hesitation, the frequent cases of

polydactylism in men and various animals to reversion. I was partly led to this through Prof. Owen's

statement, that some of the Ichthyopterygia possess more than five digits, and therefore, as I supposed, had

retained a primordial condition; but Prof. Gegenbaur ('Jenaischen Zeitschrift,' B. v. Heft 3, s. 341), disputes

Owen's conclusion. On the other hand, according to the opinion lately advanced by Dr. Gunther, on the

paddle of Ceratodus, which is provided with articulated bony rays on both sides of a central chain of bones,

there seems no great difficulty in admitting that six or more digits on one side, or on both sides, might

reappear through reversion. I am informed by Dr. Zouteveen that there is a case on record of a man having

twentyfour fingers and twentyfour toes! I was chiefly led to the conclusion that the presence of

supernumerary digits might be due to reversion from the fact that such digits, not only are strongly inherited,

but, as I then believed, had the power of regrowth after amputation, like the normal digits of the lower

vertebrata. But I have explained in the second edition of my Variation under Domestication why I now place

little reliance on the recorded cases of such regrowth. Nevertheless it deserves notice, inasmuch as arrested

development and reversion are intimately related processes; that various structures in an embryonic or

arrested condition, such as a cleft palate, bifid uterus, etc., are frequently accompanied by polydactylism. This

has been strongly insisted on by Meckel and Isidore Geoffroy St.Hilaire. But at present it is the safest course

to give up altogether the idea that there is any relation between the development of supernumerary digits and

reversion to some lowly organised progenitor of man.) There are other cases which come more strictly under

our present head of reversion. Certain structures, regularly occurring in the lower members of the group to

which man belongs, occasionally make their appearance in him, though not found in the normal human

embryo; or, if normally present in the human embryo, they become abnormally developed, although in a

manner which is normal in the lower members of the group. These remarks will be rendered clearer by the

In various mammals the uterus graduates from a double organ with two distinct orifices and two passages, as

in the marsupials, into a single organ, which is in no way double except from having a slight internal fold, as

in the higher apes and man. The rodents exhibit a perfect series of gradations between these two extreme

states. In all mammals the uterus is developed from two simple primitive tubes, the inferior portions of which

form the cornua; and it is in the words of Dr. Farre, "by the coalescence of the two cornua at their lower

extremities that the body of the uterus is formed in man; while in those animals in which no middle portion or

body exists, the cornua remain ununited. As the development of the uterus proceeds, the two cornua become

gradually shorter, until at length they are lost, or, as it were, absorbed into the body of the uterus." The angles

of the uterus are still produced into cornua, even in animals as high up in the scale as the lower apes and

Now in women, anomalous cases are not very infrequent, in which the mature uterus is furnished with

cornua, or is partially divided into two organs; and such cases, according to Owen, repeat "the grade of

concentrative development," attained by certain rodents. Here perhaps we have an instance of a simple arrest

of embryonic development, with subsequent growth and perfect functional development; for either side of the

partially double uterus is capable of performing the proper office of gestation. In other and rarer cases, two

distinct uterine cavities are formed, each having its proper orifice and passage. (39. See Dr. A. Farre's

wellknown article in the 'Cyclopaedia of Anatomy and Physiology,' vol. v. 1859, p. 642. Owen, 'Anatomy of

Vertebrates,' vol. iii. 1868, p. 687. Professor Turner, in 'Edinburgh Medical Journal,' February, 1865.) No

such stage is passed through during the ordinary development of the embryo; and it is difficult to believe,

though perhaps not impossible, that the two simple, minute, primitive tubes should know how (if such an

expression may be used) to grow into two distinct uteri, each with a wellconstructed orifice and passage,

and each furnished with numerous muscles, nerves, glands and vessels, if they had not formerly passed

through a similar course of development, as in the case of existing marsupials. No one will pretend that so

perfect a structure as the abnormal double uterus in woman could be the result of mere chance. But the

principle of reversion, by which a longlost structure is called back into existence, might serve as the guide

Professor Canestrini, after discussing the foregoing and various analogous cases, arrives at the same

conclusion as that just given. He adduces another instance, in the case of the malar bone (40. 'Annuario della

Soc. dei Naturalisti,' Modena, 1867, p. 83. Prof. Canestrini gives extracts on this subject from various

authorities. Laurillard remarks, that as he has found a complete similarity in the form, proportions, and

connection of the two malar bones in several human subjects and in certain apes, he cannot consider this

disposition of the parts as simply accidental. Another paper on this same anomaly has been published by Dr.

Saviotti in the 'Gazzetta delle Cliniche,' Turin, 1871, where he says that traces of the division may be detected

in about two per cent. of adult skulls; he also remarks that it more frequently occurs in prognathous skulls,

not of the Aryan race, than in others. See also G. Delorenzi on the same subject; 'Tre nuovi casi d'anomalia

dell' osso malare,' Torino, 1872. Also, E. Morselli, 'Sopra una rara anomalia dell' osso malare,' Modena,

1872. Still more recently Gruber has written a pamphlet on the division of this bone. I give these references

because a reviewer, without any grounds or scruples, has thrown doubts on my statements.), which, in some

of the Quadrumana and other mammals, normally consists of two portions. This is its condition in the human

foetus when two months old; and through arrested development, it sometimes remains thus in man when

adult, more especially in the lower prognathous races. Hence Canestrini concludes that some ancient

progenitor of man must have had this bone normally divided into two portions, which afterwards became

fused together. In man the frontal bone consists of a single piece, but in the embryo, and in children, and in

almost all the lower mammals, it consists of two pieces separated by a distinct suture. This suture

occasionally persists more or less distinctly in man after maturity; and more frequently in ancient than in

recent crania, especially, as Canestrini has observed, in those exhumed from the Drift, and belonging to the

brachycephalic type. Here again he comes to the same conclusion as in the analogous case of the malar

bones. In this, and other instances presently to be given, the cause of ancient races approaching the lower

animals in certain characters more frequently than do the modern races, appears to be, that the latter stand at a

somewhat greater distance in the long line of descent from their early semihuman progenitors.

Various other anomalies in man, more or less analogous to the foregoing, have been advanced by different

authors, as cases of reversion; but these seem not a little doubtful, for we have to descend extremely low in

the mammalian series, before we find such structures normally present. (41. A whole series of cases is given

by Isidore Geoffroy St.Hilaire, 'Hist. des Anomalies,' tom, iii, p. 437. A reviewer ('Journal of Anatomy and

Physiology,' 1871, p. 366) blames me much for not having discussed the numerous cases, which have been

recorded, of various parts arrested in their development. He says that, according to my theory, "every

transient condition of an organ, during its development, is not only a means to an end, but once was an end in

itself." This does not seem to me necessarily to hold good. Why should not variations occur during an early

period of development, having no relation to reversion; yet such variations might be preserved and

accumulated, if in any way serviceable, for instance, in shortening and simplifying the course of

development? And again, why should not injurious abnormalities, such as atrophied or hypertrophied parts,

which have no relation to a former state of existence, occur at an early period, as well as during maturity?)

In man, the canine teeth are perfectly efficient instruments for mastication. But their true canine character, as

Owen (42. 'Anatomy of Vertebrates,' vol. iii. 1868, p. 323.) remarks, "is indicated by the conical form of the

crown, which terminates in an obtuse point, is convex outward and flat or subconcave within, at the base of

which surface there is a feeble prominence. The conical form is best expressed in the Melanian races,

especially the Australian. The canine is more deeply implanted, and by a stronger fang than the incisors."

Nevertheless, this tooth no longer serves man as a special weapon for tearing his enemies or prey; it may,

therefore, as far as its proper function is concerned, be considered as rudimentary. In every large collection of

human skulls some may be found, as Haeckel (43. 'Generelle Morphologie,' 1866, B. ii. s. clv.) observes, with

the canine teeth projecting considerably beyond the others in the same manner as in the anthropomorphous

apes, but in a less degree. In these cases, open spaces between the teeth in the one jaw are left for the

reception of the canines of the opposite jaw. An interspace of this kind in a Kaffir skull, figured by Wagner,

is surprisingly wide. (44. Carl Vogt's 'Lectures on Man,' Eng. translat., 1864, p. 151.) Considering how few

are the ancient skulls which have been examined, compared to recent skulls, it is an interesting fact that in at

least three cases the canines project largely; and in the Naulette jaw they are spoken of as enormous. (45. C.

Carter Blake, on a jaw from La Naulette, 'Anthropological Review,' 1867, p. 295. Schaaffhausen, ibid. 1868,

Of the anthropomorphous apes the males alone have their canines fully developed; but in the female gorilla,

and in a less degree in the female orang, these teeth project considerably beyond the others; therefore the fact,

of which I have been assured, that women sometimes have considerably projecting canines, is no serious

objection to the belief that their occasional great development in man is a case of reversion to an apelike

progenitor. He who rejects with scorn the belief that the shape of his own canines, and their occasional great

development in other men, are due to our early forefathers having been provided with these formidable

weapons, will probably reveal, by sneering, the line of his descent. For though he no longer intends, nor has

the power, to use these teeth as weapons, he will unconsciously retract his "snarling muscles" (thus named by

Sir C. Bell) (46. The Anatomy of Expression, 1844, pp. 110, 131.), so as to expose them ready for action, like

Many muscles are occasionally developed in man, which are proper to the Quadrumana or other mammals.

Professor Vlacovich (47. Quoted by Prof. Canestrini in the 'Annuario della Soc. dei Naturalisti,' 1867, p. 90.)

examined forty male subjects, and found a muscle, called by him the ischio pubic, in nineteen of them; in

three others there was a ligament which represented this muscle; and in the remaining eighteen no trace of it.

In only two out of thirty female subjects was this muscle developed on both sides, but in three others the

rudimentary ligament was present. This muscle, therefore, appears to be much more common in the male than

in the female sex; and on the belief in the descent of man from some lower form, the fact is intelligible; for it

has been detected in several of the lower animals, and in all of these it serves exclusively to aid the male in

Mr. J. Wood, in his valuable series of papers (48. These papers deserve careful study by any one who desires

to learn how frequently our muscles vary, and in varying come to resemble those of the Quadrumana. The

following references relate to the few points touched on in my text: 'Proc. Royal Soc.' vol. xiv. 1865, pp.

379384; vol. xv. 1866, pp. 241, 242; vol. xv. 1867, p. 544; vol. xvi. 1868, p. 524. I may here add that Dr.

Murie and Mr. St. George Mivart have shewn in their Memoir on the Lemuroidea ('Transactions, Zoological

Society,' vol. vii. 1869, p. 96), how extraordinarily variable some of the muscles are in these animals, the

lowest members of the Primates. Gradations, also, in the muscles leading to structures found in animals still

lower in the scale, are numerous in the Lemuroidea.), has minutely described a vast number of muscular

variations in man, which resemble normal structures in the lower animals. The muscles which closely

resemble those regularly present in our nearest allies, the Quadrumana, are too numerous to be here even

specified. In a single male subject, having a strong bodily frame, and wellformed skull, no less than seven

muscular variations were observed, all of which plainly represented muscles proper to various kinds of apes.

This man, for instance, had on both sides of his neck a true and powerful "levator claviculae," such as is

found in all kinds of apes, and which is said to occur in about one out of sixty human subjects. (49. See also

Prof. Macalister in 'Proceedings, Royal Irish Academy,' vol. x. 1868, p. 124.) Again, this man had "a special

abductor of the metatarsal bone of the fifth digit, such as Professor Huxley and Mr. Flower have shewn to

exist uniformly in the higher and lower apes." I will give only two additional cases; the acromiobasilar

muscle is found in all mammals below man, and seems to be correlated with a quadrupedal gait, (50. Mr.

Champneys in 'Journal of Anatomy and Physiology,' Nov. 1871, p. 178.) and it occurs in about one out of

sixty human subjects. In the lower extremities Mr. Bradley (51. Ibid. May 1872, p. 421.) found an abductor

ossis metatarsi quinti in both feet of man; this muscle had not up to that time been recorded in mankind, but is

always present in the anthropomorphous apes. The muscles of the hands and armsparts which are so

eminently characteristic of manare extremely liable to vary, so as to resemble the corresponding muscles

in the lower animals. (52. Prof. Macalister (ibid. p. 121) has tabulated his observations, and finds that

muscular abnormalities are most frequent in the forearms, secondly, in the face, thirdly, in the foot, etc.)

Such resemblances are either perfect or imperfect; yet in the latter case they are manifestly of a transitional

nature. Certain variations are more common in man, and others in woman, without our being able to assign

any reason. Mr. Wood, after describing numerous variations, makes the following pregnant remark. "Notable

departures from the ordinary type of the muscular structures run in grooves or directions, which must be

taken to indicate some unknown factor, of much importance to a comprehensive knowledge of general and

scientific anatomy." (53. The Rev. Dr. Haughton, after giving ('Proc. R. Irish Academy,' June 27, 1864, p.

715) a remarkable case of variation in the human flexor pollicis longus, adds, "This remarkable example

shews that man may sometimes possess the arrangement of tendons of thumb and fingers characteristic of the

macaque; but whether such a case should be regarded as a macaque passing upwards into a man, or a man

passing downwards into a macaque, or as a congenital freak of nature, I cannot undertake to say." It is

satisfactory to hear so capable an anatomist, and so embittered an opponent of evolutionism, admitting even

the possibility of either of his first propositions. Prof. Macalister has also described ('Proceedings Royal Irish

Academy,' vol. x. 1864, p. 138) variations in the flexor pollicis longus, remarkable from their relations to the

That this unknown factor is reversion to a former state of existence may be admitted as in the highest degree

probable. (54. Since the first edition of this book appeared, Mr. Wood has published another memoir in the

Philosophical Transactions, 1870, p. 83, on the varieties of the muscles of the human neck, shoulder, and

chest. He here shews how extremely variable these muscles are, and how often and how closely the variations

resemble the normal muscles of the lower animals. He sums up by remarking, "It will be enough for my

purpose if I have succeeded in shewing the more important forms which, when occurring as varieties in the

human subject, tend to exhibit in a sufficiently marked manner what may be considered as proofs and

examples of the Darwinian principle of reversion, or law of inheritance, in this department of anatomical

science.") It is quite incredible that a man should through mere accident abnormally resemble certain apes in

no less than seven of his muscles, if there had been no genetic connection between them. On the other hand,

if man is descended from some apelike creature, no valid reason can be assigned why certain muscles

should not suddenly reappear after an interval of many thousand generations, in the same manner as with

horses, asses, and mules, dark coloured stripes suddenly reappear on the legs, and shoulders, after an

These various cases of reversion are so closely related to those of rudimentary organs given in the first

chapter, that many of them might have been indifferently introduced either there or here. Thus a human

uterus furnished with cornua may be said to represent, in a rudimentary condition, the same organ in its

normal state in certain mammals. Some parts which are rudimentary in man, as the os coccyx in both sexes,

and the mammae in the male sex, are always present; whilst others, such as the supracondyloid foramen, only

occasionally appear, and therefore might have been introduced under the head of reversion. These several

reversionary structures, as well as the strictly rudimentary ones, reveal the descent of man from some lower

In man, as in the lower animals, many structures are so intimately related, that when one part varies so does

another, without our being able, in most cases, to assign any reason. We cannot say whether the one part

governs the other, or whether both are governed by some earlier developed part. Various monstrosities, as I.

Geoffroy repeatedly insists, are thus intimately connected. Homologous structures are particularly liable to

change together, as we see on the opposite sides of the body, and in the upper and lower extremities. Meckel

long ago remarked, that when the muscles of the arm depart from their proper type, they almost always

imitate those of the leg; and so, conversely, with the muscles of the legs. The organs of sight and hearing, the

teeth and hair, the colour of the skin and of the hair, colour and constitution, are more or less correlated. (55.

The authorities for these several statements are given in my 'Variation of Animals under Domestication,' vol.

ii. pp. 320335.) Professor Schaaffhausen first drew attention to the relation apparently existing between a

muscular frame and the stronglypronounced supraorbital ridges, which are so characteristic of the lower

Besides the variations which can be grouped with more or less probability under the foregoing heads, there is

a large class of variations which may be provisionally called spontaneous, for to our ignorance they appear to

arise without any exciting cause. It can, however, be shewn that such variations, whether consisting of slight

individual differences, or of stronglymarked and abrupt deviations of structure, depend much more on the

constitution of the organism than on the nature of the conditions to which it has been subjected. (56. This

whole subject has been discussed in chap. xxiii. vol. ii. of my 'Variation of Animals and Plants under

Civilised populations have been known under favourable conditions, as in the United States, to double their

numbers in twentyfive years; and, according to a calculation, by Euler, this might occur in a little over

twelve years. (57. See the ever memorable 'Essay on the Principle of Population,' by the Rev. T. Malthus, vol.

i. 1826. pp. 6, 517.) At the former rate, the present population of the United States (thirty millions), would in

657 years cover the whole terraqueous globe so thickly, that four men would have to stand on each square

yard of surface. The primary or fundamental check to the continued increase of man is the difficulty of

gaining subsistence, and of living in comfort. We may infer that this is the case from what we see, for

instance, in the United States, where subsistence is easy, and there is plenty of room. If such means were

suddenly doubled in Great Britain, our number would be quickly doubled. With civilised nations this primary

check acts chiefly by restraining marriages. The greater deathrate of infants in the poorest classes is also

very important; as well as the greater mortality, from various diseases, of the inhabitants of crowded and

miserable houses, at all ages. The effects of severe epidemics and wars are soon counterbalanced, and more

than counterbalanced, in nations placed under favourable conditions. Emigration also comes in aid as a

There is reason to suspect, as Malthus has remarked, that the reproductive power is actually less in barbarous,

than in civilised races. We know nothing positively on this head, for with savages no census has been taken;

but from the concurrent testimony of missionaries, and of others who have long resided with such people, it

appears that their families are usually small, and large ones rare. This may be partly accounted for, as it is

believed, by the women suckling their infants during a long time; but it is highly probable that savages, who

often suffer much hardship, and who do not obtain so much nutritious food as civilised men, would be

actually less prolific. I have shewn in a former work (58. 'Variation of Animals and Plants under

Domestication,' vol ii. pp. 111113, 163.), that all our domesticated quadrupeds and birds, and all our

cultivated plants, are more fertile than the corresponding species in a state of nature. It is no valid objection to

this conclusion that animals suddenly supplied with an excess of food, or when grown very fat; and that most

plants on sudden removal from very poor to very rich soil, are rendered more or less sterile. We might,

therefore, expect that civilised men, who in one sense are highly domesticated, would be more prolific than

wild men. It is also probable that the increased fertility of civilised nations would become, as with our

domestic animals, an inherited character: it is at least known that with mankind a tendency to produce twins

runs in families. (59. Mr. Sedgwick, 'British and Foreign MedicoChirurgical Review,' July 1863, p. 170.)

Notwithstanding that savages appear to be less prolific than civilised people, they would no doubt rapidly

increase if their numbers were not by some means rigidly kept down. The Santali, or hilltribes of India, have

recently afforded a good illustration of this fact; for, as shewn by Mr. Hunter (60. 'The Annals of Rural

Bengal,' by W.W. Hunter, 1868, p. 259.), they have increased at an extraordinary rate since vaccination has

been introduced, other pestilences mitigated, and war sternly repressed. This increase, however, would not

have been possible had not these rude people spread into the adjoining districts, and worked for hire. Savages

almost always marry; yet there is some prudential restraint, for they do not commonly marry at the earliest

possible age. The young men are often required to shew that they can support a wife; and they generally have

first to earn the price with which to purchase her from her parents. With savages the difficulty of obtaining

subsistence occasionally limits their number in a much more direct manner than with civilised people, for all

tribes periodically suffer from severe famines. At such times savages are forced to devour much bad food,

and their health can hardly fail to be injured. Many accounts have been published of their protruding

stomachs and emaciated limbs after and during famines. They are then, also, compelled to wander much, and,

as I was assured in Australia, their infants perish in large numbers. As famines are periodical, depending

chiefly on extreme seasons, all tribes must fluctuate in number. They cannot steadily and regularly increase,

as there is no artificial increase in the supply of food. Savages, when hard pressed, encroach on each other's

territories, and war is the result; but they are indeed almost always at war with their neighbours. They are

liable to many accidents on land and water in their search for food; and in some countries they suffer much

from the larger beasts of prey. Even in India, districts have been depopulated by the ravages of tigers.

Malthus has discussed these several checks, but he does not lay stress enough on what is probably the most

important of all, namely infanticide, especially of female infants, and the habit of procuring abortion. These

practices now prevail in many quarters of the world; and infanticide seems formerly to have prevailed, as Mr.

M'Lennan (61. 'Primitive Marriage,' 1865.) has shewn, on a still more extensive scale. These practices appear

to have originated in savages recognising the difficulty, or rather the impossibility of supporting all the

infants that are born. Licentiousness may also be added to the foregoing checks; but this does not follow from

failing means of subsistence; though there is reason to believe that in some cases (as in Japan) it has been

If we look back to an extremely remote epoch, before man had arrived at the dignity of manhood, he would

have been guided more by instinct and less by reason than are the lowest savages at the present time. Our

early semi human progenitors would not have practised infanticide or polyandry; for the instincts of the

lower animals are never so perverted (62. A writer in the 'Spectator' (March 12, 1871, p. 320) comments as

follows on this passage:"Mr. Darwin finds himself compelled to reintroduce a new doctrine of the fall of

man. He shews that the instincts of the higher animals are far nobler than the habits of savage races of men,

and he finds himself, therefore, compelled to reintroduce,in a form of the substantial orthodoxy of which

he appears to be quite unconscious,and to introduce as a scientific hypothesis the doctrine that man's gain

of KNOWLEDGE was the cause of a temporary but longenduring moral deterioration as indicated by the

many foul customs, especially as to marriage, of savage tribes. What does the Jewish tradition of the moral

degeneration of man through his snatching at a knowledge forbidden him by his highest instinct assert

beyond this?") as to lead them regularly to destroy their own offspring, or to be quite devoid of jealousy.

There would have been no prudential restraint from marriage, and the sexes would have freely united at an

early age. Hence the progenitors of man would have tended to increase rapidly; but checks of some kind,

either periodical or constant, must have kept down their numbers, even more severely than with existing

savages. What the precise nature of these checks were, we cannot say, any more than with most other

animals. We know that horses and cattle, which are not extremely prolific animals, when first turned loose in

South America, increased at an enormous rate. The elephant, the slowest breeder of all known animals, would

in a few thousand years stock the whole world. The increase of every species of monkey must be checked by

some means; but not, as Brehm remarks, by the attacks of beasts of prey. No one will assume that the actual

power of reproduction in the wild horses and cattle of America, was at first in any sensible degree increased;

or that, as each district became fully stocked, this same power was diminished. No doubt, in this case, and in

all others, many checks concur, and different checks under different circumstances; periodical dearths,

depending on unfavourable seasons, being probably the most important of all. So it will have been with the

We have now seen that man is variable in body and mind; and that the variations are induced, either directly

or indirectly, by the same general causes, and obey the same general laws, as with the lower animals. Man

has spread widely over the face of the earth, and must have been exposed, during his incessant migrations

(63. See some good remarks to this effect by W. Stanley Jevons, "A Deduction from Darwin's Theory,"

'Nature,' 1869, p. 231.), to the most diversified conditions. The inhabitants of Tierra del Fuego, the Cape of

Good Hope, and Tasmania in the one hemisphere, and of the arctic regions in the other, must have passed

through many climates, and changed their habits many times, before they reached their present homes. (64.

Latham, 'Man and his Migrations,' 1851, p. 135.) The early progenitors of man must also have tended, like all

other animals, to have increased beyond their means of subsistence; they must, therefore, occasionally have

been exposed to a struggle for existence, and consequently to the rigid law of natural selection. Beneficial

variations of all kinds will thus, either occasionally or habitually, have been preserved and injurious ones

eliminated. I do not refer to stronglymarked deviations of structure, which occur only at long intervals of

time, but to mere individual differences. We know, for instance, that the muscles of our hands and feet, which

determine our powers of movement, are liable, like those of the lower animals, (65. Messrs. Murie and

Mivart in their 'Anatomy of the Lemuroidea' ('Transact. Zoolog. Soc.' vol. vii. 1869, pp. 9698) say, "some

muscles are so irregular in their distribution that they cannot be well classed in any of the above groups."

These muscles differ even on the opposite sides of the same individual.) to incessant variability. If then the

progenitors of man inhabiting any district, especially one undergoing some change in its conditions, were

divided into two equal bodies, the one half which included all the individuals best adapted by their powers of

movement for gaining subsistence, or for defending themselves, would on an average survive in greater

numbers, and procreate more offspring than the other and less well endowed half.

Man in the rudest state in which he now exists is the most dominant animal that has ever appeared on this

earth. He has spread more widely than any other highly organised form: and all others have yielded before

him. He manifestly owes this immense superiority to his intellectual faculties, to his social habits, which lead

him to aid and defend his fellows, and to his corporeal structure. The supreme importance of these characters

has been proved by the final arbitrament of the battle for life. Through his powers of intellect, articulate

language has been evolved; and on this his wonderful advancement has mainly depended. As Mr. Chauncey

Wright remarks (66. Limits of Natural Selection, 'North American Review,' Oct. 1870, p. 295.): "a

psychological analysis of the faculty of language shews, that even the smallest proficiency in it might require

more brain power than the greatest proficiency in any other direction." He has invented and is able to use

various weapons, tools, traps, etc., with which he defends himself, kills or catches prey, and otherwise obtains

food. He has made rafts or canoes for fishing or crossing over to neighbouring fertile islands. He has

discovered the art of making fire, by which hard and stringy roots can be rendered digestible, and poisonous

roots or herbs innocuous. This discovery of fire, probably the greatest ever made by man, excepting language,

dates from before the dawn of history. These several inventions, by which man in the rudest state has become

so preeminent, are the direct results of the development of his powers of observation, memory, curiosity,

imagination, and reason. I cannot, therefore, understand how it is that Mr. Wallace (67. 'Quarterly Review,'

April 1869, p. 392. This subject is more fully discussed in Mr. Wallace's 'Contributions to the Theory of

Natural Selection,' 1870, in which all the essays referred to in this work are republished. The 'Essay on

Man,' has been ably criticised by Prof. Claparede, one of the most distinguished zoologists in Europe, in an

article published in the 'Bibliotheque Universelle,' June 1870. The remark quoted in my text will surprise

every one who has read Mr. Wallace's celebrated paper on 'The Origin of Human Races Deduced from the

Theory of Natural Selection,' originally published in the 'Anthropological Review,' May 1864, p. clviii. I

cannot here resist quoting a most just remark by Sir J. Lubbock ('Prehistoric Times,' 1865, p. 479) in

reference to this paper, namely, that Mr. Wallace, "with characteristic unselfishness, ascribes it (i.e. the idea

of natural selection) unreservedly to Mr. Darwin, although, as is well known, he struck out the idea

independently, and published it, though not with the same elaboration, at the same time.") maintains, that

"natural selection could only have endowed the savage with a brain a little superior to that of an ape."

Although the intellectual powers and social habits of man are of paramount importance to him, we must not

underrate the importance of his bodily structure, to which subject the remainder of this chapter will be

devoted; the development of the intellectual and social or moral faculties being discussed in a later chapter.

Even to hammer with precision is no easy matter, as every one who has tried to learn carpentry will admit. To

throw a stone with as true an aim as a Fuegian in defending himself, or in killing birds, requires the most

consummate perfection in the correlated action of the muscles of the hand, arm, and shoulder, and, further, a

fine sense of touch. In throwing a stone or spear, and in many other actions, a man must stand firmly on his

feet; and this again demands the perfect coadaptation of numerous muscles. To chip a flint into the rudest

tool, or to form a barbed spear or hook from a bone, demands the use of a perfect hand; for, as a most capable

judge, Mr. Schoolcraft (68. Quoted by Mr. Lawson Tait in his 'Law of Natural Selection,' 'Dublin Quarterly

Journal of Medical Science,' Feb. 1869. Dr. Keller is likewise quoted to the same effect.), remarks, the

shaping fragments of stone into knives, lances, or arrowheads, shews "extraordinary ability and long

practice." This is to a great extent proved by the fact that primeval men practised a division of labour; each

man did not manufacture his own flint tools or rude pottery, but certain individuals appear to have devoted

themselves to such work, no doubt receiving in exchange the produce of the chase. Archaeologists are

convinced that an enormous interval of time elapsed before our ancestors thought of grinding chipped flints

into smooth tools. One can hardly doubt, that a manlike animal who possessed a hand and arm sufficiently

perfect to throw a stone with precision, or to form a flint into a rude tool, could, with sufficient practice, as far

as mechanical skill alone is concerned, make almost anything which a civilised man can make. The structure

of the hand in this respect may be compared with that of the vocal organs, which in the apes are used for

uttering various signalcries, or, as in one genus, musical cadences; but in man the closely similar vocal

organs have become adapted through the inherited effects of use for the utterance of articulate language.

Turning now to the nearest allies of men, and therefore to the best representatives of our early progenitors, we

find that the hands of the Quadrumana are constructed on the same general pattern as our own, but are far less

perfectly adapted for diversified uses. Their hands do not serve for locomotion so well as the feet of a dog; as

may be seen in such monkeys as the chimpanzee and orang, which walk on the outer margins of the palms, or

on the knuckles. (69. Owen, 'Anatomy of Vertebrates,' vol. iii. p. 71.) Their hands, however, are admirably

adapted for climbing trees. Monkeys seize thin branches or ropes, with the thumb on one side and the fingers

and palm on the other, in the same manner as we do. They can thus also lift rather large objects, such as the

neck of a bottle, to their mouths. Baboons turn over stones, and scratch up roots with their hands. They seize

nuts, insects, or other small objects with the thumb in opposition to the fingers, and no doubt they thus extract

eggs and young from the nests of birds. American monkeys beat the wild oranges on the branches until the

rind is cracked, and then tear it off with the fingers of the two hands. In a wild state they break open hard

fruits with stones. Other monkeys open musselshells with the two thumbs. With their fingers they pull out

thorns and burs, and hunt for each other's parasites. They roll down stones, or throw them at their enemies:

nevertheless, they are clumsy in these various actions, and, as I have myself seen, are quite unable to throw a

It seems to me far from true that because "objects are grasped clumsily" by monkeys, "a much less

specialised organ of prehension" would have served them (70. 'Quarterly Review,' April 1869, p. 392.)

equally well with their present hands. On the contrary, I see no reason to doubt that more perfectly

constructed hands would have been an advantage to them, provided that they were not thus rendered less

fitted for climbing trees. We may suspect that a hand as perfect as that of man would have been

disadvantageous for climbing; for the most arboreal monkeys in the world, namely, Ateles in America,

Colobus in Africa, and Hylobates in Asia, are either thumbless, or their toes partially cohere, so that their

limbs are converted into mere grasping hooks. (71. In Hylobates syndactylus, as the name expresses, two of

the toes regularly cohere; and this, as Mr. Blyth informs me, is occasionally the case with the toes of H.

agilis, lar, and leuciscus. Colobus is strictly arboreal and extraordinarily active (Brehm, 'Thierleben,' B. i. s.

50), but whether a better climber than the species of the allied genera, I do not know. It deserves notice that

the feet of the sloths, the most arboreal animals in the world, are wonderfully hook like.

As soon as some ancient member in the great series of the Primates came to be less arboreal, owing to a

change in its manner of procuring subsistence, or to some change in the surrounding conditions, its habitual

manner of progression would have been modified: and thus it would have been rendered more strictly

quadrupedal or bipedal. Baboons frequent hilly and rocky districts, and only from necessity climb high trees

(72. Brehm, 'Thierleben,' B. i. s. 80.); and they have acquired almost the gait of a dog. Man alone has become

a biped; and we can, I think, partly see how he has come to assume his erect attitude, which forms one of his

most conspicuous characters. Man could not have attained his present dominant position in the world without

the use of his hands, which are so admirably adapted to act in obedience to his will. Sir C. Bell (73. 'The

Hand,' etc., 'Bridgewater Treatise,' 1833, p. 38.) insists that "the hand supplies all instruments, and by its

correspondence with the intellect gives him universal dominion." But the hands and arms could hardly have

become perfect enough to have manufactured weapons, or to have hurled stones and spears with a true aim,

as long as they were habitually used for locomotion and for supporting the whole weight of the body, or, as

before remarked, so long as they were especially fitted for climbing trees. Such rough treatment would also

have blunted the sense of touch, on which their delicate use largely depends. From these causes alone it

would have been an advantage to man to become a biped; but for many actions it is indispensable that the

arms and whole upper part of the body should be free; and he must for this end stand firmly on his feet. To

gain this great advantage, the feet have been rendered flat; and the great toe has been peculiarly modified,

though this has entailed the almost complete loss of its power of prehension. It accords with the principle of

the division of physiological labour, prevailing throughout the animal kingdom, that as the hands became

perfected for prehension, the feet should have become perfected for support and locomotion. With some

savages, however, the foot has not altogether lost its prehensile power, as shewn by their manner of climbing

trees, and of using them in other ways. (74. Haeckel has an excellent discussion on the steps by which man

became a biped: 'Naturliche Schopfungsgeschicte,' 1868, s. 507. Dr. Buchner ('Conferences sur la Theorie

Darwinienne,' 1869, p. 135) has given good cases of the use of the foot as a prehensile organ by man; and has

also written on the manner of progression of the higher apes, to which I allude in the following paragraph: see

If it be an advantage to man to stand firmly on his feet and to have his hands and arms free, of which, from

his preeminent success in the battle of life there can be no doubt, then I can see no reason why it should not

have been advantageous to the progenitors of man to have become more and more erect or bipedal. They

would thus have been better able to defend themselves with stones or clubs, to attack their prey, or otherwise

to obtain food. The best built individuals would in the long run have succeeded best, and have survived in

larger numbers. If the gorilla and a few allied forms had become extinct, it might have been argued, with

great force and apparent truth, that an animal could not have been gradually converted from a quadruped into

a biped, as all the individuals in an intermediate condition would have been miserably illfitted for

progression. But we know (and this is well worthy of reflection) that the anthropomorphous apes are now

actually in an intermediate condition; and no one doubts that they are on the whole well adapted for their

conditions of life. Thus the gorilla runs with a sidelong shambling gait, but more commonly progresses by

resting on its bent hands. The longarmed apes occasionally use their arms like crutches, swinging their

bodies forward between them, and some kinds of Hylobates, without having been taught, can walk or run

upright with tolerable quickness; yet they move awkwardly, and much less securely than man. We see, in

short, in existing monkeys a manner of progression intermediate between that of a quadruped and a biped;

but, as an unprejudiced judge (75. Prof. Broca, La Constitution des Vertebres caudales; 'La Revue

d'Anthropologie,' 1872, p. 26, (separate copy).) insists, the anthropomorphous apes approach in structure

As the progenitors of man became more and more erect, with their hands and arms more and more modified

for prehension and other purposes, with their feet and legs at the same time transformed for firm support and

progression, endless other changes of structure would have become necessary. The pelvis would have to be

broadened, the spine peculiarly curved, and the head fixed in an altered position, all which changes have been

attained by man. Prof. Schaaffhausen (76. 'On the Primitive Form of the Skull,' translated in 'Anthropological

Review,' Oct. 1868, p. 428. Owen ('Anatomy of Vertebrates,' vol. ii. 1866, p. 551) on the mastoid processes

in the higher apes.) maintains that "the powerful mastoid processes of the human skull are the result of his

erect position;" and these processes are absent in the orang, chimpanzee, etc., and are smaller in the gorilla

than in man. Various other structures, which appear connected with man's erect position, might here have

been added. It is very difficult to decide how far these correlated modifications are the result of natural

selection, and how far of the inherited effects of the increased use of certain parts, or of the action of one part

on another. No doubt these means of change often cooperate: thus when certain muscles, and the crests of

bone to which they are attached, become enlarged by habitual use, this shews that certain actions are

habitually performed and must be serviceable. Hence the individuals which performed them best, would tend

The free use of the arms and hands, partly the cause and partly the result of man's erect position, appears to

have led in an indirect manner to other modifications of structure. The early male forefathers of man were, as

previously stated, probably furnished with great canine teeth; but as they gradually acquired the habit of using

stones, clubs, or other weapons, for fighting with their enemies or rivals, they would use their jaws and teeth

less and less. In this case, the jaws, together with the teeth, would become reduced in size, as we may feel

almost sure from innumerable analogous cases. In a future chapter we shall meet with a closely parallel case,

in the reduction or complete disappearance of the canine teeth in male ruminants, apparently in relation with

the development of their horns; and in horses, in relation to their habit of fighting with their incisor teeth and

In the adult male anthropomorphous apes, as Rutimeyer (77. 'Die Grenzen der Thierwelt, eine Betrachtung zu

Darwin's Lehre,' 1868, s. 51.), and others, have insisted, it is the effect on the skull of the great development

of the jawmuscles that causes it to differ so greatly in many respects from that of man, and has given to

these animals "a truly frightful physiognomy." Therefore, as the jaws and teeth in man's progenitors gradually

become reduced in size, the adult skull would have come to resemble more and more that of existing man. As

we shall hereafter see, a great reduction of the canine teeth in the males would almost certainly affect the

As the various mental faculties gradually developed themselves the brain would almost certainly become

larger. No one, I presume, doubts that the large proportion which the size of man's brain bears to his body,

compared to the same proportion in the gorilla or orang, is closely connected with his higher mental powers.

We meet with closely analogous facts with insects, for in ants the cerebral ganglia are of extraordinary

dimensions, and in all the Hymenoptera these ganglia are many times larger than in the less intelligent orders,

such as beetles. (78. Dujardin, 'Annales des Sciences Nat.' 3rd series, Zoolog., tom. xiv. 1850, p. 203. See

also Mr. Lowne, 'Anatomy and Phys. of the Musca vomitoria,' 1870, p. 14. My son, Mr. F. Darwin, dissected

for me the cerebral ganglia of the Formica rufa.) On the other hand, no one supposes that the intellect of any

two animals or of any two men can be accurately gauged by the cubic contents of their skulls. It is certain that

there may be extraordinary mental activity with an extremely small absolute mass of nervous matter: thus the

wonderfully diversified instincts, mental powers, and affections of ants are notorious, yet their cerebral

ganglia are not so large as the quarter of a small pin's head. Under this point of view, the brain of an ant is

one of the most marvellous atoms of matter in the world, perhaps more so than the brain of a man.

The belief that there exists in man some close relation between the size of the brain and the development of

the intellectual faculties is supported by the comparison of the skulls of savage and civilised races, of ancient

and modern people, and by the analogy of the whole vertebrate series. Dr. J. Barnard Davis has proved (79.

'Philosophical Transactions,' 1869, p. 513.), by many careful measurements, that the mean internal capacity

of the skull in Europeans is 92.3 cubic inches; in Americans 87.5; in Asiatics 87.1; and in Australians only

81.9 cubic inches. Professor Broca (80. 'Les Selections,' M. P. Broca, 'Revue d'Anthropologies,' 1873; see

also, as quoted in C. Vogt's 'Lectures on Man,' Engl. translat., 1864, pp. 88, 90. Prichard, 'Physical History of

Mankind,' vol. i. 1838, p. 305.) found that the nineteenth century skulls from graves in Paris were larger than

those from vaults of the twelfth century, in the proportion of 1484 to 1426; and that the increased size, as

ascertained by measurements, was exclusively in the frontal part of the skullthe seat of the intellectual

faculties. Prichard is persuaded that the present inhabitants of Britain have "much more capacious

braincases" than the ancient inhabitants. Nevertheless, it must be admitted that some skulls of very high

antiquity, such as the famous one of Neanderthal, are well developed and capacious. (81. In the interesting

article just referred to, Prof. Broca has well remarked, that in civilised nations, the average capacity of the

skull must be lowered by the preservation of a considerable number of individuals, weak in mind and body,

who would have been promptly eliminated in the savage state. On the other hand, with savages, the average

includes only the more capable individuals, who have been able to survive under extremely hard conditions

of life. Broca thus explains the otherwise inexplicable fact, that the mean capacity of the skull of the ancient

Troglodytes of Lozere is greater than that of modern Frenchmen.) With respect to the lower animals, M.E.

Lartet (82. 'Comptesrendus des Sciences,' etc., June 1, 1868.), by comparing the crania of tertiary and recent

mammals belonging to the same groups, has come to the remarkable conclusion that the brain is generally

larger and the convolutions are more complex in the more recent forms. On the other hand, I have shewn (83.

The 'Variation of Animals and Plants under Domestication,' vol. i. pp. 124129.) that the brains of domestic

rabbits are considerably reduced in bulk, in comparison with those of the wild rabbit or hare; and this may be

attributed to their having been closely confined during many generations, so that they have exerted their

The gradually increasing weight of the brain and skull in man must have influenced the development of the

supporting spinal column, more especially whilst he was becoming erect. As this change of position was

being brought about, the internal pressure of the brain will also have influenced the form of the skull; for

many facts shew how easily the skull is thus affected. Ethnologists believe that it is modified by the kind of

cradle in which infants sleep. Habitual spasms of the muscles, and a cicatrix from a severe burn, have

permanently modified the facial bones. In young persons whose heads have become fixed either sideways or

backwards, owing to disease, one of the two eyes has changed its position, and the shape of the skull has been

altered apparently by the pressure of the brain in a new direction. (84. Schaaffhausen gives from Blumenbach

and Busch, the cases of the spasms and cicatrix, in 'Anthropological Review,' Oct. 1868, p. 420. Dr. Jarrold

('Anthropologia,' 1808, pp. 115, 116) adduces from Camper and from his own observations, cases of the

modification of the skull from the head being fixed in an unnatural position. He believes that in certain trades,

such as that of a shoemaker, where the head is habitually held forward, the forehead becomes more rounded

and prominent.) I have shewn that with longeared rabbits even so trifling a cause as the lopping forward of

one ear drags forward almost every bone of the skull on that side; so that the bones on the opposite side no

longer strictly correspond. Lastly, if any animal were to increase or diminish much in general size, without

any change in its mental powers, or if the mental powers were to be much increased or diminished, without

any great change in the size of the body, the shape of the skull would almost certainly be altered. I infer this

from my observations on domestic rabbits, some kinds of which have become very much larger than the wild

animal, whilst others have retained nearly the same size, but in both cases the brain has been much reduced

relatively to the size of the body. Now I was at first much surprised on finding that in all these rabbits the

skull had become elongated or dolichocephalic; for instance, of two skulls of nearly equal breadth, the one

from a wild rabbit and the other from a large domestic kind, the former was 3.15 and the latter 4.3 inches in

length. (85. 'Variation of Animals and Plants under Domestication,' vol. i. p. 117, on the elongation of the

skull; p. 119, on the effect of the lopping of one ear.) One of the most marked distinctions in different races

of men is that the skull in some is elongated, and in others rounded; and here the explanation suggested by

the case of the rabbits may hold good; for Welcker finds that short "men incline more to brachycephaly, and

tall men to dolichocephaly" (86. Quoted by Schaaffhausen, in 'Anthropological Review,' Oct. 1868, p. 419.);

and tall men may be compared with the larger and longerbodied rabbits, all of which have elongated skulls

From these several facts we can understand, to a certain extent, the means by which the great size and more

or less rounded form of the skull have been acquired by man; and these are characters eminently distinctive

Another most conspicuous difference between man and the lower animals is the nakedness of his skin.

Whales and porpoises (Cetacea), dugongs (Sirenia) and the hippopotamus are naked; and this may be

advantageous to them for gliding through the water; nor would it be injurious to them from the loss of

warmth, as the species, which inhabit the colder regions, are protected by a thick layer of blubber, serving the

same purpose as the fur of seals and otters. Elephants and rhinoceroses are almost hairless; and as certain

extinct species, which formerly lived under an Arctic climate, were covered with long wool or hair, it would

almost appear as if the existing species of both genera had lost their hairy covering from exposure to heat.

This appears the more probable, as the elephants in India which live on elevated and cool districts are more

hairy (87. Owen, 'Anatomy of Vertebrates,' vol. iii. p. 619.) than those on the lowlands. May we then infer

that man became divested of hair from having aboriginally inhabited some tropical land? That the hair is

chiefly retained in the male sex on the chest and face, and in both sexes at the junction of all four limbs with

the trunk, favours this inferenceon the assumption that the hair was lost before man became erect; for the

parts which now retain most hair would then have been most protected from the heat of the sun. The crown of

the head, however, offers a curious exception, for at all times it must have been one of the most exposed

parts, yet it is thickly clothed with hair. The fact, however, that the other members of the order of Primates, to

which man belongs, although inhabiting various hot regions, are well clothed with hair, generally thickest on

the upper surface (88. Isidore Geoffroy St.Hilaire remarks ('Histoire Nat. Generale,' tom. ii. 1859, pp.

215217) on the head of man being covered with long hair; also on the upper surfaces of monkeys and of

other mammals being more thickly clothed than the lower surfaces. This has likewise been observed by

various authors. Prof. P. Gervais ('Histoire Nat. des Mammiferes,' tom. i. 1854, p. 28), however, states that in

the Gorilla the hair is thinner on the back, where it is partly rubbed off, than on the lower surface.), is

opposed to the supposition that man became naked through the action of the sun. Mr. Belt believes (89. The

'Naturalist in Nicaragua,' 1874, p. 209. As some confirmation of Mr. Belt's view, I may quote the following

passage from Sir W. Denison ('Varieties of ViceRegal Life,' vol. i. 1870, p. 440): "It is said to be a practice

with the Australians, when the vermin get troublesome, to singe themselves.") that within the tropics it is an

advantage to man to be destitute of hair, as he is thus enabled to free himself of the multitude of ticks (acari)

and other parasites, with which he is often infested, and which sometimes cause ulceration. But whether this

evil is of sufficient magnitude to have led to the denudation of his body through natural selection, may be

doubted, since none of the many quadrupeds inhabiting the tropics have, as far as I know, acquired any

specialised means of relief. The view which seems to me the most probable is that man, or rather primarily

woman, became divested of hair for ornamental purposes, as we shall see under Sexual Selection; and,

according to this belief, it is not surprising that man should differ so greatly in hairiness from all other

Primates, for characters, gained through sexual selection, often differ to an extraordinary degree in closely

According to a popular impression, the absence of a tail is eminently distinctive of man; but as those apes

which come nearest to him are destitute of this organ, its disappearance does not relate exclusively to man.

The tail often differs remarkably in length within the same genus: thus in some species of Macacus it is

longer than the whole body, and is formed of twentyfour vertebrae; in others it consists of a scarcely visible

stump, containing only three or four vertebrae. In some kinds of baboons there are twentyfive, whilst in the

mandrill there are ten very small stunted caudal vertebrae, or, according to Cuvier (90. Mr. St. George

Mivart, 'Proc. Zoolog. Soc.' 1865, pp. 562, 583. Dr. J.E. Gray, 'Cat. Brit. Mus.: 'Skeletons.' Owen, 'Anatomy

of Vertebrates,' vol. ii. p. 517. Isidore Geoffroy, 'Hist. Nat. Gen.' tom. ii. p. 244.), sometimes only five. The

tail, whether it be long or short, almost always tapers towards the end; and this, I presume, results from the

atrophy of the terminal muscles, together with their arteries and nerves, through disuse, leading to the atrophy

of the terminal bones. But no explanation can at present be given of the great diversity which often occurs in

its length. Here, however, we are more specially concerned with the complete external disappearance of the

tail. Professor Broca has recently shewn (91. 'Revue d'Anthropologie,' 1872; 'La Constitution des vertebres

caudales.') that the tail in all quadrupeds consists of two portions, generally separated abruptly from each

other; the basal portion consists of vertebrae, more or less perfectly channelled and furnished with apophyses

like ordinary vertebrae; whereas those of the terminal portion are not channelled, are almost smooth, and

scarcely resemble true vertebrae. A tail, though not externally visible, is really present in man and the

anthropomorphous apes, and is constructed on exactly the same pattern in both. In the terminal portion the

vertabrae, constituting the os coccyx, are quite rudimentary, being much reduced in size and number. In the

basal portion, the vertebrae are likewise few, are united firmly together, and are arrested in development; but

they have been rendered much broader and flatter than the corresponding vertebrae in the tails of other

animals: they constitute what Broca calls the accessory sacral vertebrae. These are of functional importance

by supporting certain internal parts and in other ways; and their modification is directly connected with the

erect or semierect attitude of man and the anthropomorphous apes. This conclusion is the more trustworthy,

as Broca formerly held a different view, which he has now abandoned. The modification, therefore, of the

basal caudal vertebrae in man and the higher apes may have been effected, directly or indirectly, through

But what are we to say about the rudimentary and variable vertebrae of the terminal portion of the tail,

forming the os coccyx? A notion which has often been, and will no doubt again be ridiculed, namely, that

friction has had something to do with the disappearance of the external portion of the tail, is not so ridiculous

as it at first appears. Dr. Anderson (92. 'Proceedings Zoological Society,' 1872, p. 210.) states that the

extremely short tail of Macacus brunneus is formed of eleven vertebrae, including the imbedded basal ones.

The extremity is tendinous and contains no vertebrae; this is succeeded by five rudimentary ones, so minute

that together they are only one line and a half in length, and these are permanently bent to one side in the

shape of a hook. The free part of the tail, only a little above an inch in length, includes only four more small

vertebrae. This short tail is carried erect; but about a quarter of its total length is doubled on to itself to the

left; and this terminal part, which includes the hooklike portion, serves "to fill up the interspace between the

upper divergent portion of the callosities;" so that the animal sits on it, and thus renders it rough and callous.

Dr. Anderson thus sums up his observations: "These facts seem to me to have only one explanation; this tail,

from its short size, is in the monkey's way when it sits down, and frequently becomes placed under the animal

while it is in this attitude; and from the circumstance that it does not extend beyond the extremity of the

ischial tuberosities, it seems as if the tail originally had been bent round by the will of the animal, into the

interspace between the callosities, to escape being pressed between them and the ground, and that in time the

curvature became permanent, fitting in of itself when the organ happens to be sat upon." Under these

circumstances it is not surprising that the surface of the tail should have been roughened and rendered

callous, and Dr. Murie (93. 'Proceedings Zoological Society,' 1872, p. 786.), who carefully observed this

species in the Zoological Gardens, as well as three other closely allied forms with slightly longer tails, says

that when the animal sits down, the tail "is necessarily thrust to one side of the buttocks; and whether long or

short its root is consequently liable to be rubbed or chafed." As we now have evidence that mutilations

occasionally produce an inherited effect (94. I allude to Dr. Brown Sequard's observations on the

transmitted effect of an operation causing epilepsy in guineapigs, and likewise more recently on the

analogous effects of cutting the sympathetic nerve in the neck. I shall hereafter have occasion to refer to Mr.

Salvin's interesting case of the apparently inherited effects of motmots biting off the barbs of their own tail

feathers. See also on the general subject 'Variation of Animals and Plants under Domestication,' vol. ii. pp.

2224.), it is not very improbable that in shorttailed monkeys, the projecting part of the tail, being

functionally useless, should after many generations have become rudimentary and distorted, from being

continually rubbed and chafed. We see the projecting part in this condition in the Macacus brunneus, and

absolutely aborted in the M. ecaudatus and in several of the higher apes. Finally, then, as far as we can judge,

the tail has disappeared in man and the anthropomorphous apes, owing to the terminal portion having been

injured by friction during a long lapse of time; the basal and embedded portion having been reduced and

I have now endeavoured to shew that some of the most distinctive characters of man have in all probability

been acquired, either directly, or more commonly indirectly, through natural selection. We should bear in

mind that modifications in structure or constitution which do not serve to adapt an organism to its habits of

life, to the food which it consumes, or passively to the surrounding conditions, cannot have been thus

acquired. We must not, however, be too confident in deciding what modifications are of service to each

being: we should remember how little we know about the use of many parts, or what changes in the blood or

tissues may serve to fit an organism for a new climate or new kinds of food. Nor must we forget the principle

of correlation, by which, as Isidore Geoffroy has shewn in the case of man, many strange deviations of

structure are tied together. Independently of correlation, a change in one part often leads, through the

increased or decreased use of other parts, to other changes of a quite unexpected nature. It is also well to

reflect on such facts, as the wonderful growth of galls on plants caused by the poison of an insect, and on the

remarkable changes of colour in the plumage of parrots when fed on certain fishes, or inoculated with the

poison of toads (95. The 'Variation of Animals and Plants under Domestication,' vol. ii. pp. 280, 282.); for we

can thus see that the fluids of the system, if altered for some special purpose, might induce other changes. We

should especially bear in mind that modifications acquired and continually used during past ages for some

useful purpose, would probably become firmly fixed, and might be long inherited.

Thus a large yet undefined extension may safely be given to the direct and indirect results of natural

selection; but I now admit, after reading the essay by Nageli on plants, and the remarks by various authors

with respect to animals, more especially those recently made by Professor Broca, that in the earlier editions of

my 'Origin of Species' I perhaps attributed too much to the action of natural selection or the survival of the

fittest. I have altered the fifth edition of the 'Origin' so as to confine my remarks to adaptive changes of

structure; but I am convinced, from the light gained during even the last few years, that very many structures

which now appear to us useless, will hereafter be proved to be useful, and will therefore come within the

range of natural selection. Nevertheless, I did not formerly consider sufficiently the existence of structures,

which, as far as we can at present judge, are neither beneficial nor injurious; and this I believe to be one of

the greatest oversights as yet detected in my work. I may be permitted to say, as some excuse, that I had two

distinct objects in view; firstly, to shew that species had not been separately created, and secondly, that

natural selection had been the chief agent of change, though largely aided by the inherited effects of habit,

and slightly by the direct action of the surrounding conditions. I was not, however, able to annul the influence

of my former belief, then almost universal, that each species had been purposely created; and this led to my

tacit assumption that every detail of structure, excepting rudiments, was of some special, though

unrecognised, service. Any one with this assumption in his mind would naturally extend too far the action of

natural selection, either during past or present times. Some of those who admit the principle of evolution, but

reject natural selection, seem to forget, when criticising my book, that I had the above two objects in view;

hence if I have erred in giving to natural selection great power, which I am very far from admitting, or in

having exaggerated its power, which is in itself probable, I have at least, as I hope, done good service in

It is, as I can now see, probable that all organic beings, including man, possess peculiarities of structure,

which neither are now, nor were formerly of any service to them, and which, therefore, are of no

physiological importance. We know not what produces the numberless slight differences between the

individuals of each species, for reversion only carries the problem a few steps backwards, but each peculiarity

must have had its efficient cause. If these causes, whatever they may be, were to act more uniformly and

energetically during a lengthened period (and against this no reason can be assigned), the result would

probably be not a mere slight individual difference, but a wellmarked and constant modification, though one

of no physiological importance. Changed structures, which are in no way beneficial, cannot be kept uniform

through natural selection, though the injurious will be thus eliminated. Uniformity of character would,

however, naturally follow from the assumed uniformity of the exciting causes, and likewise from the free

intercrossing of many individuals. During successive periods, the same organism might in this manner

acquire successive modifications, which would be transmitted in a nearly uniform state as long as the exciting

causes remained the same and there was free intercrossing. With respect to the exciting causes we can only

say, as when speaking of socalled spontaneous variations, that they relate much more closely to the

constitution of the varying organism, than to the nature of the conditions to which it has been subjected.

In this chapter we have seen that as man at the present day is liable, like every other animal, to multiform

individual differences or slight variations, so no doubt were the early progenitors of man; the variations being

formerly induced by the same general causes, and governed by the same general and complex laws as at

present. As all animals tend to multiply beyond their means of subsistence, so it must have been with the

progenitors of man; and this would inevitably lead to a struggle for existence and to natural selection. The

latter process would be greatly aided by the inherited effects of the increased use of parts, and these two

processes would incessantly react on each other. It appears, also, as we shall hereafter see, that various

unimportant characters have been acquired by man through sexual selection. An unexplained residuum of

change must be left to the assumed uniform action of those unknown agencies, which occasionally induce

Judging from the habits of savages and of the greater number of the Quadrumana, primeval men, and even

their apelike progenitors, probably lived in society. With strictly social animals, natural selection sometimes

acts on the individual, through the preservation of variations which are beneficial to the community. A

community which includes a large number of wellendowed individuals increases in number, and is

victorious over other less favoured ones; even although each separate member gains no advantage over the

others of the same community. Associated insects have thus acquired many remarkable structures, which are

of little or no service to the individual, such as the pollencollecting apparatus, or the sting of the

workerbee, or the great jaws of soldierants. With the higher social animals, I am not aware that any

structure has been modified solely for the good of the community, though some are of secondary service to it.

For instance, the horns of ruminants and the great canine teeth of baboons appear to have been acquired by

the males as weapons for sexual strife, but they are used in defence of the herd or troop. In regard to certain

mental powers the case, as we shall see in the fifth chapter, is wholly different; for these faculties have been

chiefly, or even exclusively, gained for the benefit of the community, and the individuals thereof have at the

It has often been objected to such views as the foregoing, that man is one of the most helpless and defenceless

creatures in the world; and that during his early and less welldeveloped condition, he would have been still

more helpless. The Duke of Argyll, for instance, insists (96. 'Primeval Man,' 1869, p. 66.) that "the human

frame has diverged from the structure of brutes, in the direction of greater physical helplessness and

weakness. That is to say, it is a divergence which of all others it is most impossible to ascribe to mere natural

selection." He adduces the naked and unprotected state of the body, the absence of great teeth or claws for

defence, the small strength and speed of man, and his slight power of discovering food or of avoiding danger

by smell. To these deficiencies there might be added one still more serious, namely, that he cannot climb

quickly, and so escape from enemies. The loss of hair would not have been a great injury to the inhabitants of

a warm country. For we know that the unclothed Fuegians can exist under a wretched climate. When we

compare the defenceless state of man with that of apes, we must remember that the great canine teeth with

which the latter are provided, are possessed in their full development by the males alone, and are chiefly used

by them for fighting with their rivals; yet the females, which are not thus provided, manage to survive.

In regard to bodily size or strength, we do not know whether man is descended from some small species, like

the chimpanzee, or from one as powerful as the gorilla; and, therefore, we cannot say whether man has

become larger and stronger, or smaller and weaker, than his ancestors. We should, however, bear in mind that

an animal possessing great size, strength, and ferocity, and which, like the gorilla, could defend itself from all

enemies, would not perhaps have become social: and this would most effectually have checked the

acquirement of the higher mental qualities, such as sympathy and the love of his fellows. Hence it might have

been an immense advantage to man to have sprung from some comparatively weak creature.

The small strength and speed of man, his want of natural weapons, etc., are more than counterbalanced,

firstly, by his intellectual powers, through which he has formed for himself weapons, tools, etc., though still

remaining in a barbarous state, and, secondly, by his social qualities which lead him to give and receive aid

from his fellowmen. No country in the world abounds in a greater degree with dangerous beasts than

Southern Africa; no country presents more fearful physical hardships than the Arctic regions; yet one of the

puniest of races, that of the Bushmen, maintains itself in Southern Africa, as do the dwarfed Esquimaux in the

Arctic regions. The ancestors of man were, no doubt, inferior in intellect, and probably in social disposition,

to the lowest existing savages; but it is quite conceivable that they might have existed, or even flourished, if

they had advanced in intellect, whilst gradually losing their brutelike powers, such as that of climbing trees,

etc. But these ancestors would not have been exposed to any special danger, even if far more helpless and

defenceless than any existing savages, had they inhabited some warm continent or large island, such as

Australia, New Guinea, or Borneo, which is now the home of the orang. And natural selection arising from

the competition of tribe with tribe, in some such large area as one of these, together with the inherited effects

of habit, would, under favourable conditions, have sufficed to raise man to his present high position in the

The difference in mental power between the highest ape and the lowest savage, immenseCertain instincts

ImitationAttentionMemoryImaginationReasonProgressive improvement Tools and weapons

used by animalsAbstraction, Selfconsciousness LanguageSense of beautyBelief in God, spiritual

We have seen in the last two chapters that man bears in his bodily structure clear traces of his descent from

some lower form; but it may be urged that, as man differs so greatly in his mental power from all other

animals, there must be some error in this conclusion. No doubt the difference in this respect is enormous,

even if we compare the mind of one of the lowest savages, who has no words to express any number higher

than four, and who uses hardly any abstract terms for common objects or for the affections (1. See the

evidence on those points, as given by Lubbock, 'Prehistoric Times,' p. 354, etc.), with that of the most highly

organised ape. The difference would, no doubt, still remain immense, even if one of the higher apes had been

improved or civilised as much as a dog has been in comparison with its parentform, the wolf or jackal. The

Fuegians rank amongst the lowest barbarians; but I was continually struck with surprise how closely the three

natives on board H.M.S. "Beagle," who had lived some years in England, and could talk a little English,

resembled us in disposition and in most of our mental faculties. If no organic being excepting man had

possessed any mental power, or if his powers had been of a wholly different nature from those of the lower

animals, then we should never have been able to convince ourselves that our high faculties had been

gradually developed. But it can be shewn that there is no fundamental difference of this kind. We must also

admit that there is a much wider interval in mental power between one of the lowest fishes, as a lamprey or

lancelet, and one of the higher apes, than between an ape and man; yet this interval is filled up by numberless

Nor is the difference slight in moral disposition between a barbarian, such as the man described by the old

navigator Byron, who dashed his child on the rocks for dropping a basket of seaurchins, and a Howard or

Clarkson; and in intellect, between a savage who uses hardly any abstract terms, and a Newton or

Shakspeare. Differences of this kind between the highest men of the highest races and the lowest savages, are

connected by the finest gradations. Therefore it is possible that they might pass and be developed into each

My object in this chapter is to shew that there is no fundamental difference between man and the higher

mammals in their mental faculties. Each division of the subject might have been extended into a separate

essay, but must here be treated briefly. As no classification of the mental powers has been universally

accepted, I shall arrange my remarks in the order most convenient for my purpose; and will select those facts

which have struck me most, with the hope that they may produce some effect on the reader.

With respect to animals very low in the scale, I shall give some additional facts under Sexual Selection,

shewing that their mental powers are much higher than might have been expected. The variability of the

faculties in the individuals of the same species is an important point for us, and some few illustrations will

here be given. But it would be superfluous to enter into many details on this head, for I have found on

frequent enquiry, that it is the unanimous opinion of all those who have long attended to animals of many

kinds, including birds, that the individuals differ greatly in every mental characteristic. In what manner the

mental powers were first developed in the lowest organisms, is as hopeless an enquiry as how life itself first

originated. These are problems for the distant future, if they are ever to be solved by man.

As man possesses the same senses as the lower animals, his fundamental intuitions must be the same. Man

has also some few instincts in common, as that of selfpreservation, sexual love, the love of the mother for

her new born offspring, the desire possessed by the latter to suck, and so forth. But man, perhaps, has

somewhat fewer instincts than those possessed by the animals which come next to him in the series. The

orang in the Eastern islands, and the chimpanzee in Africa, build platforms on which they sleep; and, as both

species follow the same habit, it might be argued that this was due to instinct, but we cannot feel sure that it is

not the result of both animals having similar wants, and possessing similar powers of reasoning. These apes,

as we may assume, avoid the many poisonous fruits of the tropics, and man has no such knowledge: but as

our domestic animals, when taken to foreign lands, and when first turned out in the spring, often eat

poisonous herbs, which they afterwards avoid, we cannot feel sure that the apes do not learn from their own

experience or from that of their parents what fruits to select. It is, however, certain, as we shall presently see,

that apes have an instinctive dread of serpents, and probably of other dangerous animals.

The fewness and the comparative simplicity of the instincts in the higher animals are remarkable in contrast

with those of the lower animals. Cuvier maintained that instinct and intelligence stand in an inverse ratio to

each other; and some have thought that the intellectual faculties of the higher animals have been gradually

developed from their instincts. But Pouchet, in an interesting essay (2. 'L'Instinct chez les Insectes,' 'Revue

des Deux Mondes,' Feb. 1870, p. 690.), has shewn that no such inverse ratio really exists. Those insects

which possess the most wonderful instincts are certainly the most intelligent. In the vertebrate series, the least

intelligent members, namely fishes and amphibians, do not possess complex instincts; and amongst mammals

the animal most remarkable for its instincts, namely the beaver, is highly intelligent, as will be admitted by

every one who has read Mr. Morgan's excellent work. (3. 'The American Beaver and His Works,' 1868.)

Although the first dawnings of intelligence, according to Mr. Herbert Spencer (4. 'The Principles of

Psychology,' 2nd edit., 1870, pp. 418 443.), have been developed through the multiplication and

coordination of reflex actions, and although many of the simpler instincts graduate into reflex actions, and

can hardly be distinguished from them, as in the case of young animals sucking, yet the more complex

instincts seem to have originated independently of intelligence. I am, however, very far from wishing to deny

that instinctive actions may lose their fixed and untaught character, and be replaced by others performed by

the aid of the free will. On the other hand, some intelligent actions, after being performed during several

generations, become converted into instincts and are inherited, as when birds on oceanic islands learn to

avoid man. These actions may then be said to be degraded in character, for they are no longer performed

through reason or from experience. But the greater number of the more complex instincts appear to have been

gained in a wholly different manner, through the natural selection of variations of simpler instinctive actions.

Such variations appear to arise from the same unknown causes acting on the cerebral organisation, which

induce slight variations or individual differences in other parts of the body; and these variations, owing to our

ignorance, are often said to arise spontaneously. We can, I think, come to no other conclusion with respect to

the origin of the more complex instincts, when we reflect on the marvellous instincts of sterile worker ants

and bees, which leave no offspring to inherit the effects of experience and of modified habits.

Although, as we learn from the abovementioned insects and the beaver, a high degree of intelligence is

certainly compatible with complex instincts, and although actions, at first learnt voluntarily can soon through

habit be performed with the quickness and certainty of a reflex action, yet it is not improbable that there is a

certain amount of interference between the development of free intelligence and of instinct,which latter

implies some inherited modification of the brain. Little is known about the functions of the brain, but we can

perceive that as the intellectual powers become highly developed, the various parts of the brain must be

connected by very intricate channels of the freest intercommunication; and as a consequence each separate

part would perhaps tend to be less well fitted to answer to particular sensations or associations in a definite

and inheritedthat is instinctivemanner. There seems even to exist some relation between a low degree of

intelligence and a strong tendency to the formation of fixed, though not inherited habits; for as a sagacious

physician remarked to me, persons who are slightly imbecile tend to act in everything by routine or habit; and

I have thought this digression worth giving, because we may easily underrate the mental powers of the higher

animals, and especially of man, when we compare their actions founded on the memory of past events, on

foresight, reason, and imagination, with exactly similar actions instinctively performed by the lower animals;

in this latter case the capacity of performing such actions has been gained, step by step, through the

variability of the mental organs and natural selection, without any conscious intelligence on the part of the

animal during each successive generation. No doubt, as Mr. Wallace has argued (5. 'Contributions to the

Theory of Natural Selection,' 1870, p. 212.), much of the intelligent work done by man is due to imitation and

not to reason; but there is this great difference between his actions and many of those performed by the lower

animals, namely, that man cannot, on his first trial, make, for instance, a stone hatchet or a canoe, through his

power of imitation. He has to learn his work by practice; a beaver, on the other hand, can make its dam or

canal, and a bird its nest, as well, or nearly as well, and a spider its wonderful web, quite as well (6. For the

evidence on this head, see Mr. J. Traherne Moggridge's most interesting work, 'Harvesting Ants and

TrapDoor Spiders,' 1873, pp. 126, 128.), the first time it tries as when old and experienced.

To return to our immediate subject: the lower animals, like man, manifestly feel pleasure and pain, happiness

and misery. Happiness is never better exhibited than by young animals, such as puppies, kittens, lambs, etc.,

when playing together, like our own children. Even insects play together, as has been described by that

excellent observer, P. Huber (7. 'Recherches sur les Moeurs des Fourmis,' 1810, p. 173.), who saw ants

The fact that the lower animals are excited by the same emotions as ourselves is so well established, that it

will not be necessary to weary the reader by many details. Terror acts in the same manner on them as on us,

causing the muscles to tremble, the heart to palpitate, the sphincters to be relaxed, and the hair to stand on

end. Suspicion, the offspring of fear, is eminently characteristic of most wild animals. It is, I think,

impossible to read the account given by Sir E. Tennent, of the behaviour of the female elephants, used as

decoys, without admitting that they intentionally practise deceit, and well know what they are about. Courage

and timidity are extremely variable qualities in the individuals of the same species, as is plainly seen in our

dogs. Some dogs and horses are illtempered, and easily turn sulky; others are goodtempered; and these

qualities are certainly inherited. Every one knows how liable animals are to furious rage, and how plainly

they shew it. Many, and probably true, anecdotes have been published on the longdelayed and artful

revenge of various animals. The accurate Rengger, and Brehm (8. All the following statements, given on the

authority of these two naturalists, are taken from Rengger's 'Naturgesch. der Saugethiere von Paraguay,'

1830, s. 4157, and from Brehm's 'Thierleben,' B. i. s. 1087.) state that the American and African monkeys

which they kept tame, certainly revenged themselves. Sir Andrew Smith, a zoologist whose scrupulous

accuracy was known to many persons, told me the following story of which he was himself an eye witness;

at the Cape of Good Hope an officer had often plagued a certain baboon, and the animal, seeing him

approaching one Sunday for parade, poured water into a hole and hastily made some thick mud, which he

skilfully dashed over the officer as he passed by, to the amusement of many bystanders. For long afterwards

The love of a dog for his master is notorious; as an old writer quaintly says (9. Quoted by Dr. Lauder

Lindsay, in his 'Physiology of Mind in the Lower Animals,' 'Journal of Mental Science,' April 1871, p. 38.),

"A dog is the only thing on this earth that luvs you more than he luvs himself."

In the agony of death a dog has been known to caress his master, and every one has heard of the dog suffering

under vivisection, who licked the hand of the operator; this man, unless the operation was fully justified by an

increase of our knowledge, or unless he had a heart of stone, must have felt remorse to the last hour of his

As Whewell (10. 'Bridgewater Treatise,' p. 263.) has well asked, "who that reads the touching instances of

maternal affection, related so often of the women of all nations, and of the females of all animals, can doubt

that the principle of action is the same in the two cases?" We see maternal affection exhibited in the most

trifling details; thus Rengger observed an American monkey (a Cebus) carefully driving away the flies which

plagued her infant; and Duvaucel saw a Hylobates washing the faces of her young ones in a stream. So

intense is the grief of female monkeys for the loss of their young, that it invariably caused the death of certain

kinds kept under confinement by Brehm in N. Africa. Orphan monkeys were always adopted and carefully

guarded by the other monkeys, both males and females. One female baboon had so capacious a heart that she

not only adopted young monkeys of other species, but stole young dogs and cats, which she continually

carried about. Her kindness, however, did not go so far as to share her food with her adopted offspring, at

which Brehm was surprised, as his monkeys always divided everything quite fairly with their own young

ones. An adopted kitten scratched this affectionate baboon, who certainly had a fine intellect, for she was

much astonished at being scratched, and immediately examined the kitten's feet, and without more ado bit off

the claws. (11. A critic, without any grounds ('Quarterly Review,' July 1871, p. 72), disputes the possibility of

this act as described by Brehm, for the sake of discrediting my work. Therefore I tried, and found that I could

readily seize with my own teeth the sharp little claws of a kitten nearly five weeks old.) In the Zoological

Gardens, I heard from the keeper that an old baboon (C. chacma) had adopted a Rhesus monkey; but when a

young drill and mandrill were placed in the cage, she seemed to perceive that these monkeys, though distinct

species, were her nearer relatives, for she at once rejected the Rhesus and adopted both of them. The young

Rhesus, as I saw, was greatly discontented at being thus rejected, and it would, like a naughty child, annoy

and attack the young drill and mandrill whenever it could do so with safety; this conduct exciting great

indignation in the old baboon. Monkeys will also, according to Brehm, defend their master when attacked by

any one, as well as dogs to whom they are attached, from the attacks of other dogs. But we here trench on the

subjects of sympathy and fidelity, to which I shall recur. Some of Brehm's monkeys took much delight in

teasing a certain old dog whom they disliked, as well as other animals, in various ingenious ways.

Most of the more complex emotions are common to the higher animals and ourselves. Every one has seen

how jealous a dog is of his master's affection, if lavished on any other creature; and I have observed the same

fact with monkeys. This shews that animals not only love, but have desire to be loved. Animals manifestly

feel emulation. They love approbation or praise; and a dog carrying a basket for his master exhibits in a high

degree selfcomplacency or pride. There can, I think, be no doubt that a dog feels shame, as distinct from

fear, and something very like modesty when begging too often for food. A great dog scorns the snarling of a

little dog, and this may be called magnanimity. Several observers have stated that monkeys certainly dislike

being laughed at; and they sometimes invent imaginary offences. In the Zoological Gardens I saw a baboon

who always got into a furious rage when his keeper took out a letter or book and read it aloud to him; and his

rage was so violent that, as I witnessed on one occasion, he bit his own leg till the blood flowed. Dogs shew

what may be fairly called a sense of humour, as distinct from mere play; if a bit of stick or other such object

be thrown to one, he will often carry it away for a short distance; and then squatting down with it on the

ground close before him, will wait until his master comes quite close to take it away. The dog will then seize

it and rush away in triumph, repeating the same manoeuvre, and evidently enjoying the practical joke.

We will now turn to the more intellectual emotions and faculties, which are very important, as forming the

basis for the development of the higher mental powers. Animals manifestly enjoy excitement, and suffer from

ennui, as may be seen with dogs, and, according to Rengger, with monkeys. All animals feel WONDER, and

many exhibit CURIOSITY. They sometimes suffer from this latter quality, as when the hunter plays antics

and thus attracts them; I have witnessed this with deer, and so it is with the wary chamois, and with some

kinds of wildducks. Brehm gives a curious account of the instinctive dread, which his monkeys exhibited,

for snakes; but their curiosity was so great that they could not desist from occasionally satiating their horror

in a most human fashion, by lifting up the lid of the box in which the snakes were kept. I was so much

surprised at his account, that I took a stuffed and coiledup snake into the monkeyhouse at the Zoological

Gardens, and the excitement thus caused was one of the most curious spectacles which I ever beheld. Three

species of Cercopithecus were the most alarmed; they dashed about their cages, and uttered sharp signal cries

of danger, which were understood by the other monkeys. A few young monkeys and one old Anubis baboon

alone took no notice of the snake. I then placed the stuffed specimen on the ground in one of the larger

compartments. After a time all the monkeys collected round it in a large circle, and staring intently, presented

a most ludicrous appearance. They became extremely nervous; so that when a wooden ball, with which they

were familiar as a plaything, was accidentally moved in the straw, under which it was partly hidden, they all

instantly started away. These monkeys behaved very differently when a dead fish, a mouse (12. I have given

a short account of their behaviour on this occasion in my 'Expression of the Emotions in Man and Animals,'

p. 43.), a living turtle, and other new objects were placed in their cages; for though at first frightened, they

soon approached, handled and examined them. I then placed a live snake in a paper bag, with the mouth

loosely closed, in one of the larger compartments. One of the monkeys immediately approached, cautiously

opened the bag a little, peeped in, and instantly dashed away. Then I witnessed what Brehm has described,

for monkey after monkey, with head raised high and turned on one side, could not resist taking a momentary

peep into the upright bag, at the dreadful object lying quietly at the bottom. It would almost appear as if

monkeys had some notion of zoological affinities, for those kept by Brehm exhibited a strange, though

mistaken, instinctive dread of innocent lizards and frogs. An orang, also, has been known to be much alarmed

at the first sight of a turtle. (13. W.C.L. Martin, 'Natural History of Mammalia,' 1841, p. 405.)

The principle of IMITATION is strong in man, and especially, as I have myself observed, with savages. In

certain morbid states of the brain this tendency is exaggerated to an extraordinary degree: some hemiplegic

patients and others, at the commencement of inflammatory softening of the brain, unconsciously imitate

every word which is uttered, whether in their own or in a foreign language, and every gesture or action which

is performed near them. (14. Dr. Bateman, 'On Aphasia,' 1870, p. 110.) Desor (15. Quoted by Vogt, 'Memoire

sur les Microcephales,' 1867, p. 168.) has remarked that no animal voluntarily imitates an action performed

by man, until in the ascending scale we come to monkeys, which are well known to be ridiculous mockers.

Animals, however, sometimes imitate each other's actions: thus two species of wolves, which had been reared

by dogs, learned to bark, as does sometimes the jackal (16. The 'Variation of Animals and Plants under

Domestication,' vol. i. p. 27.), but whether this can be called voluntary imitation is another question. Birds

imitate the songs of their parents, and sometimes of other birds; and parrots are notorious imitators of any

sound which they often hear. Dureau de la Malle gives an account (17. 'Annales des Sciences Nat.' (1st

Series), tom. xxii. p. 397.) of a dog reared by a cat, who learnt to imitate the wellknown action of a cat

licking her paws, and thus washing her ears and face; this was also witnessed by the celebrated naturalist

Audouin. I have received several confirmatory accounts; in one of these, a dog had not been suckled by a cat,

but had been brought up with one, together with kittens, and had thus acquired the above habit, which he ever

afterwards practised during his life of thirteen years. Dureau de la Malle's dog likewise learnt from the kittens

to play with a ball by rolling it about with his fore paws, and springing on it. A correspondent assures me that

a cat in his house used to put her paws into jugs of milk having too narrow a mouth for her head. A kitten of

this cat soon learned the same trick, and practised it ever afterwards, whenever there was an opportunity.

The parents of many animals, trusting to the principle of imitation in their young, and more especially to their

instinctive or inherited tendencies, may be said to educate them. We see this when a cat brings a live mouse

to her kittens; and Dureau de la Malle has given a curious account (in the paper above quoted) of his

observations on hawks which taught their young dexterity, as well as judgment of distances, by first dropping

through the air dead mice and sparrows, which the young generally failed to catch, and then bringing them

Hardly any faculty is more important for the intellectual progress of man than ATTENTION. Animals clearly

manifest this power, as when a cat watches by a hole and prepares to spring on its prey. Wild animals

sometimes become so absorbed when thus engaged, that they may be easily approached. Mr. Bartlett has

given me a curious proof how variable this faculty is in monkeys. A man who trains monkeys to act in plays,

used to purchase common kinds from the Zoological Society at the price of five pounds for each; but he

offered to give double the price, if he might keep three or four of them for a few days, in order to select one.

When asked how he could possibly learn so soon, whether a particular monkey would turn out a good actor,

he answered that it all depended on their power of attention. If when he was talking and explaining anything

to a monkey, its attention was easily distracted, as by a fly on the wall or other trifling object, the case was

hopeless. If he tried by punishment to make an inattentive monkey act, it turned sulky. On the other hand, a

It is almost superfluous to state that animals have excellent MEMORIES for persons and places. A baboon at

the Cape of Good Hope, as I have been informed by Sir Andrew Smith, recognised him with joy after an

absence of nine months. I had a dog who was savage and averse to all strangers, and I purposely tried his

memory after an absence of five years and two days. I went near the stable where he lived, and shouted to

him in my old manner; he shewed no joy, but instantly followed me out walking, and obeyed me, exactly as

if I had parted with him only half an hour before. A train of old associations, dormant during five years, had

thus been instantaneously awakened in his mind. Even ants, as P. Huber (18. 'Les Moeurs des Fourmis,' 1810,

p. 150.) has clearly shewn, recognised their fellowants belonging to the same community after a separation

of four months. Animals can certainly by some means judge of the intervals of time between recurrent events.

The IMAGINATION is one of the highest prerogatives of man. By this faculty he unites former images and

ideas, independently of the will, and thus creates brilliant and novel results. A poet, as Jean Paul Richter

remarks (19. Quoted in Dr. Maudsley's 'Physiology and Pathology of Mind,' 1868, pp. 19, 220.), "who must

reflect whether he shall make a character say yes or noto the devil with him; he is only a stupid corpse."

Dreaming gives us the best notion of this power; as Jean Paul again says, "The dream is an involuntary art of

poetry." The value of the products of our imagination depends of course on the number, accuracy, and

clearness of our impressions, on our judgment and taste in selecting or rejecting the involuntary

combinations, and to a certain extent on our power of voluntarily combining them. As dogs, cats, horses, and

probably all the higher animals, even birds (20. Dr. Jerdon, 'Birds of India,' vol. i. 1862, p. xxi. Houzeau says

that his parokeets and canarybirds dreamt: 'Etudes sur les Facultes Mentales des Animaux,' tom. ii. p. 136.)

have vivid dreams, and this is shewn by their movements and the sounds uttered, we must admit that they

possess some power of imagination. There must be something special, which causes dogs to howl in the

night, and especially during moonlight, in that remarkable and melancholy manner called baying. All dogs do

not do so; and, according to Houzeau (21. ibid. 1872, tom. ii. p. 181.), they do not then look at the moon, but

at some fixed point near the horizon. Houzeau thinks that their imaginations are disturbed by the vague

outlines of the surrounding objects, and conjure up before them fantastic images: if this be so, their feelings

Of all the faculties of the human mind, it will, I presume, be admitted that REASON stands at the summit.

Only a few persons now dispute that animals possess some power of reasoning. Animals may constantly be

seen to pause, deliberate, and resolve. It is a significant fact, that the more the habits of any particular animal

are studied by a naturalist, the more he attributes to reason and the less to unlearnt instincts. (22. Mr. L.H.

Morgan's work on 'The American Beaver,' 1868, offers a good illustration of this remark. I cannot help

thinking, however, that he goes too far in underrating the power of instinct.) In future chapters we shall see

that some animals extremely low in the scale apparently display a certain amount of reason. No doubt it is

often difficult to distinguish between the power of reason and that of instinct. For instance, Dr. Hayes, in his

work on 'The Open Polar Sea,' repeatedly remarks that his dogs, instead of continuing to draw the sledges in a

compact body, diverged and separated when they came to thin ice, so that their weight might be more evenly

distributed. This was often the first warning which the travellers received that the ice was becoming thin and

dangerous. Now, did the dogs act thus from the experience of each individual, or from the example of the

older and wiser dogs, or from an inherited habit, that is from instinct? This instinct, may possibly have arisen

since the time, long ago, when dogs were first employed by the natives in drawing their sledges; or the Arctic

wolves, the parentstock of the Esquimaux dog, may have acquired an instinct impelling them not to attack

We can only judge by the circumstances under which actions are performed, whether they are due to instinct,

or to reason, or to the mere association of ideas: this latter principle, however, is intimately connected with

reason. A curious case has been given by Prof. Mobius (23. 'Die Bewegungen der Thiere,' etc., 1873, p. 11.),

of a pike, separated by a plate of glass from an adjoining aquarium stocked with fish, and who often dashed

himself with such violence against the glass in trying to catch the other fishes, that he was sometimes

completely stunned. The pike went on thus for three months, but at last learnt caution, and ceased to do so.

The plate of glass was then removed, but the pike would not attack these particular fishes, though he would

devour others which were afterwards introduced; so strongly was the idea of a violent shock associated in his

feeble mind with the attempt on his former neighbours. If a savage, who had never seen a large plateglass

window, were to dash himself even once against it, he would for a long time afterwards associate a shock

with a windowframe; but very differently from the pike, he would probably reflect on the nature of the

impediment, and be cautious under analogous circumstances. Now with monkeys, as we shall presently see, a

painful or merely a disagreeable impression, from an action once performed, is sometimes sufficient to

prevent the animal from repeating it. If we attribute this difference between the monkey and the pike solely to

the association of ideas being so much stronger and more persistent in the one than the other, though the pike

often received much the more severe injury, can we maintain in the case of man that a similar difference

Houzeau relates (24. 'Etudes sur les Facultes Mentales des Animaux,' 1872, tom. ii. p. 265.) that, whilst

crossing a wide and arid plain in Texas, his two dogs suffered greatly from thirst, and that between thirty and

forty times they rushed down the hollows to search for water. These hollows were not valleys, and there were

no trees in them, or any other difference in the vegetation, and as they were absolutely dry there could have

been no smell of damp earth. The dogs behaved as if they knew that a dip in the ground offered them the best

chance of finding water, and Houzeau has often witnessed the same behaviour in other animals.

I have seen, as I daresay have others, that when a small object is thrown on the ground beyond the reach of

one of the elephants in the Zoological Gardens, he blows through his trunk on the ground beyond the object,

so that the current reflected on all sides may drive the object within his reach. Again a wellknown

ethnologist, Mr. Westropp, informs me that he observed in Vienna a bear deliberately making with his paw a

current in some water, which was close to the bars of his cage, so as to draw a piece of floating bread within

his reach. These actions of the elephant and bear can hardly be attributed to instinct or inherited habit, as they

would be of little use to an animal in a state of nature. Now, what is the difference between such actions,

The savage and the dog have often found water at a low level, and the coincidence under such circumstances

has become associated in their minds. A cultivated man would perhaps make some general proposition on the

subject; but from all that we know of savages it is extremely doubtful whether they would do so, and a dog

certainly would not. But a savage, as well as a dog, would search in the same way, though frequently

disappointed; and in both it seems to be equally an act of reason, whether or not any general proposition on

the subject is consciously placed before the mind. (25. Prof. Huxley has analysed with admirable clearness

the mental steps by which a man, as well as a dog, arrives at a conclusion in a case analogous to that given in

my text. See his article, 'Mr. Darwin's Critics,' in the 'Contemporary Review,' Nov. 1871, p. 462, and in his

'Critiques and Essays,' 1873, p. 279.) The same would apply to the elephant and the bear making currents in

the air or water. The savage would certainly neither know nor care by what law the desired movements were

effected; yet his act would be guided by a rude process of reasoning, as surely as would a philosopher in his

longest chain of deductions. There would no doubt be this difference between him and one of the higher

animals, that he would take notice of much slighter circumstances and conditions, and would observe any

connection between them after much less experience, and this would be of paramount importance. I kept a

daily record of the actions of one of my infants, and when he was about eleven months old, and before he

could speak a single word, I was continually struck with the greater quickness, with which all sorts of objects

and sounds were associated together in his mind, compared with that of the most intelligent dogs I ever knew.

But the higher animals differ in exactly the same way in this power of association from those low in the scale,

The promptings of reason, after very short experience, are well shewn by the following actions of American

monkeys, which stand low in their order. Rengger, a most careful observer, states that when he first gave

eggs to his monkeys in Paraguay, they smashed them, and thus lost much of their contents; afterwards they

gently hit one end against some hard body, and picked off the bits of shell with their fingers. After cutting

themselves only ONCE with any sharp tool, they would not touch it again, or would handle it with the

greatest caution. Lumps of sugar were often given them wrapped up in paper; and Rengger sometimes put a

live wasp in the paper, so that in hastily unfolding it they got stung; after this had ONCE happened, they

always first held the packet to their ears to detect any movement within. (26. Mr. Belt, in his most interesting

work, 'The Naturalist in Nicaragua,' 1874, (p. 119,) likewise describes various actions of a tamed Cebus,

The following cases relate to dogs. Mr. Colquhoun (27. 'The Moor and the Loch,' p. 45. Col. Hutchinson on

'Dog Breaking,' 1850, p. 46.) winged two wildducks, which fell on the further side of a stream; his retriever

tried to bring over both at once, but could not succeed; she then, though never before known to ruffle a

feather, deliberately killed one, brought over the other, and returned for the dead bird. Col. Hutchinson relates

that two partridges were shot at once, one being killed, the other wounded; the latter ran away, and was

caught by the retriever, who on her return came across the dead bird; "she stopped, evidently greatly puzzled,

and after one or two trials, finding she could not take it up without permitting the escape of the winged bird,

she considered a moment, then deliberately murdered it by giving it a severe crunch, and afterwards brought

away both together. This was the only known instance of her ever having wilfully injured any game." Here

we have reason though not quite perfect, for the retriever might have brought the wounded bird first and then

returned for the dead one, as in the case of the two wildducks. I give the above cases, as resting on the

evidence of two independent witnesses, and because in both instances the retrievers, after deliberation, broke

through a habit which is inherited by them (that of not killing the game retrieved), and because they shew

I will conclude by quoting a remark by the illustrious Humboldt. (28. 'Personal Narrative,' Eng. translat., vol.

iii. p. 106.) "The muleteers in S. America say, 'I will not give you the mule whose step is easiest, but la mas

racional,the one that reasons best'"; and; as, he adds, "this popular expression, dictated by long experience,

combats the system of animated machines, better perhaps than all the arguments of speculative philosophy."

Nevertheless some writers even yet deny that the higher animals possess a trace of reason; and they

endeavour to explain away, by what appears to be mere verbiage, (29. I am glad to find that so acute a

reasoner as Mr. Leslie Stephen ('Darwinism and Divinity, Essays on Free Thinking,' 1873, p. 80), in speaking

of the supposed impassable barrier between the minds of man and the lower animals, says, "The distinctions,

indeed, which have been drawn, seem to us to rest upon no better foundation than a great many other

metaphysical distinctions; that is, the assumption that because you can give two things different names, they

must therefore have different natures. It is difficult to understand how anybody who has ever kept a dog, or

seen an elephant, can have any doubt as to an animal's power of performing the essential processes of

It has, I think, now been shewn that man and the higher animals, especially the Primates, have some few

instincts in common. All have the same senses, intuitions, and sensations,similar passions, affections, and

emotions, even the more complex ones, such as jealousy, suspicion, emulation, gratitude, and magnanimity;

they practise deceit and are revengeful; they are sometimes susceptible to ridicule, and even have a sense of

humour; they feel wonder and curiosity; they possess the same faculties of imitation, attention, deliberation,

choice, memory, imagination, the association of ideas, and reason, though in very different degrees. The

individuals of the same species graduate in intellect from absolute imbecility to high excellence. They are

also liable to insanity, though far less often than in the case of man. (30. See 'Madness in Animals,' by Dr. W.

Lauder Lindsay, in 'Journal of Mental Science,' July 1871.) Nevertheless, many authors have insisted that

man is divided by an insuperable barrier from all the lower animals in his mental faculties. I formerly made a

collection of above a score of such aphorisms, but they are almost worthless, as their wide difference and

number prove the difficulty, if not the impossibility, of the attempt. It has been asserted that man alone is

capable of progressive improvement; that he alone makes use of tools or fire, domesticates other animals, or

possesses property; that no animal has the power of abstraction, or of forming general concepts, is

selfconscious and comprehends itself; that no animal employs language; that man alone has a sense of

beauty, is liable to caprice, has the feeling of gratitude, mystery, etc.; believes in God, or is endowed with a

conscience. I will hazard a few remarks on the more important and interesting of these points.

Archbishop Sumner formerly maintained (31. Quoted by Sir C. Lyell, 'Antiquity of Man,' p. 497.) that man

alone is capable of progressive improvement. That he is capable of incomparably greater and more rapid

improvement than is any other animal, admits of no dispute; and this is mainly due to his power of speaking

and handing down his acquired knowledge. With animals, looking first to the individual, every one who has

had any experience in setting traps, knows that young animals can he caught much more easily than old ones;

and they can be much more easily approached by an enemy. Even with respect to old animals, it is impossible

to catch many in the same place and in the same kind of trap, or to destroy them by the same kind of poison;

yet it is improbable that all should have partaken of the poison, and impossible that all should have been

caught in a trap. They must learn caution by seeing their brethren caught or poisoned. In North America,

where the furbearing animals have long been pursued, they exhibit, according to the unanimous testimony

of all observers, an almost incredible amount of sagacity, caution and cunning; but trapping has been there so

long carried on, that inheritance may possibly have come into play. I have received several accounts that

when telegraphs are first set up in any district, many birds kill themselves by flying against the wires, but that

in the course of a very few years they learn to avoid this danger, by seeing, as it would appear, their comrades

killed. (32. For additional evidence, with details, see M. Houzeau, 'Etudes sur les Facultes Mentales des

If we look to successive generations, or to the race, there is no doubt that birds and other animals gradually

both acquire and lose caution in relation to man or other enemies (33. See, with respect to birds on oceanic

islands, my 'Journal of Researches during the Voyage of the "Beagle,"' 1845, p. 398. 'Origin of Species,' 5th

ed. p. 260.); and this caution is certainly in chief part an inherited habit or instinct, but in part the result of

individual experience. A good observer, Leroy (34. 'Lettres Phil. sur l'Intelligence des Animaux,' nouvelle

edit., 1802, p. 86.), states, that in districts where foxes are much hunted, the young, on first leaving their

burrows, are incontestably much more wary than the old ones in districts where they are not much disturbed.

Our domestic dogs are descended from wolves and jackals (35. See the evidence on this head in chap. i. vol.

i., 'On the Variation of Animals and Plants under Domestication.'), and though they may not have gained in

cunning, and may have lost in wariness and suspicion, yet they have progressed in certain moral qualities,

such as in affection, trust worthiness, temper, and probably in general intelligence. The common rat has

conquered and beaten several other species throughout Europe, in parts of North America, New Zealand, and

recently in Formosa, as well as on the mainland of China. Mr. Swinhoe (36. 'Proceedings Zoological Society,'

1864, p. 186.), who describes these two latter cases, attributes the victory of the common rat over the large

Mus coninga to its superior cunning; and this latter quality may probably be attributed to the habitual exercise

of all its faculties in avoiding extirpation by man, as well as to nearly all the less cunning or weakminded

rats having been continuously destroyed by him. It is, however, possible that the success of the common rat

may be due to its having possessed greater cunning than its fellow species, before it became associated with

man. To maintain, independently of any direct evidence, that no animal during the course of ages has

progressed in intellect or other mental faculties, is to beg the question of the evolution of species. We have

seen that, according to Lartet, existing mammals belonging to several orders have larger brains than their

It has often been said that no animal uses any tool; but the chimpanzee in a state of nature cracks a native

fruit, somewhat like a walnut, with a stone. (37. Savage and Wyman in 'Boston Journal of Natural History,'

vol. iv. 184344, p. 383.) Rengger (38. 'Saugethiere von Paraguay,' 1830, s. 5156.) easily taught an

American monkey thus to break open hard palmnuts; and afterwards of its own accord, it used stones to

open other kinds of nuts, as well as boxes. It thus also removed the soft rind of fruit that had a disagreeable

flavour. Another monkey was taught to open the lid of a large box with a stick, and afterwards it used the

stick as a lever to move heavy bodies; and I have myself seen a young orang put a stick into a crevice, slip his

hand to the other end, and use it in the proper manner as a lever. The tamed elephants in India are well known

to break off branches of trees and use them to drive away the flies; and this same act has been observed in an

elephant in a state of nature. (39. The Indian Field, March 4, 1871.) I have seen a young orang, when she

thought she was going to be whipped, cover and protect herself with a blanket or straw. In these several cases

stones and sticks were employed as implements; but they are likewise used as weapons. Brehm (40.

'Thierleben,' B. i. s. 79, 82.) states, on the authority of the wellknown traveller Schimper, that in Abyssinia

when the baboons belonging to one species (C. gelada) descend in troops from the mountains to plunder the

fields, they sometimes encounter troops of another species (C. hamadryas), and then a fight ensues. The

Geladas roll down great stones, which the Hamadryas try to avoid, and then both species, making a great

uproar, rush furiously against each other. Brehm, when accompanying the Duke of CoburgGotha, aided in

an attack with firearms on a troop of baboons in the pass of Mensa in Abyssinia. The baboons in return

rolled so many stones down the mountain, some as large as a man's head, that the attackers had to beat a

hasty retreat; and the pass was actually closed for a time against the caravan. It deserves notice that these

baboons thus acted in concert. Mr. Wallace (41. 'The Malay Archipelago,' vol. i. 1869, p. 87.) on three

occasions saw female orangs, accompanied by their young, "breaking off branches and the great spiny fruit of

the Durian tree, with every appearance of rage; causing such a shower of missiles as effectually kept us from

approaching too near the tree." As I have repeatedly seen, a chimpanzee will throw any object at hand at a

person who offends him; and the beforementioned baboon at the Cape of Good Hope prepared mud for the

In the Zoological Gardens, a monkey, which had weak teeth, used to break open nuts with a stone; and I was

assured by the keepers that after using the stone, he hid it in the straw, and would not let any other monkey

touch it. Here, then, we have the idea of property; but this idea is common to every dog with a bone, and to

The Duke of Argyll (42. 'Primeval Man,' 1869, pp. 145, 147.) remarks, that the fashioning of an implement

for a special purpose is absolutely peculiar to man; and he considers that this forms an immeasurable gulf

between him and the brutes. This is no doubt a very important distinction; but there appears to me much truth

in Sir J. Lubbock's suggestion (43. 'Prehistoric Times,' 1865, p. 473, etc.), that when primeval man first used

flintstones for any purpose, he would have accidentally splintered them, and would then have used the sharp

fragments. From this step it would be a small one to break the flints on purpose, and not a very wide step to

fashion them rudely. This latter advance, however, may have taken long ages, if we may judge by the

immense interval of time which elapsed before the men of the neolithic period took to grinding and polishing

their stone tools. In breaking the flints, as Sir J. Lubbock likewise remarks, sparks would have been emitted,

and in grinding them heat would have been evolved: thus the two usual methods of "obtaining fire may have

originated." The nature of fire would have been known in the many volcanic regions where lava occasionally

flows through forests. The anthropomorphous apes, guided probably by instinct, build for themselves

temporary platforms; but as many instincts are largely controlled by reason, the simpler ones, such as this of

building a platform, might readily pass into a voluntary and conscious act. The orang is known to cover itself

at night with the leaves of the Pandanus; and Brehm states that one of his baboons used to protect itself from

the heat of the sun by throwing a strawmat over its head. In these several habits, we probably see the first

steps towards some of the simpler arts, such as rude architecture and dress, as they arose amongst the early

It would be very difficult for any one with even much more knowledge than I possess, to determine how far

animals exhibit any traces of these high mental powers. This difficulty arises from the impossibility of

judging what passes through the mind of an animal; and again, the fact that writers differ to a great extent in

the meaning which they attribute to the above terms, causes a further difficulty. If one may judge from

various articles which have been published lately, the greatest stress seems to be laid on the supposed entire

absence in animals of the power of abstraction, or of forming general concepts. But when a dog sees another

dog at a distance, it is often clear that he perceives that it is a dog in the abstract; for when he gets nearer his

whole manner suddenly changes, if the other dog be a friend. A recent writer remarks, that in all such cases it

is a pure assumption to assert that the mental act is not essentially of the same nature in the animal as in man.

If either refers what he perceives with his senses to a mental concept, then so do both. (44. Mr. Hookham, in

a letter to Prof. Max Muller, in the 'Birmingham News,' May 1873.) When I say to my terrier, in an eager

voice (and I have made the trial many times), "Hi, hi, where is it?" she at once takes it as a sign that

something is to be hunted, and generally first looks quickly all around, and then rushes into the nearest

thicket, to scent for any game, but finding nothing, she looks up into any neighbouring tree for a squirrel.

Now do not these actions clearly shew that she had in her mind a general idea or concept that some animal is

It may be freely admitted that no animal is selfconscious, if by this term it is implied, that he reflects on

such points, as whence he comes or whither he will go, or what is life and death, and so forth. But how can

we feel sure that an old dog with an excellent memory and some power of imagination, as shewn by his

dreams, never reflects on his past pleasures or pains in the chase? And this would be a form of

selfconsciousness. On the other hand, as Buchner (45. 'Conferences sur la Theorie Darwinienne,' French

translat. 1869, p. 132.) has remarked, how little can the hard worked wife of a degraded Australian savage,

who uses very few abstract words, and cannot count above four, exert her selfconsciousness, or reflect on

the nature of her own existence. It is generally admitted, that the higher animals possess memory, attention,

association, and even some imagination and reason. If these powers, which differ much in different animals,

are capable of improvement, there seems no great improbability in more complex faculties, such as the higher

forms of abstraction, and self consciousness, etc., having been evolved through the development and

combination of the simpler ones. It has been urged against the views here maintained that it is impossible to

say at what point in the ascending scale animals become capable of abstraction, etc.; but who can say at what

age this occurs in our young children? We see at least that such powers are developed in children by

That animals retain their mental individuality is unquestionable. When my voice awakened a train of old

associations in the mind of the before mentioned dog, he must have retained his mental individuality,

although every atom of his brain had probably undergone change more than once during the interval of five

years. This dog might have brought forward the argument lately advanced to crush all evolutionists, and said,

"I abide amid all mental moods and all material changes...The teaching that atoms leave their impressions as

legacies to other atoms falling into the places they have vacated is contradictory of the utterance of

consciousness, and is therefore false; but it is the teaching necessitated by evolutionism, consequently the

hypothesis is a false one." (46. The Rev. Dr. J. M'Cann, 'AntiDarwinism,' 1869, p. 13.)

This faculty has justly been considered as one of the chief distinctions between man and the lower animals.

But man, as a highly competent judge, Archbishop Whately remarks, "is not the only animal that can make

use of language to express what is passing in his mind, and can understand, more or less, what is so expressed

by another." (47. Quoted in 'Anthropological Review,' 1864, p. 158.) In Paraguay the Cebus azarae when

excited utters at least six distinct sounds, which excite in other monkeys similar emotions. (48. Rengger, ibid.

s. 45.) The movements of the features and gestures of monkeys are understood by us, and they partly

understand ours, as Rengger and others declare. It is a more remarkable fact that the dog, since being

domesticated, has learnt to bark (49. See my 'Variation of Animals and Plants under Domestication,' vol. i. p.

27.) in at least four or five distinct tones. Although barking is a new art, no doubt the wild parentspecies of

the dog expressed their feelings by cries of various kinds. With the domesticated dog we have the bark of

eagerness, as in the chase; that of anger, as well as growling; the yelp or howl of despair, as when shut up; the

baying at night; the bark of joy, as when starting on a walk with his master; and the very distinct one of

demand or supplication, as when wishing for a door or window to be opened. According to Houzeau, who

paid particular attention to the subject, the domestic fowl utters at least a dozen significant sounds. (50.

The habitual use of articulate language is, however, peculiar to man; but he uses, in common with the lower

animals, inarticulate cries to express his meaning, aided by gestures and the movements of the muscles of the

face. (51. See a discussion on this subject in Mr. E.B. Tylor's very interesting work, 'Researches into the

Early History of Mankind,' 1865, chaps. ii. to iv.) This especially holds good with the more simple and vivid

feelings, which are but little connected with our higher intelligence. Our cries of pain, fear, surprise, anger,

together with their appropriate actions, and the murmur of a mother to her beloved child are more expressive

than any words. That which distinguishes man from the lower animals is not the understanding of articulate

sounds, for, as every one knows, dogs understand many words and sentences. In this respect they are at the

same stage of development as infants, between the ages of ten and twelve months, who understand many

words and short sentences, but cannot yet utter a single word. It is not the mere articulation which is our

distinguishing character, for parrots and other birds possess this power. Nor is it the mere capacity of

connecting definite sounds with definite ideas; for it is certain that some parrots, which have been taught to

speak, connect unerringly words with things, and persons with events. (52. I have received several detailed

accounts to this effect. Admiral Sir B.J. Sulivan, whom I know to be a careful observer, assures me that an

African parrot, long kept in his father's house, invariably called certain persons of the household, as well as

visitors, by their names. He said "good morning" to every one at breakfast, and "good night" to each as they

left the room at night, and never reversed these salutations. To Sir B.J. Sulivan's father, he used to add to the

" good morning" a short sentence, which was never once repeated after his father's death. He scolded

violently a strange dog which came into the room through the open window; and he scolded another parrot

(saying "you naughty polly") which had got out of its cage, and was eating apples on the kitchen table. See

also, to the same effect, Houzeau on parrots, 'Facultes Mentales,' tom. ii. p. 309. Dr. A. Moschkau informs me

that he knew a starling which never made a mistake in saying in German "good morning" to persons arriving,

and "good bye, old fellow," to those departing. I could add several other such cases.) The lower animals

differ from man solely in his almost infinitely larger power of associating together the most diversified

sounds and ideas; and this obviously depends on the high development of his mental powers.

As Horne Tooke, one of the founders of the noble science of philology, observes, language is an art, like

brewing or baking; but writing would have been a better simile. It certainly is not a true instinct, for every

language has to be learnt. It differs, however, widely from all ordinary arts, for man has an instinctive

tendency to speak, as we see in the babble of our young children; whilst no child has an instinctive tendency

to brew, bake, or write. Moreover, no philologist now supposes that any language has been deliberately

invented; it has been slowly and unconsciously developed by many steps. (53. See some good remarks on this

head by Prof. Whitney, in his 'Oriental and Linguistic Studies,' 1873, p. 354. He observes that the desire of

communication between man is the living force, which, in the development of language, "works both

consciously and unconsciously; consciously as regards the immediate end to be attained; unconsciously as

regards the further consequences of the act.") The sounds uttered by birds offer in several respects the nearest

analogy to language, for all the members of the same species utter the same instinctive cries expressive of

their emotions; and all the kinds which sing, exert their power instinctively; but the actual song, and even the

callnotes, are learnt from their parents or fosterparents. These sounds, as Daines Barrington (54. Hon.

Daines Barrington in 'Philosoph. Transactions,' 1773, p. 262. See also Dureau de la Malle, in 'Ann. des. Sc.

Nat.' 3rd series, Zoolog., tom. x. p. 119.) has proved, "are no more innate than language is in man." The first

attempts to sing "may be compared to the imperfect endeavour in a child to babble." The young males

continue practising, or as the birdcatchers say, "recording," for ten or eleven months. Their first essays shew

hardly a rudiment of the future song; but as they grow older we can perceive what they are aiming at; and at

last they are said "to sing their song round." Nestlings which have learnt the song of a distinct species, as with

the canarybirds educated in the Tyrol, teach and transmit their new song to their offspring. The slight

natural differences of song in the same species inhabiting different districts may be appositely compared, as

Barrington remarks, "to provincial dialects"; and the songs of allied, though distinct species may be compared

with the languages of distinct races of man. I have given the foregoing details to shew that an instinctive

With respect to the origin of articulate language, after having read on the one side the highly interesting

works of Mr. Hensleigh Wedgwood, the Rev. F. Farrar, and Prof. Schleicher (55. 'On the Origin of

Language,' by H. Wedgwood, 1866. 'Chapters on Language,' by the Rev. F.W. Farrar, 1865. These works are

most interesting. See also 'De la Phys. et de Parole,' par Albert Lemoine, 1865, p. 190. The work on this

subject, by the late Prof. Aug. Schleicher, has been translated by Dr. Bikkers into English, under the title of

'Darwinism tested by the Science of Language,' 1869.), and the celebrated lectures of Prof. Max Muller on

the other side, I cannot doubt that language owes its origin to the imitation and modification of various

natural sounds, the voices of other animals, and man's own instinctive cries, aided by signs and gestures.

When we treat of sexual selection we shall see that primeval man, or rather some early progenitor of man,

probably first used his voice in producing true musical cadences, that is in singing, as do some of the

gibbonapes at the present day; and we may conclude from a widelyspread analogy, that this power would

have been especially exerted during the courtship of the sexes,would have expressed various emotions,

such as love, jealousy, triumph,and would have served as a challenge to rivals. It is, therefore, probable

that the imitation of musical cries by articulate sounds may have given rise to words expressive of various

complex emotions. The strong tendency in our nearest allies, the monkeys, in microcephalous idiots (56.

Vogt, 'Memoire sur les Microcephales,' 1867, p. 169. With respect to savages, I have given some facts in my

'Journal of Researches,' etc., 1845, p. 206.), and in the barbarous races of mankind, to imitate whatever they

hear deserves notice, as bearing on the subject of imitation. Since monkeys certainly understand much that is

said to them by man, and when wild, utter signalcries of danger to their fellows (57. See clear evidence on

this head in the two works so often quoted, by Brehm and Rengger.); and since fowls give distinct warnings

for danger on the ground, or in the sky from hawks (both, as well as a third cry, intelligible to dogs) (58.

Houzeau gives a very curious account of his observations on this subject in his 'Facultes Mentales des

Animaux,' tom. ii. p. 348.), may not some unusually wise ape like animal have imitated the growl of a beast

of prey, and thus told his fellowmonkeys the nature of the expected danger? This would have been a first

As the voice was used more and more, the vocal organs would have been strengthened and perfected through

the principle of the inherited effects of use; and this would have reacted on the power of speech. But the

relation between the continued use of language and the development of the brain, has no doubt been far more

important. The mental powers in some early progenitor of man must have been more highly developed than

in any existing ape, before even the most imperfect form of speech could have come into use; but we may

confidently believe that the continued use and advancement of this power would have reacted on the mind

itself, by enabling and encouraging it to carry on long trains of thought. A complex train of thought can no

more be carried on without the aid of words, whether spoken or silent, than a long calculation without the use

of figures or algebra. It appears, also, that even an ordinary train of thought almost requires, or is greatly

facilitated by some form of language, for the dumb, deaf, and blind girl, Laura Bridgman, was observed to

use her fingers whilst dreaming. (59. See remarks on this head by Dr. Maudsley, 'The Physiology and

Pathology of Mind,' 2nd ed., 1868, p. 199.) Nevertheless, a long succession of vivid and connected ideas may

pass through the mind without the aid of any form of language, as we may infer from the movements of dogs

during their dreams. We have, also, seen that animals are able to reason to a certain extent, manifestly

without the aid of language. The intimate connection between the brain, as it is now developed in us, and the

faculty of speech, is well shewn by those curious cases of braindisease in which speech is specially affected,

as when the power to remember substantives is lost, whilst other words can be correctly used, or where

substantives of a certain class, or all except the initial letters of substantives and proper names are forgotten.

(60. Many curious cases have been recorded. See, for instance, Dr. Bateman 'On Aphasia,' 1870, pp. 27, 31,

53, 100, etc. Also, 'Inquiries Concerning the Intellectual Powers,' by Dr. Abercrombie, 1838, p. 150.) There is

no more improbability in the continued use of the mental and vocal organs leading to inherited changes in

their structure and functions, than in the case of handwriting, which depends partly on the form of the hand

and partly on the disposition of the mind; and handwriting is certainly inherited. (61. 'The Variation of

Several writers, more especially Prof. Max Muller (62. Lectures on 'Mr. Darwin's Philosophy of Language,'

1873.), have lately insisted that the use of language implies the power of forming general concepts; and that

as no animals are supposed to possess this power, an impassable barrier is formed between them and man.

(63. The judgment of a distinguished philologist, such as Prof. Whitney, will have far more weight on this

point than anything that I can say. He remarks ('Oriental and Linguistic Studies,' 1873, p. 297), in speaking of

Bleek's views: "Because on the grand scale language is the necessary auxiliary of thought, indispensable to

the development of the power of thinking, to the distinctness and variety and complexity of cognitions to the

full mastery of consciousness; therefore he would fain make thought absolutely impossible without speech,

identifying the faculty with its instrument. He might just as reasonably assert that the human hand cannot act

without a tool. With such a doctrine to start from, he cannot stop short of Max Muller's worst paradoxes, that

an infant (in fans, not speaking) is not a human being, and that deafmutes do not become possessed of

reason until they learn to twist their fingers into imitation of spoken words." Max Muller gives in italics

('Lectures on Mr. Darwin's Philosophy of Language,' 1873, third lecture) this aphorism: "There is no thought

without words, as little as there are words without thought." What a strange definition must here be given to

the word thought!) With respect to animals, I have already endeavoured to shew that they have this power, at

least in a rude and incipient degree. As far as concerns infants of from ten to eleven months old, and

deafmutes, it seems to me incredible, that they should be able to connect certain sounds with certain general

ideas as quickly as they do, unless such ideas were already formed in their minds. The same remark may be

extended to the more intelligent animals; as Mr. Leslie Stephen observes (64. 'Essays on Free Thinking,' etc.,

1873, p. 82.), "A dog frames a general concept of cats or sheep, and knows the corresponding words as well

as a philosopher. And the capacity to understand is as good a proof of vocal intelligence, though in an inferior

Why the organs now used for speech should have been originally perfected for this purpose, rather than any

other organs, it is not difficult to see. Ants have considerable powers of intercommunication by means of

their antennae, as shewn by Huber, who devotes a whole chapter to their language. We might have used our

fingers as efficient instruments, for a person with practice can report to a deaf man every word of a speech

rapidly delivered at a public meeting; but the loss of our hands, whilst thus employed, would have been a

serious inconvenience. As all the higher mammals possess vocal organs, constructed on the same general plan

as ours, and used as a means of communication, it was obviously probable that these same organs would be

still further developed if the power of communication had to be improved; and this has been effected by the

aid of adjoining and well adapted parts, namely the tongue and lips. (65. See some good remarks to this effect

by Dr. Maudsley, 'The Physiology and Pathology of Mind,' 1868, p. 199.) The fact of the higher apes not

using their vocal organs for speech, no doubt depends on their intelligence not having been sufficiently

advanced. The possession by them of organs, which with longcontinued practice might have been used for

speech, although not thus used, is paralleled by the case of many birds which possess organs fitted for

singing, though they never sing. Thus, the nightingale and crow have vocal organs similarly constructed,

these being used by the former for diversified song, and by the latter only for croaking. (66. Macgillivray,

'Hist. of British Birds,' vol. ii. 1839, p. 29. An excellent observer, Mr. Blackwall, remarks that the magpie

learns to pronounce single words, and even short sentences, more readily than almost any other British bird;

yet, as he adds, after long and closely investigating its habits, he has never known it, in a state of nature,

display any unusual capacity for imitation. 'Researches in Zoology,' 1834, p. 158.) If it be asked why apes

have not had their intellects developed to the same degree as that of man, general causes only can be assigned

in answer, and it is unreasonable to expect any thing more definite, considering our ignorance with respect to

The formation of different languages and of distinct species, and the proofs that both have been developed

through a gradual process, are curiously parallel. (67. See the very interesting parallelism between the

development of species and languages, given by Sir C. Lyell in 'The Geological Evidences of the Antiquity of

Man,' 1863, chap. xxiii.) But we can trace the formation of many words further back than that of species, for

we can perceive how they actually arose from the imitation of various sounds. We find in distinct languages

striking homologies due to community of descent, and analogies due to a similar process of formation. The

manner in which certain letters or sounds change when others change is very like correlated growth. We have

in both cases the reduplication of parts, the effects of longcontinued use, and so forth. The frequent presence

of rudiments, both in languages and in species, is still more remarkable. The letter m in the word am, means

I; so that in the expression I am, a superfluous and useless rudiment has been retained. In the spelling also of

words, letters often remain as the rudiments of ancient forms of pronunciation. Languages, like organic

beings, can be classed in groups under groups; and they can be classed either naturally according to descent,

or artificially by other characters. Dominant languages and dialects spread widely, and lead to the gradual

extinction of other tongues. A language, like a species, when once extinct, never, as Sir C. Lyell remarks,

reappears. The same language never has two birthplaces. Distinct languages may be crossed or blended

together. (68. See remarks to this effect by the Rev. F.W. Farrar, in an interesting article, entitled 'Philology

and Darwinism,' in 'Nature,' March 24th, 1870, p. 528.) We see variability in every tongue, and new words

are continually cropping up; but as there is a limit to the powers of the memory, single words, like whole

languages, gradually become extinct. As Max Muller (69. 'Nature,' January 6th, 1870, p. 257.) has well

remarked:"A struggle for life is constantly going on amongst the words and grammatical forms in each

language. The better, the shorter, the easier forms are constantly gaining the upper hand, and they owe their

success to their own inherent virtue." To these more important causes of the survival of certain words, mere

novelty and fashion may be added; for there is in the mind of man a strong love for slight changes in all

things. The survival or preservation of certain favoured words in the struggle for existence is natural

The perfectly regular and wonderfully complex construction of the languages of many barbarous nations has

often been advanced as a proof, either of the divine origin of these languages, or of the high art and former

civilisation of their founders. Thus F. von Schlegel writes: "In those languages which appear to be at the

lowest grade of intellectual culture, we frequently observe a very high and elaborate degree of art in their

grammatical structure. This is especially the case with the Basque and the Lapponian, and many of the

American languages." (70. Quoted by C.S. Wake, 'Chapters on Man,' 1868, p. 101.) But it is assuredly an

error to speak of any language as an art, in the sense of its having been elaborately and methodically formed.

Philologists now admit that conjugations, declensions, etc., originally existed as distinct words, since joined

together; and as such words express the most obvious relations between objects and persons, it is not

surprising that they should have been used by the men of most races during the earliest ages. With respect to

perfection, the following illustration will best shew how easily we may err: a Crinoid sometimes consists of

no less than 150,000 pieces of shell (71. Buckland, 'Bridgewater Treatise,' p. 411.), all arranged with perfect

symmetry in radiating lines; but a naturalist does not consider an animal of this kind as more perfect than a

bilateral one with comparatively few parts, and with none of these parts alike, excepting on the opposite sides

of the body. He justly considers the differentiation and specialisation of organs as the test of perfection. So

with languages: the most symmetrical and complex ought not to be ranked above irregular, abbreviated, and

bastardised languages, which have borrowed expressive words and useful forms of construction from various

From these few and imperfect remarks I conclude that the extremely complex and regular construction of

many barbarous languages, is no proof that they owe their origin to a special act of creation. (72. See some

good remarks on the simplification of languages, by Sir J. Lubbock, 'Origin of Civilisation,' 1870, p. 278.)

Nor, as we have seen, does the faculty of articulate speech in itself offer any insuperable objection to the

This sense has been declared to be peculiar to man. I refer here only to the pleasure given by certain colours,

forms, and sounds, and which may fairly be called a sense of the beautiful; with cultivated men such

sensations are, however, intimately associated with complex ideas and trains of thought. When we behold a

male bird elaborately displaying his graceful plumes or splendid colours before the female, whilst other birds,

not thus decorated, make no such display, it is impossible to doubt that she admires the beauty of her male

partner. As women everywhere deck themselves with these plumes, the beauty of such ornaments cannot be

disputed. As we shall see later, the nests of hummingbirds, and the playing passages of bowerbirds are

tastefully ornamented with gaily coloured objects; and this shews that they must receive some kind of

pleasure from the sight of such things. With the great majority of animals, however, the taste for the beautiful

is confined, as far as we can judge, to the attractions of the opposite sex. The sweet strains poured forth by

many male birds during the season of love, are certainly admired by the females, of which fact evidence will

hereafter be given. If female birds had been incapable of appreciating the beautiful colours, the ornaments,

and voices of their male partners, all the labour and anxiety exhibited by the latter in displaying their charms

before the females would have been thrown away; and this it is impossible to admit. Why certain bright

colours should excite pleasure cannot, I presume, be explained, any more than why certain flavours and

scents are agreeable; but habit has something to do with the result, for that which is at first unpleasant to our

senses, ultimately becomes pleasant, and habits are inherited. With respect to sounds, Helmholtz has

explained to a certain extent on physiological principles, why harmonies and certain cadences are agreeable.

But besides this, sounds frequently recurring at irregular intervals are highly disagreeable, as every one will

admit who has listened at night to the irregular flapping of a rope on board ship. The same principle seems to

come into play with vision, as the eye prefers symmetry or figures with some regular recurrence. Patterns of

this kind are employed by even the lowest savages as ornaments; and they have been developed through

sexual selection for the adornment of some male animals. Whether we can or not give any reason for the

pleasure thus derived from vision and hearing, yet man and many of the lower animals are alike pleased by

The taste for the beautiful, at least as far as female beauty is concerned, is not of a special nature in the

human mind; for it differs widely in the different races of man, and is not quite the same even in the different

nations of the same race. Judging from the hideous ornaments, and the equally hideous music admired by

most savages, it might be urged that their aesthetic faculty was not so highly developed as in certain animals,

for instance, as in birds. Obviously no animal would be capable of admiring such scenes as the heavens at

night, a beautiful landscape, or refined music; but such high tastes are acquired through culture, and depend

on complex associations; they are not enjoyed by barbarians or by uneducated persons.

Many of the faculties, which have been of inestimable service to man for his progressive advancement, such

as the powers of the imagination, wonder, curiosity, an undefined sense of beauty, a tendency to imitation,

and the love of excitement or novelty, could hardly fail to lead to capricious changes of customs and fashions.

I have alluded to this point, because a recent writer (73. 'The Spectator,' Dec. 4th, 1869, p. 1430.) has oddly

fixed on Caprice "as one of the most remarkable and typical differences between savages and brutes." But not

only can we partially understand how it is that man is from various conflicting influences rendered

capricious, but that the lower animals are, as we shall hereafter see, likewise capricious in their affections,

aversions, and sense of beauty. There is also reason to suspect that they love novelty, for its own sake.

There is no evidence that man was aboriginally endowed with the ennobling belief in the existence of an

Omnipotent God. On the contrary there is ample evidence, derived not from hasty travellers, but from men

who have long resided with savages, that numerous races have existed, and still exist, who have no idea of

one or more gods, and who have no words in their languages to express such an idea. (74. See an excellent

article on this subject by the Rev. F.W. Farrar, in the 'Anthropological Review,' Aug. 1864, p. ccxvii. For

further facts see Sir J. Lubbock, 'Prehistoric Times,' 2nd edit., 1869, p. 564; and especially the chapters on

Religion in his 'Origin of Civilisation,' 1870.) The question is of course wholly distinct from that higher one,

whether there exists a Creator and Ruler of the universe; and this has been answered in the affirmative by

If, however, we include under the term "religion" the belief in unseen or spiritual agencies, the case is wholly

different; for this belief seems to be universal with the less civilised races. Nor is it difficult to comprehend

how it arose. As soon as the important faculties of the imagination, wonder, and curiosity, together with some

power of reasoning, had become partially developed, man would naturally crave to understand what was

passing around him, and would have vaguely speculated on his own existence. As Mr. M'Lennan (75. 'The

Worship of Animals and Plants,' in the 'Fortnightly Review,' Oct. 1, 1869, p. 422.) has remarked, "Some

explanation of the phenomena of life, a man must feign for himself, and to judge from the universality of it,

the simplest hypothesis, and the first to occur to men, seems to have been that natural phenomena are

ascribable to the presence in animals, plants, and things, and in the forces of nature, of such spirits prompting

to action as men are conscious they themselves possess." It is also probable, as Mr. Tylor has shewn, that

dreams may have first given rise to the notion of spirits; for savages do not readily distinguish between

subjective and objective impressions. When a savage dreams, the figures which appear before him are

believed to have come from a distance, and to stand over him; or "the soul of the dreamer goes out on its

travels, and comes home with a remembrance of what it has seen." (76. Tylor, 'Early History of Mankind,'

1865, p. 6. See also the three striking chapters on the 'Development of Religion,' in Lubbock's 'Origin of

Civilisation,' 1870. In a like manner Mr. Herbert Spencer, in his ingenious essay in the 'Fortnightly Review'

(May 1st, 1870, p. 535), accounts for the earliest forms of religious belief throughout the world, by man being

led through dreams, shadows, and other causes, to look at himself as a double essence, corporeal and

spiritual. As the spiritual being is supposed to exist after death and to be powerful, it is propitiated by various

gifts and ceremonies, and its aid invoked. He then further shews that names or nicknames given from some

animal or other object, to the early progenitors or founders of a tribe, are supposed after a long interval to

represent the real progenitor of the tribe; and such animal or object is then naturally believed still to exist as a

spirit, is held sacred, and worshipped as a god. Nevertheless I cannot but suspect that there is a still earlier

and ruder stage, when anything which manifests power or movement is thought to be endowed with some

form of life, and with mental faculties analogous to our own.) But until the faculties of imagination, curiosity,

reason, etc., had been fairly well developed in the mind of man, his dreams would not have led him to believe

The tendency in savages to imagine that natural objects and agencies are animated by spiritual or living

essences, is perhaps illustrated by a little fact which I once noticed: my dog, a fullgrown and very sensible

animal, was lying on the lawn during a hot and still day; but at a little distance a slight breeze occasionally

moved an open parasol, which would have been wholly disregarded by the dog, had any one stood near it. As

it was, every time that the parasol slightly moved, the dog growled fiercely and barked. He must, I think,

have reasoned to himself in a rapid and unconscious manner, that movement without any apparent cause

indicated the presence of some strange living agent, and that no stranger had a right to be on his territory.

The belief in spiritual agencies would easily pass into the belief in the existence of one or more gods. For

savages would naturally attribute to spirits the same passions, the same love of vengeance or simplest form of

justice, and the same affections which they themselves feel. The Fuegians appear to be in this respect in an

intermediate condition, for when the surgeon on board the "Beagle" shot some young ducklings as specimens,

York Minster declared in the most solemn manner, "Oh, Mr. Bynoe, much rain, much snow, blow much";

and this was evidently a retributive punishment for wasting human food. So again he related how, when his

brother killed a "wild man," storms long raged, much rain and snow fell. Yet we could never discover that the

Fuegians believed in what we should call a God, or practised any religious rites; and Jemmy Button, with

justifiable pride, stoutly maintained that there was no devil in his land. This latter assertion is the more

remarkable, as with savages the belief in bad spirits is far more common than that in good ones.

The feeling of religious devotion is a highly complex one, consisting of love, complete submission to an

exalted and mysterious superior, a strong sense of dependence (77. See an able article on the 'Physical

Elements of Religion,' by Mr. L. Owen Pike, in 'Anthropological Review,' April 1870, p. lxiii.), fear,

reverence, gratitude, hope for the future, and perhaps other elements. No being could experience so complex

an emotion until advanced in his intellectual and moral faculties to at least a moderately high level.

Nevertheless, we see some distant approach to this state of mind in the deep love of a dog for his master,

associated with complete submission, some fear, and perhaps other feelings. The behaviour of a dog when

returning to his master after an absence, and, as I may add, of a monkey to his beloved keeper, is widely

different from that towards their fellows. In the latter case the transports of joy appear to be somewhat less,

and the sense of equality is shewn in every action. Professor Braubach goes so far as to maintain that a dog

looks on his master as on a god. (78. 'Religion, Moral, etc., der Darwin'schen ArtLehre,' 1869, s. 53. It is

said (Dr. W. Lauder Lindsay, 'Journal of Mental Science,' 1871, p. 43), that Bacon long ago, and the poet

The same high mental faculties which first led man to believe in unseen spiritual agencies, then in fetishism,

polytheism, and ultimately in monotheism, would infallibly lead him, as long as his reasoning powers

remained poorly developed, to various strange superstitions and customs. Many of these are terrible to think

ofsuch as the sacrifice of human beings to a bloodloving god; the trial of innocent persons by the ordeal

of poison or fire; witchcraft, etc.yet it is well occasionally to reflect on these superstitions, for they shew

us what an infinite debt of gratitude we owe to the improvement of our reason, to science, and to our

accumulated knowledge. As Sir J. Lubbock (79. 'Prehistoric Times,' 2nd edit., p. 571. In this work (p. 571)

there will be found an excellent account of the many strange and capricious customs of savages.) has well

observed, "it is not too much to say that the horrible dread of unknown evil hangs like a thick cloud over

savage life, and embitters every pleasure." These miserable and indirect consequences of our highest faculties

may be compared with the incidental and occasional mistakes of the instincts of the lower animals.

sociabilityStruggle between opposed instinctsMan a social animalThe more enduring social instincts

conquer other less persistent instinctsThe social virtues alone regarded by savagesThe selfregarding

virtues acquired at a later stage of developmentThe importance of the judgment of the members of the

I fully subscribe to the judgment of those writers (1. See, for instance, on this subject, Quatrefages, 'Unite de

l'Espece Humaine,' 1861, p. 21, etc.) who maintain that of all the differences between man and the lower

animals, the moral sense or conscience is by far the most important. This sense, as Mackintosh (2.

'Dissertation an Ethical Philosophy,' 1837, p. 231, etc.) remarks, "has a rightful supremacy over every other

principle of human action"; it is summed up in that short but imperious word "ought," so full of high

significance. It is the most noble of all the attributes of man, leading him without a moment's hesitation to

risk his life for that of a fellowcreature; or after due deliberation, impelled simply by the deep feeling of

right or duty, to sacrifice it in some great cause. Immanuel Kant exclaims, "Duty! Wondrous thought, that

workest neither by fond insinuation, flattery, nor by any threat, but merely by holding up thy naked law in the

soul, and so extorting for thyself always reverence, if not always obedience; before whom all appetites are

dumb, however secretly they rebel; whence thy original?" (3. 'Metaphysics of Ethics,' translated by J.W.

This great question has been discussed by many writers (4. Mr. Bain gives a list ('Mental and Moral Science,'

1868, pp. 543725) of twentysix British authors who have written on this subject, and whose names are

familiar to every reader; to these, Mr. Bain's own name, and those of Mr. Lecky, Mr. Shadworth Hodgson,

Sir J. Lubbock, and others, might be added.) of consummate ability; and my sole excuse for touching on it, is

the impossibility of here passing it over; and because, as far as I know, no one has approached it exclusively

from the side of natural history. The investigation possesses, also, some independent interest, as an attempt to

see how far the study of the lower animals throws light on one of the highest psychical faculties of man.

The following proposition seems to me in a high degree probablenamely, that any animal whatever,

endowed with wellmarked social instincts (5. Sir B. Brodie, after observing that man is a social animal

('Psychological Enquiries,' 1854, p. 192), asks the pregnant question, "ought not this to settle the disputed

question as to the existence of a moral sense?" Similar ideas have probably occurred to many persons, as they

did long ago to Marcus Aurelius. Mr. J.S. Mill speaks, in his celebrated work, 'Utilitarianism,' (1864, pp. 45,

46), of the social feelings as a "powerful natural sentiment," and as "the natural basis of sentiment for

utilitarian morality." Again he says, "Like the other acquired capacities above referred to, the moral faculty, if

not a part of our nature, is a natural outgrowth from it; capable, like them, in a certain small degree of

springing up spontaneously." But in opposition to all this, he also remarks, "if, as in my own belief, the moral

feelings are not innate, but acquired, they are not for that reason less natural." It is with hesitation that I

venture to differ at all from so profound a thinker, but it can hardly be disputed that the social feelings are

instinctive or innate in the lower animals; and why should they not be so in man? Mr. Bain (see, for instance,

'The Emotions and the Will,' 1865, p. 481) and others believe that the moral sense is acquired by each

individual during his lifetime. On the general theory of evolution this is at least extremely improbable. The

ignoring of all transmitted mental qualities will, as it seems to me, be hereafter judged as a most serious

blemish in the works of Mr. Mill.), the parental and filial affections being here included, would inevitably

acquire a moral sense or conscience, as soon as its intellectual powers had become as well, or nearly as well

developed, as in man. For, FIRSTLY, the social instincts lead an animal to take pleasure in the society of its

fellows, to feel a certain amount of sympathy with them, and to perform various services for them. The

services may be of a definite and evidently instinctive nature; or there may be only a wish and readiness, as

with most of the higher social animals, to aid their fellows in certain general ways. But these feelings and

services are by no means extended to all the individuals of the same species, only to those of the same

association. SECONDLY, as soon as the mental faculties had become highly developed, images of all past

actions and motives would be incessantly passing through the brain of each individual: and that feeling of

dissatisfaction, or even misery, which invariably results, as we shall hereafter see, from any unsatisfied

instinct, would arise, as often as it was perceived that the enduring and always present social instinct had

yielded to some other instinct, at the time stronger, but neither enduring in its nature, nor leaving behind it a

very vivid impression. It is clear that many instinctive desires, such as that of hunger, are in their nature of

short duration; and after being satisfied, are not readily or vividly recalled. THIRDLY, after the power of

language had been acquired, and the wishes of the community could be expressed, the common opinion how

each member ought to act for the public good, would naturally become in a paramount degree the guide to

action. But it should be borne in mind that however great weight we may attribute to public opinion, our

regard for the approbation and disapprobation of our fellows depends on sympathy, which, as we shall see,

forms an essential part of the social instinct, and is indeed its foundationstone. LASTLY, habit in the

individual would ultimately play a very important part in guiding the conduct of each member; for the social

instinct, together with sympathy, is, like any other instinct, greatly strengthened by habit, and so consequently

would be obedience to the wishes and judgment of the community. These several subordinate propositions

It may be well first to premise that I do not wish to maintain that any strictly social animal, if its intellectual

faculties were to become as active and as highly developed as in man, would acquire exactly the same moral

sense as ours. In the same manner as various animals have some sense of beauty, though they admire

widelydifferent objects, so they might have a sense of right and wrong, though led by it to follow widely

different lines of conduct. If, for instance, to take an extreme case, men were reared under precisely the same

conditions as hivebees, there can hardly be a doubt that our unmarried females would, like the workerbees,

think it a sacred duty to kill their brothers, and mothers would strive to kill their fertile daughters; and no one

would think of interfering. (6. Mr. H. Sidgwick remarks, in an able discussion on this subject (the 'Academy,'

June 15, 1872, p. 231), "a superior bee, we may feel sure, would aspire to a milder solution of the population

question." Judging, however, from the habits of many or most savages, man solves the problem by female

infanticide, polyandry and promiscuous intercourse; therefore it may well be doubted whether it would be by

a milder method. Miss Cobbe, in commenting ('Darwinism in Morals,' 'Theological Review,' April 1872, pp.

188191) on the same illustration, says, the PRINCIPLES of social duty would be thus reversed; and by this,

I presume, she means that the fulfilment of a social duty would tend to the injury of individuals; but she

overlooks the fact, which she would doubtless admit, that the instincts of the bee have been acquired for the

good of the community. She goes so far as to say that if the theory of ethics advocated in this chapter were

ever generally accepted, "I cannot but believe that in the hour of their triumph would be sounded the knell of

the virtue of mankind!" It is to be hoped that the belief in the permanence of virtue on this earth is not held by

many persons on so weak a tenure.) Nevertheless, the bee, or any other social animal, would gain in our

supposed case, as it appears to me, some feeling of right or wrong, or a conscience. For each individual

would have an inward sense of possessing certain stronger or more enduring instincts, and others less strong

or enduring; so that there would often be a struggle as to which impulse should be followed; and satisfaction,

dissatisfaction, or even misery would be felt, as past impressions were compared during their incessant

passage through the mind. In this case an inward monitor would tell the animal that it would have been better

to have followed the one impulse rather than the other. The one course ought to have been followed, and the

other ought not; the one would have been right and the other wrong; but to these terms I shall recur.

Animals of many kinds are social; we find even distinct species living together; for example, some American

monkeys; and united flocks of rooks, jackdaws, and starlings. Man shews the same feeling in his strong love

for the dog, which the dog returns with interest. Every one must have noticed how miserable horses, dogs,

sheep, etc., are when separated from their companions, and what strong mutual affection the two former

kinds, at least, shew on their reunion. It is curious to speculate on the feelings of a dog, who will rest

peacefully for hours in a room with his master or any of the family, without the least notice being taken of

him; but if left for a short time by himself, barks or howls dismally. We will confine our attention to the

higher social animals; and pass over insects, although some of these are social, and aid one another in many

important ways. The most common mutual service in the higher animals is to warn one another of danger by

means of the united senses of all. Every sportsman knows, as Dr. Jaeger remarks (7. 'Die Darwin'sche

Theorie,' s. 101.), how difficult it is to approach animals in a herd or troop. Wild horses and cattle do not, I

believe, make any dangersignal; but the attitude of any one of them who first discovers an enemy, warns the

others. Rabbits stamp loudly on the ground with their hindfeet as a signal: sheep and chamois do the same

with their forefeet, uttering likewise a whistle. Many birds, and some mammals, post sentinels, which in the

case of seals are said (8. Mr. R. Brown in 'Proc. Zoolog. Soc.' 1868, p. 409.) generally to be the females. The

leader of a troop of monkeys acts as the sentinel, and utters cries expressive both of danger and of safety. (9.

Brehm, 'Thierleben,' B. i. 1864, s. 52, 79. For the case of the monkeys extracting thorns from each other, see

s. 54. With respect to the Hamadryas turning over stones, the fact is given (s. 76), on the evidence of Alvarez,

whose observations Brehm thinks quite trustworthy. For the cases of the old male baboons attacking the dogs,

see s. 79; and with respect to the eagle, s. 56.) Social animals perform many little services for each other:

horses nibble, and cows lick each other, on any spot which itches: monkeys search each other for external

parasites; and Brehm states that after a troop of the Cercopithecus griseoviridis has rushed through a thorny

brake, each monkey stretches itself on a branch, and another monkey sitting by, "conscientiously" examines

Animals also render more important services to one another: thus wolves and some other beasts of prey hunt

in packs, and aid one another in attacking their victims. Pelicans fish in concert. The Hamadryas baboons turn

over stones to find insects, etc.; and when they come to a large one, as many as can stand round, turn it over

together and share the booty. Social animals mutually defend each other. Bull bisons in N. America, when

there is danger, drive the cows and calves into the middle of the herd, whilst they defend the outside. I shall

also in a future chapter give an account of two young wild bulls at Chillingham attacking an old one in

concert, and of two stallions together trying to drive away a third stallion from a troop of mares. In Abyssinia,

Brehm encountered a great troop of baboons who were crossing a valley: some had already ascended the

opposite mountain, and some were still in the valley; the latter were attacked by the dogs, but the old males

immediately hurried down from the rocks, and with mouths widely opened, roared so fearfully, that the dogs

quickly drew back. They were again encouraged to the attack; but by this time all the baboons had reascended

the heights, excepting a young one, about six months old, who, loudly calling for aid, climbed on a block of

rock, and was surrounded. Now one of the largest males, a true hero, came down again from the mountain,

slowly went to the young one, coaxed him, and triumphantly led him awaythe dogs being too much

astonished to make an attack. I cannot resist giving another scene which was witnessed by this same

naturalist; an eagle seized a young Cercopithecus, which, by clinging to a branch, was not at once carried off;

it cried loudly for assistance, upon which the other members of the troop, with much uproar, rushed to the

rescue, surrounded the eagle, and pulled out so many feathers, that he no longer thought of his prey, but only

how to escape. This eagle, as Brehm remarks, assuredly would never again attack a single monkey of a troop.

(10. Mr. Belt gives the case of a spidermonkey (Ateles) in Nicaragua, which was heard screaming for nearly

two hours in the forest, and was found with an eagle perched close by it. The bird apparently feared to attack

as long as it remained face to face; and Mr. Belt believes, from what he has seen of the habits of these

monkeys, that they protect themselves from eagles by keeping two or three together. 'The Naturalist in

It is certain that associated animals have a feeling of love for each other, which is not felt by nonsocial adult

animals. How far in most cases they actually sympathise in the pains and pleasures of others, is more

doubtful, especially with respect to pleasures. Mr. Buxton, however, who had excellent means of observation

(11. 'Annals and Magazine of Natural History,' November 1868, p. 382.), states that his macaws, which lived

free in Norfolk, took "an extravagant interest" in a pair with a nest; and whenever the female left it, she was

surrounded by a troop "screaming horrible acclamations in her honour." It is often difficult to judge whether

animals have any feeling for the sufferings of others of their kind. Who can say what cows feel, when they

surround and stare intently on a dying or dead companion; apparently, however, as Houzeau remarks, they

feel no pity. That animals sometimes are far from feeling any sympathy is too certain; for they will expel a

wounded animal from the herd, or gore or worry it to death. This is almost the blackest fact in natural history,

unless, indeed, the explanation which has been suggested is true, that their instinct or reason leads them to

expel an injured companion, lest beasts of prey, including man, should be tempted to follow the troop. In this

case their conduct is not much worse than that of the North American Indians, who leave their feeble

comrades to perish on the plains; or the Fijians, who, when their parents get old, or fall ill, bury them alive.

Many animals, however, certainly sympathise with each other's distress or danger. This is the case even with

birds. Captain Stansbury (13. As quoted by Mr. L.H. Morgan, 'The American Beaver,' 1868, p. 272. Capt.

Stansbury also gives an interesting account of the manner in which a very young pelican, carried away by a

strong stream, was guided and encouraged in its attempts to reach the shore by half a dozen old birds.) found

on a salt lake in Utah an old and completely blind pelican, which was very fat, and must have been well fed

for a long time by his companions. Mr. Blyth, as he informs me, saw Indian crows feeding two or three of

their companions which were blind; and I have heard of an analogous case with the domestic cock. We may,

if we choose, call these actions instinctive; but such cases are much too rare for the development of any

special instinct. (14. As Mr. Bain states, "effective aid to a sufferer springs from sympathy proper:" 'Mental

and Moral Science,' 1868, p. 245.) I have myself seen a dog, who never passed a cat who lay sick in a basket,

and was a great friend of his, without giving her a few licks with his tongue, the surest sign of kind feeling in

It must be called sympathy that leads a courageous dog to fly at any one who strikes his master, as he

certainly will. I saw a person pretending to beat a lady, who had a very timid little dog on her lap, and the

trial had never been made before; the little creature instantly jumped away, but after the pretended beating

was over, it was really pathetic to see how perseveringly he tried to lick his mistress's face, and comfort her.

Brehm (15. 'Thierleben,' B. i. s. 85.) states that when a baboon in confinement was pursued to be punished,

the others tried to protect him. It must have been sympathy in the cases above given which led the baboons

and Cercopitheci to defend their young comrades from the dogs and the eagle. I will give only one other

instance of sympathetic and heroic conduct, in the case of a little American monkey. Several years ago a

keeper at the Zoological Gardens shewed me some deep and scarcely healed wounds on the nape of his own

neck, inflicted on him, whilst kneeling on the floor, by a fierce baboon. The little American monkey, who

was a warm friend of this keeper, lived in the same large compartment, and was dreadfully afraid of the great

baboon. Nevertheless, as soon as he saw his friend in peril, he rushed to the rescue, and by screams and bites

so distracted the baboon that the man was able to escape, after, as the surgeon thought, running great risk of

Besides love and sympathy, animals exhibit other qualities connected with the social instincts, which in us

would be called moral; and I agree with Agassiz (16. 'De l'Espece et de la Classe,' 1869, p. 97.) that dogs

Dogs possess some power of selfcommand, and this does not appear to be wholly the result of fear. As

Braubach (17. 'Die Darwin'sche ArtLehre,' 1869, s. 54.) remarks, they will refrain from stealing food in the

absence of their master. They have long been accepted as the very type of fidelity and obedience. But the

elephant is likewise very faithful to his driver or keeper, and probably considers him as the leader of the herd.

Dr. Hooker informs me that an elephant, which he was riding in India, became so deeply bogged that he

remained stuck fast until the next day, when he was extricated by men with ropes. Under such circumstances

elephants will seize with their trunks any object, dead or alive, to place under their knees, to prevent their

sinking deeper in the mud; and the driver was dreadfully afraid lest the animal should have seized Dr. Hooker

and crushed him to death. But the driver himself, as Dr. Hooker was assured, ran no risk. This forbearance

under an emergency so dreadful for a heavy animal, is a wonderful proof of noble fidelity. (18. See also

All animals living in a body, which defend themselves or attack their enemies in concert, must indeed be in

some degree faithful to one another; and those that follow a leader must be in some degree obedient. When

the baboons in Abyssinia (19. Brehm, 'Thierleben,' B. i. s. 76.) plunder a garden, they silently follow their

leader; and if an imprudent young animal makes a noise, he receives a slap from the others to teach him

silence and obedience. Mr. Galton, who has had excellent opportunities for observing the halfwild cattle in

S. Africa, says (20. See his extremely interesting paper on 'Gregariousness in Cattle, and in Man,'

'Macmillan's Magazine,' Feb. 1871, p. 353.), that they cannot endure even a momentary separation from the

herd. They are essentially slavish, and accept the common determination, seeking no better lot than to be led

by any one ox who has enough selfreliance to accept the position. The men who break in these animals for

harness, watch assiduously for those who, by grazing apart, shew a selfreliant disposition, and these they

train as foreoxen. Mr. Galton adds that such animals are rare and valuable; and if many were born they

would soon be eliminated, as lions are always on the lookout for the individuals which wander from the

With respect to the impulse which leads certain animals to associate together, and to aid one another in many

ways, we may infer that in most cases they are impelled by the same sense of satisfaction or pleasure which

they experience in performing other instinctive actions; or by the same sense of dissatisfaction as when other

instinctive actions are checked. We see this in innumerable instances, and it is illustrated in a striking manner

by the acquired instincts of our domesticated animals; thus a young shepherddog delights in driving and

running round a flock of sheep, but not in worrying them; a young foxhound delights in hunting a fox,

whilst some other kinds of dogs, as I have witnessed, utterly disregard foxes. What a strong feeling of inward

satisfaction must impel a bird, so full of activity, to brood day after day over her eggs. Migratory birds are

quite miserable if stopped from migrating; perhaps they enjoy starting on their long flight; but it is hard to

believe that the poor pinioned goose, described by Audubon, which started on foot at the proper time for its

journey of probably more than a thousand miles, could have felt any joy in doing so. Some instincts are

determined solely by painful feelings, as by fear, which leads to selfpreservation, and is in some cases

directed towards special enemies. No one, I presume, can analyse the sensations of pleasure or pain. In many

instances, however, it is probable that instincts are persistently followed from the mere force of inheritance,

without the stimulus of either pleasure or pain. A young pointer, when it first scents game, apparently cannot

help pointing. A squirrel in a cage who pats the nuts which it cannot eat, as if to bury them in the ground, can

hardly be thought to act thus, either from pleasure or pain. Hence the common assumption that men must be

impelled to every action by experiencing some pleasure or pain may be erroneous. Although a habit may be

blindly and implicitly followed, independently of any pleasure or pain felt at the moment, yet if it be forcibly

and abruptly checked, a vague sense of dissatisfaction is generally experienced.

It has often been assumed that animals were in the first place rendered social, and that they feel as a

consequence uncomfortable when separated from each other, and comfortable whilst together; but it is a more

probable view that these sensations were first developed, in order that those animals which would profit by

living in society, should be induced to live together, in the same manner as the sense of hunger and the

pleasure of eating were, no doubt, first acquired in order to induce animals to eat. The feeling of pleasure

from society is probably an extension of the parental or filial affections, since the social instinct seems to be

developed by the young remaining for a long time with their parents; and this extension may be attributed in

part to habit, but chiefly to natural selection. With those animals which were benefited by living in close

association, the individuals which took the greatest pleasure in society would best escape various dangers,

whilst those that cared least for their comrades, and lived solitary, would perish in greater numbers. With

respect to the origin of the parental and filial affections, which apparently lie at the base of the social

instincts, we know not the steps by which they have been gained; but we may infer that it has been to a large

extent through natural selection. So it has almost certainly been with the unusual and opposite feeling of

hatred between the nearest relations, as with the workerbees which kill their brother drones, and with the

queenbees which kill their daughterqueens; the desire to destroy their nearest relations having been in this

case of service to the community. Parental affection, or some feeling which replaces it, has been developed in

certain animals extremely low in the scale, for example, in starfishes and spiders. It is also occasionally

present in a few members alone in a whole group of animals, as in the genus Forficula, or earwigs.

The allimportant emotion of sympathy is distinct from that of love. A mother may passionately love her

sleeping and passive infant, but she can hardly at such times be said to feel sympathy for it. The love of a

man for his dog is distinct from sympathy, and so is that of a dog for his master. Adam Smith formerly

argued, as has Mr. Bain recently, that the basis of sympathy lies in our strong retentiveness of former states of

pain or pleasure. Hence, "the sight of another person enduring hunger, cold, fatigue, revives in us some

recollection of these states, which are painful even in idea." We are thus impelled to relieve the sufferings of

another, in order that our own painful feelings may be at the same time relieved. In like manner we are led to

participate in the pleasures of others. (21. See the first and striking chapter in Adam Smith's 'Theory of Moral

Sentiments.' Also 'Mr. Bain's Mental and Moral Science,' 1868, pp. 244, and 275282. Mr. Bain states, that,

"sympathy is, indirectly, a source of pleasure to the sympathiser"; and he accounts for this through

reciprocity. He remarks that "the person benefited, or others in his stead, may make up, by sympathy and

good offices returned, for all the sacrifice." But if, as appears to be the case, sympathy is strictly an instinct,

its exercise would give direct pleasure, in the same manner as the exercise, as before remarked, of almost

every other instinct.) But I cannot see how this view explains the fact that sympathy is excited, in an

immeasurably stronger degree, by a beloved, than by an indifferent person. The mere sight of suffering,

independently of love, would suffice to call up in us vivid recollections and associations. The explanation

may lie in the fact that, with all animals, sympathy is directed solely towards the members of the same

community, and therefore towards known, and more or less beloved members, but not to all the individuals of

the same species. This fact is not more surprising than that the fears of many animals should be directed

against special enemies. Species which are not social, such as lions and tigers, no doubt feel sympathy for the

suffering of their own young, but not for that of any other animal. With mankind, selfishness, experience, and

imitation, probably add, as Mr. Bain has shewn, to the power of sympathy; for we are led by the hope of

receiving good in return to perform acts of sympathetic kindness to others; and sympathy is much

strengthened by habit. In however complex a manner this feeling may have originated, as it is one of high

importance to all those animals which aid and defend one another, it will have been increased through natural

selection; for those communities, which included the greatest number of the most sympathetic members,

It is, however, impossible to decide in many cases whether certain social instincts have been acquired through

natural selection, or are the indirect result of other instincts and faculties, such as sympathy, reason,

experience, and a tendency to imitation; or again, whether they are simply the result of longcontinued habit.

So remarkable an instinct as the placing sentinels to warn the community of danger, can hardly have been the

indirect result of any of these faculties; it must, therefore, have been directly acquired. On the other hand, the

habit followed by the males of some social animals of defending the community, and of attacking their

enemies or their prey in concert, may perhaps have originated from mutual sympathy; but courage, and in

most cases strength, must have been previously acquired, probably through natural selection.

Of the various instincts and habits, some are much stronger than others; that is, some either give more

pleasure in their performance, and more distress in their prevention, than others; or, which is probably quite

as important, they are, through inheritance, more persistently followed, without exciting any special feeling

of pleasure or pain. We are ourselves conscious that some habits are much more difficult to cure or change

than others. Hence a struggle may often be observed in animals between different instincts, or between an

instinct and some habitual disposition; as when a dog rushes after a hare, is rebuked, pauses, hesitates,

pursues again, or returns ashamed to his master; or as between the love of a female dog for her young puppies

and for her master,for she may be seen to slink away to them, as if half ashamed of not accompanying her

master. But the most curious instance known to me of one instinct getting the better of another, is the

migratory instinct conquering the maternal instinct. The former is wonderfully strong; a confined bird will at

the proper season beat her breast against the wires of her cage, until it is bare and bloody. It causes young

salmon to leap out of the fresh water, in which they could continue to exist, and thus unintentionally to

commit suicide. Every one knows how strong the maternal instinct is, leading even timid birds to face great

danger, though with hesitation, and in opposition to the instinct of selfpreservation. Nevertheless, the

migratory instinct is so powerful, that late in the autumn swallows, housemartins, and swifts frequently

desert their tender young, leaving them to perish miserably in their nests. (22. This fact, the Rev. L. Jenyns

states (see his edition of 'White's Nat. Hist. of Selborne,' 1853, p. 204) was first recorded by the illustrious

Jenner, in 'Phil. Transact.' 1824, and has since been confirmed by several observers, especially by Mr.

Blackwall. This latter careful observer examined, late in the autumn, during two years, thirtysix nests; he

found that twelve contained young dead birds, five contained eggs on the point of being hatched, and three,

eggs not nearly hatched. Many birds, not yet old enough for a prolonged flight, are likewise deserted and left

behind. See Blackwall, 'Researches in Zoology,' 1834, pp. 108, 118. For some additional evidence, although

this is not wanted, see Leroy, 'Lettres Phil.' 1802, p. 217. For Swifts, Gould's 'Introduction to the Birds of

Great Britain,' 1823, p. 5. Similar cases have been observed in Canada by Mr. Adams; 'Pop. Science Review,'

We can perceive that an instinctive impulse, if it be in any way more beneficial to a species than some other

or opposed instinct, would be rendered the more potent of the two through natural selection; for the

individuals which had it most strongly developed would survive in larger numbers. Whether this is the case

with the migratory in comparison with the maternal instinct, may be doubted. The great persistence, or steady

action of the former at certain seasons of the year during the whole day, may give it for a time paramount

Every one will admit that man is a social being. We see this in his dislike of solitude, and in his wish for

society beyond that of his own family. Solitary confinement is one of the severest punishments which can be

inflicted. Some authors suppose that man primevally lived in single families; but at the present day, though

single families, or only two or three together, roam the solitudes of some savage lands, they always, as far as

I can discover, hold friendly relations with other families inhabiting the same district. Such families

occasionally meet in council, and unite for their common defence. It is no argument against savage man being

a social animal, that the tribes inhabiting adjacent districts are almost always at war with each other; for the

social instincts never extend to all the individuals of the same species. Judging from the analogy of the

majority of the Quadrumana, it is probable that the early apelike progenitors of man were likewise social;

but this is not of much importance for us. Although man, as he now exists, has few special instincts, having

lost any which his early progenitors may have possessed, this is no reason why he should not have retained

from an extremely remote period some degree of instinctive love and sympathy for his fellows. We are

indeed all conscious that we do possess such sympathetic feelings (23. Hume remarks ('An Enquiry

Concerning the Principles of Morals,' edit. of 1751, p. 132), "There seems a necessity for confessing that the

happiness and misery of others are not spectacles altogether indifferent to us, but that the view of the

former...communicates a secret joy; the appearance of the latter... throws a melancholy damp over the

imagination."); but our consciousness does not tell us whether they are instinctive, having originated long ago

in the same manner as with the lower animals, or whether they have been acquired by each of us during our

early years. As man is a social animal, it is almost certain that he would inherit a tendency to be faithful to his

comrades, and obedient to the leader of his tribe; for these qualities are common to most social animals. He

would consequently possess some capacity for selfcommand. He would from an inherited tendency be

willing to defend, in concert with others, his fellowmen; and would be ready to aid them in any way, which

The social animals which stand at the bottom of the scale are guided almost exclusively, and those which

stand higher in the scale are largely guided, by special instincts in the aid which they give to the members of

the same community; but they are likewise in part impelled by mutual love and sympathy, assisted apparently

by some amount of reason. Although man, as just remarked, has no special instincts to tell him how to aid his

fellow men, he still has the impulse, and with his improved intellectual faculties would naturally be much

guided in this respect by reason and experience. Instinctive sympathy would also cause him to value highly

the approbation of his fellows; for, as Mr. Bain has clearly shewn (24. 'Mental and Moral Science,' 1868, p.

254.), the love of praise and the strong feeling of glory, and the still stronger horror of scorn and infamy, "are

due to the workings of sympathy." Consequently man would be influenced in the highest degree by the

wishes, approbation, and blame of his fellowmen, as expressed by their gestures and language. Thus the

social instincts, which must have been acquired by man in a very rude state, and probably even by his early

apelike progenitors, still give the impulse to some of his best actions; but his actions are in a higher degree

determined by the expressed wishes and judgment of his fellowmen, and unfortunately very often by his

own strong selfish desires. But as love, sympathy and selfcommand become strengthened by habit, and as

the power of reasoning becomes clearer, so that man can value justly the judgments of his fellows, he will

feel himself impelled, apart from any transitory pleasure or pain, to certain lines of conduct. He might then

declarenot that any barbarian or uncultivated man could thus thinkI am the supreme judge of my own

conduct, and in the words of Kant, I will not in my own person violate the dignity of humanity.

We have not, however, as yet considered the main point, on which, from our present point of view, the whole

question of the moral sense turns. Why should a man feel that he ought to obey one instinctive desire rather

than another? Why is he bitterly regretful, if he has yielded to a strong sense of selfpreservation, and has not

risked his life to save that of a fellow creature? or why does he regret having stolen food from hunger?

It is evident in the first place, that with mankind the instinctive impulses have different degrees of strength; a

savage will risk his own life to save that of a member of the same community, but will be wholly indifferent

about a stranger: a young and timid mother urged by the maternal instinct will, without a moment's hesitation,

run the greatest danger for her own infant, but not for a mere fellowcreature. Nevertheless many a civilised

man, or even boy, who never before risked his life for another, but full of courage and sympathy, has

disregarded the instinct of selfpreservation, and plunged at once into a torrent to save a drowning man,

though a stranger. In this case man is impelled by the same instinctive motive, which made the heroic little

American monkey, formerly described, save his keeper, by attacking the great and dreaded baboon. Such

actions as the above appear to be the simple result of the greater strength of the social or maternal instincts

rather than that of any other instinct or motive; for they are performed too instantaneously for reflection, or

for pleasure or pain to be felt at the time; though, if prevented by any cause, distress or even misery might be

felt. In a timid man, on the other hand, the instinct of selfpreservation might be so strong, that he would be

unable to force himself to run any such risk, perhaps not even for his own child.

I am aware that some persons maintain that actions performed impulsively, as in the above cases, do not

come under the dominion of the moral sense, and cannot be called moral. They confine this term to actions

done deliberately, after a victory over opposing desires, or when prompted by some exalted motive. But it

appears scarcely possible to draw any clear line of distinction of this kind. (25. I refer here to the distinction

between what has been called MATERIAL and FORMAL morality. I am glad to find that Professor Huxley

('Critiques and Addresses,' 1873, p. 287) takes the same view on this subject as I do. Mr. Leslie Stephen

remarks ('Essays on Freethinking and Plain Speaking,' 1873, p. 83), "the metaphysical distinction, between

material and formal morality is as irrelevant as other such distinctions.") As far as exalted motives are

concerned, many instances have been recorded of savages, destitute of any feeling of general benevolence

towards mankind, and not guided by any religious motive, who have deliberately sacrificed their lives as

prisoners(26. I have given one such case, namely of three Patagonian Indians who preferred being shot, one

after the other, to betraying the plans of their companions in war ('Journal of Researches,' 1845, p. 103).),

rather than betray their comrades; and surely their conduct ought to be considered as moral. As far as

deliberation, and the victory over opposing motives are concerned, animals may be seen doubting between

opposed instincts, in rescuing their offspring or comrades from danger; yet their actions, though done for the

good of others, are not called moral. Moreover, anything performed very often by us, will at last be done

without deliberation or hesitation, and can then hardly be distinguished from an instinct; yet surely no one

will pretend that such an action ceases to be moral. On the contrary, we all feel that an act cannot be

considered as perfect, or as performed in the most noble manner, unless it be done impulsively, without

deliberation or effort, in the same manner as by a man in whom the requisite qualities are innate. He who is

forced to overcome his fear or want of sympathy before he acts, deserves, however, in one way higher credit

than the man whose innate disposition leads him to a good act without effort. As we cannot distinguish

between motives, we rank all actions of a certain class as moral, if performed by a moral being. A moral

being is one who is capable of comparing his past and future actions or motives, and of approving or

disapproving of them. We have no reason to suppose that any of the lower animals have this capacity;

therefore, when a Newfoundland dog drags a child out of the water, or a monkey faces danger to rescue its

comrade, or takes charge of an orphan monkey, we do not call its conduct moral. But in the case of man, who

alone can with certainty be ranked as a moral being, actions of a certain class are called moral, whether

performed deliberately, after a struggle with opposing motives, or impulsively through instinct, or from the

But to return to our more immediate subject. Although some instincts are more powerful than others, and thus

lead to corresponding actions, yet it is untenable, that in man the social instincts (including the love of praise

and fear of blame) possess greater strength, or have, through long habit, acquired greater strength than the

instincts of selfpreservation, hunger, lust, vengeance, etc. Why then does man regret, even though trying to

banish such regret, that he has followed the one natural impulse rather than the other; and why does he further

feel that he ought to regret his conduct? Man in this respect differs profoundly from the lower animals.

Nevertheless we can, I think, see with some degree of clearness the reason of this difference.

Man, from the activity of his mental faculties, cannot avoid reflection: past impressions and images are

incessantly and clearly passing through his mind. Now with those animals which live permanently in a body,

the social instincts are ever present and persistent. Such animals are always ready to utter the dangersignal,

to defend the community, and to give aid to their fellows in accordance with their habits; they feel at all

times, without the stimulus of any special passion or desire, some degree of love and sympathy for them; they

are unhappy if long separated from them, and always happy to be again in their company. So it is with

ourselves. Even when we are quite alone, how often do we think with pleasure or pain of what others think of

us,of their imagined approbation or disapprobation; and this all follows from sympathy, a fundamental

element of the social instincts. A man who possessed no trace of such instincts would be an unnatural

monster. On the other hand, the desire to satisfy hunger, or any passion such as vengeance, is in its nature

temporary, and can for a time be fully satisfied. Nor is it easy, perhaps hardly possible, to call up with

complete vividness the feeling, for instance, of hunger; nor indeed, as has often been remarked, of any

suffering. The instinct of self preservation is not felt except in the presence of danger; and many a coward

has thought himself brave until he has met his enemy face to face. The wish for another man's property is

perhaps as persistent a desire as any that can be named; but even in this case the satisfaction of actual

possession is generally a weaker feeling than the desire: many a thief, if not a habitual one, after success has

wondered why he stole some article. (27. Enmity or hatred seems also to be a highly persistent feeling,

perhaps more so than any other that can be named. Envy is defined as hatred of another for some excellence

or success; and Bacon insists (Essay ix.), "Of all other affections envy is the most importune and continual."

Dogs are very apt to hate both strange men and strange dogs, especially if they live near at hand, but do not

belong to the same family, tribe, or clan; this feeling would thus seem to be innate, and is certainly a most

persistent one. It seems to be the complement and converse of the true social instinct. From what we hear of

savages, it would appear that something of the same kind holds good with them. If this be so, it would be a

small step in any one to transfer such feelings to any member of the same tribe if he had done him an injury

and had become his enemy. Nor is it probable that the primitive conscience would reproach a man for

injuring his enemy; rather it would reproach him, if he had not revenged himself. To do good in return for

evil, to love your enemy, is a height of morality to which it may be doubted whether the social instincts

would, by themselves, have ever led us. It is necessary that these instincts, together with sympathy, should

have been highly cultivated and extended by the aid of reason, instruction, and the love or fear of God, before

A man cannot prevent past impressions often repassing through his mind; he will thus be driven to make a

comparison between the impressions of past hunger, vengeance satisfied, or danger shunned at other men's

cost, with the almost everpresent instinct of sympathy, and with his early knowledge of what others consider

as praiseworthy or blameable. This knowledge cannot be banished from his mind, and from instinctive

sympathy is esteemed of great moment. He will then feel as if he had been baulked in following a present

instinct or habit, and this with all animals causes dissatisfaction, or even misery.

The above case of the swallow affords an illustration, though of a reversed nature, of a temporary though for

the time strongly persistent instinct conquering another instinct, which is usually dominant over all others. At

the proper season these birds seem all day long to be impressed with the desire to migrate; their habits

change; they become restless, are noisy and congregate in flocks. Whilst the motherbird is feeding, or

brooding over her nestlings, the maternal instinct is probably stronger than the migratory; but the instinct

which is the more persistent gains the victory, and at last, at a moment when her young ones are not in sight,

she takes flight and deserts them. When arrived at the end of her long journey, and the migratory instinct has

ceased to act, what an agony of remorse the bird would feel, if, from being endowed with great mental

activity, she could not prevent the image constantly passing through her mind, of her young ones perishing in

At the moment of action, man will no doubt be apt to follow the stronger impulse; and though this may

occasionally prompt him to the noblest deeds, it will more commonly lead him to gratify his own desires at

the expense of other men. But after their gratification when past and weaker impressions are judged by the

everenduring social instinct, and by his deep regard for the good opinion of his fellows, retribution will

surely come. He will then feel remorse, repentance, regret, or shame; this latter feeling, however, relates

almost exclusively to the judgment of others. He will consequently resolve more or less firmly to act

differently for the future; and this is conscience; for conscience looks backwards, and serves as a guide for

The nature and strength of the feelings which we call regret, shame, repentance or remorse, depend

apparently not only on the strength of the violated instinct, but partly on the strength of the temptation, and

often still more on the judgment of our fellows. How far each man values the appreciation of others, depends

on the strength of his innate or acquired feeling of sympathy; and on his own capacity for reasoning out the

remote consequences of his acts. Another element is most important, although not necessary, the reverence or

fear of the Gods, or Spirits believed in by each man: and this applies especially in cases of remorse. Several

critics have objected that though some slight regret or repentance may be explained by the view advocated in

this chapter, it is impossible thus to account for the soulshaking feeling of remorse. But I can see little force

in this objection. My critics do not define what they mean by remorse, and I can find no definition implying

more than an overwhelming sense of repentance. Remorse seems to bear the same relation to repentance, as

rage does to anger, or agony to pain. It is far from strange that an instinct so strong and so generally admired,

as maternal love, should, if disobeyed, lead to the deepest misery, as soon as the impression of the past cause

of disobedience is weakened. Even when an action is opposed to no special instinct, merely to know that our

friends and equals despise us for it is enough to cause great misery. Who can doubt that the refusal to fight a

duel through fear has caused many men an agony of shame? Many a Hindoo, it is said, has been stirred to the

bottom of his soul by having partaken of unclean food. Here is another case of what must, I think, be called

remorse. Dr. Landor acted as a magistrate in West Australia, and relates (28. 'Insanity in Relation to Law,'

Ontario, United States, 1871, p. 1.), that a native on his farm, after losing one of his wives from disease, came

and said that, "he was going to a distant tribe to spear a woman, to satisfy his sense of duty to his wife. I told

him that if he did so, I would send him to prison for life. He remained about the farm for some months, but

got exceedingly thin, and complained that he could not rest or eat, that his wife's spirit was haunting him,

because he had not taken a life for hers. I was inexorable, and assured him that nothing should save him if he

did." Nevertheless the man disappeared for more than a year, and then returned in high condition; and his

other wife told Dr. Landor that her husband had taken the life of a woman belonging to a distant tribe; but it

was impossible to obtain legal evidence of the act. The breach of a rule held sacred by the tribe, will thus, as

it seems, give rise to the deepest feelings,and this quite apart from the social instincts, excepting in so far

as the rule is grounded on the judgment of the community. How so many strange superstitions have arisen

throughout the world we know not; nor can we tell how some real and great crimes, such as incest, have

come to be held in an abhorrence (which is not however quite universal) by the lowest savages. It is even

doubtful whether in some tribes incest would be looked on with greater horror, than would the marriage of a

man with a woman bearing the same name, though not a relation. "To violate this law is a crime which the

Australians hold in the greatest abhorrence, in this agreeing exactly with certain tribes of North America.

When the question is put in either district, is it worse to kill a girl of a foreign tribe, or to marry a girl of one's

own, an answer just opposite to ours would be given without hesitation." (29. E.B. Tylor, in 'Contemporary

Review,' April 1873, p. 707.) We may, therefore, reject the belief, lately insisted on by some writers, that the

abhorrence of incest is due to our possessing a special Godimplanted conscience. On the whole it is

intelligible, that a man urged by so powerful a sentiment as remorse, though arising as above explained,

should be led to act in a manner, which he has been taught to believe serves as an expiation, such as

Man prompted by his conscience, will through long habit acquire such perfect selfcommand, that his desires

and passions will at last yield instantly and without a struggle to his social sympathies and instincts, including

his feeling for the judgment of his fellows. The still hungry, or the still revengeful man will not think of

stealing food, or of wreaking his vengeance. It is possible, or as we shall hereafter see, even probable, that the

habit of selfcommand may, like other habits, be inherited. Thus at last man comes to feel, through acquired

and perhaps inherited habit, that it is best for him to obey his more persistent impulses. The imperious word

"ought" seems merely to imply the consciousness of the existence of a rule of conduct, however it may have

originated. Formerly it must have been often vehemently urged that an insulted gentleman OUGHT to fight a

duel. We even say that a pointer OUGHT to point, and a retriever to retrieve game. If they fail to do so, they

If any desire or instinct leading to an action opposed to the good of others still appears, when recalled to

mind, as strong as, or stronger than, the social instinct, a man will feel no keen regret at having followed it;

but he will be conscious that if his conduct were known to his fellows, it would meet with their

disapprobation; and few are so destitute of sympathy as not to feel discomfort when this is realised. If he has

no such sympathy, and if his desires leading to bad actions are at the time strong, and when recalled are not

overmastered by the persistent social instincts, and the judgment of others, then he is essentially a bad man

(30. Dr. Prosper Despine, in his Psychologie Naturelle, 1868 (tom. i. p. 243; tom. ii. p. 169) gives many

curious cases of the worst criminals, who apparently have been entirely destitute of conscience.); and the sole

restraining motive left is the fear of punishment, and the conviction that in the long run it would be best for

It is obvious that every one may with an easy conscience gratify his own desires, if they do not interfere with

his social instincts, that is with the good of others; but in order to be quite free from selfreproach, or at least

of anxiety, it is almost necessary for him to avoid the disapprobation, whether reasonable or not, of his

fellowmen. Nor must he break through the fixed habits of his life, especially if these are supported by

reason; for if he does, he will assuredly feel dissatisfaction. He must likewise avoid the reprobation of the one

God or gods in whom, according to his knowledge or superstition, he may believe; but in this case the

The above view of the origin and nature of the moral sense, which tells us what we ought to do, and of the

conscience which reproves us if we disobey it, accords well with what we see of the early and undeveloped

condition of this faculty in mankind. The virtues which must be practised, at least generally, by rude men, so

that they may associate in a body, are those which are still recognised as the most important. But they are

practised almost exclusively in relation to the men of the same tribe; and their opposites are not regarded as

crimes in relation to the men of other tribes. No tribe could hold together if murder, robbery, treachery, etc.,

were common; consequently such crimes within the limits of the same tribe "are branded with everlasting

infamy" (31. See an able article in the 'North British Review,' 1867, p. 395. See also Mr. W. Bagehot's

articles on the Importance of Obedience and Coherence to Primitive Man, in the 'Fortnightly Review,' 1867,

p. 529, and 1868, p. 457, etc.); but excite no such sentiment beyond these limits. A NorthAmerican Indian is

well pleased with himself, and is honoured by others, when he scalps a man of another tribe; and a Dyak cuts

off the head of an unoffending person, and dries it as a trophy. The murder of infants has prevailed on the

largest scale throughout the world (32. The fullest account which I have met with is by Dr. Gerland, in his

'Ueber den Aussterben der Naturvolker,' 1868; but I shall have to recur to the subject of infanticide in a future

chapter.), and has met with no reproach; but infanticide, especially of females, has been thought to be good

for the tribe, or at least not injurious. Suicide during former times was not generally considered as a crime

(33. See the very interesting discussion on suicide in Lecky's 'History of European Morals,' vol. i. 1869, p.

223. With respect to savages, Mr. Winwood Reade informs me that the negroes of West Africa often commit

suicide. It is well known how common it was amongst the miserable aborigines of South America after the

Spanish conquest. For New Zealand, see the voyage of the "Novara," and for the Aleutian Islands, Muller, as

quoted by Houzeau, 'Les Facultes Mentales,' etc., tom. ii. p. 136.), but rather, from the courage displayed, as

an honourable act; and it is still practised by some semi civilised and savage nations without reproach, for it

does not obviously concern others of the tribe. It has been recorded that an Indian Thug conscientiously

regretted that he had not robbed and strangled as many travellers as did his father before him. In a rude state

of civilisation the robbery of strangers is, indeed, generally considered as honourable.

Slavery, although in some ways beneficial during ancient times (34. See Mr. Bagehot, 'Physics and Politics,'

1872, p. 72.), is a great crime; yet it was not so regarded until quite recently, even by the most civilised

nations. And this was especially the case, because the slaves belonged in general to a race different from that

of their masters. As barbarians do not regard the opinion of their women, wives are commonly treated like

slaves. Most savages are utterly indifferent to the sufferings of strangers, or even delight in witnessing them.

It is well known that the women and children of the NorthAmerican Indians aided in torturing their enemies.

Some savages take a horrid pleasure in cruelty to animals (35. See, for instance, Mr. Hamilton's account of

the Kaffirs, 'Anthropological Review,' 1870, p. xv.), and humanity is an unknown virtue. Nevertheless,

besides the family affections, kindness is common, especially during sickness, between the members of the

same tribe, and is sometimes extended beyond these limits. Mungo Park's touching account of the kindness of

the negro women of the interior to him is well known. Many instances could be given of the noble fidelity of

savages towards each other, but not to strangers; common experience justifies the maxim of the Spaniard,

"Never, never trust an Indian." There cannot be fidelity without truth; and this fundamental virtue is not rare

between the members of the same tribe: thus Mungo Park heard the negro women teaching their young

children to love the truth. This, again, is one of the virtues which becomes so deeply rooted in the mind, that

it is sometimes practised by savages, even at a high cost, towards strangers; but to lie to your enemy has

rarely been thought a sin, as the history of modern diplomacy too plainly shews. As soon as a tribe has a

recognised leader, disobedience becomes a crime, and even abject submission is looked at as a sacred virtue.

As during rude times no man can be useful or faithful to his tribe without courage, this quality has universally

been placed in the highest rank; and although in civilised countries a good yet timid man may be far more

useful to the community than a brave one, we cannot help instinctively honouring the latter above a coward,

however benevolent. Prudence, on the other hand, which does not concern the welfare of others, though a

very useful virtue, has never been highly esteemed. As no man can practise the virtues necessary for the

welfare of his tribe without selfsacrifice, self command, and the power of endurance, these qualities have

been at all times highly and most justly valued. The American savage voluntarily submits to the most horrid

tortures without a groan, to prove and strengthen his fortitude and courage; and we cannot help admiring him,

or even an Indian Fakir, who, from a foolish religious motive, swings suspended by a hook buried in his

The other socalled selfregarding virtues, which do not obviously, though they may really, affect the

welfare of the tribe, have never been esteemed by savages, though now highly appreciated by civilised

nations. The greatest intemperance is no reproach with savages. Utter licentiousness, and unnatural crimes,

prevail to an astounding extent. (36. Mr. M'Lennan has given ('Primitive Marriage,' 1865, p. 176) a good

collection of facts on this head.) As soon, however, as marriage, whether polygamous, or monogamous,

becomes common, jealousy will lead to the inculcation of female virtue; and this, being honoured, will tend

to spread to the unmarried females. How slowly it spreads to the male sex, we see at the present day. Chastity

eminently requires selfcommand; therefore it has been honoured from a very early period in the moral

history of civilised man. As a consequence of this, the senseless practice of celibacy has been ranked from a

remote period as a virtue. (38. Lecky, 'History of European Morals,' vol. i. 1869, p. 109.) The hatred of

indecency, which appears to us so natural as to be thought innate, and which is so valuable an aid to chastity,

is a modern virtue, appertaining exclusively, as Sir G. Staunton remarks (38. 'Embassy to China,' vol. ii. p.

348.), to civilised life. This is shewn by the ancient religious rites of various nations, by the drawings on the

We have now seen that actions are regarded by savages, and were probably so regarded by primeval man, as

good or bad, solely as they obviously affect the welfare of the tribe,not that of the species, nor that of an

individual member of the tribe. This conclusion agrees well with the belief that the socalled moral sense is

aboriginally derived from the social instincts, for both relate at first exclusively to the community.

The chief causes of the low morality of savages, as judged by our standard, are, firstly, the confinement of

sympathy to the same tribe. Secondly, powers of reasoning insufficient to recognise the bearing of many

virtues, especially of the selfregarding virtues, on the general welfare of the tribe. Savages, for instance, fail

to trace the multiplied evils consequent on a want of temperance, chastity, etc. And, thirdly, weak power of

selfcommand; for this power has not been strengthened through longcontinued, perhaps inherited, habit,

I have entered into the above details on the immorality of savages (39. See on this subject copious evidence

in Chap. vii. of Sir J. Lubbock, 'Origin of Civilisation,' 1870.), because some authors have recently taken a

high view of their moral nature, or have attributed most of their crimes to mistaken benevolence. (40. For

instance Lecky, 'History of European Morals,' vol. i. p. 124.) These authors appear to rest their conclusion on

savages possessing those virtues which are serviceable, or even necessary, for the existence of the family and

of the tribe,qualities which they undoubtedly do possess, and often in a high degree.

It was assumed formerly by philosophers of the derivative (41. This term is used in an able article in the

'Westminster Review,' Oct. 1869, p. 498. For the "Greatest happiness principle," see J.S. Mill,

'Utilitarianism,' p. 17.) school of morals that the foundation of morality lay in a form of Selfishness; but more

recently the "Greatest happiness principle" has been brought prominently forward. It is, however, more

correct to speak of the latter principle as the standard, and not as the motive of conduct. Nevertheless, all the

authors whose works I have consulted, with a few exceptions (42. Mill recognises ('System of Logic,' vol. ii.

p. 422) in the clearest manner, that actions may be performed through habit without the anticipation of

pleasure. Mr. H. Sidgwick also, in his Essay on Pleasure and Desire ('The Contemporary Review,' April

1872, p. 671), remarks: "To sum up, in contravention of the doctrine that our conscious active impulses are

always directed towards the production of agreeable sensations in ourselves, I would maintain that we find

everywhere in consciousness extraregarding impulse, directed towards something that is not pleasure; that

in many cases the impulse is so far incompatible with the selfregarding that the two do not easily coexist in

the same moment of consciousness." A dim feeling that our impulses do not by any means always arise from

any contemporaneous or anticipated pleasure, has, I cannot but think, been one chief cause of the acceptance

of the intuitive theory of morality, and of the rejection of the utilitarian or "Greatest happiness" theory. With

respect to the latter theory the standard and the motive of conduct have no doubt often been confused, but

they are really in some degree blended.), write as if there must be a distinct motive for every action, and that

this must be associated with some pleasure or displeasure. But man seems often to act impulsively, that is

from instinct or long habit, without any consciousness of pleasure, in the same manner as does probably a bee

or ant, when it blindly follows its instincts. Under circumstances of extreme peril, as during a fire, when a

man endeavours to save a fellowcreature without a moment's hesitation, he can hardly feel pleasure; and

still less has he time to reflect on the dissatisfaction which he might subsequently experience if he did not

make the attempt. Should he afterwards reflect over his own conduct, he would feel that there lies within him

an impulsive power widely different from a search after pleasure or happiness; and this seems to be the

In the case of the lower animals it seems much more appropriate to speak of their social instincts, as having

been developed for the general good rather than for the general happiness of the species. The term, general

good, may be defined as the rearing of the greatest number of individuals in full vigour and health, with all

their faculties perfect, under the conditions to which they are subjected. As the social instincts both of man

and the lower animals have no doubt been developed by nearly the same steps, it would be advisable, if found

practicable, to use the same definition in both cases, and to take as the standard of morality, the general good

or welfare of the community, rather than the general happiness; but this definition would perhaps require

When a man risks his life to save that of a fellowcreature, it seems also more correct to say that he acts for

the general good, rather than for the general happiness of mankind. No doubt the welfare and the happiness of

the individual usually coincide; and a contented, happy tribe will flourish better than one that is discontented

and unhappy. We have seen that even at an early period in the history of man, the expressed wishes of the

community will have naturally influenced to a large extent the conduct of each member; and as all wish for

happiness, the "greatest happiness principle" will have become a most important secondary guide and object;

the social instinct, however, together with sympathy (which leads to our regarding the approbation and

disapprobation of others), having served as the primary impulse and guide. Thus the reproach is removed of

laying the foundation of the noblest part of our nature in the base principle of selfishness; unless, indeed, the

satisfaction which every animal feels, when it follows its proper instincts, and the dissatisfaction felt when

The wishes and opinions of the members of the same community, expressed at first orally, but later by

writing also, either form the sole guides of our conduct, or greatly reinforce the social instincts; such

opinions, however, have sometimes a tendency directly opposed to these instincts. This latter fact is well

exemplified by the LAW OF HONOUR, that is, the law of the opinion of our equals, and not of all our

countrymen. The breach of this law, even when the breach is known to be strictly accordant with true

morality, has caused many a man more agony than a real crime. We recognise the same influence in the

burning sense of shame which most of us have felt, even after the interval of years, when calling to mind

some accidental breach of a trifling, though fixed, rule of etiquette. The judgment of the community will

generally be guided by some rude experience of what is best in the long run for all the members; but this

judgment will not rarely err from ignorance and weak powers of reasoning. Hence the strangest customs and

superstitions, in complete opposition to the true welfare and happiness of mankind, have become

allpowerful throughout the world. We see this in the horror felt by a Hindoo who breaks his caste, and in

many other such cases. It would be difficult to distinguish between the remorse felt by a Hindoo who has

yielded to the temptation of eating unclean food, from that felt after committing a theft; but the former would

How so many absurd rules of conduct, as well as so many absurd religious beliefs, have originated, we do not

know; nor how it is that they have become, in all quarters of the world, so deeply impressed on the mind of

men; but it is worthy of remark that a belief constantly inculcated during the early years of life, whilst the

brain is impressible, appears to acquire almost the nature of an instinct; and the very essence of an instinct is

that it is followed independently of reason. Neither can we say why certain admirable virtues, such as the

love of truth, are much more highly appreciated by some savage tribes than by others (43. Good instances are

given by Mr. Wallace in 'Scientific Opinion,' Sept. 15, 1869; and more fully in his 'Contributions to the

Theory of Natural Selection,' 1870, p. 353.); nor, again, why similar differences prevail even amongst highly

civilised nations. Knowing how firmly fixed many strange customs and superstitions have become, we need

feel no surprise that the self regarding virtues, supported as they are by reason, should now appear to us so

natural as to be thought innate, although they were not valued by man in his early condition.

Not withstanding many sources of doubt, man can generally and readily distinguish between the higher and

lower moral rules. The higher are founded on the social instincts, and relate to the welfare of others. They are

supported by the approbation of our fellowmen and by reason. The lower rules, though some of them when

implying selfsacrifice hardly deserve to be called lower, relate chiefly to self, and arise from public opinion,

matured by experience and cultivation; for they are not practised by rude tribes.

As man advances in civilisation, and small tribes are united into larger communities, the simplest reason

would tell each individual that he ought to extend his social instincts and sympathies to all the members of

the same nation, though personally unknown to him. This point being once reached, there is only an artificial

barrier to prevent his sympathies extending to the men of all nations and races. If, indeed, such men are

separated from him by great differences in appearance or habits, experience unfortunately shews us how long

it is, before we look at them as our fellowcreatures. Sympathy beyond the confines of man, that is, humanity

to the lower animals, seems to be one of the latest moral acquisitions. It is apparently unfelt by savages,

except towards their pets. How little the old Romans knew of it is shewn by their abhorrent gladiatorial

exhibitions. The very idea of humanity, as far as I could observe, was new to most of the Gauchos of the

Pampas. This virtue, one of the noblest with which man is endowed, seems to arise incidentally from our

sympathies becoming more tender and more widely diffused, until they are extended to all sentient beings. As

soon as this virtue is honoured and practised by some few men, it spreads through instruction and example to

The highest possible stage in moral culture is when we recognise that we ought to control our thoughts, and

"not even in inmost thought to think again the sins that made the past so pleasant to us." (44. Tennyson, Idylls

of the King, p. 244.) Whatever makes any bad action familiar to the mind, renders its performance by so

much the easier. As Marcus Aurelius long ago said, "Such as are thy habitual thoughts, such also will be the

character of thy mind; for the soul is dyed by the thoughts." (45. 'The Thoughts of the Emperor M. Aurelius

Antoninus,' English translation, 2nd edit., 1869. p. 112. Marcus Aurelius ws born A.D. 121.)

Our great philosopher, Herbert Spencer, has recently explained his views on the moral sense. He says (46.

Letter to Mr. Mill in Bain's 'Mental and Moral Science,' 1868, p. 722.), "I believe that the experiences of

utility organised and consolidated through all past generations of the human race, have been producing

corresponding modifications, which, by continued transmission and accumulation, have become in us certain

faculties of moral intuitioncertain emotions responding to right and wrong conduct, which have no

apparent basis in the individual experiences of utility." There is not the least inherent improbability, as it

seems to me, in virtuous tendencies being more or less strongly inherited; for, not to mention the various

dispositions and habits transmitted by many of our domestic animals to their offspring, I have heard of

authentic cases in which a desire to steal and a tendency to lie appeared to run in families of the upper ranks;

and as stealing is a rare crime in the wealthy classes, we can hardly account by accidental coincidence for the

tendency occurring in two or three members of the same family. If bad tendencies are transmitted, it is

probable that good ones are likewise transmitted. That the state of the body by affecting the brain, has great

influence on the moral tendencies is known to most of those who have suffered from chronic derangements of

the digestion or liver. The same fact is likewise shewn by the "perversion or destruction of the moral sense

being often one of the earliest symptoms of mental derangement" (47. Maudsley, 'Body and Mind,' 1870, p.

60.); and insanity is notoriously often inherited. Except through the principle of the transmission of moral

tendencies, we cannot understand the differences believed to exist in this respect between the various races of

Even the partial transmission of virtuous tendencies would be an immense assistance to the primary impulse

derived directly and indirectly from the social instincts. Admitting for a moment that virtuous tendencies are

inherited, it appears probable, at least in such cases as chastity, temperance, humanity to animals, etc., that

they become first impressed on the mental organization through habit, instruction and example, continued

during several generations in the same family, and in a quite subordinate degree, or not at all, by the

individuals possessing such virtues having succeeded best in the struggle for life. My chief source of doubt

with respect to any such inheritance, is that senseless customs, superstitions, and tastes, such as the horror of

a Hindoo for unclean food, ought on the same principle to be transmitted. I have not met with any evidence in

support of the transmission of superstitious customs or senseless habits, although in itself it is perhaps not

less probable than that animals should acquire inherited tastes for certain kinds of food or fear of certain foes.

Finally the social instincts, which no doubt were acquired by man as by the lower animals for the good of the

community, will from the first have given to him some wish to aid his fellows, some feeling of sympathy, and

have compelled him to regard their approbation and disapprobation. Such impulses will have served him at a

very early period as a rude rule of right and wrong. But as man gradually advanced in intellectual power, and

was enabled to trace the more remote consequences of his actions; as he acquired sufficient knowledge to

reject baneful customs and superstitions; as he regarded more and more, not only the welfare, but the

happiness of his fellowmen; as from habit, following on beneficial experience, instruction and example, his

sympathies became more tender and widely diffused, extending to men of all races, to the imbecile, maimed,

and other useless members of society, and finally to the lower animals,so would the standard of his

morality rise higher and higher. And it is admitted by moralists of the derivative school and by some

intuitionists, that the standard of morality has risen since an early period in the history of man. (48. A writer

in the 'North British Review' (July 1869, p. 531), well capable of forming a sound judgment, expresses

himself strongly in favour of this conclusion. Mr. Lecky ('History of Morals,' vol. i. p. 143) seems to a certain

As a struggle may sometimes be seen going on between the various instincts of the lower animals, it is not

surprising that there should be a struggle in man between his social instincts, with their derived virtues, and

his lower, though momentarily stronger impulses or desires. This, as Mr. Galton (49. See his remarkable

work on 'Hereditary Genius,' 1869, p. 349. The Duke of Argyll ('Primeval Man,' 1869, p. 188) has some good

remarks on the contest in man's nature between right and wrong.) has remarked, is all the less surprising, as

man has emerged from a state of barbarism within a comparatively recent period. After having yielded to

some temptation we feel a sense of dissatisfaction, shame, repentance, or remorse, analogous to the feelings

caused by other powerful instincts or desires, when left unsatisfied or baulked. We compare the weakened

impression of a past temptation with the ever present social instincts, or with habits, gained in early youth and

strengthened during our whole lives, until they have become almost as strong as instincts. If with the

temptation still before us we do not yield, it is because either the social instinct or some custom is at the

moment predominant, or because we have learnt that it will appear to us hereafter the stronger, when

compared with the weakened impression of the temptation, and we realise that its violation would cause us

suffering. Looking to future generations, there is no cause to fear that the social instincts will grow weaker,

and we may expect that virtuous habits will grow stronger, becoming perhaps fixed by inheritance. In this

case the struggle between our higher and lower impulses will be less severe, and virtue will be triumphant.

There can be no doubt that the difference between the mind of the lowest man and that of the highest animal

is immense. An anthropomorphous ape, if he could take a dispassionate view of his own case, would admit

that though he could form an artful plan to plunder a gardenthough he could use stones for fighting or for

breaking open nuts, yet that the thought of fashioning a stone into a tool was quite beyond his scope. Still

less, as he would admit, could he follow out a train of metaphysical reasoning, or solve a mathematical

problem, or reflect on God, or admire a grand natural scene. Some apes, however, would probably declare

that they could and did admire the beauty of the coloured skin and fur of their partners in marriage. They

would admit, that though they could make other apes understand by cries some of their perceptions and

simpler wants, the notion of expressing definite ideas by definite sounds had never crossed their minds. They

might insist that they were ready to aid their fellowapes of the same troop in many ways, to risk their lives

for them, and to take charge of their orphans; but they would be forced to acknowledge that disinterested love

for all living creatures, the most noble attribute of man, was quite beyond their comprehension.

Nevertheless the difference in mind between man and the higher animals, great as it is, certainly is one of

degree and not of kind. We have seen that the senses and intuitions, the various emotions and faculties, such

as love, memory, attention, curiosity, imitation, reason, etc., of which man boasts, may be found in an

incipient, or even sometimes in a welldeveloped condition, in the lower animals. They are also capable of

some inherited improvement, as we see in the domestic dog compared with the wolf or jackal. If it could be

proved that certain high mental powers, such as the formation of general concepts, selfconsciousness, etc.,

were absolutely peculiar to man, which seems extremely doubtful, it is not improbable that these qualities are

merely the incidental results of other highlyadvanced intellectual faculties; and these again mainly the result

of the continued use of a perfect language. At what age does the newborn infant possess the power of

abstraction, or become selfconscious, and reflect on its own existence? We cannot answer; nor can we

answer in regard to the ascending organic scale. The halfart, halfinstinct of language still bears the stamp

of its gradual evolution. The ennobling belief in God is not universal with man; and the belief in spiritual

agencies naturally follows from other mental powers. The moral sense perhaps affords the best and highest

distinction between man and the lower animals; but I need say nothing on this head, as I have so lately

endeavoured to shew that the social instincts,the prime principle of man's moral constitution (50. 'The

Thoughts of Marcus Aurelius,' etc., p. 139.)with the aid of active intellectual powers and the effects of

habit, naturally lead to the golden rule, "As ye would that men should do to you, do ye to them likewise;" and

In the next chapter I shall make some few remarks on the probable steps and means by which the several

mental and moral faculties of man have been gradually evolved. That such evolution is at least possible,

ought not to be denied, for we daily see these faculties developing in every infant; and we may trace a perfect

gradation from the mind of an utter idiot, lower than that of an animal low in the scale, to the mind of a

Advancement of the intellectual powers through natural selection Importance of imitationSocial and

moral facultiesTheir development within the limits of the same tribeNatural selection as affecting

The subjects to be discussed in this chapter are of the highest interest, but are treated by me in an imperfect

and fragmentary manner. Mr. Wallace, in an admirable paper before referred to (1. Anthropological Review,

May 1864, p. clviii.), argues that man, after he had partially acquired those intellectual and moral faculties

which distinguish him from the lower animals, would have been but little liable to bodily modifications

through natural selection or any other means. For man is enabled through his mental faculties "to keep with

an unchanged body in harmony with the changing universe." He has great power of adapting his habits to

new conditions of life. He invents weapons, tools, and various stratagems to procure food and to defend

himself. When he migrates into a colder climate he uses clothes, builds sheds, and makes fires; and by the aid

of fire cooks food otherwise indigestible. He aids his fellowmen in many ways, and anticipates future

The lower animals, on the other hand, must have their bodily structure modified in order to survive under

greatly changed conditions. They must be rendered stronger, or acquire more effective teeth or claws, for

defence against new enemies; or they must be reduced in size, so as to escape detection and danger. When

they migrate into a colder climate, they must become clothed with thicker fur, or have their constitutions

The case, however, is widely different, as Mr. Wallace has with justice insisted, in relation to the intellectual

and moral faculties of man. These faculties are variable; and we have every reason to believe that the

variations tend to be inherited. Therefore, if they were formerly of high importance to primeval man and to

his apelike progenitors, they would have been perfected or advanced through natural selection. Of the high

importance of the intellectual faculties there can be no doubt, for man mainly owes to them his predominant

position in the world. We can see, that in the rudest state of society, the individuals who were the most

sagacious, who invented and used the best weapons or traps, and who were best able to defend themselves,

would rear the greatest number of offspring. The tribes, which included the largest number of men thus

endowed, would increase in number and supplant other tribes. Numbers depend primarily on the means of

subsistence, and this depends partly on the physical nature of the country, but in a much higher degree on the

arts which are there practised. As a tribe increases and is victorious, it is often still further increased by the

absorption of other tribes. (2. After a time the members or tribes which are absorbed into another tribe

assume, as Sir Henry Maine remarks ('Ancient Law,' 1861, p. 131), that they are the codescendants of the

same ancestors.) The stature and strength of the men of a tribe are likewise of some importance for its

success, and these depend in part on the nature and amount of the food which can be obtained. In Europe the

men of the Bronze period were supplanted by a race more powerful, and, judging from their swordhandles,

with larger hands (3. Morlot, 'Soc. Vaud. Sc. Nat.' 1860, p. 294.); but their success was probably still more

All that we know about savages, or may infer from their traditions and from old monuments, the history of

which is quite forgotten by the present inhabitants, shew that from the remotest times successful tribes have

supplanted other tribes. Relics of extinct or forgotten tribes have been discovered throughout the civilised

regions of the earth, on the wild plains of America, and on the isolated islands in the Pacific Ocean. At the

present day civilised nations are everywhere supplanting barbarous nations, excepting where the climate

opposes a deadly barrier; and they succeed mainly, though not exclusively, through their arts, which are the

products of the intellect. It is, therefore, highly probable that with mankind the intellectual faculties have been

mainly and gradually perfected through natural selection; and this conclusion is sufficient for our purpose.

Undoubtedly it would be interesting to trace the development of each separate faculty from the state in which

it exists in the lower animals to that in which it exists in man; but neither my ability nor knowledge permits

It deserves notice that, as soon as the progenitors of man became social (and this probably occurred at a very

early period), the principle of imitation, and reason, and experience would have increased, and much

modified the intellectual powers in a way, of which we see only traces in the lower animals. Apes are much

given to imitation, as are the lowest savages; and the simple fact previously referred to, that after a time no

animal can be caught in the same place by the same sort of trap, shews that animals learn by experience, and

imitate the caution of others. Now, if some one man in a tribe, more sagacious than the others, invented a new

snare or weapon, or other means of attack or defence, the plainest self interest, without the assistance of

much reasoning power, would prompt the other members to imitate him; and all would thus profit. The

habitual practice of each new art must likewise in some slight degree strengthen the intellect. If the new

invention were an important one, the tribe would increase in number, spread, and supplant other tribes. In a

tribe thus rendered more numerous there would always be a rather greater chance of the birth of other

superior and inventive members. If such men left children to inherit their mental superiority, the chance of the

birth of still more ingenious members would be somewhat better, and in a very small tribe decidedly better.

Even if they left no children, the tribe would still include their bloodrelations; and it has been ascertained by

agriculturists (4. I have given instances in my Variation of Animals under Domestication, vol. ii. p. 196.) that

by preserving and breeding from the family of an animal, which when slaughtered was found to be valuable,

Turning now to the social and moral faculties. In order that primeval men, or the apelike progenitors of

man, should become social, they must have acquired the same instinctive feelings, which impel other animals

to live in a body; and they no doubt exhibited the same general disposition. They would have felt uneasy

when separated from their comrades, for whom they would have felt some degree of love; they would have

warned each other of danger, and have given mutual aid in attack or defence. All this implies some degree of

sympathy, fidelity, and courage. Such social qualities, the paramount importance of which to the lower

animals is disputed by no one, were no doubt acquired by the progenitors of man in a similar manner,

namely, through natural selection, aided by inherited habit. When two tribes of primeval man, living in the

same country, came into competition, if (other circumstances being equal) the one tribe included a great

number of courageous, sympathetic and faithful members, who were always ready to warn each other of

danger, to aid and defend each other, this tribe would succeed better and conquer the other. Let it be borne in

mind how all important in the neverceasing wars of savages, fidelity and courage must be. The advantage

which disciplined soldiers have over undisciplined hordes follows chiefly from the confidence which each

man feels in his comrades. Obedience, as Mr. Bagehot has well shewn (5. See a remarkable series of articles

on 'Physics and Politics,' in the 'Fortnightly Review,' Nov. 1867; April 1, 1868; July 1, 1869, since separately

published.), is of the highest value, for any form of government is better than none. Selfish and contentious

people will not cohere, and without coherence nothing can be effected. A tribe rich in the above qualities

would spread and be victorious over other tribes: but in the course of time it would, judging from all past

history, be in its turn overcome by some other tribe still more highly endowed. Thus the social and moral

But it may be asked, how within the limits of the same tribe did a large number of members first become

endowed with these social and moral qualities, and how was the standard of excellence raised? It is extremely

doubtful whether the offspring of the more sympathetic and benevolent parents, or of those who were the

most faithful to their comrades, would be reared in greater numbers than the children of selfish and

treacherous parents belonging to the same tribe. He who was ready to sacrifice his life, as many a savage has

been, rather than betray his comrades, would often leave no offspring to inherit his noble nature. The bravest

men, who were always willing to come to the front in war, and who freely risked their lives for others, would

on an average perish in larger numbers than other men. Therefore, it hardly seems probable, that the number

of men gifted with such virtues, or that the standard of their excellence, could be increased through natural

selection, that is, by the survival of the fittest; for we are not here speaking of one tribe being victorious over

Although the circumstances, leading to an increase in the number of those thus endowed within the same

tribe, are too complex to be clearly followed out, we can trace some of the probable steps. In the first place,

as the reasoning powers and foresight of the members became improved, each man would soon learn that if

he aided his fellowmen, he would commonly receive aid in return. From this low motive he might acquire

the habit of aiding his fellows; and the habit of performing benevolent actions certainly strengthens the

feeling of sympathy which gives the first impulse to benevolent actions. Habits, moreover, followed during

But another and much more powerful stimulus to the development of the social virtues, is afforded by the

praise and the blame of our fellowmen. To the instinct of sympathy, as we have already seen, it is primarily

due, that we habitually bestow both praise and blame on others, whilst we love the former and dread the latter

when applied to ourselves; and this instinct no doubt was originally acquired, like all the other social

instincts, through natural selection. At how early a period the progenitors of man in the course of their

development, became capable of feeling and being impelled by, the praise or blame of their fellow

creatures, we cannot of course say. But it appears that even dogs appreciate encouragement, praise, and

blame. The rudest savages feel the sentiment of glory, as they clearly shew by preserving the trophies of their

prowess, by their habit of excessive boasting, and even by the extreme care which they take of their personal

appearance and decorations; for unless they regarded the opinion of their comrades, such habits would be

They certainly feel shame at the breach of some of their lesser rules, and apparently remorse, as shewn by the

case of the Australian who grew thin and could not rest from having delayed to murder some other woman,

so as to propitiate his dead wife's spirit. Though I have not met with any other recorded case, it is scarcely

credible that a savage, who will sacrifice his life rather than betray his tribe, or one who will deliver himself

up as a prisoner rather than break his parole (6. Mr. Wallace gives cases in his 'Contributions to the Theory of

Natural Selection,' 1870, p. 354.), would not feel remorse in his inmost soul, if he had failed in a duty, which

We may therefore conclude that primeval man, at a very remote period, was influenced by the praise and

blame of his fellows. It is obvious, that the members of the same tribe would approve of conduct which

appeared to them to be for the general good, and would reprobate that which appeared evil. To do good unto

othersto do unto others as ye would they should do unto youis the foundationstone of morality. It is,

therefore, hardly possible to exaggerate the importance during rude times of the love of praise and the dread

of blame. A man who was not impelled by any deep, instinctive feeling, to sacrifice his life for the good of

others, yet was roused to such actions by a sense of glory, would by his example excite the same wish for

glory in other men, and would strengthen by exercise the noble feeling of admiration. He might thus do far

more good to his tribe than by begetting offspring with a tendency to inherit his own high character.

With increased experience and reason, man perceives the more remote consequences of his actions, and the

selfregarding virtues, such as temperance, chastity, etc., which during early times are, as we have before

seen, utterly disregarded, come to be highly esteemed or even held sacred. I need not, however, repeat what I

have said on this head in the fourth chapter. Ultimately our moral sense or conscience becomes a highly

complex sentimentoriginating in the social instincts, largely guided by the approbation of our fellowmen,

ruled by reason, selfinterest, and in later times by deep religious feelings, and confirmed by instruction and

It must not be forgotten that although a high standard of morality gives but a slight or no advantage to each

individual man and his children over the other men of the same tribe, yet that an increase in the number of

wellendowed men and an advancement in the standard of morality will certainly give an immense

advantage to one tribe over another. A tribe including many members who, from possessing in a high degree

the spirit of patriotism, fidelity, obedience, courage, and sympathy, were always ready to aid one another, and

to sacrifice themselves for the common good, would be victorious over most other tribes; and this would be

natural selection. At all times throughout the world tribes have supplanted other tribes; and as morality is one

important element in their success, the standard of morality and the number of wellendowed men will thus

It is, however, very difficult to form any judgment why one particular tribe and not another has been

successful and has risen in the scale of civilisation. Many savages are in the same condition as when first

discovered several centuries ago. As Mr. Bagehot has remarked, we are apt to look at progress as normal in

human society; but history refutes this. The ancients did not even entertain the idea, nor do the Oriental

nations at the present day. According to another high authority, Sir Henry Maine (7. 'Ancient Law,' 1861, p.

22. For Mr. Bagehot's remarks, 'Fortnightly Review,' April 1, 1868, p. 452.), "the greatest part of mankind

has never shewn a particle of desire that its civil institutions should be improved." Progress seems to depend

on many concurrent favourable conditions, far too complex to be followed out. But it has often been

remarked, that a cool climate, from leading to industry and to the various arts, has been highly favourable

thereto. The Esquimaux, pressed by hard necessity, have succeeded in many ingenious inventions, but their

climate has been too severe for continued progress. Nomadic habits, whether over wide plains, or through the

dense forests of the tropics, or along the shores of the sea, have in every case been highly detrimental. Whilst

observing the barbarous inhabitants of Tierra del Fuego, it struck me that the possession of some property, a

fixed abode, and the union of many families under a chief, were the indispensable requisites for civilisation.

Such habits almost necessitate the cultivation of the ground; and the first steps in cultivation would probably

result, as I have elsewhere shewn (8. 'The Variation of Animals and Plants under Domestication,' vol. i. p.

309.), from some such accident as the seeds of a fruittree falling on a heap of refuse, and producing an

unusually fine variety. The problem, however, of the first advance of savages towards civilisation is at

I have hitherto only considered the advancement of man from a semihuman condition to that of the modern

savage. But some remarks on the action of natural selection on civilised nations may be worth adding. This

subject has been ably discussed by Mr. W.R. Greg (9. 'Fraser's Magazine,' Sept. 1868, p. 353. This article

seems to have struck many persons, and has given rise to two remarkable essays and a rejoinder in the

'Spectator,' Oct. 3rd and 17th, 1868. It has also been discussed in the 'Quarterly Journal of Science,' 1869, p.

152, and by Mr. Lawson Tait in the 'Dublin Quarterly Journal of Medical Science,' Feb. 1869, and by Mr. E.

Ray Lankester in his 'Comparative Longevity,' 1870, p. 128. Similar views appeared previously in the

'Australasian,' July 13, 1867. I have borrowed ideas from several of these writers.), and previously by Mr.

Wallace and Mr. Galton. (10. For Mr. Wallace, see 'Anthropological Review,' as before cited. Mr. Galton in

'Macmillan's Magazine,' Aug. 1865, p. 318; also his great work, 'Hereditary Genius,' 1870.) Most of my

remarks are taken from these three authors. With savages, the weak in body or mind are soon eliminated; and

those that survive commonly exhibit a vigorous state of health. We civilised men, on the other hand, do our

utmost to check the process of elimination; we build asylums for the imbecile, the maimed, and the sick; we

institute poorlaws; and our medical men exert their utmost skill to save the life of every one to the last

moment. There is reason to believe that vaccination has preserved thousands, who from a weak constitution

would formerly have succumbed to smallpox. Thus the weak members of civilised societies propagate their

kind. No one who has attended to the breeding of domestic animals will doubt that this must be highly

injurious to the race of man. It is surprising how soon a want of care, or care wrongly directed, leads to the

degeneration of a domestic race; but excepting in the case of man himself, hardly any one is so ignorant as to

The aid which we feel impelled to give to the helpless is mainly an incidental result of the instinct of

sympathy, which was originally acquired as part of the social instincts, but subsequently rendered, in the

manner previously indicated, more tender and more widely diffused. Nor could we check our sympathy, even

at the urging of hard reason, without deterioration in the noblest part of our nature. The surgeon may harden

himself whilst performing an operation, for he knows that he is acting for the good of his patient; but if we

were intentionally to neglect the weak and helpless, it could only be for a contingent benefit, with an

overwhelming present evil. We must therefore bear the undoubtedly bad effects of the weak surviving and

propagating their kind; but there appears to be at least one check in steady action, namely that the weaker and

inferior members of society do not marry so freely as the sound; and this check might be indefinitely

increased by the weak in body or mind refraining from marriage, though this is more to be hoped for than

In every country in which a large standing army is kept up, the finest young men are taken by the

conscription or are enlisted. They are thus exposed to early death during war, are often tempted into vice, and

are prevented from marrying during the prime of life. On the other hand the shorter and feebler men, with

poor constitutions, are left at home, and consequently have a much better chance of marrying and propagating

their kind. (11. Prof. H. Fick ('Einfluss der Naturwissenschaft auf das Recht,' June 1872) has some good

Man accumulates property and bequeaths it to his children, so that the children of the rich have an advantage

over the poor in the race for success, independently of bodily or mental superiority. On the other hand, the

children of parents who are shortlived, and are therefore on an average deficient in health and vigour, come

into their property sooner than other children, and will be likely to marry earlier, and leave a larger number of

offspring to inherit their inferior constitutions. But the inheritance of property by itself is very far from an

evil; for without the accumulation of capital the arts could not progress; and it is chiefly through their power

that the civilised races have extended, and are now everywhere extending their range, so as to take the place

of the lower races. Nor does the moderate accumulation of wealth interfere with the process of selection.

When a poor man becomes moderately rich, his children enter trades or professions in which there is struggle

enough, so that the able in body and mind succeed best. The presence of a body of wellinstructed men, who

have not to labour for their daily bread, is important to a degree which cannot be overestimated; as all high

intellectual work is carried on by them, and on such work, material progress of all kinds mainly depends, not

to mention other and higher advantages. No doubt wealth when very great tends to convert men into useless

drones, but their number is never large; and some degree of elimination here occurs, for we daily see rich

Primogeniture with entailed estates is a more direct evil, though it may formerly have been a great advantage

by the creation of a dominant class, and any government is better than none. Most eldest sons, though they

may be weak in body or mind, marry, whilst the younger sons, however superior in these respects, do not so

generally marry. Nor can worthless eldest sons with entailed estates squander their wealth. But here, as

elsewhere, the relations of civilised life are so complex that some compensatory checks intervene. The men

who are rich through primogeniture are able to select generation after generation the more beautiful and

charming women; and these must generally be healthy in body and active in mind. The evil consequences,

such as they may be, of the continued preservation of the same line of descent, without any selection, are

checked by men of rank always wishing to increase their wealth and power; and this they effect by marrying

heiresses. But the daughters of parents who have produced single children, are themselves, as Mr. Galton (12.

'Hereditary Genius,' 1870, pp. 132140.) has shewn, apt to be sterile; and thus noble families are continually

cut off in the direct line, and their wealth flows into some side channel; but unfortunately this channel is not

Although civilisation thus checks in many ways the action of natural selection, it apparently favours the better

development of the body, by means of good food and the freedom from occasional hardships. This may be

inferred from civilised men having been found, wherever compared, to be physically stronger than savages.

(13. Quatrefages, 'Revue des Cours Scientifiques,' 186768, p. 659.) They appear also to have equal powers

of endurance, as has been proved in many adventurous expeditions. Even the great luxury of the rich can be

but little detrimental; for the expectation of life of our aristocracy, at all ages and of both sexes, is very little

inferior to that of healthy English lives in the lower classes. (14. See the fifth and sixth columns, compiled

from good authorities, in the table given in Mr. E.R. Lankester's 'Comparative Longevity,' 1870, p. 115.)

We will now look to the intellectual faculties. If in each grade of society the members were divided into two

equal bodies, the one including the intellectually superior and the other the inferior, there can be little doubt

that the former would succeed best in all occupations, and rear a greater number of children. Even in the

lowest walks of life, skill and ability must be of some advantage; though in many occupations, owing to the

great division of labour, a very small one. Hence in civilised nations there will be some tendency to an

increase both in the number and in the standard of the intellectually able. But I do not wish to assert that this

tendency may not be more than counterbalanced in other ways, as by the multiplication of the reckless and

It has often been objected to views like the foregoing, that the most eminent men who have ever lived have

left no offspring to inherit their great intellect. Mr. Galton says, "I regret I am unable to solve the simple

question whether, and how far, men and women who are prodigies of genius are infertile. I have, however,

shewn that men of eminence are by no means so." (15. 'Hereditary Genius,' 1870, p. 330.) Great lawgivers,

the founders of beneficent religions, great philosophers and discoverers in science, aid the progress of

mankind in a far higher degree by their works than by leaving a numerous progeny. In the case of corporeal

structures, it is the selection of the slightly betterendowed and the elimination of the slightly less

wellendowed individuals, and not the preservation of stronglymarked and rare anomalies, that leads to the

advancement of a species. (16. 'Origin of Species' (fifth edition, 1869), p. 104.) So it will be with the

intellectual faculties, since the somewhat abler men in each grade of society succeed rather better than the

less able, and consequently increase in number, if not otherwise prevented. When in any nation the standard

of intellect and the number of intellectual men have increased, we may expect from the law of the deviation

from an average, that prodigies of genius will, as shewn by Mr. Galton, appear somewhat more frequently

In regard to the moral qualities, some elimination of the worst dispositions is always in progress even in the

most civilised nations. Malefactors are executed, or imprisoned for long periods, so that they cannot freely

transmit their bad qualities. Melancholic and insane persons are confined, or commit suicide. Violent and

quarrelsome men often come to a bloody end. The restless who will not follow any steady occupationand

this relic of barbarism is a great check to civilisation (17. 'Hereditary Genius,' 1870, p. 347.)emigrate to

newlysettled countries; where they prove useful pioneers. Intemperance is so highly destructive, that the

expectation of life of the intemperate, at the age of thirty for instance, is only 13.8 years; whilst for the rural

labourers of England at the same age it is 40.59 years. (18. E. Ray Lankester, 'Comparative Longevity,' 1870,

p. 115. The table of the intemperate is from Neison's 'Vital Statistics.' In regard to profligacy, see Dr. Farr,

'Influence of Marriage on Mortality,' 'Nat. Assoc. for the Promotion of Social Science,' 1858.) Profligate

women bear few children, and profligate men rarely marry; both suffer from disease. In the breeding of

domestic animals, the elimination of those individuals, though few in number, which are in any marked

manner inferior, is by no means an unimportant element towards success. This especially holds good with

injurious characters which tend to reappear through reversion, such as blackness in sheep; and with mankind

some of the worst dispositions, which occasionally without any assignable cause make their appearance in

families, may perhaps be reversions to a savage state, from which we are not removed by very many

generations. This view seems indeed recognised in the common expression that such men are the black sheep

With civilised nations, as far as an advanced standard of morality, and an increased number of fairly good

men are concerned, natural selection apparently effects but little; though the fundamental social instincts were

originally thus gained. But I have already said enough, whilst treating of the lower races, on the causes which

lead to the advance of morality, namely, the approbation of our fellowmenthe strengthening of our

sympathies by habitexample and imitationreasonexperience, and even selfinterestinstruction

A most important obstacle in civilised countries to an increase in the number of men of a superior class has

been strongly insisted on by Mr. Greg and Mr. Galton (19. 'Fraser's Magazine,' Sept. 1868, p. 353.

'Macmillan's Magazine,' Aug. 1865, p. 318. The Rev. F.W. Farrar ('Fraser's Magazine,' Aug. 1870, p. 264)

takes a different view.), namely, the fact that the very poor and reckless, who are often degraded by vice,

almost invariably marry early, whilst the careful and frugal, who are generally otherwise virtuous, marry late

in life, so that they may be able to support themselves and their children in comfort. Those who marry early

produce within a given period not only a greater number of generations, but, as shewn by Dr. Duncan (20.

'On the Laws of the Fertility of Women,' in 'Transactions of the Royal Society,' Edinburgh, vol. xxiv. p. 287;

now published separately under the title of 'Fecundity, Fertility, and Sterility,' 1871. See, also, Mr. Galton,

'Hereditary Genius,' pp. 352357, for observations to the above effect.), they produce many more children.

The children, moreover, that are borne by mothers during the prime of life are heavier and larger, and

therefore probably more vigorous, than those born at other periods. Thus the reckless, degraded, and often

vicious members of society, tend to increase at a quicker rate than the provident and generally virtuous

members. Or as Mr. Greg puts the case: "The careless, squalid, unaspiring Irishman multiplies like rabbits:

the frugal, foreseeing, selfrespecting, ambitious Scot, stern in his morality, spiritual in his faith, sagacious

and disciplined in his intelligence, passes his best years in struggle and in celibacy, marries late, and leaves

few behind him. Given a land originally peopled by a thousand Saxons and a thousand Celtsand in a dozen

generations fivesixths of the population would be Celts, but five sixths of the property, of the power, of the

intellect, would belong to the onesixth of Saxons that remained. In the eternal 'struggle for existence,' it

would be the inferior and LESS favoured race that had prevailedand prevailed by virtue not of its good

There are, however, some checks to this downward tendency. We have seen that the intemperate suffer from

a high rate of mortality, and the extremely profligate leave few offspring. The poorest classes crowd into

towns, and it has been proved by Dr. Stark from the statistics of ten years in Scotland (21. 'Tenth Annual

Report of Births, Deaths, etc., in Scotland,' 1867, p. xxix.), that at all ages the deathrate is higher in towns

than in rural districts, "and during the first five years of life the town deathrate is almost exactly double that

of the rural districts." As these returns include both the rich and the poor, no doubt more than twice the

number of births would be requisite to keep up the number of the very poor inhabitants in the towns,

relatively to those in the country. With women, marriage at too early an age is highly injurious; for it has

been found in France that, "Twice as many wives under twenty die in the year, as died out of the same

number of the unmarried." The mortality, also, of husbands under twenty is "excessively high" (22. These

quotations are taken from our highest authority on such questions, namely, Dr. Farr, in his paper 'On the

Influence of Marriage on the Mortality of the French People,' read before the Nat. Assoc. for the Promotion

of Social Science, 1858.), but what the cause of this may be, seems doubtful. Lastly, if the men who

prudently delay marrying until they can bring up their families in comfort, were to select, as they often do,

women in the prime of life, the rate of increase in the better class would be only slightly lessened.

It was established from an enormous body of statistics, taken during 1853, that the unmarried men throughout

France, between the ages of twenty and eighty, die in a much larger proportion than the married: for instance,

out of every 1000 unmarried men, between the ages of twenty and thirty, 11.3 annually died, whilst of the

married, only 6.5 died. (23. Dr. Farr, ibid. The quotations given below are extracted from the same striking

paper.) A similar law was proved to hold good, during the years 1863 and 1864, with the entire population

above the age of twenty in Scotland: for instance, out of every 1000 unmarried men, between the ages of

twenty and thirty, 14.97 annually died, whilst of the married only 7.24 died, that is less than half. (24. I have

taken the mean of the quinquennial means, given in 'The Tenth Annual Report of Births, Deaths, etc., in

Scotland,' 1867. The quotation from Dr. Stark is copied from an article in the 'Daily News,' Oct. 17, 1868,

which Dr. Farr considers very carefully written.) Dr. Stark remarks on this, "Bachelorhood is more

destructive to life than the most unwholesome trades, or than residence in an unwholesome house or district

where there has never been the most distant attempt at sanitary improvement." He considers that the lessened

mortality is the direct result of "marriage, and the more regular domestic habits which attend that state." He

admits, however, that the intemperate, profligate, and criminal classes, whose duration of life is low, do not

commonly marry; and it must likewise be admitted that men with a weak constitution, ill health, or any great

infirmity in body or mind, will often not wish to marry, or will be rejected. Dr. Stark seems to have come to

the conclusion that marriage in itself is a main cause of prolonged life, from finding that aged married men

still have a considerable advantage in this respect over the unmarried of the same advanced age; but every

one must have known instances of men, who with weak health during youth did not marry, and yet have

survived to old age, though remaining weak, and therefore always with a lessened chance of life or of

marrying. There is another remarkable circumstance which seems to support Dr. Stark's conclusion, namely,

that widows and widowers in France suffer in comparison with the married a very heavy rate of mortality; but

Dr. Farr attributes this to the poverty and evil habits consequent on the disruption of the family, and to grief.

On the whole we may conclude with Dr. Farr that the lesser mortality of married than of unmarried men,

which seems to be a general law, "is mainly due to the constant elimination of imperfect types, and to the

skilful selection of the finest individuals out of each successive generation;" the selection relating only to the

marriage state, and acting on all corporeal, intellectual, and moral qualities. (25. Dr. Duncan remarks

('Fecundity, Fertility, etc.' 1871, p. 334) on this subject: "At every age the healthy and beautiful go over from

the unmarried side to the married, leaving the unmarried columns crowded with the sickly and unfortunate.")

We may, therefore, infer that sound and good men who out of prudence remain for a time unmarried, do not

If the various checks specified in the two last paragraphs, and perhaps others as yet unknown, do not prevent

the reckless, the vicious and otherwise inferior members of society from increasing at a quicker rate than the

better class of men, the nation will retrograde, as has too often occurred in the history of the world. We must

remember that progress is no invariable rule. It is very difficult to say why one civilised nation rises, becomes

more powerful, and spreads more widely, than another; or why the same nation progresses more quickly at

one time than at another. We can only say that it depends on an increase in the actual number of the

population, on the number of men endowed with high intellectual and moral faculties, as well as on their

standard of excellence. Corporeal structure appears to have little influence, except so far as vigour of body

It has been urged by several writers that as high intellectual powers are advantageous to a nation, the old

Greeks, who stood some grades higher in intellect than any race that has ever existed (26. See the ingenious

and original argument on this subject by Mr. Galton, 'Hereditary Genius,' pp. 340342.), ought, if the power

of natural selection were real, to have risen still higher in the scale, increased in number, and stocked the

whole of Europe. Here we have the tacit assumption, so often made with respect to corporeal structures, that

there is some innate tendency towards continued development in mind and body. But development of all

kinds depends on many concurrent favourable circumstances. Natural selection acts only tentatively.

Individuals and races may have acquired certain indisputable advantages, and yet have perished from failing

in other characters. The Greeks may have retrograded from a want of coherence between the many small

states, from the small size of their whole country, from the practice of slavery, or from extreme sensuality; for

they did not succumb until "they were enervated and corrupt to the very core." (27. Mr. Greg, 'Fraser's

Magazine,' Sept. 1868, p. 357.) The western nations of Europe, who now so immeasurably surpass their

former savage progenitors, and stand at the summit of civilisation, owe little or none of their superiority to

direct inheritance from the old Greeks, though they owe much to the written works of that wonderful people.

Who can positively say why the Spanish nation, so dominant at one time, has been distanced in the race. The

awakening of the nations of Europe from the dark ages is a still more perplexing problem. At that early

period, as Mr. Galton has remarked, almost all the men of a gentle nature, those given to meditation or culture

of the mind, had no refuge except in the bosom of a Church which demanded celibacy (28. 'Hereditary

Genius,' 1870, pp. 357 359. The Rev. F.W. Farrar ('Fraser's Magazine,' Aug. 1870, p. 257) advances

arguments on the other side. Sir C. Lyell had already ('Principles of Geology,' vol. ii. 1868, p. 489), in a

striking passage called attention to the evil influence of the Holy Inquisition in having, through selection,

lowered the general standard of intelligence in Europe.); and this could hardly fail to have had a deteriorating

influence on each successive generation. During this same period the Holy Inquisition selected with extreme

care the freest and boldest men in order to burn or imprison them. In Spain alone some of the best

menthose who doubted and questioned, and without doubting there can be no progresswere eliminated

during three centuries at the rate of a thousand a year. The evil which the Catholic Church has thus effected is

incalculable, though no doubt counterbalanced to a certain, perhaps to a large, extent in other ways;

The remarkable success of the English as colonists, compared to other European nations, has been ascribed to

their "daring and persistent energy"; a result which is well illustrated by comparing the progress of the

Canadians of English and French extraction; but who can say how the English gained their energy? There is

apparently much truth in the belief that the wonderful progress of the United States, as well as the character

of the people, are the results of natural selection; for the more energetic, restless, and courageous men from

all parts of Europe have emigrated during the last ten or twelve generations to that great country, and have

there succeeded best. (29. Mr. Galton, 'Macmillan's Magazine,' August 1865, p. 325. See also, 'Nature,' 'On

Darwinism and National Life,' Dec. 1869, p. 184.) Looking to the distant future, I do not think that the Rev.

Mr. Zincke takes an exaggerated view when he says (30. 'Last Winter in the United States,' 1868, p. 29.): "All

other series of eventsas that which resulted in the culture of mind in Greece, and that which resulted in the

empire of Romeonly appear to have purpose and value when viewed in connection with, or rather as

subsidiary to...the great stream of Anglo Saxon emigration to the west." Obscure as is the problem of the

advance of civilisation, we can at least see that a nation which produced during a lengthened period the

greatest number of highly intellectual, energetic, brave, patriotic, and benevolent men, would generally

Natural selection follows from the struggle for existence; and this from a rapid rate of increase. It is

impossible not to regret bitterly, but whether wisely is another question, the rate at which man tends to

increase; for this leads in barbarous tribes to infanticide and many other evils, and in civilised nations to

abject poverty, celibacy, and to the late marriages of the prudent. But as man suffers from the same physical

evils as the lower animals, he has no right to expect an immunity from the evils consequent on the struggle

for existence. Had he not been subjected during primeval times to natural selection, assuredly he would never

have attained to his present rank. Since we see in many parts of the world enormous areas of the most fertile

land capable of supporting numerous happy homes, but peopled only by a few wandering savages, it might be

argued that the struggle for existence had not been sufficiently severe to force man upwards to his highest

standard. Judging from all that we know of man and the lower animals, there has always been sufficient

variability in their intellectual and moral faculties, for a steady advance through natural selection. No doubt

such advance demands many favourable concurrent circumstances; but it may well be doubted whether the

most favourable would have sufficed, had not the rate of increase been rapid, and the consequent struggle for

existence extremely severe. It even appears from what we see, for instance, in parts of S. America, that a

people which may be called civilised, such as the Spanish settlers, is liable to become indolent and to

retrograde, when the conditions of life are very easy. With highly civilised nations continued progress

depends in a subordinate degree on natural selection; for such nations do not supplant and exterminate one

another as do savage tribes. Nevertheless the more intelligent members within the same community will

succeed better in the long run than the inferior, and leave a more numerous progeny, and this is a form of

natural selection. The more efficient causes of progress seem to consist of a good education during youth

whilst the brain is impressible, and of a high standard of excellence, inculcated by the ablest and best men,

embodied in the laws, customs and traditions of the nation, and enforced by public opinion. It should,

however, be borne in mind, that the enforcement of public opinion depends on our appreciation of the

approbation and disapprobation of others; and this appreciation is founded on our sympathy, which it can

hardly be doubted was originally developed through natural selection as one of the most important elements

of the social instincts. (31. I am much indebted to Mr. John Morley for some good criticisms on this subject:

The present subject has been treated in so full and admirable a manner by Sir J. Lubbock (32. 'On the Origin

of Civilisation,' 'Proceedings of the Ethnological Society,' Nov. 26, 1867.), Mr. Tylor, Mr. M'Lennan, and

others, that I need here give only the briefest summary of their results. The arguments recently advanced by

the Duke of Argyll (33. 'Primeval Man,' 1869.) and formerly by Archbishop Whately, in favour of the belief

that man came into the world as a civilised being, and that all savages have since undergone degradation,

seem to me weak in comparison with those advanced on the other side. Many nations, no doubt, have fallen

away in civilisation, and some may have lapsed into utter barbarism, though on this latter head I have met

with no evidence. The Fuegians were probably compelled by other conquering hordes to settle in their

inhospitable country, and they may have become in consequence somewhat more degraded; but it would be

difficult to prove that they have fallen much below the Botocudos, who inhabit the finest parts of Brazil.

The evidence that all civilised nations are the descendants of barbarians, consists, on the one side, of clear

traces of their former low condition in stillexisting customs, beliefs, language, etc.; and on the other side, of

proofs that savages are independently able to raise themselves a few steps in the scale of civilisation, and

have actually thus risen. The evidence on the first head is extremely curious, but cannot be here given: I refer

to such cases as that of the art of enumeration, which, as Mr. Tylor clearly shews by reference to the words

still used in some places, originated in counting the fingers, first of one hand and then of the other, and lastly

of the toes. We have traces of this in our own decimal system, and in the Roman numerals, where, after the

V, which is supposed to be an abbreviated picture of a human hand, we pass on to VI, etc., when the other

hand no doubt was used. So again, "when we speak of threescore and ten, we are counting by the vigesimal

system, each score thus ideally made, standing for 20for 'one man' as a Mexican or Carib would put it."

(34. 'Royal Institution of Great Britain,' March 15, 1867. Also, 'Researches into the Early History of

Mankind,' 1865.) According to a large and increasing school of philologists, every language bears the marks

of its slow and gradual evolution. So it is with the art of writing, for letters are rudiments of pictorial

representations. It is hardly possible to read Mr. M'Lennan's work (35. 'Primitive Marriage,' 1865. See,

likewise, an excellent article, evidently by the same author, in the 'North British Review,' July 1869. Also,

Mr. L.H. Morgan, 'A Conjectural Solution of the Origin of the Class, System of Relationship,' in 'Proc.

American Acad. of Sciences,' vol. vii. Feb. 1868. Prof. Schaaffhausen ('Anthropolog. Review,' Oct. 1869, p.

373) remarks on "the vestiges of human sacrifices found both in Homer and the Old Testament.") and not

admit that almost all civilised nations still retain traces of such rude habits as the forcible capture of wives.

What ancient nation, as the same author asks, can be named that was originally monogamous? The primitive

idea of justice, as shewn by the law of battle and other customs of which vestiges still remain, was likewise

most rude. Many existing superstitions are the remnants of former false religious beliefs. The highest form of

religion the grand idea of God hating sin and loving righteousnesswas unknown during primeval times.

Turning to the other kind of evidence: Sir J. Lubbock has shewn that some savages have recently improved a

little in some of their simpler arts. From the extremely curious account which he gives of the weapons, tools,

and arts, in use amongst savages in various parts of the world, it cannot be doubted that these have nearly all

been independent discoveries, excepting perhaps the art of making fire. (36. Sir J. Lubbock, 'Prehistoric

Times,' 2nd edit. 1869, chaps. xv. and xvi. et passim. See also the excellent 9th Chapter in Tylor's 'Early

History of Mankind,' 2nd edit., 1870.) The Australian boomerang is a good instance of one such independent

discovery. The Tahitians when first visited had advanced in many respects beyond the inhabitants of most of

the other Polynesian islands. There are no just grounds for the belief that the high culture of the native

Peruvians and Mexicans was derived from abroad (37. Dr. F. Muller has made some good remarks to this

effect in the 'Reise der Novara: Anthropolog. Theil,' Abtheil. iii. 1868, s. 127.); many native plants were there

cultivated, and a few native animals domesticated. We should bear in mind that, judging from the small

influence of most missionaries, a wandering crew from some semicivilised land, if washed to the shores of

America, would not have produced any marked effect on the natives, unless they had already become

somewhat advanced. Looking to a very remote period in the history of the world, we find, to use Sir J.

Lubbock's wellknown terms, a paleolithic and neolithic period; and no one will pretend that the art of

grinding rough flint tools was a borrowed one. In all parts of Europe, as far east as Greece, in Palestine, India,

Japan, New Zealand, and Africa, including Egypt, flint tools have been discovered in abundance; and of their

use the existing inhabitants retain no tradition. There is also indirect evidence of their former use by the

Chinese and ancient Jews. Hence there can hardly be a doubt that the inhabitants of these countries, which

include nearly the whole civilised world, were once in a barbarous condition. To believe that man was

aboriginally civilised and then suffered utter degradation in so many regions, is to take a pitiably low view of

human nature. It is apparently a truer and more cheerful view that progress has been much more general than

retrogression; that man has risen, though by slow and interrupted steps, from a lowly condition to the highest

Position of man in the animal seriesThe natural system genealogical Adaptive characters of slight

valueVarious small points of resemblance between man and the QuadrumanaRank of man in the natural

system Birthplace and antiquity of manAbsence of fossil connecting linksLower stages in the

genealogy of man, as inferred, firstly from his affinities and secondly from his structureEarly androgynous

Even if it be granted that the difference between man and his nearest allies is as great in corporeal structure as

some naturalists maintain, and although we must grant that the difference between them is immense in mental

power, yet the facts given in the earlier chapters appear to declare, in the plainest manner, that man is

descended from some lower form, notwithstanding that connectinglinks have not hitherto been discovered.

Man is liable to numerous, slight, and diversified variations, which are induced by the same general causes,

are governed and transmitted in accordance with the same general laws, as in the lower animals. Man has

multiplied so rapidly, that he has necessarily been exposed to struggle for existence, and consequently to

natural selection. He has given rise to many races, some of which differ so much from each other, that they

have often been ranked by naturalists as distinct species. His body is constructed on the same homological

plan as that of other mammals. He passes through the same phases of embryological development. He retains

many rudimentary and useless structures, which no doubt were once serviceable. Characters occasionally

make their reappearance in him, which we have reason to believe were possessed by his early progenitors. If

the origin of man had been wholly different from that of all other animals, these various appearances would

be mere empty deceptions; but such an admission is incredible. These appearances, on the other hand, are

intelligible, at least to a large extent, if man is the codescendant with other mammals of some unknown and

Some naturalists, from being deeply impressed with the mental and spiritual powers of man, have divided the

whole organic world into three kingdoms, the Human, the Animal, and the Vegetable, thus giving to man a

separate kingdom. (1. Isidore Geoffroy St.Hilaire gives a detailed account of the position assigned to man

by various naturalists in their classifications: 'Hist. Nat. Gen.' tom. ii. 1859, pp. 170189.) Spiritual powers

cannot be compared or classed by the naturalist: but he may endeavour to shew, as I have done, that the

mental faculties of man and the lower animals do not differ in kind, although immensely in degree. A

difference in degree, however great, does not justify us in placing man in a distinct kingdom, as will perhaps

be best illustrated by comparing the mental powers of two insects, namely, a coccus or scaleinsect and an

ant, which undoubtedly belong to the same class. The difference is here greater than, though of a somewhat

different kind from, that between man and the highest mammal. The female coccus, whilst young, attaches

itself by its proboscis to a plant; sucks the sap, but never moves again; is fertilised and lays eggs; and this is

its whole history. On the other hand, to describe the habits and mental powers of workerants, would require,

as Pierre Huber has shewn, a large volume; I may, however, briefly specify a few points. Ants certainly

communicate information to each other, and several unite for the same work, or for games of play. They

recognise their fellowants after months of absence, and feel sympathy for each other. They build great

edifices, keep them clean, close the doors in the evening, and post sentries. They make roads as well as

tunnels under rivers, and temporary bridges over them, by clinging together. They collect food for the

community, and when an object, too large for entrance, is brought to the nest, they enlarge the door, and

afterwards build it up again. They store up seeds, of which they prevent the germination, and which, if damp,

are brought up to the surface to dry. They keep aphides and other insects as milchcows. They go out to

battle in regular bands, and freely sacrifice their lives for the common weal. They emigrate according to a

preconcerted plan. They capture slaves. They move the eggs of their aphides, as well as their own eggs and

cocoons, into warm parts of the nest, in order that they may be quickly hatched; and endless similar facts

could be given. (2. Some of the most interesting facts ever published on the habits of ants are given by Mr.

Belt, in his 'Naturalist in Nicaragua,' 1874. See also Mr. Moggridge's admirable work, 'Harvesting Ants,' etc.,

1873, also 'L'Instinct chez les Insectes,' by M. George Pouchet, 'Revue des Deux Mondes,' Feb. 1870, p. 682.)

On the whole, the difference in mental power between an ant and a coccus is immense; yet no one has ever

dreamed of placing these insects in distinct classes, much less in distinct kingdoms. No doubt the difference

is bridged over by other insects; and this is not the case with man and the higher apes. But we have every

reason to believe that the breaks in the series are simply the results of many forms having become extinct.

Professor Owen, relying chiefly on the structure of the brain, has divided the mammalian series into four

subclasses. One of these he devotes to man; in another he places both the marsupials and the Monotremata;

so that he makes man as distinct from all other mammals as are these two latter groups conjoined. This view

has not been accepted, as far as I am aware, by any naturalist capable of forming an independent judgment,

We can understand why a classification founded on any single character or organeven an organ so

wonderfully complex and important as the brainor on the high development of the mental faculties, is

almost sure to prove unsatisfactory. This principle has indeed been tried with hymenopterous insects; but

when thus classed by their habits or instincts, the arrangement proved thoroughly artificial. (3. Westwood,

'Modern Classification of Insects,' vol. ii. 1840, p. 87.) Classifications may, of course, be based on any

character whatever, as on size, colour, or the element inhabited; but naturalists have long felt a profound

conviction that there is a natural system. This system, it is now generally admitted, must be, as far as

possible, genealogical in arrangement,that is, the co descendants of the same form must be kept together

in one group, apart from the codescendants of any other form; but if the parentforms are related, so will be

their descendants, and the two groups together will form a larger group. The amount of difference between

the several groupsthat is the amount of modification which each has undergoneis expressed by such

terms as genera, families, orders, and classes. As we have no record of the lines of descent, the pedigree can

be discovered only by observing the degrees of resemblance between the beings which are to be classed. For

this object numerous points of resemblance are of much more importance than the amount of similarity or

dissimilarity in a few points. If two languages were found to resemble each other in a multitude of words and

points of construction, they would be universally recognised as having sprung from a common source,

notwithstanding that they differed greatly in some few words or points of construction. But with organic

beings the points of resemblance must not consist of adaptations to similar habits of life: two animals may,

for instance, have had their whole frames modified for living in the water, and yet they will not be brought

any nearer to each other in the natural system. Hence we can see how it is that resemblances in several

unimportant structures, in useless and rudimentary organs, or not now functionally active, or in an

embryological condition, are by far the most serviceable for classification; for they can hardly be due to

adaptations within a late period; and thus they reveal the old lines of descent or of true affinity.

We can further see why a great amount of modification in some one character ought not to lead us to separate

widely any two organisms. A part which already differs much from the same part in other allied forms has

already, according to the theory of evolution, varied much; consequently it would (as long as the organism

remained exposed to the same exciting conditions) be liable to further variations of the same kind; and these,

if beneficial, would be preserved, and thus be continually augmented. In many cases the continued

development of a part, for instance, of the beak of a bird, or of the teeth of a mammal, would not aid the

species in gaining its food, or for any other object; but with man we can see no definite limit to the continued

development of the brain and mental faculties, as far as advantage is concerned. Therefore in determining the

position of man in the natural or genealogical system, the extreme development of his brain ought not to

outweigh a multitude of resemblances in other less important or quite unimportant points.

The greater number of naturalists who have taken into consideration the whole structure of man, including his

mental faculties, have followed Blumenbach and Cuvier, and have placed man in a separate Order, under the

title of the Bimana, and therefore on an equality with the orders of the Quadrumana, Carnivora, etc. Recently

many of our best naturalists have recurred to the view first propounded by Linnaeus, so remarkable for his

sagacity, and have placed man in the same Order with the Quadrumana, under the title of the Primates. The

justice of this conclusion will be admitted: for in the first place, we must bear in mind the comparative

insignificance for classification of the great development of the brain in man, and that the stronglymarked

differences between the skulls of man and the Quadrumana (lately insisted upon by Bischoff, Aeby, and

others) apparently follow from their differently developed brains. In the second place, we must remember that

nearly all the other and more important differences between man and the Quadrumana are manifestly

adaptive in their nature, and relate chiefly to the erect position of man; such as the structure of his hand, foot,

and pelvis, the curvature of his spine, and the position of his head. The family of Seals offers a good

illustration of the small importance of adaptive characters for classification. These animals differ from all

other Carnivora in the form of their bodies and in the structure of their limbs, far more than does man from

the higher apes; yet in most systems, from that of Cuvier to the most recent one by Mr. Flower (4.

'Proceedings Zoological Society,' 1863, p. 4.), seals are ranked as a mere family in the Order of the

Carnivora. If man had not been his own classifier, he would never have thought of founding a separate order

It would be beyond my limits, and quite beyond my knowledge, even to name the innumerable points of

structure in which man agrees with the other Primates. Our great anatomist and philosopher, Prof. Huxley,

has fully discussed this subject (5. 'Evidence as to Man's Place in Nature,' 1863, p. 70, et passim.), and

concludes that man in all parts of his organization differs less from the higher apes, than these do from the

lower members of the same group. Consequently there "is no justification for placing man in a distinct order."

In an early part of this work I brought forward various facts, shewing how closely man agrees in constitution

with the higher mammals; and this agreement must depend on our close similarity in minute structure and

chemical composition. I gave, as instances, our liability to the same diseases, and to the attacks of allied

parasites; our tastes in common for the same stimulants, and the similar effects produced by them, as well as

As small unimportant points of resemblance between man and the Quadrumana are not commonly noticed in

systematic works, and as, when numerous, they clearly reveal our relationship, I will specify a few such

points. The relative position of our features is manifestly the same; and the various emotions are displayed by

nearly similar movements of the muscles and skin, chiefly above the eyebrows and round the mouth. Some

few expressions are, indeed, almost the same, as in the weeping of certain kinds of monkeys and in the

laughing noise made by others, during which the corners of the mouth are drawn backwards, and the lower

eyelids wrinkled. The external ears are curiously alike. In man the nose is much more prominent than in most

monkeys; but we may trace the commencement of an aquiline curvature in the nose of the Hoolock Gibbon;

The faces of many monkeys are ornamented with beards, whiskers, or moustaches. The hair on the head

grows to a great length in some species of Semnopithecus (6. Isidore Geoffroy St.Hilaire, 'Hist. Nat. Gen.'

tom. ii. 1859, p. 217.); and in the Bonnet monkey (Macacus radiatus) it radiates from a point on the crown,

with a parting down the middle. It is commonly said that the forehead gives to man his noble and intellectual

appearance; but the thick hair on the head of the Bonnet monkey terminates downwards abruptly, and is

succeeded by hair so short and fine that at a little distance the forehead, with the exception of the eyebrows,

appears quite naked. It has been erroneously asserted that eyebrows are not present in any monkey. In the

species just named the degree of nakedness of the forehead differs in different individuals; and Eschricht

states (7. 'Uber die Richtung der Haare,' etc., Muller's 'Archiv fur Anat. und Phys.' 1837, s. 51.) that in our

children the limit between the hairy scalp and the naked forehead is sometimes not well defined; so that here

we seem to have a trifling case of reversion to a progenitor, in whom the forehead had not as yet become

It is well known that the hair on our arms tends to converge from above and below to a point at the elbow.

This curious arrangement, so unlike that in most of the lower mammals, is common to the gorilla,

chimpanzee, orang, some species of Hylobates, and even to some few American monkeys. But in Hylobates

agilis the hair on the forearm is directed downwards or towards the wrist in the ordinary manner; and in H.

lar it is nearly erect, with only a very slight forward inclination; so that in this latter species it is in a

transitional state. It can hardly be doubted that with most mammals the thickness of the hair on the back and

its direction, is adapted to throw off the rain; even the transverse hairs on the forelegs of a dog may serve for

this end when he is coiled up asleep. Mr. Wallace, who has carefully studied the habits of the orang, remarks

that the convergence of the hair towards the elbow on the arms of the orang may be explained as serving to

throw off the rain, for this animal during rainy weather sits with its arms bent, and with the hands clasped

round a branch or over its head. According to Livingstone, the gorilla also "sits in pelting rain with his hands

over his head." (8. Quoted by Reade, 'The African Sketch Book,' vol i. 1873, p. 152.) If the above explanation

is correct, as seems probable, the direction of the hair on our own arms offers a curious record of our former

state; for no one supposes that it is now of any use in throwing off the rain; nor, in our present erect

It would, however, be rash to trust too much to the principle of adaptation in regard to the direction of the hair

in man or his early progenitors; for it is impossible to study the figures given by Eschricht of the arrangement

of the hair on the human foetus (this being the same as in the adult) and not agree with this excellent observer

that other and more complex causes have intervened. The points of convergence seem to stand in some

relation to those points in the embryo which are last closed in during development. There appears, also, to

exist some relation between the arrangement of the hair on the limbs, and the course of the medullary arteries.

(9. On the hair in Hylobates, see 'Natural History of Mammals,' by C.L. Martin, 1841, p. 415. Also, Isidore

Geoffroy on the American monkeys and other kinds, 'Hist. Nat. Gen.' vol. ii. 1859, pp. 216, 243. Eschricht,

ibid. s. 46, 55, 61. Owen, 'Anatomy of Vertebrates,' vol. iii. p. 619. Wallace, 'Contributions to the Theory of

It must not be supposed that the resemblances between man and certain apes in the above and in many other

pointssuch as in having a naked forehead, long tresses on the head, etc.,are all necessarily the result of

unbroken inheritance from a common progenitor, or of subsequent reversion. Many of these resemblances are

more probably due to analogous variation, which follows, as I have elsewhere attempted to shew (10. 'Origin

of Species,' 5th edit. 1869, p.194. 'The Variation of Animals and Plants under Domestication,' vol. ii. 1868, p.

348.), from codescended organisms having a similar constitution, and having been acted on by like causes

inducing similar modifications. With respect to the similar direction of the hair on the forearms of man and

certain monkeys, as this character is common to almost all the anthropomorphous apes, it may probably be

attributed to inheritance; but this is not certain, as some very distinct American monkeys are thus

Although, as we have now seen, man has no just right to form a separate Order for his own reception, he may

perhaps claim a distinct Suborder or Family. Prof. Huxley, in his last work (11. 'An Introduction to the

Classification of Animals,' 1869, p. 99.), divides the primates into three Suborders; namely, the Anthropidae

with man alone, the Simiadae including monkeys of all kinds, and the Lemuridae with the diversified genera

of lemurs. As far as differences in certain important points of structure are concerned, man may no doubt

rightly claim the rank of a Suborder; and this rank is too low, if we look chiefly to his mental faculties.

Nevertheless, from a genealogical point of view it appears that this rank is too high, and that man ought to

form merely a Family, or possibly even only a Sub family. If we imagine three lines of descent proceeding

from a common stock, it is quite conceivable that two of them might after the lapse of ages be so slightly

changed as still to remain as species of the same genus, whilst the third line might become so greatly

modified as to deserve to rank as a distinct Subfamily, Family, or even Order. But in this case it is almost

certain that the third line would still retain through inheritance numerous small points of resemblance with

the other two. Here, then, would occur the difficulty, at present insoluble, how much weight we ought to

assign in our classifications to stronglymarked differences in some few points,that is, to the amount of

modification undergone; and how much to close resemblance in numerous unimportant points, as indicating

the lines of descent or genealogy. To attach much weight to the few but strong differences is the most

obvious and perhaps the safest course, though it appears more correct to pay great attention to the many small

In forming a judgment on this head with reference to man, we must glance at the classification of the

Simiadae. This family is divided by almost all naturalists into the Catarrhine group, or Old World monkeys,

all of which are characterised (as their name expresses) by the peculiar structure of their nostrils, and by

having four premolars in each jaw; and into the Platyrrhine group or New World monkeys (including two

very distinct sub groups), all of which are characterised by differently constructed nostrils, and by having

six premolars in each jaw. Some other small differences might be mentioned. Now man unquestionably

belongs in his dentition, in the structure of his nostrils, and some other respects, to the Catarrhine or Old

World division; nor does he resemble the Platyrrhines more closely than the Catarrhines in any characters,

excepting in a few of not much importance and apparently of an adaptive nature. It is therefore against all

probability that some New World species should have formerly varied and produced a manlike creature,

with all the distinctive characters proper to the Old World division; losing at the same time all its own

distinctive characters. There can, consequently, hardly be a doubt that man is an offshoot from the Old

World Simian stem; and that under a genealogical point of view he must be classed with the Catarrhine

division. (12. This is nearly the same classification as that provisionally adopted by Mr. St. George Mivart,

('Transactions, Philosophical Society," 1867, p. 300), who, after separating the Lemuridae, divides the

remainder of the Primates into the Hominidae, the Simiadae which answer to the Catarrhines, the Cebidae,

and the Hapalidae,these two latter groups answering to the Platyrrhines. Mr. Mivart still abides by the

The anthropomorphous apes, namely the gorilla, chimpanzee, orang, and hylobates, are by most naturalists

separated from the other Old World monkeys, as a distinct subgroup. I am aware that Gratiolet, relying on

the structure of the brain, does not admit the existence of this subgroup, and no doubt it is a broken one.

Thus the orang, as Mr. St. G. Mivart remarks, "is one of the most peculiar and aberrant forms to be found in

the Order." (13. 'Transactions, Zoolog. Soc.' vol. vi. 1867, p. 214.) The remaining nonanthropomorphous

Old World monkeys, are again divided by some naturalists into two or three smaller subgroups; the genus

Semnopithecus, with its peculiar sacculated stomach, being the type of one subgroup. But it appears from

M. Gaudry's wonderful discoveries in Attica, that during the Miocene period a form existed there, which

connected Semnopithecus and Macacus; and this probably illustrates the manner in which the other and

If the anthropomorphous apes be admitted to form a natural subgroup, then as man agrees with them, not

only in all those characters which he possesses in common with the whole Catarrhine group, but in other

peculiar characters, such as the absence of a tail and of callosities, and in general appearance, we may infer

that some ancient member of the anthropomorphous subgroup gave birth to man. It is not probable that,

through the law of analogous variation, a member of one of the other lower subgroups should have given

rise to a manlike creature, resembling the higher anthropomorphous apes in so many respects. No doubt

man, in comparison with most of his allies, has undergone an extraordinary amount of modification, chiefly

in consequence of the great development of his brain and his erect position; nevertheless, we should bear in

mind that he "is but one of several exceptional forms of Primates." (14. Mr. St. G. Mivart, 'Transactions of

Every naturalist, who believes in the principle of evolution, will grant that the two main divisions of the

Simiadae, namely the Catarrhine and Platyrrhine monkeys, with their subgroups, have all proceeded from

some one extremely ancient progenitor. The early descendants of this progenitor, before they had diverged to

any considerable extent from each other, would still have formed a single natural group; but some of the

species or incipient genera would have already begun to indicate by their diverging characters the future

distinctive marks of the Catarrhine and Platyrrhine divisions. Hence the members of this supposed ancient

group would not have been so uniform in their dentition, or in the structure of their nostrils, as are the

existing Catarrhine monkeys in one way and the Platyrrhines in another way, but would have resembled in

this respect the allied Lemuridae, which differ greatly from each other in the form of their muzzles (15.

Messrs. Murie and Mivart on the Lemuroidea, 'Transactions, Zoological Society,' vol. vii, 1869, p. 5.), and to

The Catarrhine and Platyrrhine monkeys agree in a multitude of characters, as is shewn by their

unquestionably belonging to one and the same Order. The many characters which they possess in common

can hardly have been independently acquired by so many distinct species; so that these characters must have

been inherited. But a naturalist would undoubtedly have ranked as an ape or a monkey, an ancient form

which possessed many characters common to the Catarrhine and Platyrrhine monkeys, other characters in an

intermediate condition, and some few, perhaps, distinct from those now found in either group. And as man

from a genealogical point of view belongs to the Catarrhine or Old World stock, we must conclude, however

much the conclusion may revolt our pride, that our early progenitors would have been properly thus

designated. (16. Haeckel has come to this same conclusion. See 'Uber die Entstehung des

Menschengeschlechts,' in Virchow's 'Sammlung. gemein. wissen. Vortrage,' 1868, s. 61. Also his 'Naturliche

Schopfungsgeschicte,' 1868, in which he gives in detail his views on the genealogy of man.) But we must not

fall into the error of supposing that the early progenitor of the whole Simian stock, including man, was

We are naturally led to enquire, where was the birthplace of man at that stage of descent when our

progenitors diverged from the Catarrhine stock? The fact that they belonged to this stock clearly shews that

they inhabited the Old World; but not Australia nor any oceanic island, as we may infer from the laws of

geographical distribution. In each great region of the world the living mammals are closely related to the

extinct species of the same region. It is therefore probable that Africa was formerly inhabited by extinct apes

closely allied to the gorilla and chimpanzee; and as these two species are now man's nearest allies, it is

somewhat more probable that our early progenitors lived on the African continent than elsewhere. But it is

useless to speculate on this subject; for two or three anthropomorphous apes, one the Dryopithecus (17. Dr.

C. Forsyth Major, 'Sur les Singes fossiles trouves en Italie:' 'Soc. Ital. des Sc. Nat.' tom. xv. 1872.) of Lartet,

nearly as large as a man, and closely allied to Hylobates, existed in Europe during the Miocene age; and since

so remote a period the earth has certainly undergone many great revolutions, and there has been ample time

At the period and place, whenever and wherever it was, when man first lost his hairy covering, he probably

inhabited a hot country; a circumstance favourable for the frugiferous diet on which, judging from analogy,

he subsisted. We are far from knowing how long ago it was when man first diverged from the Catarrhine

stock; but it may have occurred at an epoch as remote as the Eocene period; for that the higher apes had

diverged from the lower apes as early as the Upper Miocene period is shewn by the existence of the

Dryopithecus. We are also quite ignorant at how rapid a rate organisms, whether high or low in the scale,

may be modified under favourable circumstances; we know, however, that some have retained the same form

during an enormous lapse of time. From what we see going on under domestication, we learn that some of the

codescendants of the same species may be not at all, some a little, and some greatly changed, all within the

same period. Thus it may have been with man, who has undergone a great amount of modification in certain

The great break in the organic chain between man and his nearest allies, which cannot be bridged over by any

extinct or living species, has often been advanced as a grave objection to the belief that man is descended

from some lower form; but this objection will not appear of much weight to those who, from general reasons,

believe in the general principle of evolution. Breaks often occur in all parts of the series, some being wide,

sharp and defined, others less so in various degrees; as between the orang and its nearest alliesbetween the

Tarsius and the other Lemuridaebetween the elephant, and in a more striking manner between the

Ornithorhynchus or Echidna, and all other mammals. But these breaks depend merely on the number of

related forms which have become extinct. At some future period, not very distant as measured by centuries,

the civilised races of man will almost certainly exterminate, and replace, the savage races throughout the

world. At the same time the anthropomorphous apes, as Professor Schaaffhausen has remarked (18.

'Anthropological Review,' April 1867, p. 236.), will no doubt be exterminated. The break between man and

his nearest allies will then be wider, for it will intervene between man in a more civilised state, as we may

hope, even than the Caucasian, and some ape as low as a baboon, instead of as now between the negro or

With respect to the absence of fossil remains, serving to connect man with his apelike progenitors, no one

will lay much stress on this fact who reads Sir C. Lyell's discussion (19. 'Elements of Geology,' 1865, pp.

583 585. 'Antiquity of Man,' 1863, p. 145.), where he shews that in all the vertebrate classes the discovery

of fossil remains has been a very slow and fortuitous process. Nor should it be forgotten that those regions

which are the most likely to afford remains connecting man with some extinct ape like creature, have not as

We have seen that man appears to have diverged from the Catarrhine or Old World division of the Simiadae,

after these had diverged from the New World division. We will now endeavour to follow the remote traces of

his genealogy, trusting principally to the mutual affinities between the various classes and orders, with some

slight reference to the periods, as far as ascertained, of their successive appearance on the earth. The

Lemuridae stand below and near to the Simiadae, and constitute a very distinct family of the primates, or,

according to Haeckel and others, a distinct Order. This group is diversified and broken to an extraordinary

degree, and includes many aberrant forms. It has, therefore, probably suffered much extinction. Most of the

remnants survive on islands, such as Madagascar and the Malayan archipelago, where they have not been

exposed to so severe a competition as they would have been on wellstocked continents. This group likewise

presents many gradations, leading, as Huxley remarks (20. 'Man's Place in Nature,' p. 105.), "insensibly from

the crown and summit of the animal creation down to creatures from which there is but a step, as it seems, to

the lowest, smallest, and least intelligent of the placental mammalia." From these various considerations it is

probable that the Simiadae were originally developed from the progenitors of the existing Lemuridae; and

The Marsupials stand in many important characters below the placental mammals. They appeared at an

earlier geological period, and their range was formerly much more extensive than at present. Hence the

Placentata are generally supposed to have been derived from the Implacentata or Marsupials; not, however,

from forms closely resembling the existing Marsupials, but from their early progenitors. The Monotremata

are plainly allied to the Marsupials, forming a third and still lower division in the great mammalian series.

They are represented at the present day solely by the Ornithorhynchus and Echidna; and these two forms may

be safely considered as relics of a much larger group, representatives of which have been preserved in

Australia through some favourable concurrence of circumstances. The Monotremata are eminently

interesting, as leading in several important points of structure towards the class of reptiles.

In attempting to trace the genealogy of the Mammalia, and therefore of man, lower down in the series, we

become involved in greater and greater obscurity; but as a most capable judge, Mr. Parker, has remarked, we

have good reason to believe, that no true bird or reptile intervenes in the direct line of descent. He who

wishes to see what ingenuity and knowledge can effect, may consult Prof. Haeckel's works. (21. Elaborate

tables are given in his 'Generelle Morphologie' (B. ii. s. cliii. and s. 425); and with more especial reference to

man in his 'Naturliche Schopfungsgeschichte,' 1868. Prof. Huxley, in reviewing this latter work ('The

Academy,' 1869, p. 42) says, that he considers the phylum or lines of descent of the Vertebrata to be

admirably discussed by Haeckel, although he differs on some points. He expresses, also, his high estimate of

the general tenor and spirit of the whole work.) I will content myself with a few general remarks. Every

evolutionist will admit that the five great vertebrate classes, namely, mammals, birds, reptiles, amphibians,

and fishes, are descended from some one prototype; for they have much in common, especially during their

embryonic state. As the class of fishes is the most lowly organised, and appeared before the others, we may

conclude that all the members of the vertebrate kingdom are derived from some fishlike animal. The belief

that animals so distinct as a monkey, an elephant, a hummingbird, a snake, a frog, and a fish, etc., could all

have sprung from the same parents, will appear monstrous to those who have not attended to the recent

progress of natural history. For this belief implies the former existence of links binding closely together all

Nevertheless, it is certain that groups of animals have existed, or do now exist, which serve to connect several

of the great vertebrate classes more or less closely. We have seen that the Ornithorhynchus graduates towards

reptiles; and Prof. Huxley has discovered, and is confirmed by Mr. Cope and others, that the Dinosaurians are

in many important characters intermediate between certain reptiles and certain birdsthe birds referred to

being the ostrichtribe (itself evidently a widelydiffused remnant of a larger group) and the Archeopteryx,

that strange Secondary bird, with a long lizardlike tail. Again, according to Prof. Owen (22. 'Palaeontology'

1860, p. 199.), the Ichthyosauriansgreat sealizards furnished with paddlespresent many affinities with

fishes, or rather, according to Huxley, with amphibians; a class which, including in its highest division frogs

and toads, is plainly allied to the Ganoid fishes. These latter fishes swarmed during the earlier geological

periods, and were constructed on what is called a generalised type, that is, they presented diversified affinities

with other groups of organisms. The Lepidosiren is also so closely allied to amphibians and fishes, that

naturalists long disputed in which of these two classes to rank it; it, and also some few Ganoid fishes, have

been preserved from utter extinction by inhabiting rivers, which are harbours of refuge, and are related to the

Lastly, one single member of the immense and diversified class of fishes, namely, the lancelet or amphioxus,

is so different from all other fishes, that Haeckel maintains that it ought to form a distinct class in the

vertebrate kingdom. This fish is remarkable for its negative characters; it can hardly be said to possess a

brain, vertebral column, or heart, etc.; so that it was classed by the older naturalists amongst the worms.

Many years ago Prof. Goodsir perceived that the lancelet presented some affinities with the Ascidians, which

are invertebrate, hermaphrodite, marine creatures permanently attached to a support. They hardly appear like

animals, and consist of a simple, tough, leathery sack, with two small projecting orifices. They belong to the

Mulluscoida of Huxleya lower division of the great kingdom of the Mollusca; but they have recently been

placed by some naturalists amongst the Vermes or worms. Their larvae somewhat resemble tadpoles in shape

(23. At the Falkland Islands I had the satisfaction of seeing, in April, 1833, and therefore some years before

any other naturalist, the locomotive larvae of a compound Ascidian, closely allied to Synoicum, but

apparently generically distinct from it. The tail was about five times as long as the oblong head, and

terminated in a very fine filament. It was, as sketched by me under a simple microscope, plainly divided by

transverse opaque partitions, which I presume represent the great cells figured by Kovalevsky. At an early

stage of development the tail was closely coiled round the head of the larva.), and have the power of

swimming freely about. Mr. Kovalevsky (24. 'Memoires de l'Acad. des Sciences de St. Petersbourg,' tom. x.

No. 15, 1866.) has lately observed that the larvae of Ascidians are related to the Vertebrata, in their manner of

development, in the relative position of the nervous system, and in possessing a structure closely like the

chorda dorsalis of vertebrate animals; and in this he has been since confirmed by Prof. Kupffer. M.

Kovalevsky writes to me from Naples, that he has now carried these observations yet further, and should his

results be well established, the whole will form a discovery of the very greatest value. Thus, if we may rely

on embryology, ever the safest guide in classification, it seems that we have at last gained a clue to the source

whence the Vertebrata were derived. (25. But I am bound to add that some competent judges dispute this

conclusion; for instance, M. Giard, in a series of papers in the 'Archives de Zoologie Experimentale,' for

1872. Nevertheless, this naturalist remarks, p. 281, "L'organisation de la larve ascidienne en dehors de toute

hypothese et de toute theorie, nous montre comment la nature peut produire la disposition fondamentale du

type vertebre (l'existence d'une corde dorsale) chez un invertebre par la seule condition vitale de l'adaptation,

et cette simple possibilite du passage supprime l'abime entre les deux sousregnes, encore bien qu'en ignore

par ou le passage s'est fait en realite.") We should then be justified in believing that at an extremely remote

period a group of animals existed, resembling in many respects the larvae of our present Ascidians, which

diverged into two great branchesthe one retrograding in development and producing the present class of

Ascidians, the other rising to the crown and summit of the animal kingdom by giving birth to the Vertebrata.

We have thus far endeavoured rudely to trace the genealogy of the Vertebrata by the aid of their mutual

affinities. We will now look to man as he exists; and we shall, I think, be able partially to restore the structure

of our early progenitors, during successive periods, but not in due order of time. This, can be effected by

means of the rudiments which man still retains, by the characters which occasionally make their appearance

in him through reversion, and by the aid of the principles of morphology and embryology. The various facts,

The early progenitors of man must have been once covered with hair, both sexes having beards; their ears

were probably pointed, and capable of movement; and their bodies were provided with a tail, having the

proper muscles. Their limbs and bodies were also acted on by many muscles which now only occasionally

reappear, but are normally present in the Quadrumana. At this or some earlier period, the great artery and

nerve of the humerus ran through a supracondyloid foramen. The intestine gave forth a much larger

diverticulum or caecum than that now existing. The foot was then prehensile, judging from the condition of

the great toe in the foetus; and our progenitors, no doubt, were arboreal in their habits, and frequented some

warm, forestclad land. The males had great canine teeth, which served them as formidable weapons. At a

much earlier period the uterus was double; the excreta were voided through a cloaca; and the eye was

protected by a third eyelid or nictitating membrane. At a still earlier period the progenitors of man must have

been aquatic in their habits; for morphology plainly tells us that our lungs consist of a modified

swimbladder, which once served as a float. The clefts on the neck in the embryo of man shew where the

branchiae once existed. In the lunar or weekly recurrent periods of some of our functions we apparently still

retain traces of our primordial birthplace, a shore washed by the tides. At about this same early period the true

kidneys were replaced by the corpora wolffiana. The heart existed as a simple pulsating vessel; and the

chorda dorsalis took the place of a vertebral column. These early ancestors of man, thus seen in the dim

recesses of time, must have been as simply, or even still more simply organised than the lancelet or

There is one other point deserving a fuller notice. It has long been known that in the vertebrate kingdom one

sex bears rudiments of various accessory parts, appertaining to the reproductive system, which properly

belong to the opposite sex; and it has now been ascertained that at a very early embryonic period both sexes

possess true male and female glands. Hence some remote progenitor of the whole vertebrate kingdom appears

to have been hermaphrodite or androgynous. (26. This is the conclusion of Prof. Gegenbaur, one of the

highest authorities in comparative anatomy: see 'Grundzuge der vergleich. Anat.' 1870, s. 876. The result has

been arrived at chiefly from the study of the Amphibia; but it appears from the researches of Waldeyer (as

quoted in 'Journal of Anat. and Phys.' 1869, p. 161), that the sexual organs of even "the higher vertebrata are,

in their early condition, hermaphrodite." Similar views have long been held by some authors, though until

recently without a firm basis.) But here we encounter a singular difficulty. In the mammalian class the males

possess rudiments of a uterus with the adjacent passage, in their vesiculae prostaticae; they bear also

rudiments of mammae, and some male Marsupials have traces of a marsupial sack. (27. The male Thylacinus

offers the best instance. Owen, 'Anatomy of Vertebrates,' vol. iii. p. 771.) Other analogous facts could be

added. Are we, then, to suppose that some extremely ancient mammal continued androgynous, after it had

acquired the chief distinctions of its class, and therefore after it had diverged from the lower classes of the

vertebrate kingdom? This seems very improbable, for we have to look to fishes, the lowest of all the classes,

to find any still existent androgynous forms. (28. Hermaphroditism has been observed in several species of

Serranus, as well as in some other fishes, where it is either normal and symmetrical, or abnormal and

unilateral. Dr. Zouteveen has given me references on this subject, more especially to a paper by Prof.

Halbertsma, in the 'Transact. of the Dutch Acad. of Sciences,' vol. xvi. Dr. Gunther doubts the fact, but it has

now been recorded by too many good observers to be any longer disputed. Dr. M. Lessona writes to me, that

he has verified the observations made by Cavolini on Serranus. Prof. Ercolani has recently shewn ('Accad.

delle Scienze,' Bologna, Dec. 28, 1871) that eels are androgynous.) That various accessory parts, proper to

each sex, are found in a rudimentary condition in the opposite sex, may be explained by such organs having

been gradually acquired by the one sex, and then transmitted in a more or less imperfect state to the other.

When we treat of sexual selection, we shall meet with innumerable instances of this form of

transmission,as in the case of the spurs, plumes, and brilliant colours, acquired for battle or ornament by

male birds, and inherited by the females in an imperfect or rudimentary condition.

The possession by male mammals of functionally imperfect mammary organs is, in some respects, especially

curious. The Monotremata have the proper milksecreting glands with orifices, but no nipples; and as these

animals stand at the very base of the mammalian series, it is probable that the progenitors of the class also

had milksecreting glands, but no nipples. This conclusion is supported by what is known of their manner of

development; for Professor Turner informs me, on the authority of Kolliker and Langer, that in the embryo

the mammary glands can be distinctly traced before the nipples are in the least visible; and the development

of successive parts in the individual generally represents and accords with the development of successive

beings in the same line of descent. The Marsupials differ from the Monotremata by possessing nipples; so

that probably these organs were first acquired by the Marsupials, after they had diverged from, and risen

above, the Monotremata, and were then transmitted to the placental mammals. (29. Prof. Gegenbaur has

shewn ('Jenaische Zeitschrift,' Bd. vii. p. 212) that two distinct types of nipples prevail throughout the several

mammalian orders, but that it is quite intelligible how both could have been derived from the nipples of the

Marsupials, and the latter from those of the Monotremata. See, also, a memoir by Dr. Max Huss, on the

mammary glands, ibid. B. viii. p. 176.) No one will suppose that the marsupials still remained androgynous,

after they had approximately acquired their present structure. How then are we to account for male mammals

possessing mammae? It is possible that they were first developed in the females and then transferred to the

It may be suggested, as another view, that long after the progenitors of the whole mammalian class had

ceased to be androgynous, both sexes yielded milk, and thus nourished their young; and in the case of the

Marsupials, that both sexes carried their young in marsupial sacks. This will not appear altogether

improbable, if we reflect that the males of existing syngnathous fishes receive the eggs of the females in their

abdominal pouches, hatch them, and afterwards, as some believe, nourish the young (30. Mr. Lockwood

believes (as quoted in 'Quart. Journal of Science,' April 1868, p. 269), from what he has observed of the

development of Hippocampus, that the walls of the abdominal pouch of the male in some way afford

nourishment. On male fishes hatching the ova in their mouths, see a very interesting paper by Prof. Wyman,

in 'Proc. Boston Soc. of Nat. Hist.' Sept. 15, 1857; also Prof. Turner, in 'Journal of Anatomy and Physiology,'

Nov. 1, 1866, p. 78. Dr. Gunther has likewise described similar cases.); that certain other male fishes hatch

the eggs within their mouths or branchial cavities;that certain male toads take the chaplets of eggs from the

females, and wind them round their own thighs, keeping them there until the tadpoles are born;that certain

male birds undertake the whole duty of incubation, and that male pigeons, as well as the females, feed their

nestlings with a secretion from their crops. But the above suggestion first occurred to me from mammary

glands of male mammals being so much more perfectly developed than the rudiments of the other accessory

reproductive parts, which are found in the one sex though proper to the other. The mammary glands and

nipples, as they exist in male mammals, can indeed hardly be called rudimentary; they are merely not fully

developed, and not functionally active. They are sympathetically affected under the influence of certain

diseases, like the same organs in the female. They often secrete a few drops of milk at birth and at puberty:

this latter fact occurred in the curious case, before referred to, where a young man possessed two pairs of

mammae. In man and some other male mammals these organs have been known occasionally to become so

well developed during maturity as to yield a fair supply of milk. Now if we suppose that during a former

prolonged period male mammals aided the females in nursing their offspring (31. Mlle. C. Royer has

suggested a similar view in her 'Origine de l'homme,' etc., 1870.), and that afterwards from some cause (as

from the production of a smaller number of young) the males ceased to give this aid, disuse of the organs

during maturity would lead to their becoming inactive; and from two wellknown principles of inheritance,

this state of inactivity would probably be transmitted to the males at the corresponding age of maturity. But at

an earlier age these organs would be left unaffected, so that they would be almost equally well developed in

Von Baer has defined advancement or progress in the organic scale better than any one else, as resting on the

amount of differentiation and specialisation of the several parts of a being,when arrived at maturity, as I

should be inclined to add. Now as organisms have become slowly adapted to diversified lines of life by

means of natural selection, their parts will have become more and more differentiated and specialised for

various functions from the advantage gained by the division of physiological labour. The same part appears

often to have been modified first for one purpose, and then long afterwards for some other and quite distinct

purpose; and thus all the parts are rendered more and more complex. But each organism still retains the

general type of structure of the progenitor from which it was aboriginally derived. In accordance with this

view it seems, if we turn to geological evidence, that organisation on the whole has advanced throughout the

world by slow and interrupted steps. In the great kingdom of the Vertebrata it has culminated in man. It must

not, however, be supposed that groups of organic beings are always supplanted, and disappear as soon as they

have given birth to other and more perfect groups. The latter, though victorious over their predecessors, may

not have become better adapted for all places in the economy of nature. Some old forms appear to have

survived from inhabiting protected sites, where they have not been exposed to very severe competition; and

these often aid us in constructing our genealogies, by giving us a fair idea of former and lost populations. But

we must not fall into the error of looking at the existing members of any lowlyorganised group as perfect

The most ancient progenitors in the kingdom of the Vertebrata, at which we are able to obtain an obscure

glance, apparently consisted of a group of marine animals (32. The inhabitants of the seashore must be

greatly affected by the tides; animals living either about the MEAN highwater mark, or about the MEAN

lowwater mark, pass through a complete cycle of tidal changes in a fortnight. Consequently, their food

supply will undergo marked changes week by week. The vital functions of such animals, living under these

conditions for many generations, can hardly fail to run their course in regular weekly periods. Now it is a

mysterious fact that in the higher and now terrestrial Vertebrata, as well as in other classes, many normal and

abnormal processes have one or more whole weeks as their periods; this would be rendered intelligible if the

Vertebrata are descended from an animal allied to the existing tidal Ascidians. Many instances of such

periodic processes might be given, as the gestation of mammals, the duration of fevers, etc. The hatching of

eggs affords also a good example, for, according to Mr. Bartlett ('Land and Water,' Jan. 7, 1871), the eggs of

the pigeon are hatched in two weeks; those of the fowl in three; those of the duck in four; those of the goose

in five; and those of the ostrich in seven weeks. As far as we can judge, a recurrent period, if approximately

of the right duration for any process or function, would not, when once gained, be liable to change;

consequently it might be thus transmitted through almost any number of generations. But if the function

changed, the period would have to change, and would be apt to change almost abruptly by a whole week.

This conclusion, if sound, is highly remarkable; for the period of gestation in each mammal, and the hatching

of each bird's eggs, and many other vital processes, thus betray to us the primordial birthplace of these

animals.), resembling the larvae of existing Ascidians. These animals probably gave rise to a group of fishes,

as lowly organised as the lancelet; and from these the Ganoids, and other fishes like the Lepidosiren, must

have been developed. From such fish a very small advance would carry us on to the Amphibians. We have

seen that birds and reptiles were once intimately connected together; and the Monotremata now connect

mammals with reptiles in a slight degree. But no one can at present say by what line of descent the three

higher and related classes, namely, mammals, birds, and reptiles, were derived from the two lower vertebrate

classes, namely, amphibians and fishes. In the class of mammals the steps are not difficult to conceive which

led from the ancient Monotremata to the ancient Marsupials; and from these to the early progenitors of the

placental mammals. We may thus ascend to the Lemuridae; and the interval is not very wide from these to the

Simiadae. The Simiadae then branched off into two great stems, the New World and Old World monkeys;

and from the latter, at a remote period, Man, the wonder and glory of the Universe, proceeded.

Thus we have given to man a pedigree of prodigious length, but not, it may be said, of noble quality. The

world, it has often been remarked, appears as if it had long been preparing for the advent of man: and this, in

one sense is strictly true, for he owes his birth to a long line of progenitors. If any single link in this chain had

never existed, man would not have been exactly what he now is. Unless we wilfully close our eyes, we may,

with our present knowledge, approximately recognise our parentage; nor need we feel ashamed of it. The

most humble organism is something much higher than the inorganic dust under our feet; and no one with an

unbiassed mind can study any living creature, however humble, without being struck with enthusiasm at its

The nature and value of specific charactersApplication to the races of manArguments in favour of, and

opposed to, ranking the socalled races of man as district speciesSubspeciesMonogenists and

polygenists Convergence of characterNumerous points of resemblance in body and mind between the

most distinct races of manThe state of man when he first spread over the earthEach race not descended

from a single pairThe extinction of racesThe formation of racesThe effects of crossing Slight

influence of the direct action of the conditions of lifeSlight or no influence of natural selectionSexual

It is not my intention here to describe the several socalled races of men; but I am about to enquire what is

the value of the differences between them under a classificatory point of view, and how they have originated.

In determining whether two or more allied forms ought to be ranked as species or varieties, naturalists are

practically guided by the following considerations; namely, the amount of difference between them, and

whether such differences relate to few or many points of structure, and whether they are of physiological

importance; but more especially whether they are constant. Constancy of character is what is chiefly valued

and sought for by naturalists. Whenever it can be shewn, or rendered probable, that the forms in question

have remained distinct for a long period, this becomes an argument of much weight in favour of treating them

as species. Even a slight degree of sterility between any two forms when first crossed, or in their offspring, is

generally considered as a decisive test of their specific distinctness; and their continued persistence without

blending within the same area, is usually accepted as sufficient evidence, either of some degree of mutual

Independently of fusion from intercrossing, the complete absence, in a wellinvestigated region, of varieties

linking together any two closely allied forms, is probably the most important of all the criterions of their

specific distinctness; and this is a somewhat different consideration from mere constancy of character, for

two forms may be highly variable and yet not yield intermediate varieties. Geographical distribution is often

brought into play unconsciously and sometimes consciously; so that forms living in two widely separated

areas, in which most of the other inhabitants are specifically distinct, are themselves usually looked at as

distinct; but in truth this affords no aid in distinguishing geographical races from socalled good or true

Now let us apply these generallyadmitted principles to the races of man, viewing him in the same spirit as a

naturalist would any other animal. In regard to the amount of difference between the races, we must make

some allowance for our nice powers of discrimination gained by the long habit of observing ourselves. In

India, as Elphinstone remarks, although a newly arrived European cannot at first distinguish the various

native races, yet they soon appear to him extremely dissimilar (1. 'History of India,' 1841, vol. i. p. 323.

Father Ripa makes exactly the same remark with respect to the Chinese.); and the Hindoo cannot at first

perceive any difference between the several European nations. Even the most distinct races of man are much

more like each other in form than would at first be supposed; certain negro tribes must be excepted, whilst

others, as Dr. Rohlfs writes to me, and as I have myself seen, have Caucasian features. This general similarity

is well shewn by the French photographs in the Collection Anthropologique du Museum de Paris of the men

belonging to various races, the greater number of which might pass for Europeans, as many persons to whom

I have shewn them have remarked. Nevertheless, these men, if seen alive, would undoubtedly appear very

distinct, so that we are clearly much influenced in our judgment by the mere colour of the skin and hair, by

There is, however, no doubt that the various races, when carefully compared and measured, differ much from

each other,as in the texture of the hair, the relative proportions of all parts of the body (2. A vast number of

measurements of Whites, Blacks, and Indians, are given in the 'Investigations in the Military and

Anthropolog. Statistics of American Soldiers,' by B.A. Gould, 1869, pp. 298358; 'On the capacity of the

lungs,' p. 471. See also the numerous and valuable tables, by Dr. Weisbach, from the observations of Dr.

Scherzer and Dr. Schwarz, in the 'Reise der Novara: Anthropolog. Theil,' 1867.), the capacity of the lungs,

the form and capacity of the skull, and even in the convolutions of the brain. (3. See, for instance, Mr.

Marshall's account of the brain of a Bushwoman, in 'Philosophical Transactions,' 1864, p. 519.) But it would

be an endless task to specify the numerous points of difference. The races differ also in constitution, in

acclimatisation and in liability to certain diseases. Their mental characteristics are likewise very distinct;

chiefly as it would appear in their emotional, but partly in their intellectual faculties. Every one who has had

the opportunity of comparison, must have been struck with the contrast between the taciturn, even morose,

aborigines of S. America and the lighthearted, talkative negroes. There is a nearly similar contrast between

the Malays and the Papuans (4. Wallace, 'The Malay Archipelago,' vol. ii. 1869, p. 178.), who live under the

same physical conditions, and are separated from each other only by a narrow space of sea.

We will first consider the arguments which may be advanced in favour of classing the races of man as distinct

species, and then the arguments on the other side. If a naturalist, who had never before seen a Negro,

Hottentot, Australian, or Mongolian, were to compare them, he would at once perceive that they differed in a

multitude of characters, some of slight and some of considerable importance. On enquiry he would find that

they were adapted to live under widely different climates, and that they differed somewhat in bodily

constitution and mental disposition. If he were then told that hundreds of similar specimens could be brought

from the same countries, he would assuredly declare that they were as good species as many to which he had

been in the habit of affixing specific names. This conclusion would be greatly strengthened as soon as he had

ascertained that these forms had all retained the same character for many centuries; and that negroes,

apparently identical with existing negroes, had lived at least 4000 years ago. (5. With respect to the figures in

the famous Egyptian caves of AbouSimbel, M. Pouchet says ('The Plurality of the Human Races,' Eng.

translat., 1864, p. 50), that he was far from finding recognisable representations of the dozen or more nations

which some authors believe that they can recognise. Even some of the most strongly marked races cannot be

identified with that degree of unanimity which might have been expected from what has been written on the

subject. Thus Messrs. Nott and Gliddon ('Types of Mankind,' p. 148), state that Rameses II., or the Great, has

features superbly European; whereas Knox, another firm believer in the specific distinctness of the races of

man ('Races of Man,' 1850, p. 201), speaking of young Memnon (the same as Rameses II., as I am informed

by Mr. Birch), insists in the strongest manner that he is identical in character with the Jews of Antwerp.

Again, when I looked at the statue of Amunoph III., I agreed with two officers of the establishment, both

competent judges, that he had a stronglymarked negro type of features; but Messrs. Nott and Gliddon (ibid.

p. 146, fig. 53), describe him as a hybrid, but not of "negro intermixture.") He would also hear, on the

authority of an excellent observer, Dr. Lund (6. As quoted by Nott and Gliddon, 'Types of Mankind,' 1854, p.

439. They give also corroborative evidence; but C. Vogt thinks that the subject requires further

investigation.), that the human skulls found in the caves of Brazil, entombed with many extinct mammals,

belonged to the same type as that now prevailing throughout the American Continent.

Our naturalist would then perhaps turn to geographical distribution, and he would probably declare that those

forms must be distinct species, which differ not only in appearance, but are fitted for hot, as well as damp or

dry countries, and for the Artic regions. He might appeal to the fact that no species in the group next to

mannamely, the Quadrumana, can resist a low temperature, or any considerable change of climate; and

that the species which come nearest to man have never been reared to maturity, even under the temperate

climate of Europe. He would be deeply impressed with the fact, first noticed by Agassiz (7. 'Diversity of

Origin of the Human Races,' in the 'Christian Examiner,' July 1850.), that the different races of man are

distributed over the world in the same zoological provinces, as those inhabited by undoubtedly distinct

species and genera of mammals. This is manifestly the case with the Australian, Mongolian, and Negro races

of man; in a less wellmarked manner with the Hottentots; but plainly with the Papuans and Malays, who are

separated, as Mr. Wallace has shewn, by nearly the same line which divides the great Malayan and Australian

zoological provinces. The Aborigines of America range throughout the Continent; and this at first appears

opposed to the above rule, for most of the productions of the Southern and Northern halves differ widely: yet

some few living forms, as the opossum, range from the one into the other, as did formerly some of the

gigantic Edentata. The Esquimaux, like other Arctic animals, extend round the whole polar regions. It should

be observed that the amount of difference between the mammals of the several zoological provinces does not

correspond with the degree of separation between the latter; so that it can hardly be considered as an anomaly

that the Negro differs more, and the American much less from the other races of man, than do the mammals

of the African and American continents from the mammals of the other provinces. Man, it may be added,

does not appear to have aboriginally inhabited any oceanic island; and in this respect, he resembles the other

In determining whether the supposed varieties of the same kind of domestic animal should be ranked as such,

or as specifically distinct, that is, whether any of them are descended from distinct wild species, every

naturalist would lay much stress on the fact of their external parasites being specifically distinct. All the more

stress would be laid on this fact, as it would be an exceptional one; for I am informed by Mr. Denny that the

most different kinds of dogs, fowls, and pigeons, in England, are infested by the same species of Pediculi or

lice. Now Mr. A. Murray has carefully examined the Pediculi collected in different countries from the

different races of man (8. 'Transactions of the Royal Society of Edinburgh,' vol. xxii, 1861, p. 567.); and he

finds that they differ, not only in colour, but in the structure of their claws and limbs. In every case in which

many specimens were obtained the differences were constant. The surgeon of a whaling ship in the Pacific

assured me that when the Pediculi, with which some Sandwich Islanders on board swarmed, strayed on to the

bodies of the English sailors, they died in the course of three or four days. These Pediculi were darker

coloured, and appeared different from those proper to the natives of Chiloe in South America, of which he

gave me specimens. These, again, appeared larger and much softer than European lice. Mr. Murray procured

four kinds from Africa, namely, from the Negroes of the Eastern and Western coasts, from the Hottentots and

Kaffirs; two kinds from the natives of Australia; two from North and two from South America. In these latter

cases it may be presumed that the Pediculi came from natives inhabiting different districts. With insects slight

structural differences, if constant, are generally esteemed of specific value: and the fact of the races of man

being infested by parasites, which appear to be specifically distinct, might fairly be urged as an argument that

Our supposed naturalist having proceeded thus far in his investigation, would next enquire whether the races

of men, when crossed, were in any degree sterile. He might consult the work (9. 'On the Phenomena of

Hybridity in the Genus Homo,' Eng. translat., 1864.) of Professor Broca, a cautious and philosophical

observer, and in this he would find good evidence that some races were quite fertile together, but evidence of

an opposite nature in regard to other races. Thus it has been asserted that the native women of Australia and

Tasmania rarely produce children to European men; the evidence, however, on this head has now been shewn

to be almost valueless. The halfcastes are killed by the pure blacks: and an account has lately been

published of eleven halfcaste youths murdered and burnt at the same time, whose remains were found by the

police. (10. See the interesting letter by Mr. T.A. Murray, in the 'Anthropological Review,' April 1868, p. liii.

In this letter Count Strzelecki's statement that Australian women who have borne children to a white man, are

afterwards sterile with their own race, is disproved. M. A. de Quatrefages has also collected (Revue des

Cours Scientifiques, March, 1869, p. 239), much evidence that Australians and Europeans are not sterile

when crossed.) Again, it has often been said that when mulattoes intermarry, they produce few children; on

the other hand, Dr. Bachman, of Charleston (11. 'An Examination of Prof. Agassiz's Sketch of the Nat.

Provinces of the Animal World,' Charleston, 1855, p. 44.), positively asserts that he has known mulatto

families which have intermarried for several generations, and have continued on an average as fertile as either

pure whites or pure blacks. Enquiries formerly made by Sir C. Lyell on this subject led him, as he informs

me, to the same conclusion. (12. Dr. Rohlfs writes to me that he found the mixed races in the Great Sahara,

derived from Arabs, Berbers, and Negroes of three tribes, extraordinarily fertile. On the other hand, Mr.

Winwood Reade informs me that the Negroes on the Gold Coast, though admiring white men and mulattoes,

have a maxim that mulattoes should not intermarry, as the children are few and sickly. This belief, as Mr.

Reade remarks, deserves attention, as white men have visited and resided on the Gold Coast for four hundred

years, so that the natives have had ample time to gain knowledge through experience.) In the United States

the census for the year 1854 included, according to Dr. Bachman, 405,751 mulattoes; and this number,

considering all the circumstances of the case, seems small; but it may partly be accounted for by the degraded

and anomalous position of the class, and by the profligacy of the women. A certain amount of absorption of

mulattoes into negroes must always be in progress; and this would lead to an apparent diminution of the

former. The inferior vitality of mulattoes is spoken of in a trustworthy work (13. 'Military and

Anthropological Statistics of American Soldiers,' by B.A. Gould, 1869, p. 319.) as a wellknown

phenomenon; and this, although a different consideration from their lessened fertility, may perhaps be

advanced as a proof of the specific distinctness of the parent races. No doubt both animal and vegetable

hybrids, when produced from extremely distinct species, are liable to premature death; but the parents of

mulattoes cannot be put under the category of extremely distinct species. The common Mule, so notorious for

long life and vigour, and yet so sterile, shews how little necessary connection there is in hybrids between

Even if it should hereafter be proved that all the races of men were perfectly fertile together, he who was

inclined from other reasons to rank them as distinct species, might with justice argue that fertility and sterility

are not safe criterions of specific distinctness. We know that these qualities are easily affected by changed

conditions of life, or by close interbreeding, and that they are governed by highly complex laws, for

instance, that of the unequal fertility of converse crosses between the same two species. With forms which

must be ranked as undoubted species, a perfect series exists from those which are absolutely sterile when

crossed, to those which are almost or completely fertile. The degrees of sterility do not coincide strictly with

the degrees of difference between the parents in external structure or habits of life. Man in many respects may

be compared with those animals which have long been domesticated, and a large body of evidence can be

advanced in favour of the Pallasian doctrine (14. The 'Variation of Animals and Plants under Domestication,'

vol. ii. p. 109. I may here remind the reader that the sterility of species when crossed is not a

speciallyacquired quality, but, like the incapacity of certain trees to be grafted together, is incidental on

other acquired differences. The nature of these differences is unknown, but they relate more especially to the

reproductive system, and much less so to external structure or to ordinary differences in constitution. One

important element in the sterility of crossed species apparently lies in one or both having been long

habituated to fixed conditions; for we know that changed conditions have a special influence on the

reproductive system, and we have good reason to believe (as before remarked) that the fluctuating conditions

of domestication tend to eliminate that sterility which is so general with species, in a natural state, when

crossed. It has elsewhere been shewn by me (ibid. vol. ii. p. 185, and 'Origin of Species,' 5th edit. p. 317), that

the sterility of crossed species has not been acquired through natural selection: we can see that when two

forms have already been rendered very sterile, it is scarcely possible that their sterility should be augmented

by the preservation or survival of the more and more sterile individuals; for, as the sterility increases, fewer

and fewer offspring will be produced from which to breed, and at last only single individuals will be

produced at the rarest intervals. But there is even a higher grade of sterility than this. Both Gartner and

Kolreuter have proved that in genera of plants, including many species, a series can be formed from species

which, when crossed, yield fewer and fewer seeds, to species which never produce a single seed, but yet are

affected by the pollen of the other species, as shewn by the swelling of the germen. It is here manifestly

impossible to select the more sterile individuals, which have already ceased to yield seeds; so that the acme of

sterility, when the germen alone is affected, cannot have been gained through selection. This acme, and no

doubt the other grades of sterility, are the incidental results of certain unknown differences in the constitution

of the reproductive system of the species which are crossed.), that domestication tends to eliminate the

sterility which is so general a result of the crossing of species in a state of nature. From these several

considerations, it may be justly urged that the perfect fertility of the intercrossed races of man, if established,

Independently of fertility, the characters presented by the offspring from a cross have been thought to indicate

whether or not the parentforms ought to be ranked as species or varieties; but after carefully studying the

evidence, I have come to the conclusion that no general rules of this kind can be trusted. The ordinary result

of a cross is the production of a blended or intermediate form; but in certain cases some of the offspring take

closely after one parentform, and some after the other. This is especially apt to occur when the parents differ

in characters which first appeared as sudden variations or monstrosities. (15. 'The Variation of Animals,' etc.,

vol. ii. p. 92.) I refer to this point, because Dr. Rohlfs informs me that he has frequently seen in Africa the

offspring of negroes crossed with members of other races, either completely black or completely white, or

rarely piebald. On the other hand, it is notorious that in America mulattoes commonly present an intermediate

We have now seen that a naturalist might feel himself fully justified in ranking the races of man as distinct

species; for he has found that they are distinguished by many differences in structure and constitution, some

being of importance. These differences have, also, remained nearly constant for very long periods of time.

Our naturalist will have been in some degree influenced by the enormous range of man, which is a great

anomaly in the class of mammals, if mankind be viewed as a single species. He will have been struck with

the distribution of the several socalled races, which accords with that of other undoubtedly distinct species

of mammals. Finally, he might urge that the mutual fertility of all the races has not as yet been fully proved,

On the other side of the question, if our supposed naturalist were to enquire whether the forms of man keep

distinct like ordinary species, when mingled together in large numbers in the same country, he would

immediately discover that this was by no means the case. In Brazil he would behold an immense mongrel

population of Negroes and Portuguese; in Chiloe, and other parts of South America, he would behold the

whole population consisting of Indians and Spaniards blended in various degrees. (16. M. de Quatrefages has

given ('Anthropological Review,' Jan. 1869, p. 22), an interesting account of the success and energy of the

Paulistas in Brazil, who are a much crossed race of Portuguese and Indians, with a mixture of the blood of

other races.) In many parts of the same continent he would meet with the most complex crosses between

Negroes, Indians, and Europeans; and judging from the vegetable kingdom, such triple crosses afford the

severest test of the mutual fertility of the parent forms. In one island of the Pacific he would find a small

population of mingled Polynesian and English blood; and in the Fiji Archipelago a population of Polynesian

and Negritos crossed in all degrees. Many analogous cases could be added; for instance, in Africa. Hence the

races of man are not sufficiently distinct to inhabit the same country without fusion; and the absence of fusion

Our naturalist would likewise be much disturbed as soon as he perceived that the distinctive characters of all

the races were highly variable. This fact strikes every one on first beholding the negro slaves in Brazil, who

have been imported from all parts of Africa. The same remark holds good with the Polynesians, and with

many other races. It may be doubted whether any character can be named which is distinctive of a race and is

constant. Savages, even within the limits of the same tribe, are not nearly so uniform in character, as has been

often asserted. Hottentot women offer certain peculiarities, more strongly marked than those occurring in any

other race, but these are known not to be of constant occurrence. In the several American tribes, colour and

hairiness differ considerably; as does colour to a certain degree, and the shape of the features greatly, in the

Negroes of Africa. The shape of the skull varies much in some races (17. For instance, with the aborigines of

America and Australia, Prof. Huxley says ('Transact. Internat. Congress of Prehist. Arch.' 1868, p. 105), that

the skulls of many South Germans and Swiss are "as short and as broad as those of the Tartars," etc.); and so

it is with every other character. Now all naturalists have learnt by dearly bought experience, how rash it is to

But the most weighty of all the arguments against treating the races of man as distinct species, is that they

graduate into each other, independently in many cases, as far as we can judge, of their having intercrossed.

Man has been studied more carefully than any other animal, and yet there is the greatest possible diversity

amongst capable judges whether he should be classed as a single species or race, or as two (Virey), as three

(Jacquinot), as four (Kant), five (Blumenbach), six (Buffon), seven (Hunter), eight (Agassiz), eleven

(Pickering), fifteen (Bory St. Vincent), sixteen (Desmoulins), twentytwo (Morton), sixty (Crawfurd), or as

sixty three, according to Burke. (18. See a good discussion on this subject in Waitz, 'Introduction to

Anthropology,' Eng. translat., 1863, pp. 198208, 227. I have taken some of the above statements from H.

Tuttle's 'Origin and Antiquity of Physical Man,' Boston, 1866, p. 35.) This diversity of judgment does not

prove that the races ought not to be ranked as species, but it shews that they graduate into each other, and that

Every naturalist who has had the misfortune to undertake the description of a group of highly varying

organisms, has encountered cases (I speak after experience) precisely like that of man; and if of a cautious

disposition, he will end by uniting all the forms which graduate into each other, under a single species; for he

will say to himself that he has no right to give names to objects which he cannot define. Cases of this kind

occur in the Order which includes man, namely in certain genera of monkeys; whilst in other genera, as in

Cercopithecus, most of the species can be determined with certainty. In the American genus Cebus, the

various forms are ranked by some naturalists as species, by others as mere geographical races. Now if

numerous specimens of Cebus were collected from all parts of South America, and those forms which at

present appear to be specifically distinct, were found to graduate into each other by close steps, they would

usually be ranked as mere varieties or races; and this course has been followed by most naturalists with

respect to the races of man. Nevertheless, it must be confessed that there are forms, at least in the vegetable

kingdom (19. Prof. Nageli has carefully described several striking cases in his 'Botanische Mittheilungen,' B.

ii. 1866, ss. 294369. Prof. Asa Gray has made analogous remarks on some intermediate forms in the

Compositae of N. America.), which we cannot avoid naming as species, but which are connected together by

Some naturalists have lately employed the term "subspecies" to designate forms which possess many of the

characteristics of true species, but which hardly deserve so high a rank. Now if we reflect on the weighty

arguments above given, for raising the races of man to the dignity of species, and the insuperable difficulties

on the other side in defining them, it seems that the term "subspecies" might here be used with propriety.

But from long habit the term "race" will perhaps always be employed. The choice of terms is only so far

important in that it is desirable to use, as far as possible, the same terms for the same degrees of difference.

Unfortunately this can rarely be done: for the larger genera generally include closely allied forms, which

can be distinguished only with much difficulty, whilst the smaller genera within the same family include

forms that are perfectly distinct; yet all must be ranked equally as species. So again, species within the same

large genus by no means resemble each other to the same degree: on the contrary, some of them can generally

be arranged in little groups round other species, like satellites round planets. (20. 'Origin of Species,' 5th edit.

The question whether mankind consists of one or several species has of late years been much discussed by

anthropologists, who are divided into the two schools of monogenists and polygenists. Those who do not

admit the principle of evolution, must look at species as separate creations, or in some manner as distinct

entities; and they must decide what forms of man they will consider as species by the analogy of the method

commonly pursued in ranking other organic beings as species. But it is a hopeless endeavour to decide this

point, until some definition of the term "species" is generally accepted; and the definition must not include an

indeterminate element such as an act of creation. We might as well attempt without any definition to decide

whether a certain number of houses should be called a village, town, or city. We have a practical illustration

of the difficulty in the neverending doubts whether many closelyallied mammals, birds, insects, and plants,

which represent each other respectively in North America and Europe, should be ranked as species or

geographical races; and the like holds true of the productions of many islands situated at some little distance

Those naturalists, on the other hand, who admit the principle of evolution, and this is now admitted by the

majority of rising men, will feel no doubt that all the races of man are descended from a single primitive

stock; whether or not they may think fit to designate the races as distinct species, for the sake of expressing

their amount of difference. (21. See Prof. Huxley to this effect in the 'Fortnightly Review,' 1865, p. 275.)

With our domestic animals the question whether the various races have arisen from one or more species is

somewhat different. Although it may be admitted that all the races, as well as all the natural species within

the same genus, have sprung from the same primitive stock, yet it is a fit subject for discussion, whether all

the domestic races of the dog, for instance, have acquired their present amount of difference since some one

species was first domesticated by man; or whether they owe some of their characters to inheritance from

distinct species, which had already been differentiated in a state of nature. With man no such question can

arise, for he cannot be said to have been domesticated at any particular period.

During an early stage in the divergence of the races of man from a common stock, the differences between

the races and their number must have been small; consequently as far as their distinguishing characters are

concerned, they then had less claim to rank as distinct species than the existing socalled races. Nevertheless,

so arbitrary is the term of species, that such early races would perhaps have been ranked by some naturalists

as distinct species, if their differences, although extremely slight, had been more constant than they are at

It is however possible, though far from probable, that the early progenitors of man might formerly have

diverged much in character, until they became more unlike each other than any now existing races; but that

subsequently, as suggested by Vogt (22. 'Lectures on Man,' Eng. translat., 1864, p. 468.), they converged in

character. When man selects the offspring of two distinct species for the same object, he sometimes induces a

considerable amount of convergence, as far as general appearance is concerned. This is the case, as shewn by

von Nathusius (23. 'Die Rassen des Schweines,' 1860, s. 46. 'Vorstudien fur Geschichte,' etc.,

Schweinesschadel, 1864, s. 104. With respect to cattle, see M. de Quatrefages, 'Unite de l'Espece Humaine,'

1861, p. 119.), with the improved breeds of the pig, which are descended from two distinct species; and in a

less marked manner with the improved breeds of cattle. A great anatomist, Gratiolet, maintains that the

anthropomorphous apes do not form a natural subgroup; but that the orang is a highly developed gibbon or

semnopithecus, the chimpanzee a highly developed macacus, and the gorilla a highly developed mandrill. If

this conclusion, which rests almost exclusively on braincharacters, be admitted, we should have a case of

convergence at least in external characters, for the anthropomorphous apes are certainly more like each other

in many points, than they are to other apes. All analogical resemblances, as of a whale to a fish, may indeed

be said to be cases of convergence; but this term has never been applied to superficial and adaptive

resemblances. It would, however, be extremely rash to attribute to convergence close similarity of character

in many points of structure amongst the modified descendants of widely distinct beings. The form of a crystal

is determined solely by the molecular forces, and it is not surprising that dissimilar substances should

sometimes assume the same form; but with organic beings we should bear in mind that the form of each

depends on an infinity of complex relations, namely on variations, due to causes far too intricate to be

followed,on the nature of the variations preserved, these depending on the physical conditions, and still

more on the surrounding organisms which compete with each,and lastly, on inheritance (in itself a

fluctuating element) from innumerable progenitors, all of which have had their forms determined through

equally complex relations. It appears incredible that the modified descendants of two organisms, if these

differed from each other in a marked manner, should ever afterwards converge so closely as to lead to a near

approach to identity throughout their whole organisation. In the case of the convergent races of pigs above

referred to, evidence of their descent from two primitive stocks is, according to von Nathusius, still plainly

retained, in certain bones of their skulls. If the races of man had descended, as is supposed by some

naturalists, from two or more species, which differed from each other as much, or nearly as much, as does the

orang from the gorilla, it can hardly be doubted that marked differences in the structure of certain bones

Although the existing races of man differ in many respects, as in colour, hair, shape of skull, proportions of

the body, etc., yet if their whole structure be taken into consideration they are found to resemble each other

closely in a multitude of points. Many of these are of so unimportant or of so singular a nature, that it is

extremely improbable that they should have been independently acquired by aboriginally distinct species or

races. The same remark holds good with equal or greater force with respect to the numerous points of mental

similarity between the most distinct races of man. The American aborigines, Negroes and Europeans are as

different from each other in mind as any three races that can be named; yet I was incessantly struck, whilst

living with the Feugians on board the "Beagle," with the many little traits of character, shewing how similar

their minds were to ours; and so it was with a fullblooded negro with whom I happened once to be intimate.

He who will read Mr. Tylor's and Sir J. Lubbock's interesting works (24. Tylor's 'Early History of Mankind,'

1865: with respect to gesture language, see p. 54. Lubbock's 'Prehistoric Times,' 2nd edit. 1869.) can hardly

fail to be deeply impressed with the close similarity between the men of all races in tastes, dispositions and

habits. This is shewn by the pleasure which they all take in dancing, rude music, acting, painting, tattooing,

and otherwise decorating themselves; in their mutual comprehension of gesturelanguage, by the same

expression in their features, and by the same inarticulate cries, when excited by the same emotions. This

similarity, or rather identity, is striking, when contrasted with the different expressions and cries made by

distinct species of monkeys. There is good evidence that the art of shooting with bows and arrows has not

been handed down from any common progenitor of mankind, yet as Westropp and Nilsson have remarked

(25. 'On Analogous Forms of Implements,' in 'Memoirs of Anthropological Society' by H.M. Westropp. 'The

Primitive Inhabitants of Scandinavia,' Eng. translat., edited by Sir J. Lubbock, 1868, p. 104.), the stone

arrowheads, brought from the most distant parts of the world, and manufactured at the most remote periods,

are almost identical; and this fact can only be accounted for by the various races having similar inventive or

mental powers. The same observation has been made by archaeologists (26. Westropp 'On Cromlechs,' etc.,

'Journal of Ethnological Soc.' as given in 'Scientific Opinion,' June 2nd, 1869, p. 3.) with respect to certain

widelyprevalent ornaments, such as zigzags, etc.; and with respect to various simple beliefs and customs,

such as the burying of the dead under megalithic structures. I remember observing in South America (27.

'Journal of Researches: Voyage of the "Beagle,"' p. 46.), that there, as in so many other parts of the world,

men have generally chosen the summits of lofty hills, to throw up piles of stones, either as a record of some

Now when naturalists observe a close agreement in numerous small details of habits, tastes, and dispositions

between two or more domestic races, or between nearlyallied natural forms, they use this fact as an

argument that they are descended from a common progenitor who was thus endowed; and consequently that

all should be classed under the same species. The same argument may be applied with much force to the

As it is improbable that the numerous and unimportant points of resemblance between the several races of

man in bodily structure and mental faculties (I do not here refer to similar customs) should all have been

independently acquired, they must have been inherited from progenitors who had these same characters. We

thus gain some insight into the early state of man, before he had spread step by step over the face of the earth.

The spreading of man to regions widely separated by the sea, no doubt, preceded any great amount of

divergence of character in the several races; for otherwise we should sometimes meet with the same race in

distinct continents; and this is never the case. Sir J. Lubbock, after comparing the arts now practised by

savages in all parts of the world, specifies those which man could not have known, when he first wandered

from his original birthplace; for if once learnt they would never have been forgotten. (28. 'Prehistoric Times,'

1869, p. 574.) He thus shews that "the spear, which is but a development of the knifepoint, and the club,

which is but a long hammer, are the only things left." He admits, however, that the art of making fire

probably had been already discovered, for it is common to all the races now existing, and was known to the

ancient caveinhabitants of Europe. Perhaps the art of making rude canoes or rafts was likewise known; but

as man existed at a remote epoch, when the land in many places stood at a very different level to what it does

now, he would have been able, without the aid of canoes, to have spread widely. Sir J. Lubbock further

remarks how improbable it is that our earliest ancestors could have "counted as high as ten, considering that

so many races now in existence cannot get beyond four." Nevertheless, at this early period, the intellectual

and social faculties of man could hardly have been inferior in any extreme degree to those possessed at

present by the lowest savages; otherwise primeval man could not have been so eminently successful in the

From the fundamental differences between certain languages, some philologists have inferred that when man

first became widely diffused, he was not a speaking animal; but it may be suspected that languages, far less

perfect than any now spoken, aided by gestures, might have been used, and yet have left no traces on

subsequent and more highlydeveloped tongues. Without the use of some language, however imperfect, it

appears doubtful whether man's intellect could have risen to the standard implied by his dominant position at

Whether primeval man, when he possessed but few arts, and those of the rudest kind, and when his power of

language was extremely imperfect, would have deserved to be called man, must depend on the definition

which we employ. In a series of forms graduating insensibly from some apelike creature to man as he now

exists, it would be impossible to fix on any definite point where the term "man" ought to be used. But this is a

matter of very little importance. So again, it is almost a matter of indifference whether the socalled races of

man are thus designated, or are ranked as species or subspecies; but the latter term appears the more

appropriate. Finally, we may conclude that when the principle of evolution is generally accepted, as it surely

will be before long, the dispute between the monogenists and the polygenists will die a silent and unobserved

One other question ought not to be passed over without notice, namely, whether, as is sometimes assumed,

each subspecies or race of man has sprung from a single pair of progenitors. With our domestic animals a

new race can readily be formed by carefully matching the varying offspring from a single pair, or even from a

single individual possessing some new character; but most of our races have been formed, not intentionally

from a selected pair, but unconsciously by the preservation of many individuals which have varied, however

slightly, in some useful or desired manner. If in one country stronger and heavier horses, and in another

country lighter and fleeter ones, were habitually preferred, we may feel sure that two distinct subbreeds

would be produced in the course of time, without any one pair having been separated and bred from, in either

country. Many races have been thus formed, and their manner of formation is closely analogous to that of

natural species. We know, also, that the horses taken to the Falkland Islands have, during successive

generations, become smaller and weaker, whilst those which have run wild on the Pampas have acquired

larger and coarser heads; and such changes are manifestly due, not to any one pair, but to all the individuals

having been subjected to the same conditions, aided, perhaps, by the principle of reversion. The new sub

breeds in such cases are not descended from any single pair, but from many individuals which have varied in

different degrees, but in the same general manner; and we may conclude that the races of man have been

similarly produced, the modifications being either the direct result of exposure to different conditions, or the

indirect result of some form of selection. But to this latter subject we shall presently return.

The partial or complete extinction of many races and subraces of man is historically known. Humboldt saw

in South America a parrot which was the sole living creature that could speak a word of the language of a lost

tribe. Ancient monuments and stone implements found in all parts of the world, about which no tradition has

been preserved by the present inhabitants, indicate much extinction. Some small and broken tribes, remnants

of former races, still survive in isolated and generally mountainous districts. In Europe the ancient races were

all, according to Shaaffhausen (29. Translation in 'Anthropological Review,' Oct. 1868, p. 431.), "lower in the

scale than the rudest living savages"; they must therefore have differed, to a certain extent, from any existing

race. The remains described by Professor Broca from Les Eyzies, though they unfortunately appear to have

belonged to a single family, indicate a race with a most singular combination of low or simious, and of high

characteristics. This race is "entirely different from any other, ancient or modern, that we have heard of." (30.

'Transactions, International Congress of Prehistoric Archaeology' 1868, pp. 172175. See also Broca (tr.) in

'Anthropological Review,' Oct. 1868, p. 410.) It differed, therefore, from the quaternary race of the caverns of

Man can long resist conditions which appear extremely unfavourable for his existence. (31. Dr. Gerland,

'Ueber das Aussterben der Naturvolker,' 1868, s. 82.) He has long lived in the extreme regions of the North,

with no wood for his canoes or implements, and with only blubber as fuel, and melted snow as drink. In the

southern extremity of America the Fuegians survive without the protection of clothes, or of any building

worthy to be called a hovel. In South Africa the aborigines wander over arid plains, where dangerous beasts

abound. Man can withstand the deadly influence of the Terai at the foot of the Himalaya, and the pestilential

Extinction follows chiefly from the competition of tribe with tribe, and race with race. Various checks are

always in action, serving to keep down the numbers of each savage tribe,such as periodical famines,

nomadic habits and the consequent deaths of infants, prolonged suckling, wars, accidents, sickness,

licentiousness, the stealing of women, infanticide, and especially lessened fertility. If any one of these checks

increases in power, even slightly, the tribe thus affected tends to decrease; and when of two adjoining tribes

one becomes less numerous and less powerful than the other, the contest is soon settled by war, slaughter,

cannibalism, slavery, and absorption. Even when a weaker tribe is not thus abruptly swept away, if it once

begins to decrease, it generally goes on decreasing until it becomes extinct. (32. Gerland (ibid. s. 12) gives

When civilised nations come into contact with barbarians the struggle is short, except where a deadly climate

gives its aid to the native race. Of the causes which lead to the victory of civilised nations, some are plain and

simple, others complex and obscure. We can see that the cultivation of the land will be fatal in many ways to

savages, for they cannot, or will not, change their habits. New diseases and vices have in some cases proved

highly destructive; and it appears that a new disease often causes much death, until those who are most

susceptible to its destructive influence are gradually weeded out (33. See remarks to this effect in Sir H.

Holland's 'Medical Notes and Reflections,' 1839, p. 390.); and so it may be with the evil effects from

spirituous liquors, as well as with the unconquerably strong taste for them shewn by so many savages. It

further appears, mysterious as is the fact, that the first meeting of distinct and separated people generates

disease. (34. I have collected ('Journal of Researches: Voyage of the "Beagle,"' p. 435) a good many cases

bearing on this subject; see also Gerland, ibid. s. 8. Poeppig speaks of the "breath of civilisation as poisonous

to savages.") Mr. Sproat, who in Vancouver Island closely attended to the subject of extinction, believed that

changed habits of life, consequent on the advent of Europeans, induces much ill health. He lays, also, great

stress on the apparently trifling cause that the natives become "bewildered and dull by the new life around

them; they lose the motives for exertion, and get no new ones in their place." (35. Sproat, 'Scenes and Studies

The grade of their civilisation seems to be a most important element in the success of competing nations. A

few centuries ago Europe feared the inroads of Eastern barbarians; now any such fear would be ridiculous. It

is a more curious fact, as Mr. Bagehot has remarked, that savages did not formerly waste away before the

classical nations, as they now do before modern civilised nations; had they done so, the old moralists would

have mused over the event; but there is no lament in any writer of that period over the perishing barbarians.

(36. Bagehot, 'Physics and Politics,' 'Fortnightly Review,' April 1, 1868, p. 455.) The most potent of all the

causes of extinction, appears in many cases to be lessened fertility and illhealth, especially amongst the

children, arising from changed conditions of life, notwithstanding that the new conditions may not be

injurious in themselves. I am much indebted to Mr. H.H. Howorth for having called my attention to this

subject, and for having given me information respecting it. I have collected the following cases.

When Tasmania was first colonised the natives were roughly estimated by some at 7000 and by others at

20,000. Their number was soon greatly reduced, chiefly by fighting with the English and with each other.

After the famous hunt by all the colonists, when the remaining natives delivered themselves up to the

government, they consisted only of 120 individuals (37. All the statements here given are taken from 'The

Last of the Tasmanians,' by J. Bonwick, 1870.), who were in 1832 transported to Flinders Island. This island,

situated between Tasmania and Australia, is forty miles long, and from twelve to eighteen miles broad: it

seems healthy, and the natives were well treated. Nevertheless, they suffered greatly in health. In 1834 they

consisted (Bonwick, p. 250) of fortyseven adult males, fortyeight adult females, and sixteen children, or in

all of 111 souls. In 1835 only one hundred were left. As they continued rapidly to decrease, and as they

themselves thought that they should not perish so quickly elsewhere, they were removed in 1847 to Oyster

Cove in the southern part of Tasmania. They then consisted (Dec. 20th, 1847) of fourteen men, twentytwo

women and ten children. (38. This is the statement of the Governor of Tasmania, Sir W. Denison, 'Varieties

of ViceRegal Life,' 1870, vol. i. p. 67.) But the change of site did no good. Disease and death still pursued

them, and in 1864 one man (who died in 1869), and three elderly women alone survived. The infertility of the

women is even a more remarkable fact than the liability of all to illhealth and death. At the time when only

nine women were left at Oyster Cove, they told Mr. Bonwick (p. 386), that only two had ever borne children:

With respect to the cause of this extraordinary state of things, Dr. Story remarks that death followed the

attempts to civilise the natives. "If left to themselves to roam as they were wont and undisturbed, they would

have reared more children, and there would have been less mortality." Another careful observer of the

natives, Mr. Davis, remarks, "The births have been few and the deaths numerous. This may have been in a

great measure owing to their change of living and food; but more so to their banishment from the mainland of

Van Diemen's Land, and consequent depression of spirits" (Bonwick, pp. 388, 390).

Similar facts have been observed in two widely different parts of Australia. The celebrated explorer, Mr.

Gregory, told Mr. Bonwick, that in Queensland "the want of reproduction was being already felt with the

blacks, even in the most recently settled parts, and that decay would set in." Of thirteen aborigines from

Shark's Bay who visited Murchison River, twelve died of consumption within three months. (39. For these

cases, see Bonwick's 'Daily Life of the Tasmanians,' 1870, p. 90: and the 'Last of the Tasmanians,' 1870, p.

The decrease of the Maories of New Zealand has been carefully investigated by Mr. Fenton, in an admirable

Report, from which all the following statements, with one exception, are taken. (40. 'Observations on the

Aboriginal Inhabitants of New Zealand,' published by the Government, 1859.) The decrease in number since

1830 is admitted by every one, including the natives themselves, and is still steadily progressing. Although it

has hitherto been found impossible to take an actual census of the natives, their numbers were carefully

estimated by residents in many districts. The result seems trustworthy, and shows that during the fourteen

years, previous to 1858, the decrease was 19.42 per cent. Some of the tribes, thus carefully examined, lived

above a hundred miles apart, some on the coast, some inland; and their means of subsistence and habits

differed to a certain extent (p. 28). The total number in 1858 was believed to be 53,700, and in 1872, after a

second interval of fourteen years, another census was taken, and the number is given as only 36,359, shewing

a decrease of 32.29 per cent! (41. 'New Zealand,' by Alex. Kennedy, 1873, p. 47.) Mr. Fenton, after shewing

in detail the insufficiency of the various causes, usually assigned in explanation of this extraordinary

decrease, such as new diseases, the profligacy of the women, drunkenness, wars, etc., concludes on weighty

grounds that it depends chiefly on the unproductiveness of the women, and on the extraordinary mortality of

the young children (pp. 31, 34). In proof of this he shews (p. 33) that in 1844 there was one nonadult for

every 2.57 adults; whereas in 1858 there was only one nonadult for every 3.27 adults. The mortality of the

adults is also great. He adduces as a further cause of the decrease the inequality of the sexes; for fewer

females are born than males. To this latter point, depending perhaps on a widely distinct cause, I shall return

in a future chapter. Mr. Fenton contrasts with astonishment the decrease in New Zealand with the increase in

Ireland; countries not very dissimilar in climate, and where the inhabitants now follow nearly similar habits.

The Maories themselves (p. 35) "attribute their decadence, in some measure, to the introduction of new food

and clothing, and the attendant change of habits"; and it will be seen, when we consider the influence of

changed conditions on fertility, that they are probably right. The diminution began between the years 1830

and 1840; and Mr. Fenton shews (p. 40) that about 1830, the art of manufacturing putrid corn (maize), by

long steeping in water, was discovered and largely practised; and this proves that a change of habits was

beginning amongst the natives, even when New Zealand was only thinly inhabited by Europeans. When I

visited the Bay of Islands in 1835, the dress and food of the inhabitants had already been much modified:

they raised potatoes, maize, and other agricultural produce, and exchanged them for English manufactured

It is evident from many statements in the life of Bishop Patteson (42. 'Life of J.C. Patteson,' by C.M. Younge,

1874; see more especially vol. i. p. 530.), that the Melanesians of the New Hebrides and neighbouring

archipelagoes, suffered to an extraordinary degree in health, and perished in large numbers, when they were

removed to New Zealand, Norfolk Island, and other salubrious places, in order to be educated as

The decrease of the native population of the Sandwich Islands is as notorious as that of New Zealand. It has

been roughly estimated by those best capable of judging, that when Cook discovered the Islands in 1779, the

population amounted to about 300,000. According to a loose census in 1823, the numbers then were 142,050.

In 1832, and at several subsequent periods, an accurate census was officially taken, but I have been able to

obtain only the following returns: Native Population Annual rate of decrease per cent., assuming it to (Except

during 1832 and have been uniform between 1836, when the few the successive censuses; foreigners in the

1832 130,313 4.46 1836 108,579 2.47 1853 71,019 0.81 1860 67,084 2.18 1866 58,765 2.17 1872 51,531

We here see that in the interval of forty years, between 1832 and 1872, the population has decreased no less

than sixtyeight per cent.! This has been attributed by most writers to the profligacy of the women, to former

bloody wars, and to the severe labour imposed on conquered tribes and to newly introduced diseases, which

have been on several occasions extremely destructive. No doubt these and other such causes have been highly

efficient, and may account for the extraordinary rate of decrease between the years 1832 and 1836; but the

most potent of all the causes seems to be lessened fertility. According to Dr. Ruschenberger of the U.S. Navy,

who visited these islands between 1835 and 1837, in one district of Hawaii, only twentyfive men out of

1134, and in another district only ten out of 637, had a family with as many as three children. Of eighty

married women, only thirtynine had ever borne children; and "the official report gives an average of half a

child to each married couple in the whole island." This is almost exactly the same average as with the

Tasmanians at Oyster Cove. Jarves, who published his History in 1843, says that "families who have three

children are freed from all taxes; those having more, are rewarded by gifts of land and other

encouragements." This unparalleled enactment by the government well shews how infertile the race had

become. The Rev. A. Bishop stated in the Hawaiian 'Spectator' in 1839, that a large proportion of the children

die at early ages, and Bishop Staley informs me that this is still the case, just as in New Zealand. This has

been attributed to the neglect of the children by the women, but it is probably in large part due to innate

weakness of constitution in the children, in relation to the lessened fertility of their parents. There is,

moreover, a further resemblance to the case of New Zealand, in the fact that there is a large excess of male

over female births: the census of 1872 gives 31,650 males to 25,247 females of all ages, that is 125.36 males

for every 100 females; whereas in all civilised countries the females exceed the males. No doubt the

profligacy of the women may in part account for their small fertility; but their changed habits of life is a

much more probable cause, and which will at the same time account for the increased mortality, especially of

the children. The islands were visited by Cook in 1779, Vancouver in 1794, and often subsequently by

whalers. In 1819 missionaries arrived, and found that idolatry had been already abolished, and other changes

effected by the king. After this period there was a rapid change in almost all the habits of life of the natives,

and they soon became "the most civilised of the Pacific Islanders." One of my informants, Mr. Coan, who

was born on the islands, remarks that the natives have undergone a greater change in their habits of life in the

course of fifty years than Englishmen during a thousand years. From information received from Bishop

Staley, it does not appear that the poorer classes have ever much changed their diet, although many new kinds

of fruit have been introduced, and the sugarcane is in universal use. Owing, however, to their passion for

imitating Europeans, they altered their manner of dressing at an early period, and the use of alcoholic drinks

became very general. Although these changes appear inconsiderable, I can well believe, from what is known

with respect to animals, that they might suffice to lessen the fertility of the natives. (43. The foregoing

statements are taken chiefly from the following works: Jarves' 'History of the Hawaiian Islands,' 1843, pp.

400407. Cheever, 'Life in the Sandwich Islands,' 1851, p. 277. Ruschenberger is quoted by Bonwick, 'Last

of the Tasmanians,' 1870, p. 378. Bishop is quoted by Sir E. Belcher, 'Voyage Round the World,' 1843, vol. i.

p. 272. I owe the census of the several years to the kindness of Mr. Coan, at the request of Dr. Youmans of

New York; and in most cases I have compared the Youmans figures with those given in several of the

abovenamed works. I have omitted the census for 1850, as I have seen two widely different numbers given.)

Lastly, Mr. Macnamara states (44. 'The Indian Medical Gazette,' Nov. 1, 1871, p. 240.) that the low and

degraded inhabitants of the Andaman Islands, on the eastern side of the Gulf of Bengal, are "eminently

susceptible to any change of climate: in fact, take them away from their island homes, and they are almost

certain to die, and that independently of diet or extraneous influences." He further states that the inhabitants

of the Valley of Nepal, which is extremely hot in summer, and also the various hilltribes of India, suffer

from dysentery and fever when on the plains; and they die if they attempt to pass the whole year there.

We thus see that many of the wilder races of man are apt to suffer much in health when subjected to changed

conditions or habits of life, and not exclusively from being transported to a new climate. Mere alterations in

habits, which do not appear injurious in themselves, seem to have this same effect; and in several cases the

children are particularly liable to suffer. It has often been said, as Mr. Macnamara remarks, that man can

resist with impunity the greatest diversities of climate and other changes; but this is true only of the civilised

races. Man in his wild condition seems to be in this respect almost as susceptible as his nearest allies, the

anthropoid apes, which have never yet survived long, when removed from their native country.

Lessened fertility from changed conditions, as in the case of the Tasmanians, Maories, Sandwich Islanders,

and apparently the Australians, is still more interesting than their liability to illhealth and death; for even a

slight degree of infertility, combined with those other causes which tend to check the increase of every

population, would sooner or later lead to extinction. The diminution of fertility may be explained in some

cases by the profligacy of the women (as until lately with the Tahitians), but Mr. Fenton has shewn that this

explanation by no means suffices with the New Zealanders, nor does it with the Tasmanians.

In the paper above quoted, Mr. Macnamara gives reasons for believing that the inhabitants of districts subject

to malaria are apt to be sterile; but this cannot apply in several of the above cases. Some writers have

suggested that the aborigines of islands have suffered in fertility and health from long continued

interbreeding; but in the above cases infertility has coincided too closely with the arrival of Europeans for

us to admit this explanation. Nor have we at present any reason to believe that man is highly sensitive to the

evil effects of interbreeding, especially in areas so large as New Zealand, and the Sandwich archipelago

with its diversified stations. On the contrary, it is known that the present inhabitants of Norfolk Island are

nearly all cousins or near relations, as are the Todas in India, and the inhabitants of some of the Western

Islands of Scotland; and yet they seem not to have suffered in fertility. (45. On the close relationship of the

Norfolk Islanders, Sir W. Denison, 'Varieties of ViceRegal Life,' vol. i. 1870, p. 410. For the Todas, see

Col. Marshall's work 1873, p. 110. For the Western Islands of Scotland, Dr. Mitchell, 'Edinburgh Medical

A much more probable view is suggested by the analogy of the lower animals. The reproductive system can

be shewn to be susceptible to an extraordinary degree (though why we know not) to changed conditions of

life; and this susceptibility leads both to beneficial and to evil results. A large collection of facts on this

subject is given in chap. xviii. of vol. ii. of my 'Variation of Animals and Plants under Domestication,' I can

here give only the briefest abstract; and every one interested in the subject may consult the above work. Very

slight changes increase the health, vigour, and fertility of most or all organic beings, whilst other changes are

known to render a large number of animals sterile. One of the most familiar cases, is that of tamed elephants

not breeding in India; though they often breed in Ava, where the females are allowed to roam about the

forests to some extent, and are thus placed under more natural conditions. The case of various American

monkeys, both sexes of which have been kept for many years together in their own countries, and yet have

very rarely or never bred, is a more apposite instance, because of their relationship to man. It is remarkable

how slight a change in the conditions often induces sterility in a wild animal when captured; and this is the

more strange as all our domesticated animals have become more fertile than they were in a state of nature;

and some of them can resist the most unnatural conditions with undiminished fertility. (46. For the evidence

on this head, see 'Variation of Animals,' etc., vol. ii. p. 111.) Certain groups of animals are much more liable

than others to be affected by captivity; and generally all the species of the same group are affected in the

same manner. But sometimes a single species in a group is rendered sterile, whilst the others are not so; on

the other hand, a single species may retain its fertility whilst most of the others fail to breed. The males and

females of some species when confined, or when allowed to live almost, but not quite free, in their native

country, never unite; others thus circumstanced frequently unite but never produce offspring; others again

produce some offspring, but fewer than in a state of nature; and as bearing on the above cases of man, it is

important to remark that the young are apt to be weak and sickly, or malformed, and to perish at an early age.

Seeing how general is this law of the susceptibility of the reproductive system to changed conditions of life,

and that it holds good with our nearest allies, the Quadrumana, I can hardly doubt that it applies to man in his

primeval state. Hence if savages of any race are induced suddenly to change their habits of life, they become

more or less sterile, and their young offspring suffer in health, in the same manner and from the same cause,

as do the elephant and huntingleopard in India, many monkeys in America, and a host of animals of all

We can see why it is that aborigines, who have long inhabited islands, and who must have been long exposed

to nearly uniform conditions, should be specially affected by any change in their habits, as seems to be the

case. Civilised races can certainly resist changes of all kinds far better than savages; and in this respect they

resemble domesticated animals, for though the latter sometimes suffer in health (for instance European dogs

in India), yet they are rarely rendered sterile, though a few such instances have been recorded. (47. 'Variation

of Animals,' etc., vol. ii. p. 16.) The immunity of civilised races and domesticated animals is probably due to

their having been subjected to a greater extent, and therefore having grown somewhat more accustomed, to

diversified or varying conditions, than the majority of wild animals; and to their having formerly immigrated

or been carried from country to country, and to different families or subraces having intercrossed. It

appears that a cross with civilised races at once gives to an aboriginal race an immunity from the evil

consequences of changed conditions. Thus the crossed offspring from the Tahitians and English, when settled

in Pitcairn Island, increased so rapidly that the island was soon overstocked; and in June 1856 they were

removed to Norfolk Island. They then consisted of 60 married persons and 134 children, making a total of

194. Here they likewise increased so rapidly, that although sixteen of them returned to Pitcairn Island in

1859, they numbered in January 1868, 300 souls; the males and females being in exactly equal numbers.

What a contrast does this case present with that of the Tasmanians; the Norfolk Islanders INCREASED in

only twelve and a half years from 194 to 300; whereas the Tasmanians DECREASED during fifteen years

from 120 to 46, of which latter number only ten were children. (48. These details are taken from 'The

Mutineers of the "Bounty,"' by Lady Belcher, 1870; and from 'Pitcairn Island,' ordered to be printed by the

House of Commons, May 29, 1863. The following statements about the Sandwich Islanders are from the

So again in the interval between the census of 1866 and 1872 the natives of full blood in the Sandwich

Islands decreased by 8081, whilst the half castes, who are believed to be healthier, increased by 847; but I

do not know whether the latter number includes the offspring from the halfcastes, or only the halfcastes of

The cases which I have here given all relate to aborigines, who have been subjected to new conditions as the

result of the immigration of civilised men. But sterility and illhealth would probably follow, if savages were

compelled by any cause, such as the inroad of a conquering tribe, to desert their homes and to change their

habits. It is an interesting circumstance that the chief check to wild animals becoming domesticated, which

implies the power of their breeding freely when first captured, and one chief check to wild men, when

brought into contact with civilisation, surviving to form a civilised race, is the same, namely, sterility from

Finally, although the gradual decrease and ultimate extinction of the races of man is a highly complex

problem, depending on many causes which differ in different places and at different times; it is the same

problem as that presented by the extinction of one of the higher animalsof the fossil horse, for instance,

which disappeared from South America, soon afterwards to be replaced, within the same districts, by

countless troups of the Spanish horse. The New Zealander seems conscious of this parallelism, for he

compares his future fate with that of the native rat now almost exterminated by the European rat. Though the

difficulty is great to our imagination, and really great, if we wish to ascertain the precise causes and their

manner of action, it ought not to be so to our reason, as long as we keep steadily in mind that the increase of

each species and each race is constantly checked in various ways; so that if any new check, even a slight one,

be superadded, the race will surely decrease in number; and decreasing numbers will sooner or later lead to

extinction; the end, in most cases, being promptly determined by the inroads of conquering tribes.

In some cases the crossing of distinct races has led to the formation of a new race. The singular fact that the

Europeans and Hindoos, who belong to the same Aryan stock, and speak a language fundamentally the same,

differ widely in appearance, whilst Europeans differ but little from Jews, who belong to the Semitic stock,

and speak quite another language, has been accounted for by Broca (49. 'On Anthropology,' translation,

'Anthropological Review,' Jan. 1868, p. 38.), through certain Aryan branches having been largely crossed by

indigenous tribes during their wide diffusion. When two races in close contact cross, the first result is a

heterogeneous mixture: thus Mr. Hunter, in describing the Santali or hill tribes of India, says that hundreds

of imperceptible gradations may be traced "from the black, squat tribes of the mountains to the tall olive

coloured Brahman, with his intellectual brow, calm eyes, and high but narrow head"; so that it is necessary in

courts of justice to ask the witnesses whether they are Santalis or Hindoos. (50. 'The Annals of Rural Bengal,'

1868, p. 134.) Whether a heterogeneous people, such as the inhabitants of some of the Polynesian islands,

formed by the crossing of two distinct races, with few or no pure members left, would ever become

homogeneous, is not known from direct evidence. But as with our domesticated animals, a crossbreed can

certainly be fixed and made uniform by careful selection (51. 'The Variation of Animals and Plants under

Domestication,' vol. ii. p. 95.) in the course of a few generations, we may infer that the free intercrossing of a

heterogeneous mixture during a long descent would supply the place of selection, and overcome any

tendency to reversion; so that the crossed race would ultimately become homogeneous, though it might not

Of all the differences between the races of man, the colour of the skin is the most conspicuous and one of the

best marked. It was formerly thought that differences of this kind could be accounted for by long exposure to

different climates; but Pallas first shewed that this is not tenable, and he has since been followed by almost all

anthropologists. (52. Pallas, 'Act. Acad. St. Petersburg,' 1780, part ii. p. 69. He was followed by Rudolphi, in

his 'Beytrage zur Anthropologie,' 1812. An excellent summary of the evidence is given by Godron, 'De

l'Espece,' 1859, vol. ii. p. 246, etc.) This view has been rejected chiefly because the distribution of the

variously coloured races, most of whom must have long inhabited their present homes, does not coincide with

corresponding differences of climate. Some little weight may be given to such cases as that of the Dutch

families, who, as we hear on excellent authority (53. Sir Andrew Smith, as quoted by Knox, 'Races of Man,'

1850, p. 473.), have not undergone the least change of colour after residing for three centuries in South

Africa. An argument on the same side may likewise be drawn from the uniform appearance in various parts

of the world of gipsies and Jews, though the uniformity of the latter has been somewhat exaggerated. (54. See

De Quatrefages on this head, 'Revue des Cours Scientifiques,' Oct. 17, 1868, p. 731.) A very damp or a very

dry atmosphere has been supposed to be more influential in modifying the colour of the skin than mere heat;

but as D'Orbigny in South America, and Livingstone in Africa, arrived at diametrically opposite conclusions

with respect to dampness and dryness, any conclusion on this head must be considered as very doubtful. (55.

Livingstone's 'Travels and Researches in S. Africa,' 1857, pp. 338, 339. D'Orbigny, as quoted by Godron, 'De

Various facts, which I have given elsewhere, prove that the colour of the skin and hair is sometimes

correlated in a surprising manner with a complete immunity from the action of certain vegetable poisons, and

from the attacks of certain parasites. Hence it occurred to me, that negroes and other dark races might have

acquired their dark tints by the darker individuals escaping from the deadly influence of the miasma of their

I afterwards found that this same idea had long ago occurred to Dr. Wells. (56. See a paper read before the

Royal Soc. in 1813, and published in his Essays in 1818. I have given an account of Dr. Wells' views in the

Historical Sketch (p. xvi.) to my 'Origin of Species.' Various cases of colour correlated with constitutional

peculiarities are given in my 'Variation of Animals and Plants under Domestication,' vol. ii. pp. 227, 335.) It

has long been known that negroes, and even mulattoes, are almost completely exempt from the yellowfever,

so destructive in tropical America. (57. See, for instance, Nott and Gliddon, 'Types of Mankind,' p. 68.) They

likewise escape to a large extent the fatal intermittent fevers, that prevail along at least 2600 miles of the

shores of Africa, and which annually cause onefifth of the white settlers to die, and another fifth to return

home invalided. (58. Major Tulloch, in a paper read before the Statistical Society, April 20, 1840, and given

in the 'Athenaeum,' 1840, p. 353.) This immunity in the negro seems to be partly inherent, depending on

some unknown peculiarity of constitution, and partly the result of acclimatisation. Pouchet (59. 'The Plurality

of the Human Race' (translat.), 1864, p. 60.) states that the negro regiments recruited near the Soudan, and

borrowed from the Viceroy of Egypt for the Mexican war, escaped the yellowfever almost equally with the

negroes originally brought from various parts of Africa and accustomed to the climate of the West Indies.

That acclimatisation plays a part, is shewn by the many cases in which negroes have become somewhat liable

to tropical fevers, after having resided for some time in a colder climate. (60. Quatrefages, 'Unite de l'Espece

Humaine,' 1861, p. 205. Waitz, 'Introduction to Anthropology,' translat., vol. i. 1863, p. 124. Livingstone

gives analogous cases in his 'Travels.') The nature of the climate under which the white races have long

resided, likewise has some influence on them; for during the fearful epidemic of yellow fever in Demerara

during 1837, Dr. Blair found that the deathrate of the immigrants was proportional to the latitude of the

country whence they had come. With the negro the immunity, as far as it is the result of acclimatisation,

implies exposure during a prodigious length of time; for the aborigines of tropical America who have resided

there from time immemorial, are not exempt from yellow fever; and the Rev. H.B. Tristram states, that there

are districts in Northern Africa which the native inhabitants are compelled annually to leave, though the

That the immunity of the negro is in any degree correlated with the colour of his skin is a mere conjecture: it

may be correlated with some difference in his blood, nervous system, or other tissues. Nevertheless, from the

facts above alluded to, and from some connection apparently existing between complexion and a tendency to

consumption, the conjecture seemed to me not improbable. Consequently I endeavoured, with but little

success (61. In the spring of 1862 I obtained permission from the DirectorGeneral of the Medical

department of the Army, to transmit to the surgeons of the various regiments on foreign service a blank table,

with the following appended remarks, but I have received no returns. "As several wellmarked cases have

been recorded with our domestic animals of a relation between the colour of the dermal appendages and the

constitution; and it being notorious that there is some limited degree of relation between the colour of the

races of man and the climate inhabited by them; the following investigation seems worth consideration.

Namely, whether there is any relation in Europeans between the colour of their hair, and their liability to the

diseases of tropical countries. If the surgeons of the several regiments, when stationed in unhealthy tropical

districts, would be so good as first to count, as a standard of comparison, how many men, in the force whence

the sick are drawn, have dark and lightcoloured hair, and hair of intermediate or doubtful tints; and if a

similar account were kept by the same medical gentlemen, of all the men who suffered from malarious and

yellow fevers, or from dysentery, it would soon be apparent, after some thousand cases had been tabulated,

whether there exists any relation between the colour of the hair and constitutional liability to tropical

diseases. Perhaps no such relation would be discovered, but the investigation is well worth making. In case

any positive result were obtained, it might be of some practical use in selecting men for any particular

service. Theoretically the result would be of high interest, as indicating one means by which a race of men

inhabiting from a remote period an unhealthy tropical climate, might have become darkcoloured by the

better preservation of darkhaired or darkcomplexioned individuals during a long succession of

generations."), to ascertain how far it holds good. The late Dr. Daniell, who had long lived on the West Coast

of Africa, told me that he did not believe in any such relation. He was himself unusually fair, and had

withstood the climate in a wonderful manner. When he first arrived as a boy on the coast, an old and

experienced negro chief predicted from his appearance that this would prove the case. Dr. Nicholson, of

Antigua, after having attended to this subject, writes to me that dark coloured Europeans escape the yellow

fever more than those that are light coloured. Mr. J.M. Harris altogether denies that Europeans with dark

hair withstand a hot climate better than other men: on the contrary, experience has taught him in making a

selection of men for service on the coast of Africa, to choose those with red hair. (62. 'Anthropological

Review,' Jan. 1866, p. xxi. Dr. Sharpe also says, with respect to India ('Man a Special Creation,' 1873, p.

118), "that it has been noticed by some medical officers that Europeans with light hair and florid complexions

suffer less from diseases of tropical countries than persons with dark hair and sallow complexions; and, so far

as I know, there appear to be good grounds for this remark." On the other hand, Mr. Heddle, of Sierra Leone,

"who has had more clerks killed under him than any other man," by the climate of the West African Coast

(W. Reade, 'African Sketch Book,' vol. ii. p. 522), holds a directly opposite view, as does Capt. Burton.) As

far, therefore, as these slight indications go, there seems no foundation for the hypothesis, that blackness has

resulted from the darker and darker individuals having survived better during long exposure to

Dr. Sharpe remarks (63. 'Man a Special Creation,' 1873, p. 119.), that a tropical sun, which burns and blisters

a white skin, does not injure a black one at all; and, as he adds, this is not due to habit in the individual, for

children only six or eight months old are often carried about naked, and are not affected. I have been assured

by a medical man, that some years ago during each summer, but not during the winter, his hands became

marked with light brown patches, like, although larger than freckles, and that these patches were never

affected by sunburning, whilst the white parts of his skin have on several occasions been much inflamed and

blistered. With the lower animals there is, also, a constitutional difference in liability to the action of the sun

between those parts of the skin clothed with white hair and other parts. (64. 'Variation of Animals and Plants

under Domestication,' vol. ii. pp. 336, 337.) Whether the saving of the skin from being thus burnt is of

sufficient importance to account for a dark tint having been gradually acquired by man through natural

selection, I am unable to judge. If it be so, we should have to assume that the natives of tropical America

have lived there for a much shorter time than the Negroes in Africa, or the Papuans in the southern parts of

the Malay archipelago, just as the lightercoloured Hindoos have resided in India for a shorter time than the

Although with our present knowledge we cannot account for the differences of colour in the races of man,

through any advantage thus gained, or from the direct action of climate; yet we must not quite ignore the

latter agency, for there is good reason to believe that some inherited effect is thus produced. (65. See, for

instance, Quatrefages ('Revue des Cours Scientifiques,' Oct. 10, 1868, p. 724) on the effects of residence in

Abyssinia and Arabia, and other analogous cases. Dr. Rolle ('Der Mensch, seine Abstammung,' etc., 1865, s.

99) states, on the authority of Khanikof, that the greater number of German families settled in Georgia, have

acquired in the course of two generations dark hair and eyes. Mr. D. Forbes informs me that the Quichuas in

the Andes vary greatly in colour, according to the position of the valleys inhabited by them.)

We have seen in the second chapter that the conditions of life affect the development of the bodily frame in a

direct manner, and that the effects are transmitted. Thus, as is generally admitted, the European settlers in the

United States undergo a slight but extraordinary rapid change of appearance. Their bodies and limbs become

elongated; and I hear from Col. Bernys that during the late war in the United States, good evidence was

afforded of this fact by the ridiculous appearance presented by the German regiments, when dressed in

readymade clothes manufactured for the American market, and which were much too long for the men in

every way. There is, also, a considerable body of evidence shewing that in the Southern States the

houseslaves of the third generation present a markedly different appearance from the fieldslaves. (66.

Harlan, 'Medical Researches,' p. 532. Quatrefages ('Unite de l'Espece Humaine,' 1861, p. 128) has collected

If, however, we look to the races of man as distributed over the world, we must infer that their characteristic

differences cannot be accounted for by the direct action of different conditions of life, even after exposure to

them for an enormous period of time. The Esquimaux live exclusively on animal food; they are clothed in

thick fur, and are exposed to intense cold and to prolonged darkness; yet they do not differ in any extreme

degree from the inhabitants of Southern China, who live entirely on vegetable food, and are exposed almost

naked to a hot, glaring climate. The unclothed Fuegians live on the marine productions of their inhospitable

shores; the Botocudos of Brazil wander about the hot forests of the interior and live chiefly on vegetable

productions; yet these tribes resemble each other so closely that the Fuegians on board the "Beagle" were

mistaken by some Brazilians for Botocudos. The Botocudos again, as well as the other inhabitants of tropical

America, are wholly different from the Negroes who inhabit the opposite shores of the Atlantic, are exposed

Nor can the differences between the races of man be accounted for by the inherited effects of the increased or

decreased use of parts, except to a quite insignificant degree. Men who habitually live in canoes, may have

their legs somewhat stunted; those who inhabit lofty regions may have their chests enlarged; and those who

constantly use certain senseorgans may have the cavities in which they are lodged somewhat increased in

size, and their features consequently a little modified. With civilised nations, the reduced size of the jaws

from lessened usethe habitual play of different muscles serving to express different emotionsand the

increased size of the brain from greater intellectual activity, have together produced a considerable effect on

their general appearance when compared with savages. (67. See Prof. Schaaffhausen, translat., in

'Anthropological Review,' Oct. 1868, p. 429.) Increased bodily stature, without any corresponding increase in

the size of the brain, may (judging from the previously adduced case of rabbits), have given to some races an

Lastly, the littleunderstood principle of correlated development has sometimes come into action, as in the

case of great muscular development and strongly projecting supraorbital ridges. The colour of the skin and

hair are plainly correlated, as is the texture of the hair with its colour in the Mandans of North America. (68.

Mr. Catlin states ('N. American Indians,' 3rd ed., 1842, vol. i. p. 49) that in the whole tribe of the Mandans,

about one in ten or twelve of the members, of all ages and both sexes, have bright silvery grey hair, which is

hereditary. Now this hair is as coarse and harsh as that of a horse's mane, whilst the hair of other colours is

fine and soft.) The colour also of the skin, and the odour emitted by it, are likewise in some manner

connected. With the breeds of sheep the number of hairs within a given space and the number of excretory

pores are related. (69. On the odour of the skin, Godron, 'Sur l'Espece,' tom. ii. p. 217. On the pores in the

skin, Dr. Wilckens, 'Die Aufgaben der Landwirth. Zootechnik,' 1869, s. 7.) If we may judge from the analogy

of our domesticated animals, many modifications of structure in man probably come under this principle of

We have now seen that the external characteristic differences between the races of man cannot be accounted

for in a satisfactory manner by the direct action of the conditions of life, nor by the effects of the continued

use of parts, nor through the principle of correlation. We are therefore led to enquire whether slight individual

differences, to which man is eminently liable, may not have been preserved and augmented during a long

series of generations through natural selection. But here we are at once met by the objection that beneficial

variations alone can be thus preserved; and as far as we are enabled to judge, although always liable to err on

this head, none of the differences between the races of man are of any direct or special service to him. The

intellectual and moral or social faculties must of course be excepted from this remark. The great variability of

all the external differences between the races of man, likewise indicates that they cannot be of much

importance; for if important, they would long ago have been either fixed and preserved, or eliminated. In this

respect man resembles those forms, called by naturalists protean or polymorphic, which have remained

extremely variable, owing, as it seems, to such variations being of an indifferent nature, and to their having

We have thus far been baffled in all our attempts to account for the differences between the races of man; but

there remains one important agency, namely Sexual Selection, which appears to have acted powerfully on

man, as on many other animals. I do not intend to assert that sexual selection will account for all the

differences between the races. An unexplained residuum is left, about which we can only say, in our

ignorance, that as individuals are continually born with, for instance, heads a little rounder or narrower, and

with noses a little longer or shorter, such slight differences might become fixed and uniform, if the unknown

agencies which induced them were to act in a more constant manner, aided by longcontinued intercrossing.

Such variations come under the provisional class, alluded to in our second chapter, which for want of a better

term are often called spontaneous. Nor do I pretend that the effects of sexual selection can be indicated with

scientific precision; but it can be shewn that it would be an inexplicable fact if man had not been modified by

this agency, which appears to have acted powerfully on innumerable animals. It can further be shewn that the

differences between the races of man, as in colour, hairiness, form of features, etc., are of a kind which might

have been expected to come under the influence of sexual selection. But in order to treat this subject properly,

I have found it necessary to pass the whole animal kingdom in review. I have therefore devoted to it the

Second Part of this work. At the close I shall return to man, and, after attempting to shew how far he has been

modified through sexual selection, will give a brief summary of the chapters in this First Part.

The controversy respecting the nature and the extent of the differences in the structure of the brain in man and

the apes, which arose some fifteen years ago, has not yet come to an end, though the subject matter of the

dispute is, at present, totally different from what it was formerly. It was originally asserted and reasserted,

with singular pertinacity, that the brain of all the apes, even the highest, differs from that of man, in the

absence of such conspicuous structures as the posterior lobes of the cerebral hemispheres, with the posterior

cornu of the lateral ventricle and the hippocampus minor, contained in those lobes, which are so obvious in

But the truth that the three structures in question are as well developed in apes' as in human brains, or even

better; and that it is characteristic of all the Primates (if we exclude the Lemurs) to have these parts well

developed, stands at present on as secure a basis as any proposition in comparative anatomy. Moreover, it is

admitted by every one of the long series of anatomists who, of late years, have paid special attention to the

arrangement of the complicated sulci and gyri which appear upon the surface of the cerebral hemispheres in

man and the higher apes, that they are disposed after the very same pattern in him, as in them. Every principal

gyrus and sulcus of a chimpanzee's brain is clearly represented in that of a man, so that the terminology

which applies to the one answers for the other. On this point there is no difference of opinion. Some years

since, Professor Bischoff published a memoir (70. 'Die GrosshirnWindungen des Menschen;'

'Abhandlungen der K. Bayerischen Akademie,' B. x. 1868.) on the cerebral convolutions of man and apes;

and as the purpose of my learned colleague was certainly not to diminish the value of the differences between

"That the apes, and especially the orang, chimpanzee and gorilla, come very close to man in their

organisation, much nearer than to any other animal, is a well known fact, disputed by nobody. Looking at the

matter from the point of view of organisation alone, no one probably would ever have disputed the view of

Linnaeus, that man should be placed, merely as a peculiar species, at the head of the mammalia and of those

apes. Both shew, in all their organs, so close an affinity, that the most exact anatomical investigation is

needed in order to demonstrate those differences which really exist. So it is with the brains. The brains of

man, the orang, the chimpanzee, the gorilla, in spite of all the important differences which they present, come

There remains, then, no dispute as to the resemblance in fundamental characters, between the ape's brain and

man's: nor any as to the wonderfully close similarity between the chimpanzee, orang and man, in even the

details of the arrangement of the gyri and sulci of the cerebral hemispheres. Nor, turning to the differences

between the brains of the highest apes and that of man, is there any serious question as to the nature and

extent of these differences. It is admitted that the man's cerebral hemispheres are absolutely and relatively

larger than those of the orang and chimpanzee; that his frontal lobes are less excavated by the upward

protrusion of the roof of the orbits; that his gyri and sulci are, as a rule, less symmetrically disposed, and

present a greater number of secondary plications. And it is admitted that, as a rule, in man, the

temporooccipital or "external perpendicular" fissure, which is usually so strongly marked a feature of the

ape's brain is but faintly marked. But it is also clear, that none of these differences constitutes a sharp

demarcation between the man's and the ape's brain. In respect to the external perpendicular fissure of

Gratiolet, in the human brain for instance, Professor Turner remarks: (71. 'Convolutions of the Human

"In some brains it appears simply as an indentation of the margin of the hemisphere, but, in others, it extends

for some distance more or less transversely outwards. I saw it in the right hemisphere of a female brain pass

more than two inches outwards; and on another specimen, also the right hemisphere, it proceeded for

fourtenths of an inch outwards, and then extended downwards, as far as the lower margin of the outer

surface of the hemisphere. The imperfect definition of this fissure in the majority of human brains, as

compared with its remarkable distinctness in the brain of most Quadrumana, is owing to the presence, in the

former, of certain superficial, well marked, secondary convolutions which bridge it over and connect the

parietal with the occipital lobe. The closer the first of these bridging gyri lies to the longitudinal fissure, the

The obliteration of the external perpendicular fissure of Gratiolet, therefore, is not a constant character of the

human brain. On the other hand, its full development is not a constant character of the higher ape's brain. For,

in the chimpanzee, the more or less extensive obliteration of the external perpendicular sulcus by "bridging

convolutions," on one side or the other, has been noted over and over again by Prof. Rolleston, Mr. Marshall,

M. Broca and Professor Turner. At the conclusion of a special paper on this subject the latter writes: (72.

Notes more especially on the bridging convolutions in the Brain of the Chimpanzee, 'Proceedings of the

"The three specimens of the brain of a chimpanzee, just described, prove, that the generalisation which

Gratiolet has attempted to draw of the complete absence of the first connecting convolution and the

concealment of the second, as essentially characteristic features in the brain of this animal, is by no means

universally applicable. In only one specimen did the brain, in these particulars, follow the law which Gratiolet

has expressed. As regards the presence of the superior bridging convolution, I am inclined to think that it has

existed in one hemisphere, at least, in a majority of the brains of this animal which have, up to this time, been

figured or described. The superficial position of the second bridging convolution is evidently less frequent,

and has as yet, I believe, only been seen in the brain (A) recorded in this communication. The asymmetrical

arrangement in the convolutions of the two hemispheres, which previous observers have referred to in their

Even were the presence of the temporooccipital, or external perpendicular, sulcus, a mark of distinction

between the higher apes and man, the value of such a distinctive character would be rendered very doubtful

by the structure of the brain in the Platyrrhine apes. In fact, while the temporooccipital is one of the most

constant of sulci in the Catarrhine, or Old World, apes, it is never very strongly developed in the New World

apes; it is absent in the smaller Platyrrhini; rudimentary in Pithecia (73. Flower, 'On the Anatomy of Pithecia

Monachus,' 'Proceedings of the Zoological Society,' 1862.); and more or less obliterated by bridging

A character which is thus variable within the limits of a single group can have no great taxonomic value.

It is further established, that the degree of asymmetry of the convolution of the two sides in the human brain

is subject to much individual variation; and that, in those individuals of the Bushman race who have been

examined, the gyri and sulci of the two hemispheres are considerably less complicated and more symmetrical

than in the European brain, while, in some individuals of the chimpanzee, their complexity and asymmetry

become notable. This is particularly the case in the brain of a young male chimpanzee figured by M. Broca.

Again, as respects the question of absolute size, it is established that the difference between the largest and

the smallest healthy human brain is greater than the difference between the smallest healthy human brain and

Moreover, there is one circumstance in which the orang's and chimpanzee's brains resemble man's, but in

which they differ from the lower apes, and that is the presence of two corpora candicantiathe Cynomorpha

In view of these facts I do not hesitate in this year 1874, to repeat and insist upon the proposition which I

"So far as cerebral structure goes, therefore, it is clear that man differs less from the chimpanzee or the orang,

than these do even from the monkeys, and that the difference between the brain of the chimpanzee and of

man is almost insignificant when compared with that between the chimpanzee brain and that of a Lemur."

In the paper to which I have referred, Professor Bischoff does not deny the second part of this statement, but

he first makes the irrelevant remark that it is not wonderful if the brains of an orang and a Lemur are very

different; and secondly, goes on to assert that, "If we successively compare the brain of a man with that of an

orang; the brain of this with that of a chimpanzee; of this with that of a gorilla, and so on of a Hylobates,

Semnopithecus, Cynocephalus, Cercopithecus, Macacus, Cebus, Callithrix, Lemur, Stenops, Hapale, we shall

not meet with a greater, or even as great a, break in the degree of development of the convolutions, as we find

To which I reply, firstly, that whether this assertion be true or false, it has nothing whatever to do with the

proposition enunciated in 'Man's Place in Nature,' which refers not to the development of the convolutions

alone, but to the structure of the whole brain. If Professor Bischoff had taken the trouble to refer to p. 96 of

the work he criticises, in fact, he would have found the following passage: "And it is a remarkable

circumstance that though, so far as our present knowledge extends, there IS one true structural break in the

series of forms of Simian brains, this hiatus does not lie between man and the manlike apes, but between the

lower and the lowest Simians, or in other words, between the Old and New World apes and monkeys and the

Lemurs. Every Lemur which has yet been examined, in fact, has its cerebellum partially visible from above;

and its posterior lobe, with the contained posterior cornu and hippocampus minor, more or less rudimentary.

Every marmoset, American monkey, Old World monkey, baboon or manlike ape, on the contrary, has its

cerebellum entirely hidden, posteriorly, by the cerebral lobes, and possesses a large posterior cornu with a

This statement was a strictly accurate account of what was known when it was made; and it does not appear

to me to be more than apparently weakened by the subsequent discovery of the relatively small development

of the posterior lobes in the Siamang and in the Howling monkey. Notwithstanding the exceptional brevity of

the posterior lobes in these two species, no one will pretend that their brains, in the slightest degree, approach

those of the Lemurs. And if, instead of putting Hapale out of its natural place, as Professor Bischoff most

unaccountably does, we write the series of animals he has chosen to mention as follows: Homo, Pithecus,

Troglodytes, Hylobates, Semnopithecus, Cynocephalus, Cercopithecus, Macacus, Cebus, Callithrix, Hapale,

Lemur, Stenops, I venture to reaffirm that the great break in this series lies between Hapale and Lemur, and

that this break is considerably greater than that between any other two terms of that series. Professor Bischoff

ignores the fact that long before he wrote, Gratiolet had suggested the separation of the Lemurs from the

other Primates on the very ground of the difference in their cerebral characters; and that Professor Flower had

made the following observations in the course of his description of the brain of the Javan Loris: (75.

"And it is especially remarkable that, in the development of the posterior lobes, there is no approximation to

the Lemurine, short hemisphered brain, in those monkeys which are commonly supposed to approach this

So far as the structure of the adult brain is concerned, then, the very considerable additions to our knowledge,

which have been made by the researches of so many investigators, during the past ten years, fully justify the

statement which I made in 1863. But it has been said, that, admitting the similarity between the adult brains

of man and apes, they are nevertheless, in reality, widely different, because they exhibit fundamental

differences in the mode of their development. No one would be more ready than I to admit the force of this

argument, if such fundamental differences of development really exist. But I deny that they do exist. On the

contrary, there is a fundamental agreement in the development of the brain in men and apes.

Gratiolet originated the statement that there is a fundamental difference in the development of the brains of

apes and that of manconsisting in this; that, in the apes, the sulci which first make their appearance are

situated on the posterior region of the cerebral hemispheres, while, in the human foetus, the sulci first become

visible on the frontal lobes. (76. "Chez tous les singes, les plis posterieurs se developpent les premiers; les

plis anterieurs se developpent plus tard, aussi la vertebre occipitale et la parietale sontelles relativement

tresgrandes chez le foetus. L'Homme presente une exception remarquable quant a l'epoque de l'apparition

des plis frontaux, qui sont les premiers indiques; mais le developpement general du lobe frontal, envisage

seulement par rapport a son volume, suit les memes lois que dans les singes:" Gratiolet, 'Memoire sur les plis

This general statement is based upon two observations, the one of a Gibbon almost ready to be born, in which

the posterior gyri were "well developed," while those of the frontal lobes were "hardly indicated" (77.

Gratiolet's words are (loc. cit. p. 39): "Dans le foetus dont il s'agit les plis cerebraux posterieurs sont bien

developpes, tandis que les plis du lobe frontal sont a peine indiques." The figure, however (Pl. iv, fig. 3),

shews the fissure of Rolando, and one of the frontal sulci plainly enough. Nevertheless, M. Alix, in his

'Notice sur les travaux anthropologiques de Gratiolet' ('Mem. de la Societe d'Anthropologie de Paris,' 1868,

page 32), writes thus: "Gratiolet a eu entre les mains le cerveau d'un foetus de Gibbon, singe eminemment

superieur, et tellement rapproche de l'orang, que des naturalistes trescompetents l'ont range parmi les

anthropoides. M. Huxley, par exemple, n'hesite pas sur ce point. Eh bien, c'est sur le cerveau d'un foetus de

DEVELOPPEES LORSQU'IL N'EXISTENT PAS ENCORE DE PLIS SUR LE LOBE FRONTAL. Il etait

donc bien autorise a dire que, chez l'homme les circonvolutions apparaissent d'a en w, tandis que chez les

singes elles se developpent d'w en a."), and the other of a human foetus at the 22nd or 23rd week of

uterogestation, in which Gratiolet notes that the insula was uncovered, but that nevertheless "des incisures

sement de lobe anterieur, une scissure peu profonde indique la separation du lobe occipital, tresreduit,

d'ailleurs des cette epoque. Le reste de la surface cerebrale est encore absolument lisse."

Three views of this brain are given in Plate II, figs. 1, 2, 3, of the work cited, shewing the upper, lateral and

inferior views of the hemispheres, but not the inner view. It is worthy of note that the figure by no means

bears out Gratiolet's description, inasmuch as the fissure (antero temporal) on the posterior half of the face

of the hemisphere is more marked than any of those vaguely indicated in the anterior half. If the figure is

correct, it in no way justifies Gratiolet's conclusion: "Il y a donc entre ces cerveaux [those of a Callithrix and

of a Gibbon] et celui du foetus humain une difference fondamental. Chez celuici, longtemps avant que les

Since Gratiolet's time, however, the development of the gyri and sulci of the brain has been made the subject

of renewed investigation by Schmidt, Bischoff, Pansch (78. 'Ueber die typische Anordnung der Furchen und

Windungen auf den GrosshirnHemispharen des Menschen und der Affen,' 'Archiv fur Anthropologie,' iii.

1868.), and more particularly by Ecker (79. 'Zur Entwicklungs Geschichte der Furchen und Windungen der

Grosshirn Hemispharen im Foetus des Menschen.' 'Archiv fur Anthropologie,' iii. 1868.), whose work is not

1. In the human foetus, the sylvian fissure is formed in the course of the third month of uterogestation. In this,

and in the fourth month, the cerebral hemispheres are smooth and rounded (with the exception of the sylvian

2. The sulci, properly so called, begin to appear in the interval between the end of the fourth and the

beginning of the sixth month of foetal life, but Ecker is careful to point out that, not only the time, but the

order, of their appearance is subject to considerable individual variation. In no case, however, are either the

The first which appears, in fact, lies on the inner face of the hemisphere (whence doubtless Gratiolet, who

does not seem to have examined that face in his foetus, overlooked it), and is either the internal perpendicular

(occipitoparietal), or the calcarine sulcus, these two being close together and eventually running into one

3. At the latter part of this period, another sulcus, the "posterio parietal," or "Fissure of Rolando" is

developed, and it is followed, in the course of the sixth month, by the other principal sulci of the frontal,

parietal, temporal and occipital lobes. There is, however, no clear evidence that one of these constantly

appears before the other; and it is remarkable that, in the brain at the period described and figured by Ecker

(loc. cit. pp. 212213, Taf. II, figs. 1, 2, 3, 4), the anterotemporal sulcus (scissure parallele) so characteristic

of the ape's brain, is as well, if not better developed than the fissure of Rolando, and is much more marked

Taking the facts as they now stand, it appears to me that the order of the appearance of the sulci and gyri in

the foetal human brain is in perfect harmony with the general doctrine of evolution, and with the view that

man has been evolved from some apelike form; though there can be no doubt that form was, in many

Von Baer taught us, half a century ago, that, in the course of their development, allied animals put on at first,

the characters of the greater groups to which they belong, and, by degrees, assume those which restrict them

within the limits of their family, genus, and species; and he proved, at the same time, that no developmental

stage of a higher animal is precisely similar to the adult condition of any lower animal. It is quite correct to

say that a frog passes through the condition of a fish, inasmuch as at one period of its life the tadpole has all

the characters of a fish, and if it went no further, would have to be grouped among fishes. But it is equally

In like manner, the brain of a human foetus, at the fifth month, may correctly be said to be, not only the brain

of an ape, but that of an Arctopithecine or marmosetlike ape; for its hemispheres, with their great posterior

lobster, and with no sulci but the sylvian and the calcarine, present the characteristics found only in the group

of the Arctopithecine Primates. But it is equally true, as Gratiolet remarks, that, in its widely open sylvian

fissure, it differs from the brain of any actual marmoset. No doubt it would be much more similar to the brain

of an advanced foetus of a marmoset. But we know nothing whatever of the development of the brain in the

marmosets. In the Platyrrhini proper, the only observation with which I am acquainted is due to Pansch, who

found in the brain of a foetal Cebus Apella, in addition to the sylvian fissure and the deep calcarine fissure,

Now this fact, taken together with the circumstance that the antero temporal sulcus is present in such

Platyrrhini as the Saimiri, which present mere traces of sulci on the anterior half of the exterior of the cerebral

hemispheres, or none at all, undoubtedly, so far as it goes, affords fair evidence in favour of Gratiolet's

hypothesis, that the posterior sulci appear before the anterior, in the brains of the Platyrrhini. But, it by no

means follows, that the rule which may hold good for the Platyrrhini extends to the Catarrhini. We have no

information whatever respecting the development of the brain in the Cynomorpha; and, as regards the

Anthropomorpha, nothing but the account of the brain of the Gibbon, near birth, already referred to. At the

present moment there is not a shadow of evidence to shew that the sulci of a chimpanzee's, or orang's, brain

Gratiolet opens his preface with the aphorism: "Il est dangereux dans les sciences de conclure trop vite." I

fear he must have forgotten this sound maxim by the time he had reached the discussion of the differences

between men and apes, in the body of his work. No doubt, the excellent author of one of the most remarkable

contributions to the just understanding of the mammalian brain which has ever been made, would have been

the first to admit the insufficiency of his data had he lived to profit by the advance of inquiry. The misfortune

is that his conclusions have been employed by persons incompetent to appreciate their foundation, as

arguments in favour of obscurantism. (80. For example, M. l'Abbe Lecomte in his terrible pamphlet, 'Le

But it is important to remark that, whether Gratiolet was right or wrong in his hypothesis respecting the

relative order of appearance of the temporal and frontal sulci, the fact remains; that before either temporal or

frontal sulci, appear, the foetal brain of man presents characters which are found only in the lowest group of

the Primates (leaving out the Lemurs); and that this is exactly what we should expect to be the case, if man

has resulted from the gradual modification of the same form as that from which the other Primates have

Secondary sexual charactersSexual selectionManner of actionExcess of malesPolygamyThe

male alone generally modified through sexual selectionEagerness of the maleVariability of the

maleChoice exerted by the femaleSexual compared with natural selectionInheritance, at

corresponding periods of life, at corresponding seasons of the year, and as limited by sexRelations

between the several forms of inheritanceCauses why one sex and the young are not modified through

sexual selection Supplement on the proportional numbers of the two sexes throughout the animal

With animals which have their sexes separated, the males necessarily differ from the females in their organs

of reproduction; and these are the primary sexual characters. But the sexes often differ in what Hunter has

called secondary sexual characters, which are not directly connected with the act of reproduction; for

instance, the male possesses certain organs of sense or locomotion, of which the female is quite destitute, or

has them more highlydeveloped, in order that he may readily find or reach her; or again the male has special

organs of prehension for holding her securely. These latter organs, of infinitely diversified kinds, graduate

into those which are commonly ranked as primary, and in some cases can hardly be distinguished from them;

we see instances of this in the complex appendages at the apex of the abdomen in male insects. Unless indeed

we confine the term "primary" to the reproductive glands, it is scarcely possible to decide which ought to be

The female often differs from the male in having organs for the nourishment or protection of her young, such

as the mammary glands of mammals, and the abdominal sacks of the marsupials. In some few cases also the

male possesses similar organs, which are wanting in the female, such as the receptacles for the ova in certain

male fishes, and those temporarily developed in certain male frogs. The females of most bees are provided

with a special apparatus for collecting and carrying pollen, and their ovipositor is modified into a sting for the

defence of the larvae and the community. Many similar cases could be given, but they do not here concern us.

There are, however, other sexual differences quite unconnected with the primary reproductive organs, and it

is with these that we are more especially concernedsuch as the greater size, strength, and pugnacity of the

male, his weapons of offence or means of defence against rivals, his gaudy colouring and various ornaments,

Besides the primary and secondary sexual differences, such as the foregoing, the males and females of some

animals differ in structures related to different habits of life, and not at all, or only indirectly, to the

reproductive functions. Thus the females of certain flies (Culicidae and Tabanidae) are bloodsuckers, whilst

the males, living on flowers, have mouths destitute of mandibles. (1. Westwood, 'Modern Classification of

Insects,' vol. ii. 1840, p. 541. For the statement about Tanais, mentioned below, I am indebted to Fritz

Muller.) The males of certain moths and of some crustaceans (e.g. Tanais) have imperfect, closed mouths,

and cannot feed. The complemental males of certain Cirripedes live like epiphytic plants either on the female

or the hermaphrodite form, and are destitute of a mouth and of prehensile limbs. In these cases it is the male

which has been modified, and has lost certain important organs, which the females possess. In other cases it is

the female which has lost such parts; for instance, the female glowworm is destitute of wings, as also are

many female moths, some of which never leave their cocoons. Many female parasitic crustaceans have lost

their natatory legs. In some weevil beetles (Curculionidae) there is a great difference between the male and

female in the length of the rostrum or snout (2. Kirby and Spence, 'Introduction to Entomology,' vol. iii.

1826, p. 309.); but the meaning of this and of many analogous differences, is not at all understood.

Differences of structure between the two sexes in relation to different habits of life are generally confined to

the lower animals; but with some few birds the beak of the male differs from that of the female. In the Huia

of New Zealand the difference is wonderfully great, and we hear from Dr. Buller (3. 'Birds of New Zealand,'

1872, p. 66.) that the male uses his strong beak in chiselling the larvae of insects out of decayed wood, whilst

the female probes the softer parts with her far longer, much curved and pliant beak: and thus they mutually

aid each other. In most cases, differences of structure between the sexes are more or less directly connected

with the propagation of the species: thus a female, which has to nourish a multitude of ova, requires more

food than the male, and consequently requires special means for procuring it. A male animal, which lives for

a very short time, might lose its organs for procuring food through disuse, without detriment; but he would

retain his locomotive organs in a perfect state, so that he might reach the female. The female, on the other

hand, might safely lose her organs for flying, swimming, or walking, if she gradually acquired habits which

We are, however, here concerned only with sexual selection. This depends on the advantage which certain

individuals have over others of the same sex and species solely in respect of reproduction. When, as in the

cases above mentioned, the two sexes differ in structure in relation to different habits of life, they have no

doubt been modified through natural selection, and by inheritance limited to one and the same sex. So again

the primary sexual organs, and those for nourishing or protecting the young, come under the same influence;

for those individuals which generated or nourished their offspring best, would leave, ceteris paribus, the

greatest number to inherit their superiority; whilst those which generated or nourished their offspring badly,

would leave but few to inherit their weaker powers. As the male has to find the female, he requires organs of

sense and locomotion, but if these organs are necessary for the other purposes of life, as is generally the case,

they will have been developed through natural selection. When the male has found the female, he sometimes

absolutely requires prehensile organs to hold her; thus Dr. Wallace informs me that the males of certain

moths cannot unite with the females if their tarsi or feet are broken. The males of many oceanic crustaceans,

when adult, have their legs and antennae modified in an extraordinary manner for the prehension of the

female; hence we may suspect that it is because these animals are washed about by the waves of the open sea,

that they require these organs in order to propagate their kind, and if so, their development has been the result

of ordinary or natural selection. Some animals extremely low in the scale have been modified for this same

purpose; thus the males of certain parasitic worms, when fully grown, have the lower surface of the terminal

part of their bodies roughened like a rasp, and with this they coil round and permanently hold the females. (4.

M. Perrier advances this case ('Revue Scientifique,' Feb. 1, 1873, p. 865) as one fatal to the belief in sexual

election, inasmuch as he supposes that I attribute all the differences between the sexes to sexual selection.

This distinguished naturalist, therefore, like so many other Frenchmen, has not taken the trouble to

understand even the first principles of sexual selection. An English naturalist insists that the claspers of

certain male animals could not have been developed through the choice of the female! Had I not met with this

remark, I should not have thought it possible for any one to have read this chapter and to have imagined that I

maintain that the choice of the female had anything to do with the development of the prehensile organs in

When the two sexes follow exactly the same habits of life, and the male has the sensory or locomotive organs

more highly developed than those of the female, it may be that the perfection of these is indispensable to the

male for finding the female; but in the vast majority of cases, they serve only to give one male an advantage

over another, for with sufficient time, the less wellendowed males would succeed in pairing with the

females; and judging from the structure of the female, they would be in all other respects equally well

adapted for their ordinary habits of life. Since in such cases the males have acquired their present structure,

not from being better fitted to survive in the struggle for existence, but from having gained an advantage over

other males, and from having transmitted this advantage to their male offspring alone, sexual selection must

here have come into action. It was the importance of this distinction which led me to designate this form of

selection as Sexual Selection. So again, if the chief service rendered to the male by his prehensile organs is to

prevent the escape of the female before the arrival of other males, or when assaulted by them, these organs

will have been perfected through sexual selection, that is by the advantage acquired by certain individuals

over their rivals. But in most cases of this kind it is impossible to distinguish between the effects of natural

and sexual selection. Whole chapters could be filled with details on the differences between the sexes in their

sensory, locomotive, and prehensile organs. As, however, these structures are not more interesting than others

adapted for the ordinary purposes of life I shall pass them over almost entirely, giving only a few instances

There are many other structures and instincts which must have been developed through sexual

selectionsuch as the weapons of offence and the means of defence of the males for fighting with and

driving away their rivalstheir courage and pugnacitytheir various ornamentstheir contrivances for

producing vocal or instrumental musicand their glands for emitting odours, most of these latter structures

serving only to allure or excite the female. It is clear that these characters are the result of sexual and not of

ordinary selection, since unarmed, unornamented, or unattractive males would succeed equally well in the

battle for life and in leaving a numerous progeny, but for the presence of better endowed males. We may infer

that this would be the case, because the females, which are unarmed and unornamented, are able to survive

and procreate their kind. Secondary sexual characters of the kind just referred to, will be fully discussed in

the following chapters, as being in many respects interesting, but especially as depending on the will, choice,

and rivalry of the individuals of either sex. When we behold two males fighting for the possession of the

female, or several male birds displaying their gorgeous plumage, and performing strange antics before an

assembled body of females, we cannot doubt that, though led by instinct, they know what they are about, and

Just as man can improve the breeds of his gamecocks by the selection of those birds which are victorious in

the cockpit, so it appears that the strongest and most vigorous males, or those provided with the best

weapons, have prevailed under nature, and have led to the improvement of the natural breed or species. A

slight degree of variability leading to some advantage, however slight, in reiterated deadly contests would

suffice for the work of sexual selection; and it is certain that secondary sexual characters are eminently

variable. Just as man can give beauty, according to his standard of taste, to his male poultry, or more strictly

can modify the beauty originally acquired by the parent species, can give to the Sebright bantam a new and

elegant plumage, an erect and peculiar carriage so it appears that female birds in a state of nature, have by

a long selection of the more attractive males, added to their beauty or other attractive qualities. No doubt this

implies powers of discrimination and taste on the part of the female which will at first appear extremely

improbable; but by the facts to be adduced hereafter, I hope to be able to shew that the females actually have

these powers. When, however, it is said that the lower animals have a sense of beauty, it must not be

supposed that such sense is comparable with that of a cultivated man, with his multiform and complex

associated ideas. A more just comparison would be between the taste for the beautiful in animals, and that in

the lowest savages, who admire and deck themselves with any brilliant, glittering, or curious object.

From our ignorance on several points, the precise manner in which sexual selection acts is somewhat

uncertain. Nevertheless if those naturalists who already believe in the mutability of species, will read the

following chapters, they will, I think, agree with me, that sexual selection has played an important part in the

history of the organic world. It is certain that amongst almost all animals there is a struggle between the

males for the possession of the female. This fact is so notorious that it would be superfluous to give instances.

Hence the females have the opportunity of selecting one out of several males, on the supposition that their

mental capacity suffices for the exertion of a choice. In many cases special circumstances tend to make the

struggle between the males particularly severe. Thus the males of our migratory birds generally arrive at their

places of breeding before the females, so that many males are ready to contend for each female. I am

informed by Mr. Jenner Weir, that the birdcatchers assert that this is invariably the case with the nightingale

and blackcap, and with respect to the latter he can himself confirm the statement.

Mr. Swaysland of Brighton has been in the habit, during the last forty years, of catching our migratory birds

on their first arrival, and he has never known the females of any species to arrive before their males. During

one spring he shot thirtynine males of Ray's wagtail (Budytes Raii) before he saw a single female. Mr.

Gould has ascertained by the dissection of those snipes which arrive the first in this country, that the males

come before the females. And the like holds good with most of the migratory birds of the United States. (5.

J.A. Allen, on the 'Mammals and Winter Birds of Florida,' Bulletin of Comparative Zoology, Harvard

College, p. 268.) The majority of the male salmon in our rivers, on coming up from the sea, are ready to

breed before the females. So it appears to be with frogs and toads. Throughout the great class of insects the

males almost always are the first to emerge from the pupal state, so that they generally abound for a time

before any females can be seen. (6. Even with those plants in which the sexes are separate, the male flowers

are generally mature before the female. As first shewn by C.K. Sprengel, many hermaphrodite plants are

dichogamous; that is, their male and female organs are not ready at the same time, so that they cannot be

selffertilised. Now in such flowers, the pollen is in general matured before the stigma, though there are

exceptional cases in which the female organs are beforehand.) The cause of this difference between the males

and females in their periods of arrival and maturity is sufficiently obvious. Those males which annually first

migrated into any country, or which in the spring were first ready to breed, or were the most eager, would

leave the largest number of offspring; and these would tend to inherit similar instincts and constitutions. It

must be borne in mind that it would have been impossible to change very materially the time of sexual

maturity in the females, without at the same time interfering with the period of the production of the

younga period which must be determined by the seasons of the year. On the whole there can be no doubt

that with almost all animals, in which the sexes are separate, there is a constantly recurrent struggle between

Our difficulty in regard to sexual selection lies in understanding how it is that the males which conquer other

males, or those which prove the most attractive to the females, leave a greater number of offspring to inherit

their superiority than their beaten and less attractive rivals. Unless this result does follow, the characters

which give to certain males an advantage over others, could not be perfected and augmented through sexual

selection. When the sexes exist in exactly equal numbers, the worst endowed males will (except where

polygamy prevails), ultimately find females, and leave as many offspring, as well fitted for their general

habits of life, as the bestendowed males. From various facts and considerations, I formerly inferred that with

most animals, in which secondary sexual characters are well developed, the males considerably exceeded the

females in number; but this is not by any means always true. If the males were to the females as two to one,

or as three to two, or even in a somewhat lower ratio, the whole affair would be simple; for the betterarmed

or more attractive males would leave the largest number of offspring. But after investigating, as far as

possible, the numerical proportion of the sexes, I do not believe that any great inequality in number

commonly exists. In most cases sexual selection appears to have been effective in the following manner.

Let us take any species, a bird for instance, and divide the females inhabiting a district into two equal bodies,

the one consisting of the more vigorous and betternourished individuals, and the other of the less vigorous

and healthy. The former, there can be little doubt, would be ready to breed in the spring before the others; and

this is the opinion of Mr. Jenner Weir, who has carefully attended to the habits of birds during many years.

There can also be no doubt that the most vigorous, best nourished and earliest breeders would on an average

succeed in rearing the largest number of fine offspring. (7. Here is excellent evidence on the character of the

offspring from an experienced ornithologist. Mr. J.A. Allen, in speaking ('Mammals and Winter Birds of E.

Florida,' p. 229) of the later broods, after the accidental destruction of the first, says, that these "are found to

be smaller and palercoloured than those hatched earlier in the season. In cases where several broods are

reared each year, as a general rule the birds of the earlier broods seem in all respects the most perfect and

vigorous.") The males, as we have seen, are generally ready to breed before the females; the strongest, and

with some species the best armed of the males, drive away the weaker; and the former would then unite with

the more vigorous and betternourished females, because they are the first to breed. (8. Hermann Muller has

come to this same conclusion with respect to those female bees which are the first to emerge from the pupa

each year. See his remarkable essay, 'Anwendung der Darwin'schen Lehre auf Bienen,' 'Verh. d. V. Jahrg.'

xxix. p. 45.) Such vigorous pairs would surely rear a larger number of offspring than the retarded females,

which would be compelled to unite with the conquered and less powerful males, supposing the sexes to be

numerically equal; and this is all that is wanted to add, in the course of successive generations, to the size,

But in very many cases the males which conquer their rivals, do not obtain possession of the females,

independently of the choice of the latter. The courtship of animals is by no means so simple and short an

affair as might be thought. The females are most excited by, or prefer pairing with, the more ornamented

males, or those which are the best songsters, or play the best antics; but it is obviously probable that they

would at the same time prefer the more vigorous and lively males, and this has in some cases been confirmed

by actual observation. (9. With respect to poultry, I have received information, hereafter to be given, to this

effect. Even birds, such as pigeons, which pair for life, the female, as I hear from Mr. Jenner Weir, will desert

her mate if he is injured or grows weak.) Thus the more vigorous females, which are the first to breed, will

have the choice of many males; and though they may not always select the strongest or best armed, they will

select those which are vigorous and well armed, and in other respects the most attractive. Both sexes,

therefore, of such early pairs would as above explained, have an advantage over others in rearing offspring;

and this apparently has sufficed during a long course of generations to add not only to the strength and

fighting powers of the males, but likewise to their various ornaments or other attractions.

In the converse and much rarer case of the males selecting particular females, it is plain that those which were

the most vigorous and had conquered others, would have the freest choice; and it is almost certain that they

would select vigorous as well as attractive females. Such pairs would have an advantage in rearing offspring,

more especially if the male had the power to defend the female during the pairingseason as occurs with

some of the higher animals, or aided her in providing for the young. The same principles would apply if each

sex preferred and selected certain individuals of the opposite sex; supposing that they selected not only the

I have remarked that sexual selection would be a simple affair if the males were considerably more numerous

than the females. Hence I was led to investigate, as far as I could, the proportions between the two sexes of as

many animals as possible; but the materials are scanty. I will here give only a brief abstract of the results,

retaining the details for a supplementary discussion, so as not to interfere with the course of my argument.

Domesticated animals alone afford the means of ascertaining the proportional numbers at birth; but no

records have been specially kept for this purpose. By indirect means, however, I have collected a

considerable body of statistics, from which it appears that with most of our domestic animals the sexes are

nearly equal at birth. Thus 25,560 births of race horses have been recorded during twentyone years, and

the male births were to the female births as 99.7 to 100. In greyhounds the inequality is greater than with any

other animal, for out of 6878 births during twelve years, the male births were to the female as 110.1 to 100. It

is, however, in some degree doubtful whether it is safe to infer that the proportion would be the same under

natural conditions as under domestication; for slight and unknown differences in the conditions affect the

proportion of the sexes. Thus with mankind, the male births in England are as 104.5, in Russia as 108.9, and

with the Jews of Livonia as 120, to 100 female births. But I shall recur to this curious point of the excess of

male births in the supplement to this chapter. At the Cape of Good Hope, however, male children of

European extraction have been born during several years in the proportion of between 90 and 99 to 100

For our present purpose we are concerned with the proportions of the sexes, not only at birth, but also at

maturity, and this adds another element of doubt; for it is a wellascertained fact that with man the number of

males dying before or during birth, and during the first two years of infancy, is considerably larger than that

of females. So it almost certainly is with male lambs, and probably with some other animals. The males of

some species kill one another by fighting; or they drive one another about until they become greatly

emaciated. They must also be often exposed to various dangers, whilst wandering about in eager search for

the females. In many kinds of fish the males are much smaller than the females, and they are believed often to

be devoured by the latter, or by other fishes. The females of some birds appear to die earlier than the males;

they are also liable to be destroyed on their nests, or whilst in charge of their young. With insects the female

larvae are often larger than those of the males, and would consequently be more likely to be devoured. In

some cases the mature females are less active and less rapid in their movements than the males, and could not

escape so well from danger. Hence, with animals in a state of nature, we must rely on mere estimation, in

order to judge of the proportions of the sexes at maturity; and this is but little trustworthy, except when the

inequality is strongly marked. Nevertheless, as far as a judgment can be formed, we may conclude from the

facts given in the supplement, that the males of some few mammals, of many birds, of some fish and insects,

The proportion between the sexes fluctuates slightly during successive years: thus with racehorses, for every

100 mares born the stallions varied from 107.1 in one year to 92.6 in another year, and with greyhounds from

116.3 to 95.3. But had larger numbers been tabulated throughout an area more extensive than England, these

fluctuations would probably have disappeared; and such as they are, would hardly suffice to lead to effective

sexual selection in a state of nature. Nevertheless, in the cases of some few wild animals, as shewn in the

supplement, the proportions seem to fluctuate either during different seasons or in different localities in a

sufficient degree to lead to such selection. For it should be observed that any advantage, gained during certain

years or in certain localities by those males which were able to conquer their rivals, or were the most

attractive to the females, would probably be transmitted to the offspring, and would not subsequently be

eliminated. During the succeeding seasons, when, from the equality of the sexes, every male was able to

procure a female, the stronger or more attractive males previously produced would still have at least as good

The practice of polygamy leads to the same results as would follow from an actual inequality in the number

of the sexes; for if each male secures two or more females, many males cannot pair; and the latter assuredly

will be the weaker or less attractive individuals. Many mammals and some few birds are polygamous, but

with animals belonging to the lower classes I have found no evidence of this habit. The intellectual powers of

such animals are, perhaps, not sufficient to lead them to collect and guard a harem of females. That some

relation exists between polygamy and the development of secondary sexual characters, appears nearly

certain; and this supports the view that a numerical preponderance of males would be eminently favourable to

the action of sexual selection. Nevertheless many animals, which are strictly monogamous, especially birds,

display stronglymarked secondary sexual characters; whilst some few animals, which are polygamous, do

We will first briefly run through the mammals, and then turn to birds. The gorilla seems to be polygamous,

and the male differs considerably from the female; so it is with some baboons, which live in herds containing

twice as many adult females as males. In South America the Mycetes caraya presents wellmarked sexual

differences, in colour, beard, and vocal organs; and the male generally lives with two or three wives: the male

of the Cebus capucinus differs somewhat from the female, and appears to be polygamous. (10. On the

Gorilla, Savage and Wyman, 'Boston Journal of Natural History,' vol. v. 184547, p. 423. On Cynocephalus,

Brehm, 'Thierleben,' B. i. 1864, s. 77. On Mycetes, Rengger, 'Naturgeschichte der Saugethiere von Paraguay,'

1830, ss. 14, 20. On Cebus, Brehm, ibid. s. 108.) Little is known on this head with respect to most other

monkeys, but some species are strictly monogamous. The ruminants are eminently polygamous, and they

present sexual differences more frequently than almost any other group of mammals; this holds good,

especially in their weapons, but also in other characters. Most deer, cattle, and sheep are polygamous; as are

most antelopes, though some are monogamous. Sir Andrew Smith, in speaking of the antelopes of South

Africa, says that in herds of about a dozen there was rarely more than one mature male. The Asiatic Antilope

saiga appears to be the most inordinate polygamist in the world; for Pallas (11. Pallas, 'Spicilegia Zoolog.,

Fasc.' xii. 1777, p. 29. Sir Andrew Smith, 'Illustrations of the Zoology of S. Africa,' 1849, pl. 29, on the

Kobus. Owen, in his 'Anatomy of Vertebrates' (vol. iii. 1868, p. 633) gives a table shewing incidentally which

species of antelopes are gregarious.) states that the male drives away all rivals, and collects a herd of about a

hundred females and kids together; the female is hornless and has softer hair, but does not otherwise differ

much from the male. The wild horse of the Falkland Islands and of the Western States of N. America is

polygamous, but, except in his greater size and in the proportions of his body, differs but little from the mare.

The wild boar presents wellmarked sexual characters, in his great tusks and some other points. In Europe

and in India he leads a solitary life, except during the breedingseason; but as is believed by Sir W. Elliot,

who has had many opportunities in India of observing this animal, he consorts at this season with several

females. Whether this holds good in Europe is doubtful, but it is supported by some evidence. The adult male

Indian elephant, like the boar, passes much of his time in solitude; but as Dr. Campbell states, when with

others, "It is rare to find more than one male with a whole herd of females"; the larger males expelling or

killing the smaller and weaker ones. The male differs from the female in his immense tusks, greater size,

strength, and endurance; so great is the difference in these respects that the males when caught are valued at

onefifth more than the females. (12. Dr. Campbell, in 'Proc. Zoolog. Soc.' 1869, p. 138. See also an

interesting paper by Lieut. Johnstone, in 'Proceedings, Asiatic Society of Bengal,' May 1868.) The sexes of

other pachydermatous animals differ very little or not at all, and, as far as known, they are not polygamists.

Nor have I heard of any species in the Orders of Cheiroptera, Edentata, Insectivora and Rodents being

polygamous, excepting that amongst the Rodents, the common rat, according to some ratcatchers, lives with

several females. Nevertheless the two sexes of some sloths (Edentata) differ in the character and colour of

certain patches of hair on their shoulders. (13. Dr. Gray, in 'Annals and Magazine of Natural History,' 1871,

p. 302.) And many kinds of bats (Cheiroptera) present wellmarked sexual differences, chiefly in the males

possessing odoriferous glands and pouches, and by their being of a lighter colour. (14. See Dr. Dobson's

excellent paper in 'Proceedings of the Zoological Society,' 1873, p. 241.) In the great order of Rodents, as far

as I can learn, the sexes rarely differ, and when they do so, it is but slightly in the tint of the fur.

As I hear from Sir Andrew Smith, the lion in South Africa sometimes lives with a single female, but

generally with more, and, in one case, was found with as many as five females; so that he is polygamous. As

far as I can discover, he is the only polygamist amongst all the terrestrial Carnivora, and he alone presents

wellmarked sexual characters. If, however, we turn to the marine Carnivora, as we shall hereafter see, the

case is widely different; for many species of seals offer extraordinary sexual differences, and they are

eminently polygamous. Thus, according to Peron, the male seaelephant of the Southern Ocean always

possesses several females, and the sealion of Forster is said to be surrounded by from twenty to thirty

females. In the North, the male seabear of Steller is accompanied by even a greater number of females. It is

an interesting fact, as Dr. Gill remarks (15. 'The Eared Seals,' American Naturalist, vol. iv. Jan. 1871.), that in

the monogamous species, "or those living in small communities, there is little difference in size between the

males and females; in the social species, or rather those of which the males have harems, the males are vastly

Amongst birds, many species, the sexes of which differ greatly from each other, are certainly monogamous.

In Great Britain we see wellmarked sexual differences, for instance, in the wildduck which pairs with a

single female, the common blackbird, and the bullfinch which is said to pair for life. I am informed by Mr.

Wallace that the like is true of the Chatterers or Cotingidae of South America, and of many other birds. In

several groups I have not been able to discover whether the species are polygamous or monogamous. Lesson

says that birds of paradise, so remarkable for their sexual differences, are polygamous, but Mr. Wallace

doubts whether he had sufficient evidence. Mr. Salvin tells me he has been led to believe that hummingbirds

are polygamous. The male widowbird, remarkable for his caudal plumes, certainly seems to be a

polygamist. (16. 'The Ibis,' vol. iii. 1861, p. 133, on the Progne Widowbird. See also on the Vidua axillaris,

ibid. vol. ii. 1860, p. 211. On the polygamy of the Capercailzie and Great Bustard, see L. Lloyd, 'Game Birds

of Sweden,' 1867, pp. 19, and 182. Montagu and Selby speak of the Black Grouse as polygamous and of the

Red Grouse as monogamous.) I have been assured by Mr. Jenner Weir and by others, that it is somewhat

common for three starlings to frequent the same nest; but whether this is a case of polygamy or polyandry has

The Gallinaceae exhibit almost as strongly marked sexual differences as birds of paradise or hummingbirds,

and many of the species are, as is well known, polygamous; others being strictly monogamous. What a

contrast is presented between the sexes of the polygamous peacock or pheasant, and the monogamous

guineafowl or partridge! Many similar cases could be given, as in the grouse tribe, in which the males of the

polygamous capercailzie and blackcock differ greatly from the females; whilst the sexes of the

monogamous red grouse and ptarmigan differ very little. In the Cursores, except amongst the bustards, few

species offer stronglymarked sexual differences, and the great bustard (Otis tarda) is said to be polygamous.

With the Grallatores, extremely few species differ sexually, but the ruff (Machetes pugnax) affords a marked

exception, and this species is believed by Montagu to be a polygamist. Hence it appears that amongst birds

there often exists a close relation between polygamy and the development of stronglymarked sexual

differences. I asked Mr. Bartlett, of the Zoological Gardens, who has had very large experience with birds,

whether the male tragopan (one of the Gallinaceae) was polygamous, and I was struck by his answering, "I do

It deserves notice that the instinct of pairing with a single female is easily lost under domestication. The

wildduck is strictly monogamous, the domesticduck highly polygamous. The Rev. W.D. Fox informs me

that out of some halftamed wildducks, on a large pond in his neighbourhood, so many mallards were shot

by the gamekeeper that only one was left for every seven or eight females; yet unusually large broods were

reared. The guineafowl is strictly monogamous; but Mr. Fox finds that his birds succeed best when he keeps

one cock to two or three hens. Canarybirds pair in a state of nature, but the breeders in England successfully

put one male to four or five females. I have noticed these cases, as rendering it probable that wild

monogamous species might readily become either temporarily or permanently polygamous.

Too little is known of the habits of reptiles and fishes to enable us to speak of their marriage arrangements.

The stickleback (Gasterosteus), however, is said to be a polygamist (17. Noel Humphreys, 'River Gardens,'

1857.); and the male during the breedingseason differs conspicuously from the female.

To sum up on the means through which, as far as we can judge, sexual selection has led to the development

of secondary sexual characters. It has been shewn that the largest number of vigorous offspring will be reared

from the pairing of the strongest and bestarmed males, victorious in contests over other males, with the most

vigorous and bestnourished females, which are the first to breed in the spring. If such females select the

more attractive, and at the same time vigorous males, they will rear a larger number of offspring than the

retarded females, which must pair with the less vigorous and less attractive males. So it will be if the more

vigorous males select the more attractive and at the same time healthy and vigorous females; and this will

especially hold good if the male defends the female, and aids in providing food for the young. The advantage

thus gained by the more vigorous pairs in rearing a larger number of offspring has apparently sufficed to

render sexual selection efficient. But a large numerical preponderance of males over females will be still

more efficient; whether the preponderance is only occasional and local, or permanent; whether it occurs at

birth, or afterwards from the greater destruction of the females; or whether it indirectly follows from the

Throughout the animal kingdom, when the sexes differ in external appearance, it is, with rare exceptions, the

male which has been the more modified; for, generally, the female retains a closer resemblance to the young

of her own species, and to other adult members of the same group. The cause of this seems to lie in the males

of almost all animals having stronger passions than the females. Hence it is the males that fight together and

sedulously display their charms before the females; and the victors transmit their superiority to their male

offspring. Why both sexes do not thus acquire the characters of their fathers, will be considered hereafter.

That the males of all mammals eagerly pursue the females is notorious to every one. So it is with birds; but

many cock birds do not so much pursue the hen, as display their plumage, perform strange antics, and pour

forth their song in her presence. The male in the few fish observed seems much more eager than the female;

and the same is true of alligators, and apparently of Batrachians. Throughout the enormous class of insects, as

Kirby remarks, "the law is that the male shall seek the female." (18. Kirby and Spence, 'Introduction to

Entomology,' vol. iii. 1826, p. 342.) Two good authorities, Mr. Blackwall and Mr. C. Spence Bate, tell me

that the males of spiders and crustaceans are more active and more erratic in their habits than the females.

When the organs of sense or locomotion are present in the one sex of insects and crustaceans and absent in

the other, or when, as is frequently the case, they are more highly developed in the one than in the other, it is,

as far as I can discover, almost invariably the male which retains such organs, or has them most developed;

and this shews that the male is the more active member in the courtship of the sexes. (19. One parasitic

Hymenopterous insect (Westwood, 'Modern Class. of Insects,' vol. ii. p. 160) forms an exception to the rule,

as the male has rudimentary wings, and never quits the cell in which it is born, whilst the female has

welldeveloped wings. Audouin believes that the females of this species are impregnated by the males which

are born in the same cells with them; but it is much more probable that the females visit other cells, so that

close interbreeding is thus avoided. We shall hereafter meet in various classes, with a few exceptional cases,

The female, on the other hand, with the rarest exceptions, is less eager than the male. As the illustrious

Hunter (20. 'Essays and Observations,' edited by Owen, vol. i. 1861, p. 194.) long ago observed, she generally

"requires to be courted;" she is coy, and may often be seen endeavouring for a long time to escape from the

male. Every observer of the habits of animals will be able to call to mind instances of this kind. It is shewn by

various facts, given hereafter, and by the results fairly attributable to sexual selection, that the female, though

comparatively passive, generally exerts some choice and accepts one male in preference to others. Or she

may accept, as appearances would sometimes lead us to believe, not the male which is the most attractive to

her, but the one which is the least distasteful. The exertion of some choice on the part of the female seems a

We are naturally led to enquire why the male, in so many and such distinct classes, has become more eager

than the female, so that he searches for her, and plays the more active part in courtship. It would be no

advantage and some loss of power if each sex searched for the other; but why should the male almost always

be the seeker? The ovules of plants after fertilisation have to be nourished for a time; hence the pollen is

necessarily brought to the female organsbeing placed on the stigma, by means of insects or the wind, or by

the spontaneous movements of the stamens; and in the Algae, etc., by the locomotive power of the

antherozooids. With lowlyorganised aquatic animals, permanently affixed to the same spot and having their

sexes separate, the male element is invariably brought to the female; and of this we can see the reason, for

even if the ova were detached before fertilisation, and did not require subsequent nourishment or protection,

there would yet be greater difficulty in transporting them than the male element, because, being larger than

the latter, they are produced in far smaller numbers. So that many of the lower animals are, in this respect,

analogous with plants. (21. Prof. Sachs ('Lehrbuch der Botanik,' 1870, S. 633) in speaking of the male and

female reproductive cells, remarks, "verhalt sich die eine bei der Vereinigung activ,...die andere erscheint bei

der Vereinigung passiv.") The males of affixed and aquatic animals having been led to emit their fertilising

element in this way, it is natural that any of their descendants, which rose in the scale and became

locomotive, should retain the same habit; and they would approach the female as closely as possible, in order

not to risk the loss of the fertilising element in a long passage of it through the water. With some few of the

lower animals, the females alone are fixed, and the males of these must be the seekers. But it is difficult to

understand why the males of species, of which the progenitors were primordially free, should invariably have

acquired the habit of approaching the females, instead of being approached by them. But in all cases, in order

that the males should seek efficiently, it would be necessary that they should be endowed with strong

passions; and the acquirement of such passions would naturally follow from the more eager leaving a larger

The great eagerness of the males has thus indirectly led to their much more frequently developing secondary

sexual characters than the females. But the development of such characters would be much aided, if the males

were more liable to vary than the femalesas I concluded they wereafter a long study of domesticated

animals. Von Nathusius, who has had very wide experience, is strongly of the same opinion. (22. 'Vortrage

uber Viehzucht,' 1872, p. 63.) Good evidence also in favour of this conclusion can be produced by a

comparison of the two sexes in mankind. During the Novara Expedition (23. 'Reise der Novara: Anthropolog.

Theil,' 1867, ss. 216269. The results were calculated by Dr. Weisbach from measurements made by Drs. K.

Scherzer and Schwarz. On the greater variability of the males of domesticated animals, see my 'Variation of

Animals and Plants under Domestication,' vol. ii. 1868, p. 75.) a vast number of measurements was made of

various parts of the body in different races, and the men were found in almost every case to present a greater

range of variation than the women; but I shall have to recur to this subject in a future chapter. Mr. J. Wood

(24. 'Proceedings of the Royal Society,' vol. xvi. July 1868, pp. 519 and 524.), who has carefully attended to

the variation of the muscles in man, puts in italics the conclusion that "the greatest number of abnormalities

in each subject is found in the males." He had previously remarked that "altogether in 102 subjects, the

varieties of redundancy were found to be half as many again as in females, contrasting widely with the

greater frequency of deficiency in females before described." Professor Macalister likewise remarks (25.

'Proc. Royal Irish Academy,' vol. x. 1868, p. 123.) that variations in the muscles "are probably more common

in males than females." Certain muscles which are not normally present in mankind are also more frequently

developed in the male than in the female sex, although exceptions to this rule are said to occur. Dr. Burt

Wilder (26. 'Massachusetts Medical Society,' vol. ii. No. 3, 1868, p. 9.) has tabulated the cases of 152

individuals with supernumerary digits, of which 86 were males, and 39, or less than half, females, the

remaining 27 being of unknown sex. It should not, however, be overlooked that women would more

frequently endeavour to conceal a deformity of this kind than men. Again, Dr. L. Meyer asserts that the ears

of man are more variable in form than those of a woman. (27. 'Archiv fur Path. Anat. und Phys.' 1871, p.

488.) Lastly the temperature is more variable in man than in woman. (28. The conclusions recently arrived at

by Dr. J. Stockton Hough, on the temperature of man, are given in the 'Pop. Sci. Review,' Jan. 1st, 1874, p.

The cause of the greater general variability in the male sex, than in the female is unknown, except in so far as

secondary sexual characters are extraordinarily variable, and are usually confined to the males; and, as we

shall presently see, this fact is, to a certain extent, intelligible. Through the action of sexual and natural

selection male animals have been rendered in very many instances widely different from their females; but

independently of selection the two sexes, from differing constitutionally, tend to vary in a somewhat different

manner. The female has to expend much organic matter in the formation of her ova, whereas the male

expends much force in fierce contests with his rivals, in wandering about in search of the female, in exerting

his voice, pouring out odoriferous secretions, etc.: and this expenditure is generally concentrated within a

short period. The great vigour of the male during the season of love seems often to intensify his colours,

independently of any marked difference from the female. (29. Prof. Mantegazza is inclined to believe

('Lettera a Carlo Darwin,' 'Archivio per l'Anthropologia,' 1871, p. 306) that the bright colours, common in so

many male animals, are due to the presence and retention by them of the spermatic fluid; but this can hardly

be the case; for many male birds, for instance young pheasants, become brightly coloured in the autumn of

their first year.) In mankind, and even as low down in the organic scale as in the Lepidoptera, the temperature

of the body is higher in the male than in the female, accompanied in the case of man by a slower pulse. (30.

For mankind, see Dr. J. Stockton Hough, whose conclusions are given in the 'Popular Science Review,' 1874,

p. 97. See Girard's observations on the Lepidoptera, as given in the 'Zoological Record,' 1869, p. 347.) On the

whole the expenditure of matter and force by the two sexes is probably nearly equal, though effected in very

From the causes just specified the two sexes can hardly fail to differ somewhat in constitution, at least during

the breedingseason; and, although they may be subjected to exactly the same conditions, they will tend to

vary in a different manner. If such variations are of no service to either sex, they will not be accumulated and

increased by sexual or natural selection. Nevertheless, they may become permanent if the exciting cause acts

permanently; and in accordance with a frequent form of inheritance they may be transmitted to that sex alone

in which they first appeared. In this case the two sexes will come to present permanent, yet unimportant,

differences of character. For instance, Mr. Allen shews that with a large number of birds inhabiting the

northern and southern United States, the specimens from the south are darkercoloured than those from the

north; and this seems to be the direct result of the difference in temperature, light, etc., between the two

regions. Now, in some few cases, the two sexes of the same species appear to have been differently affected;

in the Agelaeus phoeniceus the males have had their colours greatly intensified in the south; whereas with

Cardinalis virginianus it is the females which have been thus affected; with Quiscalus major the females have

been rendered extremely variable in tint, whilst the males remain nearly uniform. (31. 'Mammals and Birds of

A few exceptional cases occur in various classes of animals, in which the females instead of the males have

acquired well pronounced secondary sexual characters, such as brighter colours, greater size, strength, or

pugnacity. With birds there has sometimes been a complete transposition of the ordinary characters proper to

each sex; the females having become the more eager in courtship, the males remaining comparatively

passive, but apparently selecting the more attractive females, as we may infer from the results. Certain hen

birds have thus been rendered more highly coloured or otherwise ornamented, as well as more powerful and

pugnacious than the cocks; these characters being transmitted to the female offspring alone.

It may be suggested that in some cases a double process of selection has been carried on; that the males have

selected the more attractive females, and the latter the more attractive males. This process, however, though it

might lead to the modification of both sexes, would not make the one sex different from the other, unless

indeed their tastes for the beautiful differed; but this is a supposition too improbable to be worth considering

in the case of any animal, excepting man. There are, however, many animals in which the sexes resemble

each other, both being furnished with the same ornaments, which analogy would lead us to attribute to the

agency of sexual selection. In such cases it may be suggested with more plausibility, that there has been a

double or mutual process of sexual selection; the more vigorous and precocious females selecting the more

attractive and vigorous males, the latter rejecting all except the more attractive females. But from what we

know of the habits of animals, this view is hardly probable, for the male is generally eager to pair with any

female. It is more probable that the ornaments common to both sexes were acquired by one sex, generally the

male, and then transmitted to the offspring of both sexes. If, indeed, during a lengthened period the males of

any species were greatly to exceed the females in number, and then during another lengthened period, but

under different conditions, the reverse were to occur, a double, but not simultaneous, process of sexual

selection might easily be carried on, by which the two sexes might be rendered widely different.

We shall hereafter see that many animals exist, of which neither sex is brilliantly coloured or provided with

special ornaments, and yet the members of both sexes or of one alone have probably acquired simple colours,

such as white or black, through sexual selection. The absence of bright tints or other ornaments may be the

result of variations of the right kind never having occurred, or of the animals themselves having preferred

plain black or white. Obscure tints have often been developed through natural selection for the sake of

protection, and the acquirement through sexual selection of conspicuous colours, appears to have been

sometimes checked from the danger thus incurred. But in other cases the males during long ages may have

struggled together for the possession of the females, and yet no effect will have been produced, unless a

larger number of offspring were left by the more successful males to inherit their superiority, than by the less

successful: and this, as previously shewn, depends on many complex contingencies.

Sexual selection acts in a less rigorous manner than natural selection. The latter produces its effects by the

life or death at all ages of the more or less successful individuals. Death, indeed, not rarely ensues from the

conflicts of rival males. But generally the less successful male merely fails to obtain a female, or obtains a

retarded and less vigorous female later in the season, or, if polygamous, obtains fewer females; so that they

leave fewer, less vigorous, or no offspring. In regard to structures acquired through ordinary or natural

selection, there is in most cases, as long as the conditions of life remain the same, a limit to the amount of

advantageous modification in relation to certain special purposes; but in regard to structures adapted to make

one male victorious over another, either in fighting or in charming the female, there is no definite limit to the

amount of advantageous modification; so that as long as the proper variations arise the work of sexual

selection will go on. This circumstance may partly account for the frequent and extraordinary amount of

variability presented by secondary sexual characters. Nevertheless, natural selection will determine that such

characters shall not be acquired by the victorious males, if they would be highly injurious, either by

expending too much of their vital powers, or by exposing them to any great danger. The development,

however, of certain structuresof the horns, for instance, in certain stagshas been carried to a wonderful

extreme; and in some cases to an extreme which, as far as the general conditions of life are concerned, must

be slightly injurious to the male. From this fact we learn that the advantages which favoured males derive

from conquering other males in battle or courtship, and thus leaving a numerous progeny, are in the long run

greater than those derived from rather more perfect adaptation to their conditions of life. We shall further see,

and it could never have been anticipated, that the power to charm the female has sometimes been more

In order to understand how sexual selection has acted on many animals of many classes, and in the course of

ages has produced a conspicuous result, it is necessary to bear in mind the laws of inheritance, as far as they

are known. Two distinct elements are included under the term "inheritance" the transmission, and the

development of characters; but as these generally go together, the distinction is often overlooked. We see this

distinction in those characters which are transmitted through the early years of life, but are developed only at

maturity or during old age. We see the same distinction more clearly with secondary sexual characters, for

these are transmitted through both sexes, though developed in one alone. That they are present in both sexes,

is manifest when two species, having strongly marked sexual characters, are crossed, for each transmits the

characters proper to its own male and female sex to the hybrid offspring of either sex. The same fact is

likewise manifest, when characters proper to the male are occasionally developed in the female when she

grows old or becomes diseased, as, for instance, when the common hen assumes the flowing tail feathers,

hackles, comb, spurs, voice, and even pugnacity of the cock. Conversely, the same thing is evident, more or

less plainly, with castrated males. Again, independently of old age or disease, characters are occasionally

transferred from the male to the female, as when, in certain breeds of the fowl, spurs regularly appear in the

young and healthy females. But in truth they are simply developed in the female; for in every breed each

detail in the structure of the spur is transmitted through the female to her male offspring. Many cases will

hereafter be given, where the female exhibits, more or less perfectly, characters proper to the male, in whom

they must have been first developed, and then transferred to the female. The converse case of the first

development of characters in the female and of transference to the male, is less frequent; it will therefore be

well to give one striking instance. With bees the pollen collecting apparatus is used by the female alone for

gathering pollen for the larvae, yet in most of the species it is partially developed in the males to whom it is

quite useless, and it is perfectly developed in the males of Bombus or the humblebee. (32. H. Muller,

'Anwendung der Darwin'schen Lehre,' etc., Verh. d. n. V. Jahrg., xxix. p. 42.) As not a single other

Hymenopterous insect, not even the wasp, which is closely allied to the bee, is provided with a

pollencollecting apparatus, we have no grounds for supposing that male bees primordially collected pollen

as well as the females; although we have some reason to suspect that male mammals primordially suckled

their young as well as the females. Lastly, in all cases of reversion, characters are transmitted through two,

three, or many more generations, and are then developed under certain unknown favourable conditions. This

important distinction between transmission and development will be best kept in mind by the aid of the

hypothesis of pangenesis. According to this hypothesis, every unit or cell of the body throws off gemmules or

undeveloped atoms, which are transmitted to the offspring of both sexes, and are multiplied by selfdivision.

They may remain undeveloped during the early years of life or during successive generations; and their

development into units or cells, like those from which they were derived, depends on their affinity for, and

union with other units or cells previously developed in the due order of growth.

This tendency is well established. A new character, appearing in a young animal, whether it lasts throughout

life or is only transient, will, in general, reappear in the offspring at the same age and last for the same time.

If, on the other hand, a new character appears at maturity, or even during old age, it tends to reappear in the

offspring at the same advanced age. When deviations from this rule occur, the transmitted characters much

oftener appear before, than after the corresponding age. As I have dwelt on this subject sufficiently in another

work (33. The 'Variation of Animals and Plants under Domestication,' vol. ii. 1868, p. 75. In the last chapter

but one, the provisional hypothesis of pangenesis, above alluded to, is fully explained.), I will here merely

give two or three instances, for the sake of recalling the subject to the reader's mind. In several breeds of the

Fowl, the downcovered chickens, the young birds in their first true plumage, and the adults differ greatly

from one another, as well as from their common parentform, the Gallus bankiva; and these characters are

faithfully transmitted by each breed to their offspring at the corresponding periods of life. For instance, the

chickens of spangled Hamburgs, whilst covered with down, have a few dark spots on the head and rump, but

are not striped longitudinally, as in many other breeds; in their first true plumage, "they are beautifully

pencilled," that is each feather is transversely marked by numerous dark bars; but in their second plumage the

feathers all become spangled or tipped with a dark round spot. (34. These facts are given on the high

authority of a great breeder, Mr. Teebay; see Tegetmeier's 'Poultry Book,' 1868, p. 158. On the characters of

chickens of different breeds, and on the breeds of the pigeon, alluded to in the following paragraph, see

'Variation of Animals,' etc., vol. i. pp. 160, 249; vol. ii. p. 77.) Hence in this breed variations have occurred

at, and been transmitted to, three distinct periods of life. The Pigeon offers a more remarkable case, because

the aboriginal parent species does not undergo any change of plumage with advancing age, excepting that at

maturity the breast becomes more iridescent; yet there are breeds which do not acquire their characteristic

colours until they have moulted two, three, or four times; and these modifications of plumage are regularly

With animals in a state of nature, innumerable instances occur of characters appearing periodically at

different seasons. We see this in the horns of the stag, and in the fur of Artic animals which becomes thick

and white during the winter. Many birds acquire bright colours and other decorations during the

breedingseason alone. Pallas states (35. 'Novae species Quadrupedum e Glirium ordine,' 1778, p. 7. On the

transmission of colour by the horse, see 'Variation of Animals and Plants under Domestication,' vol. i. p. 51.

Also vol. ii. p. 71, for a general discussion on 'Inheritance as limited by Sex.'), that in Siberia domestic cattle

and horses become lightercoloured during the winter; and I have myself observed, and heard of similar

strongly marked changes of colour, that is, from brownish creamcolour or reddishbrown to a perfect white,

in several ponies in England. Although I do not know that this tendency to change the colour of the coat

during different seasons is transmitted, yet it probably is so, as all shades of colour are strongly inherited by

the horse. Nor is this form of inheritance, as limited by the seasons, more remarkable than its limitation by

The equal transmission of characters to both sexes is the commonest form of inheritance, at least with those

animals which do not present strongly marked sexual differences, and indeed with many of these. But

characters are somewhat commonly transferred exclusively to that sex, in which they first appear. Ample

evidence on this head has been advanced in my work on 'Variation under Domestication,' but a few instances

may here be given. There are breeds of the sheep and goat, in which the horns of the male differ greatly in

shape from those of the female; and these differences, acquired under domestication, are regularly transmitted

to the same sex. As a rule, it is the females alone in cats which are tortoiseshell, the corresponding colour in

the males being rustyred. With most breeds of the fowl, the characters proper to each sex are transmitted to

the same sex alone. So general is this form of transmission that it is an anomaly when variations in certain

breeds are transmitted equally to both sexes. There are also certain subbreeds of the fowl in which the males

can hardly be distinguished from one another, whilst the females differ considerably in colour. The sexes of

the pigeon in the parentspecies do not differ in any external character; nevertheless, in certain domesticated

breeds the male is coloured differently from the female. (36. Dr. Chapuis, 'Le Pigeon Voyageur Belge,' 1865,

p. 87. Boitard et Corbie, 'Les Pigeons de Voliere,' etc., 1824, p. 173. See, also, on similar differences in

certain breeds at Modena, 'Le variazioni dei Colombi domestici,' del Paolo Bonizzi, 1873.) The wattle in the

English Carrier pigeon, and the crop in the Pouter, are more highly developed in the male than in the female;

and although these characters have been gained through longcontinued selection by man, the slight

differences between the sexes are wholly due to the form of inheritance which has prevailed; for they have

Most of our domestic races have been formed by the accumulation of many slight variations; and as some of

the successive steps have been transmitted to one sex alone, and some to both sexes, we find in the different

breeds of the same species all gradations between great sexual dissimilarity and complete similarity.

Instances have already been given with the breeds of the fowl and pigeon, and under nature analogous cases

are common. With animals under domestication, but whether in nature I will not venture to say, one sex may

lose characters proper to it, and may thus come somewhat to resemble the opposite sex; for instance, the

males of some breeds of the fowl have lost their masculine tailplumes and hackles. On the other hand, the

differences between the sexes may be increased under domestication, as with merino sheep, in which the

ewes have lost their horns. Again, characters proper to one sex may suddenly appear in the other sex; as in

those subbreeds of the fowl in which the hens acquire spurs whilst young; or, as in certain Polish

subbreeds, in which the females, as there is reason to believe, originally acquired a crest, and subsequently

transferred it to the males. All these cases are intelligible on the hypothesis of pangenesis; for they depend on

the gemmules of certain parts, although present in both sexes, becoming, through the influence of

There is one difficult question which it will be convenient to defer to a future chapter; namely, whether a

character at first developed in both sexes, could through selection be limited in its development to one sex

alone. If, for instance, a breeder observed that some of his pigeons (of which the characters are usually

transferred in an equal degree to both sexes) varied into pale blue, could he by longcontinued selection

make a breed, in which the males alone should be of this tint, whilst the females remained unchanged? I will

here only say, that this, though perhaps not impossible, would be extremely difficult; for the natural result of

breeding from the paleblue males would be to change the whole stock of both sexes to this tint. If, however,

variations of the desired tint appeared, which were from the first limited in their development to the male sex,

there would not be the least difficulty in making a breed with the two sexes of a different colour, as indeed

has been effected with a Belgian breed, in which the males alone are streaked with black. In a similar manner,

if any variation appeared in a female pigeon, which was from the first sexually limited in its development to

the females, it would be easy to make a breed with the females alone thus characterised; but if the variation

was not thus originally limited, the process would be extremely difficult, perhaps impossible. (37. Since the

publication of the first edition of this work, it has been highly satisfactory to me to find the following remarks

(the 'Field,' Sept. 1872) from so experienced a breeder as Mr. Tegetmeier. After describing some curious

cases in pigeons, of the transmission of colour by one sex alone, and the formation of a sub breed with this

character, he says: "It is a singular circumstance that Mr. Darwin should have suggested the possibility of

modifying the sexual colours of birds by a course of artificial selection. When he did so, he was in ignorance

of these facts that I have related; but it is remarkable how very closely he suggested the right method of

Why certain characters should be inherited by both sexes, and other characters by one sex alone, namely by

that sex in which the character first appeared, is in most cases quite unknown. We cannot even conjecture

why with certain subbreeds of the pigeon, black striae, though transmitted through the female, should be

developed in the male alone, whilst every other character is equally transferred to both sexes. Why, again,

with cats, the tortoiseshell colour should, with rare exceptions, be developed in the female alone. The very

same character, such as deficient or supernumerary digits, colourblindness, etc., may with mankind be

inherited by the males alone of one family, and in another family by the females alone, though in both cases

transmitted through the opposite as well as through the same sex. (38. References are given in my 'Variation

of Animals and Plants under Domestication,' vol. ii. p. 72.) Although we are thus ignorant, the two following

rules seem often to hold goodthat variations which first appear in either sex at a late period of life, tend to

be developed in the same sex alone; whilst variations which first appear early in life in either sex tend to be

developed in both sexes. I am, however, far from supposing that this is the sole determining cause. As I have

not elsewhere discussed this subject, and it has an important bearing on sexual selection, I must here enter

It is in itself probable that any character appearing at an early age would tend to be inherited equally by both

sexes, for the sexes do not differ much in constitution before the power of reproduction is gained. On the

other hand, after this power has been gained and the sexes have come to differ in constitution, the gemmules

(if I may again use the language of pangenesis) which are cast off from each varying part in the one sex

would be much more likely to possess the proper affinities for uniting with the tissues of the same sex, and

I was first led to infer that a relation of this kind exists, from the fact that whenever and in whatever manner

the adult male differs from the adult female, he differs in the same manner from the young of both sexes. The

generality of this fact is quite remarkable: it holds good with almost all mammals, birds, amphibians, and

fishes; also with many crustaceans, spiders, and some few insects, such as certain orthoptera and libellulae. In

all these cases the variations, through the accumulation of which the male acquired his proper masculine

characters, must have occurred at a somewhat late period of life; otherwise the young males would have been

similarly characterised; and conformably with our rule, the variations are transmitted to and developed in the

adult males alone. When, on the other hand, the adult male closely resembles the young of both sexes (these,

with rare exceptions, being alike), he generally resembles the adult female; and in most of these cases the

variations through which the young and old acquired their present characters, probably occurred, according to

our rule, during youth. But there is here room for doubt, for characters are sometimes transferred to the

offspring at an earlier age than that at which they first appeared in the parents, so that the parents may have

varied when adult, and have transferred their characters to their offspring whilst young. There are, moreover,

many animals, in which the two sexes closely resemble each other, and yet both differ from their young: and

here the characters of the adults must have been acquired late in life; nevertheless, these characters, in

apparent contradiction to our rule, are transferred to both sexes. We must not however, overlook the

possibility or even probability of successive variations of the same nature occurring, under exposure to

similar conditions, simultaneously in both sexes at a rather late period of life; and in this case the variations

would be transferred to the offspring of both sexes at a corresponding late age; and there would then be no

real contradiction to the rule that variations occurring late in life are transferred exclusively to the sex in

which they first appeared. This latter rule seems to hold true more generally than the second one, namely, that

variations which occur in either sex early in life tend to be transferred to both sexes. As it was obviously

impossible even to estimate in how large a number of cases throughout the animal kingdom these two

propositions held good, it occurred to me to investigate some striking or crucial instances, and to rely on the

An excellent case for investigation is afforded by the Deer family. In all the species, but one, the horns are

developed only in the males, though certainly transmitted through the females, and capable of abnormal

development in them. In the reindeer, on the other hand, the female is provided with horns; so that in this

species, the horns ought, according to our rule, to appear early in life, long before the two sexes are mature

and have come to differ much in constitution. In all the other species the horns ought to appear later in life,

which would lead to their development in that sex alone, in which they first appeared in the progenitor of the

whole Family. Now in seven species, belonging to distinct sections of the family and inhabiting different

regions, in which the stags alone bear horns, I find that the horns first appear at periods, varying from nine

months after birth in the roebuck, to ten, twelve or even more months in the stags of the six other and larger

species. (39. I am much obliged to Mr. Cupples for having made enquiries for me in regard to the Roebuck

and Red Deer of Scotland from Mr. Robertson, the experienced headforester to the Marquis of Breadalbane.

In regard to Fallowdeer, I have to thank Mr. Eyton and others for information. For the Cervus alces of N.

America, see 'Land and Water,' 1868, pp. 221 and 254; and for the C. Virginianus and strongyloceros of the

same continent, see J.D. Caton, in 'Ottawa Acad. of Nat. Sc.' 1868, p. 13. For Cervus Eldi of Pegu, see Lieut.

Beaven, 'Proccedings of the Zoological Society,' 1867, p. 762.) But with the reindeer the case is widely

different; for, as I hear from Prof. Nilsson, who kindly made special enquiries for me in Lapland, the horns

appear in the young animals within four or five weeks after birth, and at the same time in both sexes. So that

here we have a structure, developed at a most unusually early age in one species of the family, and likewise

In several kinds of antelopes, only the males are provided with horns, whilst in the greater number both sexes

bear horns. With respect to the period of development, Mr. Blyth informs me that there was at one time in the

Zoological Gardens a young koodoo (Ant. strepsiceros), of which the males alone are horned, and also the

young of a closelyallied species, the eland (Ant. oreas), in which both sexes are horned. Now it is in strict

conformity with our rule, that in the young male koodoo, although ten months old, the horns were remarkably

small, considering the size ultimately attained by them; whilst in the young male eland, although only three

months old, the horns were already very much larger than in the koodoo. It is also a noticeable fact that in the

pronghorned antelope (40. Antilocapra Americana. I have to thank Dr. Canfield for information with respect

to the horns of the female: see also his paper in 'Proceedings of the Zoological Society,' 1866, p. 109. Also

Owen, 'Anatomy of Vertebrates,' vol. iii. p. 627), only a few of the females, about one in five, have horns,

and these are in a rudimentary state, though sometimes above four inches long: so that as far as concerns the

possession of horns by the males alone, this species is in an intermediate condition, and the horns do not

appear until about five or six months after birth. Therefore in comparison with what little we know of the

development of the horns in other antelopes, and from what we do know with respect to the horns of deer,

cattle, etc., those of the pronghorned antelope appear at an intermediate period of life,that is, not very

early, as in cattle and sheep, nor very late, as in the larger deer and antelopes. The horns of sheep, goats, and

cattle, which are well developed in both sexes, though not quite equal in size, can be felt, or even seen, at

birth or soon afterwards. (41. I have been assured that the horns of the sheep in North Wales can always be

felt, and are sometimes even an inch in length, at birth. Youatt says ('Cattle,' 1834, p. 277), that the

prominence of the frontal bone in cattle penetrates the cutis at birth, and that the horny matter is soon formed

over it.) Our rule, however, seems to fail in some breeds of sheep, for instance merinos, in which the rams

alone are horned; for I cannot find on enquiry (42. I am greatly indebted to Prof. Victor Carus for having

made enquiries for me, from the highest authorities, with respect to the merino sheep of Saxony. On the

Guinea coast of Africa there is, however, a breed of sheep in which, as with merinos, the rams alone bear

horns; and Mr. Winwood Reade informs me that in one case observed by him, a young ram, born on Feb.

10th, first shewed horns on March 6th, so that in this instance, in conformity with rule, the development of

the horns occurred at a later period of life than in Welsh sheep, in which both sexes are horned.), that the

horns are developed later in life in this breed than in ordinary sheep in which both sexes are horned. But with

domesticated sheep the presence or absence of horns is not a firmly fixed character; for a certain proportion

of the merino ewes bear small horns, and some of the rams are hornless; and in most breeds hornless ewes are

Dr. W. Marshall has lately made a special study of the protuberances so common on the heads of birds (43.

'Uber die knochernen Schadelhocker der Vogel,' in the 'Niederland. Archiv fur Zoologie,' B.i. Heft 2, 1872.),

and he comes to the following conclusion:that with those species in which they are confined to the males,

they are developed late in life; whereas with those species in which they are common to the two sexes, they

are developed at a very early period. This is certainly a striking confirmation of my two laws of inheritance.

In most of the species of the splendid family of the Pheasants, the males differ conspicuously from the

females, and they acquire their ornaments at a rather late period of life. The eared pheasant (Crossoptilon

auritum), however, offers a remarkable exception, for both sexes possess the fine caudal plumes, the large

eartufts and the crimson velvet about the head; I find that all these characters appear very early in life in

accordance with rule. The adult male can, however, be distinguished from the adult female by the presence of

spurs; and conformably with our rule, these do not begin to be developed before the age of six months, as I

am assured by Mr. Bartlett, and even at this age, the two sexes can hardly be distinguished. (44. In the

common peacock (Pavo cristatus) the male alone possesses spurs, whilst both sexes of the Java Peacock (P.

muticus) offer the unusual case of being furnished with spurs. Hence I fully expected that in the latter species

they would have been developed earlier in life than in the common peacock; but M. Hegt of Amsterdam

informs me, that with young birds of the previous year, of both species, compared on April 23rd, 1869, there

was no difference in the development of the spurs. The spurs, however, were as yet represented merely by

slight knobs or elevations. I presume that I should have been informed if any difference in the rate of

development had been observed subsequently.) The male and female Peacock differ conspicuously from each

other in almost every part of their plumage, except in the elegant headcrest, which is common to both sexes;

and this is developed very early in life, long before the other ornaments, which are confined to the male. The

wildduck offers an analogous case, for the beautiful green speculum on the wings is common to both sexes,

though duller and somewhat smaller in the female, and it is developed early in life, whilst the curled

tailfeathers and other ornaments of the male are developed later. (45. In some other species of the Duck

family the speculum differs in a greater degree in the two sexes; but I have not been able to discover whether

its full development occurs later in life in the males of such species, than in the male of the common duck, as

ought to be the case according to our rule. With the allied Mergus cucullatus we have, however, a case of this

kind: the two sexes differ conspicuously in general plumage, and to a considerable degree in the speculum,

which is pure white in the male and greyishwhite in the female. Now the young males at first entirely

resemble the females, and have a greyishwhite speculum, which becomes pure white at an earlier age than

that at which the adult male acquires his other and more stronglymarked sexual differences: see Audubon,

'Ornithological Biography,' vol. iii. 1835, pp. 249250.) Between such extreme cases of close sexual

resemblance and wide dissimilarity, as those of the Crossoptilon and peacock, many intermediate ones could

be given, in which the characters follow our two rules in their order of development.

As most insects emerge from the pupal state in a mature condition, it is doubtful whether the period of

development can determine the transference of their characters to one or to both sexes. But we do not know

that the coloured scales, for instance, in two species of butterflies, in one of which the sexes differ in colour,

whilst in the other they are alike, are developed at the same relative age in the cocoon. Nor do we know

whether all the scales are simultaneously developed on the wings of the same species of butterfly, in which

certain coloured marks are confined to one sex, whilst others are common to both sexes. A difference of this

kind in the period of development is not so improbable as it may at first appear; for with the Orthoptera,

which assume their adult state, not by a single metamorphosis, but by a succession of moults, the young

males of some species at first resemble the females, and acquire their distinctive masculine characters only at

a later moult. Strictly analogous cases occur at the successive moults of certain male crustaceans.

We have as yet considered the transference of characters, relatively to their period of development, only in

species in a natural state; we will now turn to domesticated animals, and first touch on monstrosities and

diseases. The presence of supernumerary digits, and the absence of certain phalanges, must be determined at

an early embryonic periodthe tendency to profuse bleeding is at least congenital, as is probably

colourblindness yet these peculiarities, and other similar ones, are often limited in their transmission to

one sex; so that the rule that characters, developed at an early period, tend to be transmitted to both sexes,

here wholly fails. But this rule, as before remarked, does not appear to be nearly so general as the converse

one, namely, that characters which appear late in life in one sex are transmitted exclusively to the same sex.

From the fact of the above abnormal peculiarities becoming attached to one sex, long before the sexual

functions are active, we may infer that there must be some difference between the sexes at an extremely early

age. With respect to sexuallylimited diseases, we know too little of the period at which they originate, to

draw any safe conclusion. Gout, however, seems to fall under our rule, for it is generally caused by

intemperance during manhood, and is transmitted from the father to his sons in a much more marked manner

In the various domestic breeds of sheep, goats, and cattle, the males differ from their respective females in the

shape or development of their horns, forehead, mane, dewlap, tail, and hump on the shoulders; and these

peculiarities, in accordance with our rule, are not fully developed until a rather late period of life. The sexes

of dogs do not differ, except that in certain breeds, especially in the Scotch deerhound, the male is much

larger and heavier than the female; and, as we shall see in a future chapter, the male goes on increasing in size

to an unusually late period of life, which, according to rule, will account for his increased size being

transmitted to his male offspring alone. On the other hand, the tortoise shell colour, which is confined to

female cats, is quite distinct at birth, and this case violates the rule. There is a breed of pigeons in which the

males alone are streaked with black, and the streaks can be detected even in the nestlings; but they become

more conspicuous at each successive moult, so that this case partly opposes and partly supports the rule. With

the English Carrier and Pouter pigeons, the full development of the wattle and the crop occurs rather late in

life, and conformably with the rule, these characters are transmitted in full perfection to the males alone. The

following cases perhaps come within the class previously alluded to, in which both sexes have varied in the

same manner at a rather late period of life, and have consequently transferred their new characters to both

sexes at a corresponding late period; and if so, these cases are not opposed to our rule:there exist

subbreeds of the pigeon, described by Neumeister (46. 'Das Ganze der Taubenzucht,' 1837, ss. 21, 24. For

the case of the streaked pigeons, see Dr. Chapuis, 'Le pigeon voyageur Belge,' 1865, p. 87.), in which both

sexes change their colour during two or three moults (as is likewise the case with the Almond Tumbler);

nevertheless, these changes, though occurring rather late in life, are common to both sexes. One variety of the

With the breeds of the Fowl the inheritance of various characters by one or both sexes, seems generally

determined by the period at which such characters are developed. Thus in all the many breeds in which the

adult male differs greatly in colour from the female, as well as from the wild parentspecies, he differs also

from the young male, so that the newly acquired characters must have appeared at a rather late period of

life. On the other hand, in most of the breeds in which the two sexes resemble each other, the young are

coloured in nearly the same manner as their parents, and this renders it probable that their colours first

appeared early in life. We have instances of this fact in all black and white breeds, in which the young and

old of both sexes are alike; nor can it be maintained that there is something peculiar in a black or white

plumage, which leads to its transference to both sexes; for the males alone of many natural species are either

black or white, the females being differently coloured. With the socalled Cuckoo subbreeds of the fowl, in

which the feathers are transversely pencilled with dark stripes, both sexes and the chickens are coloured in

nearly the same manner. The laced plumage of the Sebright bantam is the same in both sexes, and in the

young chickens the wing feathers are distinctly, though imperfectly laced. Spangled Hamburgs, however,

offer a partial exception; for the two sexes, though not quite alike, resemble each other more closely than do

the sexes of the aboriginal parentspecies; yet they acquire their characteristic plumage late in life, for the

chickens are distinctly pencilled. With respect to other characters besides colour, in the wildparent species

and in most of the domestic breeds, the males alone possess a welldeveloped comb; but in the young of the

Spanish fowl it is largely developed at a very early age, and, in accordance with this early development in the

male, it is of unusual size in the adult female. In the Game breeds pugnacity is developed at a wonderfully

early age, of which curious proofs could be given; and this character is transmitted to both sexes, so that the

hens, from their extreme pugnacity, are now generally exhibited in separate pens. With the Polish breeds the

bony protuberance of the skull which supports the crest is partially developed even before the chickens are

hatched, and the crest itself soon begins to grow, though at first feebly (47. For full particulars and references

on all these points respecting the several breeds of the Fowl, see 'Variation of Animals and Plants under

Domestication,' vol. i. pp. 250, 256. In regard to the higher animals, the sexual differences which have arisen

under domestication are described in the same work under the head of each species.); and in this breed the

adults of both sexes are characterised by a great bony protuberance and an immense crest.

Finally, from what we have now seen of the relation which exists in many natural species and domesticated

races, between the period of the development of their characters and the manner of their transmissionfor

example, the striking fact of the early growth of the horns in the reindeer, in which both sexes bear horns, in

comparison with their much later growth in the other species in which the male alone bears hornswe may

conclude that one, though not the sole cause of characters being exclusively inherited by one sex, is their

development at a late age. And secondly, that one, though apparently a less efficient cause of characters being

inherited by both sexes, is their development at an early age, whilst the sexes differ but little in constitution. It

appears, however, that some difference must exist between the sexes even during a very early embryonic

period, for characters developed at this age not rarely become attached to one sex.

From the foregoing discussion on the various laws of inheritance, we learn that the characters of the parents

often, or even generally, tend to become developed in the offspring of the same sex, at the same age, and

periodically at the same season of the year, in which they first appeared in the parents. But these rules, owing

to unknown causes, are far from being fixed. Hence during the modification of a species, the successive

changes may readily be transmitted in different ways; some to one sex, and some to both; some to the

offspring at one age, and some to the offspring at all ages. Not only are the laws of inheritance extremely

complex, but so are the causes which induce and govern variability. The variations thus induced are

preserved and accumulated by sexual selection, which is in itself an extremely complex affair, depending, as

it does, on the ardour in love, the courage, and the rivalry of the males, as well as on the powers of

perception, the taste, and will of the female. Sexual selection will also be largely dominated by natural

selection tending towards the general welfare of the species. Hence the manner in which the individuals of

either or both sexes have been affected through sexual selection cannot fail to be complex in the highest

When variations occur late in life in one sex, and are transmitted to the same sex at the same age, the other

sex and the young are left unmodified. When they occur late in life, but are transmitted to both sexes at the

same age, the young alone are left unmodified. Variations, however, may occur at any period of life in one

sex or in both, and be transmitted to both sexes at all ages, and then all the individuals of the species are

similarly modified. In the following chapters it will be seen that all these cases frequently occur in nature.

Sexual selection can never act on any animal before the age for reproduction arrives. From the great

eagerness of the male it has generally acted on this sex and not on the females. The males have thus become

provided with weapons for fighting with their rivals, with organs for discovering and securely holding the

female, and for exciting or charming her. When the sexes differ in these respects, it is also, as we have seen,

an extremely general law that the adult male differs more or less from the young male; and we may conclude

from this fact that the successive variations, by which the adult male became modified, did not generally

occur much before the age for reproduction. Whenever some or many of the variations occurred early in life,

the young males would partake more or less of the characters of the adult males; and differences of this kind

It is probable that young male animals have often tended to vary in a manner which would not only have been

of no use to them at an early age, but would have been actually injuriousas by acquiring bright colours,

which would render them conspicuous to their enemies, or by acquiring structures, such as great horns, which

would expend much vital force in their development. Variations of this kind occurring in the young males

would almost certainly be eliminated through natural selection. With the adult and experienced males, on the

other hand, the advantages derived from the acquisition of such characters, would more than counterbalance

As variations which give to the male a better chance of conquering other males, or of finding, securing, or

charming the opposite sex, would, if they happened to arise in the female, be of no service to her, they would

not be preserved in her through sexual selection. We have also good evidence with domesticated animals, that

variations of all kinds are, if not carefully selected, soon lost through intercrossing and accidental deaths.

Consequently in a state of nature, if variations of the above kind chanced to arise in the female line, and to be

transmitted exclusively in this line, they would be extremely liable to be lost. If, however, the females varied

and transmitted their newly acquired characters to their offspring of both sexes, the characters which were

advantageous to the males would be preserved by them through sexual selection, and the two sexes would in

consequence be modified in the same manner, although such characters were of no use to the females: but I

shall hereafter have to recur to these more intricate contingencies. Lastly, the females may acquire, and

As variations occurring later in life, and transmitted to one sex alone, have incessantly been taken advantage

of and accumulated through sexual selection in relation to the reproduction of the species; therefore it

appears, at first sight, an unaccountable fact that similar variations have not frequently been accumulated

through natural selection, in relation to the ordinary habits of life. If this had occurred, the two sexes would

often have been differently modified, for the sake, for instance, of capturing prey or of escaping from danger.

Differences of this kind between the two sexes do occasionally occur, especially in the lower classes. But this

implies that the two sexes follow different habits in their struggles for existence, which is a rare circumstance

with the higher animals. The case, however, is widely different with the reproductive functions, in which

respect the sexes necessarily differ. For variations in structure which are related to these functions, have often

proved of value to one sex, and from having arisen at a late period of life, have been transmitted to one sex

alone; and such variations, thus preserved and transmitted, have given rise to secondary sexual characters.

In the following chapters, I shall treat of the secondary sexual characters in animals of all classes, and shall

endeavour in each case to apply the principles explained in the present chapter. The lowest classes will detain

us for a very short time, but the higher animals, especially birds, must be treated at considerable length. It

should be borne in mind that for reasons already assigned, I intend to give only a few illustrative instances of

the innumerable structures by the aid of which the male finds the female, or, when found, holds her. On the

other hand, all structures and instincts by the aid of which the male conquers other males, and by which he

allures or excites the female, will be fully discussed, as these are in many ways the most interesting.

As no one, as far as I can discover, has paid attention to the relative numbers of the two sexes throughout the

animal kingdom, I will here give such materials as I have been able to collect, although they are extremely

imperfect. They consist in only a few instances of actual enumeration, and the numbers are not very large. As

the proportions are known with certainty only in mankind, I will first give them as a standard of comparison.

In England during ten years (from 1857 to 1866) the average number of children born alive yearly was

707,120, in the proportion of 104.5 males to 100 females. But in 1857 the male births throughout England

were as 105.2, and in 1865 as 104.0 to 100. Looking to separate districts, in Buckinghamshire (where about

5000 children are annually born) the MEAN proportion of male to female births, during the whole period of

the above ten years, was as 102.8 to 100; whilst in N. Wales (where the average annual births are 12,873) it

was as high as 106.2 to 100. Taking a still smaller district, viz., Rutlandshire (where the annual births average

only 739), in 1864 the male births were as 114.6, and in 1862 as only 97.0 to 100; but even in this small

district the average of the 7385 births during the whole ten years, was as 104.5 to 100: that is in the same

ratio as throughout England. (48. 'Twentyninth Annual Report of the Registrar General for 1866.' In this

report (p. xii.) a special decennial table is given.) The proportions are sometimes slightly disturbed by

unknown causes; thus Prof. Faye states "that in some districts of Norway there has been during a decennial

period a steady deficiency of boys, whilst in others the opposite condition has existed." In France during

fortyfour years the male to the female births have been as 106.2 to 100; but during this period it has

occurred five times in one department, and six times in another, that the female births have exceeded the

males. In Russia the average proportion is as high as 108.9, and in Philadelphia in the United States as 110.5

to 100. (49. For Norway and Russia, see abstract of Prof. Faye's researches, in 'British and Foreign

MedicoChirurg. Review,' April 1867, pp. 343, 345. For France, the 'Annuaire pour l'An 1867,' p. 213. For

Philadelphia, Dr. Stockton Hough, 'Social Science Assoc.' 1874. For the Cape of Good Hope, Quetelet as

quoted by Dr. H.H. Zouteveen, in the Dutch Translation of this work (vol. i. p. 417), where much information

is given on the proportion of the sexes.) The average for Europe, deduced by Bickes from about seventy

million births, is 106 males to 100 females. On the other hand, with white children born at the Cape of Good

Hope, the proportion of males is so low as to fluctuate during successive years between 90 and 99 males for

every 100 females. It is a singular fact that with Jews the proportion of male births is decidedly larger than

with Christians: thus in Prussia the proportion is as 113, in Breslau as 114, and in Livonia as 120 to 100; the

Christian births in these countries being the same as usual, for instance, in Livonia as 104 to 100. (50. In

regard to the Jews, see M. Thury, 'La Loi de Production des Sexes,' 1863, p. 25.)

Prof. Faye remarks that "a still greater preponderance of males would be met with, if death struck both sexes

in equal proportion in the womb and during birth. But the fact is, that for every 100 stillborn females, we

have in several countries from 134.6 to 144.9 stillborn males. During the first four or five years of life, also,

more male children die than females, for example in England, during the first year, 126 boys die for every

100 girlsa proportion which in France is still more unfavourable." (51. 'British and Foreign

MedicoChirurg. Review,' April 1867, p. 343. Dr. Stark also remarks ('Tenth Annual Report of Births,

Deaths, etc., in Scotland,' 1867, p. xxviii.) that "These examples may suffice to show that, at almost every

stage of life, the males in Scotland have a greater liability to death and a higher deathrate than the females.

The fact, however, of this peculiarity being most strongly developed at that infantile period of life when the

dress, food, and general treatment of both sexes are alike, seems to prove that the higher male deathrate is

an impressed, natural, and constitutional peculiarity due to sex alone.") Dr. Stockton Hough accounts for

these facts in part by the more frequent defective development of males than of females. We have before seen

that the male sex is more variable in structure than the female; and variations in important organs would

generally be injurious. But the size of the body, and especially of the head, being greater in male than female

infants is another cause: for the males are thus more liable to be injured during parturition. Consequently the

stillborn males are more numerous; and, as a highly competent judge, Dr. Crichton Browne (52. 'West

Riding Lunatic Asylum Reports,' vol. i. 1871, p. 8. Sir J. Simpson has proved that the head of the male infant

exceeds that of the female by 3/8ths of an inch in circumference, and by 1/8th in transverse diameter.

Quetelet has shewn that woman is born smaller than man; see Dr. Duncan, 'Fecundity, Fertility, and Sterility,'

1871, p. 382.), believes, male infants often suffer in health for some years after birth. Owing to this excess in

the deathrate of male children, both at birth and for some time subsequently, and owing to the exposure of

grown men to various dangers, and to their tendency to emigrate, the females in all oldsettled countries,

where statistical records have been kept, are found to preponderate considerably over the males. (53. With the

savage Guaranys of Paraguay, according to the accurate Azara ('Voyages dans l'Amerique merid.' tom. ii.

It seems at first sight a mysterious fact that in different nations, under different conditions and climates, in

Naples, Prussia, Westphalia, Holland, France, England and the United States, the excess of male over female

births is less when they are illegitimate than when legitimate. (54. Babbage, 'Edinburgh Journal of Science,'

1829, vol. i. p. 88; also p. 90, on stillborn children. On illegitimate children in England, see 'Report of

RegistrarGeneral for 1866,' p. xv.) This has been explained by different writers in many different ways, as

from the mothers being generally young, from the large proportion of first pregnancies, etc. But we have seen

that male infants, from the large size of their heads, suffer more than female infants during parturition; and as

the mothers of illegitimate children must be more liable than other women to undergo bad labours, from

various causes, such as attempts at concealment by tight lacing, hard work, distress of mind, etc., their male

infants would proportionably suffer. And this probably is the most efficient of all the causes of the proportion

of males to females born alive being less amongst illegitimate children than amongst the legitimate. With

most animals the greater size of the adult male than of the female, is due to the stronger males having

conquered the weaker in their struggles for the possession of the females, and no doubt it is owing to this fact

that the two sexes of at least some animals differ in size at birth. Thus we have the curious fact that we may

attribute the more frequent deaths of male than female infants, especially amongst the illegitimate, at least in

It has often been supposed that the relative age of the two parents determine the sex of the offspring; and

Prof. Leuckart (55. Leuckart, in Wagner 'Handworterbuch der Phys.' B. iv. 1853, s. 774.) has advanced what

he considers sufficient evidence, with respect to man and certain domesticated animals, that this is one

important though not the sole factor in the result. So again the period of impregnation relatively to the state of

the female has been thought by some to be the efficient cause; but recent observations discountenance this

belief. According to Dr. Stockton Hough (56. 'Social Science Association of Philadelphia,' 1874.), the season

of the year, the poverty or wealth of the parents, residence in the country or in cities, the crossing of foreign

immigrants, etc., all influence the proportion of the sexes. With mankind, polygamy has also been supposed

to lead to the birth of a greater proportion of female infants; but Dr. J. Campbell (57. 'Anthropological

Review,' April 1870, p. cviii.) carefully attended to this subject in the harems of Siam, and concludes that the

proportion of male to female births is the same as from monogamous unions. Hardly any animal has been

rendered so highly polygamous as the English racehorse, and we shall immediately see that his male and

female offspring are almost exactly equal in number. I will now give the facts which I have collected with

respect to the proportional numbers of the sexes of various animals; and will then briefly discuss how far

Mr. Tegetmeier has been so kind as to tabulate for me from the 'Racing Calendar' the births of racehorses

during a period of twentyone years, viz., from 1846 to 1867; 1849 being omitted, as no returns were that

year published. The total births were 25,560 (58. During eleven years a record was kept of the number of

mares which proved barren or prematurely slipped their foals; and it deserves notice, as shewing how infertile

these highly nurtured and rather closelyinterbred animals have become, that not far from onethird of the

mares failed to produce living foals. Thus during 1866, 809 male colts and 816 female colts were born, and

743 mares failed to produce offspring. During 1867, 836 males and 902 females were born, and 794 mares

failed.), consisting of 12,763 males and 12,797 females, or in the proportion of 99.7 males to 100 females. As

these numbers are tolerably large, and as they are drawn from all parts of England, during several years, we

may with much confidence conclude that with the domestic horse, or at least with the racehorse, the two

sexes are produced in almost equal numbers. The fluctuations in the proportions during successive years are

closely like those which occur with mankind, when a small and thinlypopulated area is considered; thus in

1856 the male horses were as 107.1, and in 1867 as only 92.6 to 100 females. In the tabulated returns the

proportions vary in cycles, for the males exceeded the females during six successive years; and the females

exceeded the males during two periods each of four years; this, however, may be accidental; at least I can

detect nothing of the kind with man in the decennial table in the Registrar's Report for 1866.

During a period of twelve years, from 1857 to 1868, the births of a large number of greyhounds, throughout

England, were sent to the 'Field' newspaper; and I am again indebted to Mr. Tegetmeier for carefully

tabulating the results. The recorded births were 6878, consisting of 3605 males and 3273 females, that is, in

the proportion of 110.1 males to 100 females. The greatest fluctuations occurred in 1864, when the proportion

was as 95.3 males, and in 1867, as 116.3 males to 100 females. The above average proportion of 110.1 to 100

is probably nearly correct in the case of the greyhound, but whether it would hold with other domesticated

breeds is in some degree doubtful. Mr. Cupples has enquired from several great breeders of dogs, and finds

that all without exception believe that females are produced in excess; but he suggests that this belief may

have arisen from females being less valued, and from the consequent disappointment producing a stronger

The sexes of sheep are not ascertained by agriculturists until several months after birth, at the period when the

males are castrated; so that the following returns do not give the proportions at birth. Moreover, I find that

several great breeders in Scotland, who annually raise some thousand sheep, are firmly convinced that a

larger proportion of males than of females die during the first year or two. Therefore the proportion of males

would be somewhat larger at birth than at the age of castration. This is a remarkable coincidence with what,

as we have seen, occurs with mankind, and both cases probably depend on the same cause. I have received

returns from four gentlemen in England who have bred Lowland sheep, chiefly Leicesters, during the last ten

to sixteen years; they amount altogether to 8965 births, consisting of 4407 males and 4558 females; that is in

the proportion of 96.7 males to 100 females. With respect to Cheviot and blackfaced sheep bred in Scotland,

I have received returns from six breeders, two of them on a large scale, chiefly for the years 18671869, but

some of the returns extend back to 1862. The total number recorded amounts to 50,685, consisting of 25,071

males and 25,614 females or in the proportion of 97.9 males to 100 females. If we take the English and

Scotch returns together, the total number amounts to 59,650, consisting of 29,478 males and 30,172 females,

or as 97.7 to 100. So that with sheep at the age of castration the females are certainly in excess of the males,

but probably this would not hold good at birth. (59. I am much indebted to Mr. Cupples for having procured

for me the above returns from Scotland, as well as some of the following returns on cattle. Mr. R. Elliot, of

Laighwood, first called my attention to the premature deaths of the males, a statement subsequently

confirmed by Mr. Aitchison and others. To this latter gentleman, and to Mr. Payan, I owe my thanks for large

Of CATTLE I have received returns from nine gentlemen of 982 births, too few to be trusted; these consisted

of 477 bullcalves and 505 cowcalves; i.e., in the proportion of 94.4 males to 100 females. The Rev. W.D.

Fox informs me that in 1867 out of 34 calves born on a farm in Derbyshire only one was a bull. Mr. Harrison

Weir has enquired from several breeders of PIGS, and most of them estimate the male to the female births as

about 7 to 6. This same gentleman has bred RABBITS for many years, and has noticed that a far greater

Of mammalia in a state of nature I have been able to learn very little. In regard to the common rat, I have

received conflicting statements. Mr. R. Elliot, of Laighwood, informs me that a ratcatcher assured him that

he had always found the males in great excess, even with the young in the nest. In consequence of this, Mr.

Elliot himself subsequently examined some hundred old ones, and found the statement true. Mr. F. Buckland

has bred a large number of white rats, and he also believes that the males greatly exceed the females. In

regard to Moles, it is said that "the males are much more numerous than the females" (60. Bell, 'History of

British Quadrupeds,' p. 100.): and as the catching of these animals is a special occupation, the statement may

perhaps be trusted. Sir A. Smith, in describing an antelope of S. Africa (61. 'Illustrations of the Zoology of S.

Africa,' 1849, pl. 29.) (Kobus ellipsiprymnus), remarks, that in the herds of this and other species, the males

are few in number compared with the females: the natives believe that they are born in this proportion; others

believe that the younger males are expelled from the herds, and Sir A. Smith says, that though he has himself

never seen herds consisting of young males alone, others affirm that this does occur. It appears probable that

the young when expelled from the herd, would often fall a prey to the many beasts of prey of the country.

With respect to the FOWL, I have received only one account, namely, that out of 1001 chickens of a

highlybred stock of Cochins, reared during eight years by Mr. Stretch, 487 proved males and 514 females;

i.e., as 94.7 to 100. In regard to domestic pigeons there is good evidence either that the males are produced in

excess, or that they live longer; for these birds invariably pair, and single males, as Mr. Tegetmeier informs

me, can always be purchased cheaper than females. Usually the two birds reared from the two eggs laid in the

same nest are a male and a female; but Mr. Harrison Weir, who has been so large a breeder, says that he has

often bred two cocks from the same nest, and seldom two hens; moreover, the hen is generally the weaker of

With respect to birds in a state of nature, Mr. Gould and others (62. Brehm ('Thierleben,' B. iv. s. 990) comes

to the same conclusion.) are convinced that the males are generally the more numerous; and as the young

males of many species resemble the females, the latter would naturally appear to be the more numerous.

Large numbers of pheasants are reared by Mr. Baker of Leadenhall from eggs laid by wild birds, and he

informs Mr. Jenner Weir that four or five males to one female are generally produced. An experienced

observer remarks (63. On the authority of L. Lloyd, 'Game Birds of Sweden,' 1867, pp. 12, 132.), that in

Scandinavia the broods of the capercailzie and blackcock contain more males than females; and that with

the Dalripa (a kind of ptarmigan) more males than females attend the leks or places of courtship; but this

latter circumstance is accounted for by some observers by a greater number of hen birds being killed by

vermin. From various facts given by White of Selborne (64. 'Nat. Hist. of Selborne,' letter xxix. edit. of 1825,

vol. i. p. 139.), it seems clear that the males of the partridge must be in considerable excess in the south of

England; and I have been assured that this is the case in Scotland. Mr. Weir on enquiring from the dealers,

who receive at certain seasons large numbers of ruffs (Machetes pugnax), was told that the males are much

the more numerous. This same naturalist has also enquired for me from the birdcatchers, who annually catch

an astonishing number of various small species alive for the London market, and he was unhesitatingly

answered by an old and trustworthy man, that with the chaffinch the males are in large excess: he thought as

high as 2 males to 1 female, or at least as high as 5 to 3. (65. Mr. Jenner Weir received similar information,

on making enquiries during the following year. To shew the number of living chaffinches caught, I may

mention that in 1869 there was a match between two experts, and one man caught in a day 62, and another

40, male chaffinches. The greatest number ever caught by one man in a single day was 70.) The males of the

blackbird, he likewise maintained, were by far the more numerous, whether caught by traps or by netting at

night. These statements may apparently be trusted, because this same man said that the sexes are about equal

with the lark, the twite (Linaria montana), and goldfinch. On the other hand, he is certain that with the

common linnet, the females preponderate greatly, but unequally during different years; during some years he

has found the females to the males as four to one. It should, however, be borne in mind, that the chief season

for catching birds does not begin till September, so that with some species partial migrations may have

begun, and the flocks at this period often consist of hens alone. Mr. Salvin paid particular attention to the

sexes of the hummingbirds in Central America, and is convinced that with most of the species the males are

in excess; thus one year he procured 204 specimens belonging to ten species, and these consisted of 166

males and of only 38 females. With two other species the females were in excess: but the proportions

apparently vary either during different seasons or in different localities; for on one occasion the males of

Campylopterus hemileucurus were to the females as 5 to 2, and on another occasion (66. 'Ibis,' vol. ii. p. 260,

as quoted in Gould's 'Trochilidae,' 1861, p. 52. For the foregoing proportions, I am indebted to Mr. Salvin for

a table of his results.) in exactly the reversed ratio. As bearing on this latter point, I may add, that Mr. Powys

found in Corfu and Epirus the sexes of the chaffinch keeping apart, and "the females by far the most

numerous"; whilst in Palestine Mr. Tristram found "the male flocks appearing greatly to exceed the female in

number." (67. 'Ibis,' 1860, p. 137; and 1867, p. 369.) So again with the Quiscalus major, Mr. G. Taylor says,

that in Florida there were "very few females in proportion to the males," (68. 'Ibis,' 1862, p. 187.) whilst in

Honduras the proportion was the other way, the species there having the character of a polygamist.

With fish the proportional numbers of the sexes can be ascertained only by catching them in the adult or

nearly adult state; and there are many difficulties in arriving at any just conclusion. (69. Leuckart quotes

Bloch (Wagner, 'Handworterbuch der Phys.' B. iv. 1853, s. 775), that with fish there are twice as many males

as females.) Infertile females might readily be mistaken for males, as Dr. Gunther has remarked to me in

regard to trout. With some species the males are believed to die soon after fertilising the ova. With many

species the males are of much smaller size than the females, so that a large number of males would escape

from the same net by which the females were caught. M. Carbonnier (70. Quoted in the 'Farmer,' March 18,

1869, p. 369.), who has especially attended to the natural history of the pike (Esox lucius), states that many

males, owing to their small size, are devoured by the larger females; and he believes that the males of almost

all fish are exposed from this same cause to greater danger than the females. Nevertheless, in the few cases in

which the proportional numbers have been actually observed, the males appear to be largely in excess. Thus

Mr. R. Buist, the superintendent of the Stormontfield experiments, says that in 1865, out of 70 salmon first

landed for the purpose of obtaining the ova, upwards of 60 were males. In 1867 he again "calls attention to

the vast disproportion of the males to the females. We had at the outset at least ten males to one female."

Afterwards females sufficient for obtaining ova were procured. He adds, "from the great proportion of the

males, they are constantly fighting and tearing each other on the spawningbeds." (71. 'The Stormontfield

Piscicultural Experiments,' 1866, p. 23. The 'Field' newspaper, June 29, 1867.) This disproportion, no doubt,

can be accounted for in part, but whether wholly is doubtful, by the males ascending the rivers before the

females. Mr. F. Buckland remarks in regard to trout, that "it is a curious fact that the males preponderate very

largely in number over the females. It INVARIABLY happens that when the first rush of fish is made to the

net, there will be at least seven or eight males to one female found captive. I cannot quite account for this;

either the males are more numerous than the females, or the latter seek safety by concealment rather than

flight." He then adds, that by carefully searching the banks sufficient females for obtaining ova can be found.

(72. 'Land and Water,' 1868, p. 41.) Mr. H. Lee informs me that out of 212 trout, taken for this purpose in

The males of the Cyprinidae likewise seem to be in excess; but several members of this Family, viz., the carp,

tench, bream and minnow, appear regularly to follow the practice, rare in the animal kingdom, of polyandry;

for the female whilst spawning is always attended by two males, one on each side, and in the case of the

bream by three or four males. This fact is so well known, that it is always recommended to stock a pond with

two male tenches to one female, or at least with three males to two females. With the minnow, an excellent

observer states, that on the spawningbeds the males are ten times as numerous as the females; when a

female comes amongst the males, "she is immediately pressed closely by a male on each side; and when they

have been in that situation for a time, are superseded by other two males." (73. Yarrell, 'Hist. British Fishes,'

vol. i. 1826, p. 307; on the Cyprinus carpio, p. 331; on the Tinca vulgaris, p. 331; on the Abramis brama, p.

336. See, for the minnow (Leuciscus phoxinus), 'Loudon's Magazine of Natural History,' vol. v. 1832, p.

In this great Class, the Lepidoptera almost alone afford means for judging of the proportional numbers of the

sexes; for they have been collected with special care by many good observers, and have been largely bred

from the egg or caterpillar state. I had hoped that some breeders of silkmoths might have kept an exact

record, but after writing to France and Italy, and consulting various treatises, I cannot find that this has ever

been done. The general opinion appears to be that the sexes are nearly equal, but in Italy, as I hear from

Professor Canestrini, many breeders are convinced that the females are produced in excess. This same

naturalist, however, informs me, that in the two yearly broods of the Ailanthus silkmoth (Bombyx cynthia),

the males greatly preponderate in the first, whilst in the second the two sexes are nearly equal, or the females

In regard to Butterflies in a state of nature, several observers have been much struck by the apparently

enormous preponderance of the males. (74. Leuckart quotes Meinecke (Wagner, 'Handworterbuch der Phys.'

B. iv. 1853, s. 775) that the males of Butterflies are three or four times as numerous as the females.) Thus Mr.

Bates (75. 'The Naturalist on the Amazons,' vol. ii. 1863, pp. 228, 347.), in speaking of several species, about

a hundred in number, which inhabit the upper Amazons, says that the males are much more numerous than

the females, even in the proportion of a hundred to one. In North America, Edwards, who had great

experience, estimates in the genus Papilio the males to the females as four to one; and Mr. Walsh, who

informed me of this statement, says that with P. turnus this is certainly the case. In South Africa, Mr. R.

Trimen found the males in excess in 19 species (76. Four of these cases are given by Mr. Trimen in his

'Rhopalocera Africae Australis.'); and in one of these, which swarms in open places, he estimated the number

of males as fifty to one female. With another species, in which the males are numerous in certain localities,

he collected only five females during seven years. In the island of Bourbon, M. Maillard states that the males

of one species of Papilio are twenty times as numerous as the females. (77. Quoted by Trimen, 'Transactions

of the Ent. Society,' vol. v. part iv. 1866, p. 330.) Mr. Trimen informs me that as far as he has himself seen, or

heard from others, it is rare for the females of any butterfly to exceed the males in number; but three South

African species perhaps offer an exception. Mr. Wallace (78. 'Transactions, Linnean Society,' vol. xxv. p. 37.)

states that the females of Ornithoptera croesus, in the Malay archipelago, are more common and more easily

caught than the males; but this is a rare butterfly. I may here add, that in Hyperythra, a genus of moths,

Guenee says, that from four to five females are sent in collections from India for one male.

When this subject of the proportional numbers of the sexes of insects was brought before the Entomological

Society (79. 'Proceedings, Entomological Society,' Feb. 17, 1868.), it was generally admitted that the males

of most Lepidoptera, in the adult or imago state, are caught in greater numbers than the females: but this fact

was attributed by various observers to the more retiring habits of the females, and to the males emerging

earlier from the cocoon. This latter circumstance is well known to occur with most Lepidoptera, as well as

with other insects. So that, as M. Personnat remarks, the males of the domesticated Bombyx Yamamai, are

useless at the beginning of the season, and the females at the end, from the want of mates. (80. Quoted by Dr.

Wallace in 'Proceedings, Entomological Society,' 3rd series, vol. v. 1867, p. 487.) I cannot, however,

persuade myself that these causes suffice to explain the great excess of males, in the above cases of certain

butterflies which are extremely common in their native countries. Mr. Stainton, who has paid very close

attention during many years to the smaller moths, informs me that when he collected them in the imago state,

he thought that the males were ten times as numerous as the females, but that since he has reared them on a

large scale from the caterpillar state, he is convinced that the females are the more numerous. Several

entomologists concur in this view. Mr. Doubleday, however, and some others, take an opposite view, and are

convinced that they have reared from the eggs and caterpillars a larger proportion of males than of females.

Besides the more active habits of the males, their earlier emergence from the cocoon, and in some cases their

frequenting more open stations, other causes may be assigned for an apparent or real difference in the

proportional numbers of the sexes of Lepidoptera, when captured in the imago state, and when reared from

the egg or caterpillar state. I hear from Professor Canestrini, that it is believed by many breeders in Italy, that

the female caterpillar of the silkmoth suffers more from the recent disease than the male; and Dr. Staudinger

informs me that in rearing Lepidoptera more females die in the cocoon than males. With many species the

female caterpillar is larger than the male, and a collector would naturally choose the finest specimens, and

thus unintentionally collect a larger number of females. Three collectors have told me that this was their

practice; but Dr. Wallace is sure that most collectors take all the specimens which they can find of the rarer

kinds, which alone are worth the trouble of rearing. Birds when surrounded by caterpillars would probably

devour the largest; and Professor Canestrini informs me that in Italy some breeders believe, though on

insufficient evidence, that in the first broods of the Ailanthus silkmoth, the wasps destroy a larger number of

the female than of the male caterpillars. Dr. Wallace further remarks that female caterpillars, from being

larger than the males, require more time for their development, and consume more food and moisture: and

thus they would be exposed during a longer time to danger from ichneumons, birds, etc., and in times of

scarcity would perish in greater numbers. Hence it appears quite possible that in a state of nature, fewer

female Lepidoptera may reach maturity than males; and for our special object we are concerned with their

The manner in which the males of certain moths congregate in extraordinary numbers round a single female,

apparently indicates a great excess of males, though this fact may perhaps be accounted for by the earlier

emergence of the males from their cocoons. Mr. Stainton informs me that from twelve to twenty males, may

often be seen congregated round a female Elachista rufocinerea. It is well known that if a virgin Lasiocampa

quercus or Saturnia carpini be exposed in a cage, vast numbers of males collect round her, and if confined in

a room will even come down the chimney to her. Mr. Doubleday believes that he has seen from fifty to a

hundred males of both these species attracted in the course of a single day by a female in confinement. In the

Isle of Wight Mr. Trimen exposed a box in which a female of the Lasiocampa had been confined on the

previous day, and five males soon endeavoured to gain admittance. In Australia, Mr. Verreaux, having placed

the female of a small Bombyx in a box in his pocket, was followed by a crowd of males, so that about 200

entered the house with him. (81. Blanchard, 'Metamorphoses, Moeurs des Insectes,' 1868, pp. 225226.)

Mr. Doubleday has called my attention to M. Staudinger's (82. 'LepidopterenDoubletten Liste,' Berlin, No.

x. 1866.) list of Lepidoptera, which gives the prices of the males and females of 300 species or well marked

varieties of butterflies (Rhopalocera). The prices for both sexes of the very common species are of course the

same; but in 114 of the rarer species they differ; the males being in all cases, excepting one, the cheaper. On

an average of the prices of the 113 species, the price of the male to that of the female is as 100 to 149; and

this apparently indicates that inversely the males exceed the females in the same proportion. About 2000

species or varieties of moths (Heterocera) are catalogued, those with wingless females being here excluded

on account of the difference in habits between the two sexes: of these 2000 species, 141 differ in price

according to sex, the males of 130 being cheaper, and those of only 11 being dearer than the females. The

average price of the males of the 130 species, to that of the females, is as 100 to 143. With respect to the

butterflies in this priced list, Mr. Doubleday thinks (and no man in England has had more experience), that

there is nothing in the habits of the species which can account for the difference in the prices of the two

sexes, and that it can be accounted for only by an excess in the number of the males. But I am bound to add

that Dr. Staudinger informs me, that he is himself of a different opinion. He thinks that the less active habits

of the females and the earlier emergence of the males will account for his collectors securing a larger number

of males than of females, and consequently for the lower prices of the former. With respect to specimens

reared from the caterpillarstate, Dr. Staudinger believes, as previously stated, that a greater number of

females than of males die whilst confined to the cocoons. He adds that with certain species one sex seems to

Of direct observations on the sexes of Lepidoptera, reared either from eggs or caterpillars, I have received

So that in these eight lots of cocoons and eggs, males were produced in excess. Taken together the proportion

of males is as 122.7 to 100 females. But the numbers are hardly large enough to be trustworthy.

On the whole, from these various sources of evidence, all pointing in the same direction, I infer that with

most species of Lepidoptera, the mature males generally exceed the females in number, whatever the

Males Females The Rev. J. Hellins* of Exeter reared, during 1868, imagos of 73 species, which consisted of

Mr. Albert Jones of Eltham reared, during 1868, imagos of 9 species, which consisted of 159 126

Mr. Buckler of Emsworth, Hants, during 1869, reared imagos from 74 species, consisting of 180 169

Dr. Wallace raised, from cocoons of Bombyx Pernyi sent from China, during 1869 224 123

Dr. Wallace raised, during 1868 and 1869, from two lots of cocoons of Bombyx yamamai 52 46

(*83. This naturalist has been so kind as to send me some results from former years, in which the females

seemed to preponderate; but so many of the figures were estimates, that I found it impossible to tabulate

With reference to the other Orders of insects, I have been able to collect very little reliable information. With

the stagbeetle (Lucanus cervus) "the males appear to be much more numerous than the females"; but when,

as Cornelius remarked during 1867, an unusual number of these beetles appeared in one part of Germany, the

females appeared to exceed the males as six to one. With one of the Elateridae, the males are said to be much

more numerous than the females, and "two or three are often found united with one female (84. Gunther's

'Record of Zoological Literature,' 1867, p. 260. On the excess of female Lucanus, ibid, p. 250. On the males

of Lucanus in England, Westwood,' 'Modern Classification of Insects,' vol. i. p. 187. On the Siagonium, ibid.

p. 172.); so that here polyandry seems to prevail." With Siagonium (Staphylinidae), in which the males are

furnished with horns, "the females are far more numerous than the opposite sex." Mr. Janson stated at the

Entomological Society that the females of the bark feeding Tomicus villosus are so common as to be a

It is hardly worth while saying anything about the proportion of the sexes in certain species and even groups

of insects, for the males are unknown or very rare, and the females are parthenogenetic, that is, fertile without

sexual union; examples of this are afforded by several of the Cynipidae. (85. Walsh in 'The American

Entomologist,' vol. i. 1869, p. 103. F. Smith, 'Record of Zoological Lit.' 1867, p. 328.) In all the gallmaking

Cynipidae known to Mr. Walsh, the females are four or five times as numerous as the males; and so it is, as

he informs me, with the gallmaking Cecidomyiidae (Diptera). With some common species of Sawflies

(Tenthredinae) Mr. F. Smith has reared hundreds of specimens from larvae of all sizes, but has never reared a

single male; on the other hand, Curtis says (86. 'Farm Insects,' pp. 4546.), that with certain species (Athalia),

bred by him, the males were to the females as six to one; whilst exactly the reverse occurred with the mature

insects of the same species caught in the fields. In the family of bees, Hermann Muller (87. 'Anwendung der

Darwin'schen Lehre,' Verh. d. n. Jahrg., xxiv.), collected a large number of specimens of many species, and

reared others from the cocoons, and counted the sexes. He found that the males of some species greatly

exceeded the females in number; in others the reverse occurred; and in others the two sexes were nearly

equal. But as in most cases the males emerge from the cocoons before the females, they are at the

commencement of the breedingseason practically in excess. Muller also observed that the relative number

of the two sexes in some species differed much in different localities. But as H. Muller has himself remarked

to me, these remarks must be received with some caution, as one sex might more easily escape observation

than the other. Thus his brother Fritz Muller has noticed in Brazil that the two sexes of the same species of

bee sometimes frequent different kinds of flowers. With respect to the Orthoptera, I know hardly anything

about the relative number of the sexes: Korte (88. 'Die Strich, Zug oder Wanderheuschrecke,' 1828, p. 20.),

however, says that out of 500 locusts which he examined, the males were to the females as five to six. With

the Neuroptera, Mr. Walsh states that in many, but by no means in all the species of the Odonatous group,

there is a great overplus of males: in the genus Hetaerina, also, the males are generally at least four times as

numerous as the females. In certain species in the genus Gomphus the males are equally in excess, whilst in

two other species, the females are twice or thrice as numerous as the males. In some European species of

Psocus thousands of females may be collected without a single male, whilst with other species of the same

genus both sexes are common. (89. 'Observations on N. American Neuroptera,' by H. Hagen and B.D. Walsh,

'Proceedings, Ent. Soc. Philadelphia,' Oct. 1863, pp. 168, 223, 239.) In England, Mr. MacLachlan has

captured hundreds of the female Apatania muliebris, but has never seen the male; and of Boreus hyemalis

only four or five males have been seen here. (90. 'Proceedings, Ent. Soc. London,' Feb. 17, 1868.) With most

of these species (excepting the Tenthredinae) there is at present no evidence that the females are subject to

parthenogenesis; and thus we see how ignorant we are of the causes of the apparent discrepancy in the

In the other classes of the Articulata I have been able to collect still less information. With spiders, Mr.

Blackwall, who has carefully attended to this class during many years, writes to me that the males from their

more erratic habits are more commonly seen, and therefore appear more numerous. This is actually the case

with a few species; but he mentions several species in six genera, in which the females appear to be much

more numerous than the males. (91. Another great authority with respect to this class, Prof. Thorell of Upsala

('On European Spiders,' 186970, part i. p. 205), speaks as if female spiders were generally commoner than

the males.) The small size of the males in comparison with the females (a peculiarity which is sometimes

carried to an extreme degree), and their widely different appearance, may account in some instances for their

rarity in collections. (92. See, on this subject, Mr. O.P. Cambridge, as quoted in 'Quarterly Journal of

Some of the lower Crustaceans are able to propagate their kind sexually, and this will account for the extreme

rarity of the males; thus von Siebold (93. 'Beitrage zur Parthenogenesis,' p. 174.) carefully examined no less

than 13,000 specimens of Apus from twentyone localities, and amongst these he found only 319 males.

With some other forms (as Tanais and Cypris), as Fritz Muller informs me, there is reason to believe that the

males are much shorterlived than the females; and this would explain their scarcity, supposing the two sexes

to be at first equal in number. On the other hand, Muller has invariably taken far more males than females of

the Diastylidae and of Cypridina on the shores of Brazil: thus with a species in the latter genus, 63 specimens

caught the same day included 57 males; but he suggests that this preponderance may be due to some

unknown difference in the habits of the two sexes. With one of the higher Brazilian crabs, namely a

Gelasimus, Fritz Muller found the males to be more numerous than the females. According to the large

experience of Mr. C. Spence Bate, the reverse seems to be the case with six common British crabs, the names

There is reason to suspect that in some cases man has by selection indirectly influenced his own

sexproducing powers. Certain women tend to produce during their whole lives more children of one sex

than of the other: and the same holds good of many animals, for instance, cows and horses; thus Mr. Wright

of Yeldersley House informs me that one of his Arab mares, though put seven times to different horses,

produced seven fillies. Though I have very little evidence on this head, analogy would lead to the belief, that

the tendency to produce either sex would be inherited like almost every other peculiarity, for instance, that of

producing twins; and concerning the above tendency a good authority, Mr. J. Downing, has communicated to

me facts which seem to prove that this does occur in certain families of shorthorn cattle. Col. Marshall (94.

'The Todas,' 1873, pp. 100, 111, 194, 196.) has recently found on careful examination that the Todas, a

hilltribe of India, consist of 112 males and 84 females of all agesthat is in a ratio of 133.3 males to 100

females. The Todas, who are polyandrous in their marriages, during former times invariably practised female

infanticide; but this practice has now been discontinued for a considerable period. Of the children born within

late years, the males are more numerous than the females, in the proportion of 124 to 100. Colonel Marshall

accounts for this fact in the following ingenious manner. "Let us for the purpose of illustration take three

families as representing an average of the entire tribe; say that one mother gives birth to six daughters and no

sons; a second mother has six sons only, whilst the third mother has three sons and three daughters. The first

mother, following the tribal custom, destroys four daughters and preserves two. The second retains her six

sons. The third kills two daughters and keeps one, as also her three sons. We have then from the three

families, nine sons and three daughters, with which to continue the breed. But whilst the males belong to

families in which the tendency to produce sons is great, the females are of those of a converse inclination.

Thus the bias strengthens with each generation, until, as we find, families grow to have habitually more sons

That this result would follow from the above form of infanticide seems almost certain; that is if we assume

that a sexproducing tendency is inherited. But as the above numbers are so extremely scanty, I have

searched for additional evidence, but cannot decide whether what I have found is trustworthy; nevertheless

the facts are, perhaps, worth giving. The Maories of New Zealand have long practised infanticide; and Mr.

Fenton (95. 'Aboriginal Inhabitants of New Zealand: Government Report,' 1859, p. 36.) states that he "has

met with instances of women who have destroyed four, six, and even seven children, mostly females.

However, the universal testimony of those best qualified to judge, is conclusive that this custom has for many

years been almost extinct. Probably the year 1835 may be named as the period of its ceasing to exist." Now

amongst the New Zealanders, as with the Todas, male births are considerably in excess. Mr. Fenton remarks

(p. 30), "One fact is certain, although the exact period of the commencement of this singular condition of the

disproportion of the sexes cannot be demonstratively fixed, it is quite clear that this course of decrease was in

full operation during the years 1830 to 1844, when the nonadult population of 1844 was being produced,

and has continued with great energy up to the present time." The following statements are taken from Mr.

Fenton (p. 26), but as the numbers are not large, and as the census was not accurate, uniform results cannot be

expected. It should be borne in mind in this and the following cases, that the normal state of every population

is an excess of women, at least in all civilised countries, chiefly owing to the greater mortality of the male sex

during youth, and partly to accidents of all kinds later in life. In 1858, the native population of New Zealand

was estimated as consisting of 31,667 males and 24,303 females of all ages, that is in the ratio of 130.3 males

to 100 females. But during this same year, and in certain limited districts, the numbers were ascertained with

much care, and the males of all ages were here 753 and the females 616; that is in the ratio of 122.2 males to

100 females. It is more important for us that during this same year of 1858, the NONADULT males within

the same district were found to be 178, and the NONADULT females 142, that is in the ratio of 125.3 to

100. It may be added that in 1844, at which period female infanticide had only lately ceased, the

NONADULT males in one district were 281, and the NON ADULT females only 194, that is in the ratio

In the Sandwich Islands, the males exceed the females in number. Infanticide was formerly practised there to

a frightful extent, but was by no means confined to female infants, as is shewn by Mr. Ellis (96. 'Narrative of

a Tour through Hawaii,' 1826, p. 298.), and as I have been informed by Bishop Staley and the Rev. Mr. Coan.

Nevertheless, another apparently trustworthy writer, Mr. Jarves (97. 'History of the Sandwich Islands,' 1843,

p. 93.), whose observations apply to the whole archipelago, remarks:"Numbers of women are to be found,

who confess to the murder of from three to six or eight children," and he adds, "females from being

considered less useful than males were more often destroyed." From what is known to occur in other parts of

the world, this statement is probable; but must be received with much caution. The practice of infanticide

ceased about the year 1819, when idolatry was abolished and missionaries settled in the Islands. A careful

census in 1839 of the adult and taxable men and women in the island of Kauai and in one district of Oahu

(Jarves, p. 404), gives 4723 males and 3776 females; that is in the ratio of 125.08 to 100. At the same time

the number of males under fourteen years in Kauai and under eighteen in Oahu was 1797, and of females of

In a census of all the islands in 1850 (98. This is given in the Rev. H.T. Cheever's 'Life in the Sandwich

Islands,' 1851, p. 277.), the males of all ages amount to 36,272, and the females to 33,128, or as 109.49 to

100. The males under seventeen years amounted to 10,773, and the females under the same age to 9593, or as

112.3 to 100. From the census of 1872, the proportion of males of all ages (including halfcastes) to females,

is as 125.36 to 100. It must be borne in mind that all these returns for the Sandwich Islands give the

proportion of living males to living females, and not of the births; and judging from all civilised countries the

proportion of males would have been considerably higher if the numbers had referred to births. (99. Dr.

Coulter, in describing ('Journal R. Geograph. Soc.' vol. v. 1835, p. 67) the state of California about the year

1830, says that the natives, reclaimed by the Spanish missionaries, have nearly all perished, or are perishing,

although well treated, not driven from their native land, and kept from the use of spirits. He attributes this, in

great part, to the undoubted fact that the men greatly exceed the women in number; but he does not know

whether this is due to a failure of female offspring, or to more females dying during early youth. The latter

alternative, according to all analogy, is very improbable. He adds that "infanticide, properly so called, is not

common, though very frequent recourse is had to abortion." If Dr. Coulter is correct about infanticide, this

case cannot be advanced in support of Colonel Marshall's view. From the rapid decrease of the reclaimed

natives, we may suspect that, as in the cases lately given, their fertility has been diminished from changed

I had hoped to gain some light on this subject from the breeding of dogs; inasmuch as in most breeds, with

the exception, perhaps, of greyhounds, many more female puppies are destroyed than males, just as with the

Toda infants. Mr. Cupples assures me that this is usual with Scotch deer hounds. Unfortunately, I know

nothing of the proportion of the sexes in any breed, excepting greyhounds, and there the male births are to the

females as 110.1 to 100. Now from enquiries made from many breeders, it seems that the females are in some

respects more esteemed, though otherwise troublesome; and it does not appear that the female puppies of the

best bred dogs are systematically destroyed more than the males, though this does sometimes take place to a

limited extent. Therefore I am unable to decide whether we can, on the above principles, account for the

preponderance of male births in greyhounds. On the other hand, we have seen that with horses, cattle, and

sheep, which are too valuable for the young of either sex to be destroyed, if there is any difference, the

From the several foregoing cases we have some reason to believe that infanticide practised in the manner

above explained, tends to make a male producing race; but I am far from supposing that this practice in the

case of man, or some analogous process with other species, has been the sole determining cause of an excess

of males. There may be some unknown law leading to this result in decreasing races, which have already

become somewhat infertile. Besides the several causes previously alluded to, the greater facility of parturition

amongst savages, and the less consequent injury to their male infants, would tend to increase the proportion

of liveborn males to females. There does not, however, seem to be any necessary connection between

savage life and a marked excess of males; that is if we may judge by the character of the scanty offspring of

the lately existing Tasmanians and of the crossed offspring of the Tahitians now inhabiting Norfolk Island.

As the males and females of many animals differ somewhat in habits and are exposed in different degrees to

danger, it is probable that in many cases, more of one sex than of the other are habitually destroyed. But as

far as I can trace out the complication of causes, an indiscriminate though large destruction of either sex

would not tend to modify the sexproducing power of the species. With strictly social animals, such as bees

or ants, which produce a vast number of sterile and fertile females in comparison with the males, and to

whom this preponderance is of paramount importance, we can see that those communities would flourish best

which contained females having a strong inherited tendency to produce more and more females; and in such

cases an unequal sexproducing tendency would be ultimately gained through natural selection. With animals

living in herds or troops, in which the males come to the front and defend the herd, as with the bisons of

North America and certain baboons, it is conceivable that a male producing tendency might be gained by

natural selection; for the individuals of the better defended herds would leave more numerous descendants. In

the case of mankind the advantage arising from having a preponderance of men in the tribe is supposed to be

In no case, as far as we can see, would an inherited tendency to produce both sexes in equal numbers or to

produce one sex in excess, be a direct advantage or disadvantage to certain individuals more than to others;

for instance, an individual with a tendency to produce more males than females would not succeed better in

the battle for life than an individual with an opposite tendency; and therefore a tendency of this kind could

not be gained through natural selection. Nevertheless, there are certain animals (for instance, fishes and

cirripedes) in which two or more males appear to be necessary for the fertilisation of the female; and the

males accordingly largely preponderate, but it is by no means obvious how this maleproducing tendency

could have been acquired. I formerly thought that when a tendency to produce the two sexes in equal

numbers was advantageous to the species, it would follow from natural selection, but I now see that the

whole problem is so intricate that it is safer to leave its solution for the future.

These characters absent in the lowest classesBrilliant coloursMollusca AnnelidsCrustacea,

secondary sexual characters strongly developed; dimorphism; colour; characters not acquired before

With animals belonging to the lower classes, the two sexes are not rarely united in the same individual, and

therefore secondary sexual characters cannot be developed. In many cases where the sexes are separate, both

are permanently attached to some support, and the one cannot search or struggle for the other. Moreover it is

almost certain that these animals have too imperfect senses and much too low mental powers to appreciate

Hence in these classes or subkingdoms, such as the Protozoa, Coelenterata, Echinodermata, Scolecida,

secondary sexual characters, of the kind which we have to consider, do not occur: and this fact agrees with

the belief that such characters in the higher classes have been acquired through sexual selection, which

depends on the will, desire, and choice of either sex. Nevertheless some few apparent exceptions occur; thus,

as I hear from Dr. Baird, the males of certain Entozoa, or internal parasitic worms, differ slightly in colour

from the females; but we have no reason to suppose that such differences have been augmented through

sexual selection. Contrivances by which the male holds the female, and which are indispensable for the

propagation of the species, are independent of sexual selection, and have been acquired through ordinary

Many of the lower animals, whether hermaphrodites or with separate sexes, are ornamented with the most

brilliant tints, or are shaded and striped in an elegant manner; for instance, many corals and seaanemones

(Actiniae), some jellyfish (Medusae, Porpita, etc.), some Planariae, many starfishes, Echini, Ascidians,

etc.; but we may conclude from the reasons already indicated, namely, the union of the two sexes in some of

these animals, the permanently affixed condition of others, and the low mental powers of all, that such

colours do not serve as a sexual attraction, and have not been acquired through sexual selection. It should be

borne in mind that in no case have we sufficient evidence that colours have been thus acquired, except where

one sex is much more brilliantly or conspicuously coloured than the other, and where there is no difference in

habits between the sexes sufficient to account for their different colours. But the evidence is rendered as

complete as it can ever be, only when the more ornamented individuals, almost always the males, voluntarily

display their attractions before the other sex; for we cannot believe that such display is useless, and if it be

advantageous, sexual selection will almost inevitably follow. We may, however, extend this conclusion to

both sexes, when coloured alike, if their colours are plainly analogous to those of one sex alone in certain

How, then, are we to account for the beautiful or even gorgeous colours of many animals in the lowest

classes? It appears doubtful whether such colours often serve as a protection; but that we may easily err on

this head, will be admitted by every one who reads Mr. Wallace's excellent essay on this subject. It would

not, for instance, at first occur to any one that the transparency of the Medusae, or jellyfish, is of the highest

service to them as a protection; but when we are reminded by Haeckel that not only the Medusae, but many

floating Mollusca, crustaceans, and even small oceanic fishes partake of this same glasslike appearance,

often accompanied by prismatic colours, we can hardly doubt that they thus escape the notice of pelagic birds

and other enemies. M. Giard is also convinced (1. 'Archives de Zoolog. Exper.' Oct. 1872, p. 563.) that the

bright tints of certain sponges and ascidians serve as a protection. Conspicuous colours are likewise

beneficial to many animals as a warning to their wouldbe devourers that they are distasteful, or that they

possess some special means of defence; but this subject will be discussed more conveniently hereafter.

We can, in our ignorance of most of the lowest animals, only say that their bright tints result either from the

chemical nature or the minute structure of their tissues, independently of any benefit thus derived. Hardly any

colour is finer than that of arterial blood; but there is no reason to suppose that the colour of the blood is in

itself any advantage; and though it adds to the beauty of the maiden's cheek, no one will pretend that it has

been acquired for this purpose. So again with many animals, especially the lower ones, the bile is richly

coloured; thus, as I am informed by Mr. Hancock, the extreme beauty of the Eolidae (naked seaslugs) is

chiefly due to the biliary glands being seen through the translucent integumentsthis beauty being probably

of no service to these animals. The tints of the decaying leaves in an American forest are described by every

one as gorgeous; yet no one supposes that these tints are of the least advantage to the trees. Bearing in mind

how many substances closely analogous to natural organic compounds have been recently formed by

chemists, and which exhibit the most splendid colours, it would have been a strange fact if substances

similarly coloured had not often originated, independently of any useful end thus gained, in the complex

Throughout this great division of the animal kingdom, as far as I can discover, secondary sexual characters,

such as we are here considering, never occur. Nor could they be expected in the three lowest classes, namely,

in the Ascidians, Polyzoa, and Brachiopods (constituting the Molluscoida of some authors), for most of these

animals are permanently affixed to a support or have their sexes united in the same individual. In the

Lamellibranchiata, or bivalve shells, hermaphroditism is not rare. In the next higher class of the Gasteropoda,

or univalve shells, the sexes are either united or separate. But in the latter case the males never possess

special organs for finding, securing, or charming the females, or for fighting with other males. As I am

informed by Mr. Gwyn Jeffreys, the sole external difference between the sexes consists in the shell

sometimes differing a little in form; for instance, the shell of the male periwinkle (Littorina littorea) is

narrower and has a more elongated spire than that of the female. But differences of this nature, it may be

presumed, are directly connected with the act of reproduction, or with the development of the ova.

The Gasteropoda, though capable of locomotion and furnished with imperfect eyes, do not appear to be

endowed with sufficient mental powers for the members of the same sex to struggle together in rivalry, and

thus to acquire secondary sexual characters. Nevertheless with the pulmoniferous gasteropods, or landsnails,

the pairing is preceded by courtship; for these animals, though hermaphrodites, are compelled by their

structure to pair together. Agassiz remarks, "Quiconque a eu l'occasion d'observer les amours des limacons,

ne saurait mettre en doute la seduction deployee dans les mouvements et les allures qui preparent et

accomplissent le double embrassement de ces hermaphrodites." (2. 'De l'Espece et de la Class.' etc., 1869, p.

106.) These animals appear also susceptible of some degree of permanent attachment: an accurate observer,

Mr. Lonsdale, informs me that he placed a pair of landsnails, (Helix pomatia), one of which was weakly,

into a small and illprovided garden. After a short time the strong and healthy individual disappeared, and

was traced by its track of slime over a wall into an adjoining wellstocked garden. Mr. Lonsdale concluded

that it had deserted its sickly mate; but after an absence of twentyfour hours it returned, and apparently

communicated the result of its successful exploration, for both then started along the same track and

Even in the highest class of the Mollusca, the Cephalopoda or cuttle fishes, in which the sexes are separate,

secondary sexual characters of the present kind do not, as far as I can discover, occur. This is a surprising

circumstance, as these animals possess highlydeveloped senseorgans and have considerable mental

powers, as will be admitted by every one who has watched their artful endeavours to escape from an enemy.

(3. See, for instance, the account which I have given in my 'Journal of Researches,' 1845, p. 7.) Certain

Cephalopoda, however, are characterised by one extraordinary sexual character, namely that the male

element collects within one of the arms or tentacles, which is then cast off, and clinging by its suckingdiscs

to the female, lives for a time an independent life. So completely does the castoff arm resemble a separate

animal, that it was described by Cuvier as a parasitic worm under the name of Hectocotyle. But this

marvellous structure may be classed as a primary rather than as a secondary sexual character.

Although with the Mollusca sexual selection does not seem to have come into play; yet many univalve and

bivalve shells, such as volutes, cones, scallops, etc., are beautifully coloured and shaped. The colours do not

appear in most cases to be of any use as a protection; they are probably the direct result, as in the lowest

classes, of the nature of the tissues; the patterns and the sculpture of the shell depending on its manner of

growth. The amount of light seems to be influential to a certain extent; for although, as repeatedly stated by

Mr. Gwyn Jeffreys, the shells of some species living at a profound depth are brightly coloured, yet we

generally see the lower surfaces, as well as the parts covered by the mantle, less highlycoloured than the

upper and exposed surfaces. (4. I have given ('Geological Observations on Volcanic Islands,' 1844, p. 53) a

curious instance of the influence of light on the colours of a frondescent incrustation, deposited by the surf on

the coastrocks of Ascension and formed by the solution of triturated seashells.) In some cases, as with

shells living amongst corals or brightlytinted seaweeds, the bright colours may serve as a protection. (5. Dr.

Morse has lately discussed this subject in his paper on the 'Adaptive Coloration of Mollusca,' 'Proc. Boston

Soc. of Nat. Hist.' vol. xiv. April 1871.) But that many of the nudibranch Mollusca, or seaslugs, are as

beautifully coloured as any shells, may be seen in Messrs. Alder and Hancock's magnificent work; and from

information kindly given me by Mr. Hancock, it seems extremely doubtful whether these colours usually

serve as a protection. With some species this may be the case, as with one kind which lives on the green

leaves of algae, and is itself brightgreen. But many brightlycoloured, white, or otherwise conspicuous

species, do not seek concealment; whilst again some equally conspicuous species, as well as other

dullcoloured kinds live under stones and in dark recesses. So that with these nudibranch molluscs, colour

apparently does not stand in any close relation to the nature of the places which they inhabit.

These naked seaslugs are hermaphrodites, yet they pair together, as do landsnails, many of which have

extremely pretty shells. It is conceivable that two hermaphrodites, attracted by each other's greater beauty,

might unite and leave offspring which would inherit their parents' greater beauty. But with such

lowlyorganised creatures this is extremely improbable. Nor is it at all obvious how the offspring from the

more beautiful pairs of hermaphrodites would have any advantage over the offspring of the less beautiful, so

as to increase in number, unless indeed vigour and beauty generally coincided. We have not here the case of a

number of males becoming mature before the females, with the more beautiful males selected by the more

vigorous females. If, indeed, brilliant colours were beneficial to a hermaphrodite animal in relation to its

general habits of life, the more brightlytinted individuals would succeed best and would increase in number;

In this class, although the sexes, when separate, sometimes differ from each other in characters of such

importance that they have been placed under distinct genera or even families, yet the differences do not seem

of the kind which can be safely attributed to sexual selection. These animals are often beautifully coloured,

but as the sexes do not differ in this respect, we are but little concerned with them. Even the Nemertians,

though so lowly organised, "vie in beauty and variety of colouring with any other group in the invertebrate

series"; yet Dr. McIntosh (6. See his beautiful monograph on 'British Annelids,' part i. 1873, p. 3.) cannot

discover that these colours are of any service. The sedentary annelids become dullercoloured, according to

M. Quatrefages (7. See M. Perrier: 'L'Origine de l'Homme d'apres Darwin,' 'Revue Scientifique', Feb. 1873, p.

866.), after the period of reproduction; and this I presume may be attributed to their less vigorous condition at

that time. All these worm like animals apparently stand too low in the scale for the individuals of either sex

to exert any choice in selecting a partner, or for the individuals of the same sex to struggle together in rivalry.

In this great class we first meet with undoubted secondary sexual characters, often developed in a remarkable

manner. Unfortunately the habits of crustaceans are very imperfectly known, and we cannot explain the uses

of many structures peculiar to one sex. With the lower parasitic species the males are of small size, and they

alone are furnished with perfect swimminglegs, antennae and senseorgans; the females being destitute of

these organs, with their bodies often consisting of a mere distorted mass. But these extraordinary differences

between the two sexes are no doubt related to their widely different habits of life, and consequently do not

concern us. In various crustaceans, belonging to distinct families, the anterior antennae are furnished with

peculiar threadlike bodies, which are believed to act as smellingorgans, and these are much more

numerous in the males than in the females. As the males, without any unusual development of their olfactory

organs, would almost certainly be able sooner or later to find the females, the increased number of the

smellingthreads has probably been acquired through sexual selection, by the better provided males having

been the more successful in finding partners and in producing offspring. Fritz Muller has described a

remarkable dimorphic species of Tanais, in which the male is represented by two distinct forms, which never

graduate into each other. In the one form the male is furnished with more numerous smellingthreads, and in

the other form with more powerful and more elongated chelae or pincers, which serve to hold the female.

Fritz Muller suggests that these differences between the two male forms of the same species may have

originated in certain individuals having varied in the number of the smellingthreads, whilst other individuals

varied in the shape and size of their chelae; so that of the former, those which were best able to find the

female, and of the latter, those which were best able to hold her, have left the greatest number of progeny to

inherit their respective advantages. (8. 'Facts and Arguments for Darwin,' English translat., 1869, p. 20. See

the previous discussion on the olfactory threads. Sars has described a somewhat analogous case (as quoted in

[Fig.4. Labidocera Darwinii (from Lubbock). Labelled are: a. Part of right anterior antenna of male, forming

a prehensile organ. b. Posterior pair of thoracic legs of male. c. Ditto of female.]

In some of the lower crustaceans, the right anterior antenna of the male differs greatly in structure from the

left, the latter resembling in its simple tapering joints the antennae of the female. In the male the modified

antenna is either swollen in the middle or angularly bent, or converted (Fig. 4) into an elegant, and sometimes

wonderfully complex, prehensile organ. (9. See Sir J. Lubbock in 'Annals and Mag. of Nat. Hist.' vol. xi.

1853, pl. i. and x.; and vol. xii. (1853), pl. vii. See also Lubbock in 'Transactions, Entomological Society,'

vol. iv. new series, 18561858, p. 8. With respect to the zigzagged antennae mentioned below, see Fritz

Muller, 'Facts and Arguments for Darwin,' 1869, p. 40, foot note.) It serves, as I hear from Sir J. Lubbock,

to hold the female, and for this same purpose one of the two posterior legs (b) on the same side of the body is

converted into a forceps. In another family the inferior or posterior antennae are "curiously zigzagged" in the

[Fig. 5. Anterior part of body of Callianassa (from MilneEdwards), showing the unequal and

differentlyconstructed right and lefthand chelae of the male. N.B.The artist by mistake has reversed the

In the higher crustaceans the anterior legs are developed into chelae or pincers; and these are generally larger

in the male than in the female,so much so that the market value of the male edible crab (Cancer pagurus),

according to Mr. C. Spence Bate, is five times as great as that of the female. In many species the chelae are of

unequal size on the opposite side of the body, the righthand one being, as I am informed by Mr. Bate,

generally, though not invariably, the largest. This inequality is also often much greater in the male than in the

female. The two chelae of the male often differ in structure (Figs. 5, 6, and 7), the smaller one resembling that

of the female. What advantage is gained by their inequality in size on the opposite sides of the body, and by

the inequality being much greater in the male than in the female; and why, when they are of equal size, both

are often much larger in the male than in the female, is not known. As I hear from Mr. Bate, the chelae are

sometimes of such length and size that they cannot possibly be used for carrying food to the mouth. In the

males of certain freshwater prawns (Palaemon) the right leg is actually longer than the whole body. (10. See

a paper by Mr. C. Spence Bate, with figures, in 'Proceedings, Zoological Society,' 1868, p. 363; and on the

nomenclature of the genus, ibid. p. 585. I am greatly indebted to Mr. Spence Bate for nearly all the above

statements with respect to the chelae of the higher crustaceans.) The great size of the one leg with its chelae

may aid the male in fighting with his rivals; but this will not account for their inequality in the female on the

opposite sides of the body. In Gelasimus, according to a statement quoted by Milne Edwards (11. 'Hist. Nat.

des Crust.' tom. ii. 1837, p. 50.), the male and the female live in the same burrow, and this shews that they

pair; the male closes the mouth of the burrow with one of its chelae, which is enormously developed; so that

here it indirectly serves as a means of defence. Their main use, however, is probably to seize and to secure

the female, and this in some instances, as with Gammarus, is known to be the case. The male of the hermit or

soldier crab (Pagurus) for weeks together, carries about the shell inhabited by the female. (12. Mr. C. Spence

Bate, 'British Association, Fourth Report on the Fauna of S. Devon.') The sexes, however, of the common

shorecrab (Carcinus maenas), as Mr. Bate informs me, unite directly after the female has moulted her hard

shell, when she is so soft that she would be injured if seized by the strong pincers of the male; but as she is

caught and carried about by the male before moulting, she could then be seized with impunity.

[Fig.8. Orchestia Darwinii (from Fritz Muller), showing the differently constructed chelae of the two male

Fritz Muller states that certain species of Melita are distinguished from all other amphipods by the females

having "the coxal lamellae of the penultimate pair of feet produced into hooklike processes, of which the

males lay hold with the hands of the first pair." The development of these hooklike processes has probably

followed from those females which were the most securely held during the act of reproduction, having left

the largest number of offspring. Another Brazilian amphipod (see Orchestia darwinii, Fig. 8) presents a case

of dimorphism, like that of Tanais; for there are two male forms, which differ in the structure of their chelae.

(13. Fritz Muller, 'Facts and Arguments for Darwin,' 1869, pp. 2528.) As either chela would certainly

suffice to hold the female,for both are now used for this purpose,the two male forms probably

originated by some having varied in one manner and some in another; both forms having derived certain

It is not known that male crustaceans fight together for the possession of the females, but it is probably the

case; for with most animals when the male is larger than the female, he seems to owe his greater size to his

ancestors having fought with other males during many generations. In most of the orders, especially in the

highest or the Brachyura, the male is larger than the female; the parasitic genera, however, in which the sexes

follow different habits of life, and most of the Entomostraca must be excepted. The chelae of many

crustaceans are weapons well adapted for fighting. Thus when a Devilcrab (Portunus puber) was seen by a

son of Mr. Bate fighting with a Carcinus maenas, the latter was soon thrown on its back, and had every limb

torn from its body. When several males of a Brazilian Gelasimus, a species furnished with immense pincers,

were placed together in a glass vessel by Fritz Muller, they mutilated and killed one another. Mr. Bate put a

large male Carcinus maenas into a pan of water, inhabited by a female which was paired with a smaller male;

but the latter was soon dispossessed. Mr. Bate adds, "if they fought, the victory was a bloodless one, for I saw

no wounds." This same naturalist separated a male sandskipper (so common on our seashores), Gammarus

marinus, from its female, both of whom were imprisoned in the same vessel with many individuals of the

same species. The female, when thus divorced, soon joined the others. After a time the male was put again

into the same vessel; and he then, after swimming about for a time, dashed into the crowd, and without any

fighting at once took away his wife. This fact shews that in the Amphipoda, an order low in the scale, the

The mental powers of the Crustacea are probably higher than at first sight appears probable. Any one who

tries to catch one of the shorecrabs, so common on tropical coasts, will perceive how wary and alert they

are. There is a large crab (Birgus latro), found on coral islands, which makes a thick bed of the picked fibres

of the cocoanut, at the bottom of a deep burrow. It feeds on the fallen fruit of this tree by tearing off the

husk, fibre by fibre; and it always begins at that end where the three eyelike depressions are situated. It then

breaks through one of these eyes by hammering with its heavy front pincers, and turning round, extracts the

albuminous core with its narrow posterior pincers. But these actions are probably instinctive, so that they

would be performed as well by a young animal as by an old one. The following case, however, can hardly be

so considered: a trustworthy naturalist, Mr. Gardner (14. 'Travels in the Interior of Brazil,' 1846, p. 111. I

have given, in my 'Journal of Researches,' p. 463, an account of the habits of the Birgus.), whilst watching a

shorecrab (Gelasimus) making its burrow, threw some shells towards the hole. One rolled in, and three other

shells remained within a few inches of the mouth. In about five minutes the crab brought out the shell which

had fallen in, and carried it away to a distance of a foot; it then saw the three other shells lying near, and

evidently thinking that they might likewise roll in, carried them to the spot where it had laid the first. It

would, I think, be difficult to distinguish this act from one performed by man by the aid of reason.

Mr. Bate does not know of any wellmarked case of difference of colour in the two sexes of our British

crustaceans, in which respect the sexes of the higher animals so often differ. In some cases, however, the

males and females differ slightly in tint, but Mr. Bate thinks not more than may be accounted for by their

different habits of life, such as by the male wandering more about, and being thus more exposed to the light.

Dr. Power tried to distinguish by colour the sexes of the several species which inhabit the Mauritius, but

failed, except with one species of Squilla, probably S. stylifera, the male of which is described as being "of a

beautiful bluishgreen," with some of the appendages cherryred, whilst the female is clouded with brown

and grey, "with the red about her much less vivid than in the male." (15. Mr. Ch. Fraser, in 'Proc. Zoolog.

Soc.' 1869, p. 3. I am indebted to Mr. Bate for Dr. Power's statement.) In this case, we may suspect the

agency of sexual selection. From M. Bert's observations on Daphnia, when placed in a vessel illuminated by a

prism, we have reason to believe that even the lowest crustaceans can distinguish colours. With Saphirina (an

oceanic genus of Entomostraca), the males are furnished with minute shields or celllike bodies, which

exhibit beautiful changing colours; these are absent in the females, and in both sexes of one species. (16.

Claus, 'Die freilebenden Copepoden,' 1863, s. 35.) It would, however, be extremely rash to conclude that

these curious organs serve to attract the females. I am informed by Fritz Muller, that in the female of a

Brazilian species of Gelasimus, the whole body is of a nearly uniform greyishbrown. In the male the

posterior part of the cephalo thorax is pure white, with the anterior part of a rich green, shading into dark

brown; and it is remarkable that these colours are liable to change in the course of a few minutesthe white

becoming dirty grey or even black, the green "losing much of its brilliancy." It deserves especial notice that

the males do not acquire their bright colours until they become mature. They appear to be much more

numerous than the females; they differ also in the larger size of their chelae. In some species of the genus,

probably in all, the sexes pair and inhabit the same burrow. They are also, as we have seen, highly intelligent

animals. From these various considerations it seems probable that the male in this species has become gaily

It has just been stated that the male Gelasimus does not acquire his conspicuous colours until mature and

nearly ready to breed. This seems a general rule in the whole class in respect to the many remarkable

structural differences between the sexes. We shall hereafter find the same law prevailing throughout the great

subkingdom of the Vertebrata; and in all cases it is eminently distinctive of characters which have been

acquired through sexual selection. Fritz Muller (17. 'Facts and Arguments,' etc., p. 79.) gives some striking

instances of this law; thus the male sandhopper (Orchestia) does not, until nearly full grown, acquire his

large claspers, which are very differently constructed from those of the female; whilst young, his claspers

The sexes do not generally differ much in colour, but the males are often darker than the females, as may be

seen in Mr. Blackwall's magnificent work. (18. 'A History of the Spiders of Great Britain,' 186164. For the

following facts, see pp. 77, 88, 102.) In some species, however, the difference is conspicuous: thus the female

of Sparassus smaragdulus is dullish green, whilst the adult male has the abdomen of a fine yellow, with three

longitudinal stripes of rich red. In certain species of Thomisus the sexes closely resemble each other, in others

they differ much; and analogous cases occur in many other genera. It is often difficult to say which of the two

sexes departs most from the ordinary coloration of the genus to which the species belong; but Mr. Blackwall

thinks that, as a general rule, it is the male; and Canestrini (19. This author has recently published a valuable

essay on the 'Caratteri sessuali secondarii degli Arachnidi,' in the 'Atti della Soc. VenetoTrentina di Sc. Nat.

Padova,' vol. i. Fasc. 3, 1873.) remarks that in certain genera the males can be specifically distinguished with

ease, but the females with great difficulty. I am informed by Mr. Blackwall that the sexes whilst young

usually resemble each other; and both often undergo great changes in colour during their successive moults,

before arriving at maturity. In other cases the male alone appears to change colour. Thus the male of the

above brightcoloured Sparassus at first resembles the female, and acquires his peculiar tints only when

nearly adult. Spiders are possessed of acute senses, and exhibit much intelligence; as is well known, the

females often shew the strongest affection for their eggs, which they carry about enveloped in a silken web.

The males search eagerly for the females, and have been seen by Canestrini and others to fight for possession

of them. This same author says that the union of the two sexes has been observed in about twenty species;

and he asserts positively that the female rejects some of the males who court her, threatens them with open

mandibles, and at last after long hesitation accepts the chosen one. From these several considerations, we may

admit with some confidence that the wellmarked differences in colour between the sexes of certain species

are the results of sexual selection; though we have not here the best kind of evidence, the display by the

male of his ornaments. From the extreme variability of colour in the male of some species, for instance of

Theridion lineatum, it would appear that these sexual characters of the males have not as yet become well

fixed. Canestrini draws the same conclusion from the fact that the males of certain species present two forms,

differing from each other in the size and length of their jaws; and this reminds us of the above cases of

The male is generally much smaller than the female, sometimes to an extraordinary degree (20. Aug. Vinson

('Araneides des Iles de la Reunion,' pl. vi. figs. 1 and 2) gives a good instance of the small size of the male, in

Epeira nigra. In this species, as I may add, the male is testaceous and the female black with legs banded with

red. Other even more striking cases of inequality in size between the sexes have been recorded ('Quarterly

Journal of Science,' July 1868, p. 429); but I have not seen the original accounts.), and he is forced to be

extremely cautious in making his advances, as the female often carries her coyness to a dangerous pitch. De

Geer saw a male that "in the midst of his preparatory caresses was seized by the object of his attentions,

enveloped by her in a web and then devoured, a sight which, as he adds, filled him with horror and

indignation." (21. Kirby and Spence, 'Introduction to Entomology,' vol. i. 1818, p. 280.) The Rev. O.P.

Cambridge (22. 'Proceedings, Zoological Society,' 1871, p. 621.) accounts in the following manner for the

extreme smallness of the male in the genus Nephila. "M. Vinson gives a graphic account of the agile way in

which the diminutive male escapes from the ferocity of the female, by gliding about and playing hide and

seek over her body and along her gigantic limbs: in such a pursuit it is evident that the chances of escape

would be in favour of the smallest males, while the larger ones would fall early victims; thus gradually a

diminutive race of males would be selected, until at last they would dwindle to the smallest possible size

compatible with the exercise of their generative functions, in fact, probably to the size we now see them,

i.e., so small as to be a sort of parasite upon the female, and either beneath her notice, or too agile and too

Westring has made the interesting discovery that the males of several species of Theridion (23. Theridion

(Asagena, Sund.) serratipes, 4 punctatum et guttatum; see Westring, in Kroyer, 'Naturhist. Tidskrift,' vol. iv.

18421843, p. 349; and vol. ii. 18461849, p. 342. See, also, for other species, 'Araneae Suecicae,' p. 184.)

have the power of making a stridulating sound, whilst the females are mute. The apparatus consists of a

serrated ridge at the base of the abdomen, against which the hard hinder part of the thorax is rubbed; and of

this structure not a trace can be detected in the females. It deserves notice that several writers, including the

wellknown arachnologist Walckenaer, have declared that spiders are attracted by music. (24. Dr. H.H. van

Zouteveen, in his Dutch translation of this work (vol. i. p. 444), has collected several cases.) From the

analogy of the Orthoptera and Homoptera, to be described in the next chapter, we may feel almost sure that

the stridulation serves, as Westring also believes, to call or to excite the female; and this is the first case

known to me in the ascending scale of the animal kingdom of sounds emitted for this purpose. (25.

Hilgendorf, however, has lately called attention to an analogous structure in some of the higher crustaceans,

In neither of the two orders in this class, the millipedes and centipedes, can I find any wellmarked instances

of such sexual differences as more particularly concern us. In Glomeris limbata, however, and perhaps in

some few other species, the males differ slightly in colour from the females; but this Glomeris is a highly

variable species. In the males of the Diplopoda, the legs belonging either to one of the anterior or of the

posterior segments of the body are modified into prehensile hooks which serve to secure the female. In some

species of Iulus the tarsi of the male are furnished with membranous suckers for the same purpose. As we

shall see when we treat of Insects, it is a much more unusual circumstance, that it is the female in Lithobius,

which is furnished with prehensile appendages at the extremity of her body for holding the male. (26.

Walckenaer et P. Gervais, 'Hist. Nat. des Insectes: Apteres,' tom. iv. 1847, pp. 17, 19, 68.)

Diversified structures possessed by the males for seizing the females Differences between the sexes, of

aloneOrthoptera, musical instruments of the males, much diversified in structure; pugnacity;

coloursNeuroptera, sexual differences in colourHymenoptera, pugnacity and odoursColeoptera,

colours; furnished with great horns, apparently as an ornament; battles, stridulating organs generally common

In the immense class of insects the sexes sometimes differ in their locomotiveorgans, and often in their

senseorgans, as in the pectinated and beautifully plumose antennae of the males of many species. In

Chloeon, one of the Ephemerae, the male has great pillared eyes, of which the female is entirely destitute. (1.

Sir J. Lubbock, 'Transact. Linnean Soc.' vol. xxv, 1866, p. 484. With respect to the Mutillidae see Westwood,

'Modern Class. of Insects,' vol. ii. p. 213.) The ocelli are absent in the females of certain insects, as in the

Mutillidae; and here the females are likewise wingless. But we are chiefly concerned with structures by

which one male is enabled to conquer another, either in battle or courtship, through his strength, pugnacity,

ornaments, or music. The innumerable contrivances, therefore, by which the male is able to seize the female,

may be briefly passed over. Besides the complex structures at the apex of the abdomen, which ought perhaps

to be ranked as primary organs (2. These organs in the male often differ in closelyallied species, and afford

excellent specific characters. But their importance, from a functional point of view, as Mr. R. MacLachlan

has remarked to me, has probably been overrated. It has been suggested, that slight differences in these

organs would suffice to prevent the intercrossing of wellmarked varieties or incipient species, and would

thus aid in their development. That this can hardly be the case, we may infer from the many recorded cases

(see, for instance, Bronn, 'Geschichte der Natur,' B. ii. 1843, s. 164; and Westwood, 'Transact. Ent. Soc.' vol.

iii. 1842, p. 195) of distinct species having been observed in union. Mr. MacLachlan informs me (vide 'Stett.

Ent. Zeitung,' 1867, s. 155) that when several species of Phryganidae, which present stronglypronounced

differences of this kind, were confined together by Dr. Aug. Meyer, THEY COUPLED, and one pair

produced fertile ova.), "it is astonishing," as Mr. B.D. Walsh (3. 'The Practical Entomologist,' Philadelphia,

vol. ii. May 1867, p 88.) has remarked, "how many different organs are worked in by nature for the

seemingly insignificant object of enabling the male to grasp the female firmly." The mandibles or jaws are

sometimes used for this purpose; thus the male Corydalis cornutus (a neuropterous insect in some degree

allied to the Dragon flies, etc.) has immense curved jaws, many times longer than those of the female; and

they are smooth instead of being toothed, so that he is thus enabled to seize her without injury. (4. Mr. Walsh,

ibid. p. 107.) One of the stagbeetles of North America (Lucanus elaphus) uses his jaws, which are much

larger than those of the female, for the same purpose, but probably likewise for fighting. In one of the sand

wasps (Ammophila) the jaws in the two sexes are closely alike, but are used for widely different purposes:

the males, as Professor Westwood observes, "are exceedingly ardent, seizing their partners round the neck

with their sickleshaped jaws" (5. 'Modern Classification of Insects,' vol. ii. 1840, pp. 205, 206. Mr. Walsh,

who called my attention to the double use of the jaws, says that he has repeatedly observed this fact.); whilst

The tarsi of the frontlegs are dilated in many male beetles, or are furnished with broad cushions of hairs; and

in many genera of waterbeetles they are armed with a round flat sucker, so that the male may adhere to the

slippery body of the female. It is a much more unusual circumstance that the females of some waterbeetles

(Dytiscus) have their elytra deeply grooved, and in Acilius sulcatus thickly set with hairs, as an aid to the

male. The females of some other waterbeetles (Hydroporus) have their elytra punctured for the same

purpose. (6. We have here a curious and inexplicable case of dimorphism, for some of the females of four

European species of Dytiscus, and of certain species of Hydroporus, have their elytra smooth; and no

intermediate gradations between the sulcated or punctured, and the quite smooth elytra have been observed.

See Dr. H. Schaum, as quoted in the 'Zoologist,' vols. v.vi. 184748, p. 1896. Also Kirby and Spence,

'Introduction to Entomology,' vol. iii. 1826, p. 305.) In the male of Crabro cribrarius (Fig. 9), it is the tibia

which is dilated into a broad horny plate, with minute membraneous dots, giving to it a singular appearance

like that of a riddle. (7. Westwood, 'Modern Class.' vol. ii. p. 193. The following statement about Penthe, and

others in inverted commas, are taken from Mr. Walsh, 'Practical Entomologist,' Philadelphia, vol. iii. p. 88.)

In the male of Penthe (a genus of beetles) a few of the middle joints of the antennae are dilated and furnished

on the inferior surface with cushions of hair, exactly like those on the tarsi of the Carabidae, "and obviously

for the same end." In male dragonflies, "the appendages at the tip of the tail are modified in an almost

infinite variety of curious patterns to enable them to embrace the neck of the female." Lastly, in the males of

many insects, the legs are furnished with peculiar spines, knobs or spurs; or the whole leg is bowed or

thickened, but this is by no means invariably a sexual character; or one pair, or all three pairs are elongated,

sometimes to an extravagant length. (8. Kirby and Spence, 'Introduct.' etc., vol. iii. pp. 332336.)

[Fig. 10. Taphroderes distortus (much enlarged). Upper figure, male; lower figure, female.]

The sexes of many species in all the orders present differences, of which the meaning is not understood. One

curious case is that of a beetle (Fig. 10), the male of which has left mandible much enlarged; so that the

mouth is greatly distorted. In another Carabidous beetle, Eurygnathus (9. 'Insecta Maderensia,' 1854, page

20.), we have the case, unique as far as known to Mr. Wollaston, of the head of the female being much

broader and larger, though in a variable degree, than that of the male. Any number of such cases could be

given. They abound in the Lepidoptera: one of the most extraordinary is that certain male butterflies have

their forelegs more or less atrophied, with the tibiae and tarsi reduced to mere rudimentary knobs. The

wings, also, in the two sexes often differ in neuration (10. E. Doubleday, 'Annals and Mag. of Nat. Hist.' vol.

i. 1848, p. 379. I may add that the wings in certain Hymenoptera (see Shuckard, 'Fossorial Hymenoptera,'

1837, pp. 3943) differ in neuration according to sex.), and sometimes considerably in outline, as in the

Aricoris epitus, which was shewn to me in the British Museum by Mr. A. Butler. The males of certain South

American butterflies have tufts of hair on the margins of the wings, and horny excrescences on the discs of

the posterior pair. (11. H.W. Bates, in 'Journal of Proc. Linn. Soc.' vol. vi. 1862, p. 74. Mr. Wonfor's

observations are quoted in 'Popular Science Review,' 1868, p. 343.) In several British butterflies, as shewn by

The use of the bright light of the female glowworm has been subject to much discussion. The male is feebly

luminous, as are the larvae and even the eggs. It has been supposed by some authors that the light serves to

frighten away enemies, and by others to guide the male to the female. At last, Mr. Belt (12. 'The Naturalist in

Nicaragua,' 1874, pp. 316320. On the phosphorescence of the eggs, see 'Annals and Magazine of Natural

History,' Nov. 1871, p. 372.) appears to have solved the difficulty: he finds that all the Lampyridae which he

has tried are highly distasteful to insectivorous mammals and birds. Hence it is in accordance with Mr. Bates'

view, hereafter to be explained, that many insects mimic the Lampyridae closely, in order to be mistaken for

them, and thus to escape destruction. He further believes that the luminous species profit by being at once

recognised as unpalatable. It is probable that the same explanation may be extended to the Elaters, both sexes

of which are highly luminous. It is not known why the wings of the female glowworm have not been

developed; but in her present state she closely resembles a larva, and as larvae are so largely preyed on by

many animals, we can understand why she has been rendered so much more luminous and conspicuous than

With insects of all kinds the males are commonly smaller than the females; and this difference can often be

detected even in the larval state. So considerable is the difference between the male and female cocoons of

the silkmoth (Bombyx mori), that in France they are separated by a particular mode of weighing. (13.

Robinet, 'Vers a Soie,' 1848, p. 207.) In the lower classes of the animal kingdom, the greater size of the

females seems generally to depend on their developing an enormous number of ova; and this may to a certain

extent hold good with insects. But Dr. Wallace has suggested a much more probable explanation. He finds,

after carefully attending to the development of the caterpillars of Bombyx cynthia and yamamai, and

especially to that of some dwarfed caterpillars reared from a second brood on unnatural food, "that in

proportion as the individual moth is finer, so is the time required for its metamorphosis longer; and for this

reason the female, which is the larger and heavier insect, from having to carry her numerous eggs, will be

preceded by the male, which is smaller and has less to mature." (14. 'Transact. Ent. Soc.' 3rd series, vol. v. p.

486.) Now as most insects are shortlived, and as they are exposed to many dangers, it would manifestly be

advantageous to the female to be impregnated as soon as possible. This end would be gained by the males

being first matured in large numbers ready for the advent of the females; and this again would naturally

follow, as Mr. A.R. Wallace has remarked (15. 'Journal of Proc. Ent. Soc.' Feb. 4, 1867, p. lxxi.), through

natural selection; for the smaller males would be first matured, and thus would procreate a large number of

offspring which would inherit the reduced size of their male parents, whilst the larger males from being

There are, however, exceptions to the rule of male insects being smaller than the females: and some of these

exceptions are intelligible. Size and strength would be an advantage to the males, which fight for the

possession of the females; and in these cases, as with the stagbeetle (Lucanus), the males are larger than the

females. There are, however, other beetles which are not known to fight together, of which the males exceed

the females in size; and the meaning of this fact is not known; but in some of these cases, as with the huge

Dynastes and Megasoma, we can at least see that there would be no necessity for the males to be smaller than

the females, in order to be matured before them, for these beetles are not shortlived, and there would be

ample time for the pairing of the sexes. So again, male dragonflies (Libellulidae) are sometimes sensibly

larger, and never smaller, than the females (16. For this and other statements on the size of the sexes, see

Kirby and Spence, ibid. vol. iii. p. 300; on the duration of life in insects, see p. 344.); and as Mr. MacLachlan

believes, they do not generally pair with the females until a week or fortnight has elapsed, and until they have

assumed their proper masculine colours. But the most curious case, shewing on what complex and

easilyoverlooked relations, so trifling a character as difference in size between the sexes may depend, is that

of the aculeate Hymenoptera; for Mr. F. Smith informs me that throughout nearly the whole of this large

group, the males, in accordance with the general rule, are smaller than the females, and emerge about a week

before them; but amongst the Bees, the males of Apis mellifica, Anthidium manicatum, and Anthophora

acervorum, and amongst the Fossores, the males of the Methoca ichneumonides, are larger than the females.

The explanation of this anomaly is that a marriage flight is absolutely necessary with these species, and the

male requires great strength and size in order to carry the female through the air. Increased size has here been

acquired in opposition to the usual relation between size and the period of development, for the males, though

We will now review the several Orders, selecting such facts as more particularly concern us. The Lepidoptera

The members of this lowly organised order are wingless, dullcoloured, minute insects, with ugly, almost

misshapen heads and bodies. Their sexes do not differ, but they are interesting as shewing us that the males

pay sedulous court to the females even low down in the animal scale. Sir J. Lubbock (17. 'Transact. Linnean

Soc.' vol. xxvi. 1868, p. 296.) says: "it is very amusing to see these little creatures (Smynthurus luteus)

coquetting together. The male, which is much smaller than the female, runs round her, and they butt one

another, standing face to face and moving backward and forward like two playful lambs. Then the female

pretends to run away and the male runs after her with a queer appearance of anger, gets in front and stands

facing her again; then she turns coyly round, but he, quicker and more active, scuttles round too, and seems to

whip her with his antennae; then for a bit they stand face to face, play with their antennae, and seem to be all

The sexes differ little in colour. The greatest difference, known to Mr. F. Walker, is in the genus Bibio, in

which the males are blackish or quite black, and the females obscure brownishorange. The genus

Elaphomyia, discovered by Mr. Wallace (18. 'The Malay Archipelago,' vol. ii. 1869, p. 313.) in New Guinea,

is highly remarkable, as the males are furnished with horns, of which the females are quite destitute. The

horns spring from beneath the eyes, and curiously resemble those of a stag, being either branched or

palmated. In one of the species, they equal the whole body in length. They might be thought to be adapted for

fighting, but as in one species they are of a beautiful pink colour, edged with black, with a pale central stripe,

and as these insects have altogether a very elegant appearance, it is perhaps more probable that they serve as

ornaments. That the males of some Diptera fight together is certain; Prof. Westwood (19. 'Modern

Classification of Insects,' vol. ii. 1840, p. 526.) has several times seen this with the Tipulae. The males of

other Diptera apparently try to win the females by their music: H. Muller (20. 'Anwendung,' etc., 'Verh. d. n.

V. Jahrg.' xxix. p. 80. Mayer, in 'American Naturalist,' 1874, p. 236.) watched for some time two males of an

Eristalis courting a female; they hovered above her, and flew from side to side, making a high humming noise

at the same time. Gnats and mosquitoes (Culicidae) also seem to attract each other by humming; and Prof.

Mayer has recently ascertained that the hairs on the antennae of the male vibrate in unison with the notes of a

tuningfork, within the range of the sounds emitted by the female. The longer hairs vibrate sympathetically

with the graver notes, and the shorter hairs with the higher ones. Landois also asserts that he has repeatedly

drawn down a whole swarm of gnats by uttering a particular note. It may be added that the mental faculties of

the Diptera are probably higher than in most other insects, in accordance with their highly developed

nervous system. (21. See Mr. B.T. Lowne's interesting work, 'On the Anatomy of the Blowfly, Musca

vomitoria,' 1870, p. 14. He remarks (p. 33) that, "the captured flies utter a peculiar plaintive note, and that

Mr. J.W. Douglas, who has particularly attended to the British species, has kindly given me an account of

their sexual differences. The males of some species are furnished with wings, whilst the females are wingless;

the sexes differ in the form of their bodies, elytra, antennae and tarsi; but as the signification of these

differences are unknown, they may be here passed over. The females are generally larger and more robust

than the males. With British, and, as far as Mr. Douglas knows, with exotic species, the sexes do not

commonly differ much in colour; but in about six British species the male is considerably darker than the

female, and in about four other species the female is darker than the male. Both sexes of some species are

beautifully coloured; and as these insects emit an extremely nauseous odour, their conspicuous colours may

serve as a signal that they are unpalatable to insectivorous animals. In some few cases their colours appear to

be directly protective: thus Prof. Hoffmann informs me that he could hardly distinguish a small pink and

green species from the buds on the trunks of limetrees, which this insect frequents.

Some species of Reduvidae make a stridulating noise; and, in the case of Pirates stridulus, this is said (22.

Westwood, 'Modern Classification of Insects,' vol. ii. p. 473.) to be effected by the movement of the neck

within the prothoracic cavity. According to Westring, Reduvius personatus also stridulates. But I have no

reason to suppose that this is a sexual character, excepting that with nonsocial insects there seems to be no

Every one who has wandered in a tropical forest must have been astonished at the din made by the male

Cicadae. The females are mute; as the Grecian poet Xenarchus says, "Happy the Cicadas live, since they all

have voiceless wives." The noise thus made could be plainly heard on board the "Beagle," when anchored at

a quarter of a mile from the shore of Brazil; and Captain Hancock says it can be heard at the distance of a

mile. The Greeks formerly kept, and the Chinese now keep these insects in cages for the sake of their song, so

that it must be pleasing to the ears of some men. (23. These particulars are taken from Westwood's 'Modern

Classification of Insects,' vol. ii. 1840, p. 422. See, also, on the Fulgoridae, Kirby and Spence, 'Introduct.' vol.

ii. p. 401.) The Cicadidae usually sing during the day, whilst the Fulgoridae appear to be nightsongsters.

The sound, according to Landois (24. 'Zeitschrift fur wissenschaft Zoolog.' B. xvii. 1867, ss. 152158.), is

produced by the vibration of the lips of the spiracles, which are set into motion by a current of air emitted

from the tracheae; but this view has lately been disputed. Dr. Powell appears to have proved (25.

'Transactions of the New Zealand Institute,' vol. v. 1873, p. 286.) that it is produced by the vibration of a

membrane, set into action by a special muscle. In the living insect, whilst stridulating, this membrane can be

seen to vibrate; and in the dead insect the proper sound is heard, if the muscle, when a little dried and

hardened, is pulled with the point of a pin. In the female the whole complex musical apparatus is present, but

With respect to the object of the music, Dr. Hartman, in speaking of the Cicada septemdecim of the United

States, says (26. I am indebted to Mr. Walsh for having sent me this extract from 'A Journal of the Doings of

Cicada septemdecim,' by Dr. Hartman.), "the drums are now (June 6th and 7th, 1851) heard in all directions.

This I believe to be the marital summons from the males. Standing in thick chestnut sprouts about as high as

my head, where hundreds were around me, I observed the females coming around the drumming males." He

adds, "this season (Aug. 1868) a dwarf peartree in my garden produced about fifty larvae of Cic. pruinosa;

and I several times noticed the females to alight near a male while he was uttering his clanging notes." Fritz

Muller writes to me from S. Brazil that he has often listened to a musical contest between two or three males

of a species with a particularly loud voice, seated at a considerable distance from each other: as soon as one

had finished his song, another immediately began, and then another. As there is so much rivalry between the

males, it is probable that the females not only find them by their sounds, but that, like female birds, they are

I have not heard of any wellmarked cases of ornamental differences between the sexes of the Homoptera.

Mr. Douglas informs me that there are three British species, in which the male is black or marked with black

The males in the three saltatorial families in this Order are remarkable for their musical powers, namely the

Achetidae or crickets, the Locustidae for which there is no equivalent English name, and the Acridiidae or

grasshoppers. The stridulation produced by some of the Locustidae is so loud that it can be heard during the

night at the distance of a mile (27. L. Guilding, 'Transactions of the Linnean Society,' vol. xv. p. 154.); and

that made by certain species is not unmusical even to the human ear, so that the Indians on the Amazons keep

them in wicker cages. All observers agree that the sounds serve either to call or excite the mute females. With

respect to the migratory locusts of Russia, Korte has given (28. I state this on the authority of Koppen, 'Uber

die Heuschrecken in Sudrussland,' 1866, p. 32, for I have in vain endeavoured to procure Korte's work.) an

interesting case of selection by the female of a male. The males of this species (Pachytylus migratorius)

whilst coupled with the female stridulate from anger or jealousy, if approached by other males. The

housecricket when surprised at night uses its voice to warn its fellows. (29. Gilbert White, 'Natural History

of Selborne,' vol. ii. 1825, p. 262.) In North America the Katydid (Platyphyllum concavum, one of the

Locustidae) is described (30. Harris, 'Insects of New England,' 1842, p. 128.) as mounting on the upper

branches of a tree, and in the evening beginning "his noisy babble, while rival notes issue from the

neighbouring trees, and the groves resound with the call of Katydidshe did the livelong night." Mr.

Bates, in speaking of the European field cricket (one of the Achetidae), says "the male has been observed to

place himself in the evening at the entrance of his burrow, and stridulate until a female approaches, when the

louder notes are succeeded by a more subdued tone, whilst the successful musician caresses with his antennae

the mate he has won." (31. 'The Naturalist on the Amazons,' vol. i. 1863, p. 252. Mr. Bates gives a very

interesting discussion on the gradations in the musical apparatus of the three families. See also Westwood,

'Modern Classification of Insects,' vol. ii. pp. 445 and 453.) Dr. Scudder was able to excite one of these

insects to answer him, by rubbing on a file with a quill. (32. 'Proceedings of the Boston Society of Natural

History,' vol. xi. April 1868.) In both sexes a remarkable auditory apparatus has been discovered by Von

Siebold, situated in the front legs. (33. 'Nouveau Manuel d'Anat. Comp.' (French translat.), tom. 1, 1850, p.

[Fig.11. Gryllus campestris (from Landois). Righthand figure, under side of part of a wingnervure, much

magnified, showing the teeth, st. Lefthand figure, upper surface of wingcover, with the projecting, smooth

In the three Families the sounds are differently produced. In the males of the Achetidae both wingcovers

have the same apparatus; and this in the fieldcricket (see Gryllus campestris, Fig. 11) consists, as described

by Landois (34. 'Zeitschrift fur wissenschaft. Zoolog.' B. xvii. 1867, s. 117.), of from 131 to 138 sharp,

transverse ridges or teeth (st) on the under side of one of the nervures of the wingcover. This toothed

nervure is rapidly scraped across a projecting, smooth, hard nervure (r) on the upper surface of the opposite

wing. First one wing is rubbed over the other, and then the movement is reversed. Both wings are raised a

little at the same time, so as to increase the resonance. In some species the wingcovers of the males are

furnished at the base with a talclike plate. (35. Westwood, 'Modern Classification of Insects,' vol. i. p. 440.)

I here give a drawing (Fig. 12) of the teeth on the under side of the nervure of another species of Gryllus, viz.,

G. domesticus. With respect to the formation of these teeth, Dr. Gruber has shewn (36. 'Ueber der Tonapparat

der Locustiden, ein Beitrag zum Darwinismus,' 'Zeitschrift fur wissenschaft. Zoolog.' B. xxii. 1872, p. 100.)

that they have been developed by the aid of selection, from the minute scales and hairs with which the wings

and body are covered, and I came to the same conclusion with respect to those of the Coleoptera. But Dr.

Gruber further shews that their development is in part directly due to the stimulus from the friction of one

In the Locustidae the opposite wingcovers differ from each other in structure (Fig. 13), and the action

cannot, as in the last family, be reversed. The left wing, which acts as the bow, lies over the right wing which

serves as the fiddle. One of the nervures (a) on the under surface of the former is finely serrated, and is

scraped across the prominent nervures on the upper surface of the opposite or right wing. In our British

Phasgonura viridissima it appeared to me that the serrated nervure is rubbed against the rounded hindcorner

of the opposite wing, the edge of which is thickened, coloured brown, and very sharp. In the right wing, but

not in the left, there is a little plate, as transparent as talc, surrounded by nervures, and called the speculum. In

Ephippiger vitium, a member of this same family, we have a curious subordinate modification; for the

wingcovers are greatly reduced in size, but "the posterior part of the prothorax is elevated into a kind of

dome over the wingcovers, and which has probably the effect of increasing the sound." (37. Westwood

We thus see that the musical apparatus is more differentiated or specialised in the Locustidae (which include,

I believe, the most powerful performers in the Order), than in the Achetidae, in which both wingcovers have

the same structure and the same function. (38. Landois, 'Zeitschrift fur wissenschaft Zoolog.' B. xvii. 1867,

ss. 121, 122.) Landois, however, detected in one of the Locustidae, namely in Decticus, a short and narrow

row of small teeth, mere rudiments, on the inferior surface of the right wingcover, which underlies the other

and is never used as the bow. I observed the same rudimentary structure on the under side of the right

wingcover in Phasgonura viridissima. Hence we may infer with confidence that the Locustidae are

descended from a form, in which, as in the existing Achetidae, both wingcovers had serrated nervures on the

under surface, and could be indifferently used as the bow; but that in the Locustidae the two wingcovers

gradually became differentiated and perfected, on the principle of the division of labour, the one to act

exclusively as the bow, and the other as the fiddle. Dr. Gruber takes the same view, and has shewn that

rudimentary teeth are commonly found on the inferior surface of the right wing. By what steps the more

simple apparatus in the Achetidae originated, we do not know, but it is probable that the basal portions of the

wing covers originally overlapped each other as they do at present; and that the friction of the nervures

produced a grating sound, as is now the case with the wingcovers of the females. (39. Mr. Walsh also

informs me that he has noticed that the female of the Platyphyllum concavum, "when captured makes a feeble

grating noise by shuffling her wingcovers together.") A grating sound thus occasionally and accidentally

made by the males, if it served them ever so little as a lovecall to the females, might readily have been

intensified through sexual selection, by variations in the roughness of the nervures having been continually

[Fig.14. Hindleg of Stenobothrus pratorum: r, the stridulating ridge; lower figure, the teeth forming the

Fig.15. Pneumora (from specimens in the British Museum). Upper figure, male; lower figure, female.]

In the last and third family, namely the Acridiidae or grasshoppers, the stridulation is produced in a very

different manner, and according to Dr. Scudder, is not so shrill as in the preceding Families. The inner

surface of the femur (Fig. 14, r) is furnished with a longitudinal row of minute, elegant, lancetshaped, elastic

teeth, from 85 to 93 in number (40. Landois, ibid. s. 113.); and these are scraped across the sharp, projecting

nervures on the wingcovers, which are thus made to vibrate and resound. Harris (41. 'Insects of New

England,' 1842, p. 133.) says that when one of the males begins to play, he first "bends the shank of the

hindleg beneath the thigh, where it is lodged in a furrow designed to receive it, and then draws the leg

briskly up and down. He does not play both fiddles together, but alternately, first upon one and then on the

other." In many species, the base of the abdomen is hollowed out into a great cavity which is believed to act

as a resounding board. In Pneumora (Fig. 15), a S. African genus belonging to the same family, we meet with

a new and remarkable modification; in the males a small notched ridge projects obliquely from each side of

the abdomen, against which the hind femora are rubbed. (42. Westwood, 'Modern Classification,' vol i. p.

462.) As the male is furnished with wings (the female being wingless), it is remarkable that the thighs are not

rubbed in the usual manner against the wingcovers; but this may perhaps be accounted for by the unusually

small size of the hindlegs. I have not been able to examine the inner surface of the thighs, which, judging

from analogy, would be finely serrated. The species of Pneumora have been more profoundly modified for

the sake of stridulation than any other orthopterous insect; for in the male the whole body has been converted

into a musical instrument, being distended with air, like a great pellucid bladder, so as to increase the

resonance. Mr. Trimen informs me that at the Cape of Good Hope these insects make a wonderful noise

In the three foregoing families, the females are almost always destitute of an efficient musical apparatus. But

there are a few exceptions to this rule, for Dr. Gruber has shewn that both sexes of Ephippiger vitium are thus

provided; though the organs differ in the male and female to a certain extent. Hence we cannot suppose that

they have been transferred from the male to the female, as appears to have been the case with the secondary

sexual characters of many other animals. They must have been independently developed in the two sexes,

which no doubt mutually call to each other during the season of love. In most other Locustidae (but not

according to Landois in Decticus) the females have rudiments of the stridulatory organs proper to the male;

from whom it is probable that these have been transferred. Landois also found such rudiments on the under

surface of the wingcovers of the female Achetidae, and on the femora of the female Acridiidae. In the

Homoptera, also, the females have the proper musical apparatus in a functionless state; and we shall hereafter

meet in other divisions of the animal kingdom with many instances of structures proper to the male being

Landois has observed another important fact, namely, that in the females of the Acridiidae, the stridulating

teeth on the femora remain throughout life in the same condition in which they first appear during the larval

state in both sexes. In the males, on the other hand, they become further developed, and acquire their perfect

From the facts now given, we see that the means by which the males of the Orthoptera produce their sounds

are extremely diversified, and are altogether different from those employed by the Homoptera. (43. Landois

has recently found in certain Orthoptera rudimentary structures closely similar to the soundproducing

organs in the Homoptera; and this is a surprising fact. See 'Zeitschrift fur wissenschaft Zoolog.' B. xxii. Heft

3, 1871, p. 348.) But throughout the animal kingdom we often find the same object gained by the most

diversified means; this seems due to the whole organisation having undergone multifarious changes in the

course of ages, and as part after part varied different variations were taken advantage of for the same general

purpose. The diversity of means for producing sound in the three families of the Orthoptera and in the

Homoptera, impresses the mind with the high importance of these structures to the males, for the sake of

calling or alluring the females. We need feel no surprise at the amount of modification which the Orthoptera

have undergone in this respect, as we now know, from Dr. Scudder's remarkable discovery (44. 'Transactions,

Entomological Society,' 3rd series, vol. ii. ('Journal of Proceedings,' p. 117).), that there has been more than

ample time. This naturalist has lately found a fossil insect in the Devonian formation of New Brunswick,

which is furnished with "the wellknown tympanum or stridulating apparatus of the male Locustidae." The

insect, though in most respects related to the Neuroptera, appears, as is so often the case with very ancient

I have but little more to say on the Orthoptera. Some of the species are very pugnacious: when two male

fieldcrickets (Gryllus campestris) are confined together, they fight till one kills the other; and the species of

Mantis are described as manoeuvring with their swordlike frontlimbs, like hussars with their sabres. The

Chinese keep these insects in little bamboo cages, and match them like gamecocks. (45. Westwood,

'Modern Classification of Insects,' vol. i. p. 427; for crickets, p. 445.) With respect to colour, some exotic

locusts are beautifully ornamented; the posterior wings being marked with red, blue, and black; but as

throughout the Order the sexes rarely differ much in colour, it is not probable that they owe their bright tints

to sexual selection. Conspicuous colours may be of use to these insects, by giving notice that they are

unpalatable. Thus it has been observed (46. Mr. Ch. Horne, in 'Proceedings of the Entomological Society,'

May 3, 1869, p. xii.) that a brightcoloured Indian locust was invariably rejected when offered to birds and

lizards. Some cases, however, are known of sexual differences in colour in this Order. The male of an

American cricket (47. The Oecanthus nivalis, Harris, 'Insects of New England,' 1842, p. 124. The two sexes

of OE. pellucidus of Europe differ, as I hear from Victor Carus, in nearly the same manner.) is described as

being as white as ivory, whilst the female varies from almost white to greenishyellow or dusky. Mr. Walsh

informs me that the adult male of Spectrum femoratum (one of the Phasmidae) "is of a shining

brownishyellow colour; the adult female being of a dull, opaque, cinereous brown; the young of both sexes

being green." Lastly, I may mention that the male of one curious kind of cricket (48. Platyblemnus:

Westwood, 'Modern Classification,' vol. i. p. 447.) is furnished with "a long membranous appendage, which

Little need here be said, except as to colour. In the Ephemeridae the sexes often differ slightly in their

obscure tints (49. B.D. Walsh, the 'Pseudoneuroptera of Illinois,' in 'Proceedings of the Entomological

Society of Philadelphia,' 1862, p. 361.); but it is not probable that the males are thus rendered attractive to the

females. The Libellulidae, or dragonflies, are ornamented with splendid green, blue, yellow, and vermilion

metallic tints; and the sexes often differ. Thus, as Prof. Westwood remarks (50. 'Modern Classification,' vol.

ii. p. 37.), the males of some of the Agrionidae, "are of a rich blue with black wings, whilst the females are

fine green with colourless wings." But in Agrion Ramburii these colours are exactly reversed in the two

sexes. (51. Walsh, ibid. p. 381. I am indebted to this naturalist for the following facts on Hetaerina, Anax, and

Gomphus.) In the extensive N. American genus of Hetaerina, the males alone have a beautiful carmine spot at

the base of each wing. In Anax junius the basal part of the abdomen in the male is a vivid ultramarine blue,

and in the female grassgreen. In the allied genus Gomphus, on the other hand, and in some other genera, the

sexes differ but little in colour. In closelyallied forms throughout the animal kingdom, similar cases of the

sexes differing greatly, or very little, or not at all, are of frequent occurrence. Although there is so wide a

difference in colour between the sexes of many Libellulidae, it is often difficult to say which is the more

brilliant; and the ordinary coloration of the two sexes is reversed, as we have just seen, in one species of

Agrion. It is not probable that their colours in any case have been gained as a protection. Mr. MacLachlan,

who has closely attended to this family, writes to me that dragonfliesthe tyrants of the insectworldare

the least liable of any insect to be attacked by birds or other enemies, and he believes that their bright colours

serve as a sexual attraction. Certain dragonflies apparently are attracted by particular colours: Mr. Patterson

observed (52. 'Transactions, Ent. Soc.' vol. i. 1836, p. lxxxi.) that the Agrionidae, of which the males are blue,

settled in numbers on the blue float of a fishing line; whilst two other species were attracted by shining white

It is an interesting fact, first noticed by Schelver, that, in several genera belonging to two subfamilies, the

males on first emergence from the pupal state, are coloured exactly like the females; but that their bodies in a

short time assume a conspicuous milkyblue tint, owing to the exudation of a kind of oil, soluble in ether and

alcohol. Mr. MacLachlan believes that in the male of Libellula depressa this change of colour does not occur

until nearly a fortnight after the metamorphosis, when the sexes are ready to pair.

Certain species of Neurothemis present, according to Brauer (53. See abstract in the 'Zoological Record' for

1867, p. 450.), a curious case of dimorphism, some of the females having ordinary wings, whilst others have

them "very richly netted, as in the males of the same species." Brauer "explains the phenomenon on

Darwinian principles by the supposition that the close netting of the veins is a secondary sexual character in

the males, which has been abruptly transferred to some of the females, instead of, as generally occurs, to all

of them." Mr. MacLachlan informs me of another instance of dimorphism in several species of Agrion, in

which some individuals are of an orange colour, and these are invariably females. This is probably a case of

reversion; for in the true Libellulae, when the sexes differ in colour, the females are orange or yellow; so that

supposing Agrion to be descended from some primordial form which resembled the typical Libellulae in its

sexual characters, it would not be surprising that a tendency to vary in this manner should occur in the

Although many dragonflies are large, powerful, and fierce insects, the males have not been observed by Mr.

MacLachlan to fight together, excepting, as he believes, in some of the smaller species of Agrion. In another

group in this Order, namely, the Termites or white ants, both sexes at the time of swarming may be seen

running about, "the male after the female, sometimes two chasing one female, and contending with great

eagerness who shall win the prize." (54. Kirby and Spence, 'Introduction to Entomology,' vol. ii. 1818, p. 35.)

The Atropos pulsatorius is said to make a noise with its jaws, which is answered by other individuals. (55.

That inimitable observer, M. Fabre (56. See an interesting article, 'The Writings of Fabre,' in 'Nat. Hist.

Review,' April 1862, p. 122.), in describing the habits of Cerceris, a wasplike insect, remarks that "fights

frequently ensue between the males for the possession of some particular female, who sits an apparently

unconcerned beholder of the struggle for supremacy, and when the victory is decided, quietly flies away in

company with the conqueror." Westwood (57. 'Journal of Proceedings of Entomological Society,' Sept. 7,

1863, p. 169.) says that the males of one of the sawflies (Tenthredinae) "have been found fighting together,

with their mandibles locked." As M. Fabre speaks of the males of Cerceris striving to obtain a particular

female, it may be well to bear in mind that insects belonging to this Order have the power of recognising each

other after long intervals of time, and are deeply attached. For instance, Pierre Huber, whose accuracy no one

doubts, separated some ants, and when, after an interval of four months, they met others which had formerly

belonged to the same community, they recognised and caressed one another with their antennae. Had they

been strangers they would have fought together. Again, when two communities engage in a battle, the ants on

the same side sometimes attack each other in the general confusion, but they soon perceive their mistake, and

the one ant soothes the other. (58. P. Huber, 'Recherches sur les Moeurs des Fourmis,' 1810, pp. 150, 165.)

In this Order slight differences in colour, according to sex, are common, but conspicuous differences are rare

except in the family of Bees; yet both sexes of certain groups are so brilliantly colouredfor instance in

Chrysis, in which vermilion and metallic greens prevailthat we are tempted to attribute the result to sexual

selection. In the Ichneumonidae, according to Mr. Walsh (59. 'Proceedings of the Entomological Society of

Philadelphia,' 1866, pp. 238, 239.), the males are almost universally lightercoloured than the females. On

the other hand, in the Tenthredinidae the males are generally darker than the females. In the Siricidae the

sexes frequently differ; thus the male of Sirex juvencus is banded with orange, whilst the female is dark

purple; but it is difficult to say which sex is the more ornamented. In Tremex columbae the female is much

brighter coloured than the male. I am informed by Mr. F. Smith, that the male ants of several species are

In the family of Bees, especially in the solitary species, as I hear from the same entomologist, the sexes often

differ in colour. The males are generally the brighter, and in Bombus as well as in Apathus, much more

variable in colour than the females. In Anthophora retusa the male is of a rich fulvousbrown, whilst the

female is quite black: so are the females of several species of Xylocopa, the males being bright yellow. On

the other hand the females of some species, as of Andraena fulva, are much brighter coloured than the males.

Such differences in colour can hardly be accounted for by the males being defenceless and thus requiring

protection, whilst the females are well defended by their stings. H. Muller (60. 'Anwendung der Darwinschen

Lehre auf Bienen,' Verh. d. n. V. Jahrg. xxix.), who has particularly attended to the habits of bees, attributes

these differences in colour in chief part to sexual selection. That bees have a keen perception of colour is

certain. He says that the males search eagerly and fight for the possession of the females; and he accounts

through such contests for the mandibles of the males being in certain species larger than those of the females.

In some cases the males are far more numerous than the females, either early in the season, or at all times and

places, or locally; whereas the females in other cases are apparently in excess. In some species the more

beautiful males appear to have been selected by the females; and in others the more beautiful females by the

males. Consequently in certain genera (Muller, p. 42), the males of the several species differ much in

appearance, whilst the females are almost indistinguishable; in other genera the reverse occurs. H. Muller

believes (p. 82) that the colours gained by one sex through sexual selection have often been transferred in a

variable degree to the other sex, just as the pollencollecting apparatus of the female has often been

transferred to the male, to whom it is absolutely useless. (61. M. Perrier in his article 'la Selection sexuelle

d'apres Darwin' ('Revue Scientifique,' Feb. 1873, p. 868), without apparently having reflected much on the

subject, objects that as the males of social bees are known to be produced from unfertilised ova, they could

not transmit new characters to their male offspring. This is an extraordinary objection. A female bee fertilised

by a male, which presented some character facilitating the union of the sexes, or rendering him more

attractive to the female, would lay eggs which would produce only females; but these young females would

next year produce males; and will it be pretended that such males would not inherit the characters of their

male grandfathers? To take a case with ordinary animals as nearly parallel as possible: if a female of any

white quadruped or bird were crossed by a male of a black breed, and the male and female offspring were

paired together, will it be pretended that the grandchildren would not inherit a tendency to blackness from

their male grandfather? The acquirement of new characters by the sterile workerbees is a much more

difficult case, but I have endeavoured to shew in my 'Origin of Species,' how these sterile beings are

Mutilla Europaea makes a stridulating noise; and according to Goureau (62. Quoted by Westwood, 'Modern

Classification of Insects,' vol. ii. p. 214.) both sexes have this power. He attributes the sound to the friction of

the third and preceding abdominal segments, and I find that these surfaces are marked with very fine

concentric ridges; but so is the projecting thoracic collar into which the head articulates, and this collar, when

scratched with the point of a needle, emits the proper sound. It is rather surprising that both sexes should have

the power of stridulating, as the male is winged and the female wingless. It is notorious that Bees express

certain emotions, as of anger, by the tone of their humming; and according to H. Muller (p. 80), the males of

Many beetles are coloured so as to resemble the surfaces which they habitually frequent, and they thus escape

detection by their enemies. Other species, for instance diamondbeetles, are ornamented with splendid

colours, which are often arranged in stripes, spots, crosses, and other elegant patterns. Such colours can

hardly serve directly as a protection, except in the case of certain flowerfeeding species; but they may serve

as a warning or means of recognition, on the same principle as the phosphorescence of the glowworm. As

with beetles the colours of the two sexes are generally alike, we have no evidence that they have been gained

through sexual selection; but this is at least possible, for they have been developed in one sex and then

transferred to the other; and this view is even in some degree probable in those groups which possess other

well marked secondary sexual characters. Blind beetles, which cannot of course behold each other's beauty,

never, as I hear from Mr. Waterhouse, jun., exhibit bright colours, though they often have polished coats; but

the explanation of their obscurity may be that they generally inhabit caves and other obscure stations.

Some Longicorns, especially certain Prionidae, offer an exception to the rule that the sexes of beetles do not

differ in colour. Most of these insects are large and splendidly coloured. The males in the genus Pyrodes (63.

Pyrodes pulcherrimus, in which the sexes differ conspicuously, has been described by Mr. Bates in 'Transact.

Ent. Soc.' 1869, p. 50. I will specify the few other cases in which I have heard of a difference in colour

between the sexes of beetles. Kirby and Spence ('Introduct. to Entomology,' vol. iii. p. 301) mention a

Cantharis, Meloe, Rhagium, and the Leptura testacea; the male of the latter being testaceous, with a black

thorax, and the female of a dull red all over. These two latter beetles belong to the family of Longicorns.

Messrs. R. Trimen and Waterhouse, jun., inform me of two Lamellicorns, viz., a Peritrichia and Trichius, the

male of the latter being more obscurely coloured than the female. In Tillus elongatus the male is black, and

the female always, as it is believed, of a dark blue colour, with a red thorax. The male, also, of Orsodacna

atra, as I hear from Mr. Walsh, is black, the female (the so called O. ruficollis) having a rufous thorax.),

which I saw in Mr. Bates's collection, are generally redder but rather duller than the females, the latter being

coloured of a more or less splendid goldengreen. On the other hand, in one species the male is

goldengreen, the female being richly tinted with red and purple. In the genus Esmeralda the sexes differ so

greatly in colour that they have been ranked as distinct species; in one species both are of a beautiful shining

green, but the male has a red thorax. On the whole, as far as I could judge, the females of those Prionidae, in

which the sexes differ, are coloured more richly than the males, and this does not accord with the common

[Fig.16. Chalcosoma atlas. Upper figure, male (reduced); lower figure, female (nat. size).

Fig. 20. Onthophagus rangifer, enlarged. (In Figs. 17 to 20 the lefthand figures are males.)]

A most remarkable distinction between the sexes of many beetles is presented by the great horns which rise

from the head, thorax, and clypeus of the males; and in some few cases from the under surface of the body.

These horns, in the great family of the Lamellicorns, resemble those of various quadrupeds, such as stags,

rhinoceroses, etc., and are wonderful both from their size and diversified shapes. Instead of describing them, I

have given figures of the males and females of some of the more remarkable forms. (Figs. 16 to 20.) The

females generally exhibit rudiments of the horns in the form of small knobs or ridges; but some are destitute

of even the slightest rudiment. On the other hand, the horns are nearly as well developed in the female as in

the male Phanaeus lancifer; and only a little less well developed in the females of some other species of this

genus and of Copris. I am informed by Mr. Bates that the horns do not differ in any manner corresponding

with the more important characteristic differences between the several subdivisions of the family: thus within

the same section of the genus Onthophagus, there are species which have a single horn, and others which

In almost all cases, the horns are remarkable from their excessive variability; so that a graduated series can be

formed, from the most highly developed males to others so degenerate that they can barely be distinguished

from the females. Mr. Walsh (64. 'Proceedings of the Entomological Society of Philadephia,' 1864, p. 228.)

found that in Phanaeus carnifex the horns were thrice as long in some males as in others. Mr. Bates, after

examining above a hundred males of Onthophagus rangifer (Fig. 20), thought that he had at last discovered a

species in which the horns did not vary; but further research proved the contrary.

The extraordinary size of the horns, and their widely different structure in closelyallied forms, indicate that

they have been formed for some purpose; but their excessive variability in the males of the same species

leads to the inference that this purpose cannot be of a definite nature. The horns do not shew marks of

friction, as if used for any ordinary work. Some authors suppose (65. Kirby and Spence, 'Introduction to

Entomology,' vol. iii. P. 300.) that as the males wander about much more than the females, they require horns

as a defence against their enemies; but as the horns are often blunt, they do not seem well adapted for

defence. The most obvious conjecture is that they are used by the males for fighting together; but the males

have never been observed to fight; nor could Mr. Bates, after a careful examination of numerous species, find

any sufficient evidence, in their mutilated or broken condition, of their having been thus used. If the males

had been habitual fighters, the size of their bodies would probably have been increased through sexual

selection, so as to have exceeded that of the females; but Mr. Bates, after comparing the two sexes in above a

hundred species of the Copridae, did not find any marked difference in this respect amongst welldeveloped

individuals. In Lethrus, moreover, a beetle belonging to the same great division of the Lamellicorns, the

males are known to fight, but are not provided with horns, though their mandibles are much larger than those

The conclusion that the horns have been acquired as ornaments is that which best agrees with the fact of their

having been so immensely, yet not fixedly, developed,as shewn by their extreme variability in the same

species, and by their extreme diversity in closelyallied species. This view will at first appear extremely

improbable; but we shall hereafter find with many animals standing much higher in the scale, namely fishes,

amphibians, reptiles and birds, that various kinds of crests, knobs, horns and combs have been developed

Fig.22. Onitis furcifer. Lefthand figure, male, viewed laterally. Righthand figure, female. a. Rudiment of

The males of Onitis furcifer (Fig. 21), and of some other species of the genus, are furnished with singular

projections on their anterior femora, and with a great fork or pair of horns on the lower surface of the thorax.

Judging from other insects, these may aid the male in clinging to the female. Although the males have not

even a trace of a horn on the upper surface of the body, yet the females plainly exhibit a rudiment of a single

horn on the head (Fig. 22, a), and of a crest (b) on the thorax. That the slight thoracic crest in the female is a

rudiment of a projection proper to the male, though entirely absent in the male of this particular species, is

clear: for the female of Bubas bison (a genus which comes next to Onitis) has a similar slight crest on the

thorax, and the male bears a great projection in the same situation. So, again, there can hardly be a doubt that

the little point (a) on the head of the female Onitis furcifer, as well as on the head of the females of two or

three allied species, is a rudimentary representative of the cephalic horn, which is common to the males of so

The old belief that rudiments have been created to complete the scheme of nature is here so far from holding

good, that we have a complete inversion of the ordinary state of things in the family. We may reasonably

suspect that the males originally bore horns and transferred them to the females in a rudimentary condition, as

in so many other Lamellicorns. Why the males subsequently lost their horns, we know not; but this may have

been caused through the principle of compensation, owing to the development of the large horns and

projections on the lower surface; and as these are confined to the males, the rudiments of the upper horns on

[Fig. 23. Bledius taurus, magnified. Lefthand figure, male; righthand figure, female.]

The cases hitherto given refer to the Lamellicorns, but the males of some few other beetles, belonging to two

widely distinct groups, namely, the Curculionidae and Staphylinidae, are furnished with hornsin the former

on the lower surface of the body (66. Kirby and Spence, 'Introduction to Entomology,' vol. iii. p. 329.), in the

latter on the upper surface of the head and thorax. In the Staphylinidae, the horns of the males are

extraordinarily variable in the same species, just as we have seen with the Lamellicorns. In Siagonium we

have a case of dimorphism, for the males can be divided into two sets, differing greatly in the size of their

bodies and in the development of their horns, without intermediate gradations. In a species of Bledius (Fig.

23), also belonging to the Staphylinidae, Professor Westwood states that, "male specimens can be found in

the same locality in which the central horn of the thorax is very large, but the horns of the head quite

rudimental; and others, in which the thoracic horn is much shorter, whilst the protuberances on the head are

long." (67. 'Modern Classification of Insects,' vol. i. p. 172: Siagonium, p. 172. In the British Museum I

noticed one male specimen of Siagonium in an intermediate condition, so that the dimorphism is not strict.)

Here we apparently have a case of compensation, which throws light on that just given, of the supposed loss

Some male beetles, which seem illfitted for fighting, nevertheless engage in conflicts for the possession of

the females. Mr. Wallace (68. 'The Malay Archipelago,' vol. ii. 1869, p. 276. Riley, Sixth 'Report on Insects

of Missouri,' 1874, p. 115.) saw two males of Leptorhynchus angustatus, a linear beetle with a much

elongated rostrum, "fighting for a female, who stood close by busy at her boring. They pushed at each other

with their rostra, and clawed and thumped, apparently in the greatest rage." The smaller male, however, "soon

ran away, acknowledging himself vanquished." In some few cases male beetles are well adapted for fighting,

by possessing great toothed mandibles, much larger than those of the females. This is the case with the

common stagbeetle (Lucanus cervus), the males of which emerge from the pupal state about a week before

the other sex, so that several may often be seen pursuing the same female. At this season they engage in

fierce conflicts. When Mr. A.H. Davis (69. 'Entomological Magazine,' vol. i. 1833, p. 82. See also on the

conflicts of this species, Kirby and Spence, ibid. vol. iii. p. 314; and Westwood, ibid. vol. i. p. 187.) enclosed

two males with one female in a box, the larger male severely pinched the smaller one, until he resigned his

pretensions. A friend informs me that when a boy he often put the males together to see them fight, and he

noticed that they were much bolder and fiercer than the females, as with the higher animals. The males would

seize hold of his finger, if held in front of them, but not so the females, although they have stronger jaws. The

males of many of the Lucanidae, as well as of the abovementioned Leptorhynchus, are larger and more

powerful insects than the females. The two sexes of Lethrus cephalotes (one of the Lamellicorns) inhabit the

same burrow; and the male has larger mandibles than the female. If, during the breedingseason, a strange

male attempts to enter the burrow, he is attacked; the female does not remain passive, but closes the mouth of

the burrow, and encourages her mate by continually pushing him on from behind; and the battle lasts until the

aggressor is killed or runs away. (70. Quoted from Fischer, in 'Dict. Class. d'Hist. Nat.' tom. x. p. 324.) The

two sexes of another Lamellicorn beetle, the Ateuchus cicatricosus, live in pairs, and seem much attached to

each other; the male excites the females to roll the balls of dung in which the ova are deposited; and if she is

removed, he becomes much agitated. If the male is removed the female ceases all work, and as M. Brulerie

believes, would remain on the same spot until she died. (71. 'Ann. Soc. Entomolog. France,' 1866, as quoted

[Fig. 24. Chiasognathus Grantii, reduced. Upper figure, male; lower figure, female.]

The great mandibles of the male Lucanidae are extremely variable both in size and structure, and in this

respect resemble the horns on the head and thorax of many male Lamellicorns and Staphylinidae. A perfect

series can be formed from the bestprovided to the worstprovided or degenerate males. Although the

mandibles of the common stagbeetle, and probably of many other species, are used as efficient weapons for

fighting, it is doubtful whether their great size can thus be accounted for. We have seen that they are used by

the Lucanus elaphus of N. America for seizing the female. As they are so conspicuous and so elegantly

branched, and as owing to their great length they are not well adapted for pinching, the suspicion has crossed

my mind that they may in addition serve as an ornament, like the horns on the head and thorax of the various

species above described. The male Chiasognathus grantii of S. Chilea splendid beetle belonging to the

same familyhas enormously developed mandibles (Fig. 24); he is bold and pugnacious; when threatened

he faces round, opens his great jaws, and at the same time stridulates loudly. But the mandibles were not

Sexual selection, which implies the possession of considerable perceptive powers and of strong passions,

seems to have been more effective with the Lamellicorns than with any other family of beetles. With some

species the males are provided with weapons for fighting; some live in pairs and shew mutual affection; many

have the power of stridulating when excited; many are furnished with the most extraordinary horns,

apparently for the sake of ornament; and some, which are diurnal in their habits, are gorgeously coloured.

Lastly, several of the largest beetles in the world belong to this family, which was placed by Linnaeus and

Fabricius as the head of the Order. (72. Westwood, 'Modern Classification,' vol. i. p. 184.)

Beetles belonging to many and widely distinct families possess these organs. The sound thus produced can

sometimes be heard at the distance of several feet or even yards (73. Wollaston, 'On Certain Musical

Curculionidae,' 'Annals and Mag. of Nat. Hist.' vol. vi. 1860, p. 14.), but it is not comparable with that made

by the Orthoptera. The rasp generally consists of a narrow, slightlyraised surface, crossed by very fine,

parallel ribs, sometimes so fine as to cause iridescent colours, and having a very elegant appearance under the

microscope. In some cases, as with Typhoeus, minute, bristly or scalelike prominences, with which the

whole surrounding surface is covered in approximately parallel lines, could be traced passing into the ribs of

the rasp. The transition takes place by their becoming confluent and straight, and at the same time more

prominent and smooth. A hard ridge on an adjoining part of the body serves as the scraper for the rasp, but

this scraper in some cases has been specially modified for the purpose. It is rapidly moved across the rasp, or

[Fig.25. Necrophorus (from Landois). r. The two rasps. Lefthand figure, part of the rasp highly magnified.]

These organs are situated in widely different positions. In the carrion beetles (Necrophorus) two parallel

rasps (r, Fig. 25) stand on the dorsal surface of the fifth abdominal segment, each rasp (74. Landois,

'Zeitschrift fur wissenschaft Zoolog.' B. xvii. 1867, s. 127.) consisting of 126 to 140 fine ribs. These ribs are

scraped against the posterior margins of the elytra, a small portion of which projects beyond the general

outline. In many Crioceridae, and in Clythra 4punctata (one of the Chrysomelidae), and in some

Tenebrionidae, etc. (75. I am greatly indebted to Mr. G.R. Crotch for having sent me many prepared

specimens of various beetles belonging to these three families and to others, as well as for valuable

information. He believes that the power of stridulation in the Clythra has not been previously observed. I am

also much indebted to Mr. E.W. Janson, for information and specimens. I may add that my son, Mr. F.

Darwin, finds that Dermestes murinus stridulates, but he searched in vain for the apparatus. Scolytus has

lately been described by Dr. Chapman as a stridulator, in the 'Entomologist's Monthly Magazine,' vol. vi. p.

130.), the rasp is seated on the dorsal apex of the abdomen, on the pygidium or propygidium, and is scraped

in the same manner by the elytra. In Heterocerus, which belongs to another family, the rasps are placed on the

sides of the first abdominal segment, and are scraped by ridges on the femora. (76. Schiodte, translated, in

'Annals and Magazine of Natural History,' vol. xx. 1867, p. 37.) In certain Curculionidae and Carabidae (77.

Westring has described (Kroyer, 'Naturhist. Tidskrift,' B. ii. 1848 49, p. 334) the stridulating organs in these

two, as well as in other families. In the Carabidae I have examined Elaphrus uliginosus and Blethisa

multipunctata, sent to me by Mr. Crotch. In Blethisa the transverse ridges on the furrowed border of the

abdominal segment do not, as far as I could judge, come into play in scraping the rasps on the elytra.), the

parts are completely reversed in position, for the rasps are seated on the inferior surface of the elytra, near

their apices, or along their outer margins, and the edges of the abdominal segments serve as the scrapers. In

Pelobius Hermanni (one of Dytiscidae or waterbeetles) a strong ridge runs parallel and near to the sutural

margin of the elytra, and is crossed by ribs, coarse in the middle part, but becoming gradually finer at both

ends, especially at the upper end; when this insect is held under water or in the air, a stridulating noise is

produced by the extreme horny margin of the abdomen being scraped against the rasps. In a great number of

longhorned beetles (Longicornia) the organs are situated quite otherwise, the rasp being on the

mesothorax, which is rubbed against the prothorax; Landois counted 238 very fine ribs on the rasp of

[Fig.26. Hindleg of Geotrupes stercorarius (from Landois). r. Rasp. c. Coxa. f. Femur. t. Tibia. tr. Tarsi.]

Many Lamellicorns have the power of stridulating, and the organs differ greatly in position. Some species

stridulate very loudly, so that when Mr. F. Smith caught a Trox sabulosus, a gamekeeper, who stood by,

thought he had caught a mouse; but I failed to discover the proper organs in this beetle. In Geotrupes and

Typhoeus, a narrow ridge runs obliquely across (r, Fig. 26) the coxa of each hindleg (having in G.

stercorarius 84 ribs), which is scraped by a specially projecting part of one of the abdominal segments. In the

nearly allied Copris lunaris, an excessively narrow fine rasp runs along the sutural margin of the elytra, with

another short rasp near the basal outer margin; but in some other Coprini the rasp is seated, according to

Leconte (78. I am indebted to Mr. Walsh, of Illinois, for having sent me extracts from Leconte's 'Introduction

to Entomology,' pp. 101, 143.), on the dorsal surface of the abdomen. In Oryctes it is seated on the

propygidium; and, according to the same entomologist, in some other Dynastini, on the under surface of the

elytra. Lastly, Westring states that in Omaloplia brunnea the rasp is placed on the prosternum, and the

scraper on the metasternum, the parts thus occupying the under surface of the body, instead of the upper

We thus see that in the different coleopterous families the stridulating organs are wonderfully diversified in

position, but not much in structure. Within the same family some species are provided with these organs, and

others are destitute of them. This diversity is intelligible, if we suppose that originally various beetles made a

shuffling or hissing noise by the rubbing together of any hard and rough parts of their bodies, which

happened to be in contact; and that from the noise thus produced being in some way useful, the rough

surfaces were gradually developed into regular stridulating organs. Some beetles as they move, now produce,

either intentionally or unintentionally, a shuffling noise, without possessing any proper organs for the

purpose. Mr. Wallace informs me that the Euchirus longimanus (a Lamellicorn, with the anterior legs

wonderfully elongated in the male) "makes, whilst moving, a low hissing sound by the protrusion and

contraction of the abdomen; and when seized it produces a grating sound by rubbing its hindlegs against the

edges of the elytra." The hissing sound is clearly due to a narrow rasp running along the sutural margin of

each elytron; and I could likewise make the grating sound by rubbing the shagreened surface of the femur

against the granulated margin of the corresponding elytron; but I could not here detect any proper rasp; nor is

it likely that I could have overlooked it in so large an insect. After examining Cychrus, and reading what

Westring has written about this beetle, it seems very doubtful whether it possesses any true rasp, though it has

From the analogy of the Orthoptera and Homoptera, I expected to find the stridulating organs in the

Coleoptera differing according to sex; but Landois, who has carefully examined several species, observed no

such difference; nor did Westring; nor did Mr. G.R. Crotch in preparing the many specimens which he had

the kindness to send me. Any difference in these organs, if slight, would, however, be difficult to detect, on

account of their great variability. Thus, in the first pair of specimens of Necrophorus humator and of Pelobius

which I examined, the rasp was considerably larger in the male than in the female; but not so with succeeding

specimens. In Geotrupes stercorarius the rasp appeared to me thicker, opaquer, and more prominent in three

males than in the same number of females; in order, therefore, to discover whether the sexes differed in their

power of stridulating, my son, Mr. F. Darwin, collected fiftyseven living specimens, which he separated into

two lots, according as they made a greater or lesser noise, when held in the same manner. He then examined

all these specimens, and found that the males were very nearly in the same proportion to the females in both

the lots. Mr. F. Smith has kept alive numerous specimens of Monoynchus pseudacori (Curculionidae), and is

Nevertheless, the power of stridulating is certainly a sexual character in some few Coleoptera. Mr. Crotch

discovered that the males alone of two species of Heliopathes (Tenebrionidae) possess stridulating organs. I

examined five males of H. gibbus, and in all these there was a well developed rasp, partially divided into

two, on the dorsal surface of the terminal abdominal segment; whilst in the same number of females there

was not even a rudiment of the rasp, the membrane of this segment being transparent, and much thinner than

in the male. In H. cribratostriatus the male has a similar rasp, excepting that it is not partially divided into two

portions, and the female is completely destitute of this organ; the male in addition has on the apical margins

of the elytra, on each side of the suture, three or four short longitudinal ridges, which are crossed by

extremely fine ribs, parallel to and resembling those on the abdominal rasp; whether these ridges serve as an

independent rasp, or as a scraper for the abdominal rasp, I could not decide: the female exhibits no trace of

Again, in three species of the Lamellicorn genus Oryctes, we have a nearly parallel case. In the females of O.

gryphus and nasicornis the ribs on the rasp of the propygidium are less continuous and less distinct than in

the males; but the chief difference is that the whole upper surface of this segment, when held in the proper

light, is seen to be clothed with hairs, which are absent or are represented by excessively fine down in the

males. It should be noticed that in all Coleoptera the effective part of the rasp is destitute of hairs. In O.

senegalensis the difference between the sexes is more strongly marked, and this is best seen when the proper

abdominal segment is cleaned and viewed as a transparent object. In the female the whole surface is covered

with little separate crests, bearing spines; whilst in the male these crests in proceeding towards the apex,

become more and more confluent, regular, and naked; so that threefourths of the segment is covered with

extremely fine parallel ribs, which are quite absent in the female. In the females, however, of all three species

of Oryctes, a slight grating or stridulating sound is produced, when the abdomen of a softened specimen is

In the case of the Heliopathes and Oryctes there can hardly be a doubt that the males stridulate in order to call

or to excite the females; but with most beetles the stridulation apparently serves both sexes as a mutual call.

Beetles stridulate under various emotions, in the same manner as birds use their voices for many purposes

besides singing to their mates. The great Chiasognathus stridulates in anger or defiance; many species do the

same from distress or fear, if held so that they cannot escape; by striking the hollow stems of trees in the

Canary Islands, Messrs. Wollaston and Crotch were able to discover the presence of beetles belonging to the

genus Acalles by their stridulation. Lastly, the male Ateuchus stridulates to encourage the female in her work,

and from distress when she is removed. (79. M. P. de la Brulerie, as quoted in 'Journal of Travel,' A. Murray,

vol. i. 1868, p. 135.) Some naturalists believe that beetles make this noise to frighten away their enemies; but

I cannot think that a quadruped or bird, able to devour a large beetle, would be frightened by so slight a

sound. The belief that the stridulation serves as a sexual call is supported by the fact that deathticks

(Anobium tessellatum) are well known to answer each other's ticking, and, as I have myself observed, a

tapping noise artificially made. Mr. Doubleday also informs me that he has sometimes observed a female

ticking (80. According to Mr. Doubleday, "the noise is produced by the insect raising itself on its legs as high

as it can, and then striking its thorax five or six times, in rapid succession, against the substance upon which

it is sitting." For references on this subject see Landois, 'Zeitschrift fur wissen. Zoolog.' B. xvii. s. 131.

Olivier says (as quoted by Kirby and Spence, 'Introduction to Entomology,' vol. ii. p. 395) that the female of

Pimelia striata produces a rather loud sound by striking her abdomen against any hard substance, "and that

the male, obedient to this call, soon attends her, and they pair."), and in an hour or two afterwards has found

her united with a male, and on one occasion surrounded by several males. Finally, it is probable that the two

sexes of many kinds of beetles were at first enabled to find each other by the slight shuffling noise produced

by the rubbing together of the adjoining hard parts of their bodies; and that as those males or females which

made the greatest noise succeeded best in finding partners, rugosities on various parts of their bodies were

Courtship of butterfliesBattlesTicking noiseColours common to both sexes, or more brilliant in the

malesExamplesNot due to the direct action of the conditions of lifeColours adapted for

protectionColours of mothsDisplayPerceptive powers of the LepidopteraVariability Causes of

the difference in colour between the males and femalesMimicry, female butterflies more brilliantly

coloured than the malesBright colours of caterpillarsSummary and concluding remarks on the

In this great Order the most interesting points for us are the differences in colour between the sexes of the

same species, and between the distinct species of the same genus. Nearly the whole of the following chapter

will be devoted to this subject; but I will first make a few remarks on one or two other points. Several males

may often be seen pursuing and crowding round the same female. Their courtship appears to be a prolonged

affair, for I have frequently watched one or more males pirouetting round a female until I was tired, without

seeing the end of the courtship. Mr. A.G. Butler also informs me that he has several times watched a male

courting a female for a full quarter of an hour; but she pertinaciously refused him, and at last settled on the

Although butterflies are weak and fragile creatures, they are pugnacious, and an emperor butterfly (1.

Apatura Iris: 'The Entomologist's Weekly Intelligence,' 1859, p. 139. For the Bornean Butterflies, see C.

Collingwood, 'Rambles of a Naturalist,' 1868, p. 183.) has been captured with the tips of its wings broken

from a conflict with another male. Mr. Collingwood, in speaking of the frequent battles between the

butterflies of Borneo, says, "They whirl round each other with the greatest rapidity, and appear to be incited

The Ageronia feronia makes a noise like that produced by a toothed wheel passing under a spring catch, and

which can be heard at the distance of several yards: I noticed this sound at Rio de Janeiro, only when two of

these butterflies were chasing each other in an irregular course, so that it is probably made during the

courtship of the sexes. (2. See my 'Journal of Researches,' 1845, p. 33. Mr. Doubleday has detected ('Proc.

Ent. Soc.' March 3, 1845, p. 123) a peculiar membranous sac at the base of the front wings, which is probably

connected with the production of the sound. For the case of Thecophora, see 'Zoological Record,' 1869, p.

401. For Mr. Buchanan White's observations, the Scottish Naturalist, July 1872, p. 214.)

Some moths also produce sounds; for instance, the males Theocophora fovea. On two occasions Mr. F.

Buchanan White (3. 'The Scottish Naturalist,' July 1872, p. 213.) heard a sharp quick noise made by the male

of Hylophila prasinana, and which he believes to be produced, as in Cicada, by an elastic membrane,

furnished with a muscle. He quotes, also, Guenee, that Setina produces a sound like the ticking of a watch,

apparently by the aid of "two large tympaniform vesicles, situated in the pectoral region"; and these "are

much more developed in the male than in the female." Hence the soundproducing organs in the Lepidoptera

appear to stand in some relation with the sexual functions. I have not alluded to the wellknown noise made

by the Death's Head Sphinx, for it is generally heard soon after the moth has emerged from its cocoon.

Giard has always observed that the musky odour, which is emitted by two species of Sphinx moths, is

peculiar to the males (4. 'Zoological Record,' 1869, p. 347.); and in the higher classes we shall meet with

Every one must have admired the extreme beauty of many butterflies and of some moths; and it may be

asked, are their colours and diversified patterns the result of the direct action of the physical conditions to

which these insects have been exposed, without any benefit being thus derived? Or have successive variations

been accumulated and determined as a protection, or for some unknown purpose, or that one sex may be

attractive to the other? And, again, what is the meaning of the colours being widely different in the males and

females of certain species, and alike in the two sexes of other species of the same genus? Before attempting

With our beautiful English butterflies, the admiral, peacock, and painted lady (Vanessae), as well as many

others, the sexes are alike. This is also the case with the magnificent Heliconidae, and most of the Danaidae

in the tropics. But in certain other tropical groups, and in some of our English butterflies, as the purple

emperor, orangetip, etc. (Apatura Iris and Anthocharis cardamines), the sexes differ either greatly or slightly

in colour. No language suffices to describe the splendour of the males of some tropical species. Even within

the same genus we often find species presenting extraordinary differences between the sexes, whilst others

have their sexes closely alike. Thus in the South American genus Epicalia, Mr. Bates, to whom I am indebted

for most of the following facts, and for looking over this whole discussion, informs me that he knows twelve

species, the two sexes of which haunt the same stations (and this is not always the case with butterflies), and

which, therefore, cannot have been differently affected by external conditions. (5. See also Mr. Bates's paper

in 'Proc. Ent. Soc. of Philadelphia,' 1865, p. 206. Also Mr. Wallace on the same subject, in regard to

Diadema, in 'Transactions, Entomological Society of London,' 1869, p. 278.) In nine of these twelve species

the males rank amongst the most brilliant of all butterflies, and differ so greatly from the comparatively plain

females that they were formerly placed in distinct genera. The females of these nine species resemble each

other in their general type of coloration; and they likewise resemble both sexes of the species in several allied

genera found in various parts of the world. Hence we may infer that these nine species, and probably all the

others of the genus, are descended from an ancestral form which was coloured in nearly the same manner. In

the tenth species the female still retains the same general colouring, but the male resembles her, so that he is

coloured in a much less gaudy and contrasted manner than the males of the previous species. In the eleventh

and twelfth species, the females depart from the usual type, for they are gaily decorated almost like the males,

but in a somewhat less degree. Hence in these two latter species the bright colours of the males seem to have

been transferred to the females; whilst in the tenth species the male has either retained or recovered the plain

colours of the female, as well as of the parentform of the genus. The sexes in these three cases have thus

been rendered nearly alike, though in an opposite manner. In the allied genus Eubagis, both sexes of some of

the species are plaincoloured and nearly alike; whilst with the greater number the males are decorated with

beautiful metallic tints in a diversified manner, and differ much from their females. The females throughout

the genus retain the same general style of colouring, so that they resemble one another much more closely

In the genus Papilio, all the species of the Aeneas group are remarkable for their conspicuous and strongly

contrasted colours, and they illustrate the frequent tendency to gradation in the amount of difference between

the sexes. In a few species, for instance in P. ascanius, the males and females are alike; in others the males are

either a little brighter, or very much more superb than the females. The genus Junonia, allied to our Vanessae,

offers a nearly parallel case, for although the sexes of most of the species resemble each other, and are

destitute of rich colours, yet in certain species, as in J. oenone, the male is rather more brightcoloured than

the female, and in a few (for instance J. andremiaja) the male is so different from the female that he might be

Another striking case was pointed out to me in the British Museum by Mr. A. Butler, namely, one of the

tropical American Theclae, in which both sexes are nearly alike and wonderfully splendid; in another species

the male is coloured in a similarly gorgeous manner, whilst the whole upper surface of the female is of a dull

uniform brown. Our common little English blue butterflies of the genus Lycaena, illustrate the various

differences in colour between the sexes, almost as well, though not in so striking a manner, as the above

exotic genera. In Lycaena agestis both sexes have wings of a brown colour, bordered with small ocellated

orange spots, and are thus alike. In L. oegon the wings of the males are of a fine blue, bordered with black,

whilst those of the female are brown, with a similar border, closely resembling the wings of L. agestis. Lastly,

in L. arion both sexes are of a blue colour and are very like, though in the female the edges of the wings are

rather duskier, with the black spots plainer; and in a bright blue Indian species both sexes are still more alike.

I have given the foregoing details in order to shew, in the first place, that when the sexes of butterflies differ,

the male as a general rule is the more beautiful, and departs more from the usual type of colouring of the

group to which the species belongs. Hence in most groups the females of the several species resemble each

other much more closely than do the males. In some cases, however, to which I shall hereafter allude, the

females are coloured more splendidly than the males. In the second place, these details have been given to

bring clearly before the mind that within the same genus, the two sexes frequently present every gradation

from no difference in colour, to so great a difference that it was long before the two were placed by

entomologists in the same genus. In the third place, we have seen that when the sexes nearly resemble each

other, this appears due either to the male having transferred his colours to the female, or to the male having

retained, or perhaps recovered, the primordial colours of the group. It also deserves notice that in those

groups in which the sexes differ, the females usually somewhat resemble the males, so that when the males

are beautiful to an extraordinary degree, the females almost invariably exhibit some degree of beauty. From

the many cases of gradation in the amount of difference between the sexes, and from the prevalence of the

same general type of coloration throughout the whole of the same group, we may conclude that the causes

have generally been the same which have determined the brilliant colouring of the males alone of some

As so many gorgeous butterflies inhabit the tropics, it has often been supposed that they owe their colours to

the great heat and moisture of these zones; but Mr. Bates (6. 'The Naturalist on the Amazons,' vol. i. 1863, p.

19.) has shown by the comparison of various closelyallied groups of insects from the temperate and tropical

regions, that this view cannot be maintained; and the evidence becomes conclusive when brilliantly

coloured males and plaincoloured females of the same species inhabit the same district, feed on the same

food, and follow exactly the same habits of life. Even when the sexes resemble each other, we can hardly

believe that their brilliant and beautifullyarranged colours are the purposeless result of the nature of the

With animals of all kinds, whenever colour has been modified for some special purpose, this has been, as far

as we can judge, either for direct or indirect protection, or as an attraction between the sexes. With many

species of butterflies the upper surfaces of the wings are obscure; and this in all probability leads to their

escaping observation and danger. But butterflies would be particularly liable to be attacked by their enemies

when at rest; and most kinds whilst resting raise their wings vertically over their backs, so that the lower

surface alone is exposed to view. Hence it is this side which is often coloured so as to imitate the objects on

which these insects commonly rest. Dr. Rossler, I believe, first noticed the similarity of the closed wings of

certain Vanessae and other butterflies to the bark of trees. Many analogous and striking facts could be given.

The most interesting one is that recorded by Mr. Wallace (7. See the interesting article in the 'Westminster

Review,' July 1867, p. 10. A woodcut of the Kallima is given by Mr. Wallace in 'Hardwicke's Science

Gossip,' September 1867, p. 196.) of a common Indian and Sumatran butterfly (Kallima) which disappears

like magic when it settles on a bush; for it hides its head and antennae between its closed wings, which, in

form, colour and veining, cannot be distinguished from a withered leaf with its footstalk. In some other cases

the lower surfaces of the wings are brilliantly coloured, and yet are protective; thus in Thecla rubi the wings

when closed are of an emerald green, and resemble the young leaves of the bramble, on which in spring this

butterfly may often be seen seated. It is also remarkable that in very many species in which the sexes differ

greatly in colour on their upper surface, the lower surface is closely similar or identical in both sexes, and

Although the obscure tints both of the upper and under sides of many butterflies no doubt serve to conceal

them, yet we cannot extend this view to the brilliant and conspicuous colours on the upper surface of such

species as our admiral and peacock Vanessae, our white cabbagebutterflies (Pieris), or the great

swallowtail Papilio which haunts the open fensfor these butterflies are thus rendered visible to every

living creature. In these species both sexes are alike; but in the common brimstone butterfly (Gonepteryx

rhamni), the male is of an intense yellow, whilst the female is much paler; and in the orangetip (Anthocharis

cardamines) the males alone have their wings tipped with bright orange. Both the males and females in these

cases are conspicuous, and it is not credible that their difference in colour should stand in any relation to

ordinary protection. Prof. Weismann remarks (9. 'Einfluss der Isolirung auf die Artbildung,' 1872, p. 58.), that

the female of one of the Lycaenae expands her brown wings when she settles on the ground, and is then

almost invisible; the male, on the other hand, as if aware of the danger incurred from the bright blue of the

upper surface of his wings, rests with them closed; and this shows that the blue colour cannot be in any way

protective. Nevertheless, it is probable that conspicuous colours are indirectly beneficial to many species, as a

warning that they are unpalatable. For in certain other cases, beauty has been gained through the imitation of

other beautiful species, which inhabit the same district and enjoy an immunity from attack by being in some

way offensive to their enemies; but then we have to account for the beauty of the imitated species.

As Mr. Walsh has remarked to me, the females of our orangetip butterfly, above referred to, and of an

American species (Anth. genutia) probably shew us the primordial colours of the parentspecies of the genus;

for both sexes of four or five widelydistributed species are coloured in nearly the same manner. As in

several previous cases, we may here infer that it is the males of Anth. cardamines and genutia which have

departed from the usual type of the genus. In the Anth. sara from California, the orange tips to the wings

have been partially developed in the female; but they are paler than in the male, and slightly different in some

other respects. In an allied Indian form, the Iphias glaucippe, the orangetips are fully developed in both

sexes. In this Iphias, as pointed out to me by Mr. A. Butler, the under surface of the wings marvellously

resembles a pale coloured leaf; and in our English orangetip, the under surface resembles the flowerhead

of the wild parsley, on which the butterfly often rests at night. (10. See the interesting observations by T.W.

Wood, 'The Student,' Sept. 1868, p. 81.) The same reason which compels us to believe that the lower surfaces

have here been coloured for the sake of protection, leads us to deny that the wings have been tipped with

bright orange for the same purpose, especially when this character is confined to the males.

Most Moths rest motionless during the whole or greater part of the day with their wings depressed; and the

whole upper surface is often shaded and coloured in an admirable manner, as Mr. Wallace has remarked, for

escaping detection. The frontwings of the Bombycidae and Noctuidae (11. Mr. Wallace in 'Hardwicke's

Science Gossip,' September 1867, p. 193.), when at rest, generally overlap and conceal the hindwings; so

that the latter might be brightly coloured without much risk; and they are in fact often thus coloured. During

flight, moths would often be able to escape from their enemies; nevertheless, as the hindwings are then fully

exposed to view, their bright colours must generally have been acquired at some little risk. But the following

fact shews how cautious we ought to be in drawing conclusions on this head. The common Yellow

Underwings (Triphaena) often fly about during the day or early evening, and are then conspicuous from the

colour of their hindwings. It would naturally be thought that this would be a source of danger; but Mr. J.

Jenner Weir believes that it actually serves them as a means of escape, for birds strike at these brightly

coloured and fragile surfaces, instead of at the body. For instance, Mr. Weir turned into his aviary a vigorous

specimen of Triphaena pronuba, which was instantly pursued by a robin; but the bird's attention being caught

by the coloured wings, the moth was not captured until after about fifty attempts, and small portions of the

wings were repeatedly broken off. He tried the same experiment, in the open air, with a swallow and T.

fimbria; but the large size of this moth probably interfered with its capture. (12. See also, on this subject, Mr.

Weir's paper in 'Transactions, Entomological Society,' 1869, p. 23.) We are thus reminded of a statement

made by Mr. Wallace (13. 'Westminster Review,' July 1867, p. 16.), namely, that in the Brazilian forests and

Malayan islands, many common and highlydecorated butterflies are weak flyers, though furnished with a

broad expanse of wing; and they "are often captured with pierced and broken wings, as if they had been

seized by birds, from which they had escaped: if the wings had been much smaller in proportion to the body,

it seems probable that the insect would more frequently have been struck or pierced in a vital part, and thus

The bright colours of many butterflies and of some moths are specially arranged for display, so that they may

be readily seen. During the night colours are not visible, and there can be no doubt that the nocturnal moths,

taken as a body, are much less gaily decorated than butterflies, all of which are diurnal in their habits. But the

moths of certain families, such as the Zygaenidae, several Sphingidae, Uraniidae, some Arctiidae and

Saturniidae, fly about during the day or early evening, and many of these are extremely beautiful, being far

brighter coloured than the strictly nocturnal kinds. A few exceptional cases, however, of brightcoloured

nocturnal species have been recorded. (14. For instance, Lithosia; but Prof. Westwood ('Modern Class. of

Insects,' vol. ii. p. 390) seems surprised at this case. On the relative colours of diurnal and nocturnal

Lepidoptera, see ibid. pp. 333 and 392; also Harris, 'Treatise on the Insects of New England,' 1842, p. 315.)

There is evidence of another kind in regard to display. Butterflies, as before remarked, elevate their wings

when at rest, but whilst basking in the sunshine often alternately raise and depress them, thus exposing both

surfaces to full view; and although the lower surface is often coloured in an obscure manner as a protection,

yet in many species it is as highly decorated as the upper surface, and sometimes in a very different manner.

In some tropical species the lower surface is even more brilliantly coloured than the upper. (15. Such

differences between the upper and lower surfaces of the wings of several species of Papilio may be seen in

the beautiful plates to Mr. Wallace's 'Memoir on the Papilionidae of the Malayan Region,' in 'Transactions of

the Linnean Society,' vol. xxv. part i. 1865.) In the English fritillaries (Argynnis) the lower surface alone is

ornamented with shining silver. Nevertheless, as a general rule, the upper surface, which is probably more

fully exposed, is coloured more brightly and diversely than the lower. Hence the lower surface generally

affords to entomologists the more useful character for detecting the affinities of the various species. Fritz

Muller informs me that three species of Castnia are found near his house in S. Brazil: of two of them the

hindwings are obscure, and are always covered by the frontwings when these butterflies are at rest; but the

third species has black hindwings, beautifully spotted with red and white, and these are fully expanded and

If we now turn to the enormous group of moths, which, as I hear from Mr. Stainton, do not habitually expose

the under surface of their wings to full view, we find this side very rarely coloured with a brightness greater

than, or even equal to, that of the upper side. Some exceptions to the rule, either real or apparent, must be

noticed, as the case of Hypopyra. (16. See Mr. Wormald on this moth: 'Proceedings of the Entomological

Society,' March 2, 1868.) Mr. Trimen informs me that in Guenee's great work, three moths are figured, in

which the under surface is much the more brilliant. For instance, in the Australian Gastrophora the upper

surface of the forewing is pale greyishochreous, while the lower surface is magnificently ornamented by

an ocellus of cobaltblue, placed in the midst of a black mark, surrounded by orangeyellow, and this by

bluishwhite. But the habits of these three moths are unknown; so that no explanation can be given of their

unusual style of colouring. Mr. Trimen also informs me that the lower surface of the wings in certain other

Geometrae (17. See also an account of the S. American genus Erateina (one of the Geometrae) in

'Transactions, Ent. Soc.' new series, vol. v. pl. xv. and xvi.) and quadrifid Noctuae are either more variegated

or more brightlycoloured than the upper surface; but some of these species have the habit of "holding their

wings quite erect over their backs, retaining them in this position for a considerable time," and thus exposing

the under surface to view. Other species, when settled on the ground or herbage, now and then suddenly and

slightly lift up their wings. Hence the lower surface of the wings being brighter than the upper surface in

certain moths is not so anomalous as it at first appears. The Saturniidae include some of the most beautiful of

all moths, their wings being decorated, as in our British Emperor moth, with fine ocelli; and Mr. T.W. Wood

(18. 'Proc Ent. Soc. of London,' July 6, 1868, p. xxvii.) observes that they resemble butterflies in some of

their movements; "for instance, in the gentle waving up and down of the wings as if for display, which is

It is a singular fact that no British moths which are brilliantly coloured, and, as far as I can discover, hardly

any foreign species, differ much in colour according to sex; though this is the case with many brilliant

butterflies. The male, however, of one American moth, the Saturnia Io, is described as having its forewings

deep yellow, curiously marked with purplishred spots; whilst the wings of the female are purplebrown,

marked with grey lines. (19. Harris, 'Treatise,' etc., edited by Flint, 1862, p. 395.) The British moths which

differ sexually in colour are all brown, or of various dull yellow tints, or nearly white. In several species the

males are much darker than the females (20. For instance, I observe in my son's cabinet that the males are

darker than the females in the Lasiocampa quercus, Odonestis potatoria, Hypogymna dispar, Dasychira

pudibunda, and Cycnia mendica. In this latter species the difference in colour between the two sexes is

strongly marked; and Mr. Wallace informs me that we here have, as he believes, an instance of protective

mimicry confined to one sex, as will hereafter be more fully explained. The white female of the Cycnia

resembles the very common Spilosoma menthrasti, both sexes of which are white; and Mr. Stainton observed

that this latter moth was rejected with utter disgust by a whole brood of young turkeys, which were fond of

eating other moths; so that if the Cycnia was commonly mistaken by British birds for the Spilosoma, it would

escape being devoured, and its white deceptive colour would thus be highly beneficial.), and these belong to

groups which generally fly about during the afternoon. On the other hand, in many genera, as Mr. Stainton

informs me, the males have the hindwings whiter than those of the femaleof which fact Agrotis

exclamationis offers a good instance. In the Ghost Moth (Hepialus humuli) the difference is more strongly

marked; the males being white, and the females yellow with darker markings. (21. It is remarkable, that in the

Shetland Islands the male of this moth, instead of differing widely from the female, frequently resembles her

closely in colour (see Mr. MacLachlan, 'Transactions, Entomological Society,' vol. ii. 1866, p. 459). Mr. G.

Fraser suggests ('Nature,' April 1871, p. 489) that at the season of the year when the ghostmoth appears in

these northern islands, the whiteness of the males would not be needed to render them visible to the females

in the twilight night.) It is probable that in these cases the males are thus rendered more conspicuous, and

From the several foregoing facts it is impossible to admit that the brilliant colours of butterflies, and of some

few moths, have commonly been acquired for the sake of protection. We have seen that their colours and

elegant patterns are arranged and exhibited as if for display. Hence I am led to believe that the females prefer

or are most excited by the more brilliant males; for on any other supposition the males would, as far as we

can see, be ornamented to no purpose. We know that ants and certain Lamellicorn beetles are capable of

feeling an attachment for each other, and that ants recognise their fellows after an interval of several months.

Hence there is no abstract improbability in the Lepidoptera, which probably stand nearly or quite as high in

the scale as these insects, having sufficient mental capacity to admire bright colours. They certainly discover

flowers by colour. The Hummingbird Sphinx may often be seen to swoop down from a distance on a bunch

of flowers in the midst of green foliage; and I have been assured by two persons abroad, that these moths

repeatedly visit flowers painted on the walls of a room, and vainly endeavour to insert their proboscis into

them. Fritz Muller informs me that several kinds of butterflies in S. Brazil shew an unmistakable preference

for certain colours over others: he observed that they very often visited the brilliant red flowers of five or six

genera of plants, but never the white or yellow flowering species of the same and other genera, growing in the

same garden; and I have received other accounts to the same effect. As I hear from Mr. Doubleday, the

common white butterfly often flies down to a bit of paper on the ground, no doubt mistaking it for one of its

own species. Mr. Collingwood (22. 'Rambles of a Naturalist in the Chinese Seas,' 1868, p. 182.) in speaking

of the difficulty in collecting certain butterflies in the Malay Archipelago, states that "a dead specimen pinned

upon a conspicuous twig will often arrest an insect of the same species in its headlong flight, and bring it

The courtship of butterflies is, as before remarked, a prolonged affair. The males sometimes fight together in

rivalry; and many may be seen pursuing or crowding round the same female. Unless, then, the females prefer

one male to another, the pairing must be left to mere chance, and this does not appear probable. If, on the

other band, the females habitually, or even occasionally, prefer the more beautiful males, the colours of the

latter will have been rendered brighter by degrees, and will have been transmitted to both sexes or to one sex,

according to the law of inheritance which has prevailed. The process of sexual selection will have been much

facilitated, if the conclusion can be trusted, arrived at from various kinds of evidence in the supplement to the

ninth chapter; namely, that the males of many Lepidoptera, at least in the imago state, greatly exceed the

Some facts, however, are opposed to the belief that female butterflies prefer the more beautiful males; thus,

as I have been assured by several collectors, fresh females may frequently be seen paired with battered,

faded, or dingy males; but this is a circumstance which could hardly fail often to follow from the males

emerging from their cocoons earlier than the females. With moths of the family of the Bombycidae, the sexes

pair immediately after assuming the imago state; for they cannot feed, owing to the rudimentary condition of

their mouths. The females, as several entomologists have remarked to me, lie in an almost torpid state, and

appear not to evince the least choice in regard to their partners. This is the case with the common silkmoth

(B. mori), as I have been told by some continental and English breeders. Dr. Wallace, who has had great

experience in breeding Bombyx cynthia, is convinced that the females evince no choice or preference. He has

kept above 300 of these moths together, and has often found the most vigorous females mated with stunted

males. The reverse appears to occur seldom; for, as he believes, the more vigorous males pass over the

weakly females, and are attracted by those endowed with most vitality. Nevertheless, the Bombycidae,

though obscurelycoloured, are often beautiful to our eyes from their elegant and mottled shades.

I have as yet only referred to the species in which the males are brighter coloured than the females, and I have

attributed their beauty to the females for many generations having chosen and paired with the more attractive

males. But converse cases occur, though rarely, in which the females are more brilliant than the males; and

here, as I believe, the males have selected the more beautiful females, and have thus slowly added to their

beauty. We do not know why in various classes of animals the males of some few species have selected the

more beautiful females instead of having gladly accepted any female, as seems to be the general rule in the

animal kingdom: but if, contrary to what generally occurs with the Lepidoptera, the females were much more

numerous than the males, the latter would be likely to pick out the more beautiful females. Mr. Butler shewed

me several species of Callidryas in the British Museum, in some of which the females equalled, and in others

greatly surpassed the males in beauty; for the females alone have the borders of their wings suffused with

crimson and orange, and spotted with black. The plainer males of these species closely resemble each other,

shewing that here the females have been modified; whereas in those cases, where the males are the more

ornate, it is these which have been modified, the females remaining closely alike.

In England we have some analogous cases, though not so marked. The females alone of two species of

Thecla have a brightpurple or orange patch on their forewings. In Hipparchia the sexes do not differ much;

but it is the female of H. janira which has a conspicuous lightbrown patch on her wings; and the females of

some of the other species are brighter coloured than their males. Again, the females of Colias edusa and hyale

have "orange or yellow spots on the black marginal border, represented in the males only by thin streaks";

and in Pieris it is the females which "are ornamented with black spots on the forewings, and these are only

partially present in the males." Now the males of many butterflies are known to support the females during

their marriage flight; but in the species just named it is the females which support the males; so that the part

which the two sexes play is reversed, as is their relative beauty. Throughout the animal kingdom the males

commonly take the more active share in wooing, and their beauty seems to have been increased by the

females having accepted the more attractive individuals; but with these butterflies, the females take the more

active part in the final marriage ceremony, so that we may suppose that they likewise do so in the wooing;

and in this case we can understand how it is that they have been rendered the more beautiful. Mr. Meldola,

from whom the foregoing statements have been taken, says in conclusion: "Though I am not convinced of the

action of sexual selection in producing the colours of insects, it cannot be denied that these facts are strikingly

corroborative of Mr. Darwin's views." (23. 'Nature,' April 27, 1871, p. 508. Mr. Meldola quotes Donzel, in

'Soc. Ent. de France,' 1837, p. 77, on the flight of butterflies whilst pairing. See also Mr. G. Fraser, in

'Nature,' April 20, 1871, p. 489, on the sexual differences of several British butterflies.)

As sexual selection primarily depends on variability, a few words must be added on this subject. In respect to

colour there is no difficulty, for any number of highly variable Lepidoptera could be named. One good

instance will suffice. Mr. Bates shewed me a whole series of specimens of Papilio sesostris and P. childrenae;

in the latter the males varied much in the extent of the beautifully enamelled green patch on the forewings,

and in the size of the white mark, and of the splendid crimson stripe on the hindwings; so that there was a

great contrast amongst the males between the most and the least gaudy. The male of Papilio sesostris is much

less beautiful than of P. childrenae; and it likewise varies a little in the size of the green patch on the

forewings, and in the occasional appearance of the small crimson stripe on the hindwings, borrowed, as it

would seem, from its own female; for the females of this and of many other species in the Aeneas group

possess this crimson stripe. Hence between the brightest specimens of P. sesostris and the dullest of P.

childrenae, there was but a small interval; and it was evident that as far as mere variability is concerned, there

would be no difficulty in permanently increasing the beauty of either species by means of selection. The

variability is here almost confined to the male sex; but Mr. Wallace and Mr. Bates have shewn (24. Wallace

on the Papilionidae of the Malayan Region, in 'Transact. Linn. Soc.' vol. xxv. 1865, pp. 8, 36. A striking case

of a rare variety, strictly intermediate between two other wellmarked female varieties, is given by Mr.

Wallace. See also Mr. Bates, in 'Proc. Entomolog. Soc.' Nov. 19, 1866, p. xl.) that the females of some

species are extremely variable, the males being nearly constant. In a future chapter I shall have occasion to

shew that the beautiful eyelike spots, or ocelli, found on the wings of many Lepidoptera, are eminently

variable. I may here add that these ocelli offer a difficulty on the theory of sexual selection; for though

appearing to us so ornamental, they are never present in one sex and absent in the other, nor do they ever

differ much in the two sexes. (25. Mr. Bates was so kind as to lay this subject before the Entomological

Society, and I have received answers to this effect from several entomologists.) This fact is at present

inexplicable; but if it should hereafter be found that the formation of an ocellus is due to some change in the

tissues of the wings, for instance, occurring at a very early period of development, we might expect, from

what we know of the laws of inheritance, that it would be transmitted to both sexes, though arising and

On the whole, although many serious objections may be urged, it seems probable that most of the

brilliantlycoloured species of Lepidoptera owe their colours to sexual selection, excepting in certain cases,

presently to be mentioned, in which conspicuous colours have been gained through mimicry as a protection.

From the ardour of the male throughout the animal kingdom, he is generally willing to accept any female; and

it is the female which usually exerts a choice. Hence, if sexual selection has been efficient with the

Lepidoptera, the male, when the sexes differ, ought to be the more brilliantly coloured, and this undoubtedly

is the case. When both sexes are brilliantly coloured and resemble each other, the characters acquired by the

males appear to have been transmitted to both. We are led to this conclusion by cases, even within the same

genus, of gradation from an extraordinary amount of difference to identity in colour between the two sexes.

But it may be asked whether the difference in colour between the sexes may not be accounted for by other

means besides sexual selection. Thus the males and females of the same species of butterfly are in several

cases known (26. H.W. Bates, 'The Naturalist on the Amazons,' vol. ii. 1863, p. 228. A.R. Wallace, in

'Transactions, Linnean Society,' vol. xxv. 1865, p. 10.) to inhabit different stations, the former commonly

basking in the sunshine, the latter haunting gloomy forests. It is therefore possible that different conditions of

life may have acted directly on the two sexes; but this is not probable (27. On this whole subject see 'The

Variation of Animals and Plants under Domestication,' 1868, vol. ii. chap. xxiii.) as in the adult state they are

exposed to different conditions during a very short period; and the larvae of both are exposed to the same

conditions. Mr. Wallace believes that the difference between the sexes is due not so much to the males having

been modified, as to the females having in all or almost all cases acquired dull colours for the sake of

protection. It seems to me, on the contrary, far more probable that it is the males which have been chiefly

modified through sexual selection, the females having been comparatively little changed. We can thus

understand how it is that the females of allied species generally resemble one another so much more closely

than do the males. They thus shew us approximately the primordial colouring of the parentspecies of the

group to which they belong. They have, however, almost always been somewhat modified by the transfer to

them of some of the successive variations, through the accumulation of which the males were rendered

beautiful. But I do not wish to deny that the females alone of some species may have been specially modified

for protection. In most cases the males and females of distinct species will have been exposed during their

prolonged larval state to different conditions, and may have been thus affected; though with the males any

slight change of colour thus caused will generally have been masked by the brilliant tints gained through

sexual selection. When we treat of Birds, I shall have to discuss the whole question, as to how far the

differences in colour between the sexes are due to the males having been modified through sexual selection

for ornamental purposes, or to the females having been modified through natural selection for the sake of

In all the cases in which the more common form of equal inheritance by both sexes has prevailed, the

selection of brightcoloured males would tend to make the females brightcoloured; and the selection of

dullcoloured females would tend to make the males dull. If both processes were carried on simultaneously,

they would tend to counteract each other; and the final result would depend on whether a greater number of

females from being well protected by obscure colours, or a greater number of males by being

brightlycoloured and thus finding partners, succeeded in leaving more numerous offspring.

In order to account for the frequent transmission of characters to one sex alone, Mr. Wallace expresses his

belief that the more common form of equal inheritance by both sexes can be changed through natural

selection into inheritance by one sex alone, but in favour of this view I can discover no evidence. We know

from what occurs under domestication that new characters often appear, which from the first are transmitted

to one sex alone; and by the selection of such variations there would not be the slightest difficulty in giving

bright colours to the males alone, and at the same time or subsequently, dull colours to the females alone. In

this manner the females of some butterflies and moths have, it is probable, been rendered inconspicuous for

I am, however, unwilling without distinct evidence to admit that two complex processes of selection, each

requiring the transference of new characters to one sex alone, have been carried on with a multitude of

species,that the males have been rendered more brilliant by beating their rivals, and the females more

dullcoloured by having escaped from their enemies. The male, for instance, of the common brimstone

butterfly (Gonepteryx), is of a far more intense yellow than the female, though she is equally conspicuous;

and it does not seem probable that she specially acquired her pale tints as a protection, though it is probable

that the male acquired his bright colours as a sexual attraction. The female of Anthocharis cardamines does

not possess the beautiful orange wingtips of the male; consequently she closely resembles the white

butterflies (Pieris) so common in our gardens; but we have no evidence that this resemblance is beneficial to

her. As, on the other hand, she resembles both sexes of several other species of the genus inhabiting various

quarters of the world, it is probable that she has simply retained to a large extent her primordial colours.

Finally, as we have seen, various considerations lead to the conclusion that with the greater number of

brilliantlycoloured Lepidoptera it is the male which has been chiefly modified through sexual selection; the

amount of difference between the sexes mostly depending on the form of inheritance which has prevailed.

Inheritance is governed by so many unknown laws or conditions, that it seems to us to act in a capricious

manner (28. The 'Variation of Animals and Plants under Domestication,' vol. ii. chap. xii. p. 17.); and we can

thus, to a certain extent, understand how it is that with closely allied species the sexes either differ to an

astonishing degree, or are identical in colour. As all the successive steps in the process of variation are

necessarily transmitted through the female, a greater or less number of such steps might readily become

developed in her; and thus we can understand the frequent gradations from an extreme difference to none at

all between the sexes of allied species. These cases of gradation, it may be added, are much too common to

favour the supposition that we here see females actually undergoing the process of transition and losing their

brightness for the sake of protection; for we have every reason to conclude that at any one time the greater

This principle was first made clear in an admirable paper by Mr. Bates (29. 'Transact. Linn. Soc.' vol. xxiii.

1862, p. 495.), who thus threw a flood of light on many obscure problems. It had previously been observed

that certain butterflies in S. America belonging to quite distinct families, resembled the Heliconidae so

closely in every stripe and shade of colour, that they could not be distinguished save by an experienced

entomologist. As the Heliconidae are coloured in their usual manner, whilst the others depart from the usual

colouring of the groups to which they belong, it is clear that the latter are the imitators, and the Heliconidae

the imitated. Mr. Bates further observed that the imitating species are comparatively rare, whilst the imitated

abound, and that the two sets live mingled together. From the fact of the Heliconidae being conspicuous and

beautiful insects, yet so numerous in individuals and species, he concluded that they must be protected from

the attacks of enemies by some secretion or odour; and this conclusion has now been amply confirmed (30.

'Proc. Entomological Soc.' Dec. 3, 1866, p. xlv.), especially by Mr. Belt. Hence Mr. Bates inferred that the

butterflies which imitate the protected species have acquired their present marvellously deceptive appearance

through variation and natural selection, in order to be mistaken for the protected kinds, and thus to escape

being devoured. No explanation is here attempted of the brilliant colours of the imitated, but only of the

imitating butterflies. We must account for the colours of the former in the same general manner, as in the

cases previously discussed in this chapter. Since the publication of Mr. Bates' paper, similar and equally

striking facts have been observed by Mr. Wallace in the Malayan region, by Mr. Trimen in South Africa, and

by Mr. Riley in the United States. (31. Wallace, 'Transact. Linn. Soc.' vol. xxv. 1865 p. i.; also, 'Transact. Ent.

Soc.' vol. iv. (3rd series), 1867, p. 301. Trimen, 'Linn. Transact.' vol. xxvi. 1869, p. 497. Riley, 'Third Annual

Report on the Noxious Insects of Missouri,' 1871, pp. 163168. This latter essay is valuable, as Mr. Riley

here discusses all the objections which have been raised against Mr. Bates's theory.)

As some writers have felt much difficulty in understanding how the first steps in the process of mimicry

could have been effected through natural selection, it may be well to remark that the process probably

commenced long ago between forms not widely dissimilar in colour. In this case even a slight variation

would be beneficial, if it rendered the one species more like the other; and afterwards the imitated species

might be modified to an extreme degree through sexual selection or other means, and if the changes were

gradual, the imitators might easily be led along the same track, until they differed to an equally extreme

degree from their original condition; and they would thus ultimately assume an appearance or colouring

wholly unlike that of the other members of the group to which they belonged. It should also be remembered

that many species of Lepidoptera are liable to considerable and abrupt variations in colour. A few instances

have been given in this chapter; and many more may be found in the papers of Mr. Bates and Mr. Wallace.

With several species the sexes are alike, and imitate the two sexes of another species. But Mr. Trimen gives,

in the paper already referred to, three cases in which the sexes of the imitated form differ from each other in

colour, and the sexes of the imitating form differ in a like manner. Several cases have also been recorded

where the females alone imitate brilliantlycoloured and protected species, the males retaining "the normal

aspect of their immediate congeners." It is here obvious that the successive variations by which the female

has been modified have been transmitted to her alone. It is, however, probable that some of the many

successive variations would have been transmitted to, and developed in, the males had not such males been

eliminated by being thus rendered less attractive to the females; so that only those variations were preserved

which were from the first strictly limited in their transmission to the female sex. We have a partial illustration

of these remarks in a statement by Mr. Belt (32. 'The Naturalist in Nicaragua,' 1874, p. 385.); that the males

of some of the Leptalides, which imitate protected species, still retain in a concealed manner some of their

original characters. Thus in the males "the upper half of the lower wing is of a pure white, whilst all the rest

of the wings is barred and spotted with black, red and yellow, like the species they mimic. The females have

not this white patch, and the males usually conceal it by covering it with the upper wing, so that I cannot

imagine its being of any other use to them than as an attraction in courtship, when they exhibit it to the

females, and thus gratify their deepseated preference for the normal colour of the Order to which the

Whilst reflecting on the beauty of many butterflies, it occurred to me that some caterpillars were splendidly

coloured; and as sexual selection could not possibly have here acted, it appeared rash to attribute the beauty

of the mature insect to this agency, unless the bright colours of their larvae could be somehow explained. In

the first place, it may be observed that the colours of caterpillars do not stand in any close correlation with

those of the mature insect. Secondly, their bright colours do not serve in any ordinary manner as a protection.

Mr. Bates informs me, as an instance of this, that the most conspicuous caterpillar which he ever beheld (that

of a Sphinx) lived on the large green leaves of a tree on the open llanos of South America; it was about four

inches in length, transversely banded with black and yellow, and with its head, legs, and tail of a bright red.

Hence it caught the eye of any one who passed by, even at the distance of many yards, and no doubt that of

I then applied to Mr. Wallace, who has an innate genius for solving difficulties. After some consideration he

replied: "Most caterpillars require protection, as may be inferred from some kinds being furnished with spines

or irritating hairs, and from many being coloured green like the leaves on which they feed, or being curiously

like the twigs of the trees on which they live." Another instance of protection, furnished me by Mr. J. Mansel

Weale, may be added, namely, that there is a caterpillar of a moth which lives on the mimosas in South

Africa, and fabricates for itself a case quite indistinguishable from the surrounding thorns. From such

considerations Mr. Wallace thought it probable that conspicuously coloured caterpillars were protected by

having a nauseous taste; but as their skin is extremely tender, and as their intestines readily protrude from a

wound, a slight peck from the beak of a bird would be as fatal to them as if they had been devoured. Hence,

as Mr. Wallace remarks, "distastefulness alone would be insufficient to protect a caterpillar unless some

outward sign indicated to its wouldbe destroyer that its prey was a disgusting morsel." Under these

circumstances it would be highly advantageous to a caterpillar to be instantaneously and certainly recognised

as unpalatable by all birds and other animals. Thus the most gaudy colours would be serviceable, and might

have been gained by variation and the survival of the most easily recognised individuals.

This hypothesis appears at first sight very bold, but when it was brought before the Entomological Society

(33. 'Proceedings, Entomological Society,' Dec. 3, 1866, p. xlv. and March 4, 1867, p. lxxx.) it was supported

by various statements; and Mr. J. Jenner Weir, who keeps a large number of birds in an aviary, informs me

that he has made many trials, and finds no exception to the rule, that all caterpillars of nocturnal and retiring

habits with smooth skins, all of a green colour, and all which imitate twigs, are greedily devoured by his

birds. The hairy and spinose kinds are invariably rejected, as were four conspicuouslycoloured species.

When the birds rejected a caterpillar, they plainly shewed, by shaking their heads, and cleansing their beaks,

that they were disgusted by the taste. (34. See Mr. J. Jenner Weir's paper on Insects and Insectivorous Birds,

in 'Transact. Ent. Soc.' 1869, p. 21; also Mr. Butler's paper, ibid. p. 27. Mr. Riley has given analogous facts in

the 'Third Annual Report on the Noxious Insects of Missouri,' 1871, p. 148. Some opposed cases are,

however, given by Dr. Wallace and M. H. d'Orville; see 'Zoological Record,' 1869, p. 349.) Three

conspicuous kinds of caterpillars and moths were also given to some lizards and frogs, by Mr. A. Butler, and

were rejected, though other kinds were eagerly eaten. Thus the probability of Mr. Wallace's view is

confirmed, namely, that certain caterpillars have been made conspicuous for their own good, so as to be

easily recognised by their enemies, on nearly the same principle that poisons are sold in coloured bottles by

druggists for the good of man. We cannot, however, at present thus explain the elegant diversity in the

colours of many caterpillars; but any species which had at some former period acquired a dull, mottled, or

striped appearance, either in imitation of surrounding objects, or from the direct action of climate, etc., almost

certainly would not become uniform in colour, when its tints were rendered intense and bright; for in order to

make a caterpillar merely conspicuous, there would be no selection in any definite direction.

Looking back to the several Orders, we see that the sexes often differ in various characters, the meaning of

which is not in the least understood. The sexes, also, often differ in their organs of sense and means of

locomotion, so that the males may quickly discover and reach the females. They differ still oftener in the

males possessing diversified contrivances for retaining the females when found. We are, however, here

In almost all the Orders, the males of some species, even of weak and delicate kinds, are known to be highly

pugnacious; and some few are furnished with special weapons for fighting with their rivals. But the law of

battle does not prevail nearly so widely with insects as with the higher animals. Hence it probably arises, that

it is in only a few cases that the males have been rendered larger and stronger than the females. On the

contrary, they are usually smaller, so that they may be developed within a shorter time, to be ready in large

In two families of the Homoptera and in three of the Orthoptera, the males alone possess soundproducing

organs in an efficient state. These are used incessantly during the breedingseason, not only for calling the

females, but apparently for charming or exciting them in rivalry with other males. No one who admits the

agency of selection of any kind, will, after reading the above discussion, dispute that these musical

instruments have been acquired through sexual selection. In four other Orders the members of one sex, or

more commonly of both sexes, are provided with organs for producing various sounds, which apparently

serve merely as callnotes. When both sexes are thus provided, the individuals which were able to make the

loudest or most continuous noise would gain partners before those which were less noisy, so that their organs

have probably been gained through sexual selection. It is instructive to reflect on the wonderful diversity of

the means for producing sound, possessed by the males alone, or by both sexes, in no less than six Orders.

We thus learn how effectual sexual selection has been in leading to modifications which sometimes, as with

From the reasons assigned in the last chapter, it is probable that the great horns possessed by the males of

many Lamellicorn, and some other beetles, have been acquired as ornaments. From the small size of insects,

we are apt to undervalue their appearance. If we could imagine a male Chalcosoma (Fig. 16), with its

polished bronzed coat of mail, and its vast complex horns, magnified to the size of a horse, or even of a dog,

The colouring of insects is a complex and obscure subject. When the male differs slightly from the female,

and neither are brilliantlycoloured, it is probable that the sexes have varied in a slightly different manner,

and that the variations have been transmitted by each sex to the same without any benefit or evil thus

accruing. When the male is brilliantlycoloured and differs conspicuously from the female, as with some

dragonflies and many butterflies, it is probable that he owes his colours to sexual selection; whilst the

female has retained a primordial or very ancient type of colouring, slightly modified by the agencies before

explained. But in some cases the female has apparently been made obscure by variations transmitted to her

alone, as a means of direct protection; and it is almost certain that she has sometimes been made brilliant, so

as to imitate other protected species inhabiting the same district. When the sexes resemble each other and

both are obscurely coloured, there is no doubt that they have been in a multitude of cases so coloured for the

sake of protection. So it is in some instances when both are brightlycoloured, for they thus imitate protected

species, or resemble surrounding objects such as flowers; or they give notice to their enemies that they are

unpalatable. In other cases in which the sexes resemble each other and are both brilliant, especially when the

colours are arranged for display, we may conclude that they have been gained by the male sex as an

attraction, and have been transferred to the female. We are more especially led to this conclusion whenever

the same type of coloration prevails throughout a whole group, and we find that the males of some species

differ widely in colour from the females, whilst others differ slightly or not at all with intermediate gradations

In the same manner as bright colours have often been partially transferred from the males to the females, so it

has been with the extraordinary horns of many Lamellicorn and some other beetles. So again, the

soundproducing organs proper to the males of the Homoptera and Orthoptera have generally been

transferred in a rudimentary, or even in a nearly perfect condition, to the females; yet not sufficiently perfect

to be of any use. It is also an interesting fact, as bearing on sexual selection, that the stridulating organs of

certain male Orthoptera are not fully developed until the last moult; and that the colours of certain male

dragonflies are not fully developed until some little time after their emergence from the pupal state, and

Sexual selection implies that the more attractive individuals are preferred by the opposite sex; and as with

insects, when the sexes differ, it is the male which, with some rare exceptions, is the more ornamented, and

departs more from the type to which the species belongs;and as it is the male which searches eagerly for

the female, we must suppose that the females habitually or occasionally prefer the more beautiful males, and

that these have thus acquired their beauty. That the females in most or all the Orders would have the power of

rejecting any particular male, is probable from the many singular contrivances possessed by the males, such

as great jaws, adhesive cushions, spines, elongated legs, etc., for seizing the female; for these contrivances

show that there is some difficulty in the act, so that her concurrence would seem necessary. Judging from

what we know of the perceptive powers and affections of various insects, there is no antecedent improbability

in sexual selection having come largely into play; but we have as yet no direct evidence on this head, and

some facts are opposed to the belief. Nevertheless, when we see many males pursuing the same female, we

can hardly believe that the pairing is left to blind chancethat the female exerts no choice, and is not

influenced by the gorgeous colours or other ornaments with which the male is decorated.

If we admit that the females of the Homoptera and Orthoptera appreciate the musical tones of their male

partners, and that the various instruments have been perfected through sexual selection, there is little

improbability in the females of other insects appreciating beauty in form or colour, and consequently in such

characters having been thus gained by the males. But from the circumstance of colour being so variable, and

from its having been so often modified for the sake of protection, it is difficult to decide in how large a

proportion of cases sexual selection has played a part. This is more especially difficult in those Orders, such

as Orthoptera, Hymenoptera, and Coleoptera, in which the two sexes rarely differ much in colour; for we are

then left to mere analogy. With the Coleoptera, however, as before remarked, it is in the great Lamellicorn

group, placed by some authors at the head of the Order, and in which we sometimes see a mutual attachment

between the sexes, that we find the males of some species possessing weapons for sexual strife, others

furnished with wonderful horns, many with stridulating organs, and others ornamented with splendid metallic

tints. Hence it seems probable that all these characters have been gained through the same means, namely

sexual selection. With butterflies we have the best evidence, as the males sometimes take pains to display

their beautiful colours; and we cannot believe that they would act thus, unless the display was of use to them

When we treat of Birds, we shall see that they present in their secondary sexual characters the closest analogy

with insects. Thus, many male birds are highly pugnacious, and some are furnished with special weapons for

fighting with their rivals. They possess organs which are used during the breedingseason for producing

vocal and instrumental music. They are frequently ornamented with combs, horns, wattles and plumes of the

most diversified kinds, and are decorated with beautiful colours, all evidently for the sake of display. We

shall find that, as with insects, both sexes in certain groups are equally beautiful, and are equally provided

with ornaments which are usually confined to the male sex. In other groups both sexes are equally

plaincoloured and unornamented. Lastly, in some few anomalous cases, the females are more beautiful than

the males. We shall often find, in the same group of birds, every gradation from no difference between the

sexes, to an extreme difference. We shall see that female birds, like female insects, often possess more or less

plain traces or rudiments of characters which properly belong to the males and are of use only to them. The

analogy, indeed, in all these respects between birds and insects is curiously close. Whatever explanation

applies to the one class probably applies to the other; and this explanation, as we shall hereafter attempt to

FISHES: Courtship and battles of the malesLarger size of the females Males, bright colours and

ornamental appendages; other strange characters Colours and appendages acquired by the males during the

breedingseason aloneFishes with both sexes brilliantly colouredProtective coloursThe less

conspicuous colours of the female cannot be accounted for on the principle of protectionMale fishes

REPTILES: CheloniansCrocodilesSnakes, colours in some cases protectiveLizards, battles

ofOrnamental appendagesStrange differences in structure between the sexesColoursSexual

We have now arrived at the great subkingdom of the Vertebrata, and will commence with the lowest class,

that of fishes. The males of Plagiostomous fishes (sharks, rays) and of Chimaeroid fishes are provided with

claspers which serve to retain the female, like the various structures possessed by many of the lower animals.

Besides the claspers, the males of many rays have clusters of strong sharp spines on their heads, and several

rows along "the upper outer surface of their pectoral fins." These are present in the males of some species,

which have other parts of their bodies smooth. They are only temporarily developed during the

breedingseason; and Dr. Gunther suspects that they are brought into action as prehensile organs by the

doubling inwards and downwards of the two sides of the body. It is a remarkable fact that the females and not

the males of some species, as of Raia clavata, have their backs studded with large hookformed spines. (1.

Yarrell's 'Hist. of British Fishes,' vol. ii. 1836, pp 417, 425, 436. Dr. Gunther informs me that the spines in R.

The males alone of the capelin (Mallotus villosus, one of Salmonidae), are provided with a ridge of

closelyset, brushlike scales, by the aid of which two males, one on each side, hold the female, whilst she

runs with great swiftness on the sandy beach, and there deposits her spawn. (2. The 'American Naturalist,'

April 1871, p. 119.) The widely distinct Monacanthus scopas presents a somewhat analogous structure. The

male, as Dr. Gunther informs me, has a cluster of stiff, straight spines, like those of a comb, on the sides of

the tail; and these in a specimen six inches long were nearly one and a half inches in length; the female has in

the same place a cluster of bristles, which may be compared with those of a toothbrush. In another species,

M. peronii, the male has a brush like that possessed by the female of the last species, whilst the sides of the

tail in the female are smooth. In some other species of the same genus the tail can be perceived to be a little

roughened in the male and perfectly smooth in the female; and lastly in others, both sexes have smooth sides.

The males of many fish fight for the possession of the females. Thus the male stickleback (Gasterosteus

leiurus) has been described as "mad with delight," when the female comes out of her hidingplace and

surveys the nest which he has made for her. "He darts round her in every direction, then to his accumulated

materials for the nest, then back again in an instant; and as she does not advance he endeavours to push her

with his snout, and then tries to pull her by the tail and sidespine to the nest." (3. See Mr. R. Warington's

interesting articles in 'Annals and Magazine of Natural History,' October 1852, and November 1855.) The

males are said to be polygamists (4. Noel Humphreys, 'River Gardens,' 1857.); they are extraordinarily bold

and pugnacious, whilst "the females are quite pacific." Their battles are at times desperate; "for these puny

combatants fasten tight on each other for several seconds, tumbling over and over again until their strength

appears completely exhausted." With the rough tailed stickleback (G. trachurus) the males whilst fighting

swim round and round each other, biting and endeavouring to pierce each other with their raised lateral

spines. The same writer adds (5. Loudon's 'Magazine of Natural History,' vol. iii. 1830, p. 331.), "the bite of

these little furies is very severe. They also use their lateral spines with such fatal effect, that I have seen one

during a battle absolutely rip his opponent quite open, so that he sank to the bottom and died." When a fish is

conquered, "his gallant bearing forsakes him; his gay colours fade away; and he hides his disgrace among his

peaceable companions, but is for some time the constant object of his conqueror's persecution."

The male salmon is as pugnacious as the little stickleback; and so is the male trout, as I hear from Dr.

Gunther. Mr. Shaw saw a violent contest between two male salmon which lasted the whole day; and Mr. R.

Buist, Superintendent of Fisheries, informs me that he has often watched from the bridge at Perth the males

driving away their rivals, whilst the females were spawning. The males "are constantly fighting and tearing

each other on the spawningbeds, and many so injure each other as to cause the death of numbers, many

being seen swimming near the banks of the river in a state of exhaustion, and apparently in a dying state." (6.

The 'Field,' June 29, 1867. For Mr. Shaw's Statement, see 'Edinburgh Review,' 1843. Another experienced

observer (Scrope's 'Days of Salmon Fishing,' p. 60) remarks that like the stag, the male would, if he could,

keep all other males away.) Mr. Buist informs me, that in June 1868, the keeper of the Stormontfield

breedingponds visited the northern Tyne and found about 300 dead salmon, all of which with one exception

[Fig. 27. Head of male common salmon (Salmo salar) during the breeding season. [This drawing, as well as

all the others in the present chapter, have been executed by the wellknown artist, Mr. G. Ford, from

specimens in the British Museum, under the kind superintendence of Dr. Gunther.]

The most curious point about the male salmon is that during the breeding season, besides a slight change in

colour, "the lower jaw elongates, and a cartilaginous projection turns upwards from the point, which, when

the jaws are closed, occupies a deep cavity between the intermaxillary bones of the upper jaw." (7. Yarrell,

'History of British Fishes,' vol. ii. 1836, p. 10.) (Figs. 27 and 28.) In our salmon this change of structure lasts

only during the breedingseason; but in the Salmo lycaodon of N.W. America the change, as Mr. J.K. Lord

(8. 'The Naturalist in Vancouver's Island,' vol. i. 1866, p. 54.) believes, is permanent, and best marked in the

older males which have previously ascended the rivers. In these old males the jaw becomes developed into an

immense hooklike projection, and the teeth grow into regular fangs, often more than half an inch in length.

With the European salmon, according to Mr. Lloyd (9. 'Scandinavian Adventures,' vol. i. 1854, pp. 100,

104.), the temporary hooklike structure serves to strengthen and protect the jaws, when one male charges

another with wonderful violence; but the greatly developed teeth of the male American salmon may be

compared with the tusks of many male mammals, and they indicate an offensive rather than a protective

The salmon is not the only fish in which the teeth differ in the two sexes; as this is the case with many rays.

In the thornback (Raia clavata) the adult male has sharp, pointed teeth, directed backwards, whilst those of

the female are broad and flat, and form a pavement; so that these teeth differ in the two sexes of the same

species more than is usual in distinct genera of the same family. The teeth of the male become sharp only

when he is adult: whilst young they are broad and flat like those of the female. As so frequently occurs with

secondary sexual characters, both sexes of some species of rays (for instance R. batis), when adult, possess

sharp pointed teeth; and here a character, proper to and primarily gained by the male, appears to have been

transmitted to the offspring of both sexes. The teeth are likewise pointed in both sexes of R. maculata, but

only when quite adult; the males acquiring them at an earlier age than the females. We shall hereafter meet

with analogous cases in certain birds, in which the male acquires the plumage common to both sexes when

adult, at a somewhat earlier age than does the female. With other species of rays the males even when old

never possess sharp teeth, and consequently the adults of both sexes are provided with broad, flat teeth like

those of the young, and like those of the mature females of the abovementioned species. (10. See Yarrell's

account of the rays in his 'History of British Fishes,' vol. ii. 1836, p. 416, with an excellent figure, and pp.

422, 432.) As the rays are bold, strong and voracious fish, we may suspect that the males require their sharp

teeth for fighting with their rivals; but as they possess many parts modified and adapted for the prehension of

In regard to size, M. Carbonnier (11. As quoted in 'The Farmer,' 1868, p. 369.) maintains that the female of

almost all fishes is larger than the male; and Dr. Gunther does not know of a single instance in which the

male is actually larger than the female. With some Cyprinodonts the male is not even half as large. As in

many kinds of fishes the males habitually fight together, it is surprising that they have not generally become

larger and stronger than the females through the effects of sexual selection. The males suffer from their small

size, for according to M. Carbonnier, they are liable to be devoured by the females of their own species when

carnivorous, and no doubt by other species. Increased size must be in some manner of more importance to the

females, than strength and size are to the males for fighting with other males; and this perhaps is to allow of

[Fig. 29. Callionymus lyra. Upper figure, male; lower figure, female. N.B. The lower figure is more reduced

In many species the male alone is ornamented with bright colours; or these are much brighter in the male than

the female. The male, also, is sometimes provided with appendages which appear to be of no more use to him

for the ordinary purposes of life, than are the tail feathers to the peacock. I am indebted for most of the

following facts to the kindness of Dr. Gunther. There is reason to suspect that many tropical fishes differ

sexually in colour and structure; and there are some striking cases with our British fishes. The male

Callionymus lyra has been called the gemmeous dragonet "from its brilliant gemlike colours." When fresh

caught from the sea the body is yellow of various shades, striped and spotted with vivid blue on the head; the

dorsal fins are pale brown with dark longitudinal bands; the ventral, caudal, and anal fins being bluishblack.

The female, or sordid dragonet, was considered by Linnaeus, and by many subsequent naturalists, as a

distinct species; it is of a dingy reddishbrown, with the dorsal fin brown and the other fins white. The sexes

differ also in the proportional size of the head and mouth, and in the position of the eyes (12. I have drawn up

this description from Yarrell's 'British Fishes,' vol. i. 1836, pp. 261 and 266.); but the most striking difference

is the extraordinary elongation in the male (Fig. 29) of the dorsal fin. Mr. W. Saville Kent remarks that this

"singular appendage appears from my observations of the species in confinement, to be subservient to the

same end as the wattles, crests, and other abnormal adjuncts of the male in gallinaceous birds, for the purpose

of fascinating their mates." (13. 'Nature,' July 1873, p. 264.) The young males resemble the adult females in

structure and colour. Throughout the genus Callionymus (14. 'Catalogue of Acanth. Fishes in the British

Museum,' by Dr. Gunther, 1861, pp. 138 151.), the male is generally much more brightly spotted than the

female, and in several species, not only the dorsal, but the anal fin is much elongated in the males.

The male of the Cottus scorpius, or seascorpion, is slenderer and smaller than the female. There is also a

great difference in colour between them. It is difficult, as Mr. Lloyd (15. 'Game Birds of Sweden,' etc., 1867,

p. 466.) remarks, "for any one, who has not seen this fish during the spawningseason, when its hues are

brightest, to conceive the admixture of brilliant colours with which it, in other respects so illfavoured, is at

that time adorned." Both sexes of the Labrus mixtus, although very different in colour, are beautiful; the male

being orange with bright blue stripes, and the female bright red with some black spots on the back.

In the very distinct family of the Cyprinodontidaeinhabitants of the fresh waters of foreign landsthe

sexes sometimes differ much in various characters. In the male of the Mollienesia petenensis (16. With

respect to this and the following species I am indebted to Dr. Gunther for information: see also his paper on

the 'Fishes of Central America,' in 'Transact. Zoological Soc.' vol. vi. 1868, p. 485.), the dorsal fin is greatly

developed and is marked with a row of large, round, ocellated, brightcoloured spots; whilst the same fin in

the female is smaller, of a different shape, and marked only with irregularly curved brown spots. In the male

the basal margin of the anal fin is also a little produced and dark coloured. In the male of an allied form, the

Xiphophorus Hellerii (Fig. 30), the inferior margin of the caudal fin is developed into a long filament, which,

as I hear from Dr. Gunther, is striped with bright colours. This filament does not contain any muscles, and

apparently cannot be of any direct use to the fish. As in the case of the Callionymus, the males whilst young

resemble the adult females in colour and structure. Sexual differences such as these may be strictly compared

with those which are so frequent with gallinaceous birds. (17. Dr. Gunther makes this remark; 'Catalogue of

[Fig.31. Plecostomus barbatus. Upper figure, head of male; lower figure, female.]

In a siluroid fish, inhabiting the fresh waters of South America, the Plecostomus barbatus (18. See Dr.

Gunther on this genus, in 'Proceedings of the Zoological Society,' 1868, p. 232.) (Fig. 31), the male has its

mouth and interoperculum fringed with a beard of stiff hairs, of which the female shows hardly a trace.

These hairs are of the nature of scales. In another species of the same genus, soft flexible tentacles project

from the front part of the head of the male, which are absent in the female. These tentacles are prolongations

of the true skin, and therefore are not homologous with the stiff hairs of the former species; but it can hardly

be doubted that both serve the same purpose. What this purpose may be, it is difficult to conjecture; ornament

does not here seem probable, but we can hardly suppose that stiff hairs and flexible filaments can be useful in

any ordinary way to the males alone. In that strange monster, the Chimaera monstrosa, the male has a

hookshaped bone on the top of the head, directed forwards, with its end rounded and covered with sharp

spines; in the female "this crown is altogether absent," but what its use may be to the male is utterly

unknown. (19. F. Buckland, in 'Land and Water,' July 1868, p. 377, with a figure. Many other cases could be

The structures as yet referred to are permanent in the male after he has arrived at maturity; but with some

Blennies, and in another allied genus (20. Dr. Gunther, 'Catalogue of Fishes,' vol. iii. pp. 221 and 240.), a

crest is developed on the head of the male only during the breedingseason, and the body at the same time

becomes more brightlycoloured. There can be little doubt that this crest serves as a temporary sexual

ornament, for the female does not exhibit a trace of it. In other species of the same genus both sexes possess a

crest, and in at least one species neither sex is thus provided. In many of the Chromidae, for instance in

Geophagus and especially in Cichla, the males, as I hear from Professor Agassiz (21. See also 'A Journey in

Brazil,' by Prof. and Mrs. Agassiz, 1868, p. 220.), have a conspicuous protuberance on the forehead, which is

wholly wanting in the females and in the young males. Professor Agassiz adds, "I have often observed these

fishes at the time of spawning when the protuberance is largest, and at other seasons when it is totally

wanting, and the two sexes shew no difference whatever in the outline of the profile of the head. I never

could ascertain that it subserves any special function, and the Indians on the Amazon know nothing about its

use." These protuberances resemble, in their periodical appearance, the fleshy carbuncles on the heads of

certain birds; but whether they serve as ornaments must remain at present doubtful.

I hear from Professor Agassiz and Dr. Gunther, that the males of those fishes, which differ permanently in

colour from the females, often become more brilliant during the breedingseason. This is likewise the case

with a multitude of fishes, the sexes of which are identical in colour at all other seasons of the year. The

tench, roach, and perch may be given as instances. The male salmon at this season is "marked on the cheeks

with orangecoloured stripes, which give it the appearance of a Labrus, and the body partakes of a golden

orange tinge. The females are dark in colour, and are commonly called blackfish." (22. Yarrell, 'History of

British Fishes,' vol. ii. 1836, pp. 10, 12, 35.) An analogous and even greater change takes place with the

Salmo eriox or bull trout; the males of the char (S. umbla) are likewise at this season rather brighter in colour

than the females. (23. W. Thompson, in 'Annals and Magazine of Natural History,' vol. vi. 1841, p. 440.) The

colours of the pike (Esox reticulatus) of the United States, especially of the male, become, during the

breedingseason, exceedingly intense, brilliant, and iridescent. (24. 'The American Agriculturalist,' 1868, p.

100.) Another striking instance out of many is afforded by the male stickleback (Gasterosteus leiurus), which

is described by Mr. Warington (25. 'Annals and Mag. of Nat. Hist.' Oct. 1852.), as being then "beautiful

beyond description." The back and eyes of the female are simply brown, and the belly white. The eyes of the

male, on the other hand, are "of the most splendid green, having a metallic lustre like the green feathers of

some hummingbirds. The throat and belly are of a bright crimson, the back of an ashygreen, and the whole

fish appears as though it were somewhat translucent and glowed with an internal incandescence." After the

breeding season these colours all change, the throat and belly become of a paler red, the back more green, and

With respect to the courtship of fishes, other cases have been observed since the first edition of this book

appeared, besides that already given of the stickleback. Mr. W.S. Kent says that the male of the Labrus

mixtus, which, as we have seen, differs in colour from the female, makes "a deep hollow in the sand of the

tank, and then endeavours in the most persuasive manner to induce a female of the same species to share it

with him, swimming backwards and forwards between her and the completed nest, and plainly exhibiting the

greatest anxiety for her to follow." The males of Cantharus lineatus become, during the breedingseason, of

deep leaden black; they then retire from the shoal, and excavate a hollow as a nest. "Each male now mounts

vigilant guard over his respective hollow, and vigorously attacks and drives away any other fish of the same

sex. Towards his companions of the opposite sex his conduct is far different; many of the latter are now

distended with spawn, and these he endeavours by all the means in his power to lure singly to his prepared

hollow, and there to deposit the myriad ova with which they are laden, which he then protects and guards

A more striking case of courtship, as well as of display, by the males of a Chinese Macropus has been given

by M. Carbonnier, who carefully observed these fishes under confinement. (27. 'Bulletin de la Societe

d'Acclimat.' Paris, July 1869, and Jan. 1870.) The males are most beautifully coloured, more so than the

females. During the breedingseason they contend for the possession of the females; and, in the act of

courtship, expand their fins, which are spotted and ornamented with brightly coloured rays, in the same

manner, according to M. Carbonnier, as the peacock. They then also bound about the females with much

vivacity, and appear by "l'etalage de leurs vives couleurs chercher a attirer l'attention des femelles, lesquelles

ne paraissaient indifferentes a ce manege, elles nageaient avec une molle lenteur vers les males et semblaient

se complaire dans leur voisinage." After the male has won his bride, he makes a little disc of froth by blowing

air and mucus out of his mouth. He then collects the fertilised ova, dropped by the female, in his mouth; and

this caused M. Carbonnier much alarm, as he thought that they were going to be devoured. But the male soon

deposits them in the disc of froth, afterwards guarding them, repairing the froth, and taking care of the young

when hatched. I mention these particulars because, as we shall presently see, there are fishes, the males of

which hatch their eggs in their mouths; and those who do not believe in the principle of gradual evolution

might ask how could such a habit have originated; but the difficulty is much diminished when we know that

there are fishes which thus collect and carry the eggs; for if delayed by any cause in depositing them, the

To return to our more immediate subject. The case stands thus: female fishes, as far as I can learn, never

willingly spawn except in the presence of the males; and the males never fertilise the ova except in the

presence of the females. The males fight for the possession of the females. In many species, the males whilst

young resemble the females in colour; but when adult become much more brilliant, and retain their colours

throughout life. In other species the males become brighter than the females and otherwise more highly

ornamented, only during the season of love. The males sedulously court the females, and in one case, as we

have seen, take pains in displaying their beauty before them. Can it be believed that they would thus act to no

purpose during their courtship? And this would be the case, unless the females exert some choice and select

those males which please or excite them most. If the female exerts such choice, all the above facts on the

ornamentation of the males become at once intelligible by the aid of sexual selection.

We have next to inquire whether this view of the bright colours of certain male fishes having been acquired

through sexual selection can, through the law of the equal transmission of characters to both sexes, be

extended to those groups in which the males and females are brilliant in the same, or nearly the same degree

and manner. In such a genus as Labrus, which includes some of the most splendid fishes in the worldfor

instance, the Peacock Labrus (L. pavo), described (28. Bory Saint Vincent, in 'Dict. Class. d'Hist. Nat.' tom.

ix. 1826, p. 151.), with pardonable exaggeration, as formed of polished scales of gold, encrusting

lapislazuli, rubies, sapphires, emeralds, and amethystswe may, with much probability, accept this belief;

for we have seen that the sexes in at least one species of the genus differ greatly in colour. With some fishes,

as with many of the lowest animals, splendid colours may be the direct result of the nature of their tissues and

of the surrounding conditions, without the aid of selection of any kind. The goldfish (Cyprinus auratus),

judging from the analogy of the golden variety of the common carp, is perhaps a case in point, as it may owe

its splendid colours to a single abrupt variation, due to the conditions to which this fish has been subjected

under confinement. It is, however, more probable that these colours have been intensified through artificial

selection, as this species has been carefully bred in China from a remote period. (29. Owing to some remarks

on this subject, made in my work 'On the Variation of Animals under Domestication,' Mr. W.F. Mayers

('Chinese Notes and Queries,' Aug. 1868, p. 123) has searched the ancient Chinese encyclopedias. He finds

that goldfish were first reared in confinement during the Sung Dynasty, which commenced A.D. 960. In the

year 1129 these fishes abounded. In another place it is said that since the year 1548 there has been "produced

at Hangchow a variety called the firefish, from its intensely red colour. It is universally admired, and there

is not a household where it is not cultivated, IN RIVALRY AS TO ITS COLOUR, and as a source of profit.")

Under natural conditions it does not seem probable that beings so highly organised as fishes, and which live

under such complex relations, should become brilliantly coloured without suffering some evil or receiving

some benefit from so great a change, and consequently without the intervention of natural selection.

What, then, are we to conclude in regard to the many fishes, both sexes of which are splendidly coloured?

Mr. Wallace (30. 'Westminster Review,' July 1867, p. 7.) believes that the species which frequent reefs,

where corals and other brightlycoloured organisms abound, are brightly coloured in order to escape

detection by their enemies; but according to my recollection they were thus rendered highly conspicuous. In

the fresh waters of the tropics there are no brilliantlycoloured corals or other organisms for the fishes to

resemble; yet many species in the Amazons are beautifully coloured, and many of the carnivorous Cyprinidae

in India are ornamented with "bright longitudinal lines of various tints." (31. 'Indian Cyprinidae,' by Mr.

M'Clelland, 'Asiatic Researches,' vol. xix. part ii. 1839, p. 230.) Mr. M'Clelland, in describing these fishes,

goes so far as to suppose that "the peculiar brilliancy of their colours" serves as "a better mark for

kingfishers, terns, and other birds which are destined to keep the number of these fishes in check"; but at the

present day few naturalists will admit that any animal has been made conspicuous as an aid to its own

destruction. It is possible that certain fishes may have been rendered conspicuous in order to warn birds and

beasts of prey that they were unpalatable, as explained when treating of caterpillars; but it is not, I believe,

known that any fish, at least any freshwater fish, is rejected from being distasteful to fishdevouring

animals. On the whole, the most probable view in regard to the fishes, of which both sexes are brilliantly

coloured, is that their colours were acquired by the males as a sexual ornament, and were transferred equally,

We have now to consider whether, when the male differs in a marked manner from the female in colour or in

other ornaments, he alone has been modified, the variations being inherited by his male offspring alone; or

whether the female has been specially modified and rendered inconspicuous for the sake of protection, such

modifications being inherited only by the females. It is impossible to doubt that colour has been gained by

many fishes as a protection: no one can examine the speckled upper surface of a flounder, and overlook its

resemblance to the sandy bed of the sea on which it lives. Certain fishes, moreover, can through the action of

the nervous system change their colours in adaptation to surrounding objects, and that within a short time.

(32. G. Pouchet, 'L'Institut.' Nov. 1, 1871, p. 134.) One of the most striking instances ever recorded of an

animal being protected by its colour (as far as it can be judged of in preserved specimens), as well as by its

form, is that given by Dr. Gunther (33. 'Proc. Zoolog. Soc.' 1865, p. 327, pl. xiv. and xv.) of a pipefish,

which, with its reddish streaming filaments, is hardly distinguishable from the seaweed to which it clings

with its prehensile tail. But the question now under consideration is whether the females alone have been

modified for this object. We can see that one sex will not be modified through natural selection for the sake

of protection more than the other, supposing both to vary, unless one sex is exposed for a longer period to

danger, or has less power of escaping from such danger than the other; and it does not appear that with fishes

the sexes differ in these respects. As far as there is any difference, the males, from being generally smaller

and from wandering more about, are exposed to greater danger than the females; and yet, when the sexes

differ, the males are almost always the more conspicuously coloured. The ova are fertilised immediately after

being deposited; and when this process lasts for several days, as in the case of the salmon (34. Yarrell,

'British Fishes,' vol. ii. p. 11.), the female, during the whole time, is attended by the male. After the ova are

fertilised they are, in most cases, left unprotected by both parents, so that the males and females, as far as

oviposition is concerned, are equally exposed to danger, and both are equally important for the production of

fertile ova; consequently the more or less brightlycoloured individuals of either sex would be equally liable

to be destroyed or preserved, and both would have an equal influence on the colours of their offspring.

Certain fishes, belonging to several families, make nests, and some of them take care of their young when

hatched. Both sexes of the bright coloured Crenilabrus massa and melops work together in building their

nests with seaweed, shells, etc. (35. According to the observations of M. Gerbe; see Gunther's 'Record of

Zoolog. Literature,' 1865, p. 194.) But the males of certain fishes do all the work, and afterwards take

exclusive charge of the young. This is the case with the dullcoloured gobies (36. Cuvier, 'Regne Animal,'

vol. ii. 1829, p. 242.), in which the sexes are not known to differ in colour, and likewise with the sticklebacks

(Gasterosteus), in which the males become brilliantly coloured during the spawning season. The male of the

smoothtailed stickleback (G. leiurus) performs the duties of a nurse with exemplary care and vigilance

during a long time, and is continually employed in gently leading back the young to the nest, when they stray

too far. He courageously drives away all enemies including the females of his own species. It would indeed

be no small relief to the male, if the female, after depositing her eggs, were immediately devoured by some

enemy, for he is forced incessantly to drive her from the nest. (37. See Mr. Warington's most interesting

description of the habits of the Gasterosteus leiurus in 'Annals and Magazine of Nat. History,' November

The males of certain other fishes inhabiting South America and Ceylon, belonging to two distinct Orders,

have the extraordinary habit of hatching within their mouths, or branchial cavities, the eggs laid by the

females. (38. Prof. Wyman, in 'Proc. Boston Soc. of Nat. Hist.' Sept. 15, 1857. Also Prof. Turner, in 'Journal

of Anatomy and Physiology,' Nov. 1, 1866, p. 78. Dr. Gunther has likewise described other cases.) I am

informed by Professor Agassiz that the males of the Amazonian species which follow this habit, "not only are

generally brighter than the females, but the difference is greater at the spawningseason than at any other

time." The species of Geophagus act in the same manner; and in this genus, a conspicuous protuberance

becomes developed on the forehead of the males during the breedingseason. With the various species of

Chromids, as Professor Agassiz likewise informs me, sexual differences in colour may be observed, "whether

they lay their eggs in the water among aquatic plants, or deposit them in holes, leaving them to come out

without further care, or build shallow nests in the river mud, over which they sit, as our Pomotis does. It

ought also to be observed that these sitters are among the brightest species in their respective families; for

instance, Hygrogonus is bright green, with large black ocelli, encircled with the most brilliant red." Whether

with all the species of Chromids it is the male alone which sits on the eggs is not known. It is, however,

manifest that the fact of the eggs being protected or unprotected by the parents, has had little or no influence

on the differences in colour between the sexes. It is further manifest, in all the cases in which the males take

exclusive charge of the nests and young, that the destruction of the brightercoloured males would be far

more influential on the character of the race, than the destruction of the brightercoloured females; for the

death of the male during the period of incubation or nursing would entail the death of the young, so that they

could not inherit his peculiarities; yet, in many of these very cases the males are more conspicuously coloured

In most of the Lophobranchii (Pipefish, Hippocampi, etc.) the males have either marsupial sacks or

hemispherical depressions on the abdomen, in which the ova laid by the female are hatched. The males also

shew great attachment to their young. (39. Yarrell, 'History of British Fishes,' vol. ii. 1836, pp. 329, 338.) The

sexes do not commonly differ much in colour; but Dr. Gunther believes that the male Hippocampi are rather

brighter than the females. The genus Solenostoma, however, offers a curious exceptional case (40. Dr.

Gunther, since publishing an account of this species in 'The Fishes of Zanzibar,' by Col. Playfair, 1866, p.

137, has reexamined the specimens, and has given me the above information.), for the female is much more

vividlycoloured and spotted than the male, and she alone has a marsupial sack and hatches the eggs; so that

the female of Solenostoma differs from all the other Lophobranchii in this latter respect, and from almost all

other fishes, in being more brightlycoloured than the male. It is improbable that this remarkable double

inversion of character in the female should be an accidental coincidence. As the males of several fishes,

which take exclusive charge of the eggs and young, are more brightly coloured than the females, and as here

the female Solenostoma takes the same charge and is brighter than the male, it might be argued that the

conspicuous colours of that sex which is the more important of the two for the welfare of the offspring, must

be in some manner protective. But from the large number of fishes, of which the males are either permanently

or periodically brighter than the females, but whose life is not at all more important for the welfare of the

species than that of the female, this view can hardly be maintained. When we treat of birds we shall meet

with analogous cases, where there has been a complete inversion of the usual attributes of the two sexes, and

we shall then give what appears to be the probable explanation, namely, that the males have selected the more

attractive females, instead of the latter having selected, in accordance with the usual rule throughout the

On the whole we may conclude, that with most fishes, in which the sexes differ in colour or in other

ornamental characters, the males originally varied, with their variations transmitted to the same sex, and

accumulated through sexual selection by attracting or exciting the females. In many cases, however, such

characters have been transferred, either partially or completely, to the females. In other cases, again, both

sexes have been coloured alike for the sake of protection; but in no instance does it appear that the female

alone has had her colours or other characters specially modified for this latter purpose.

The last point which need be noticed is that fishes are known to make various noises, some of which are

described as being musical. Dr. Dufosse, who has especially attended to this subject, says that the sounds are

voluntarily produced in several ways by different fishes: by the friction of the pharyngeal bonesby the

vibration of certain muscles attached to the swim bladder, which serves as a resounding boardand by the

vibration of the intrinsic muscles of the swim bladder. By this latter means the Trigla produces pure and

longdrawn sounds which range over nearly an octave. But the most interesting case for us is that of two

species of Ophidium, in which the males alone are provided with a soundproducing apparatus, consisting of

small movable bones, with proper muscles, in connection with the swim bladder. (41. 'ComptesRendus,'

tom. xlvi. 1858, p. 353; tom. xlvii. 1858, p. 916; tom. liv. 1862, p. 393. The noise made by the Umbrinas

(Sciaena aquila), is said by some authors to be more like that of a flute or organ, than drumming: Dr.

Zouteveen, in the Dutch translation of this work (vol. ii. p. 36), gives some further particulars on the sounds

made by fishes.) The drumming of the Umbrinas in the European seas is said to be audible from a depth of

twenty fathoms; and the fishermen of Rochelle assert "that the males alone make the noise during the

spawningtime; and that it is possible by imitating it, to take them without bait." (42. The Rev. C. Kingsley,

in 'Nature,' May 1870, p. 40.) From this statement, and more especially from the case of Ophidium, it is

almost certain that in this, the lowest class of the Vertebrata, as with so many insects and spiders,

soundproducing instruments have, at least in some cases, been developed through sexual selection, as a

[Fig. 32. Triton cristatus (half natural size, from Bell's 'British Reptiles'). Upper figure, male during the

I will begin with the tailed amphibians. The sexes of salamanders or newts often differ much both in colour

and structure. In some species prehensile claws are developed on the forelegs of the males during the

breeding season: and at this season in the male Triton palmipes the hindfeet are provided with a

swimmingweb, which is almost completely absorbed during the winter; so that their feet then resemble

those of the female. (43. Bell, 'History of British Reptiles,' 2nd ed., 1849, pp. 156159.) This structure no

doubt aids the male in his eager search and pursuit of the female. Whilst courting her he rapidly vibrates the

end of his tail. With our common newts (Triton punctatus and cristatus) a deep, much indented crest is

developed along the back and tail of the male during the breeding season, which disappears during the

winter. Mr. St. George Mivart informs me that it is not furnished with muscles, and therefore cannot be used

for locomotion. As during the season of courtship it becomes edged with bright colours, there can hardly be a

doubt that it is a masculine ornament. In many species the body presents strongly contrasted, though lurid

tints, and these become more vivid during the breedingseason. The male, for instance, of our common little

newt (Triton punctatus) is "brownishgrey above, passing into yellow beneath, which in the spring becomes a

rich bright orange, marked everywhere with round dark spots." The edge of the crest also is then tipped with

bright red or violet. The female is usually of a yellowishbrown colour with scattered brown dots, and the

lower surface is often quite plain. (44. Bell, 'History of British Reptiles,' 2nd ed., 1849, pp. 146, 151.) The

young are obscurely tinted. The ova are fertilised during the act of deposition, and are not subsequently

tended by either parent. We may therefore conclude that the males have acquired their stronglymarked

colours and ornamental appendages through sexual selection; these being transmitted either to the male

With many frogs and toads the colours evidently serve as a protection, such as the bright green tints of tree

frogs and the obscure mottled shades of many terrestrial species. The most conspicuouslycoloured toad

which I ever saw, the Phryniscus nigricans (45. 'Zoology of the Voyage of the "Beagle,"' 1843. Bell, ibid. p.

49.), had the whole upper surface of the body as black as ink, with the soles of the feet and parts of the

abdomen spotted with the brightest vermilion. It crawled about the bare sandy or open grassy plains of La

Plata under a scorching sun, and could not fail to catch the eye of every passing creature. These colours are

probably beneficial by making this animal known to all birds of prey as a nauseous mouthful.

In Nicaragua there is a little frog "dressed in a bright livery of red and blue" which does not conceal itself like

most other species, but hops about during the daytime, and Mr. Belt says (46. 'The Naturalist in Nicaragua,'

1874, p. 321.) that as soon as he saw its happy sense of security, he felt sure that it was uneatable. After

several trials he succeeded in tempting a young duck to snatch up a young one, but it was instantly rejected;

and the duck "went about jerking its head, as if trying to throw off some unpleasant taste."

With respect to sexual differences of colour, Dr. Gunther does not know of any striking instance either with

frogs or toads; yet he can often distinguish the male from the female by the tints of the former being a little

more intense. Nor does he know of any striking difference in external structure between the sexes, excepting

the prominences which become developed during the breedingseason on the front legs of the male, by

which he is enabled to hold the female. (47. The male alone of the Bufo sikimmensis (Dr. Anderson, 'Proc.

Zoolog. Soc.' 1871, p. 204) has two platelike callosities on the thorax and certain rugosities on the fingers,

which perhaps subserve the same end as the abovementioned prominences.) It is surprising that these

animals have not acquired more stronglymarked sexual characters; for though coldblooded their passions

are strong. Dr. Gunther informs me that he has several times found an unfortunate female toad dead and

smothered from having been so closely embraced by three or four males. Frogs have been observed by

Professor Hoffman in Giessen fighting all day long during the breedingseason, and with so much violence

Frogs and toads offer one interesting sexual difference, namely, in the musical powers possessed by the

males; but to speak of music, when applied to the discordant and overwhelming sounds emitted by male

bullfrogs and some other species, seems, according to our taste, a singularly inappropriate expression.

Nevertheless, certain frogs sing in a decidedly pleasing manner. Near Rio Janeiro I used often to sit in the

evening to listen to a number of little Hylae, perched on blades of grass close to the water, which sent forth

sweet chirping notes in harmony. The various sounds are emitted chiefly by the males during the

breedingseason, as in the case of the croaking of our common frog. (48. Bell, 'History British Reptiles,'

1849, p. 93.) In accordance with this fact the vocal organs of the males are more highlydeveloped than those

of the females. In some genera the males alone are provided with sacs which open into the larynx. (49. J.

Bishop, in 'Todd's Cyclopaedia of Anatomy and Physiology,' vol. iv. p. 1503.) For instance, in the edible frog

(Rana esculenta) "the sacs are peculiar to the males, and become, when filled with air in the act of croaking,

large globular bladders, standing out one on each side of the head, near the corners of the mouth." The croak

of the male is thus rendered exceedingly powerful; whilst that of the female is only a slight groaning noise.

(50. Bell, ibid. pp. 112114.) In the several genera of the family the vocal organs differ considerably in

structure, and their development in all cases may be attributed to sexual selection.

Tortoises and turtles do not offer wellmarked sexual differences. In some species, the tail of the male is

longer than that of the female. In some, the plastron or lower surface of the shell of the male is slightly

concave in relation to the back of the female. The male of the mudturtle of the United States (Chrysemys

picta) has claws on its front feet twice as long as those of the female; and these are used when the sexes unite.

(51. Mr. C.J. Maynard, 'The American Naturalist,' Dec. 1869, p. 555.) With the huge tortoise of the

Galapagos Islands (Testudo nigra) the males are said to grow to a larger size than the females: during the

pairingseason, and at no other time, the male utters a hoarse bellowing noise, which can be heard at the

distance of more than a hundred yards; the female, on the other hand, never uses her voice. (52. See my

With the Testudo elegans of India, it is said "that the combats of the males may be heard at some distance,

from the noise they produce in butting against each other." (53. Dr. Gunther, 'Reptiles of British India,' 1864,

The sexes apparently do not differ in colour; nor do I know that the males fight together, though this is

probable, for some kinds make a prodigious display before the females. Bartram (54. 'Travels through

Carolina,' etc., 1791, p. 128.) describes the male alligator as striving to win the female by splashing and

roaring in the midst of a lagoon, "swollen to an extent ready to burst, with its head and tail lifted up, he

springs or twirls round on the surface of the water, like an Indian chief rehearsing his feats of war." During

the season of love, a musky odour is emitted by the submaxiliary glands of the crocodile, and pervades their

Dr. Gunther informs me that the males are always smaller than the females, and generally have longer and

slenderer tails; but he knows of no other difference in external structure. In regard to colour, be can almost

always distinguish the male from the female, by his more strongly pronounced tints; thus the black zigzag

band on the back of the male English viper is more distinctly defined than in the female. The difference is

much plainer in the rattlesnakes of N. America, the male of which, as the keeper in the Zoological Gardens

shewed me, can at once be distinguished from the female by having more lurid yellow about its whole body.

In S. Africa the Bucephalus capensis presents an analogous difference, for the female "is never so fully

variegated with yellow on the sides as the male." (56. Sir Andrew Smith, 'Zoology of S. Africa: Reptilia,'

1849, pl. x.) The male of the Indian Dipsas cynodon, on the other hand, is blackishbrown, with the belly

partly black, whilst the female is reddish or yellowisholive, with the belly either uniform yellowish or

marbled with black. In the Tragops dispar of the same country the male is bright green, and the female

bronzecoloured. (57. Dr. A. Gunther, 'Reptiles of British India,' Ray Soc., 1864, pp. 304, 308.) No doubt the

colours of some snakes are protective, as shewn by the green tints of treesnakes, and the various mottled

shades of the species which live in sandy places; but it is doubtful whether the colours of many kinds, for

instance of the common English snake and viper, serve to conceal them; and this is still more doubtful with

the many foreign species which are coloured with extreme elegance. The colours of certain species are very

different in the adult and young states. (58. Dr. Stoliczka, 'Journal of Asiatic Society of Bengal,' vol. xxxix,

During the breedingseason the anal scentglands of snakes are in active function (59. Owen, 'Anatomy of

Vertebrates,' vol. i. 1866, p. 615.); and so it is with the same glands in lizards, and as we have seen with the

submaxiliary glands of crocodiles. As the males of most animals search for the females, these odoriferous

glands probably serve to excite or charm the female, rather than to guide her to the spot where the male may

be found. Male snakes, though appearing so sluggish, are amorous; for many have been observed crowding

round the same female, and even round her dead body. They are not known to fight together from rivalry.

Their intellectual powers are higher than might have been anticipated. In the Zoological Gardens they soon

learn not to strike at the iron bar with which their cages are cleaned; and Dr. Keen of Philadelphia informs me

that some snakes which he kept learned after four or five times to avoid a noose, with which they were at first

easily caught. An excellent observer in Ceylon, Mr. E. Layard, saw (60. 'Rambles in Ceylon,' in 'Annals and

Magazine of Natural History,' 2nd series, vol. ix. 1852, p. 333.) a cobra thrust its head through a narrow hole

and swallow a toad. "With this encumbrance he could not withdraw himself; finding this, he reluctantly

disgorged the precious morsel, which began to move off; this was too much for snake philosophy to bear, and

the toad was again seized, and again was the snake, after violent efforts to escape, compelled to part with its

prey. This time, however, a lesson had been learnt, and the toad was seized by one leg, withdrawn, and then

The keeper in the Zoological Gardens is positive that certain snakes, for instance Crotalus and Python,

distinguish him from all other persons. Cobras kept together in the same cage apparently feel some

attachment towards each other. (61. Dr. Gunther, 'Reptiles of British India,' 1864, p. 340.)

It does not, however, follow because snakes have some reasoning power, strong passions and mutual

affection, that they should likewise be endowed with sufficient taste to admire brilliant colours in their

partners, so as to lead to the adornment of the species through sexual selection. Nevertheless, it is difficult to

account in any other manner for the extreme beauty of certain species; for instance, of the coralsnakes of S.

America, which are of a rich red with black and yellow transverse bands. I well remember how much surprise

I felt at the beauty of the first coral snake which I saw gliding across a path in Brazil. Snakes coloured in

this peculiar manner, as Mr. Wallace states on the authority of Dr. Gunther (62. 'Westminster Review,' July

1st, 1867, p. 32.), are found nowhere else in the world except in S. America, and here no less than four genera

occur. One of these, Elaps, is venomous; a second and widelydistinct genus is doubtfully venomous, and the

two others are quite harmless. The species belonging to these distinct genera inhabit the same districts, and

are so like each other that no one "but a naturalist would distinguish the harmless from the poisonous kinds."

Hence, as Mr. Wallace believes, the innocuous kinds have probably acquired their colours as a protection, on

the principle of imitation; for they would naturally be thought dangerous by their enemies. The cause,

however, of the bright colours of the venomous Elaps remains to be explained, and this may perhaps be

Snakes produce other sounds besides hissing. The deadly Echis carinata has on its sides some oblique rows of

scales of a peculiar structure with serrated edges; and when this snake is excited these scales are rubbed

against each other, which produces "a curious prolonged, almost hissing sound." (63. Dr. Anderson, 'Proc.

Zoolog. Soc.' 1871, p. 196.) With respect to the rattling of the rattlesnake, we have at last some definite

information: for Professor Aughey states (64. The 'American Naturalist,' 1873, p. 85.), that on two occasions,

being himself unseen, he watched from a little distance a rattlesnake coiled up with head erect, which

continued to rattle at short intervals for half an hour: and at last he saw another snake approach, and when

they met they paired. Hence he is satisfied that one of the uses of the rattle is to bring the sexes together.

Unfortunately he did not ascertain whether it was the male or the female which remained stationary and

called for the other. But it by no means follows from the above fact that the rattle may not be of use to these

snakes in other ways, as a warning to animals which would otherwise attack them. Nor can I quite disbelieve

the several accounts which have appeared of their thus paralysing their prey with fear. Some other snakes

also make a distinct noise by rapidly vibrating their tails against the surrounding stalks of plants; and I have

The males of some, probably of many kinds of lizards, fight together from rivalry. Thus the arboreal Anolis

cristatellus of S. America is extremely pugnacious: "During the spring and early part of the summer, two

adult males rarely meet without a contest. On first seeing one another, they nod their heads up and down three

or four times, and at the same time expanding the frill or pouch beneath the throat; their eyes glisten with

rage, and after waving their tails from side to side for a few seconds, as if to gather energy, they dart at each

other furiously, rolling over and over, and holding firmly with their teeth. The conflict generally ends in one

of the combatants losing his tail, which is often devoured by the victor." The male of this species is

considerably larger than the female (65. Mr. N.L. Austen kept these animals alive for a considerable time; see

'Land and Water,' July 1867, p. 9.); and this, as far as Dr. Gunther has been able to ascertain, is the general

rule with lizards of all kinds. The male alone of the Cyrtodactylus rubidus of the Andaman Islands possesses

preanal pores; and these pores, judging from analogy, probably serve to emit an odour. (66. Stoliczka,

[Fig.33. Sitana minor. Male with the gular pouch expanded (from Gunther's 'Reptiles of India')']

The sexes often differ greatly in various external characters. The male of the abovementioned Anolis is

furnished with a crest which runs along the back and tail, and can be erected at pleasure; but of this crest the

female does not exhibit a trace. In the Indian Cophotis ceylanica, the female has a dorsal crest, though much

less developed than in the male; and so it is, as Dr. Gunther informs me, with the females of many Iguanas,

Chameleons, and other lizards. In some species, however, the crest is equally developed in both sexes, as in

the Iguana tuberculata. In the genus Sitana, the males alone are furnished with a large throat pouch (Fig. 33),

which can be folded up like a fan, and is coloured blue, black, and red; but these splendid colours are

exhibited only during the pairingseason. The female does not possess even a rudiment of this appendage. In

the Anolis cristatellus, according to Mr. Austen, the throat pouch, which is bright red marbled with yellow, is

present in the female, though in a rudimental condition. Again, in certain other lizards, both sexes are equally

well provided with throat pouches. Here we see with species belonging to the same group, as in so many

previous cases, the same character either confined to the males, or more largely developed in them than in the

females, or again equally developed in both sexes. The little lizards of the genus Draco, which glide through

the air on their rib supported parachutes, and which in the beauty of their colours baffle description, are

furnished with skinny appendages to the throat "like the wattles of gallinaceous birds." These become erected

when the animal is excited. They occur in both sexes, but are best developed when the male arrives at

maturity, at which age the middle appendage is sometimes twice as long as the head. Most of the species

likewise have a low crest running along the neck; and this is much more developed in the fullgrown males

than in the females or young males. (67. All the foregoing statements and quotations, in regard to Cophotis,

Sitana and Draco, as well as the following facts in regard to Ceratophora and Chamaeleon, are from Dr.

Gunther himself, or from his magnificent work on the 'Reptiles of British India,' Ray Soc., 1864, pp. 122,

A Chinese species is said to live in pairs during the spring; "and if one is caught, the other falls from the tree

to the ground, and allows itself to be captured with impunity"I presume from despair. (68. Mr. Swinhoe,

There are other and much more remarkable differences between the sexes of certain lizards. The male of

Ceratophora aspera bears on the extremity of his snout an appendage half as long as the head. It is cylindrical,

covered with scales, flexible, and apparently capable of erection: in the female it is quite rudimental. In a

second species of the same genus a terminal scale forms a minute horn on the summit of the flexible

appendage; and in a third species (C. Stoddartii, fig. 34) the whole appendage is converted into a horn, which

is usually of a white colour, but assumes a purplish tint when the animal is excited. In the adult male of this

latter species the horn is half an inch in length, but it is of quite minute size in the female and in the young.

These appendages, as Dr. Gunther has remarked to me, may be compared with the combs of gallinaceous

In the genus Chamaeleon we come to the acme of difference between the sexes. The upper part of the skull of

the male C. bifurcus (Fig. 35), an inhabitant of Madagascar, is produced into two great, solid, bony

projections, covered with scales like the rest of the head; and of this wonderful modification of structure the

female exhibits only a rudiment. Again, in Chamaeleo Owenii (Fig. 36), from the West Coast of Africa, the

male bears on his snout and forehead three curious horns, of which the female has not a trace. These horns

consist of an excrescence of bone covered with a smooth sheath, forming part of the general integuments of

the body, so that they are identical in structure with those of a bull, goat, or other sheathhorned ruminant.

Although the three horns differ so much in appearance from the two great prolongations of the skull in C.

bifurcus, we can hardly doubt that they serve the same general purpose in the economy of these two animals.

The first conjecture, which will occur to every one, is that they are used by the males for fighting together;

and as these animals are very quarrelsome (69. Dr. Buchholz, 'Monatsbericht K. Preuss. Akad.' Jan. 1874, p.

78.), this is probably a correct view. Mr. T.W. Wood also informs me that he once watched two individuals of

C. pumilus fighting violently on the branch of a tree; they flung their heads about and tried to bite each other;

With many lizards the sexes differ slightly in colour, the tints and stripes of the males being brighter and

more distinctly defined than in the females. This, for instance, is the case with the above Cophotis and with

the Acanthodactylus capensis of S. Africa. In a Cordylus of the latter country, the male is either much redder

or greener than the female. In the Indian Calotes nigrilabris there is a still greater difference; the lips also of

the male are black, whilst those of the female are green. In our common little viviparous lizard (Zootoca

vivipara) "the under side of the body and base of the tail in the male are bright orange, spotted with black; in

the female these parts are palegreyishgreen without spots." (70. Bell, 'History of British Reptiles,' 2nd ed.,

1849, p. 40.) We have seen that the males alone of Sitana possess a throatpouch; and this is splendidly tinted

with blue, black, and red. In the Proctotretus tenuis of Chile the male alone is marked with spots of blue,

green, and copperyred. (71. For Proctotretus, see 'Zoology of the Voyage of the "Beagle"; Reptiles,' by Mr.

Bell, p. 8. For the Lizards of S. Africa, see 'Zoology of S. Africa: Reptiles,' by Sir Andrew Smith, pl. 25 and

39. For the Indian Calotes, see 'Reptiles of British India,' by Dr. Gunther, p. 143.) In many cases the males

retain the same colours throughout the year, but in others they become much brighter during the

breedingseason; I may give as an additional instance the Calotes maria, which at this season has a bright red

head, the rest of the body being green. (72. Gunther in 'Proceedings, Zoological Society,' 1870, p. 778, with a

Both sexes of many species are beautifully coloured exactly alike; and there is no reason to suppose that such

colours are protective. No doubt with the bright green kinds which live in the midst of vegetation, this colour

serves to conceal them; and in N. Patagonia I saw a lizard (Proctotretus multimaculatus) which, when

frightened, flattened its body, closed its eyes, and then from its mottled tints was hardly distinguishable from

the surrounding sand. But the bright colours with which so many lizards are ornamented, as well as their

various curious appendages, were probably acquired by the males as an attraction, and then transmitted either

to their male offspring alone, or to both sexes. Sexual selection, indeed, seems to have played almost as

important a part with reptiles as with birds; and the less conspicuous colours of the females in comparison

with the males cannot be accounted for, as Mr. Wallace believes to be the case with birds, by the greater

Sexual differencesLaw of battleSpecial weaponsVocal organs Instrumental musicLoveantics

and dancesDecorations, permanent and seasonalDouble and single annual moultsDisplay of

Secondary sexual characters are more diversified and conspicuous in birds, though not perhaps entailing more

important changes of structure, than in any other class of animals. I shall, therefore, treat the subject at

considerable length. Male birds sometimes, though rarely, possess special weapons for fighting with each

other. They charm the female by vocal or instrumental music of the most varied kinds. They are ornamented

by all sorts of combs, wattles, protuberances, horns, airdistended sacks, top knots, naked shafts, plumes

and lengthened feathers gracefully springing from all parts of the body. The beak and naked skin about the

head, and the feathers, are often gorgeously coloured. The males sometimes pay their court by dancing, or by

fantastic antics performed either on the ground or in the air. In one instance, at least, the male emits a musky

odour, which we may suppose serves to charm or excite the female; for that excellent observer, Mr. Ramsay

(1. 'Ibis,' vol. iii. (new series), 1867, p. 414.), says of the Australian muskduck (Biziura lobata) that "the

smell which the male emits during the summer months is confined to that sex, and in some individuals is

retained throughout the year; I have never, even in the breedingseason, shot a female which had any smell

of musk." So powerful is this odour during the pairingseason, that it can be detected long before the bird can

be seen. (2. Gould, 'Handbook of the Birds of Australia,' 1865, vol. ii. p. 383.) On the whole, birds appear to

be the most aesthetic of all animals, excepting of course man, and they have nearly the same taste for the

beautiful as we have. This is shewn by our enjoyment of the singing of birds, and by our women, both

civilised and savage, decking their heads with borrowed plumes, and using gems which are hardly more

brilliantly coloured than the naked skin and wattles of certain birds. In man, however, when cultivated, the

sense of beauty is manifestly a far more complex feeling, and is associated with various intellectual ideas.

Before treating of the sexual characters with which we are here more particularly concerned, I may just allude

to certain differences between the sexes which apparently depend on differences in their habits of life; for

such cases, though common in the lower, are rare in the higher classes. Two hummingbirds belonging to the

genus Eustephanus, which inhabit the island of Juan Fernandez, were long thought to be specifically distinct,

but are now known, as Mr. Gould informs me, to be the male and female of the same species, and they differ

slightly in the form of the beak. In another genus of hummingbirds (Grypus), the beak of the male is

serrated along the margin and hooked at the extremity, thus differing much from that of the female. In the

Neomorpha of New Zealand, there is, as we have seen, a still wider difference in the form of the beak in

relation to the manner of feeding of the two sexes. Something of the same kind has been observed with the

goldfinch (Carduelis elegans), for I am assured by Mr. J. Jenner Weir that the birdcatchers can distinguish

the males by their slightly longer beaks. The flocks of males are often found feeding on the seeds of the teazle

(Dipsacus), which they can reach with their elongated beaks, whilst the females more commonly feed on the

seeds of the betony or Scrophularia. With a slight difference of this kind as a foundation, we can see how the

beaks of the two sexes might be made to differ greatly through natural selection. In some of the above cases,

however, it is possible that the beaks of the males may have been first modified in relation to their contests

with other males; and that this afterwards led to slightly changed habits of life.

Almost all male birds are extremely pugnacious, using their beaks, wings, and legs for fighting together. We

see this every spring with our robins and sparrows. The smallest of all birds, namely the hummingbird, is

one of the most quarrelsome. Mr. Gosse (3. Quoted by Mr. Gould, 'Introduction to the Trochilidae,' 1861,

page 29.) describes a battle in which a pair seized hold of each other's beaks, and whirled round and round,

till they almost fell to the ground; and M. Montes de Oca, in speaking or another genus of hummingbird,

says that two males rarely meet without a fierce aerial encounter: when kept in cages "their fighting has

mostly ended in the splitting of the tongue of one of the two, which then surely dies from being unable to

feed." (4. Gould, ibid. p. 52.) With waders, the males of the common waterhen (Gallinula chloropus) "when

pairing, fight violently for the females: they stand nearly upright in the water and strike with their feet." Two

were seen to be thus engaged for half an hour, until one got hold of the head of the other, which would have

been killed had not the observer interfered; the female all the time looking on as a quiet spectator. (5. W.

Thompson, 'Natural History of Ireland: Birds,' vol. ii. 1850, p. 327.) Mr. Blyth informs me that the males of

an allied bird (Gallicrex cristatus) are a third larger than the females, and are so pugnacious during the

breedingseason that they are kept by the natives of Eastern Bengal for the sake of fighting. Various other

birds are kept in India for the same purpose, for instance, the bulbuls (Pycnonotus hoemorrhous) which "fight

The polygamous ruff (Machetes pugnax, Fig. 37) is notorious for his extreme pugnacity; and in the spring,

the males, which are considerably larger than the females, congregate day after day at a particular spot, where

the females propose to lay their eggs. The fowlers discover these spots by the turf being trampled somewhat

bare. Here they fight very much like game cocks, seizing each other with their beaks and striking with their

wings. The great ruff of feathers round the neck is then erected, and according to Col. Montagu "sweeps the

ground as a shield to defend the more tender parts"; and this is the only instance known to me in the case of

birds of any structure serving as a shield. The ruff of feathers, however, from its varied and rich colours

probably serves in chief part as an ornament. Like most pugnacious birds, they seem always ready to fight,

and when closely confined, often kill each other; but Montagu observed that their pugnacity becomes greater

during the spring, when the long feathers on their necks are fully developed; and at this period the least

movement by any one bird provokes a general battle. (7. Macgillivray, 'History of British Birds,' vol. iv.

1852, pp. 177181.) Of the pugnacity of webfooted birds, two instances will suffice: in Guiana "bloody

fights occur during the breedingseason between the males of the wild muskduck (Cairina moschata); and

where these fights have occurred the river is covered for some distance with feathers." (8. Sir R.

Schomburgk, in 'Journal of Royal Geographic Society,' vol. xiii. 1843, p. 31.) Birds which seem illadapted

for fighting engage in fierce conflicts; thus the stronger males of the pelican drive away the weaker ones,

snapping with their huge beaks and giving heavy blows with their wings. Male snipe fight together, "tugging

and pushing each other with their bills in the most curious manner imaginable." Some few birds are believed

never to fight; this is the case, according to Audubon, with one of the woodpeckers of the United States (Picu

sauratus), although "the hens are followed by even half a dozen of their gay suitors." (9. 'Ornithological

Biography,' vol. i. p. 191. For pelicans and snipes, see vol. iii. pp. 138, 477.)

The males of many birds are larger than the females, and this no doubt is the result of the advantage gained

by the larger and stronger males over their rivals during many generations. The difference in size between the

two sexes is carried to an extreme point in several Australian species; thus the male muskduck (Biziura),

and the male Cincloramphus cruralis (allied to our pipits) are by measurement actually twice as large as their

respective females. (10. Gould, 'Handbook of Birds of Australia,' vol. i. p. 395; vol. ii. p. 383.) With many

other birds the females are larger than the males; and, as formerly remarked, the explanation often given,

namely, that the females have most of the work in feeding their young, will not suffice. In some few cases, as

we shall hereafter see, the females apparently have acquired their greater size and strength for the sake of

The males of many gallinaceous birds, especially of the polygamous kinds, are furnished with special

weapons for fighting with their rivals, namely spurs, which can be used with fearful effect. It has been

recorded by a trustworthy writer (11. Mr. Hewitt, in the 'Poultry Book' by Tegetmeier, 1866, p. 137.) that in

Derbyshire a kite struck at a gamehen accompanied by her chickens, when the cock rushed to the rescue,

and drove his spur right through the eye and skull of the aggressor. The spur was with difficulty drawn from

the skull, and as the kite, though dead, retained his grasp, the two birds were firmly locked together; but the

cock when disentangled was very little injured. The invincible courage of the game cock is notorious: a

gentleman who long ago witnessed the brutal scene, told me that a bird had both its legs broken by some

accident in the cockpit, and the owner laid a wager that if the legs could be spliced so that the bird could

stand upright, he would continue fighting. This was effected on the spot, and the bird fought with undaunted

courage until he received his deathstroke. In Ceylon a closely allied, wild species, the Gallus Stanleyi, is

known to fight desperately "in defence of his seraglio," so that one of the combatants is frequently found

dead. (12. Layard, 'Annals and Magazine of Natural History,' vol. xiv. 1854, p. 63.) An Indian partridge

(Ortygornis gularis), the male of which is furnished with strong and sharp spurs, is so quarrelsome "that the

scars of former fights disfigure the breast of almost every bird you kill." (13. Jerdon, 'Birds of India,' vol. iii.

The males of almost all gallinaceous birds, even those which are not furnished with spurs, engage during the

breedingseason in fierce conflicts. The Capercailzie and Blackcock (Tetrao urogallus and T. tetrix), which

are both polygamists, have regular appointed places, where during many weeks they congregate in numbers

to fight together and to display their charms before the females. Dr. W. Kovalevsky informs me that in Russia

he has seen the snow all bloody on the arenas where the capercailzie have fought; and the blackcocks "make

the feathers fly in every direction," when several "engage in a battle royal." The elder Brehm gives a curious

account of the Balz, as the lovedances and lovesongs of the Blackcock are called in Germany. The bird

utters almost continuously the strangest noises: "he holds his tail up and spreads it out like a fan, he lifts up

his head and neck with all the feathers erect, and stretches his wings from the body. Then he takes a few

jumps in different directions, sometimes in a circle, and presses the under part of his beak so hard against the

ground that the chin feathers are rubbed off. During these movements he beats his wings and turns round and

round. The more ardent he grows the more lively he becomes, until at last the bird appears like a frantic

creature." At such times the blackcocks are so absorbed that they become almost blind and deaf, but less so

than the capercailzie: hence bird after bird may be shot on the same spot, or even caught by the hand. After

performing these antics the males begin to fight: and the same blackcock, in order to prove his strength over

several antagonists, will visit in the course of one morning several Balzplaces, which remain the same

during successive years. (14. Brehm, 'Thierleben,' 1867, B. iv. s. 351. Some of the foregoing statements are

The peacock with his long train appears more like a dandy than a warrior, but he sometimes engages in fierce

contests: the Rev. W. Darwin Fox informs me that at some little distance from Chester two peacocks became

so excited whilst fighting, that they flew over the whole city, still engaged, until they alighted on the top of

The spur, in those gallinaceous birds which are thus provided, is generally single; but Polyplectron (Fig. 51)

has two or more on each leg; and one of the Bloodpheasants (Ithaginis cruentus) has been seen with five

spurs. The spurs are generally confined to the male, being represented by mere knobs or rudiments in the

female; but the females of the Java peacock (Pavo muticus) and, as I am informed by Mr. Blyth, of the small

firebacked pheasant (Euplocamus erythrophthalmus) possess spurs. In Galloperdix it is usual for the males

to have two spurs, and for the females to have only one on each leg. (15. Jerdon, 'Birds of India': on Ithaginis,

vol. iii. p. 523; on Galloperdix, p. 541.) Hence spurs may be considered as a masculine structure, which has

been occasionally more or less transferred to the females. Like most other secondary sexual characters, the

[Fig.38. Palamedea cornuta (from Brehm), shewing the double wingspurs, and the filament on the head.]

Various birds have spurs on their wings. But the Egyptian goose (Chenalopex aegyptiacus) has only "bare

obtuse knobs," and these probably shew us the first steps by which true spurs have been developed in other

species. In the spurwinged goose, Plectropterus gambensis, the males have much larger spurs than the

females; and they use them, as I am informed by Mr. Bartlett, in fighting together, so that, in this case, the

wingspurs serve as sexual weapons; but according to Livingstone, they are chiefly used in the defence of the

young. The Palamedea (Fig. 38) is armed with a pair of spurs on each wing; and these are such formidable

weapons that a single blow has been known to drive a dog howling away. But it does not appear that the

spurs in this case, or in that of some of the spurwinged rails, are larger in the male than in the female. (16.

For the Egyptian goose, see Macgillivray, 'British Birds,' vol. iv. p. 639. For Plectropterus, Livingstone's

'Travels,' p. 254. For Palamedea, Brehm's 'Thierleben,' B. iv. s. 740. See also on this bird Azara, 'Voyages

dans l'Amerique merid.' tom. iv. 1809, pp. 179, 253.) In certain plovers, however, the wingspurs must be

considered as a sexual character. Thus in the male of our common peewit (Vanellus cristatus) the tubercle on

the shoulder of the wing becomes more prominent during the breedingseason, and the males fight together.

In some species of Lobivanellus a similar tubercle becomes developed during the breedingseason "into a

short horny spur." In the Australian L. lobatus both sexes have spurs, but these are much larger in the males

than in the females. In an allied bird, the Hoplopterus armatus, the spurs do not increase in size during the

breeding season; but these birds have been seen in Egypt to fight together, in the same manner as our

peewits, by turning suddenly in the air and striking sideways at each other, sometimes with fatal results. Thus

also they drive away other enemies. (17. See, on our peewit, Mr. R. Carr in 'Land and Water,' Aug. 8th, 1868,

p. 46. In regard to Lobivanellus, see Jerdon's 'Birds of India,' vol. iii. p. 647, and Gould's 'Handbook of Birds

of Australia,' vol. ii. p. 220. For the Hoplopterus, see Mr. Allen in the 'Ibis,' vol. v. 1863, p. 156.)

The season of love is that of battle; but the males of some birds, as of the gamefowl and ruff, and even the

young males of the wild turkey and grouse (18. Audubon, 'Ornithological Biography,' vol. ii. p. 492; vol. i.

pp. 413.), are ready to fight whenever they meet. The presence of the female is the teterrima belli causa. The

Bengali baboos make the pretty little males of the amadavat (Estrelda amandava) fight together by placing

three small cages in a row, with a female in the middle; after a little time the two males are turned loose, and

immediately a desperate battle ensues. (19. Mr. Blyth, 'Land and Water,' 1867, p. 212.) When many males

congregate at the same appointed spot and fight together, as in the case of grouse and various other birds,

they are generally attended by the females (20. Richardson on Tetrao umbellus, 'Fauna Bor. Amer.: Birds,'

1831, p. 343. L. Lloyd, 'Game Birds of Sweden,' 1867, pp. 22, 79, on the capercailzie and blackcock.

Brehm, however, asserts ('Thierleben,' B. iv. s. 352) that in Germany the greyhens do not generally attend

the Balzen of the blackcocks, but this is an exception to the common rule; possibly the hens may lie hidden

in the surrounding bushes, as is known to be the case with the grayhens in Scandinavia, and with other

species in N. America.), which afterwards pair with the victorious combatants. But in some cases the pairing

precedes instead of succeeding the combat: thus according to Audubon (21. 'Ornithological Biography,' vol.

ii. p. 275.), several males of the Virginian goatsucker (Caprimulgus virgianus) "court, in a highly

entertaining manner the female, and no sooner has she made her choice, than her approved gives chase to all

intruders, and drives them beyond his dominions." Generally the males try to drive away or kill their rivals

before they pair. It does not, however, appear that the females invariably prefer the victorious males. I have

indeed been assured by Dr. W. Kovalevsky that the female capercailzie sometimes steals away with a young

male who has not dared to enter the arena with the older cocks, in the same manner as occasionally happens

with the does of the reddeer in Scotland. When two males contend in presence of a single female, the victor,

no doubt, commonly gains his desire; but some of these battles are caused by wandering males trying to

distract the peace of an already mated pair. (22. Brehm, 'Thierleben,' etc., B. iv. 1867, p. 990. Audubon,

Even with the most pugnacious species it is probable that the pairing does not depend exclusively on the mere

strength and courage of the male; for such males are generally decorated with various ornaments, which often

become more brilliant during the breedingseason, and which are sedulously displayed before the females.

The males also endeavour to charm or excite their mates by lovenotes, songs, and antics; and the courtship

is, in many instances, a prolonged affair. Hence it is not probable that the females are indifferent to the

charms of the opposite sex, or that they are invariably compelled to yield to the victorious males. It is more

probable that the females are excited, either before or after the conflict, by certain males, and thus

unconsciously prefer them. In the case of Tetrao umbellus, a good observer (23. 'Land and Water,' July 25,

1868, p. 14.) goes so far as to believe that the battles of the male "are all a sham, performed to show

themselves to the greatest advantage before the admiring females who assemble around; for I have never

been able to find a maimed hero, and seldom more than a broken feather." I shall have to recur to this subject,

but I may here add that with the Tetrao cupido of the United States, about a score of males assemble at a

particular spot, and, strutting about, make the whole air resound with their extraordinary noises. At the first

answer from a female the males begin to fight furiously, and the weaker give way; but then, according to

Audubon, both the victors and vanquished search for the female, so that the females must either then exert a

choice, or the battle must be renewed. So, again, with one of the fieldstarlings of the United States

(Sturnella ludoviciana) the males engage in fierce conflicts, "but at the sight of a female they all fly after her

as if mad." (24. Audubon's 'Ornithological Biography;' on Tetrao cupido, vol. ii. p. 492; on the Sturnus, vol.

With birds the voice serves to express various emotions, such as distress, fear, anger, triumph, or mere

happiness. It is apparently sometimes used to excite terror, as in the case of the hissing noise made by some

nestlingbirds. Audubon (25. 'Ornithological Biography,' vol. v. p. 601.), relates that a nightheron (Ardea

nycticorax, Linn.), which he kept tame, used to hide itself when a cat approached, and then "suddenly start up

uttering one of the most frightful cries, apparently enjoying the cat's alarm and flight." The common domestic

cock clucks to the hen, and the hen to her chickens, when a dainty morsel is found. The hen, when she has

laid an egg, "repeats the same note very often, and concludes with the sixth above, which she holds for a

longer time" (26. The Hon. Daines Barrington, 'Philosophical Transactions,' 1773, p. 252.); and thus she

expresses her joy. Some social birds apparently call to each other for aid; and as they flit from tree to tree, the

flock is kept together by chirp answering chirp. During the nocturnal migrations of geese and other

waterfowl, sonorous clangs from the van may be heard in the darkness overhead, answered by clangs in the

rear. Certain cries serve as danger signals, which, as the sportsman knows to his cost, are understood by the

same species and by others. The domestic cock crows, and the hummingbird chirps, in triumph over a

defeated rival. The true song, however, of most birds and various strange cries are chiefly uttered during the

breeding season, and serve as a charm, or merely as a callnote, to the other sex.

Naturalists are much divided with respect to the object of the singing of birds. Few more careful observers

ever lived than Montagu, and he maintained that the "males of songbirds and of many others do not in

general search for the female, but, on the contrary, their business in the spring is to perch on some

conspicuous spot, breathing out their full and armorous notes, which, by instinct, the female knows, and

repairs to the spot to choose her mate." (27. 'Ornithological Dictionary,' 1833, p. 475.) Mr. Jenner Weir

informs me that this is certainly the case with the nightingale. Bechstein, who kept birds during his whole

life, asserts, "that the female canary always chooses the best singer, and that in a state of nature the female

finch selects that male out of a hundred whose notes please her most." (28. 'Naturgeschichte der Stubenvogel,'

1840, s. 4. Mr. Harrison Weir likewise writes to me:"I am informed that the best singing males generally

get a mate first, when they are bred in the same room.") There can be no doubt that birds closely attend to

each other's song. Mr. Weir has told me of the case of a bullfinch which had been taught to pipe a German

waltz, and who was so good a performer that he cost ten guineas; when this bird was first introduced into a

room where other birds were kept and he began to sing, all the others, consisting of about twenty linnets and

canaries, ranged themselves on the nearest side of their cages, and listened with the greatest interest to the

new performer. Many naturalists believe that the singing of birds is almost exclusively "the effect of rivalry

and emulation," and not for the sake of charming their mates. This was the opinion of Daines Barrington and

White of Selborne, who both especially attended to this subject. (29. 'Philosophical Transactions,' 1773, p.

263. White's 'Natural History of Selborne,' 1825, vol. i. p. 246.) Barrington, however, admits that "superiority

in song gives to birds an amazing ascendancy over others, as is well known to bird catchers."

It is certain that there is an intense degree of rivalry between the males in their singing. Birdfanciers match

their birds to see which will sing longest; and I was told by Mr. Yarrell that a firstrate bird will sometimes

sing till he drops down almost dead, or according to Bechstein (30. 'Naturgesch. der Stubenvogel,' 1840, s.

252.), quite dead from rupturing a vessel in the lungs. Whatever the cause may be, male birds, as I hear from

Mr. Weir, often die suddenly during the season of song. That the habit of singing is sometimes quite

independent of love is clear, for a sterile, hybrid canarybird has been described (31. Mr. Bold, 'Zoologist,'

184344, p. 659.) as singing whilst viewing itself in a mirror, and then dashing at its own image; it likewise

attacked with fury a female canary, when put into the same cage. The jealousy excited by the act of singing is

constantly taken advantage of by birdcatchers; a male, in good song, is hidden and protected, whilst a

stuffed bird, surrounded by limed twigs, is exposed to view. In this manner, as Mr. Weir informs me, a man

has in the course of a single day caught fifty, and in one instance, seventy, male chaffinches. The power and

inclination to sing differ so greatly with birds that although the price of an ordinary male chaffinch is only

sixpence, Mr. Weir saw one bird for which the birdcatcher asked three pounds; the test of a really good

singer being that it will continue to sing whilst the cage is swung round the owner's head.

That male birds should sing from emulation as well as for charming the female, is not at all incompatible; and

it might have been expected that these two habits would have concurred, like those of display and pugnacity.

Some authors, however, argue that the song of the male cannot serve to charm the female, because the

females of some few species, such as of the canary, robin, lark, and bullfinch, especially when in a state of

widowhood, as Bechstein remarks, pour forth fairly melodious strains. In some of these cases the habit of

singing may be in part attributed to the females having been highly fed and confined (32. D. Barrington,

'Philosophical Transactions,' 1773, p. 262. Bechstein, 'Stubenvogel,' 1840, s. 4.), for this disturbs all the

functions connected with the reproduction of the species. Many instances have already been given of the

partial transference of secondary masculine characters to the female, so that it is not at all surprising that the

females of some species should possess the power of song. It has also been argued, that the song of the male

cannot serve as a charm, because the males of certain species, for instance of the robin, sing during the

autumn. (33. This is likewise the case with the waterouzel; see Mr. Hepburn in the 'Zoologist,' 184546, p.

1068.) But nothing is more common than for animals to take pleasure in practising whatever instinct they

follow at other times for some real good. How often do we see birds which fly easily, gliding and sailing

through the air obviously for pleasure? The cat plays with the captured mouse, and the cormorant with the

captured fish. The weaverbird (Ploceus), when confined in a cage, amuses itself by neatly weaving blades of

grass between the wires of its cage. Birds which habitually fight during the breedingseason are generally

ready to fight at all times; and the males of the capercailzie sometimes hold their Balzen or leks at the usual

place of assemblage during the autumn. (34. L. Lloyd, 'Game Birds of Sweden,' 1867, p. 25.) Hence it is not

at all surprising that male birds should continue singing for their own amusement after the season for

As shewn in a previous chapter, singing is to a certain extent an art, and is much improved by practice. Birds

can be taught various tunes, and even the unmelodious sparrow has learnt to sing like a linnet. They acquire

the song of their foster parents (35. Barrington, ibid. p. 264, Bechstein, ibid. s. 5.), and sometimes that of

their neighbours. (36. Dureau de la Malle gives a curious instance ('Annales des Sc. Nat.' 3rd series, Zoolog.,

tom. x. p. 118) of some wild blackbirds in his garden in Paris, which naturally learnt a republican air from a

caged bird.) All the common songsters belong to the Order of Insessores, and their vocal organs are much

more complex than those of most other birds; yet it is a singular fact that some of the Insessores, such as

ravens, crows, and magpies, possess the proper apparatus (37. Bishop, in 'Todd's Cyclopaedia of Anatomy

and Physiology,' vol. iv. p. 1496.), though they never sing, and do not naturally modulate their voices to any

great extent. Hunter asserts (38. As stated by Barrington in 'Philosophical Transactions,' 1773, p. 262.) that

with the true songsters the muscles of the larynx are stronger in the males than in the females; but with this

slight exception there is no difference in the vocal organs of the two sexes, although the males of most

It is remarkable that only small birds properly sing. The Australian genus Menura, however, must be

excepted; for the Menura Alberti, which is about the size of a halfgrown turkey, not only mocks other birds,

but "its own whistle is exceedingly beautiful and varied." The males congregate and form "corroborying

places," where they sing, raising and spreading their tails like peacocks, and drooping their wings. (39.

Gould, 'Handbook to the Birds of Australia,' vol. i. 1865, pp. 308310. See also Mr. T.W. Wood in the

'Student,' April 1870, p. 125.) It is also remarkable that birds which sing well are rarely decorated with

brilliant colours or other ornaments. Of our British birds, excepting the bullfinch and goldfinch, the best

songsters are plaincoloured. The kingfisher, beeeater, roller, hoopoe, woodpeckers, etc., utter harsh cries;

and the brilliant birds of the tropics are hardly ever songsters. (40. See remarks to this effect in Gould's

'Introduction to the Trochilidae,' 1861, p. 22.) Hence bright colours and the power of song seem to replace

each other. We can perceive that if the plumage did not vary in brightness, or if bright colours were

dangerous to the species, other means would be employed to charm the females; and melody of voice offers

In some birds the vocal organs differ greatly in the two sexes. In the Tetrao cupido (Fig. 39) the male has two

bare, orangecoloured sacks, one on each side of the neck; and these are largely inflated when the male,

during the breedingseason, makes his curious hollow sound, audible at a great distance. Audubon proved

that the sound was intimately connected with this apparatus (which reminds us of the airsacks on each side

of the mouth of certain male frogs), for he found that the sound was much diminished when one of the sacks

of a tame bird was pricked, and when both were pricked it was altogether stopped. The female has "a

somewhat similar, though smaller naked space of skin on the neck; but this is not capable of inflation." (41.

'The Sportsman and Naturalist in Canada,' by Major W. Ross King, 1866, pp. 144146. Mr. T.W. Wood

gives in the 'Student' (April 1870, p. 116) an excellent account of the attitude and habits of this bird during its

courtship. He states that the eartufts or neckplumes are erected, so that they meet over the crown of the

head. See his drawing, Fig. 39.) The male of another kind of grouse (Tetrao urophasianus), whilst courting

the female, has his "bare yellow oesophagus inflated to a prodigious size, fully half as large as the body"; and

he then utters various grating, deep, hollow tones. With his neckfeathers erect, his wings lowered, and

buzzing on the ground, and his long pointed tail spread out like a fan, he displays a variety of grotesque

attitudes. The oesophagus of the female is not in any way remarkable. (42. Richardson, 'Fauna Bor.

It seems now well made out that the great throat pouch of the European male bustard (Otis tarda), and of at

least four other species, does not, as was formerly supposed, serve to hold water, but is connected with the

utterance during the breedingseason of a peculiar sound resembling "oak." (43. The following papers have

been lately written on this subject: Prof. A. Newton, in the 'Ibis,' 1862, p. 107; Dr. Cullen, ibid. 1865, p. 145;

Mr. Flower, in 'Proc. Zool. Soc.' 1865, p. 747; and Dr. Murie, in 'Proc. Zool. Soc.' 1868, p. 471. In this latter

paper an excellent figure is given of the male Australian Bustard in full display with the sack distended. It is a

singular fact that the sack is not developed in all the males of the same species.) A crowlike bird inhabiting

South America (see Cephalopterus ornatus, Fig. 40) is called the umbrellabird, from its immense top knot,

formed of bare white quills surmounted by darkblue plumes, which it can elevate into a great dome no less

than five inches in diameter, covering the whole head. This bird has on its neck a long, thin, cylindrical fleshy

appendage, which is thickly clothed with scalelike blue feathers. It probably serves in part as an ornament,

but likewise as a resounding apparatus; for Mr. Bates found that it is connected "with an unusual

development of the trachea and vocal organs." It is dilated when the bird utters its singularly deep, loud and

long sustained fluty note. The head crest and neckappendage are rudimentary in the female. (44. Bates,

'The Naturalist on the Amazons,' 1863, vol. ii. p. 284; Wallace, in 'Proceedings, Zoological Society,' 1850, p.

206. A new species, with a still larger neckappendage (C. penduliger), has lately been discovered, see 'Ibis,'

The vocal organs of various webfooted and wading birds are extraordinarily complex, and differ to a certain

extent in the two sexes. In some cases the trachea is convoluted, like a French horn, and is deeply embedded

in the sternum. In the wild swan (Cygnus ferus) it is more deeply embedded in the adult male than in the

adult female or young male. In the male Merganser the enlarged portion of the trachea is furnished with an

additional pair of muscles. (45. Bishop, in Todd's 'Cyclopaedia of Anatomy and Physiology,' vol. iv. p. 1499.)

In one of the ducks, however, namely Anas punctata, the bony enlargement is only a little more developed in

the male than in the female. (46. Prof. Newton, 'Proc. Zoolog. Soc.' 1871, p. 651.) But the meaning of these

differences in the trachea of the two sexes of the Anatidae is not understood; for the male is not always the

more vociferous; thus with the common duck, the male hisses, whilst the female utters a loud quack. (47. The

spoonbill (Platalea) has its trachea convoluted into a figure of eight, and yet this bird (Jerdon, 'Birds of India,'

vol. iii. p. 763) is mute; but Mr. Blyth informs me that the convolutions are not constantly present, so that

perhaps they are now tending towards abortion.) In both sexes of one of the cranes (Grus virgo) the trachea

penetrates the sternum, but presents "certain sexual modifications." In the male of the black stork there is also

a wellmarked sexual difference in the length and curvature of the bronchi. (48. 'Elements of Comparative

Anatomy,' by R. Wagner, Eng. translat. 1845, p. 111. With respect to the swan, as given above, Yarrell's

'History of British Birds,' 2nd edition, 1845, vol. iii. p. 193.) Highly important structures have, therefore, in

It is often difficult to conjecture whether the many strange cries and notes uttered by male birds during the

breedingseason serve as a charm or merely as a call to the female. The soft cooing of the turtledove and of

many pigeons, it may be presumed, pleases the female. When the female of the wild turkey utters her call in

the morning, the male answers by a note which differs from the gobbling noise made, when with erected

feathers, rustling wings and distended wattles, he puffs and struts before her. (49. C.L. Bonaparte, quoted in

the 'Naturalist Library: Birds,' vol. xiv. p. 126.) The spel of the blackcock certainly serves as a call to the

female, for it has been known to bring four or five females from a distance to a male under confinement; but

as the blackcock continues his spel for hours during successive days, and in the case of the capercailzie

"with an agony of passion," we are led to suppose that the females which are present are thus charmed. (50.

L. Lloyd, 'The Game Birds of Sweden,' etc., 1867, pp. 22, 81.) The voice of the common rook is known to

alter during the breedingseason, and is therefore in some way sexual. (51. Jenner, 'Philosophical

Transactions,' 1824, p. 20.) But what shall we say about the harsh screams of, for instance, some kinds of

macaws; have these birds as bad taste for musical sounds as they apparently have for colour, judging by the

inharmonious contrast of their bright yellow and blue plumage? It is indeed possible that without any

advantage being thus gained, the loud voices of many male birds may be the result of the inherited effects of

the continued use of their vocal organs when excited by the strong passions of love, jealousy and rage; but to

We have as yet spoken only of the voice, but the males of various birds practise, during their courtship, what

may be called instrumental music. Peacocks and Birds of Paradise rattle their quills together. Turkeycocks

scrape their wings against the ground, and some kinds of grouse thus produce a buzzing sound. Another

North American grouse, the Tetrao umbellus, when with his tail erect, his ruffs displayed, "he shows off his

finery to the females, who lie hid in the neighbourhood," drums by rapidly striking his wings together above

his back, according to Mr. R. Haymond, and not, as Audubon thought, by striking them against his sides. The

sound thus produced is compared by some to distant thunder, and by others to the quick roll of a drum. The

female never drums, "but flies directly to the place where the male is thus engaged." The male of the

Kalijpheasant, in the Himalayas, often makes a singular drumming noise with his wings, not unlike the

sound produced by shaking a stiff piece of cloth." On the west coast of Africa the little blackweavers

(Ploceus?) congregate in a small party on the bushes round a small open space, and sing and glide through the

air with quivering wings, "which make a rapid whirring sound like a child's rattle." One bird after another

thus performs for hours together, but only during the courtingseason. At this season, and at no other time,

the males of certain nightjars (Caprimulgus) make a strange booming noise with their wings. The various

species of woodpeckers strike a sonorous branch with their beaks, with so rapid a vibratory movement that

"the head appears to be in two places at once." The sound thus produced is audible at a considerable distance

but cannot be described; and I feel sure that its source would never be conjectured by any one hearing it for

the first time. As this jarring sound is made chiefly during the breedingseason, it has been considered as a

lovesong; but it is perhaps more strictly a love call. The female, when driven from her nest, has been

observed thus to call her mate, who answered in the same manner and soon appeared. Lastly, the male

hoopoe (Upupa epops) combines vocal and instrumental music; for during the breedingseason this bird, as

Mr. Swinhoe observed, first draws in air, and then taps the end of its beak perpendicularly down against a

stone or the trunk of a tree, "when the breath being forced down the tubular bill produces the correct sound."

If the beak is not thus struck against some object, the sound is quite different. Air is at the same time

swallowed, and the oesophagus thus becomes much swollen; and this probably acts as a resonator, not only

with the hoopoe, but with pigeons and other birds. (52. For the foregoing facts see, on Birds of Paradise,

Brehm, 'Thierleben,' Band iii. s. 325. On Grouse, Richardson, 'Fauna Bor. Americ.: Birds,' pp. 343 and 359;

Major W. Ross King, 'The Sportsman in Canada,' 1866, p. 156; Mr. Haymond, in Prof. Cox's 'Geol. Survey

of Indiana,' p. 227; Audubon, 'American Ornitholog. Biograph.' vol. i. p. 216. On the Kalijpheasant, Jerdon,

'Birds of India,' vol. iii. p. 533. On the Weavers, Livingstone's 'Expedition to the Zambesi,' 1865, p. 425. On

Woodpeckers, Macgillivray, 'Hist. of British Birds,' vol. iii. 1840, pp. 84, 88, 89, and 95. On the Hoopoe, Mr.

Swinhoe, in 'Proc. Zoolog. Soc.' June 23, 1863 and 1871, p. 348. On the Nightjar, Audubon, ibid. vol. ii. p.

255, and 'American Naturalist,' 1873, p. 672. The English Nightjar likewise makes in the spring a curious

[Fig. 41. Outer tailfeather of Scolopax gallinago (from 'Proc. Zool. Soc.' 1858).

In the foregoing cases sounds are made by the aid of structures already present and otherwise necessary; but

in the following cases certain feathers have been specially modified for the express purpose of producing

sounds. The drumming, bleating, neighing, or thundering noise (as expressed by different observers) made by

the common snipe (Scolopax gallinago) must have surprised every one who has ever heard it. This bird,

during the pairingseason, flies to "perhaps a thousand feet in height," and after zigzagging about for a time

descends to the earth in a curved line, with outspread tail and quivering pinions, and surprising velocity. The

sound is emitted only during this rapid descent. No one was able to explain the cause until M. Meves

observed that on each side of the tail the outer feathers are peculiarly formed (Fig. 41), having a stiff

sabreshaped shaft with the oblique barbs of unusual length, the outer webs being strongly bound together.

He found that by blowing on these feathers, or by fastening them to a long thin stick and waving them rapidly

through the air, he could reproduce the drumming noise made by the living bird. Both sexes are furnished

with these feathers, but they are generally larger in the male than in the female, and emit a deeper note. In

some species, as in S. frenata (Fig. 42), four feathers, and in S. javensis (Fig. 43), no less than eight on each

side of the tail are greatly modified. Different tones are emitted by the feathers of the different species when

waved through the air; and the Scolopax Wilsonii of the United States makes a switching noise whilst

descending rapidly to the earth. (53. See M. Meves' interesting paper in 'Proc. Zool. Soc.' 1858, p. 199. For

the habits of the snipe, Macgillivray, 'History of British Birds,' vol. iv. p. 371. For the American snipe, Capt.

[Fig. 44. Primary wingfeather of a Hummingbird, the Selasphorus platycercus (from a sketch by Mr.

Salvin). Upper figure, that of male; lower figure, corresponding feather of female.]

In the male of the Chamaepetes unicolor (a large gallinaceous bird of America), the first primary

wingfeather is arched towards the tip and is much more attenuated than in the female. In an allied bird, the

Penelope nigra, Mr. Salvin observed a male, which, whilst it flew downwards "with outstretched wings, gave

forth a kind of crashing rushing noise," like the falling of a tree. (54. Mr. Salvin, in 'Proceedings, Zoological

Society,' 1867, p. 160. I am much indebted to this distinguished ornithologist for sketches of the feathers of

the Chamaepetes, and for other information.) The male alone of one of the Indian bustards (Sypheotides

auritus) has its primary wingfeathers greatly acuminated; and the male of an allied species is known to make

a humming noise whilst courting the female. (55. Jerdon, 'Birds of India,' vol. iii. pp. 618, 621.) In a widely

different group of birds, namely Hummingbirds, the males alone of certain kinds have either the shafts of

their primary wingfeathers broadly dilated, or the webs abruptly excised towards the extremity. The male,

for instance, of Selasphorus platycercus, when adult, has the first primary wingfeather (Fig. 44), thus

excised. Whilst flying from flower to flower he makes "a shrill, almost whistling noise" (56. Gould,

'Introduction to the Trochilidae,' 1861, p. 49. Salvin, 'Proceedings, Zoological Society,' 1867, p. 160.); but it

[Fig. 45. Secondary wingfeathers of Pipra deliciosa (from Mr. Sclater, in 'Proc. Zool. Soc.' 1860). The three

upper feathers, a, b, c, from the male; the three lower corresponding feathers, d, e, f, from the female. a and d,

fifth secondary wingfeather of male and female, upper surface. b and e, sixth secondary, upper surface. c

Lastly, in several species of a subgenus of Pipra or Manakin, the males, as described by Mr. Sclater, have

their SECONDARY wingfeathers modified in a still more remarkable manner. In the brilliantlycoloured P.

deliciosa the first three secondaries are thickstemmed and curved towards the body; in the fourth and fifth

(Fig. 45, a) the change is greater; and in the sixth and seventh (b, c) the shaft "is thickened to an extraordinary

degree, forming a solid horny lump." The barbs also are greatly changed in shape, in comparison with the

corresponding feathers (d, e, f) in the female. Even the bones of the wing, which support these singular

feathers in the male, are said by Mr. Fraser to be much thickened. These little birds make an extraordinary

noise, the first "sharp note being not unlike the crack of a whip." (57. Sclater, in 'Proceedings, Zoological

Society,' 1860, p. 90, and in 'Ibis,' vol. iv. 1862, p. 175. Also Salvin, in 'Ibis,' 1860, p. 37.)

The diversity of the sounds, both vocal and instrumental, made by the males of many birds during the

breedingseason, and the diversity of the means for producing such sounds, are highly remarkable. We thus

gain a high idea of their importance for sexual purposes, and are reminded of the conclusion arrived at as to

insects. It is not difficult to imagine the steps by which the notes of a bird, primarily used as a mere call or for

some other purpose, might have been improved into a melodious love song. In the case of the modified

feathers, by which the drumming, whistling, or roaring noises are produced, we know that some birds during

their courtship flutter, shake, or rattle their unmodified feathers together; and if the females were led to select

the best performers, the males which possessed the strongest or thickest, or most attenuated feathers, situated

on any part of the body, would be the most successful; and thus by slow degrees the feathers might be

modified to almost any extent. The females, of course, would not notice each slight successive alteration in

shape, but only the sounds thus produced. It is a curious fact that in the same class of animals, sounds so

different as the drumming of the snipe's tail, the tapping of the woodpecker's beak, the harsh trumpetlike cry

of certain waterfowl, the cooing of the turtledove, and the song of the nightingale, should all be pleasing to

the females of the several species. But we must not judge of the tastes of distinct species by a uniform

standard; nor must we judge by the standard of man's taste. Even with man, we should remember what

discordant noises, the beating of tomtoms and the shrill notes of reeds, please the ears of savages. Sir S.

Baker remarks (58. 'The Nile Tributaries of Abyssinia,' 1867, p. 203.), that "as the stomach of the Arab

prefers the raw meat and reeking liver taken hot from the animal, so does his ear prefer his equally coarse and

The curious love gestures of some birds have already been incidentally noticed; so that little need here be

added. In Northern America large numbers of a grouse, the Tetrao phasianellus, meet every morning during

the breedingseason on a selected level spot, and here they run round and round in a circle of about fifteen or

twenty feet in diameter, so that the ground is worn quite bare, like a fairyring. In these Partridgedances, as

they are called by the hunters, the birds assume the strangest attitudes, and run round, some to the left and

some to the right. Audubon describes the males of a heron (Ardea herodias) as walking about on their long

legs with great dignity before the females, bidding defiance to their rivals. With one of the disgusting

carrionvultures (Cathartes jota) the same naturalist states that "the gesticulations and parade of the males at

the beginning of the loveseason are extremely ludicrous." Certain birds perform their loveantics on the

wing, as we have seen with the black African weaver, instead of on the ground. During the spring our little

whitethroat (Sylvia cinerea) often rises a few feet or yards in the air above some bush, and "flutters with a

fitful and fantastic motion, singing all the while, and then drops to its perch." The great English bustard

throws himself into indescribably odd attitudes whilst courting the female, as has been figured by Wolf. An

allied Indian bustard (Otis bengalensis) at such times "rises perpendicularly into the air with a hurried

flapping of his wings, raising his crest and puffing out the feathers of his neck and breast, and then drops to

the ground;" he repeats this manoeuvre several times, at the same time humming in a peculiar tone. Such

females as happen to be near "obey this saltatory summons," and when they approach he trails his wings and

spreads his tail like a turkeycock. (59. For Tetrao phasianellus, see Richardson, 'Fauna, Bor. America,' p.

361, and for further particulars Capt. Blakiston, 'Ibis,' 1863, p. 125. For the Cathartes and Ardea, Audubon,

'Ornithological Biography,' vol. ii. p. 51, and vol. iii. p. 89. On the Whitethroat, Macgillivray, 'History of

British Birds,' vol. ii. p. 354. On the Indian Bustard, Jerdon, 'Birds of India,' vol. iii. p. 618.)

But the most curious case is afforded by three allied genera of Australian birds, the famous

Bowerbirds,no doubt the codescendants of some ancient species which first acquired the strange instinct

of constructing bowers for performing their loveantics. The bowers (Fig. 46), which, as we shall hereafter

see, are decorated with feathers, shells, bones, and leaves, are built on the ground for the sole purpose of

courtship, for their nests are formed in trees. Both sexes assist in the erection of the bowers, but the male is

the principal workman. So strong is this instinct that it is practised under confinement, and Mr. Strange has

described (60. Gould, 'Handbook to the Birds of Australia,' vol. i. pp. 444, 449, 455. The bower of the Satin

Bowerbird may be seen in the Zoological Society's Gardens, Regent's Park.) the habits of some Satin

Bowerbirds which he kept in an aviary in New South Wales. "At times the male will chase the female all

over the aviary, then go to the bower, pick up a gay feather or a large leaf, utter a curious kind of note, set all

his feathers erect, run round the bower and become so excited that his eyes appear ready to start from his

bead; he continues opening first one wing then the other, uttering a low, whistling note, and, like the domestic

cock, seems to be picking up something from the ground, until at last the female goes gently towards him."

Captain Stokes has described the habits and "playhouses" of another species, the Great Bowerbird, which

was seen "amusing itself by flying backwards and forwards, taking a shell alternately from each side, and

carrying it through the archway in its mouth." These curious structures, formed solely as halls of assemblage,

where both sexes amuse themselves and pay their court, must cost the birds much labour. The bower, for

instance, of the Fawnbreasted species, is nearly four feet in length, eighteen inches in height, and is raised

I will first discuss the cases in which the males are ornamented either exclusively or in a much higher degree

than the females, and in a succeeding chapter those in which both sexes are equally ornamented, and finally

the rare cases in which the female is somewhat more brightly coloured than the male. As with the artificial

ornaments used by savage and civilised men, so with the natural ornaments of birds, the head is the chief seat

of decoration. (61. See remarks to this effect, on the 'Feeling of Beauty among Animals,' by Mr. J. Shaw, in

the 'Athenaeum,' Nov. 24th, 1866, p. 681.) The ornaments, as mentioned at the commencement of this

chapter, are wonderfully diversified. The plumes on the front or back of the head consist of variouslyshaped

feathers, sometimes capable of erection or expansion, by which their beautiful colours are fully displayed.

Elegant eartufts (Fig. 39) are occasionally present. The head is sometimes covered with velvety down, as

with the pheasant; or is naked and vividly coloured. The throat, also, is sometimes ornamented with a beard,

wattles, or caruncles. Such appendages are generally brightly coloured, and no doubt serve as ornaments,

though not always ornamental in our eyes; for whilst the male is in the act of courting the female, they often

swell and assume vivid tints, as in the male turkey. At such times the fleshy appendages about the head of the

male Tragopan pheasant (Ceriornis Temminckii) swell into a large lappet on the throat and into two horns,

one on each side of the splendid topknot; and these are then coloured of the most intense blue which I have

ever beheld. (62. See Dr. Murie's account with coloured figures in 'Proceedings, Zoological Society,' 1872, p.

730.) The African hornbill (Bucorax abyssinicus) inflates the scarlet bladderlike wattle on its neck, and with

its wings drooping and tail expanded "makes quite a grand appearance." (63. Mr. Monteiro, 'Ibis,' vol. iv.

1862, p. 339.) Even the iris of the eye is sometimes more brightlycoloured in the male than in the female;

and this is frequently the case with the beak, for instance, in our common blackbird. In Buceros corrugatus,

the whole beak and immense casque are coloured more conspicuously in the male than in the female; and

"the oblique grooves upon the sides of the lower mandible are peculiar to the male sex." (64. 'Land and

The head, again, often supports fleshy appendages, filaments, and solid protuberances. These, if not common

to both sexes, are always confined to the males. The solid protuberances have been described in detail by Dr.

W. Marshall (65. 'Ueber die Schadelhocker,' etc., 'Niederland. Archiv. fur Zoologie,' B. I. Heft 2, 1872.), who

shews that they are formed either of cancellated bone coated with skin, or of dermal and other tissues. With

mammals true horns are always supported on the frontal bones, but with birds various bones have been

modified for this purpose; and in species of the same group the protuberances may have cores of bone, or be

quite destitute of them, with intermediate gradations connecting these two extremes. Hence, as Dr. Marshall

justly remarks, variations of the most different kinds have served for the development through sexual

selection of these ornamental appendages. Elongated feathers or plumes spring from almost every part of the

body. The feathers on the throat and breast are sometimes developed into beautiful ruffs and collars. The

tailfeathers are frequently increased in length; as we see in the tailcoverts of the peacock, and in the tail

itself of the Argus pheasant. With the peacock even the bones of the tail have been modified to support the

heavy tail coverts. (66. Dr. W. Marshall, 'Uber den Vogelschwanz,' ibid. B. I. Heft 2, 1872.) The body of the

Argus is not larger than that of a fowl; yet the length from the end of the beak to the extremity of the tail is no

less than five feet three inches (67. Jardine's 'Naturalist Library: Birds,' vol. xiv. p. 166.), and that of the

beautifully ocellated secondary wing feathers nearly three feet. In a small African nightjar (Cosmetornis

vexillarius) one of the primary wingfeathers, during the breedingseason, attains a length of twentysix

inches, whilst the bird itself is only ten inches in length. In another closelyallied genus of nightjars, the

shafts of the elongated wingfeathers are naked, except at the extremity, where there is a disc. (68. Sclater, in

the 'Ibis,' vol. vi. 1864, p. 114; Livingstone, 'Expedition to the Zambesi,' 1865, p. 66.) Again, in another

genus of nightjars, the tailfeathers are even still more prodigiously developed. In general the feathers of the

tail are more often elongated than those of the wings, as any great elongation of the latter impedes flight. We

thus see that in closelyallied birds ornaments of the same kind have been gained by the males through the

It is a curious fact that the feathers of species belonging to very distinct groups have been modified in almost

exactly the same peculiar manner. Thus the wingfeathers in one of the abovementioned nightjars are bare

along the shaft, and terminate in a disc; or are, as they are sometimes called, spoon or racketshaped.

Feathers of this kind occur in the tail of a motmot (Eumomota superciliaris), of a kingfisher, finch,

hummingbird, parrot, several Indian drongos (Dicrurus and Edolius, in one of which the disc stands

vertically), and in the tail of certain birds of paradise. In these latter birds, similar feathers, beautifully

ocellated, ornament the head, as is likewise the case with some gallinaceous birds. In an Indian bustard

(Sypheotides auritus) the feathers forming the ear tufts, which are about four inches in length, also terminate

in discs. (69. Jerdon, 'Birds of India,' vol. iii. p. 620.) It is a most singular fact that the motmots, as Mr. Salvin

has clearly shewn (70. 'Proceedings, Zoological Society,' 1873, p. 429.), give to their tail feathers the

racketshape by biting off the barbs, and, further, that this continued mutilation has produced a certain

Again, the barbs of the feathers in various widelydistinct birds are filamentous or plumose, as with some

herons, ibises, birds of paradise, and Gallinaceae. In other cases the barbs disappear, leaving the shafts bare

from end to end; and these in the tail of the Paradisea apoda attain a length of thirtyfour inches (71. Wallace,

in 'Annals and Magazine of Natural History,' vol. xx. 1857, p. 416, and in his 'Malay Archipelago,' vol. ii.

1869, p. 390.): in P. Papuana (Fig. 47) they are much shorter and thin. Smaller feathers when thus denuded

appear like bristles, as on the breast of the turkeycock. As any fleeting fashion in dress comes to be admired

by man, so with birds a change of almost any kind in the structure or colouring of the feathers in the male

appears to have been admired by the female. The fact of the feathers in widely distinct groups having been

modified in an analogous manner no doubt depends primarily on all the feathers having nearly the same

structure and manner of development, and consequently tending to vary in the same manner. We often see a

tendency to analogous variability in the plumage of our domestic breeds belonging to distinct species. Thus

topknots have appeared in several species. In an extinct variety of the turkey, the topknot consisted of bare

quills surmounted with plumes of down, so that they somewhat resembled the racket shaped feathers above

described. In certain breeds of the pigeon and fowl the feathers are plumose, with some tendency in the shafts

to be naked. In the Sebastopol goose the scapular feathers are greatly elongated, curled, or even spirally

twisted, with the margins plumose. (72. See my work on 'The Variation of Animals and Plants under

In regard to colour, hardly anything need here be said, for every one knows how splendid are the tints of

many birds, and how harmoniously they are combined. The colours are often metallic and iridescent. Circular

spots are sometimes surrounded by one or more differently shaded zones, and are thus converted into ocelli.

Nor need much be said on the wonderful difference between the sexes of many birds. The common peacock

offers a striking instance. Female birds of paradise are obscurely coloured and destitute of all ornaments,

whilst the males are probably the most highly decorated of all birds, and in so many different ways that they

must be seen to be appreciated. The elongated and goldenorange plumes which spring from beneath the

wings of the Paradisea apoda, when vertically erected and made to vibrate, are described as forming a sort of

halo, in the centre of which the head "looks like a little emerald sun with its rays formed by the two plumes."

(73. Quoted from M. de Lafresnaye in 'Annals and Mag. of Natural History,' vol. xiii. 1854, p. 157: see also

Mr. Wallace's much fuller account in vol. xx. 1857, p. 412, and in his 'Malay Archipelago.'S) In another most

beautiful species the head is bald, "and of a rich cobalt blue, crossed by several lines of black velvety

Male hummingbirds (Figs. 48 and 49) almost vie with birds of paradise in their beauty, as every one will

admit who has seen Mr. Gould's splendid volumes, or his rich collection. It is very remarkable in how many

different ways these birds are ornamented. Almost every part of their plumage has been taken advantage of,

and modified; and the modifications have been carried, as Mr. Gould shewed me, to a wonderful extreme in

some species belonging to nearly every subgroup. Such cases are curiously like those which we see in our

fancy breeds, reared by man for the sake of ornament; certain individuals originally varied in one character,

and other individuals of the same species in other characters; and these have been seized on by man and much

augmentedas shewn by the tail of the fantail pigeon, the hood of the jacobin, the beak and wattle of the

carrier, and so forth. The sole difference between these cases is that in the one, the result is due to man's

selection, whilst in the other, as with humming birds, birds of paradise, etc., it is due to the selection by the

I will mention only one other bird, remarkable from the extreme contrast in colour between the sexes, namely

the famous bellbird (Chasmorhynchus niveus) of S. America, the note of which can be distinguished at the

distance of nearly three miles, and astonishes every one when first hearing it. The male is pure white, whilst

the female is duskygreen; and white is a very rare colour in terrestrial species of moderate size and

inoffensive habits. The male, also, as described by Waterton, has a spiral tube, nearly three inches in length,

which rises from the base of the beak. It is jetblack, dotted over with minute downy feathers. This tube can

be inflated with air, through a communication with the palate; and when not inflated hangs down on one side.

The genus consists of four species, the males of which are very distinct, whilst the females, as described by

Mr. Sclater in a very interesting paper, closely resemble each other, thus offering an excellent instance of the

common rule that within the same group the males differ much more from each other than do the females. In

a second species (C. nudicollis) the male is likewise snowwhite, with the exception of a large space of

naked skin on the throat and round the eyes, which during the breedingseason is of a fine green colour. In a

third species (C. tricarunculatus) the head and neck alone of the male are white, the rest of the body being

chestnutbrown, and the male of this species is provided with three filamentous projections half as long as

the bodyone rising from the base of the beak, and the two others from the corners of the mouth. (75. Mr.

Sclater, 'Intellectual Observer,' Jan. 1867. Waterton's 'Wanderings,' p. 118. See also Mr. Salvin's interesting

The coloured plumage and certain other ornaments of the adult males are either retained for life, or are

periodically renewed during the summer and breedingseason. At this same season the beak and naked skin

about the head frequently change colour, as with some herons, ibises, gulls, one of the bellbirds just noticed,

etc. In the white ibis, the cheeks, the inflatable skin of the throat, and the basal portion of the beak then

become crimson. (76. 'Land and Water,' 1867, p. 394.) In one of the rails, Gallicrex cristatus, a large red

caruncle is developed during this period on the head of the male. So it is with a thin horny crest on the beak

of one of the pelicans, P. erythrorhynchus; for, after the breeding season, these horny crests are shed, like

horns from the heads of stags, and the shore of an island in a lake in Nevada was found covered with these

Changes of colour in the plumage according to the season depend, firstly on a double annual moult, secondly

on an actual change of colour in the feathers themselves, and thirdly on their dullcoloured margins being

periodically shed, or on these three processes more or less combined. The shedding of the deciduary margins

may be compared with the shedding of their down by very young birds; for the down in most cases arises

from the summits of the first true feathers. (78. Nitzsch's 'Pterylography,' edited by P.L. Sclater, Ray Society,

With respect to the birds which annually undergo a double moult, there are, firstly, some kinds, for instance

snipes, swallowplovers (Glareolae), and curlews, in which the two sexes resemble each other, and do not

change colour at any season. I do not know whether the winter plumage is thicker and warmer than the

summer plumage, but warmth seems the most probable end attained of a double moult, where there is no

change of colour. Secondly, there are birds, for instance, certain species of Totanus and other Grallatores, the

sexes of which resemble each other, but in which the summer and winter plumage differ slightly in colour.

The difference, however, in these cases is so small that it can hardly be an advantage to them; and it may,

perhaps, be attributed to the direct action of the different conditions to which the birds are exposed during the

two seasons. Thirdly, there are many other birds the sexes of which are alike, but which are widely different

in their summer and winter plumage. Fourthly, there are birds the sexes of which differ from each other in

colour; but the females, though moulting twice, retain the same colours throughout the year, whilst the males

undergo a change of colour, sometimes a great one, as with certain bustards. Fifthly and lastly, there are birds

the sexes of which differ from each other in both their summer and winter plumage; but the male undergoes a

greater amount of change at each recurrent season than the femaleof which the ruff (Machetes pugnax)

With respect to the cause or purpose of the differences in colour between the summer and winter plumage,

this may in some instances, as with the ptarmigan (79. The brown mottled summer plumage of the ptarmigan

is of as much importance to it, as a protection, as the white winter plumage; for in Scandinavia during the

spring, when the snow has disappeared, this bird is known to suffer greatly from birds of prey, before it has

acquired its summer dress: see Wilhelm von Wright, in Lloyd, 'Game Birds of Sweden,' 1867, p. 125.), serve

during both seasons as a protection. When the difference between the two plumages is slight it may perhaps

be attributed, as already remarked, to the direct action of the conditions of life. But with many birds there can

hardly be a doubt that the summer plumage is ornamental, even when both sexes are alike. We may conclude

that this is the case with many herons, egrets, etc., for they acquire their beautiful plumes only during the

breedingseason. Moreover, such plumes, topknots, etc., though possessed by both sexes, are occasionally a

little more developed in the male than in the female; and they resemble the plumes and ornaments possessed

by the males alone of other birds. It is also known that confinement, by affecting the reproductive system of

male birds, frequently checks the development of their secondary sexual characters, but has no immediate

influence on any other characters; and I am informed by Mr. Bartlett that eight or nine specimens of the Knot

(Tringa canutus) retained their unadorned winter plumage in the Zoological Gardens throughout the year,

from which fact we may infer that the summer plumage, though common to both sexes, partakes of the nature

of the exclusively masculine plumage of many other birds. (80. In regard to the previous statements on

moulting, see, on snipes, etc., Macgillivray, 'Hist. Brit. Birds,' vol. iv. p. 371; on Glareolae, curlews, and

bustards, Jerdon, 'Birds of India,' vol. iii. pp. 615, 630, 683; on Totanus, ibid. p. 700; on the plumes of herons,

ibid. p. 738, and Macgillivray, vol. iv. pp. 435 and 444, and Mr. Stafford Allen, in the 'Ibis,' vol. v. 1863, p.

From the foregoing facts, more especially from neither sex of certain birds changing colour during either

annual moult, or changing so slightly that the change can hardly be of any service to them, and from the

females of other species moulting twice yet retaining the same colours throughout the year, we may conclude

that the habit of annually moulting twice has not been acquired in order that the male should assume an

ornamental character during the breedingseason; but that the double moult, having been originally acquired

for some distinct purpose, has subsequently been taken advantage of in certain cases for gaining a nuptial

It appears at first sight a surprising circumstance that some closely allied species should regularly undergo a

double annual moult, and others only a single one. The ptarmigan, for instance, moults twice or even thrice in

the year, and the blackcock only once: some of the splendidly coloured honeysuckers (Nectariniae) of India

and some subgenera of obscurely coloured pipits (Anthus) have a double, whilst others have only a single

annual moult. (81. On the moulting of the ptarmigan, see Gould's 'Birds of Great Britain.' On the

honeysuckers, Jerdon, 'Birds of India,' vol. i. pp. 359, 365, 369. On the moulting of Anthus, see Blyth, in

'Ibis,' 1867, p. 32.) But the gradations in the manner of moulting, which are known to occur with various

birds, shew us how species, or whole groups, might have originally acquired their double annual moult, or

having once gained the habit, have again lost it. With certain bustards and plovers the vernal moult is far from

complete, some feathers being renewed, and some changed in colour. There is also reason to believe that with

certain bustards and raillike birds, which properly undergo a double moult, some of the older males retain

their nuptial plumage throughout the year. A few highly modified feathers may merely be added during the

spring to the plumage, as occurs with the discformed tailfeathers of certain drongos (Bhringa) in India, and

with the elongated feathers on the back, neck, and crest of certain herons. By such steps as these, the vernal

moult might be rendered more and more complete, until a perfect double moult was acquired. Some of the

birds of paradise retain their nuptial feathers throughout the year, and thus have only a single moult; others

cast them directly after the breedingseason, and thus have a double moult; and others again cast them at this

season during the first year, but not afterwards; so that these latter species are intermediate in their manner of

moulting. There is also a great difference with many birds in the length of time during which the two annual

plumages are retained; so that the one might come to be retained for the whole year, and the other completely

lost. Thus in the spring Machetes pugnax retains his ruff for barely two months. In Natal the male

widowbird (Chera progne) acquires his fine plumage and long tailfeathers in December or January, and

loses them in March; so that they are retained only for about three months. Most species, which undergo a

double moult, keep their ornamental feathers for about six months. The male, however, of the wild Gallus

bankiva retains his neckhackles for nine or ten months; and when these are cast off, the underlying black

feathers on the neck are fully exposed to view. But with the domesticated descendant of this species, the

neckhackles of the male are immediately replaced by new ones; so that we here see, as to part of the

plumage, a double moult changed under domestication into a single moult. (82. For the foregoing statements

in regard to partial moults, and on old males retaining their nuptial plumage, see Jerdon, on bustards and

plovers, in 'Birds of India,' vol. iii. pp. 617, 637, 709, 711. Also Blyth in 'Land and Water,' 1867, p. 84. On

the moulting of Paradisea, see an interesting article by Dr. W. Marshall, 'Archives Neerlandaises,' tom. vi.

1871. On the Vidua, 'Ibis,' vol. iii. 1861, p. 133. On the Drongo shrikes, Jerdon, ibid. vol. i. p. 435. On the

vernal moult of the Herodias bubulcus, Mr. S.S. Allen, in 'Ibis,' 1863, p. 33. On Gallus bankiva, Blyth, in

'Annals and Mag. of Natural History,' vol. i. 1848, p. 455; see, also, on this subject, my 'Variation of Animals

The common drake (Anas boschas), after the breedingseason, is well known to lose his male plumage for a

period of three months, during which time he assumes that of the female. The male pintail duck (Anas

acuta) loses his plumage for the shorter period of six weeks or two months; and Montagu remarks that "this

double moult within so short a time is a most extraordinary circumstance, that seems to bid defiance to all

human reasoning." But the believer in the gradual modification of species will be far from feeling surprise at

finding gradations of all kinds. If the male pintail were to acquire his new plumage within a still shorter

period, the new male feathers would almost necessarily be mingled with the old, and both with some proper

to the female; and this apparently is the case with the male of a not distantlyallied bird, namely the

Merganser serrator, for the males are said to "undergo a change of plumage, which assimilates them in some

measure to the female." By a little further acceleration in the process, the double moult would be completely

lost. (83. See Macgillivray, 'Hist. British Birds' (vol. v. pp. 34, 70, and 223), on the moulting of the Anatidae,

with quotations from Waterton and Montagu. Also Yarrell, 'History of British Birds,' vol. iii. p. 243.)

Some male birds, as before stated, become more brightly coloured in the spring, not by a vernal moult, but

either by an actual change of colour in the feathers, or by their obscurelycoloured deciduary margins being

shed. Changes of colour thus caused may last for a longer or shorter time. In the Pelecanus onocrotalus a

beautiful rosy tint, with lemoncoloured marks on the breast, overspreads the whole plumage in the spring;

but these tints, as Mr. Sclater states, "do not last long, disappearing generally in about six weeks or two

months after they have been attained." Certain finches shed the margins of their feathers in the spring, and

then become brighter coloured, while other finches undergo no such change. Thus the Fringilla tristis of the

United States (as well as many other American species) exhibits its bright colours only when the winter is

past, whilst our goldfinch, which exactly represents this bird in habits, and our siskin, which represents it still

more closely in structure, undergo no such annual change. But a difference of this kind in the plumage of

allied species is not surprising, for with the common linnet, which belongs to the same family, the crimson

forehead and breast are displayed only during the summer in England, whilst in Madeira these colours are

retained throughout the year. (84. On the pelican, see Sclater, in 'Proc. Zool. Soc.' 1868, p. 265. On the

American finches, see Audubon, 'Ornithological Biography,' vol. i. pp. 174, 221, and Jerdon, 'Birds of India,'

vol. ii. p. 383. On the Fringilla cannabina of Madeira, Mr. E. Vernon Harcourt, 'Ibis,' vol. v. 1863, p. 230.)

Ornaments of all kinds, whether permanently or temporarily gained, are sedulously displayed by the males,

and apparently serve to excite, attract, or fascinate the females. But the males will sometimes display their

ornaments, when not in the presence of the females, as occasionally occurs with grouse at their balzplaces,

and as may be noticed with the peacock; this latter bird, however, evidently wishes for a spectator of some

kind, and, as I have often seen, will shew off his finery before poultry, or even pigs. (85. See also

'Ornamental Poultry,' by Rev. E.S. Dixon, 1848, p. 8.) All naturalists who have closely attended to the habits

of birds, whether in a state of nature or under confinement, are unanimously of opinion that the males take

delight in displaying their beauty. Audubon frequently speaks of the male as endeavouring in various ways to

charm the female. Mr. Gould, after describing some peculiarities in a male humming bird, says he has no

doubt that it has the power of displaying them to the greatest advantage before the female. Dr. Jerdon (86.

'Birds of India,' introduct., vol. i. p. xxiv.; on the peacock, vol. iii. p. 507. See Gould's 'Introduction to

Trochilidae,' 1861, pp. 15 and 111.) insists that the beautiful plumage of the male serves "to fascinate and

attract the female." Mr. Bartlett, at the Zoological Gardens, expressed himself to me in the strongest terms to

It must be a grand sight in the forests of India "to come suddenly on twenty or thirty peafowl, the males

displaying their gorgeous trains, and strutting about in all the pomp of pride before the gratified females."

The wild turkeycock erects his glittering plumage, expands his finely zoned tail and barred wingfeathers,

and altogether, with his crimson and blue wattles, makes a superb, though, to our eyes, grotesque appearance.

Similar facts have already been given with respect to grouse of various kinds. Turning to another Order: The

male Rupicola crocea (Fig. 50) is one of the most beautiful birds in the world, being of a splendid orange,

with some of the feathers curiously truncated and plumose. The female is brownishgreen, shaded with red,

and has a much smaller crest. Sir R. Schomburgk has described their courtship; he found one of their

meeting places where ten males and two females were present. The space was from four to five feet in

diameter, and appeared to have been cleared of every blade of grass and smoothed as if by human hands. A

male "was capering, to the apparent delight of several others. Now spreading its wings, throwing up its head,

or opening its tail like a fan; now strutting about with a hopping gait until tired, when it gabbled some kind of

note, and was relieved by another. Thus three of them successively took the field, and then, with

selfapprobation, withdrew to rest." The Indians, in order to obtain their skins, wait at one of the

meetingplaces till the birds are eagerly engaged in dancing, and then are able to kill with their poisoned

arrows four or five males, one after the other. (87. 'Journal of R. Geograph. Soc.' vol. x. 1840, p. 236.) With

birds of paradise a dozen or more fullplumaged males congregate in a tree to hold a dancingparty, as it is

called by the natives: and here they fly about, raise their wings, elevate their exquisite plumes, and make

them vibrate, and the whole tree seems, as Mr. Wallace remarks, to be filled with waving plumes. When thus

engaged, they become so absorbed that a skilful archer may shoot nearly the whole party. These birds, when

kept in confinement in the Malay Archipelago, are said to take much care in keeping their feathers clean;

often spreading them out, examining them, and removing every speck of dirt. One observer, who kept several

pairs alive, did not doubt that the display of the male was intended to please the female. (88. 'Annals and

Mag. of Nat. Hist.' vol. xiii. 1854, p. 157; also Wallace, ibid. vol. xx. 1857, p. 412, and 'The Malay

Archipelago,' vol. ii. 1869, p. 252. Also Dr. Bennett, as quoted by Brehm, 'Thierleben,' B. iii. s. 326.)

The Gold and Amherst pheasants during their courtship not only expand and raise their splendid frills, but

twist them, as I have myself seen, obliquely towards the female on whichever side she may be standing,

obviously in order that a large surface may be displayed before her. (89. Mr. T.W. Wood has given ('The

Student,' April 1870, p. 115) a full account of this manner of display, by the Gold pheasant and by the

Japanese pheasant, Ph. versicolor; and he calls it the lateral or onesided display.) They likewise turn their

beautiful tails and tailcoverts a little towards the same side. Mr. Bartlett has observed a male Polyplectron

(Fig. 51) in the act of courtship, and has shewn me a specimen stuffed in the attitude then assumed. The tail

and wingfeathers of this bird are ornamented with beautiful ocelli, like those on the peacock's train. Now

when the peacock displays himself, he expands and erects his tail transversely to his body, for he stands in

front of the female, and has to shew off, at the same time, his rich blue throat and breast. But the breast of the

Polyplectron is obscurely coloured, and the ocelli are not confined to the tailfeathers. Consequently the

Polyplectron does not stand in front of the female; but he erects and expands his tailfeathers a little

obliquely, lowering the expanded wing on the same side, and raising that on the opposite side. In this attitude

the ocelli over the whole body are exposed at the same time before the eyes of the admiring female in one

grand bespangled expanse. To whichever side she may turn, the expanded wings and the obliquelyheld tail

are turned towards her. The male Tragopan pheasant acts in nearly the same manner, for he raises the feathers

of the body, though not the wing itself, on the side which is opposite to the female, and which would

otherwise be concealed, so that nearly all the beautifully spotted feathers are exhibited at the same time.

[Fig. 52. Side view of male Argus pheasant, whilst displaying before the female. Observed and sketched from

The Argus pheasant affords a much more remarkable case. The immensely developed secondary

wingfeathers are confined to the male; and each is ornamented with a row of from twenty to twentythree

ocelli, above an inch in diameter. These feathers are also elegantly marked with oblique stripes and rows of

spots of a dark colour, like those on the skin of a tiger and leopard combined. These beautiful ornaments are

hidden until the male shows himself off before the female. He then erects his tail, and expands his

wingfeathers into a great, almost upright, circular fan or shield, which is carried in front of the body. The

neck and head are held on one side, so that they are concealed by the fan; but the bird in order to see the

female, before whom he is displaying himself, sometimes pushes his head between two of the long

wingfeathers (as Mr. Bartlett has seen), and then presents a grotesque appearance. This must be a frequent

habit with the bird in a state of nature, for Mr. Bartlett and his son on examining some perfect skins sent from

the East, found a place between two of the feathers which was much frayed, as if the head had here frequently

been pushed through. Mr. Wood thinks that the male can also peep at the female on one side, beyond the

The ocelli on the wingfeathers are wonderful objects; for they are so shaded that, as the Duke of Argyll

remarks (90. 'The Reign of Law,' 1867, p. 203.), they stand out like balls lying loosely within sockets. When I

looked at the specimen in the British Museum, which is mounted with the wings expanded and trailing

downwards, I was however greatly disappointed, for the ocelli appeared flat, or even concave. But Mr. Gould

soon made the case clear to me, for he held the feathers erect, in the position in which they would naturally be

displayed, and now, from the light shining on them from above, each ocellus at once resembled the ornament

called a ball and socket. These feathers have been shown to several artists, and all have expressed their

admiration at the perfect shading. It may well be asked, could such artistically shaded ornaments have been

formed by means of sexual selection? But it will be convenient to defer giving an answer to this question

The foregoing remarks relate to the secondary wingfeathers, but the primary wingfeathers, which in most

gallinaceous birds are uniformly coloured, are in the Argus pheasant equally wonderful. They are of a soft

brown tint with numerous dark spots, each of which consists of two or three black dots with a surrounding

dark zone. But the chief ornament is a space parallel to the darkblue shaft, which in outline forms a perfect

second feather lying within the true feather. This inner part is coloured of a lighter chestnut, and is thickly

dotted with minute white points. I have shewn this feather to several persons, and many have admired it even

more than the ball and socket feathers, and have declared that it was more like a work of art than of nature.

Now these feathers are quite hidden on all ordinary occasions, but are fully displayed, together with the long

secondary feathers, when they are all expanded together so as to form the great fan or shield.

The case of the male Argus pheasant is eminently interesting, because it affords good evidence that the most

refined beauty may serve as a sexual charm, and for no other purpose. We must conclude that this is the case,

as the secondary and primary wingfeathers are not at all displayed, and the ball and socket ornaments are

not exhibited in full perfection until the male assumes the attitude of courtship. The Argus pheasant does not

possess brilliant colours, so that his success in love appears to depend on the great size of his plumes, and on

the elaboration of the most elegant patterns. Many will declare that it is utterly incredible that a female bird

should be able to appreciate fine shading and exquisite patterns. It is undoubtedly a marvellous fact that she

should possess this almost human degree of taste. He who thinks that he can safely gauge the discrimination

and taste of the lower animals may deny that the female Argus pheasant can appreciate such refined beauty;

but he will then be compelled to admit that the extraordinary attitudes assumed by the male during the act of

courtship, by which the wonderful beauty of his plumage is fully displayed, are purposeless; and this is a

Although so many pheasants and allied gallinaceous birds carefully display their plumage before the females,

it is remarkable, as Mr. Bartlett informs me, that this is not the case with the dullcoloured Eared and Cheer

pheasants (Crossoptilon auritum and Phasianus wallichii); so that these birds seem conscious that they have

little beauty to display. Mr. Bartlett has never seen the males of either of these species fighting together,

though he has not had such good opportunities for observing the Cheer as the Eared pheasant. Mr. Jenner

Weir, also, finds that all male birds with rich or stronglycharacterised plumage are more quarrelsome than

the dull coloured species belonging to the same groups. The goldfinch, for instance, is far more pugnacious

than the linnet, and the blackbird than the thrush. Those birds which undergo a seasonal change of plumage

likewise become much more pugnacious at the period when they are most gaily ornamented. No doubt the

males of some obscurelycoloured birds fight desperately together, but it appears that when sexual selection

has been highly influential, and has given bright colours to the males of any species, it has also very often

given a strong tendency to pugnacity. We shall meet with nearly analogous cases when we treat of mammals.

On the other hand, with birds the power of song and brilliant colours have rarely been both acquired by the

males of the same species; but in this case the advantage gained would have been the same, namely success

in charming the female. Nevertheless it must be owned that the males of several brilliantly coloured birds

have had their feathers specially modified for the sake of producing instrumental music, though the beauty of

this cannot be compared, at least according to our taste, with that of the vocal music of many songsters.

We will now turn to male birds which are not ornamented in any high degree, but which nevertheless display

during their courtship whatever attractions they may possess. These cases are in some respects more curious

than the foregoing, and have been but little noticed. I owe the following facts to Mr. Weir, who has long kept

confined birds of many kinds, including all the British Fringillidae and Emberizidae. The facts have been

selected from a large body of valuable notes kindly sent me by him. The bullfinch makes his advances in

front of the female, and then puffs out his breast, so that many more of the crimson feathers are seen at once

than otherwise would be the case. At the same time he twists and bows his black tail from side to side in a

ludicrous manner. The male chaffinch also stands in front of the female, thus shewing his red breast and "blue

bell," as the fanciers call his head; the wings at the same time being slightly expanded, with the pure white

bands on the shoulders thus rendered conspicuous. The common linnet distends his rosy breast, slightly

expands his brown wings and tail, so as to make the best of them by exhibiting their white edgings. We must,

however, be cautious in concluding that the wings are spread out solely for display, as some birds do so

whose wings are not beautiful. This is the case with the domestic cock, but it is always the wing on the side

opposite to the female which is expanded, and at the same time scraped on the ground. The male goldfinch

behaves differently from all other finches: his wings are beautiful, the shoulders being black, with the

darktipped wingfeathers spotted with white and edged with golden yellow. When he courts the female, he

sways his body from side to side, and quickly turns his slightly expanded wings first to one side, then to the

other, with a golden flashing effect. Mr. Weir informs me that no other British finch turns thus from side to

side during his courtship, not even the closely allied male siskin, for he would not thus add to his beauty.

Most of the British Buntings are plain coloured birds; but in the spring the feathers on the head of the male

reedbunting (Emberiza schoeniculus) acquire a fine black colour by the abrasion of the dusky tips; and these

are erected during the act of courtship. Mr. Weir has kept two species of Amadina from Australia: the A.

castanotis is a very small and chastely coloured finch, with a dark tail, white rump, and jetblack upper tail

coverts, each of the latter being marked with three large conspicuous oval spots of white. (91. For the

description of these birds, see Gould's 'Handbook to the Birds of Australia,' vol. i. 1865, p. 417.) This species,

when courting the female, slightly spreads out and vibrates these parti coloured tailcoverts in a very

peculiar manner. The male Amadina Lathami behaves very differently, exhibiting before the female his

brilliantly spotted breast, scarlet rump, and scarlet upper tailcoverts. I may here add from Dr. Jerdon that the

Indian bulbul (Pycnonotus hoemorrhous) has its under tailcoverts of a crimson colour, and these, it might be

thought, could never be well exhibited; but the bird "when excited often spreads them out laterally, so that

they can be seen even from above." (92. 'Birds of India,' vol. ii. p. 96.) The crimson under tailcoverts of

some other birds, as with one of the woodpeckers, Picus major, can be seen without any such display. The

common pigeon has iridescent feathers on the breast, and every one must have seen how the male inflates his

breast whilst courting the female, thus shewing them off to the best advantage. One of the beautiful

bronzewinged pigeons of Australia (Ocyphaps lophotes) behaves, as described to me by Mr. Weir, very

differently: the male, whilst standing before the female, lowers his head almost to the ground, spreads out and

raises his tail, and half expands his wings. He then alternately and slowly raises and depresses his body, so

that the iridescent metallic feathers are all seen at once, and glitter in the sun.

Sufficient facts have now been given to shew with what care male birds display their various charms, and this

they do with the utmost skill. Whilst preening their feathers, they have frequent opportunities for admiring

themselves, and of studying how best to exhibit their beauty. But as all the males of the same species display

themselves in exactly the same manner, it appears that actions, at first perhaps intentional, have become

instinctive. If so, we ought not to accuse birds of conscious vanity; yet when we see a peacock strutting

about, with expanded and quivering tail feathers, he seems the very emblem of pride and vanity.

The various ornaments possessed by the males are certainly of the highest importance to them, for in some

cases they have been acquired at the expense of greatly impeded powers of flight or of running. The African

nightjar (Cosmetornis), which during the pairingseason has one of its primary wingfeathers developed

into a streamer of very great length, is thereby much retarded in its flight, although at other times remarkable

for its swiftness. The "unwieldy size" of the secondary wingfeathers of the male Argus pheasant is said

"almost entirely to deprive the bird of flight." The fine plumes of male birds of paradise trouble them during a

high wind. The extremely long tailfeathers of the male widowbirds (Vidua) of Southern Africa render

"their flight heavy;" but as soon as these are cast off they fly as well as the females. As birds always breed

when food is abundant, the males probably do not suffer much inconvenience in searching for food from their

impeded powers of movement; but there can hardly be a doubt that they must be much more liable to be

struck down by birds of prey. Nor can we doubt that the long train of the peacock and the long tail and

wingfeathers of the Argus pheasant must render them an easier prey to any prowling tigercat than would

otherwise be the case. Even the bright colours of many male birds cannot fail to make them conspicuous to

their enemies of all kinds. Hence, as Mr. Gould has remarked, it probably is that such birds are generally of a

shy disposition, as if conscious that their beauty was a source of danger, and are much more difficult to

discover or approach, than the sombre coloured and comparatively tame females or than the young and as yet

unadorned males. (93. On the Cosmetornis, see Livingstone's 'Expedition to the Zambesi,' 1865, p. 66. On the

Argus pheasant, Jardine's 'Nat. Hist. Lib.: Birds,' vol. xiv. p. 167. On Birds of Paradise, Lesson, quoted by

Brehm, 'Thierleben,' B. iii. s. 325. On the widowbird, Barrow's 'Travels in Africa,' vol. i. p. 243, and 'Ibis,'

vol. iii. 1861 p. 133. Mr. Gould, on the shyness of male birds, 'Handbook to Birds of Australia,' vol. i. 1865,

It is a more curious fact that the males of some birds which are provided with special weapons for battle, and

which in a state of nature are so pugnacious that they often kill each other, suffer from possessing certain

ornaments. Cockfighters trim the hackles and cut off the combs and gills of their cocks; and the birds are

then said to be dubbed. An undubbed bird, as Mr. Tegetmeier insists, "is at a fearful disadvantage; the comb

and gills offer an easy hold to his adversary's beak, and as a cock always strikes where he holds, when once

he has seized his foe, he has him entirely in his power. Even supposing that the bird is not killed, the loss of

blood suffered by an undubbed cock is much greater than that sustained by one that has been trimmed." (94.

Tegetmeier, 'The Poultry Book,' 1866, p. 139.) Young turkeycocks in fighting always seize hold of each

other's wattles; and I presume that the old birds fight in the same manner. It may perhaps be objected that the

comb and wattles are not ornamental, and cannot be of service to the birds in this way; but even to our eyes,

the beauty of the glossy black Spanish cock is much enhanced by his white face and crimson comb; and no

one who has ever seen the splendid blue wattles of the male Tragopan pheasant distended in courtship can for

a moment doubt that beauty is the object gained. From the foregoing facts we clearly see that the plumes and

other ornaments of the males must be of the highest importance to them; and we further see that beauty is

Choice exerted by the femaleLength of courtshipUnpaired birdsMental qualities and taste for the

beautifulPreference or antipathy shewn by the female for particular malesVariability of

birdsVariations sometimes abruptLaws of variationFormation of ocelliGradations of character

When the sexes differ in beauty or in the power of singing, or in producing what I have called instrumental

music, it is almost invariably the male who surpasses the female. These qualities, as we have just seen, are

evidently of high importance to the male. When they are gained for only a part of the year it is always before

the breedingseason. It is the male alone who elaborately displays his varied attractions, and often performs

strange antics on the ground or in the air, in the presence of the female. Each male drives away, or if he can,

kills his rivals. Hence we may conclude that it is the object of the male to induce the female to pair with him,

and for this purpose he tries to excite or charm her in various ways; and this is the opinion of all those who

have carefully studied the habits of living birds. But there remains a question which has an all important

bearing on sexual selection, namely, does every male of the same species excite and attract the female

equally? Or does she exert a choice, and prefer certain males? This latter question can be answered in the

affirmative by much direct and indirect evidence. It is far more difficult to decide what qualities determine

the choice of the females; but here again we have some direct and indirect evidence that it is to a large extent

the external attractions of the male; though no doubt his vigour, courage, and other mental qualities come into

The lengthened period during which both sexes of certain birds meet day after day at an appointed place

probably depends partly on the courtship being a prolonged affair, and partly on reiteration in the act of

pairing. Thus in Germany and Scandinavia the balzen or leks of the blackcocks last from the middle of

March, all through April into May. As many as forty or fifty, or even more birds congregate at the leks; and

the same place is often frequented during successive years. The lek of the capercailzie lasts from the end of

March to the middle or even end of May. In North America "the partridge dances" of the Tetrao phasianellus

"last for a month or more." Other kinds of grouse, both in North America and Eastern Siberia (1. Nordman

describes ('Bull. Soc. Imp. des Nat. Moscou,' 1861, tom. xxxiv. p. 264) the balzen of Tetrao urogalloides in

Amur Land. He estimated the number of birds assembled at above a hundred, not counting the females,

which lie hid in the surrounding bushes. The noises uttered differ from those of T. urogallus.), follow nearly

the same habits. The fowlers discover the hillocks where the ruffs congregate by the grass being trampled

bare, and this shews that the same spot is long frequented. The Indians of Guiana are well acquainted with the

cleared arenas, where they expect to find the beautiful cocks of the Rock; and the natives of New Guinea

know the trees where from ten to twenty male birds of paradise in full plumage congregate. In this latter case

it is not expressly stated that the females meet on the same trees, but the hunters, if not specially asked, would

probably not mention their presence, as their skins are valueless. Small parties of an African weaver

(Ploceus) congregate, during the breedingseason, and perform for hours their graceful evolutions. Large

numbers of the Solitary snipe (Scolopax major) assemble during dusk in a morass; and the same place is

frequented for the same purpose during successive years; here they may be seen running about "like so many

large rats," puffing out their feathers, flapping their wings, and uttering the strangest cries. (2. With respect to

the assemblages of the above named grouse, see Brehm, 'Thierleben,' B. iv. s. 350; also L. Lloyd, 'Game

Birds of Sweden,' 1867, pp. 19, 78. Richardson, 'Fauna Bor. Americana: Birds,' p. 362. References in regard

to the assemblages of other birds have already been given. On Paradisea, see Wallace, in 'Annals and Mag. of

Some of the above birds,the blackcock, capercailzie, pheasantgrouse, ruff, solitary snipe, and perhaps

others,are, as is believed, polygamists. With such birds it might have been thought that the stronger males

would simply have driven away the weaker, and then at once have taken possession of as many females as

possible; but if it be indispensable for the male to excite or please the female, we can understand the length of

the courtship and the congregation of so many individuals of both sexes at the same spot. Certain strictly

monogamous species likewise hold nuptial assemblages; this seems to be the case in Scandinavia with one of

the ptarmigans, and their leks last from the middle of March to the middle of May. In Australia the lyrebird

(Menura superba) forms "small round hillocks," and the M. Alberti scratches for itself shallow holes, or, as

they are called by the natives, "corroborying places," where it is believed both sexes assemble. The meetings

of the M. superba are sometimes very large; and an account has lately been published (3. Quoted by Mr. T.W.

Wood, in the 'Student,' April 1870, p. 125.) by a traveller, who heard in a valley beneath him, thickly covered

with scrub, "a din which completely astonished" him; on crawling onwards he beheld, to his amazement,

about one hundred and fifty of the magnificent lyrecocks, "ranged in order of battle, and fighting with

indescribable fury." The bowers of the Bower birds are the resort of both sexes during the breedingseason;

and "here the males meet and contend with each other for the favours of the female, and here the latter

assemble and coquet with the males." With two of the genera, the same bower is resorted to during many

years. (4. Gould, 'Handbook to the Birds of Australia,' vol. i. pp. 300, 308, 448, 451. On the ptarmigan, above

The common magpie (Corvus pica, Linn.), as I have been informed by the Rev. W. Darwin Fox, used to

assemble from all parts of Delamere Forest, in order to celebrate the "great magpie marriage." Some years

ago these birds abounded in extraordinary numbers, so that a gamekeeper killed in one morning nineteen

males, and another killed by a single shot seven birds at roost together. They then had the habit of assembling

very early in the spring at particular spots, where they could be seen in flocks, chattering, sometimes fighting,

bustling and flying about the trees. The whole affair was evidently considered by the birds as one of the

highest importance. Shortly after the meeting they all separated, and were then observed by Mr. Fox and

others to be paired for the season. In any district in which a species does not exist in large numbers, great

assemblages cannot, of course, be held, and the same species may have different habits in different countries.

For instance, I have heard of only one instance, from Mr. Wedderburn, of a regular assemblage of black game

in Scotland, yet these assemblages are so well known in Germany and Scandinavia that they have received

From the facts now given, we may conclude that the courtship of birds belonging to widely different groups,

is often a prolonged, delicate, and troublesome affair. There is even reason to suspect, improbable as this will

at first appear, that some males and females of the same species, inhabiting the same district, do not always

please each other, and consequently do not pair. Many accounts have been published of either the male or

female of a pair having been shot, and quickly replaced by another. This has been observed more frequently

with the magpie than with any other bird, owing perhaps to its conspicuous appearance and nest. The

illustrious Jenner states that in Wiltshire one of a pair was daily shot no less than seven times successively,

"but all to no purpose, for the remaining magpie soon found another mate"; and the last pair reared their

young. A new partner is generally found on the succeeding day; but Mr. Thompson gives the case of one

being replaced on the evening of the same day. Even after the eggs are hatched, if one of the old birds is

destroyed a mate will often be found; this occurred after an interval of two days, in a case recently observed

by one of Sir J. Lubbock's keepers. (5. On magpies, Jenner, in 'Philosophical Transactions,' 1824, p. 21.

Macgillivray, 'Hist. British Birds,' vol. i. p. 570. Thompson, in 'Annals and Magazine of Natural History,' vol.

viii. 1842, p. 494.) The first and most obvious conjecture is that male magpies must be much more numerous

than females; and that in the above cases, as well as in many others which could be given, the males alone

had been killed. This apparently holds good in some instances, for the gamekeepers in Delamere Forest

assured Mr. Fox that the magpies and carrioncrows which they formerly killed in succession in large

numbers near their nests, were all males; and they accounted for this fact by the males being easily killed

whilst bringing food to the sitting females. Macgillivray, however, gives, on the authority of an excellent

observer, an instance of three magpies successively killed on the same nest, which were all females; and

another case of six magpies successively killed whilst sitting on the same eggs, which renders it probable that

most of them were females; though, as I hear from Mr. Fox, the male will sit on the eggs when the female is

Sir J. Lubbock's gamekeeper has repeatedly shot, but how often he could not say, one of a pair of jays

(Garrulus glandarius), and has never failed shortly afterwards to find the survivor rematched. Mr. Fox, Mr.

F. Bond, and others have shot one of a pair of carrioncrows (Corvus corone), but the nest was soon again

tenanted by a pair. These birds are rather common; but the peregrinefalcon (Falco peregrinus) is rare, yet

Mr. Thompson states that in Ireland "if either an old male or female be killed in the breedingseason (not an

uncommon circumstance), another mate is found within a very few days, so that the eyries, notwithstanding

such casualties, are sure to turn out their complement of young." Mr. Jenner Weir has known the same thing

with the peregrinefalcons at Beachy Head. The same observer informs me that three kestrels (Falco

tinnunculus), all males, were killed one after the other whilst attending the same nest; two of these were in

mature plumage, but the third was in the plumage of the previous year. Even with the rare golden eagle

(Aquila chrysaetos), Mr. Birkbeck was assured by a trustworthy gamekeeper in Scotland, that if one is killed,

another is soon found. So with the white owl (Strix flammea), "the survivor readily found a mate, and the

White of Selborne, who gives the case of the owl, adds that he knew a man, who from believing that

partridges when paired were disturbed by the males fighting, used to shoot them; and though he had widowed

the same female several times, she always soon found a fresh partner. This same naturalist ordered the

sparrows, which deprived the housemartins of their nests, to be shot; but the one which was left, "be it cock

or hen, presently procured a mate, and so for several times following." I could add analogous cases relating to

the chaffinch, nightingale, and redstart. With respect to the latter bird (Phoenicura ruticilla), a writer

expresses much surprise how the sitting female could so soon have given effectual notice that she was a

widow, for the species was not common in the neighbourhood. Mr. Jenner Weir has mentioned to me a nearly

similar case; at Blackheath he never sees or hears the note of the wild bullfinch, yet when one of his caged

males has died, a wild one in the course of a few days has generally come and perched near the widowed

female, whose callnote is not loud. I will give only one other fact, on the authority of this same observer;

one of a pair of starlings (Sturnus vulgaris) was shot in the morning; by noon a new mate was found; this was

again shot, but before night the pair was complete; so that the disconsolate widow or widower was thrice

consoled during the same day. Mr. Engleheart also informs me that he used during several years to shoot one

of a pair of starlings which built in a hole in a house at Blackheath; but the loss was always immediately

repaired. During one season he kept an account, and found that he had shot thirtyfive birds from the same

nest; these consisted of both males and females, but in what proportion he could not say: nevertheless, after

all this destruction, a brood was reared. (6. On the peregrine falcon, see Thompson, 'Nat. Hist. of Ireland:

Birds,' vol. i. 1849, p. 39. On owls, sparrows, and partridges, see White, 'Nat. Hist. of Selborne,' edit. of 1825,

vol. i. p. 139. On the Phoenicura, see Loudon's 'Mag. of Nat. Hist.' vol. vii. 1834, p. 245. Brehm ('Thierleben,'

B. iv. s. 991) also alludes to cases of birds thrice mated during the same day.)

These facts well deserve attention. How is it that there are birds enough ready to replace immediately a lost

mate of either sex? Magpies, jays, carrioncrows, partridges, and some other birds, are always seen during

the spring in pairs, and never by themselves; and these offer at first sight the most perplexing cases. But birds

of the same sex, although of course not truly paired, sometimes live in pairs or in small parties, as is known to

be the case with pigeons and partridges. Birds also sometimes live in triplets, as has been observed with

starlings, carrioncrows, parrots, and partridges. With partridges two females have been known to live with

one male, and two males with one female. In all such cases it is probable that the union would be easily

broken; and one of the three would readily pair with a widow or widower. The males of certain birds may

occasionally be heard pouring forth their lovesong long after the proper time, shewing that they have either

lost or never gained a mate. Death from accident or disease of one of a pair would leave the other free and

single; and there is reason to believe that female birds during the breedingseason are especially liable to

premature death. Again, birds which have had their nests destroyed, or barren pairs, or retarded individuals,

would easily be induced to desert their mates, and would probably be glad to take what share they could of

the pleasures and duties of rearing offspring although not their own. (7. See White ('Nat. Hist. of Selborne,'

1825, vol. i. p. 140) on the existence, early in the season, of small coveys of male partridges, of which fact I

have heard other instances. See Jenner, on the retarded state of the generative organs in certain birds, in 'Phil.

Transact.' 1824. In regard to birds living in triplets, I owe to Mr. Jenner Weir the cases of the starlings and

parrots, and to Mr. Fox, of partridges; on carrioncrows, see the 'Field,' 1868, p. 415. On various male birds

singing after the proper period, see Rev. L. Jenyns, 'Observations in Natural History,' 1846, p. 87.) Such

contingencies as these probably explain most of the foregoing cases. (8. The following case has been given

('The Times,' Aug. 6, 1868) by the Rev. F.O. Morris, on the authority of the Hon. and Rev. O.W. Forester.

"The gamekeeper here found a hawk's nest this year, with five young ones on it. He took four and killed

them, but left one with its wings clipped as a decoy to destroy the old ones by. They were both shot next day,

in the act of feeding the young one, and the keeper thought it was done with. The next day he came again and

found two other charitable hawks, who had come with an adopted feeling to succour the orphan. These two

he killed, and then left the nest. On returning afterwards he found two more charitable individuals on the

same errand of mercy. One of these he killed; the other he also shot, but could not find. No more came on the

like fruitless errand.") Nevertheless, it is a strange fact that within the same district, during the height of the

breedingseason, there should be so many males and females always ready to repair the loss of a mated bird.

Why do not such spare birds immediately pair together? Have we not some reason to suspect, and the

suspicion has occurred to Mr. Jenner Weir, that as the courtship of birds appears to be in many cases

prolonged and tedious, so it occasionally happens that certain males and females do not succeed, during the

proper season, in exciting each other's love, and consequently do not pair? This suspicion will appear

somewhat less improbable after we have seen what strong antipathies and preferences female birds

Before we further discuss the question whether the females select the more attractive males or accept the first

whom they may encounter, it will be advisable briefly to consider the mental powers of birds. Their reason is

generally, and perhaps justly, ranked as low; yet some facts could be given leading to an opposite conclusion.

(9. I am indebted to Prof. Newton for the following passage from Mr. Adam's 'Travels of a Naturalist,' 1870,

p. 278. Speaking of Japanese nuthatches in confinement, he says: "Instead of the more yielding fruit of the

yew, which is the usual food of the nut hatch of Japan, at one time I substituted hard hazelnuts. As the bird

was unable to crack them, he placed them one by one in his waterglass, evidently with the notion that they

would in time become softeran interesting proof of intelligence on the part of these birds.") Low powers of

reasoning, however, are compatible, as we see with mankind, with strong affections, acute perception, and a

taste for the beautiful; and it is with these latter qualities that we are here concerned. It has often been said

that parrots become so deeply attached to each other that when one dies the other pines for a long time; but

Mr. Jenner Weir thinks that with most birds the strength of their affection has been much exaggerated.

Nevertheless when one of a pair in a state of nature has been shot, the survivor has been heard for days

afterwards uttering a plaintive call; and Mr. St. John gives various facts proving the attachment of mated

birds. (10. 'A Tour in Sutherlandshire,' vol. i. 1849, p. 185. Dr. Buller says ('Birds of New Zealand,' 1872, p.

56) that a male King Lory was killed; and the female "fretted and moped, refused her food, and died of a

broken heart.") Mr. Bennett relates (11. 'Wanderings in New South Wales,' vol. ii. 1834, p. 62.) that in China

after a drake of the beautiful mandarin Teal had been stolen, the duck remained disconsolate, though

sedulously courted by another mandarin drake, who displayed before her all his charms. After an interval of

three weeks the stolen drake was recovered, and instantly the pair recognised each other with extreme joy. On

the other hand, starlings, as we have seen, may be consoled thrice in the same day for the loss of their mates.

Pigeons have such excellent local memories, that they have been known to return to their former homes after

an interval of nine months, yet, as I hear from Mr. Harrison Weir, if a pair which naturally would remain

mated for life be separated for a few weeks during the winter, and afterwards matched with other birds, the

Birds sometimes exhibit benevolent feelings; they will feed the deserted young ones even of distinct species,

but this perhaps ought to be considered as a mistaken instinct. They will feed, as shewn in an earlier part of

this work, adult birds of their own species which have become blind. Mr. Buxton gives a curious account of a

parrot which took care of a frostbitten and crippled bird of a distinct species, cleansed her feathers, and

defended her from the attacks of the other parrots which roamed freely about his garden. It is a still more

curious fact that these birds apparently evince some sympathy for the pleasures of their fellows. When a pair

of cockatoos made a nest in an acacia tree, "it was ridiculous to see the extravagant interest taken in the

matter by the others of the same species." These parrots, also, evinced unbounded curiosity, and clearly had

"the idea of property and possession." (12. 'Acclimatization of Parrots,' by C. Buxton, M.P., 'Annals and Mag.

of Nat. Hist.' Nov. 1868, p. 381.) They have good memories, for in the Zoological Gardens they have plainly

Birds possess acute powers of observation. Every mated bird, of course, recognises its fellow. Audubon states

that a certain number of mocking thrushes (Mimus polyglottus) remain all the year round in Louisiana,

whilst others migrate to the Eastern States; these latter, on their return, are instantly recognised, and always

attacked, by their southern brethren. Birds under confinement distinguish different persons, as is proved by

the strong and permanent antipathy or affection which they shew, without any apparent cause, towards certain

individuals. I have heard of numerous instances with jays, partridges, canaries, and especially bullfinches.

Mr. Hussey has described in how extraordinary a manner a tamed partridge recognised everybody: and its

likes and dislikes were very strong. This bird seemed "fond of gay colours, and no new gown or cap could be

put on without catching his attention." (13. The 'Zoologist,' 184748, p. 1602.) Mr. Hewitt has described the

habits of some ducks (recently descended from wild birds), which, at the approach of a strange dog or cat,

would rush headlong into the water, and exhaust themselves in their attempts to escape; but they knew Mr.

Hewitt's own dogs and cats so well that they would lie down and bask in the sun close to them. They always

moved away from a strange man, and so they would from the lady who attended them if she made any great

change in her dress. Audubon relates that he reared and tamed a wild turkey which always ran away from any

strange dog; this bird escaped into the woods, and some days afterwards Audubon saw, as he thought, a wild

turkey, and made his dog chase it; but, to his astonishment, the bird did not run away, and the dog, when he

came up, did not attack the bird, for they mutually recognised each other as old friends. (14. Hewitt on wild

ducks, 'Journal of Horticulture,' Jan. 13, 1863, p. 39. Audubon on the wild turkey, 'Ornithological Biography,'

Mr. Jenner Weir is convinced that birds pay particular attention to the colours of other birds, sometimes out

of jealousy, and sometimes as a sign of kinship. Thus he turned a reedbunting (Emberiza schoeniculus),

which had acquired its black headdress, into his aviary, and the newcomer was not noticed by any bird,

except by a bullfinch, which is likewise black headed. This bullfinch was a very quiet bird, and had never

before quarrelled with any of its comrades, including another reedbunting, which had not as yet become

blackheaded: but the reedbunting with a black head was so unmercifully treated that it had to be removed.

Spiza cyanea, during the breedingseason, is of a bright blue colour; and though generally peaceable, it

attacked S. ciris, which has only the head blue, and completely scalped the unfortunate bird. Mr. Weir was

also obliged to turn out a robin, as it fiercely attacked all the birds in his aviary with any red in their plumage,

but no other kinds; it actually killed a red breasted crossbill, and nearly killed a goldfinch. On the other

band, he has observed that some birds, when first introduced, fly towards the species which resemble them

As male birds display their fine plumage and other ornaments with so much care before the females, it is

obviously probable that these appreciate the beauty of their suitors. It is, however, difficult to obtain direct

evidence of their capacity to appreciate beauty. When birds gaze at themselves in a lookingglass (of which

many instances have been recorded) we cannot feel sure that it is not from jealousy of a supposed rival,

though this is not the conclusion of some observers. In other cases it is difficult to distinguish between mere

curiosity and admiration. It is perhaps the former feeling which, as stated by Lord Lilford (15. The 'Ibis,' vol.

ii. 1860, p. 344.), attracts the ruff towards any bright object, so that, in the Ionian Islands, "it will dart down

to a bright coloured handkerchief, regardless of repeated shots." The common lark is drawn down from the

sky, and is caught in large numbers, by a small mirror made to move and glitter in the sun. Is it admiration or

curiosity which leads the magpie, raven, and some other birds to steal and secrete bright objects, such as

Mr. Gould states that certain hummingbirds decorate the outsides of their nests "with the utmost taste; they

instinctively fasten thereon beautiful pieces of flat lichen, the larger pieces in the middle, and the smaller on

the part attached to the branch. Now and then a pretty feather is intertwined or fastened to the outer sides, the

stem being always so placed that the feather stands out beyond the surface." The best evidence, however, of a

taste for the beautiful is afforded by the three genera of Australian bowerbirds already mentioned. Their

bowers (Fig. 46), where the sexes congregate and play strange antics, are variously constructed, but what

most concerns us is, that they are decorated by the several species in a different manner. The Satin

bowerbird collects gaily coloured articles, such as the blue tailfeathers of parrakeets, bleached bones and

shells, which it sticks between the twigs or arranges at the entrance. Mr. Gould found in one bower a

neatlyworked stone tomahawk and a slip of blue cotton, evidently procured from a native encampment.

These objects are continually rearranged, and carried about by the birds whilst at play. The bower of the

Spotted bowerbird "is beautifully lined with tall grasses, so disposed that the heads nearly meet, and the

decorations are very profuse." Round stones are used to keep the grassstems in their proper places, and to

make divergent paths leading to the bower. The stones and shells are often brought from a great distance. The

Regent bird, as described by Mr. Ramsay, ornaments its short bower with bleached landshells belonging to

five or six species, and with "berries of various colours, blue, red, and black, which give it when fresh a very

pretty appearance. Besides these there were several newlypicked leaves and young shoots of a pinkish

colour, the whole showing a decided taste for the beautiful." Well may Mr. Gould say that "these highly

decorated halls of assembly must be regarded as the most wonderful instances of bird architecture yet

discovered;" and the taste, as we see, of the several species certainly differs. (16. On the ornamented nests of

hummingbirds, Gould, 'Introduction to the Trochilidae,' 1861, p. 19. On the bowerbirds, Gould, 'Handbook

to the Birds of Australia,' 1865, vol. i. pp. 444461. Ramsay, in the 'Ibis,' 1867, p. 456.)

Having made these preliminary remarks on the discrimination and taste of birds, I will give all the facts

known to me which bear on the preference shewn by the female for particular males. It is certain that distinct

species of birds occasionally pair in a state of nature and produce hybrids. Many instances could be given:

thus Macgillivray relates how a male blackbird and female thrush "fell in love with each other," and produced

offspring. (17. 'History of Brit. Birds,' vol. ii. p. 92.) Several years ago eighteen cases had been recorded of

the occurrence in Great Britain of hybrids between the black grouse and pheasant (18. 'Zoologist,'

18531854, p. 3946.); but most of these cases may perhaps be accounted for by solitary birds not finding one

of their own species to pair with. With other birds, as Mr. Jenner Weir has reason to believe, hybrids are

sometimes the result of the casual intercourse of birds building in close proximity. But these remarks do not

apply to the many recorded instances of tamed or domestic birds, belonging to distinct species, which have

become absolutely fascinated with each other, although living with their own species. Thus Waterton (19.

Waterton, 'Essays on Nat. Hist.' 2nd series, pp. 42 and 117. For the following statements see on the wigeon,

'Loudon's Mag. of Nat. Hist.' vol. ix. p. 616; L. Lloyd, 'Scandinavian Adventures,' vol. i. 1854, p. 452. Dixon,

'Ornamental and Domestic Poultry,' p. 137; Hewitt, in 'Journal of Horticulture,' Jan. 13, 1863, p. 40;

Bechstein, 'Stubenvogel,' 1840, s. 230. Mr. J. Jenner Weir has lately given me an analogous case with ducks

of two species.) states that out of a flock of twentythree Canada geese, a female paired with a solitary

Bernicle gander, although so different in appearance and size; and they produced hybrid offspring. A male

wigeon (Mareca penelope), living with females of the same species, has been known to pair with a pintail

duck, Querquedula acuta. Lloyd describes the remarkable attachment between a shielddrake (Tadorna

vulpanser) and a common duck. Many additional instances could be given; and the Rev. E.S. Dixon remarks

that "those who have kept many different species of geese together well know what unaccountable

attachments they are frequently forming, and that they are quite as likely to pair and rear young with

individuals of a race (species) apparently the most alien to themselves as with their own stock."

The Rev. W.D. Fox informs me that he possessed at the same time a pair of Chinese geese (Anser cygnoides),

and a common gander with three geese. The two lots kept quite separate, until the Chinese gander seduced

one of the common geese to live with him. Moreover, of the young birds hatched from the eggs of the

common geese, only four were pure, the other eighteen proving hybrids; so that the Chinese gander seems to

have had prepotent charms over the common gander. I will give only one other case; Mr. Hewitt states that a

wild duck, reared in captivity, "after breeding a couple of seasons with her own mallard, at once shook him

off on my placing a male Pintail on the water. It was evidently a case of love at first sight, for she swam about

the newcomer caressingly, though he appeared evidently alarmed and averse to her overtures of affection.

From that hour she forgot her old partner. Winter passed by, and the next spring the pintail seemed to have

become a convert to her blandishments, for they nested and produced seven or eight young ones."

What the charm may have been in these several cases, beyond mere novelty, we cannot even conjecture.

Colour, however, sometimes comes into play; for in order to raise hybrids from the siskin (Fringilla spinus)

and the canary, it is much the best plan, according to Bechstein, to place birds of the same tint together. Mr.

Jenner Weir turned a female canary into his aviary, where there were male linnets, goldfinches, siskins,

greenfinches, chaffinches, and other birds, in order to see which she would choose; but there never was any

doubt, and the greenfinch carried the day. They paired and produced hybrid offspring.

The fact of the female preferring to pair with one male rather than with another of the same species is not so

likely to excite attention, as when this occurs, as we have just seen, between distinct species. The former

cases can best be observed with domesticated or confined birds; but these are often pampered by high

feeding, and sometimes have their instincts vitiated to an extreme degree. Of this latter fact I could give

sufficient proofs with pigeons, and especially with fowls, but they cannot be here related. Vitiated instincts

may also account for some of the hybrid unions above mentioned; but in many of these cases the birds were

allowed to range freely over large ponds, and there is no reason to suppose that they were unnaturally

With respect to birds in a state of nature, the first and most obvious supposition which will occur to every one

is that the female at the proper season accepts the first male whom she may encounter; but she has at least the

opportunity for exerting a choice, as she is almost invariably pursued by many males. Audubonand we

must remember that he spent a long life in prowling about the forests of the United States and observing the

birds does not doubt that the female deliberately chooses her mate; thus, speaking of a woodpecker, he

says the hen is followed by halfadozen gay suitors, who continue performing strange antics, "until a

marked preference is shewn for one." The female of the redwinged starling (Agelaeus phoeniceus) is

likewise pursued by several males, "until, becoming fatigued, she alights, receives their addresses, and soon

makes a choice." He describes also how several male nightjars repeatedly plunge through the air with

astonishing rapidity, suddenly turning, and thus making a singular noise; "but no sooner has the female made

her choice than the other males are driven away." With one of the vultures (Cathartes aura) of the United

States, parties of eight, ten, or more males and females assemble on fallen logs, "exhibiting the strongest

desire to please mutually," and after many caresses, each male leads off his partner on the wing. Audubon

likewise carefully observed the wild flocks of Canada geese (Anser canadensis), and gives a graphic

description of their loveantics; he says that the birds which had been previously mated "renewed their

courtship as early as the month of January, while the others would be contending or coquetting for hours

every day, until all seemed satisfied with the choice they had made, after which, although they remained

together, any person could easily perceive that they were careful to keep in pairs. I have observed also that

the older the birds the shorter were the preliminaries of their courtship. The bachelors and old maids whether

in regret, or not caring to be disturbed by the bustle, quietly moved aside and lay down at some distance from

the rest." (20. Audubon, 'Ornithological Biography,' vol. i. pp. 191, 349; vol. ii. pp. 42, 275; vol. iii. p. 2.)

Many similar statements with respect to other birds could be cited from this same observer.

Turning now to domesticated and confined birds, I will commence by giving what little I have learnt

respecting the courtship of fowls. I have received long letters on this subject from Messrs. Hewitt and

Tegetmeier, and almost an essay from the late Mr. Brent. It will be admitted by every one that these

gentlemen, so well known from their published works, are careful and experienced observers. They do not

believe that the females prefer certain males on account of the beauty of their plumage; but some allowance

must be made for the artificial state under which these birds have long been kept. Mr. Tegetmeier is

convinced that a gamecock, though disfigured by being dubbed and with his hackles trimmed, would be

accepted as readily as a male retaining all his natural ornaments. Mr. Brent, however, admits that the beauty

of the male probably aids in exciting the female; and her acquiescence is necessary. Mr. Hewitt is convinced

that the union is by no means left to mere chance, for the female almost invariably prefers the most vigorous,

defiant, and mettlesome male; hence it is almost useless, as he remarks, "to attempt true breeding if a game

cock in good health and condition runs the locality, for almost every hen on leaving the roostingplace will

resort to the gamecock, even though that bird may not actually drive away the male of her own variety."

Under ordinary circumstances the males and females of the fowl seem to come to a mutual understanding by

means of certain gestures, described to me by Mr. Brent. But hens will often avoid the officious attentions of

young males. Old hens, and hens of a pugnacious disposition, as the same writer informs me, dislike strange

males, and will not yield until well beaten into compliance. Ferguson, however, describes how a quarrelsome

hen was subdued by the gentle courtship of a Shanghai cock. (21. 'Rare and Prize Poultry,' 1854, p. 27.)

There is reason to believe that pigeons of both sexes prefer pairing with birds of the same breed; and

dovecotpigeons dislike all the highly improved breeds. (22. 'Variation of Animals and Plants under

Domestication,' vol. ii. p. 103.) Mr. Harrison Weir has lately heard from a trustworthy observer, who keeps

blue pigeons, that these drive away all other coloured varieties, such as white, red, and yellow; and from

another observer, that a female dun carrier could not, after repeated trials, be matched with a black male, but

immediately paired with a dun. Again, Mr. Tegetmeier had a female blue turbit that obstinately refused to

pair with two males of the same breed, which were successively shut up with her for weeks; but on being let

out she would have immediately accepted the first blue dragon that offered. As she was a valuable bird, she

was then shut up for many weeks with a silver (i.e., very pale blue) male, and at last mated with him.

Nevertheless, as a general rule, colour appears to have little influence on the pairing of pigeons. Mr.

Tegetmeier, at my request, stained some of his birds with magenta, but they were not much noticed by the

Female pigeons occasionally feel a strong antipathy towards certain males, without any assignable cause.

Thus MM. Boitard and Corbie, whose experience extended over fortyfive years, state: "Quand une femelle

eprouve de l'antipathie pour un male avec lequel on veut l'accoupler, malgre tous les feux de l'amour, malgre

l'alpiste et le chenevis dont on la nourrit pour augmenter son ardeur, malgre un emprisonnement de six mois

et meme d'un an, elle refuse constamment ses caresses; les avances empressees, les agaceries, les

tournoiemens, les tendres roucoulemens, rien ne peut lui plaire ni l'emouvoir; gonflee, boudeuse, blottie dans

un coin de sa prison, elle n'en sort que pour boire et manger, ou pour repousser avec une espece de rage des

caresses devenues trop pressantes." (23. Boitard and Corbie, 'Les Pigeons,' etc., 1824, p. 12. Prosper Lucas

('Traite de l'Hered. Nat.' tom. ii. 1850, p. 296) has himself observed nearly similar facts with pigeons.) On the

other hand, Mr. Harrison Weir has himself observed, and has heard from several breeders, that a female

pigeon will occasionally take a strong fancy for a particular male, and will desert her own mate for him.

Some females, according to another experienced observer, Riedel (24. Die Taubenzucht, 1824, s. 86.), are of

a profligate disposition, and prefer almost any stranger to their own mate. Some amorous males, called by our

English fanciers "gay birds," are so successful in their gallantries, that, as Mr. H. Weir informs me, they must

Wild turkeys in the United States, according to Audubon, "sometimes pay their addresses to the domesticated

females, and are generally received by them with great pleasure." So that these females apparently prefer the

wild to their own males. (25. 'Ornithological Biography,' vol. i. p. 13. See to the same effect, Dr. Bryant, in

Here is a more curious case. Sir R. Heron during many years kept an account of the habits of the peafowl,

which he bred in large numbers. He states that "the hens have frequently great preference to a particular

peafowl. They were all so fond of an old pied cock, that one year, when he was confined, though still in view,

they were constantly assembled close to the trellicewalls of his prison, and would not suffer a japanned

peacock to touch them. On his being let out in the autumn, the oldest of the hens instantly courted him and

was successful in her courtship. The next year he was shut up in a stable, and then the hens all courted his

rival." (26. 'Proceedings, Zoological Society,' 1835, p. 54. The japanned peacock is considered by Mr. Sclater

as a distinct species, and has been named Pavo nigripennis; but the evidence seems to me to show that it is

only a variety.) This rival was a japanned or blackwinged peacock, to our eyes a more beautiful bird than

Lichtenstein, who was a good observer and had excellent opportunities of observation at the Cape of Good

Hope, assured Rudolphi that the female widowbird (Chera progne) disowns the male when robbed of the

long tail feathers with which he is ornamented during the breedingseason. I presume that this observation

must have been made on birds under confinement. (27. Rudolphi, 'Beitrage zur Anthropologie,' 1812, s. 184.)

Here is an analogous case; Dr. Jaeger (28. 'Die Darwin'sche Theorie, und ihre Stellung zu Moral und

Religion,' 1869, s. 59.), director of the Zoological Gardens of Vienna, states that a male silverpheasant, who

had been triumphant over all other males and was the accepted lover of the females, had his ornamental

plumage spoiled. He was then immediately superseded by a rival, who got the upper hand and afterwards led

It is a remarkable fact, as shewing how important colour is in the courtship of birds, that Mr. Boardman, a

wellknown collector and observer of birds for many years in the Northern United States, has never in his

large experience seen an albino paired with another bird; yet he has had opportunities of observing many

albinos belonging to several species. (29. This statement is given by Mr. A. Leith Adams, in his 'Field and

Forest Rambles,' 1873, p. 76, and accords with his own experience.) It can hardly be maintained that albinos

in a state of nature are incapable of breeding, as they can be raised with the greatest facility under

confinement. It appears, therefore, that we must attribute the fact that they do not pair to their rejection by

Female birds not only exert a choice, but in some few cases they court the male, or even fight together for his

possession. Sir R. Heron states that with peafowl, the first advances are always made by the female;

something of the same kind takes place, according to Audubon, with the older females of the wild turkey.

With the capercailzie, the females flit round the male whilst he is parading at one of the places of assemblage,

and solicit his attention. (30. In regard to peafowl, see Sir R. Heron, 'Proc. Zoolog. Soc.' 1835, p. 54, and the

Rev. E.S. Dixon, 'Ornamental Poultry,' 1848, p. 8. For the turkey, Audubon, ibid. p. 4. For the capercailzie,

Lloyd, 'Game Birds of Sweden,' 1867, p. 23.) We have seen that a tame wildduck seduced an unwilling

pintail drake after a long courtship. Mr. Bartlett believes that the Lophophorus, like many other gallinaceous

birds, is naturally polygamous, but two females cannot be placed in the same cage with a male, as they fight

so much together. The following instance of rivalry is more surprising as it relates to bullfinches, which

usually pair for life. Mr. Jenner Weir introduced a dullcoloured and ugly female into his aviary, and she

immediately attacked another mated female so unmercifully that the latter had to be separated. The new

female did all the courtship, and was at last successful, for she paired with the male; but after a time she met

with a just retribution, for, ceasing to be pugnacious, she was replaced by the old female, and the male then

In all ordinary cases the male is so eager that he will accept any female, and does not, as far as we can judge,

prefer one to the other; but, as we shall hereafter see, exceptions to this rule apparently occur in some few

groups. With domesticated birds, I have heard of only one case of males shewing any preference for certain

females, namely, that of the domestic cock, who, according to the high authority of Mr. Hewitt, prefers the

younger to the older hens. On the other hand, in effecting hybrid unions between the male pheasant and

common hens, Mr. Hewitt is convinced that the pheasant invariably prefers the older birds. He does not

appear to be in the least influenced by their colour; but "is most capricious in his attachments" (31. Mr.

Hewitt, quoted in Tegetmeier's 'Poultry Book,' 1866, p. 165.): from some inexplicable cause he shews the

most determined aversion to certain hens, which no care on the part of the breeder can overcome. Mr. Hewitt

informs me that some hens are quite unattractive even to the males of their own species, so that they may be

kept with several cocks during a whole season, and not one egg out of forty or fifty will prove fertile. On the

other hand, with the longtailed duck (Harelda glacialis), "it has been remarked," says M. Ekstrom, "that

certain females are much more courted than the rest. Frequently, indeed, one sees an individual surrounded

by six or eight amorous males." Whether this statement is credible, I know not; but the native sportsmen

shoot these females in order to stuff them as decoys. (32. Quoted in Lloyd's 'Game Birds of Sweden,' p. 345.)

With respect to female birds feeling a preference for particular males, we must bear in mind that we can

judge of choice being exerted only by analogy. If an inhabitant of another planet were to behold a number of

young rustics at a fair courting a pretty girl, and quarrelling about her like birds at one of their places of

assemblage, he would, by the eagerness of the wooers to please her and to display their finery, infer that she

had the power of choice. Now with birds the evidence stands thus: they have acute powers of observation,

and they seem to have some taste for the beautiful both in colour and sound. It is certain that the females

occasionally exhibit, from unknown causes, the strongest antipathies and preferences for particular males.

When the sexes differ in colour or in other ornaments the males with rare exceptions are the more decorated,

either permanently or temporarily during the breedingseason. They sedulously display their various

ornaments, exert their voices, and perform strange antics in the presence of the females. Even wellarmed

males, who, it might be thought, would altogether depend for success on the law of battle, are in most cases

highly ornamented; and their ornaments have been acquired at the expense of some loss of power. In other

cases ornaments have been acquired, at the cost of increased risk from birds and beasts of prey. With various

species many individuals of both sexes congregate at the same spot, and their courtship is a prolonged affair.

There is even reason to suspect that the males and females within the same district do not always succeed in

What then are we to conclude from these facts and considerations? Does the male parade his charms with so

much pomp and rivalry for no purpose? Are we not justified in believing that the female exerts a choice, and

that she receives the addresses of the male who pleases her most? It is not probable that she consciously

deliberates; but she is most excited or attracted by the most beautiful, or melodious, or gallant males. Nor

need it be supposed that the female studies each stripe or spot of colour; that the peahen, for instance, admires

each detail in the gorgeous train of the peacockshe is probably struck only by the general effect.

Nevertheless, after hearing how carefully the male Argus pheasant displays his elegant primary

wingfeathers, and erects his ocellated plumes in the right position for their full effect; or again, how the

male goldfinch alternately displays his goldbespangled wings, we ought not to feel too sure that the female

does not attend to each detail of beauty. We can judge, as already remarked, of choice being exerted, only

from analogy; and the mental powers of birds do not differ fundamentally from ours. From these various

considerations we may conclude that the pairing of birds is not left to chance; but that those males, which are

best able by their various charms to please or excite the female, are under ordinary circumstances accepted. If

this be admitted, there is not much difficulty in understanding how male birds have gradually acquired their

ornamental characters. All animals present individual differences, and as man can modify his domesticated

birds by selecting the individuals which appear to him the most beautiful, so the habitual or even occasional

preference by the female of the more attractive males would almost certainly lead to their modification; and

such modifications might in the course of time be augmented to almost any extent, compatible with the

Variability and inheritance are the foundations for the work of selection. That domesticated birds have varied

greatly, their variations being inherited, is certain. That birds in a state of nature have been modified into

distinct races is now universally admitted. (33. According to Dr. Blasius ('Ibis,' vol. ii. 1860, p. 297), there are

425 indubitable species of birds which breed in Europe, besides sixty forms, which are frequently regarded as

distinct species. Of the latter, Blasius thinks that only ten are really doubtful, and that the other fifty ought to

be united with their nearest allies; but this shews that there must be a considerable amount of variation with

some of our European birds. It is also an unsettled point with naturalists, whether several North American

birds ought to be ranked as specifically distinct from the corresponding European species. So again many

North American forms which until lately were named as distinct species, are now considered to be local

races.) Variations may be divided into two classes; those which appear to our ignorance to arise

spontaneously, and those which are directly related to the surrounding conditions, so that all or nearly all the

individuals of the same species are similarly modified. Cases of the latter kind have recently been observed

with care by Mr. J.A. Allen (34. 'Mammals and Birds of East Florida,' also an 'Ornithological Reconnaissance

of Kansas,' etc. Notwithstanding the influence of climate on the colours of birds, it is difficult to account for

the dull or dark tints of almost all the species inhabiting certain countries, for instance, the Galapagos Islands

under the equator, the wide temperate plains of Patagonia, and, as it appears, Egypt (see Mr. Hartshorne in

the 'American Naturalist,' 1873, p. 747). These countries are open, and afford little shelter to birds; but it

seems doubtful whether the absence of brightly coloured species can be explained on the principle of

protection, for on the Pampas, which are equally open, though covered by green grass, and where the birds

would be equally exposed to danger, many brilliant and conspicuously coloured species are common. I have

sometimes speculated whether the prevailing dull tints of the scenery in the above named countries may not

have affected the appreciation of bright colours by the birds inhabiting them.), who shews that in the United

States many species of birds gradually become more strongly coloured in proceeding southward, and more

lightly coloured in proceeding westward to the arid plains of the interior. Both sexes seem generally to be

affected in a like manner, but sometimes one sex more than the other. This result is not incompatible with the

belief that the colours of birds are mainly due to the accumulation of successive variations through sexual

selection; for even after the sexes have been greatly differentiated, climate might produce an equal effect on

both sexes, or a greater effect on one sex than on the other, owing to some constitutional difference.

Individual differences between the members of the same species are admitted by every one to occur under a

state of nature. Sudden and strongly marked variations are rare; it is also doubtful whether if beneficial they

would often be preserved through selection and transmitted to succeeding generations. (35. 'Origin of Species'

fifth edit. 1869, p.104. I had always perceived, that rare and stronglymarked deviations of structure,

deserving to be called monstrosities, could seldom be preserved through natural selection, and that the

preservation of even highlybeneficial variations would depend to a certain extent on chance. I had also fully

appreciated the importance of mere individual differences, and this led me to insist so strongly on the

importance of that unconscious form of selection by man, which follows from the preservation of the most

valued individuals of each breed, without any intention on his part to modify the characters of the breed. But

until I read an able article in the 'North British Review' (March 1867, p. 289, et seq.), which has been of more

use to me than any other Review, I did not see how great the chances were against the preservation of

variations, whether slight or strongly pronounced, occurring only in single individuals.) Nevertheless, it may

be worth while to give the few cases which I have been able to collect, relating chiefly to colour,simple

albinism and melanism being excluded. Mr. Gould is well known to admit the existence of few varieties, for

he esteems very slight differences as specific; yet he states (36. 'Introduction to the Trochlidae,' p. 102.) that

near Bogota certain hummingbirds belonging to the genus Cynanthus are divided into two or three races or

varieties, which differ from each other in the colouring of the tail"some having the whole of the feathers

blue, while others have the eight central ones tipped with beautiful green." It does not appear that

intermediate gradations have been observed in this or the following cases. In the males alone of one of the

Australian parrakeets "the thighs in some are scarlet, in others grassgreen." In another parrakeet of the same

country "some individuals have the band across the wingcoverts brightyellow, while in others the same

part is tinged with red. (37. Gould, 'Handbook to Birds of Australia,' vol. ii. pp. 32 and 68.) In the United

States some few of the males of the scarlet tanager (Tanagra rubra) have "a beautiful transverse band of

glowing red on the smaller wing coverts" (38. Audubon, 'Ornithological Biography,' 1838, vol. iv. p. 389.);

but this variation seems to be somewhat rare, so that its preservation through sexual selection would follow

only under usually favourable circumstances. In Bengal the Honey buzzard (Pernis cristata) has either a small

rudimental crest on its head, or none at all: so slight a difference, however, would not have been worth notice,

had not this same species possessed in Southern India a wellmarked occipital crest formed of several

graduated feathers." (39. Jerdon, 'Birds of India,' vol. i. p. 108; and Mr. Blyth, in 'Land and Water,' 1868, p.

The following case is in some respects more interesting. A pied variety of the raven, with the head, breast,

abdomen, and parts of the wings and tail feathers white, is confined to the Feroe Islands. It is not very rare

there, for Graba saw during his visit from eight to ten living specimens. Although the characters of this

variety are not quite constant, yet it has been named by several distinguished ornithologists as a distinct

species. The fact of the pied birds being pursued and persecuted with much clamour by the other ravens of

the island was the chief cause which led Brunnich to conclude that they were specifically distinct; but this is

now known to be an error. (40. Graba, 'Tagebuch Reise nach Faro,' 1830, ss. 5154. Macgillivray, 'History of

British Birds,' vol. iii. p. 745, 'Ibis,' vol. v. 1863, p. 469.) This case seems analogous to that lately given of

In various parts of the northern seas a remarkable variety of the common Guillemot (Uria troile) is found; and

in Feroe, one out of every five birds, according to Graba's estimation, presents this variation. It is

characterised (41. Graba, ibid. s. 54. Macgillivray, ibid. vol. v. p. 327.) by a pure white ring round the eye,

with a curved narrow white line, an inch and a half in length, extending back from the ring. This conspicuous

character has caused the bird to be ranked by several ornithologists as a distinct species under the name of U.

lacrymans, but it is now known to be merely a variety. It often pairs with the common kind, yet intermediate

gradations have never been seen; nor is this surprising, for variations which appear suddenly, are often, as I

have elsewhere shewn (42. 'Variation of Animals and Plants under Domestication,' vol. ii. p. 92.), transmitted

either unaltered or not at all. We thus see that two distinct forms of the same species may coexist in the

same district, and we cannot doubt that if the one had possessed any advantage over the other, it would soon

have been multiplied to the exclusion of the latter. If, for instance, the male pied ravens, instead of being

persecuted by their comrades, had been highly attractive (like the above pied peacock) to the black female

ravens their numbers would have rapidly increased. And this would have been a case of sexual selection.

With respect to the slight individual differences which are common, in a greater or less degree, to all the

members of the same species, we have every reason to believe that they are by far the most important for the

work of selection. Secondary sexual characters are eminently liable to vary, both with animals in a state of

nature and under domestication. (43. On these points see also 'Variation of Animals and Plants under

Domestication,' vol. i. p. 253; vol ii. pp. 73, 75.) There is also reason to believe, as we have seen in our eighth

chapter, that variations are more apt to occur in the male than in the female sex. All these contingencies are

highly favourable for sexual selection. Whether characters thus acquired are transmitted to one sex or to both

sexes, depends, as we shall see in the following chapter, on the form of inheritance which prevails.

It is sometimes difficult to form an opinion whether certain slight differences between the sexes of birds are

simply the result of variability with sexuallylimited inheritance, without the aid of sexual selection, or

whether they have been augmented through this latter process. I do not here refer to the many instances where

the male displays splendid colours or other ornaments, of which the female partakes to a slight degree; for

these are almost certainly due to characters primarily acquired by the male having been more or less

transferred to the female. But what are we to conclude with respect to certain birds in which, for instance, the

eyes differ slightly in colour in the two sexes? (44. See, for instance, on the irides of a Podica and Gallicrex

in 'Ibis,' vol. ii. 1860, p. 206; and vol. v. 1863, p. 426.) In some cases the eyes differ conspicuously; thus with

the storks of the genus Xenorhynchus, those of the male are blackish hazel, whilst those of the females are

gambogeyellow; with many hornbills (Buceros), as I hear from Mr. Blyth (45. See also Jerdon, 'Birds of

India,' vol. i. pp. 243245.), the males have intense crimson eyes, and those of the females are white. In the

Buceros bicornis, the hind margin of the casque and a stripe on the crest of the beak are black in the male, but

not so in the female. Are we to suppose that these black marks and the crimson colour of the eyes have been

preserved or augmented through sexual selection in the males? This is very doubtful; for Mr. Bartlett shewed

me in the Zoological Gardens that the inside of the mouth of this Buceros is black in the male and

fleshcoloured in the female; and their external appearance or beauty would not be thus affected. I observed

in Chile (46. 'Zoology of the Voyage of H.M.S. "Beagle,"' 1841, p. 6.) that the iris in the condor, when about

a year old, is darkbrown, but changes at maturity into yellowishbrown in the male, and into bright red in

the female. The male has also a small, longitudinal, leadencoloured, fleshy crest or comb. The comb of

many gallinaceous birds is highly ornamental, and assumes vivid colours during the act of courtship; but

what are we to think of the dull coloured comb of the condor, which does not appear to us in the least

ornamental? The same question may be asked in regard to various other characters, such as the knob on the

base of the beak of the Chinese goose (Anser cygnoides), which is much larger in the male than in the female.

No certain answer can be given to these questions; but we ought to be cautious in assuming that knobs and

various fleshy appendages cannot be attractive to the female, when we remember that with savage races of

man various hideous deformitiesdeep scars on the face with the flesh raised into protuberances, the septum

of the nose pierced by sticks or bones, holes in the ears and lips stretched widely openare all admired as

Whether or not unimportant differences between the sexes, such as those just specified, have been preserved

through sexual selection, these differences, as well as all others, must primarily depend on the laws of

variation. On the principle of correlated development, the plumage often varies on different parts of the body,

or over the whole body, in the same manner. We see this well illustrated in certain breeds of the fowl. In all

the breeds the feathers on the neck and loins of the males are elongated, and are called hackles; now when

both sexes acquire a topknot, which is a new character in the genus, the feathers on the head of the male

become hackleshaped, evidently on the principle of correlation; whilst those on the head of the female are of

the ordinary shape. The colour also of the hackles forming the topknot of the male, is often correlated with

that of the hackles on the neck and loins, as may be seen by comparing these feathers in the golden and

silverspangled Polish, the Houdans, and Crevecoeur breeds. In some natural species we may observe

exactly the same correlation in the colours of these same feathers, as in the males of the splendid Gold and

The structure of each individual feather generally causes any change in its colouring to be symmetrical; we

see this in the various laced, spangled, and pencilled breeds of the fowl; and on the principle of correlation

the feathers over the whole body are often coloured in the same manner. We are thus enabled without much

trouble to rear breeds with their plumage marked almost as symmetrically as in natural species. In laced and

spangled fowls the coloured margins of the feathers are abruptly defined; but in a mongrel raised by me from

a black Spanish cock glossed with green, and a white gamehen, all the feathers were greenishblack,

excepting towards their extremities, which were yellowishwhite; but between the white extremities and the

black bases, there was on each feather a symmetrical, curved zone of darkbrown. In some instances the shaft

of the feather determines the distribution of the tints; thus with the bodyfeathers of a mongrel from the same

black Spanish cock and a silverspangled Polish hen, the shaft, together with a narrow space on each side,

was greenishblack, and this was surrounded by a regular zone of darkbrown, edged with brownishwhite.

In these cases we have feathers symmetrically shaded, like those which give so much elegance to the

plumage of many natural species. I have also noticed a variety of the common pigeon with the wingbars

symmetrically zoned with three bright shades, instead of being simply black on a slatyblue ground, as in the

In many groups of birds the plumage is differently coloured in the several species, yet certain spots, marks, or

stripes are retained by all. Analogous cases occur with the breeds of the pigeon, which usually retain the two

wingbars, though they may be coloured red, yellow, white, black, or blue, the rest of the plumage being of

some wholly different tint. Here is a more curious case, in which certain marks are retained, though coloured

in a manner almost exactly the opposite of what is natural; the aboriginal pigeon has a blue tail, with the

terminal halves of the outer webs of the two outer tail feathers white; now there is a subvariety having a

white instead of a blue tail, with precisely that part black which is white in the parentspecies. (47. Bechstein,

'Naturgeschichte Deutschlands,' B. iv. 1795, s. 31, on a subvariety of the Monck pigeon.)

[Fig. 53. Cyllo leda, Linn., from a drawing by Mr. Trimen, shewing the extreme range of variation in the

ocelli. A. Specimen, from Mauritius, upper surface of forewing. A1. Specimen, from Natal, ditto. B.

Specimen, from Java, upper surface of hindwing. B1. Specimen, from Mauritius, ditto.]

As no ornaments are more beautiful than the ocelli on the feathers of various birds, on the hairy coats of some

mammals, on the scales of reptiles and fishes, on the skin of amphibians, on the wings of many Lepidoptera

and other insects, they deserve to be especially noticed. An ocellus consists of a spot within a ring of another

colour, like the pupil within the iris, but the central spot is often surrounded by additional concentric zones.

The ocelli on the tailcoverts of the peacock offer a familiar example, as well as those on the wings of the

peacockbutterfly (Vanessa). Mr. Trimen has given me a description of a S. African moth (Gynanisa isis),

allied to our Emperor moth, in which a magnificent ocellus occupies nearly the whole surface of each hinder

wing; it consists of a black centre, including a semitransparent crescentshaped mark, surrounded by

successive, ochreyellow, black, ochreyellow, pink, white, pink, brown, and whitish zones. Although we do

not know the steps by which these wonderfully beautiful and complex ornaments have been developed, the

process has probably been a simple one, at least with insects; for, as Mr. Trimen writes to me, "no characters

of mere marking or coloration are so unstable in the Lepidoptera as the ocelli, both in number and size." Mr.

Wallace, who first called my attention to this subject, shewed me a series of specimens of our common

meadowbrown butterfly (Hipparchia janira) exhibiting numerous gradations from a simple minute black

spot to an elegantlyshaded ocellus. In a S. African butterfly (Cyllo leda, Linn.), belonging to the same

family, the ocelli are even still more variable. In some specimens (A, Fig. 53) large spaces on the upper

surface of the wings are coloured black, and include irregular white marks; and from this state a complete

gradation can be traced into a tolerably perfect ocellus (A1), and this results from the contraction of the

irregular blotches of colour. In another series of specimens a gradation can be followed from excessively

minute white dots, surrounded by a scarcely visible black line (B), into perfectly symmetrical and large ocelli

(B1). (48. This woodcut has been engraved from a beautiful drawing, most kindly made for me by Mr.

Trimen; see also his description of the wonderful amount of variation in the coloration and shape of the wings

of this butterfly, in his 'Rhopalocera Africae Australis,' p. 186.) In cases like these, the development of a

With birds and many other animals, it seems to follow from the comparison of allied species that circular

spots are often generated by the breaking up and contraction of stripes. In the Tragopan pheasant faint white

lines in the female represent the beautiful white spots in the male (49. Jerdon, 'Birds of India,' vol. iii. p.

517.); and something of the same kind may be observed in the two sexes of the Argus pheasant. However this

may be, appearances strongly favour the belief that on the one hand, a dark spot is often formed by the

colouring matter being drawn towards a central point from a surrounding zone, which latter is thus rendered

lighter; and, on the other hand, that a white spot is often formed by the colour being driven away from a

central point, so that it accumulates in a surrounding darker zone. In either case an ocellus is the result. The

colouring matter seems to be a nearly constant quantity, but is redistributed, either centripetally or

centrifugally. The feathers of the common guineafowl offer a good instance of white spots surrounded by

darker zones; and wherever the white spots are large and stand near each other, the surrounding dark zones

become confluent. In the same wingfeather of the Argus pheasant dark spots may be seen surrounded by a

pale zone, and white spots by a dark zone. Thus the formation of an ocellus in its most elementary state

appears to be a simple affair. By what further steps the more complex ocelli, which are surrounded by many

successive zones of colour, have been generated, I will not pretend to say. But the zoned feathers of the

mongrels from differently coloured fowls, and the extraordinary variability of the ocelli on many

Lepidoptera, lead us to conclude that their formation is not a complex process, but depends on some slight

[Fig. 54. Feather of Peacock, about twothirds of natural size, drawn by Mr. Ford. The transparent zone is

represented by the outermost white zone, confined to the upper end of the disc.]

Cases of gradation are important, as shewing us that highly complex ornaments may be acquired by small

successive steps. In order to discover the actual steps by which the male of any existing bird has acquired his

magnificent colours or other ornaments, we ought to behold the long line of his extinct progenitors; but this is

obviously impossible. We may, however, generally gain a clue by comparing all the species of the same

group, if it be a large one; for some of them will probably retain, at least partially, traces of their former

characters. Instead of entering on tedious details respecting various groups, in which striking instances of

gradation could be given, it seems the best plan to take one or two strongly marked cases, for instance that of

the peacock, in order to see if light can be thrown on the steps by which this bird bas become so splendidly

decorated. The peacock is chiefly remarkable from the extraordinary length of his tailcoverts; the tail itself

not being much elongated. The barbs along nearly the whole length of these feathers stand separate or are

decomposed; but this is the case with the feathers of many species, and with some varieties of the domestic

fowl and pigeon. The barbs coalesce towards the extremity of the shaft forming the oval disc or ocellus,

which is certainly one of the most beautiful objects in the world. It consists of an iridescent, intensely blue,

indented centre, surrounded by a rich green zone, this by a broad copperybrown zone, and this by five other

narrow zones of slightly different iridescent shades. A trifling character in the disc deserves notice; the barbs,

for a space along one of the concentric zones are more or less destitute of their barbules, so that a part of the

disc is surrounded by an almost transparent zone, which gives it a highly finished aspect. But I have

elsewhere described (50. 'Variation of Animals and Plants under Domestication,' vol. i. p. 254.) an exactly

analogous variation in the hackles of a subvariety of the game cock, in which the tips, having a metallic

lustre, "are separated from the lower part of the feather by a symmetrically shaped transparent zone,

composed of the naked portions of the barbs." The lower margin or base of the darkblue centre of the

ocellus is deeply indented on the line of the shaft. The surrounding zones likewise shew traces, as may be

seen in the drawing (Fig. 54), of indentations, or rather breaks. These indentations are common to the Indian

and Javan peacocks (Pavo cristatus and P. muticus); and they seem to deserve particular attention, as

probably connected with the development of the ocellus; but for a long time I could not conjecture their

If we admit the principle of gradual evolution, there must formerly have existed many species which

presented every successive step between the wonderfully elongated tailcoverts of the peacock and the short

tail coverts of all ordinary birds; and again between the magnificent ocelli of the former, and the simpler

ocelli or mere coloured spots on other birds; and so with all the other characters of the peacock. Let us look to

the allied Gallinaceae for any stillexisting gradations. The species and sub species of Polyplectron inhabit

countries adjacent to the native land of the peacock; and they so far resemble this bird that they are

sometimes called peacockpheasants. I am also informed by Mr. Bartlett that they resemble the peacock in

their voice and in some of their habits. During the spring the males, as previously described, strut about

before the comparatively plaincoloured females, expanding and erecting their tail and wingfeathers, which

are ornamented with numerous ocelli. I request the reader to turn back to the drawing (Fig. 51) of a

Polyplectron; In P. napoleonis the ocelli are confined to the tail, and the back is of a rich metallic blue; in

which respects this species approaches the Java peacock. P. hardwickii possesses a peculiar topknot, which

is also somewhat like that of the Java peacock. In all the species the ocelli on the wings and tail are either

circular or oval, and consist of a beautiful, iridescent, greenishblue or greenishpurple disc, with a black

border. This border in P. chinquis shades into brown, edged with cream colour, so that the ocellus is here

surrounded with variously shaded, though not bright, concentric zones. The unusual length of the tailcoverts

is another remarkable character in Polyplectron; for in some of the species they are half, and in others

twothirds as long as the true tailfeathers. The tailcoverts are ocellated as in the peacock. Thus the several

species of Polyplectron manifestly make a graduated approach to the peacock in the length of their

[Fig. 55. Part of a tailcovert of Polyplectron chinquis, with the two ocelli of natural size.

Fig. 56. Part of a tailcovert of Polyplectron malaccense, with the two ocelli, partially confluent, of natural

Notwithstanding this approach, the first species of Polyplectron which I examined almost made me give up

the search; for I found not only that the true tailfeathers, which in the peacock are quite plain, were

ornamented with ocelli, but that the ocelli on all the feathers differed fundamentally from those of the

peacock, in there being two on the same feather (Fig. 55), one on each side of the shaft. Hence I concluded

that the early progenitors of the peacock could not have resembled a Polyplectron. But on continuing my

search, I observed that in some of the species the two ocelli stood very near each other; that in the

tailfeathers of P. hardwickii they touched each other; and, finally, that on the tailcoverts of this same

species as well as of P. malaccense (Fig. 56) they were actually confluent. As the central part alone is

confluent, an indentation is left at both the upper and lower ends; and the surrounding coloured zones are

likewise indented. A single ocellus is thus formed on each tailcovert, though still plainly betraying its

double origin. These confluent ocelli differ from the single ocelli of the peacock in having an indentation at

both ends, instead of only at the lower or basal end. The explanation, however, of this difference is not

difficult; in some species of Polyplectron the two oval ocelli on the same feather stand parallel to each other;

in other species (as in P. chinquis) they converge towards one end; now the partial confluence of two

convergent ocelli would manifestly leave a much deeper indentation at the divergent than at the convergent

end. It is also manifest that if the convergence were strongly pronounced and the confluence complete, the

The tailfeathers in both species of the peacock are entirely destitute of ocelli, and this apparently is related

to their being covered up and concealed by the long tailcoverts. In this respect they differ remarkably from

the tailfeathers of Polyplectron, which in most of the species are ornamented with larger ocelli than those on

the tailcoverts. Hence I was led carefully to examine the tailfeathers of the several species, in order to

discover whether their ocelli shewed any tendency to disappear; and to my great satisfaction, this appeared to

be so. The central tailfeathers of P. napoleonis have the two ocelli on each side of the shaft perfectly

developed; but the inner ocellus becomes less and less conspicuous on the more exterior tailfeathers, until a

mere shadow or rudiment is left on the inner side of the outermost feather. Again, in P. malaccense, the ocelli

on the tailcoverts are, as we have seen, confluent; and these feathers are of unusual length, being twothirds

of the length of the tailfeathers, so that in both these respects they approach the tailcoverts of the peacock.

Now in P. malaccense, the two central tailfeathers alone are ornamented, each with two brightlycoloured

ocelli, the inner ocellus having completely disappeared from all the other tailfeathers. Consequently the

tail coverts and tailfeathers of this species of Polyplectron make a near approach in structure and

As far, then, as gradation throws light on the steps by which the magnificent train of the peacock has been

acquired, hardly anything more is needed. If we picture to ourselves a progenitor of the peacock in an almost

exactly intermediate condition between the existing peacock, with his enormously elongated tailcoverts,

ornamented with single ocelli, and an ordinary gallinaceous bird with short tailcoverts, merely spotted with

some colour, we shall see a bird allied to Polyplectronthat is, with tailcoverts, capable of erection and

expansion, ornamented with two partially confluent ocelli, and long enough almost to conceal the tail

feathers, the latter having already partially lost their ocelli. The indentation of the central disc and of the

surrounding zones of the ocellus, in both species of peacock, speaks plainly in favour of this view, and is

otherwise inexplicable. The males of Polyplectron are no doubt beautiful birds, but their beauty, when viewed

from a little distance, cannot be compared with that of the peacock. Many female progenitors of the peacock

must, during a long line of descent, have appreciated this superiority; for they have unconsciously, by the

continued preference for the most beautiful males, rendered the peacock the most splendid of living birds.

Another excellent case for investigation is offered by the ocelli on the wingfeathers of the Argus pheasant,

which are shaded in so wonderful a manner as to resemble balls lying loose within sockets, and consequently

differ from ordinary ocelli. No one, I presume, will attribute the shading, which has excited the admiration of

many experienced artists, to chanceto the fortuitous concourse of atoms of colouring matter. That these

ornaments should have been formed through the selection of many successive variations, not one of which

was originally intended to produce the ballandsocket effect, seems as incredible as that one of Raphael's

Madonnas should have been formed by the selection of chance daubs of paint made by a long succession of

young artists, not one of whom intended at first to draw the human figure. In order to discover how the ocelli

have been developed, we cannot look to a long line of progenitors, nor to many closelyallied forms, for such

do not now exist. But fortunately the several feathers on the wing suffice to give us a clue to the problem, and

they prove to demonstration that a gradation is at least possible from a mere spot to a finished

[Fig. 57. Part of secondary wingfeather of Argus pheasant, shewing two perfect ocelli, a and b. A, B, C, D,

etc., are dark stripes running obliquely down, each to an ocellus. [Much of the web on both sides, especially

Fig.59. Portion of one of the secondary wingfeathers near to the body, shewing the socalled elliptic

ornaments. The righthand figure is given merely as a diagram for the sake of the letters of reference. A, B,

C, D, etc. Rows of spots running down to and forming the elliptic ornaments. b. Lowest spot or mark in row

B. c. The next succeeding spot or mark in the same row. d. Apparently a broken prolongation of the spot c. in

The wingfeathers, bearing the ocelli, are covered with dark stripes (Fig. 57) or with rows of dark spots (Fig.

59), each stripe or row of spots running obliquely down the outer side of the shaft to one of the ocelli. The

spots are generally elongated in a line transverse to the row in which they stand. They often become confluent

either in the line of the rowand then they form a longitudinal stripeor transversely, that is, with the spots

in the adjoining rows, and then they form transverse stripes. A spot sometimes breaks up into smaller spots,

It will be convenient first to describe a perfect ballandsocket ocellus. This consists of an intensely black

circular ring, surrounding a space shaded so as exactly to resemble a ball. The figure here given has been

admirably drawn by Mr. Ford and well engraved, but a woodcut cannot exhibit the exquisite shading of the

original. The ring is almost always slightly broken or interrupted (Fig. 57) at a point in the upper half, a little

to the right of and above the white shade on the enclosed ball; it is also sometimes broken towards the base

on the right hand. These little breaks have an important meaning. The ring is always much thickened, with the

edges illdefined towards the lefthand upper corner, the feather being held erect, in the position in which it

is here drawn. Beneath this thickened part there is on the surface of the ball an oblique almost pure white

mark, which shades off downwards into a paleleaden hue, and this into yellowish and brown tints, which

insensibly become darker and darker towards the lower part of the ball. It is this shading which gives so

admirably the effect of light shining on a convex surface. If one of the balls be examined, it will be seen that

the lower part is of a brown tint and is indistinctly separated by a curved oblique line from the upper part,

which is yellower and more leaden; this curved oblique line runs at right angles to the longer axis of the white

patch of light, and indeed of all the shading; but this difference in colour, which cannot of course be shewn in

the woodcut, does not in the least interfere with the perfect shading of the ball. It should be particularly

observed that each ocellus stands in obvious connection either with a dark stripe, or with a longitudinal row

of dark spots, for both occur indifferently on the same feather. Thus in Fig. 57 stripe A runs to ocellus a; B

runs to ocellus b; stripe C is broken in the upper part, and runs down to the next succeeding ocellus, not

represented in the woodcut; D to the next lower one, and so with the stripes E and F. Lastly, the several ocelli

I will next describe the other extreme of the series, namely, the first trace of an ocellus. The short secondary

wingfeather (Fig. 58), nearest to the body, is marked like the other feathers, with oblique, longitudinal,

rather irregular, rows of very dark spots. The basal spot, or that nearest the shaft, in the five lower rows

(excluding the lowest one) is a little larger than the other spots of the same row, and a little more elongated in

a transverse direction. It differs also from the other spots by being bordered on its upper side with some dull

fulvous shading. But this spot is not in any way more remarkable than those on the plumage of many birds,

and might easily be overlooked. The next higher spot does not differ at all from the upper ones in the same

row. The larger basal spots occupy exactly the same relative position on these feathers as do the perfect ocelli

By looking to the next two or three succeeding wingfeathers, an absolutely insensible gradation can be

traced from one of the lastdescribed basal spots, together with the next higher one in the same row, to a

curious ornament, which cannot be called an ocellus, and which I will name, from the want of a better term,

an "elliptic ornament." These are shewn in the accompanying figure (Fig. 59). We here see several oblique

rows, A, B, C, D, etc. (see the lettered diagram on the right hand), of dark spots of the usual character. Each

row of spots runs down to and is connected with one of the elliptic ornaments, in exactly the same manner as

each stripe in Fig. 57 runs down to and is connected with one of the ballandsocket ocelli. Looking to any

one row, for instance, B, in Fig. 59, the lowest mark (b) is thicker and considerably longer than the upper

spots, and has its left extremity pointed and curved upwards. This black mark is abruptly bordered on its

upper side by a rather broad space of richly shaded tints, beginning with a narrow brown zone, which passes

into orange, and this into a pale leaden tint, with the end towards the shaft much paler. These shaded tints

together fill up the whole inner space of the elliptic ornament. The mark (b) corresponds in every respect with

the basal shaded spot of the simple feather described in the last paragraph (Fig. 58), but is more highly

developed and more brightly coloured. Above and to the right of this spot (b, Fig. 59), with its bright shading,

there is a long narrow, black mark (c), belonging to the same row, and which is arched a little downwards so

as to face (b). This mark is sometimes broken into two portions. It is also narrowly edged on the lower side

with a fulvous tint. To the left of and above c, in the same oblique direction, but always more or less distinct

from it, there is another black mark (d). This mark is generally subtriangular and irregular in shape, but in

the one lettered in the diagram it is unusually narrow, elongated, and regular. It apparently consists of a

lateral and broken prolongation of the mark (c), together with its confluence with a broken and prolonged part

of the next spot above; but I do not feel sure of this. These three marks, b, c, and d, with the intervening

bright shades, form together the socalled elliptic ornament. These ornaments placed parallel to the shaft,

manifestly correspond in position with the ballandsocket ocelli. Their extremely elegant appearance cannot

be appreciated in the drawing, as the orange and leaden tints, contrasting so well with the black marks, cannot

[Fig. 60. An ocellus in an intermediate condition between the elliptic ornament and the perfect

Between one of the elliptic ornaments and a perfect ballandsocket ocellus, the gradation is so perfect that it

is scarcely possible to decide when the latter term ought to be used. The passage from the one into the other is

effected by the elongation and greater curvature in opposite directions of the lower black mark (b, Fig. 59),

and more especially of the upper one (c), together with the contraction of the elongated sub triangular or

narrow mark (d), so that at last these three marks become confluent, forming an irregular elliptic ring. This

ring is gradually rendered more and more circular and regular, increasing at the same time in diameter. I have

here given a drawing (Fig. 60) of the natural size of an ocellus not as yet quite perfect. The lower part of the

black ring is much more curved than is the lower mark in the elliptic ornament (b, Fig. 59). The upper part of

the ring consists of two or three separate portions; and there is only a trace of the thickening of the portion

which forms the black mark above the white shade. This white shade itself is not as yet much concentrated;

and beneath it the surface is brighter coloured than in a perfect ballandsocket ocellus. Even in the most

perfect ocelli traces of the junction of three or four elongated black marks, by which the ring has been

formed, may often be detected. The irregular subtriangular or narrow mark (d, Fig. 59), manifestly forms,

by its contraction and equalisation, the thickened portion of the ring above the white shade on a perfect

ballandsocket ocellus. The lower part of the ring is invariably a little thicker than the other parts (Fig. 57),

and this follows from the lower black mark of the elliptic ornament (b, Fig. 59) having originally been thicker

than the upper mark (c). Every step can be followed in the process of confluence and modification; and the

black ring which surrounds the ball of the ocellus is unquestionably formed by the union and modification of

the three black marks, b, c, d, of the elliptic ornament. The irregular zigzag black marks between the

successive ocelli (Fig. 57) are plainly due to the breaking up of the somewhat more regular but similar marks

The successive steps in the shading of the ballandsocket ocelli can be followed out with equal clearness.

The brown, orange, and paleleadened narrow zones, which border the lower black mark of the elliptic

ornament, can be seen gradually to become more and more softened and shaded into each other, with the

upper lighter part towards the lefthand corner rendered still lighter, so as to become almost white, and at the

same time more contracted. But even in the most perfect ballandsocket ocelli a slight difference in the

tints, though not in the shading, between the upper and lower parts of the ball can be perceived, as before

noticed; and the line of separation is oblique, in the same direction as the bright coloured shades of the

elliptic ornaments. Thus almost every minute detail in the shape and colouring of the ballandsocket ocelli

can be shewn to follow from gradual changes in the elliptic ornaments; and the development of the latter can

be traced by equally small steps from the union of two almost simple spots, the lower one (Fig. 58) having

[Fig. 61. Portion near summit of one of the secondary wingfeathers, bearing perfect ballandsocket ocelli.

a. Ornamented upper part. b. Uppermost, imperfect ballandsocket ocellus. (The shading above the white

mark on the summit of the ocellus is here a little too dark.) c. Perfect ocellus.]

The extremities of the longer secondary feathers which bear the perfect ballandsocket ocelli, are peculiarly

ornamented (Fig. 61). The oblique longitudinal stripes suddenly cease upwards and become confused; and

above this limit the whole upper end of the feather (a) is covered with white dots, surrounded by little black

rings, standing on a dark ground. The oblique stripe belonging to the uppermost ocellus (b) is barely

represented by a very short irregular black mark with the usual, curved, transverse base. As this stripe is thus

abruptly cut off, we can perhaps understand from what has gone before, how it is that the upper thickened

part of the ring is here absent; for, as before stated, this thickened part apparently stands in some relation with

a broken prolongation from the next higher spot. From the absence of the upper and thickened part of the

ring, the uppermost ocellus, though perfect in all other respects, appears as if its top had been obliquely sliced

off. It would, I think, perplex any one, who believes that the plumage of the Argus pheasant was created as

we now see it, to account for the imperfect condition of the uppermost ocellus. I should add that on the

secondary wingfeather farthest from the body all the ocelli are smaller and less perfect than on the other

feathers, and have the upper part of the ring deficient, as in the case just mentioned. The imperfection here

seems to be connected with the fact that the spots on this feather shew less tendency than usual to become

confluent into stripes; they are, on the contrary, often broken up into smaller spots, so that two or three rows

There still remains another very curious point, first observed by Mr. T.W. Wood (51. The 'Field,' May 28,

1870.), which deserves attention. In a photograph, given me by Mr. Ward, of a specimen mounted as in the

act of display, it may be seen that on the feathers which are held perpendicularly, the white marks on the

ocelli, representing light reflected from a convex surface, are at the upper or further end, that is, are directed

upwards; and the bird whilst displaying himself on the ground would naturally be illuminated from above.

But here comes the curious point; the outer feathers are held almost horizontally, and their ocelli ought

likewise to appear as if illuminated from above, and consequently the white marks ought to be placed on the

upper sides of the ocelli; and, wonderful as is the fact, they are thus placed! Hence the ocelli on the several

feathers, though occupying very different positions with respect to the light, all appear as if illuminated from

above, just as an artist would have shaded them. Nevertheless they are not illuminated from strictly the same

point as they ought to be; for the white marks on the ocelli of the feathers which are held almost horizontally,

are placed rather too much towards the further end; that is, they are not sufficiently lateral. We have,

however, no right to expect absolute perfection in a part rendered ornamental through sexual selection, any

more than we have in a part modified through natural selection for real use; for instance, in that wondrous

organ the human eye. And we know what Helmholtz, the highest authority in Europe on the subject, has said

about the human eye; that if an optician had sold him an instrument so carelessly made, he would have

thought himself fully justified in returning it. (52. 'Popular Lectures on Scientific Subjects,' Eng. trans. 1873,

We have now seen that a perfect series can be followed, from simple spots to the wonderful ballandsocket

ornaments. Mr. Gould, who kindly gave me some of these feathers, fully agrees with me in the completeness

of the gradation. It is obvious that the stages in development exhibited by the feathers on the same bird do not

at all necessarily shew us the steps passed through by the extinct progenitors of the species; but they probably

give us the clue to the actual steps, and they at least prove to demonstration that a gradation is possible.

Bearing in mind how carefully the male Argus pheasant displays his plumes before the female, as well as the

many facts rendering it probable that female birds prefer the more attractive males, no one who admits the

agency of sexual selection in any case will deny that a simple dark spot with some fulvous shading might be

converted, through the approximation and modification of two adjoining spots, together with some slight

increase of colour, into one of the so called elliptic ornaments. These latter ornaments have been shewn to

many persons, and all have admitted that they are beautiful, some thinking them even more so than the

ballandsocket ocelli. As the secondary plumes became lengthened through sexual selection, and as the

elliptic ornaments increased in diameter, their colours apparently became less bright; and then the

ornamentation of the plumes had to be gained by an improvement in the pattern and shading; and this process

was carried on until the wonderful ballandsocket ocelli were finally developed. Thus we can

understandand in no other way as it seems to methe present condition and origin of the ornaments on

From the light afforded by the principle of gradationfrom what we know of the laws of variationfrom

the changes which have taken place in many of our domesticated birdsand, lastly, from the character (as

we shall hereafter see more clearly) of the immature plumage of young birdswe can sometimes indicate,

with a certain amount of confidence, the probable steps by which the males have acquired their brilliant

plumage and various ornaments; yet in many cases we are involved in complete darkness. Mr. Gould several

years ago pointed out to me a hummingbird, the Urosticte benjamini, remarkable for the curious differences

between the sexes. The male, besides a splendid gorget, has greenishblack tailfeathers, with the four

CENTRAL ones tipped with white; in the female, as with most of the allied species, the three OUTER

tailfeathers on each side are tipped with white, so that the male has the four central, whilst the female has

the six exterior feathers ornamented with white tips. What makes the case more curious is that, although the

colouring of the tail differs remarkably in both sexes of many kinds of hummingbirds, Mr. Gould does not

know a single species, besides the Urosticte, in which the male has the four central feathers tipped with white.

The Duke of Argyll, in commenting on this case (53. 'The Reign of Law,' 1867, p. 247.), passes over sexual

selection, and asks, "What explanation does the law of natural selection give of such specific varieties as

these?" He answers "none whatever"; and I quite agree with him. But can this be so confidently said of sexual

selection? Seeing in how many ways the tailfeathers of hummingbirds differ, why should not the four

central feathers have varied in this one species alone, so as to have acquired white tips? The variations may

have been gradual, or somewhat abrupt as in the case recently given of the hummingbirds near Bogota, in

which certain individuals alone have the "central tailfeathers tipped with beautiful green." In the female of

the Urosticte I noticed extremely minute or rudimental white tips to the two outer of the four central black

tail feathers; so that here we have an indication of change of some kind in the plumage of this species. If we

grant the possibility of the central tail feathers of the male varying in whiteness, there is nothing strange in

such variations having been sexually selected. The white tips, together with the small white eartufts,

certainly add, as the Duke of Argyll admits, to the beauty of the male; and whiteness is apparently

appreciated by other birds, as may be inferred from such cases as the snowwhite male of the Bellbird. The

statement made by Sir R. Heron should not be forgotten, namely, that his peahens, when debarred from

access to the pied peacock, would not unite with any other male, and during that season produced no

offspring. Nor is it strange that variations in the tailfeathers of the Urosticte should have been specially

selected for the sake of ornament, for the next succeeding genus in the family takes its name of Metallura

from the splendour of these feathers. We have, moreover, good evidence that hummingbirds take especial

pains in displaying their tailfeathers; Mr. Belt (54. 'The Naturalist in Nicaragua,' 1874, p. 112.), after

describing the beauty of the Florisuga mellivora, says, "I have seen the female sitting on a branch, and two

males displaying their charms in front of her. One would shoot up like a rocket, then suddenly expanding the

snowwhite tail, like an inverted parachute, slowly descend in front of her, turning round gradually to shew

off back and front...The expanded white tail covered more space than all the rest of the bird, and was

evidently the grand feature in the performance. Whilst one male was descending, the other would shoot up

and come slowly down expanded. The entertainment would end in a fight between the two performers; but

whether the most beautiful or the most pugnacious was the accepted suitor, I know not." Mr. Gould, after

describing the peculiar plumage of the Urosticte, adds, "that ornament and variety is the sole object, I have

myself but little doubt." (55. 'Introduction to the Trochilidae,' 1861, p. 110.) If this be admitted, we can

perceive that the males which during former times were decked in the most elegant and novel manner would

have gained an advantage, not in the ordinary struggle for life, but in rivalry with other males, and would

Discussion as to why the males alone of some species, and both sexes of others, are brightly colouredOn

sexuallylimited inheritance, as applied to various structures and to brightlycoloured

plumageNidification in relation to colourLoss of nuptial plumage during the winter.

We have in this chapter to consider why the females of many birds have not acquired the same ornaments as

the male; and why, on the other hand, both sexes of many other birds are equally, or almost equally,

ornamented? In the following chapter we shall consider the few cases in which the female is more

In my 'Origin of Species' (1. Fourth edition, 1866, p. 241.) I briefly suggested that the long tail of the peacock

would be inconvenient and the conspicuous black colour of the male capercailzie dangerous, to the female

during the period of incubation: and consequently that the transmission of these characters from the male to

the female offspring had been checked through natural selection. I still think that this may have occurred in

some few instances: but after mature reflection on all the facts which I have been able to collect, I am now

inclined to believe that when the sexes differ, the successive variations have generally been from the first

limited in their transmission to the same sex in which they first arose. Since my remarks appeared, the subject

of sexual coloration has been discussed in some very interesting papers by Mr. Wallace (2. 'Westminster

Review,' July 1867. 'Journal of Travel,' vol. i. 1868, p. 73.), who believes that in almost all cases the

successive variations tended at first to be transmitted equally to both sexes; but that the female was saved,

through natural selection, from acquiring the conspicuous colours of the male, owing to the danger which she

This view necessitates a tedious discussion on a difficult point, namely, whether the transmission of a

character, which is at first inherited by both sexes can be subsequently limited in its transmission to one sex

alone by means of natural selection. We must bear in mind, as shewn in the preliminary chapter on sexual

selection, that characters which are limited in their development to one sex are always latent in the other. An

imaginary illustration will best aid us in seeing the difficulty of the case; we may suppose that a fancier

wished to make a breed of pigeons, in which the males alone should be coloured of a pale blue, whilst the

females retained their former slaty tint. As with pigeons characters of all kinds are usually transmitted to both

sexes equally, the fancier would have to try to convert this latter form of inheritance into sexuallylimited

transmission. All that he could do would be to persevere in selecting every male pigeon which was in the

least degree of a paler blue; and the natural result of this process, if steadily carried on for a long time, and if

the pale variations were strongly inherited or often recurred, would be to make his whole stock of a lighter

blue. But our fancier would be compelled to match, generation after generation, his pale blue males with slaty

females, for he wishes to keep the latter of this colour. The result would generally be the production either of

a mongrel piebald lot, or more probably the speedy and complete loss of the paleblue tint; for the primordial

slaty colour would be transmitted with prepotent force. Supposing, however, that some paleblue males and

slaty females were produced during each successive generation, and were always crossed together, then the

slaty females would have, if I may use the expression, much blue blood in their veins, for their fathers,

grandfathers, etc., will all have been blue birds. Under these circumstances it is conceivable (though I know

of no distinct facts rendering it probable) that the slaty females might acquire so strong a latent tendency to

paleblueness, that they would not destroy this colour in their male offspring, their female offspring still

inheriting the slaty tint. If so, the desired end of making a breed with the two sexes permanently different in

The extreme importance, or rather necessity in the above case of the desired character, namely,

paleblueness, being present though in a latent state in the female, so that the male offspring should not be

deteriorated, will be best appreciated as follows: the male of Soemmerring's pheasant has a tail thirtyseven

inches in length, whilst that of the female is only eight inches; the tail of the male common pheasant is about

twenty inches, and that of the female twelve inches long. Now if the female Soemmerring pheasant with her

SHORT tail were crossed with the male common pheasant, there can be no doubt that the male hybrid

offspring would have a much LONGER tail than that of the pure offspring of the common pheasant. On the

other hand, if the female common pheasant, with a tail much longer than that of the female Soemmerring

pheasant, were crossed with the male of the latter, the male hybrid offspring would have a much SHORTER

tail than that of the pure offspring of Soemmerring's pheasant. (3. Temminck says that the tail of the female

Phasianus Soemmerringii is only six inches long, 'Planches coloriees,' vol. v. 1838, pp. 487 and 488: the

measurements above given were made for me by Mr. Sclater. For the common pheasant, see Macgillivray,

Our fancier, in order to make his new breed with the males of a paleblue tint, and the females unchanged,

would have to continue selecting the males during many generations; and each stage of paleness would have

to be fixed in the males, and rendered latent in the females. The task would be an extremely difficult one, and

has never been tried, but might possibly be successfully carried out. The chief obstacle would be the early

and complete loss of the paleblue tint, from the necessity of reiterated crosses with the slaty female, the

On the other hand, if one or two males were to vary ever so slightly in paleness, and the variations were from

the first limited in their transmission to the male sex, the task of making a new breed of the desired kind

would be easy, for such males would simply have to be selected and matched with ordinary females. An

analogous case has actually occurred, for there are breeds of the pigeon in Belgium (4. Dr. Chapuis, 'Le

Pigeon Voyageur Belge,' 1865, p. 87.) in which the males alone are marked with black striae. So again Mr.

Tegetmeier has recently shewn (5. The 'Field,' Sept. 1872.) that dragons not rarely produce silvercoloured

birds, which are almost always hens; and he himself has bred ten such females. It is on the other hand a very

unusual event when a silver male is produced; so that nothing would be easier, if desired, than to make a

breed of dragons with blue males and silver females. This tendency is indeed so strong that when Mr.

Tegetmeier at last got a silver male and matched him with one of the silver females, he expected to get a

breed with both sexes thus coloured; he was however disappointed, for the young male reverted to the blue

colour of his grandfather, the young female alone being silver. No doubt with patience this tendency to

reversion in the males, reared from an occasional silver male matched with a silver hen, might be eliminated,

and then both sexes would be coloured alike; and this very process has been followed with success by Mr.

With fowls, variations of colour, limited in their transmission to the male sex, habitually occur. When this

form of inheritance prevails, it might well happen that some of the successive variations would be transferred

to the female, who would then slightly resemble the male, as actually occurs in some breeds. Or again, the

greater number, but not all, of the successive steps might be transferred to both sexes, and the female would

then closely resemble the male. There can hardly be a doubt that this is the cause of the male pouter pigeon

having a somewhat larger crop, and of the male carrier pigeon having somewhat larger wattles, than their

respective females; for fanciers have not selected one sex more than the other, and have had no wish that

these characters should be more strongly displayed in the male than in the female, yet this is the case with

The same process would have to be followed, and the same difficulties encountered, if it were desired to

Lastly, our fancier might wish to make a breed with the two sexes differing from each other, and both from

the parent species. Here the difficulty would be extreme, unless the successive variations were from the first

sexually limited on both sides, and then there would be no difficulty. We see this with the fowl; thus the two

sexes of the pencilled Hamburghs differ greatly from each other, and from the two sexes of the aboriginal

Gallus bankiva; and both are now kept constant to their standard of excellence by continued selection, which

would be impossible unless the distinctive characters of both were limited in their transmission.

The Spanish fowl offers a more curious case; the male has an immense comb, but some of the successive

variations, by the accumulation of which it was acquired, appear to have been transferred to the female; for

she has a comb many times larger than that of the females of the parent species. But the comb of the female

differs in one respect from that of the male, for it is apt to lop over; and within a recent period it has been

ordered by the fancy that this should always be the case, and success has quickly followed the order. Now the

lopping of the comb must be sexually limited in its transmission, otherwise it would prevent the comb of the

male from being perfectly upright, which would be abhorrent to every fancier. On the other hand, the

uprightness of the comb in the male must likewise be a sexually limited character, otherwise it would

From the foregoing illustrations, we see that even with almost unlimited time at command, it would be an

extremely difficult and complex, perhaps an impossible process, to change one form of transmission into the

other through selection. Therefore, without distinct evidence in each case, I am unwilling to admit that this

has been effected in natural species. On the other hand, by means of successive variations, which were from

the first sexually limited in their transmission, there would not be the least difficulty in rendering a male bird

widely different in colour or in any other character from the female; the latter being left unaltered, or slightly

As bright colours are of service to the males in their rivalry with other males, such colours would be selected

whether or not they were transmitted exclusively to the same sex. Consequently the females might be

expected often to partake of the brightness of the males to a greater or less degree; and this occurs with a host

of species. If all the successive variations were transmitted equally to both sexes, the females would be

indistinguishable from the males; and this likewise occurs with many birds. If, however, dull colours were of

high importance for the safety of the female during incubation, as with many ground birds, the females which

varied in brightness, or which received through inheritance from the males any marked accession of

brightness, would sooner or later be destroyed. But the tendency in the males to continue for an indefinite

period transmitting to their female offspring their own brightness, would have to be eliminated by a change in

the form of inheritance; and this, as shewn by our previous illustration, would be extremely difficult. The

more probable result of the longcontinued destruction of the more brightlycoloured females, supposing the

equal form of transmission to prevail, would be the lessening or annihilation of the bright colours of the

males, owing to their continual crossing with the duller females. It would be tedious to follow out all the

other possible results; but I may remind the reader that if sexuallylimited variations in brightness occurred

in the females, even if they were not in the least injurious to them and consequently were not eliminated, yet

they would not be favoured or selected, for the male usually accepts any female, and does not select the more

attractive individuals; consequently these variations would be liable to be lost, and would have little influence

on the character of the race; and this will aid in accounting for the females being commonly dullercoloured

In the eighth chapter instances were given, to which many might here be added, of variations occurring at

various ages, and inherited at the corresponding age. It was also shewn that variations which occur late in life

are commonly transmitted to the same sex in which they first appear; whilst variations occurring early in life

are apt to be transmitted to both sexes; not that all the cases of sexuallylimited transmission can thus be

accounted for. It was further shewn that if a male bird varied by becoming brighter whilst young, such

variations would be of no service until the age for reproduction had arrived, and there was competition

between rival males. But in the case of birds living on the ground and commonly in need of the protection of

dull colours, bright tints would be far more dangerous to the young and inexperienced than to the adult males.

Consequently the males which varied in brightness whilst young would suffer much destruction and be

eliminated through natural selection; on the other hand, the males which varied in this manner when nearly

mature, notwithstanding that they were exposed to some additional danger, might survive, and from being

favoured through sexual selection, would procreate their kind. As a relation often exists between the period of

variation and the form of transmission, if the brightcoloured young males were destroyed and the mature

ones were successful in their courtship, the males alone would acquire brilliant colours and would transmit

them exclusively to their male offspring. But I by no means wish to maintain that the influence of age on the

form of transmission, is the sole cause of the great difference in brilliancy between the sexes of many birds.

When the sexes of birds differ in colour, it is interesting to determine whether the males alone have been

modified by sexual selection, the females having been left unchanged, or only partially and indirectly thus

changed; or whether the females have been specially modified through natural selection for the sake of

protection. I will therefore discuss this question at some length, even more fully than its intrinsic importance

deserves; for various curious collateral points may thus be conveniently considered.

Before we enter on the subject of colour, more especially in reference to Mr. Wallace's conclusions, it may be

useful to discuss some other sexual differences under a similar point of view. A breed of fowls formerly

existed in Germany (6. Bechstein, 'Naturgeschichte Deutschlands,' 1793, B. iii. 339.) in which the hens were

furnished with spurs; they were good layers, but they so greatly disturbed their nests with their spurs that they

could not be allowed to sit on their own eggs. Hence at one time it appeared to me probable that with the

females of the wild Gallinaceae the development of spurs had been checked through natural selection, from

the injury thus caused to their nests. This seemed all the more probable, as wingspurs, which would not be

injurious during incubation, are often as welldeveloped in the female as in the male; though in not a few

cases they are rather larger in the male. When the male is furnished with legspurs the female almost always

exhibits rudiments of them,the rudiment sometimes consisting of a mere scale, as in Gallus. Hence it might

be argued that the females had aboriginally been furnished with welldeveloped spurs, but that these had

subsequently been lost through disuse or natural selection. But if this view be admitted, it would have to be

extended to innumerable other cases; and it implies that the female progenitors of the existing spurbearing

In some few genera and species, as in Galloperdix, Acomus, and the Javan peacock (Pavo muticus), the

females, as well as the males, possess well developed legspurs. Are we to infer from this fact that they

construct a different sort of nest from that made by their nearest allies, and not liable to be injured by their

spurs; so that the spurs have not been removed? Or are we to suppose that the females of these several species

especially require spurs for their defence? It is a more probable conclusion that both the presence and absence

of spurs in the females result from different laws of inheritance having prevailed, independently of natural

selection. With the many females in which spurs appear as rudiments, we may conclude that some few of the

successive variations, through which they were developed in the males, occurred very early in life, and were

consequently transferred to the females. In the other and much rarer cases, in which the females possess fully

developed spurs, we may conclude that all the successive variations were transferred to them; and that they

The vocal organs and the feathers variously modified for producing sound, as well as the proper instincts for

using them, often differ in the two sexes, but are sometimes the same in both. Can such differences be

accounted for by the males having acquired these organs and instincts, whilst the females have been saved

from inheriting them, on account of the danger to which they would have been exposed by attracting the

attention of birds or beasts of prey? This does not seem to me probable, when we think of the multitude of

birds which with impunity gladden the country with their voices during the spring. (7. Daines Barrington,

however, thought it probable ('Philosophical Transactions,' 1773, p. 164) that few female birds sing, because

the talent would have been dangerous to them during incubation. He adds, that a similar view may possibly

account for the inferiority of the female to the male in plumage.) It is a safer conclusion that, as vocal and

instrumental organs are of special service only to the males during their courtship, these organs were

developed through sexual selection and their constant use in that sex alonethe successive variations and the

effects of use having been from the first more or less limited in transmission to the male offspring.

Many analogous cases could be adduced; those for instance of the plumes on the head being generally longer

in the male than in the female, sometimes of equal length in both sexes, and occasionally absent in the

female, these several cases occurring in the same group of birds. It would be difficult to account for such a

difference between the sexes by the female having been benefited by possessing a slightly shorter crest than

the male, and its consequent diminution or complete suppression through natural selection. But I will take a

more favourable case, namely the length of the tail. The long train of the peacock would have been not only

inconvenient but dangerous to the peahen during the period of incubation and whilst accompanying her

young. Hence there is not the least a priori improbability in the development of her tail having been checked

through natural selection. But the females of various pheasants, which apparently are exposed on their open

nests to as much danger as the peahen, have tails of considerable length. The females as well as the males of

the Menura superba have long tails, and they build a domed nest, which is a great anomaly in so large a bird.

Naturalists have wondered how the female Menura could manage her tail during incubation; but it is now

known (8. Mr. Ramsay, in 'Proc. Zoolog. Soc.' 1868, p. 50.) that she "enters the nest head first, and then turns

round with her tail sometimes over her back, but more often bent round by her side. Thus in time the tail

becomes quite askew, and is a tolerable guide to the length of time the bird has been sitting." Both sexes of an

Australian kingfisher (Tanysiptera sylvia) have the middle tailfeathers greatly lengthened, and the female

makes her nest in a hole; and as I am informed by Mr. R.B. Sharpe these feathers become much crumpled

In these two latter cases the great length of the tailfeathers must be in some degree inconvenient to the

female; and as in both species the tail feathers of the female are somewhat shorter than those of the male, it

might be argued that their full development had been prevented through natural selection. But if the

development of the tail of the peahen had been checked only when it became inconveniently or dangerously

great, she would have retained a much longer tail than she actually possesses; for her tail is not nearly so

long, relatively to the size of her body, as that of many female pheasants, nor longer than that of the female

turkey. It must also be borne in mind that, in accordance with this view, as soon as the tail of the peahen

became dangerously long, and its development was consequently checked, she would have continually

reacted on her male progeny, and thus have prevented the peacock from acquiring his present magnificent

train. We may therefore infer that the length of the tail in the peacock and its shortness in the peahen are the

result of the requisite variations in the male having been from the first transmitted to the male offspring alone.

We are led to a nearly similar conclusion with respect to the length of the tail in the various species of

pheasants. In the Eared pheasant (Crossoptilon auritum) the tail is of equal length in both sexes, namely

sixteen or seventeen inches; in the common pheasant it is about twenty inches long in the male and twelve in

the female; in Soemmerring's pheasant, thirtyseven inches in the male and only eight in the female; and

lastly in Reeve's pheasant it is sometimes actually seventytwo inches long in the male and sixteen in the

female. Thus in the several species, the tail of the female differs much in length, irrespectively of that of the

male; and this can be accounted for, as it seems to me, with much more probability, by the laws of

inheritance,that is by the successive variations having been from the first more or less closely limited in

their transmission to the male sex than by the agency of natural selection, resulting from the length of tail

We may now consider Mr. Wallace's arguments in regard to the sexual coloration of birds. He believes that

the bright tints originally acquired through sexual selection by the males would in all, or almost all cases,

have been transmitted to the females, unless the transference had been checked through natural selection. I

may here remind the reader that various facts opposed to this view have already been given under reptiles,

amphibians, fishes and lepidoptera. Mr. Wallace rests his belief chiefly, but not exclusively, as we shall see in

the next chapter, on the following statement (9. 'Journal of Travel,' edited by A. Murray, vol. i. 1868, p. 78.),

that when both sexes are coloured in a very conspicuous manner, the nest is of such a nature as to conceal the

sitting bird; but when there is a marked contrast of colour between the sexes, the male being gay and the

female dullcoloured, the nest is open and exposes the sitting bird to view. This coincidence, as far as it goes,

certainly seems to favour the belief that the females which sit on open nests have been specially modified for

the sake of protection; but we shall presently see that there is another and more probable explanation, namely,

that conspicuous females have acquired the instinct of building domed nests oftener than dull coloured

birds. Mr. Wallace admits that there are, as might have been expected, some exceptions to his two rules, but it

is a question whether the exceptions are not so numerous as seriously to invalidate them.

There is in the first place much truth in the Duke of Argyll's remark (10. 'Journal of Travel,' edited by A.

Murray, vol. i. 1868, p. 281.) that a large domed nest is more conspicuous to an enemy, especially to all tree

haunting carnivorous animals, than a smaller open nest. Nor must we forget that with many birds which build

open nests, the male sits on the eggs and aids the female in feeding the young: this is the case, for instance,

with Pyranga aestiva (11. Audubon, 'Ornithological Biography,' vol. i. p. 233.), one of the most splendid

birds in the United States, the male being vermilion, and the female light brownishgreen. Now if brilliant

colours had been extremely dangerous to birds whilst sitting on their open nests, the males in these cases

would have suffered greatly. It might, however, be of such paramount importance to the male to be brilliantly

coloured, in order to beat his rivals, that this may have more than compensated some additional danger.

Mr. Wallace admits that with the Kingcrows (Dicrurus), Orioles, and Pittidae, the females are conspicuously

coloured, yet build open nests; but he urges that the birds of the first group are highly pugnacious and could

defend themselves; that those of the second group take extreme care in concealing their open nests, but this

does not invariably hold good (12. Jerdon, 'Birds of India,' vol. ii. p. 108. Gould's 'Handbook of the Birds of

Australia,' vol. i. p. 463.); and that with the birds of the third group the females are brightly coloured chiefly

on the under surface. Besides these cases, pigeons which are sometimes brightly, and almost always

conspicuously coloured, and which are notoriously liable to the attacks of birds of prey, offer a serious

exception to the rule, for they almost always build open and exposed nests. In another large family, that of the

hummingbirds, all the species build open nests, yet with some of the most gorgeous species the sexes are

alike; and in the majority, the females, though less brilliant than the males, are brightly coloured. Nor can it

be maintained that all female hummingbirds, which are brightly coloured, escape detection by their tints

being green, for some display on their upper surfaces red, blue, and other colours. (13. For instance, the

female Eupetomena macroura has the head and tail dark blue with reddish loins; the female Lampornis

porphyrurus is blackishgreen on the upper surface, with the lores and sides of the throat crimson; the female

Eulampis jugularis has the top of the head and back green, but the loins and the tail are crimson. Many other

instances of highly conspicuous females could be given. See Mr. Gould's magnificent work on this family.)

In regard to birds which build in holes or construct domed nests, other advantages, as Mr. Wallace remarks,

besides concealment are gained, such as shelter from the rain, greater warmth, and in hot countries protection

from the sun (14. Mr. Salvin noticed in Guatemala ('Ibis,' 1864, p. 375) that hummingbirds were much more

unwilling to leave their nests during very hot weather, when the sun was shining brightly, as if their eggs

would be thus injured, than during cool, cloudy, or rainy weather.); so that it is no valid objection to his view

that many birds having both sexes obscurely coloured build concealed nests. (15. I may specify, as instances

of dull coloured birds building concealed nests, the species belonging to eight Australian genera described

in Gould's 'Handbook of the Birds of Australia,' vol. i. pp. 340, 362, 365, 383, 387, 389, 391, 414.) The

female Hornbill (Buceros), for instance, of India and Africa is protected during incubation with

extraordinary care, for she plasters up with her own excrement the orifice of the hole in which she sits on her

eggs, leaving only a small orifice through which the male feeds her; she is thus kept a close prisoner during

the whole period of incubation (16. Mr. C. Horne, 'Proc. Zoolog. Soc.' 1869. p. 243.); yet female hornbills

are not more conspicuously coloured than many other birds of equal size which build open nests. It is a more

serious objection to Mr. Wallace's view, as is admitted by him, that in some few groups the males are

brilliantly coloured and the females obscure, and yet the latter hatch their eggs in domed nests. This is the

case with the Grallinae of Australia, the Superb Warblers (Maluridae) of the same country, the Sunbirds

(Nectariniae), and with several of the Australian Honeysuckers or Meliphagidae. (17. On the nidification

and colours of these latter species, see Gould's 'Handbook to the Birds of Australia,' vol. i. pp. 504, 527.)

If we look to the birds of England we shall see that there is no close and general relation between the colours

of the female and the nature of the nest which is constructed. About forty of our British birds (excluding

those of large size which could defend themselves) build in holes in banks, rocks, or trees, or construct

domed nests. If we take the colours of the female goldfinch, bullfinch, or blackbird, as a standard of the

degree of conspicuousness, which is not highly dangerous to the sitting female, then out of the above forty

birds the females of only twelve can be considered as conspicuous to a dangerous degree, the remaining

twentyeight being inconspicuous. (18. I have consulted, on this subject, Macgillivray's 'British Birds,' and

though doubts may be entertained in some cases in regard to the degree of concealment of the nest, and to the

degree of conspicuousness of the female, yet the following birds, which all lay their eggs in holes or in

domed nests, can hardly be considered, by the above standard, as conspicuous: Passer, 2 species; Sturnus, of

which the female is considerably less brilliant than the male; Cinclus; Motallica boarula (?); Erithacus (?);

Fruticola, 2 sp.; Saxicola; Ruticilla, 2 sp.; Sylvia, 3 sp.; Parus, 3 sp.; Mecistura; Anorthura; Certhia; Sitta;

Yunx; Muscicapa, 2 sp.; Hirundo, 3 sp.; and Cypselus. The females of the following 12 birds may be

considered as conspicuous according to the same standard, viz., Pastor, Motacilla alba, Parus major and P.

caeruleus, Upupa, Picus, 4 sp., Coracias, Alcedo, and Merops.) Nor is there any close relation within the

same genus between a wellpronounced difference in colour between the sexes, and the nature of the nest

constructed. Thus the male house sparrow (Passer domesticus) differs much from the female, the male

treesparrow (P. montanus) hardly at all, and yet both build wellconcealed nests. The two sexes of the

common flycatcher (Muscicapa grisola) can hardly be distinguished, whilst the sexes of the pied flycatcher

(M. luctuosa) differ considerably, and both species build in holes or conceal their nests. The female blackbird

(Turdus merula) differs much, the female ring ouzel (T. torquatus) differs less, and the female common

thrush (T. musicus) hardly at all from their respective males; yet all build open nests. On the other hand, the

not very distantlyallied waterouzel (Cinclus aquaticus) builds a domed nest, and the sexes differ about as

much as in the ringouzel. The black and red grouse (Tetrao tetrix and T. scoticus) build open nests in

equally wellconcealed spots, but in the one species the sexes differ greatly, and in the other very little.

Notwithstanding the foregoing objections, I cannot doubt, after reading Mr. Wallace's excellent essay, that

looking to the birds of the world, a large majority of the species in which the females are conspicuously

coloured (and in this case the males with rare exceptions are equally conspicuous), build concealed nests for

the sake of protection. Mr. Wallace enumerates (19. 'Journal of Travel,' edited by A. Murray, vol. i. p. 78.) a

long series of groups in which this rule holds good; but it will suffice here to give, as instances, the more

familiar groups of kingfishers, toucans, trogons, puffbirds (Capitonidae), plantaineaters (Musophagae,

woodpeckers, and parrots. Mr. Wallace believes that in these groups, as the males gradually acquired through

sexual selection their brilliant colours, these were transferred to the females and were not eliminated by

natural selection, owing to the protection which they already enjoyed from their manner of nidification.

According to this view, their present manner of nesting was acquired before their present colours. But it

seems to me much more probable that in most cases, as the females were gradually rendered more and more

brilliant from partaking of the colours of the male, they were gradually led to change their instincts

(supposing that they originally built open nests), and to seek protection by building domed or concealed

nests. No one who studies, for instance, Audubon's account of the differences in the nests of the same species

in the Northern and Southern United States (20. See many statements in the 'Ornithological Biography.' See

also some curious observations on the nests of Italian birds by Eugenio Bettoni, in the 'Atti della Societa

Italiana,' vol. xi. 1869, p. 487.), will feel any great difficulty in admitting that birds, either by a change (in the

strict sense of the word) of their habits, or through the natural selection of socalled spontaneous variations

This way of viewing the relation, as far as it holds good, between the bright colours of female birds and their

manner of nesting, receives some support from certain cases occurring in the Sahara Desert. Here, as in most

other deserts, various birds, and many other animals, have had their colours adapted in a wonderful manner to

the tints of the surrounding surface. Nevertheless there are, as I am informed by the Rev. Mr. Tristram, some

curious exceptions to the rule; thus the male of the Monticola cyanea is conspicuous from his bright blue

colour, and the female almost equally conspicuous from her mottled brown and white plumage; both sexes of

two species of Dromolaea are of a lustrous black; so that these three species are far from receiving protection

from their colours, yet they are able to survive, for they have acquired the habit of taking refuge from danger

With respect to the above groups in which the females are conspicuously coloured and build concealed nests,

it is not necessary to suppose that each separate species had its nidifying instinct specially modified; but only

that the early progenitors of each group were gradually led to build domed or concealed nests, and afterwards

transmitted this instinct, together with their bright colours, to their modified descendants. As far as it can be

trusted, the conclusion is interesting, that sexual selection together with equal or nearly equal inheritance by

both sexes, have indirectly determined the manner of nidification of whole groups of birds.

According to Mr. Wallace, even in the groups in which the females, from being protected in domed nests

during incubation, have not had their bright colours eliminated through natural selection, the males often

differ in a slight, and occasionally in a considerable degree from the females. This is a significant fact, for

such differences in colour must be accounted for by some of the variations in the males having been from the

first limited in transmission to the same sex; as it can hardly be maintained that these differences, especially

when very slight, serve as a protection to the female. Thus all the species in the splendid group of the

Trogons build in holes; and Mr. Gould gives figures (21. See his Monograph of the Trogonidae, 1st edition.)

of both sexes of twentyfive species, in all of which, with one partial exception, the sexes differ sometimes

slightly, sometimes conspicuously, in colour,the males being always finer than the females, though the

latter are likewise beautiful. All the species of kingfishers build in holes, and with most of the species the

sexes are equally brilliant, and thus far Mr. Wallace's rule holds good; but in some of the Australian species

the colours of the females are rather less vivid than those of the male; and in one splendidlycoloured

species, the sexes differ so much that they were at first thought to be specifically distinct. (22. Namely,

Cyanalcyon, Gould's 'Handbook to the Birds of Australia,' vol. i. p. 133; see, also, pp. 130, 136.) Mr. R.B.

Sharpe, who has especially studied this group, has shewn me some American species (Ceryle) in which the

breast of the male is belted with black. Again, in Carcineutes, the difference between the sexes is

conspicuous: in the male the upper surface is dullblue banded with black, the lower surface being partly

fawncoloured, and there is much red about the head; in the female the upper surface is reddishbrown

banded with black, and the lower surface white with black markings. It is an interesting fact, as shewing how

the same peculiar style of sexual colouring often characterises allied forms, that in three species of Dacelo the

male differs from the female only in the tail being dullblue banded with black, whilst that of the female is

brown with blackish bars; so that here the tail differs in colour in the two sexes in exactly the same manner as

With parrots, which likewise build in holes, we find analogous cases: in most of the species, both sexes are

brilliantly coloured and indistinguishable, but in not a few species the males are coloured rather more vividly

than the females, or even very differently from them. Thus, besides other stronglymarked differences, the

whole under surface of the male King Lory (Aprosmictus scapulatus) is scarlet, whilst the throat and chest of

the female is green tinged with red: in the Euphema splendida there is a similar difference, the face and wing

coverts moreover of the female being of a paler blue than in the male. (23. Every gradation of difference

between the sexes may be followed in the parrots of Australia. See Gould's 'Handbook,' etc., vol. ii. pp.

14102.) In the family of the tits (Parinae), which build concealed nests, the female of our common blue

tomtit (Parus caeruleus), is "much less brightly coloured" than the male: and in the magnificent Sultan yellow

tit of India the difference is greater. (24. Macgillivray's 'British Birds,' vol. ii. p. 433. Jerdon, 'Birds of India,'

Again, in the great group of the woodpeckers (25. All the following facts are taken from M. Malherbe's

magnificent 'Monographie des Picidees,' 1861.), the sexes are generally nearly alike, but in the Megapicus

validus all those parts of the head, neck, and breast, which are crimson in the male are pale brown in the

female. As in several woodpeckers the head of the male is bright crimson, whilst that of the female is plain, it

occurred to me that this colour might possibly make the female dangerously conspicuous, whenever she put

her head out of the hole containing her nest, and consequently that this colour, in accordance with Mr.

Wallace's belief, had been eliminated. This view is strengthened by what Malherbe states with respect to

Indopicus carlotta; namely, that the young females, like the young males, have some crimson about their

heads, but that this colour disappears in the adult female, whilst it is intensified in the adult male.

Nevertheless the following considerations render this view extremely doubtful: the male takes a fair share in

incubation (26. Audubon's 'Ornithological Biography,' vol. ii. p. 75; see also the 'Ibis,' vol. i. p. 268.), and

would be thus almost equally exposed to danger; both sexes of many species have their heads of an equally

bright crimson; in other species the difference between the sexes in the amount of scarlet is so slight that it

can hardly make any appreciable difference in the danger incurred; and lastly, the colouring of the head in the

The cases, as yet given, of slight and graduated differences in colour between the males and females in the

groups, in which as a general rule the sexes resemble each other, all relate to species which build domed or

concealed nests. But similar gradations may likewise be observed in groups in which the sexes as a general

As I have before instanced the Australian parrots, so I may here instance, without giving any details, the

Australian pigeons. (27. Gould's 'Handbook to the Birds of Australia,' vol. ii. pp. 109149.) It deserves

especial notice that in all these cases the slight differences in plumage between the sexes are of the same

general nature as the occasionally greater differences. A good illustration of this fact has already been

afforded by those kingfishers in which either the tail alone or the whole upper surface of the plumage differs

in the same manner in the two sexes. Similar cases may be observed with parrots and pigeons. The

differences in colour between the sexes of the same species are, also, of the same general nature as the

differences in colour between the distinct species of the same group. For when in a group in which the sexes

are usually alike, the male differs considerably from the female, he is not coloured in a quite new style.

Hence we may infer that within the same group the special colours of both sexes when they are alike, and the

colours of the male, when he differs slightly or even considerably from the female, have been in most cases

It is not probable, as has already been remarked, that differences in colour between the sexes, when very

slight, can be of service to the female as a protection. Assuming, however, that they are of service, they might

be thought to be cases of transition; but we have no reason to believe that many species at any one time are

undergoing change. Therefore we can hardly admit that the numerous females which differ very slightly in

colour from their males are now all commencing to become obscure for the sake of protection. Even if we

consider somewhat more marked sexual differences, is it probable, for instance, that the head of the female

chaffinch,the crimson on the breast of the female bullfinch,the green of the female greenfinch,the

crest of the female goldencrested wren, have all been rendered less bright by the slow process of selection

for the sake of protection? I cannot think so; and still less with the slight differences between the sexes of

those birds which build concealed nests. On the other hand, the differences in colour between the sexes,

whether great or small, may to a large extent be explained on the principle of the successive variations,

acquired by the males through sexual selection, having been from the first more or less limited in their

transmission to the females. That the degree of limitation should differ in different species of the same group

will not surprise any one who has studied the laws of inheritance, for they are so complex that they appear to

us in our ignorance to be capricious in their action. (28. See remarks to this effect in 'Variation of Animals

As far as I can discover there are few large groups of birds in which all the species have both sexes alike and

brilliantly coloured, but I hear from Mr. Sclater, that this appears to be the case with the Musophagae or

plantaineaters. Nor do I believe that any large group exists in which the sexes of all the species are widely

dissimilar in colour: Mr. Wallace informs me that the chatterers of S. America (Cotingidae) offer one of the

best instances; but with some of the species, in which the male has a splendid red breast, the female exhibits

some red on her breast; and the females of other species shew traces of the green and other colours of the

males. Nevertheless we have a near approach to close sexual similarity or dissimilarity throughout several

groups: and this, from what has just been said of the fluctuating nature of inheritance, is a somewhat

surprising circumstance. But that the same laws should largely prevail with allied animals is not surprising.

The domestic fowl has produced a great number of breeds and subbreeds, and in these the sexes generally

differ in plumage; so that it has been noticed as an unusual circumstance when in certain subbreeds they

resemble each other. On the other hand, the domestic pigeon has likewise produced a vast number of distinct

breeds and subbreeds, and in these, with rare exceptions, the two sexes are identically alike.

Therefore if other species of Gallus and Columba were domesticated and varied, it would not be rash to

predict that similar rules of sexual similarity and dissimilarity, depending on the form of transmission, would

hold good in both cases. In like manner the same form of transmission has generally prevailed under nature

throughout the same groups, although marked exceptions to this rule occur. Thus within the same family or

even genus, the sexes may be identically alike, or very different in colour. Instances have already been given

in the same genus, as with sparrows, fly catchers, thrushes and grouse. In the family of pheasants the sexes

of almost all the species are wonderfully dissimilar, but are quite alike in the eared pheasant or Crossoptilon

auritum. In two species of Chloephaga, a genus of geese, the male cannot be distinguished from the females,

except by size; whilst in two others, the sexes are so unlike that they might easily be mistaken for distinct

The laws of inheritance can alone account for the following cases, in which the female acquires, late in life,

certain characters proper to the male, and ultimately comes to resemble him more or less completely. Here

protection can hardly have come into play. Mr. Blyth informs me that the females of Oriolus melanocephalus

and of some allied species, when sufficiently mature to breed, differ considerably in plumage from the adult

males; but after the second or third moults they differ only in their beaks having a slight greenish tinge. In the

dwarf bitterns (Ardetta), according to the same authority, "the male acquires his final livery at the first moult,

the female not before the third or fourth moult; in the meanwhile she presents an intermediate garb, which is

ultimately exchanged for the same livery as that of the male." So again the female Falco peregrinus acquires

her blue plumage more slowly than the male. Mr. Swinhoe states that with one of the Drongo shrikes

(Dicrurus macrocercus) the male, whilst almost a nestling, moults his soft brown plumage and becomes of a

uniform glossy greenishblack; but the female retains for a long time the white striae and spots on the

axillary feathers; and does not completely assume the uniform black colour of the male for three years. The

same excellent observer remarks that in the spring of the second year the female spoon bill (Platalea) of

China resembles the male of the first year, and that apparently it is not until the third spring that she acquires

the same adult plumage as that possessed by the male at a much earlier age. The female Bombycilla

carolinensis differs very little from the male, but the appendages, which like beads of red sealingwax

ornament the wingfeathers (30. When the male courts the female, these ornaments are vibrated, and "are

shewn off to great advantage," on the outstretched wings: A. Leith Adams, 'Field and Forest Rambles,' 1873,

p. 153.), are not developed in her so early in life as in the male. In the male of an Indian parrakeet (Palaeornis

javanicus) the upper mandible is coralred from his earliest youth, but in the female, as Mr. Blyth has

observed with caged and wild birds, it is at first black and does not become red until the bird is at least a year

old, at which age the sexes resemble each other in all respects. Both sexes of the wild turkey are ultimately

furnished with a tuft of bristles on the breast, but in twoyearold birds the tuft is about four inches long in

the male and hardly apparent in the female; when, however, the latter has reached her fourth year, it is from

four to five inches in length. (31. On Ardetta, Translation of Cuvier's 'Regne Animal,' by Mr. Blyth, footnote,

p. 159. On the Peregrine Falcon, Mr. Blyth, in Charlesworth's 'Mag. of Nat. Hist.' vol. i. 1837, p. 304. On

Dicrurus, 'Ibis,' 1863, p. 44. On the Platalea, 'Ibis,' vol. vi. 1864, p. 366. On the Bombycilla, Audubon's

'Ornitholog. Biography,' vol. i. p. 229. On the Palaeornis, see, also, Jerdon, 'Birds of India,' vol. i. p. 263. On

the wild turkey, Audubon, ibid. vol. i. p. 15; but I hear from Judge Caton that in Illinois the female very

rarely acquires a tuft. Analogous cases with the females of Petrocossyphus are given by Mr. R. Sharpe,

These cases must not be confounded with those where diseased or old females abnormally assume masculine

characters, nor with those where fertile females, whilst young, acquire the characters of the male, through

variation or some unknown cause. (32. Of these latter cases Mr. Blyth has recorded (Translation of Cuvier's

'Regne Animal,' p. 158) various instances with Lanius, Ruticilla, Linaria, and Anas. Audubon has also

recorded a similar case ('Ornitholog. Biography,' vol. v. p. 519) with Pyranga aestiva.) But all these cases

have so much in common that they depend, according to the hypothesis of pangenesis, on gemmules derived

from each part of the male being present, though latent, in the female; their development following on some

A few words must be added on changes of plumage in relation to the season of the year. From reasons

formerly assigned there can be little doubt that the elegant plumes, long pendant feathers, crests, etc., of

egrets, herons, and many other birds, which are developed and retained only during the summer, serve for

ornamental and nuptial purposes, though common to both sexes. The female is thus rendered more

conspicuous during the period of incubation than during the winter; but such birds as herons and egrets would

be able to defend themselves. As, however, plumes would probably be inconvenient and certainly of no use

during the winter, it is possible that the habit of moulting twice in the year may have been gradually acquired

through natural selection for the sake of casting off inconvenient ornaments during the winter. But this view

cannot be extended to the many waders, whose summer and winter plumages differ very little in colour. With

defenceless species, in which both sexes, or the males alone, become extremely conspicuous during the

breedingseason,or when the males acquire at this season such long wing or tailfeathers as to impede

their flight, as with Cosmetornis and Vidua,it certainly at first appears highly probable that the second

moult has been gained for the special purpose of throwing off these ornaments. We must, however, remember

that many birds, such as some of the Birds of Paradise, the Argus pheasant and peacock, do not cast their

plumes during the winter; and it can hardly be maintained that the constitution of these birds, at least of the

Gallinaceae, renders a double moult impossible, for the ptarmigan moults thrice in the year. (33. See Gould's

'Birds of Great Britain.') Hence it must be considered as doubtful whether the many species which moult their

ornamental plumes or lose their bright colours during the winter, have acquired this habit on account of the

I conclude, therefore, that the habit of moulting twice in the year was in most or all cases first acquired for

some distinct purpose, perhaps for gaining a warmer winter covering; and that variations in the plumage

occurring during the summer were accumulated through sexual selection, and transmitted to the offspring at

the same season of the year; that such variations were inherited either by both sexes or by the males alone,

according to the form of inheritance which prevailed. This appears more probable than that the species in all

cases originally tended to retain their ornamental plumage during the winter, but were saved from this

through natural selection, resulting from the inconvenience or danger thus caused.

I have endeavoured in this chapter to shew that the arguments are not trustworthy in favour of the view that

weapons, bright colours, and various ornaments, are now confined to the males owing to the conversion, by

natural selection, of the equal transmission of characters to both sexes, into transmission to the male sex

alone. It is also doubtful whether the colours of many female birds are due to the preservation, for the sake of

protection, of variations which were from the first limited in their transmission to the female sex. But it will

be convenient to defer any further discussion on this subject until I treat, in the following chapter, of the

The immature plumage in relation to the character of the plumage in both sexes when adultSix classes of

casesSexual differences between the males of closelyallied or representative speciesThe female

assuming the characters of the malePlumage of the young in relation to the summer and winter plumage of

the adultsOn the increase of beauty in the birds of the worldProtective colouringConspicuously

We must now consider the transmission of characters, as limited by age, in reference to sexual selection. The

truth and importance of the principle of inheritance at corresponding ages need not here be discussed, as

enough has already been said on the subject. Before giving the several rather complex rules or classes of

cases, under which the differences in plumage between the young and the old, as far as known to me, may be

With animals of all kinds when the adults differ in colour from the young, and the colours of the latter are

not, as far as we can see, of any special service, they may generally be attributed, like various embryological

structures, to the retention of a former character. But this view can be maintained with confidence, only when

the young of several species resemble each other closely, and likewise resemble other adult species belonging

to the same group; for the latter are the living proofs that such a state of things was formerly possible. Young

lions and pumas are marked with feeble stripes or rows of spots, and as many allied species both young and

old are similarly marked, no believer in evolution will doubt that the progenitor of the lion and puma was a

striped animal, and that the young have retained vestiges of the stripes, like the kittens of black cats, which

are not in the least striped when grown up. Many species of deer, which when mature are not spotted, are

whilst young covered with white spots, as are likewise some few species in the adult state. So again the

young in the whole family of pigs (Suidae), and in certain rather distantly allied animals, such as the tapir, are

marked with dark longitudinal stripes; but here we have a character apparently derived from an extinct

progenitor, and now preserved by the young alone. In all such cases the old have had their colours changed in

the course of time, whilst the young have remained but little altered, and this has been effected through the

This same principle applies to many birds belonging to various groups, in which the young closely resemble

each other, and differ much from their respective adult parents. The young of almost all the Gallinaceae, and

of some distantly allied birds such as ostriches, are covered with longitudinally striped down; but this

character points back to a state of things so remote that it hardly concerns us. Young crossbills (Loxia) have

at first straight beaks like those of other finches, and in their immature striated plumage they resemble the

mature redpole and female siskin, as well as the young of the goldfinch, greenfinch, and some other allied

species. The young of many kinds of buntings (Emberiza) resemble one another, and likewise the adult state

of the common bunting, E. miliaria. In almost the whole large group of thrushes the young have their breasts

spotteda character which is retained throughout life by many species, but is quite lost by others, as by the

Turdus migratorius. So again with many thrushes, the feathers on the back are mottled before they are

moulted for the first time, and this character is retained for life by certain eastern species. The young of many

species of shrikes (Lanius), of some woodpeckers, and of an Indian pigeon (Chalcophaps indicus), are

transversely striped on the under surface; and certain allied species or whole genera are similarly marked

when adult. In some closelyallied and resplendent Indian cuckoos (Chrysococcyx), the mature species differ

considerably from one another in colour, but the young cannot be distinguished. The young of an Indian

goose (Sarkidiornis melanonotus) closely resemble in plumage an allied genus, Dendrocygna, when mature.

(1. In regard to thrushes, shrikes, and woodpeckers, see Mr. Blyth, in Charlesworth's 'Mag. of Nat. Hist.' vol.

i. 1837, p. 304; also footnote to his translation of Cuvier's 'Regne Animal,' p. 159. I give the case of Loxia on

Mr. Blyth's information. On thrushes, see also Audubon, 'Ornith. Biog.' vol. ii. p. 195. On Chrysococcyx and

Chalcophaps, Blyth, as quoted in Jerdon's 'Birds of India,' vol. iii. p. 485. On Sarkidiornis, Blyth, in 'Ibis,'

1867, p. 175.) Similar facts will hereafter be given in regard to certain herons. Young blackgrouse (Tetrao

tetrix) resemble the young as well as the old of certain other species, for instance the redgrouse or T.

scoticus. Finally, as Mr. Blyth, who has attended closely to this subject, has well remarked, the natural

affinities of many species are best exhibited in their immature plumage; and as the true affinities of all

organic beings depend on their descent from a common progenitor, this remark strongly confirms the belief

that the immature plumage approximately shews us the former or ancestral condition of the species.

Although many young birds, belonging to various families, thus give us a glimpse of the plumage of their

remote progenitors, yet there are many other birds, both dullcoloured and brightcoloured, in which the

young closely resemble their parents. In such cases the young of the different species cannot resemble each

other more closely than do the parents; nor can they strikingly resemble allied forms when adult. They give

us but little insight into the plumage of their progenitors, excepting in so far that, when the young and the old

are coloured in the same general manner throughout a whole group of species, it is probable that their

We may now consider the classes of cases, under which the differences and resemblances between the

plumage of the young and the old, in both sexes or in one sex alone, may be grouped. Rules of this kind were

first enounced by Cuvier; but with the progress of knowledge they require some modification and

amplification. This I have attempted to do, as far as the extreme complexity of the subject permits, from

information derived from various sources; but a full essay on this subject by some competent ornithologist is

much needed. In order to ascertain to what extent each rule prevails, I have tabulated the facts given in four

great works, namely, by Macgillivray on the birds of Britain, Audubon on those of North America, Jerdon on

those of India, and Gould on those of Australia. I may here premise, first, that the several cases or rules

graduate into each other; and secondly, that when the young are said to resemble their parents, it is not meant

that they are identically alike, for their colours are almost always less vivid, and the feathers are softer and

I. When the adult male is more beautiful or conspicuous than the adult female, the young of both sexes in

their first plumage closely resemble the adult female, as with the common fowl and peacock; or, as

occasionally occurs, they resemble her much more closely than they do the adult male.

II. When the adult female is more conspicuous than the adult male, as sometimes though rarely occurs, the

III. When the adult male resembles the adult female, the young of both sexes have a peculiar first plumage of

IV. When the adult male resembles the adult female, the young of both sexes in their first plumage resemble

V. When the adults of both sexes have a distinct winter and summer plumage, whether or not the male differs

from the female, the young resemble the adults of both sexes in their winter dress, or much more rarely in

their summer dress, or they resemble the females alone. Or the young may have an intermediate character; or

VI. In some few cases the young in their first plumage differ from each other according to sex; the young

males resembling more or less closely the adult males, and the young females more or less closely the adult

In this class, the young of both sexes more or less closely resemble the adult female, whilst the adult male

differs from the adult female, often in the most conspicuous manner. Innumerable instances in all Orders

could be given; it will suffice to call to mind the common pheasant, duck, and housesparrow. The cases

under this class graduate into others. Thus the two sexes when adult may differ so slightly, and the young so

slightly from the adults, that it is doubtful whether such cases ought to come under the present, or under the

third or fourth classes. So again the young of the two sexes, instead of being quite alike, may differ in a slight

degree from each other, as in our sixth class. These transitional cases, however, are few, or at least are not

strongly pronounced, in comparison with those which come strictly under the present class.

The force of the present law is well shewn in those groups, in which, as a general rule, the two sexes and the

young are all alike; for when in these groups the male does differ from the female, as with certain parrots,

kingfishers, pigeons, etc., the young of both sexes resemble the adult female. (2. See, for instance, Mr.

Gould's account ('Handbook to the Birds of Australia,' vol. i. p. 133) of Cyanalcyon (one of the Kingfishers),

in which, however, the young male, though resembling the adult female, is less brilliantly coloured. In some

species of Dacelo the males have blue tails, and the females brown ones; and Mr. R.B. Sharpe informs me

that the tail of the young male of D. gaudichaudi is at first brown. Mr. Gould has described (ibid. vol. ii. pp.

14, 20, 37) the sexes and the young of certain black Cockatoos and of the King Lory, with which the same

rule prevails. Also Jerdon ('Birds of India,' vol. i. p. 260) on the Palaeornis rosa, in which the young are more

like the female than the male. See Audubon ('Ornithological Biography,' vol. ii. p. 475) on the two sexes and

the young of Columba passerina.) We see the same fact exhibited still more clearly in certain anomalous

cases; thus the male of Heliothrix auriculata (one of the hummingbirds) differs conspicuously from the

female in having a splendid gorget and fine eartufts, but the female is remarkable from having a much

longer tail than that of the male; now the young of both sexes resemble (with the exception of the breast

being spotted with bronze) the adult female in all other respects, including the length of her tail, so that the

tail of the male actually becomes shorter as he reaches maturity, which is a most unusual circumstance. (3. I

owe this information to Mr. Gould, who shewed me the specimens; see also his 'Introduction to the

Trochilidae,' 1861, p. 120.) Again, the plumage of the male goosander (Mergus merganser) is more

conspicuously coloured than that of the female, with the scapular and secondary wingfeathers much longer;

but differently from what occurs, as far as I know, in any other bird, the crest of the adult male, though

broader than that of the female, is considerably shorter, being only a little above an inch in length; the crest of

the female being two and a half inches long. Now the young of both sexes entirely resemble the adult female,

so that their crests are actually of greater length, though narrower, than in the adult male. (4. Macgillivray,

When the young and the females closely resemble each other and both differ from the males, the most

obvious conclusion is that the males alone have been modified. Even in the anomalous cases of the Heliothrix

and Mergus, it is probable that originally both adult sexes were furnishedthe one species with a much

elongated tail, and the other with a much elongated crestthese characters having since been partially lost

by the adult males from some unexplained cause, and transmitted in their diminished state to their male

offspring alone, when arrived at the corresponding age of maturity. The belief that in the present class the

male alone has been modified, as far as the differences between the male and the female together with her

young are concerned, is strongly supported by some remarkable facts recorded by Mr. Blyth (5. See his

admirable paper in the 'Journal of the Asiatic Soc. of Bengal,' vol. xix. 1850, p. 223; see also Jerdon, 'Birds of

India,' vol. i. introduction, p. xxix. In regard to Tanysiptera, Prof. Schlegel told Mr. Blyth that he could

distinguish several distinct races, solely by comparing the adult males.), with respect to closelyallied species

which represent each other in distinct countries. For with several of these representative species the adult

males have undergone a certain amount of change and can be distinguished; the females and the young from

the distinct countries being indistinguishable, and therefore absolutely unchanged. This is the case with

certain Indian chats (Thamnobia), with certain honeysuckers (Nectarinia), shrikes (Tephrodornis), certain

kingfishers (Tanysiptera), Kalij pheasants (Gallophasis), and treepartridges (Arboricola).

In some analogous cases, namely with birds having a different summer and winter plumage, but with the two

sexes nearly alike, certain closelyallied species can easily be distinguished in their summer or nuptial

plumage, yet are indistinguishable in their winter as well as in their immature plumage. This is the case with

some of the closelyallied Indian wagtails or Motacillae. Mr. Swinhoe (6. See also Mr. Swinhoe, in 'Ibis,'

July 1863, p. 131; and a previous paper, with an extract from a note by Mr. Blyth, in 'Ibis,' January, 1861, p.

25.) informs me that three species of Ardeola, a genus of herons, which represent one another on separate

continents, are "most strikingly different" when ornamented with their summer plumes, but are hardly, if at

all, distinguishable during the winter. The young also of these three species in their immature plumage

closely resemble the adults in their winter dress. This case is all the more interesting, because with two other

species of Ardeola both sexes retain, during the winter and summer, nearly the same plumage as that

possessed by the three first species during the winter and in their immature state; and this plumage, which is

common to several distinct species at different ages and seasons, probably shews us how the progenitors of

the genus were coloured. In all these cases, the nuptial plumage which we may assume was originally

acquired by the adult males during the breedingseason, and transmitted to the adults of both sexes at the

corresponding season, has been modified, whilst the winter and immature plumages have been left

The question naturally arises, how is it that in these latter cases the winter plumage of both sexes, and in the

former cases the plumage of the adult females, as well as the immature plumage of the young, have not been

at all affected? The species which represent each other in distinct countries will almost always have been

exposed to somewhat different conditions, but we can hardly attribute to this action the modification of the

plumage in the males alone, seeing that the females and the young, though similarly exposed, have not been

affected. Hardly any fact shews us more clearly how subordinate in importance is the direct action of the

conditions of life, in comparison with the accumulation through selection of indefinite variations, than the

surprising difference between the sexes of many birds; for both will have consumed the same food, and have

been exposed to the same climate. Nevertheless we are not precluded from believing that in the course of

time new conditions may produce some direct effect either on both sexes, or from their constitutional

differences chiefly on one sex. We see only that this is subordinate in importance to the accumulated results

of selection. Judging, however, from a widespread analogy, when a species migrates into a new country

(and this must precede the formation of representative species), the changed conditions to which they will

almost always have been exposed will cause them to undergo a certain amount of fluctuating variability. In

this case sexual selection, which depends on an element liable to changethe taste or admiration of the

femalewill have had new shades of colour or other differences to act on and accumulate; and as sexual

selection is always at work, it would (from what we know of the results on domestic animals of man's

unintentional selection), be surprising if animals inhabiting separate districts, which can never cross and thus

blend their newlyacquired characters, were not, after a sufficient lapse of time, differently modified. These

remarks likewise apply to the nuptial or summer plumage, whether confined to the males, or common to both

Although the females of the above closelyallied or representative species, together with their young, differ

hardly at all from one another, so that the males alone can be distinguished, yet the females of most species

within the same genus obviously differ from each other. The differences, however, are rarely as great as

between the males. We see this clearly in the whole family of the Gallinaceae: the females, for instance, of

the common and Japan pheasant, and especially of the gold and Amherst pheasant of the silver pheasant

and the wild fowlresemble one another very closely in colour, whilst the males differ to an extraordinary

degree. So it is with the females of most of the Cotingidae, Fringillidae, and many other families. There can

indeed be no doubt that, as a general rule, the females have been less modified than the males. Some few

birds, however, offer a singular and inexplicable exception; thus the females of Paradisea apoda and P.

papuana differ from each other more than do their respective males (7. Wallace, 'The Malay Archipelago,'

vol. ii. 1869, p. 394.); the female of the latter species having the under surface pure white, whilst the female

P. apoda is deep brown beneath. So, again, as I hear from Professor Newton, the males of two species of

Oxynotus (shrikes), which represent each other in the islands of Mauritius and Bourbon (8. These species are

described with coloured figures, by M. F. Pollen, in 'Ibis,' 1866, p. 275.), differ but little in colour, whilst the

females differ much. In the Bourbon species the female appears to have partially retained an immature

condition of plumage, for at first sight she "might be taken for the young of the Mauritian species." These

differences may be compared with those inexplicable ones, which occur independently of man's selection in

certain subbreeds of the gamefowl, in which the females are very different, whilst the males can hardly be

As I account so largely by sexual selection for the differences between the males of allied species, how can

the differences between the females be accounted for in all ordinary cases? We need not here consider the

species which belong to distinct genera; for with these, adaptation to different habits of life, and other

agencies, will have come into play. In regard to the differences between the females within the same genus, it

appears to me almost certain, after looking through various large groups, that the chief agent has been the

greater or less transference to the female of the characters acquired by the males through sexual selection. In

the several British finches, the two sexes differ either very slightly or considerably; and if we compare the

females of the greenfinch, chaffinch, goldfinch, bullfinch, crossbill, sparrow, etc., we shall see that they differ

from one another chiefly in the points in which they partially resemble their respective males; and the colours

of the males may safely be attributed to sexual selection. With many gallinaceous species the sexes differ to

an extreme degree, as with the peacock, pheasant, and fowl, whilst with other species there has been a partial

or even complete transference of character from the male to the female. The females of the several species of

Polyplectron exhibit in a dim condition, and chiefly on the tail, the splendid ocelli of their males. The female

partridge differs from the male only in the red mark on her breast being smaller; and the female wild turkey

only in her colours being much duller. In the guineafowl the two sexes are indistinguishable. There is no

improbability in the plain, though peculiarly spotted plumage of this latter bird having been acquired through

sexual selection by the males, and then transmitted to both sexes; for it is not essentially different from the

much more beautifully spotted plumage, characteristic of the males alone of the Tragopan pheasants.

It should be observed that, in some instances, the transference of characters from the male to the female has

been effected apparently at a remote period, the male having subsequently undergone great changes, without

transferring to the female any of his latergained characters. For instance, the female and the young of the

blackgrouse (Tetrao tetrix) resemble pretty closely both sexes and the young of the redgrouse (T. scoticus);

and we may consequently infer that the blackgrouse is descended from some ancient species, of which both

sexes were coloured in nearly the same manner as the redgrouse. As both sexes of this latter species are

more distinctly barred during the breedingseason than at any other time, and as the male differs slightly

from the female in his more strongly pronounced red and brown tints (10. Macgillivray, 'History of British

Birds,' vol. i. pp. 172174.), we may conclude that his plumage has been influenced by sexual selection, at

least to a certain extent. If so, we may further infer that nearly similar plumage of the female blackgrouse

was similarly produced at some former period. But since this period the male blackgrouse has acquired his

fine black plumage, with his forked and outwardlycurled tailfeathers; but of these characters there has

hardly been any transference to the female, excepting that she shews in her tail a trace of the curved fork.

We may therefore conclude that the females of distinct though allied species have often had their plumage

rendered more or less different by the transference in various degrees of characters acquired by the males

through sexual selection, both during former and recent times. But it deserves especial attention that brilliant

colours have been transferred much more rarely than other tints. For instance, the male of the redthroated

blue breast (Cyanecula suecica) has a rich blue breast, including a sub triangular red mark; now marks of

nearly the same shape have been transferred to the female, but the central space is fulvous instead of red, and

is surrounded by mottled instead of blue feathers. The Gallinaceae offer many analogous cases; for none of

the species, such as partridges, quails, guineafowls, etc., in which the colours of the plumage have been

largely transferred from the male to the female, are brilliantly coloured. This is well exemplified with the

pheasants, in which the male is generally so much more brilliant than the female; but with the Eared and

Cheer pheasants (Crossoptilon auritum and Phasianus wallichii) the sexes closely resemble each other and

their colours are dull. We may go so far as to believe that if any part of the plumage in the males of these two

pheasants had been brilliantly coloured, it would not have been transferred to the females. These facts

strongly support Mr. Wallace's view that with birds which are exposed to much danger during incubation, the

transference of bright colours from the male to the female has been checked through natural selection. We

must not, however, forget that another explanation, before given, is possible; namely, that the males which

varied and became bright, whilst they were young and inexperienced, would have been exposed to much

danger, and would generally have been destroyed; the older and more cautious males, on the other hand, if

they varied in a like manner, would not only have been able to survive, but would have been favoured in their

rivalry with other males. Now variations occurring late in life tend to be transmitted exclusively to the same

sex, so that in this case extremely bright tints would not have been transmitted to the females. On the other

hand, ornaments of a less conspicuous kind, such as those possessed by the Eared and Cheer pheasants,

would not have been dangerous, and if they appeared during early youth, would generally have been

In addition to the effects of the partial transference of characters from the males to the females, some of the

differences between the females of closely allied species may be attributed to the direct or definite action of

the conditions of life. (11. See, on this subject, chap. xxiii. in the 'Variation of Animals and Plants under

Domestication.') With the males, any such action would generally have been masked by the brilliant colours

gained through sexual selection; but not so with the females. Each of the endless diversities in plumage which

we see in our domesticated birds is, of course, the result of some definite cause; and under natural and more

uniform conditions, some one tint, assuming that it was in no way injurious, would almost certainly sooner or

later prevail. The free intercrossing of the many individuals belonging to the same species would ultimately

No one doubts that both sexes of many birds have had their colours adapted for the sake of protection; and it

is possible that the females alone of some species may have been modified for this end. Although it would be

a difficult, perhaps an impossible process, as shewn in the last chapter, to convert one form of transmission

into another through selection, there would not be the least difficulty in adapting the colours of the female,

independently of those of the male, to surrounding objects, through the accumulation of variations which

were from the first limited in their transmission to the female sex. If the variations were not thus limited, the

bright tints of the male would be deteriorated or destroyed. Whether the females alone of many species have

been thus specially modified, is at present very doubtful. I wish I could follow Mr. Wallace to the full extent;

for the admission would remove some difficulties. Any variations which were of no service to the female as a

protection would be at once obliterated, instead of being lost simply by not being selected, or from free

intercrossing, or from being eliminated when transferred to the male and in any way injurious to him. Thus

the plumage of the female would be kept constant in character. It would also be a relief if we could admit that

the obscure tints of both sexes of many birds had been acquired and preserved for the sake of

protection,for example, of the hedgewarbler or kittywren (Accentor modularis and Troglodytes

vulgaris), with respect to which we have no sufficient evidence of the action of sexual selection. We ought,

however, to be cautious in concluding that colours which appear to us dull, are not attractive to the females of

certain species; we should bear in mind such cases as that of the common housesparrow, in which the male

differs much from the female, but does not exhibit any bright tints. No one probably will dispute that many

gallinaceous birds which live on the open ground, have acquired their present colours, at least in part, for the

sake of protection. We know how well they are thus concealed; we know that ptarmigans, whilst changing

from their winter to their summer plumage, both of which are protective, suffer greatly from birds of prey.

But can we believe that the very slight differences in tints and markings between, for instance, the female

blackgrouse and redgrouse serve as a protection? Are partridges, as they are now coloured, better protected

than if they had resembled quails? Do the slight differences between the females of the common pheasant, the

Japan and gold pheasants, serve as a protection, or might not their plumages have been interchanged with

impunity? From what Mr. Wallace has observed of the habits of certain gallinaceous birds in the East, he

thinks that such slight differences are beneficial. For myself, I will only say that I am not convinced.

Formerly when I was inclined to lay much stress on protection as accounting for the duller colours of female

birds, it occurred to me that possibly both sexes and the young might aboriginally have been equally bright

coloured; but that subsequently, the females from the danger incurred during incubation, and the young from

being inexperienced, had been rendered dull as a protection. But this view is not supported by any evidence,

and is not probable; for we thus in imagination expose during past times the females and the young to danger,

from which it has subsequently been necessary to shield their modified descendants. We have, also, to

reduce, through a gradual process of selection, the females and the young to almost exactly the same tints and

markings, and to transmit them to the corresponding sex and period of life. On the supposition that the

females and the young have partaken during each stage of the process of modification of a tendency to be as

brightly coloured as the males, it is also a somewhat strange fact that the females have never been rendered

dullcoloured without the young participating in the same change; for there are no instances, as far as I can

discover, of species with the females dull and the young bright coloured. A partial exception, however, is

offered by the young of certain woodpeckers, for they have "the whole upper part of the head tinged with

red," which afterwards either decreases into a mere circular red line in the adults of both sexes, or quite

disappears in the adult females. (12. Audubon, 'Ornith. Biography,' vol. i. p. 193. Macgillivray, 'History of

British Birds,' vol. iii. p. 85. See also the case before given of Indopicus carlotta.)

Finally, with respect to our present class of cases, the most probable view appears to be that successive

variations in brightness or in other ornamental characters, occurring in the males at a rather late period of life

have alone been preserved; and that most or all of these variations, owing to the late period of life at which

they appeared, have been from the first transmitted only to the adult male offspring. Any variations in

brightness occurring in the females or in the young, would have been of no service to them, and would not

have been selected; and moreover, if dangerous, would have been eliminated. Thus the females and the young

will either have been left unmodified, or (as is much more common) will have been partially modified by

receiving through transference from the males some of his successive variations. Both sexes have perhaps

been directly acted on by the conditions of life to which they have long been exposed: but the females from

not being otherwise much modified, will best exhibit any such effects. These changes and all others will have

been kept uniform by the free intercrossing of many individuals. In some cases, especially with ground birds,

the females and the young may possibly have been modified, independently of the males, for the sake of

This class is exactly the reverse of the last, for the females are here brighter coloured or more conspicuous

than the males; and the young, as far as they are known, resemble the adult males instead of the adult

females. But the difference between the sexes is never nearly so great as with many birds in the first class,

and the cases are comparatively rare. Mr. Wallace, who first called attention to the singular relation which

exists between the less bright colours of the males and their performing the duties of incubation, lays great

stress on this point (13. 'Westminster Review,' July 1867, and A. Murray, 'Journal of Travel,' 1868, p. 83.), as

a crucial test that obscure colours have been acquired for the sake of protection during the period of nesting.

A different view seems to me more probable. As the cases are curious and not numerous, I will briefly give

In one section of the genus Turnix, quaillike birds, the female is invariably larger than the male (being

nearly twice as large in one of the Australian species), and this is an unusual circumstance with the

Gallinaceae. In most of the species the female is more distinctly coloured and brighter than the male (14. For

the Australian species, see Gould's 'Handbook,' etc., vol. ii. pp. 178, 180, 186, and 188. In the British

Museum specimens of the Australian Plainwanderer (Pedionomus torquatus) may be seen, shewing similar

sexual differences.), but in some few species the sexes are alike. In Turnix taigoor of India the male "wants

the black on the throat and neck, and the whole tone of the plumage is lighter and less pronounced than that

of the female." The female appears to be noisier, and is certainly much more pugnacious than the male; so

that the females and not the males are often kept by the natives for fighting, like gamecocks. As male birds

are exposed by the English birdcatchers for a decoy near a trap, in order to catch other males by exciting

their rivalry, so the females of this Turnix are employed in India. When thus exposed the females soon begin

their "loud purring call, which can be heard a long way off, and any females within earshot run rapidly to

the spot, and commence fighting with the caged bird." In this way from twelve to twenty birds, all breeding

females, may be caught in the course of a single day. The natives assert that the females after laying their

eggs associate in flocks, and leave the males to sit on them. There is no reason to doubt the truth of this

assertion, which is supported by some observations made in China by Mr. Swinhoe. (15. Jerdon, 'Birds of

India,' vol. iii. p. 596. Mr. Swinhoe, in 'Ibis,' 1865, p. 542; 1866, pp. 131, 405.) Mr. Blyth believes, that the

The females of the three species of Painted Snipes (Rhynchaea, Fig. 62) "are not only larger but much more

richly coloured than the males." (16. Jerdon, 'Birds of India,' vol. iii. p. 677.) With all other birds in which the

trachea differs in structure in the two sexes it is more developed and complex in the male than in the female;

but in the Rhynchaea australis it is simple in the male, whilst in the female it makes four distinct convolutions

before entering the lungs. (17. Gould's 'Handbook to the Birds of Australia,' vol. ii. p. 275.) The female

therefore of this species has acquired an eminently masculine character. Mr. Blyth ascertained, by examining

many specimens, that the trachea is not convoluted in either sex of R. bengalensis, which species resembles

R. australis so closely, that it can hardly be distinguished except by its shorter toes. This fact is another

striking instance of the law that secondary sexual characters are often widely different in closelyallied

forms, though it is a very rare circumstance when such differences relate to the female sex. The young of both

sexes of R. bengalensis in their first plumage are said to resemble the mature male. (18. 'The Indian Field,'

Sept. 1858, p. 3.) There is also reason to believe that the male undertakes the duty of incubation, for Mr.

Swinhoe (19. 'Ibis,' 1866, p. 298.) found the females before the close of the summer associated in flocks, as

The females of Phalaropus fulicarius and P. hyperboreus are larger, and in their summer plumage "more gaily

attired than the males." But the difference in colour between the sexes is far from conspicuous. According to

Professor Steenstrup, the male alone of P. fulicarius undertakes the duty of incubation; this is likewise shewn

by the state of his breast feathers during the breedingseason. The female of the dotterel plover (Eudromias

morinellus) is larger than the male, and has the red and black tints on the lower surface, the white crescent on

the breast, and the stripes over the eyes, more strongly pronounced. The male also takes at least a share in

hatching the eggs; but the female likewise attends to the young. (20. For these several statements, see Mr.

Gould's 'Birds of Great Britain.' Prof. Newton informs me that he has long been convinced, from his own

observations and from those of others, that the males of the above named species take either the whole or a

large share of the duties of incubation, and that they "shew much greater devotion towards their young, when

in danger, than do the females." So it is, as he informs me, with Limosa lapponica and some few other

Waders, in which the females are larger and have more strongly contrasted colours than the males.) I have not

been able to discover whether with these species the young resemble the adult males more closely than the

adult females; for the comparison is somewhat difficult to make on account of the double moult.

Turning now to the ostrich Order: the male of the common cassowary (Casuarius galeatus) would be thought

by any one to be the female, from his smaller size and from the appendages and naked skin about his head

being much less brightly coloured; and I am informed by Mr. Bartlett that in the Zoological Gardens, it is

certainly the male alone who sits on the eggs and takes care of the young. (21. The natives of Ceram

(Wallace, 'Malay Archipelago,' vol. ii. p. 150) assert that the male and female sit alternately on the eggs; but

this assertion, as Mr. Bartlett thinks, may be accounted for by the female visiting the nest to lay her eggs.)

The female is said by Mr. T.W. Wood (22. The 'Student,' April 1870, p. 124.) to exhibit during the

breedingseason a most pugnacious disposition; and her wattles then become enlarged and more brilliantly

coloured. So again the female of one of the emus (Dromoeus irroratus) is considerably larger than the male,

and she possesses a slight topknot, but is otherwise indistinguishable in plumage. She appears, however, "to

have greater power, when angry or otherwise excited, of erecting, like a turkeycock, the feathers of her neck

and breast. She is usually the more courageous and pugilistic. She makes a deep hollow guttural boom

especially at night, sounding like a small gong. The male has a slenderer frame and is more docile, with no

voice beyond a suppressed hiss when angry, or a croak." He not only performs the whole duty of incubation,

but has to defend the young from their mother; "for as soon as she catches sight of her progeny she becomes

violently agitated, and notwithstanding the resistance of the father appears to use her utmost endeavours to

destroy them. For months afterwards it is unsafe to put the parents together, violent quarrels being the

inevitable result, in which the female generally comes off conqueror." (23. See the excellent account of the

habits of this bird under confinement, by Mr. A.W. Bennett, in 'Land and Water,' May 1868, p. 233.) So that

with this emu we have a complete reversal not only of the parental and incubating instincts, but of the usual

moral qualities of the two sexes; the females being savage, quarrelsome, and noisy, the males gentle and

good. The case is very different with the African ostrich, for the male is somewhat larger than the female and

has finer plumes with more strongly contrasted colours; nevertheless he undertakes the whole duty of

incubation. (24. Mr. Sclater, on the incubation of the Struthiones, 'Proc. Zool. Soc.' June 9, 1863. So it is with

the Rhea darwinii: Captain Musters says ('At Home with the Patagonians,' 1871, p. 128), that the male is

larger, stronger and swifter than the female, and of slightly darker colours; yet he takes sole charge of the

I will specify the few other cases known to me, in which the female is more conspicuously coloured than the

male, although nothing is known about the manner of incubation. With the carrionhawk of the Falkland

Islands (Milvago leucurus) I was much surprised to find by dissection that the individuals, which had all their

tints strongly pronounced, with the cere and legs orangecoloured, were the adult females; whilst those with

duller plumage and grey legs were the males or the young. In an Australian tree creeper (Climacteris

erythrops) the female differs from the male in "being adorned with beautiful, radiated, rufous markings on the

throat, the male having this part quite plain." Lastly, in an Australian nightjar "the female always exceeds

the male in size and in the brilliance of her tints; the males, on the other hand, have two white spots on the

primaries more conspicuous than in the female." (25. For the Milvago, see 'Zoology of the Voyage of the

"Beagle," Birds,' 1841, p. 16. For the Climacteris and nightjar (Eurostopodus), see Gould's 'Handbook to the

Birds of Australia,' vol. i. pp. 602 and 97. The New Zealand shieldrake (Tadorna variegata) offers a quite

anomalous case; the head of the female is pure white, and her back is redder than that of the male; the head of

the male is of a rich dark bronzed colour, and his back is clothed with finely pencilled slate coloured

feathers, so that altogether he may be considered as the more beautiful of the two. He is larger and more

pugnacious than the female, and does not sit on the eggs. So that in all these respects this species comes

under our first class of cases; but Mr. Sclater ('Proceedings of the Zoological Society,' 1866, p. 150) was

much surprised to observe that the young of both sexes, when about three months old, resembled in their dark

heads and necks the adult males, instead of the adult females; so that it would appear in this case that the

females have been modified, whilst the males and the young have retained a former state of plumage.)

We thus see that the cases in which female birds are more conspicuously coloured than the males, with the

young in their immature plumage resembling the adult males instead of the adult females, as in the previous

class, are not numerous, though they are distributed in various Orders. The amount of difference, also,

between the sexes is incomparably less than that which frequently occurs in the last class; so that the cause of

the difference, whatever it may have been, has here acted on the females either less energetically or less

persistently than on the males in the last class. Mr. Wallace believes that the males have had their colours

rendered less conspicuous for the sake of protection during the period of incubation; but the difference

between the sexes in hardly any of the foregoing cases appears sufficiently great for this view to be safely

accepted. In some of the cases, the brighter tints of the female are almost confined to the lower surface, and

the males, if thus coloured, would not have been exposed to danger whilst sitting on the eggs. It should also

be borne in mind that the males are not only in a slight degree less conspicuously coloured than the females,

but are smaller and weaker. They have, moreover, not only acquired the maternal instinct of incubation, but

are less pugnacious and vociferous than the females, and in one instance have simpler vocal organs. Thus an

almost complete transposition of the instincts, habits, disposition, colour, size, and of some points of

Now if we might assume that the males in the present class have lost some of that ardour which is usual to

their sex, so that they no longer search eagerly for the females; or, if we might assume that the females have

become much more numerous than the malesand in the case of one Indian Turnix the females are said to

be "much more commonly met with than the males" (26. Jerdon, 'Birds of India,' vol. iii. p. 598.)then it is

not improbable that the females would have been led to court the males, instead of being courted by them.

This indeed is the case to a certain extent with some birds, as we have seen with the peahen, wild turkey, and

certain kinds of grouse. Taking as our guide the habits of most male birds, the greater size and strength as

well as the extraordinary pugnacity of the females of the Turnix and emu, must mean that they endeavour to

drive away rival females, in order to gain possession of the male; and on this view all the facts become clear;

for the males would probably be most charmed or excited by the females which were the most attractive to

them by their bright colours, other ornaments, or vocal powers. Sexual selection would then do its work,

steadily adding to the attractions of the females; the males and the young being left not at all, or but little

In this class the sexes when adult resemble each other, and differ from the young. This occurs with many

birds of many kinds. The male robin can hardly be distinguished from the female, but the young are widely

different, with their mottled duskyolive and brown plumage. The male and female of the splendid scarlet

ibis are alike, whilst the young are brown; and the scarlet colour, though common to both sexes, is apparently

a sexual character, for it is not well developed in either sex under confinement; and a loss of colour often

occurs with brilliant males when they are confined. With many species of herons the young differ greatly

from the adults; and the summer plumage of the latter, though common to both sexes, clearly has a nuptial

character. Young swans are slatecoloured, whilst the mature birds are pure white; but it would be

superfluous to give additional instances. These differences between the young and the old apparently depend,

as in the last two classes, on the young having retained a former or ancient state of plumage, whilst the old of

both sexes have acquired a new one. When the adults are bright coloured, we may conclude from the remarks

just made in relation to the scarlet ibis and to many herons, and from the analogy of the species in the first

class, that such colours have been acquired through sexual selection by the nearly mature males; but that,

differently from what occurs in the first two classes, the transmission, though limited to the same age, has not

been limited to the same sex. Consequently, the sexes when mature resemble each other and differ from the

In this class the young and the adults of both sexes, whether brilliantly or obscurely coloured, resemble each

other. Such cases are, I think, more common than those in the last class. We have in England instances in the

kingfisher, some woodpeckers, the jay, magpie, crow, and many small dull coloured birds, such as the

hedgewarbler or kittywren. But the similarity in plumage between the young and the old is never complete,

and graduates away into dissimilarity. Thus the young of some members of the kingfisher family are not only

less vividly coloured than the adults, but many of the feathers on the lower surface are edged with brown (27.

Jerdon, 'Birds of India,' vol. i. pp. 222, 228. Gould's 'Handbook to the Birds of Australia,' vol. i. pp. 124,

130.),a vestige probably of a former state of the plumage. Frequently in the same group of birds, even

within the same genus, for instance in an Australian genus of parrakeets (Platycercus), the young of some

species closely resemble, whilst the young of other species differ considerably, from their parents of both

sexes, which are alike. (28. Gould, ibid. vol. ii. pp. 37, 46, 56.) Both sexes and the young of the common jay

are closely similar; but in the Canada jay (Perisoreus canadensis) the young differ so much from their parents

that they were formerly described as distinct species. (29. Audubon, 'Ornith. Biography,' vol. ii. p. 55.)

I may remark before proceeding that, under the present and next two classes of cases, the facts are so

complex and the conclusions so doubtful, that any one who feels no especial interest in the subject had better

The brilliant or conspicuous colours which characterise many birds in the present class, can rarely or never be

of service to them as a protection; so that they have probably been gained by the males through sexual

selection, and then transferred to the females and the young. It is, however, possible that the males may have

selected the more attractive females; and if these transmitted their characters to their offspring of both sexes,

the same results would follow as from the selection of the more attractive males by the females. But there is

evidence that this contingency has rarely, if ever, occurred in any of those groups of birds in which the sexes

are generally alike; for, if even a few of the successive variations had failed to be transmitted to both sexes,

the females would have slightly exceeded the males in beauty. Exactly the reverse occurs under nature; for, in

almost every large group in which the sexes generally resemble each other, the males of some few species are

in a slight degree more brightly coloured than the females. It is again possible that the females may have

selected the more beautiful males, these males having reciprocally selected the more beautiful females; but it

is doubtful whether this double process of selection would be likely to occur, owing to the greater eagerness

of one sex than the other, and whether it would be more efficient than selection on one side alone. It is,

therefore, the most probable view that sexual selection has acted, in the present class, as far as ornamental

characters are concerned, in accordance with the general rule throughout the animal kingdom, that is, on the

males; and that these have transmitted their graduallyacquired colours, either equally or almost equally, to

Another point is more doubtful, namely, whether the successive variations first appeared in the males after

had become nearly mature, or whilst quite young. In either case sexual selection must have acted on the male

when he had to compete with rivals for the possession of the female; and in both cases the characters thus

acquired have been transmitted to both sexes and all ages. But these characters if acquired by the males when

adult, may have been transmitted at first to the adults alone, and at some subsequent period transferred to the

young. For it is known that, when the law of inheritance at corresponding ages fails, the offspring often

inherit characters at an earlier age than that at which they first appeared in their parents. (30. 'Variation of

Animals and Plants under Domestication,' vol. ii. p. 79.) Cases apparently of this kind have been observed

with birds in a state of nature. For instance Mr. Blyth has seen specimens of Lanius rufus and of Colymbus

glacialis which had assumed whilst young, in a quite anomalous manner, the adult plumage of their parents.

(31. 'Charlesworth's Magazine of Natural History,' vol. i. 1837, pp. 305, 306.) Again, the young of the

common swan (Cygnus olor) do not cast off their dark feathers and become white until eighteen months or

two years old; but Dr. F. Forel has described the case of three vigorous young birds, out of a brood of four,

which were born pure white. These young birds were not albinos, as shewn by the colour of their beaks and

legs, which nearly resembled the same parts in the adults. (32. 'Bulletin de la Soc. Vaudoise des Sc. Nat.' vol.

x. 1869, p. 132. The young of the Polish swan, Cygnus immutabilis of Yarrell, are always white; but this

species, as Mr. Sclater informs me, is believed to be nothing more than a variety of the domestic swan

It may be worth while to illustrate the above three modes by which, in the present class, the two sexes and the

young may have come to resemble each other, by the curious case of the genus Passer. (33. I am indebted to

Mr. Blyth for information in regard to this genus. The sparrow of Palestine belongs to the subgenus

Petronia.) In the housesparrow (P. domesticus) the male differs much from the female and from the young.

The young and the females are alike, and resemble to a large extent both sexes and the young of the sparrow

of Palestine (P. brachydactylus), as well as of some allied species. We may therefore assume that the female

and young of the housesparrow approximately shew us the plumage of the progenitor of the genus. Now

with the treesparrow (P. montanus) both sexes and the young closely resemble the male of the

housesparrow; so that they have all been modified in the same manner, and all depart from the typical

colouring of their early progenitor. This may have been effected by a male ancestor of the treesparrow

having varied, firstly, when nearly mature; or, secondly, whilst quite young, and by having in either case

transmitted his modified plumage to the females and the young; or, thirdly, he may have varied when adult

and transmitted his plumage to both adult sexes, and, owing to the failure of the law of inheritance at

It is impossible to decide which of these three modes has generally prevailed throughout the present class of

cases. That the males varied whilst young, and transmitted their variations to their offspring of both sexes, is

the most probable. I may here add that I have, with little success, endeavoured, by consulting various works,

to decide how far the period of variation in birds has generally determined the transmission of characters to

one sex or to both. The two rules, often referred to (namely, that variations occurring late in life are

transmitted to one and the same sex, whilst those which occur early in life are transmitted to both sexes),

apparently hold good in the first (34. For instance, the males of Tanagra aestiva and Fringilla cyanea require

three years, the male of Fringilla ciris four years, to complete their beautiful plumage. (See Audubon, 'Ornith.

Biography,' vol. i. pp. 233, 280, 378). The Harlequin duck takes three years (ibid. vol. iii. p. 614). The male

of the Gold pheasant, as I hear from Mr. Jenner Weir, can be distinguished from the female when about three

months old, but he does not acquire his full splendour until the end of the September in the following year.),

second, and fourth classes of cases; but they fail in the third, often in the fifth (35. Thus the Ibis tantalus and

Grus americanus take four years, the Flamingo several years, and the Ardea ludovicana two years, before

they acquire their perfect plumage. See Audubon, ibid. vol. i. p. 221; vol. iii. pp. 133, 139, 211.), and in the

sixth small class. They apply, however, as far as I can judge, to a considerable majority of the species; and we

must not forget the striking generalisation by Dr. W. Marshall with respect to the protuberances on the heads

of birds. Whether or not the two rules generally hold good, we may conclude from the facts given in the

eighth chapter, that the period of variation is one important element in determining the form of transmission.

With birds it is difficult to decide by what standard we ought to judge of the earliness or lateness of the period

of variation, whether by the age in reference to the duration of life, or to the power of reproduction, or to the

number of moults through which the species passes. The moulting of birds, even within the same family,

sometimes differs much without any assignable cause. Some birds moult so early, that nearly all the body

feathers are cast off before the first wingfeathers are fully grown; and we cannot believe that this was the

primordial state of things. When the period of moulting has been accelerated, the age at which the colours of

the adult plumage are first developed will falsely appear to us to be earlier than it really is. This may be

illustrated by the practice followed by some birdfanciers, who pull out a few feathers from the breast of

nestling bullfinches, and from the head or neck of young goldpheasants, in order to ascertain their sex; for in

the males, these feathers are immediately replaced by coloured ones. (36. Mr. Blyth, in Charlesworth's

'Magazine of Natural History,' vol. i. 1837, p. 300. Mr. Bartlett has informed me in regard to gold pheasants.)

The actual duration of life is known in but few birds, so that we can hardly judge by this standard. And, with

reference to the period at which the power of reproduction is gained, it is a remarkable fact that various birds

occasionally breed whilst retaining their immature plumage. (37. I have noticed the following cases in

Audubon's 'Ornith. Biography.' The redstart of America (Muscapica ruticilla, vol. i. p. 203). The Ibis tantalus

takes four years to come to full maturity, but sometimes breeds in the second year (vol. iii. p. 133). The Grus

americanus takes the same time, but breeds before acquiring its full plumage (vol. iii. p. 211). The adults of

Ardea caerulea are blue, and the young white; and white, mottled, and mature blue birds may all be seen

breeding together (vol. iv. p. 58): but Mr. Blyth informs me that certain herons apparently are dimorphic, for

white and coloured individuals of the same age may be observed. The Harlequin duck (Anas histrionica,

Linn.) takes three years to acquire its full plumage, though many birds breed in the second year (vol. iii. p.

614). The Whiteheaded Eagle (Falco leucocephalus, vol. iii. p. 210) is likewise known to breed in its

immature state. Some species of Oriolus (according to Mr. Blyth and Mr. Swinhoe, in 'Ibis,' July 1863, p. 68)

The fact of birds breeding in their immature plumage seems opposed to the belief that sexual selection has

played as important a part, as I believe it has, in giving ornamental colours, plumes, etc., to the males, and, by

means of equal transmission, to the females of many species. The objection would be a valid one, if the

younger and less ornamented males were as successful in winning females and propagating their kind, as the

older and more beautiful males. But we have no reason to suppose that this is the case. Audubon speaks of

the breeding of the immature males of Ibis tantalus as a rare event, as does Mr. Swinhoe, in regard to the

immature males of Oriolus. (38. See footnote 37 above.) If the young of any species in their immature

plumage were more successful in winning partners than the adults, the adult plumage would probably soon be

lost, as the males would prevail, which retained their immature dress for the longest period, and thus the

character of the species would ultimately be modified. (39. Other animals, belonging to quite distinct classes,

are either habitually or occasionally capable of breeding before they have fully acquired their adult

characters. This is the case with the young males of the salmon. Several amphibians have been known to

breed whilst retaining their larval structure. Fritz Muller has shewn ('Facts and arguments for Darwin,' Eng.

trans. 1869, p. 79) that the males of several amphipod crustaceans become sexually mature whilst young; and

I infer that this is a case of premature breeding, because they have not as yet acquired their fullydeveloped

claspers. All such facts are highly interesting, as bearing on one means by which species may undergo great

modifications of character.) If, on the other hand, the young never succeeded in obtaining a female, the habit

of early reproduction would perhaps be sooner or later eliminated, from being superfluous and entailing

The plumage of certain birds goes on increasing in beauty during many years after they are fully mature; this

is the case with the train of the peacock, with some of the birds of paradise, and with the crest and plumes of

certain herons, for instance, the Ardea ludovicana. (40. Jerdon, 'Birds of India,' vol. iii. p. 507, on the

peacock. Dr. Marshall thinks that the older and more brilliant males of birds of paradise, have an advantage

over the younger males; see 'Archives Neerlandaises,' tom. vi. 1871.On Ardea, Audubon, ibid. vol. iii. p.

139.) But it is doubtful whether the continued development of such feathers is the result of the selection of

successive beneficial variations (though this is the most probable view with birds of paradise) or merely of

continuous growth. Most fishes continue increasing in size, as long as they are in good health and have plenty

The cases in this class are singularly complex; nor is this surprising, as they depend on inheritance, limited in

a greater or less degree in three different ways, namely, by sex, age, and the season of the year. In some cases

the individuals of the same species pass through at least five distinct states of plumage. With the species, in

which the male differs from the female during the summer season alone, or, which is rarer, during both

seasons (41. For illustrative cases, see vol. iv. of Macgillivray's 'History of British Birds;' on Tringa, etc., pp.

229, 271; on the Machetes, p. 172; on the Charadrius hiaticula, p. 118; on the Charadrius pluvialis, p. 94.),

the young generally resemble the females,as with the socalled goldfinch of North America, and

apparently with the splendid Maluri of Australia. (42. For the goldfinch of N. America, Fringilla tristis, Linn.,

see Audubon, 'Ornithological Biography,' vol. i. p. 172. For the Maluri, Gould's 'Handbook of the Birds of

Australia,' vol. i. p. 318.) With those species, the sexes of which are alike during both the summer and winter,

the young may resemble the adults, firstly, in their winter dress; secondly, and this is of much rarer

occurrence, in their summer dress; thirdly, they may be intermediate between these two states; and, fourthly,

they may differ greatly from the adults at all seasons. We have an instance of the first of these four cases in

one of the egrets of India (Buphus coromandus), in which the young and the adults of both sexes are white

With the gaper (Anastomus oscitans) of India we have a similar case, but the colours are reversed: for the

young and the adults of both sexes are grey and black during the winter, the adults becoming white during the

summer. (43. I am indebted to Mr. Blyth for information as to the Buphus; see also Jerdon, 'Birds of India,'

vol. iii. p. 749. On the Anastomus, see Blyth, in 'Ibis,' 1867, p. 173.) As an instance of the second case, the

young of the razorbill (Alca torda, Linn.), in an early state of plumage, are coloured like the adults during

the summer; and the young of the white crowned sparrow of North America (Fringilla leucophrys), as soon

as fledged, have elegant white stripes on their heads, which are lost by the young and the old during the

winter. (44. On the Alca, see Macgillivray, 'Hist. Brit. Birds,' vol. v. p. 347. On the Fringilla leucophrys,

Audubon, ibid. vol. ii. p. 89. I shall have hereafter to refer to the young of certain herons and egrets being

white.) With respect to the third case, namely, that of the young having an intermediate character between the

summer and winter adult plumages, Yarrell (45. 'History of British Birds,' vol. i. 1839, p. 159.) insists that

this occurs with many waders. Lastly, in regard to the young differing greatly from both sexes in their adult

summer and winter plumages, this occurs with some herons and egrets of North America and India,the

I will make only a few remarks on these complicated cases. When the young resemble the females in their

summer dress, or the adults of both sexes in their winter dress, the cases differ from those given under

Classes I. and III. only in the characters originally acquired by the males during the breedingseason, having

been limited in their transmission to the corresponding season. When the adults have a distinct summer and

winter plumage, and the young differ from both, the case is more difficult to understand. We may admit as

probable that the young have retained an ancient state of plumage; we can account by sexual selection for the

summer or nuptial plumage of the adults, but how are we to account for their distinct winter plumage? If we

could admit that this plumage serves in all cases as a protection, its acquirement would be a simple affair; but

there seems no good reason for this admission. It may be suggested that the widely different conditions of life

during the winter and summer have acted in a direct manner on the plumage; this may have had some effect,

but I have not much confidence in so great a difference as we sometimes see between the two plumages,

having been thus caused. A more probable explanation is, that an ancient style of plumage, partially modified

through the transference of some characters from the summer plumage, has been retained by the adults during

the winter. Finally, all the cases in our present class apparently depend on characters acquired by the adult

males, having been variously limited in their transmission according to age, season, and sex; but it would not

The cases in the present class, though occurring in various groups, are not numerous; yet it seems the most

natural thing that the young should at first somewhat resemble the adults of the same sex, and gradually

become more and more like them. The adult male blackcap (Sylvia atricapilla) has a black head, that of the

female being reddishbrown; and I am informed by Mr. Blyth, that the young of both sexes can be

distinguished by this character even as nestlings. In the family of thrushes an unusual number of similar cases

have been noticed; thus, the male blackbird (Turdus merula) can be distinguished in the nest from the female.

The two sexes of the mocking bird (Turdus polyglottus, Linn.) differ very little from each other, yet the males

can easily be distinguished at a very early age from the females by showing more pure white. (46. Audubon,

'Ornith. Biography,' vol. i. p. 113.) The males of a forestthrush and of a rock thrush (Orocetes

erythrogastra and Petrocincla cyanea) have much of their plumage of a fine blue, whilst the females are

brown; and the nestling males of both species have their main wing and tailfeathers edged with blue whilst

those of the female are edged with brown. (47. Mr. C.A. Wright, in 'Ibis,' vol. vi. 1864, p. 65. Jerdon, 'Birds

of India,' vol. i. p. 515. See also on the blackbird, Blyth in Charlesworth's 'Magazine of Natural History,' vol.

i. 1837, p. 113.) In the young blackbird the wing feathers assume their mature character and become black

after the others; on the other hand, in the two species just named the wingfeathers become blue before the

others. The most probable view with reference to the cases in the present class is that the males, differently

from what occurs in Class I., have transmitted their colours to their male offspring at an earlier age than that

at which they were first acquired; for, if the males had varied whilst quite young, their characters would

probably have been transmitted to both sexes. (48. The following additional cases may be mentioned; the

young males of Tanagra rubra can be distinguished from the young females (Audubon, 'Ornith. Biography,'

vol. iv. p. 392), and so it is within the nestlings of a blue nuthatch, Dendrophila frontalis of India (Jerdon,

'Birds of India,' vol. i. p. 389). Mr. Blyth also informs me that the sexes of the stonechat, Saxicola rubicola,

are distinguishable at a very early age. Mr. Salvin gives ('Proc. Zoolog. Soc.' 1870, p. 206) the case of a

In Aithurus polytmus, a hummingbird, the male is splendidly coloured black and green, and two of the

tailfeathers are immensely lengthened; the female has an ordinary tail and inconspicuous colours; now the

young males, instead of resembling the adult female, in accordance with the common rule, begin from the

first to assume the colours proper to their sex, and their tailfeathers soon become elongated. I owe this

information to Mr. Gould, who has given me the following more striking and as yet unpublished case. Two

hummingbirds belonging to the genus Eustephanus, both beautifully coloured, inhabit the small island of

Juan Fernandez, and have always been ranked as specifically distinct. But it has lately been ascertained that

the one which is of a rich chestnutbrown colour with a goldenred head, is the male, whilst the other which

is elegantly variegated with green and white with a metallic green head is the female. Now the young from

the first somewhat resemble the adults of the corresponding sex, the resemblance gradually becoming more

In considering this last case, if as before we take the plumage of the young as our guide, it would appear that

both sexes have been rendered beautiful independently; and not that one sex has partially transferred its

beauty to the other. The male apparently has acquired his bright colours through sexual selection in the same

manner as, for instance, the peacock or pheasant in our first class of cases; and the female in the same manner

as the female Rhynchaea or Turnix in our second class of cases. But there is much difficulty in understanding

how this could have been effected at the same time with the two sexes of the same species. Mr. Salvin states,

as we have seen in the eighth chapter, that with certain hummingbirds the males greatly exceed the females

in number, whilst with other species inhabiting the same country the females greatly exceed the males. If,

then, we might assume that during some former lengthened period the males of the Juan Fernandez species

had greatly exceeded the females in number, but that during another lengthened period the females had far

exceeded the males, we could understand how the males at one time, and the females at another, might have

been rendered beautiful by the selection of the brighter coloured individuals of either sex; both sexes

transmitting their characters to their young at a rather earlier age than usual. Whether this is the true

explanation I will not pretend to say; but the case is too remarkable to be passed over without notice.

We have now seen in all six classes, that an intimate relation exists between the plumage of the young and the

adults, either of one sex or both. These relations are fairly well explained on the principle that one sex this

being in the great majority of cases the malefirst acquired through variation and sexual selection bright

colours or other ornaments, and transmitted them in various ways, in accordance with the recognised laws of

inheritance. Why variations have occurred at different periods of life, even sometimes with species of the

same group, we do not know, but with respect to the form of transmission, one important determining cause

From the principle of inheritance at corresponding ages, and from any variations in colour which occurred in

the males at an early age not being then selectedon the contrary being often eliminated as

dangerouswhilst similar variations occurring at or near the period of reproduction have been preserved, it

follows that the plumage of the young will often have been left unmodified, or but little modified. We thus

get some insight into the colouring of the progenitors of our existing species. In a vast number of species in

five out of our six classes of cases, the adults of one sex or of both are bright coloured, at least during the

breeding season, whilst the young are invariably less brightly coloured than the adults, or are quite dull

coloured; for no instance is known, as far as I can discover, of the young of dullcoloured species displaying

bright colours, or of the young of brightcoloured species being more brilliant than their parents. In the

fourth class, however, in which the young and the old resemble each other, there are many species (though by

no means all), of which the young are brightcoloured, and as these form old groups, we may infer that their

early progenitors were likewise bright. With this exception, if we look to the birds of the world, it appears

that their beauty has been much increased since that period, of which their immature plumage gives us a

It will have been seen that I cannot follow Mr. Wallace in the belief that dull colours, when confined to the

females, have been in most cases specially gained for the sake of protection. There can, however, be no

doubt, as formerly remarked, that both sexes of many birds have had their colours modified, so as to escape

the notice of their enemies; or in some instances, so as to approach their prey unobserved, just as owls have

had their plumage rendered soft, that their flight may not be overheard. Mr. Wallace remarks (49.

'Westminster Review,' July 1867, p. 5.) that "it is only in the tropics, among forests which never lose their

foliage, that we find whole groups of birds, whose chief colour is green." It will be admitted by every one,

who has ever tried, how difficult it is to distinguish parrots in a leafcovered tree. Nevertheless, we must

remember that many parrots are ornamented with crimson, blue, and orange tints, which can hardly be

protective. Woodpeckers are eminently arboreal, but besides green species, there are many black, and

blackandwhite kindsall the species being apparently exposed to nearly the same dangers. It is therefore

probable that with treehaunting birds, stronglypronounced colours have been acquired through sexual

selection, but that a green tint has been acquired oftener than any other, from the additional advantage of

In regard to birds which live on the ground, every one admits that they are coloured so as to imitate the

surrounding surface. How difficult it is to see a partridge, snipe, W., certain plovers, larks, and

nightjars when crouched on ground. Animals inhabiting deserts offer the most striking cases, for the bare

surface affords no concealment, and nearly all the smaller quadrupeds, reptiles, and birds depend for safety

on their colours. Mr. Tristram has remarked in regard to the inhabitants of the Sahara, that all are protected by

their "isabelline or sandcolour." (50. 'Ibis,' 1859, vol. i. p. 429, et seq. Dr. Rohlfs, however, remarks to me in

a letter that according to his experience of the Sahara, this statement is too strong.) Calling to my recollection

the desertbirds of South America, as well as most of the groundbirds of Great Britain, it appeared to me

that both sexes in such cases are generally coloured nearly alike. Accordingly, I applied to Mr. Tristram with

respect to the birds of the Sahara, and he has kindly given me the following information. There are

twentysix species belonging to fifteen genera, which manifestly have their plumage coloured in a protective

manner; and this colouring is all the more striking, as with most of these birds it differs from that of their

congeners. Both sexes of thirteen out of the twentysix species are coloured in the same manner; but these

belong to genera in which this rule commonly prevails, so that they tell us nothing about the protective

colours being the same in both sexes of desertbirds. Of the other thirteen species, three belong to genera in

which the sexes usually differ from each other, yet here they have the sexes alike. In the remaining ten

species, the male differs from the female; but the difference is confined chiefly to the under surface of the

plumage, which is concealed when the bird crouches on the ground; the head and back being of the same

sand coloured hue in the two sexes. So that in these ten species the upper surfaces of both sexes have been

acted on and rendered alike, through natural selection, for the sake of protection; whilst the lower surfaces of

the males alone have been diversified, through sexual selection, for the sake of ornament. Here, as both sexes

are equally well protected, we clearly see that the females have not been prevented by natural selection from

inheriting the colours of their male parents; so that we must look to the law of sexuallylimited transmission.

In all parts of the world both sexes of many softbilled birds, especially those which frequent reeds or sedges,

are obscurely coloured. No doubt if their colours had been brilliant, they would have been much more

conspicuous to their enemies; but whether their dull tints have been specially gained for the sake of protection

seems, as far as I can judge, rather doubtful. It is still more doubtful whether such dull tints can have been

gained for the sake of ornament. We must, however, bear in mind that male birds, though dullcoloured,

often differ much from their females (as with the common sparrow), and this leads to the belief that such

colours have been gained through sexual selection, from being attractive. Many of the softbilled birds are

songsters; and a discussion in a former chapter should not be forgotten, in which it was shewn that the best

songsters are rarely ornamented with bright tints. It would appear that female birds, as a general rule, have

selected their mates either for their sweet voices or gay colours, but not for both charms combined. Some

species, which are manifestly coloured for the sake of protection, such as the jacksnipe, W., and

nightjar, are likewise marked and shaded, according to our standard of taste, with extreme elegance. In such

cases we may conclude that both natural and sexual selection have acted conjointly for protection and

ornament. Whether any bird exists which does not possess some special attraction, by which to charm the

opposite sex, may be doubted. When both sexes are so obscurely coloured that it would be rash to assume the

agency of sexual selection, and when no direct evidence can be advanced shewing that such colours serve as

a protection, it is best to own complete ignorance of the cause, or, which comes to nearly the same thing, to

Both sexes of many birds are conspicuously, though not brilliantly coloured, such as the numerous black,

white, or piebald species; and these colours are probably the result of sexual selection. With the common

blackbird, capercailzie, blackcock, black scoterduck (Oidemia), and even with one of the birds of paradise

(Lophorina atra), the males alone are black, whilst the females are brown or mottled; and there can hardly be

a doubt that blackness in these cases has been a sexually selected character. Therefore it is in some degree

probable that the complete or partial blackness of both sexes in such birds as crows, certain cockatoos, storks,

and swans, and many marine birds, is likewise the result of sexual selection, accompanied by equal

transmission to both sexes; for blackness can hardly serve in any case as a protection. With several birds, in

which the male alone is black, and in others in which both sexes are black, the beak or skin about the head is

brightly coloured, and the contrast thus afforded adds much to their beauty; we see this in the bright yellow

beak of the male blackbird, in the crimson skin over the eyes of the blackcock and capercailzie, in the

brightly and variously coloured beak of the scoterdrake (Oidemia), in the red beak of the chough (Corvus

graculus, Linn.), of the black swan, and the black stork. This leads me to remark that it is not incredible that

toucans may owe the enormous size of their beaks to sexual selection, for the sake of displaying the

diversified and vivid stripes of colour, with which these organs are ornamented. (51. No satisfactory

explanation has ever been offered of the immense size, and still less of the bright colours, of the toucan's

beak. Mr. Bates ('The Naturalist on the Amazons,' vol. ii. 1863, p. 341) states that they use their beaks for

reaching fruit at the extreme tips of the branches; and likewise, as stated by other authors, for extracting eggs

and young birds from the nests of other birds. But, as Mr. Bates admits, the beak "can scarcely be considered

a very perfectlyformed instrument for the end to which it is applied." The great bulk of the beak, as shewn

by its breadth, depth, as well as length, is not intelligible on the view, that it serves merely as an organ of

prehension. Mr. Belt believes ('The Naturalist in Nicaragua,' p. 197) that the principal use of the beak is as a

defence against enemies, especially to the female whilst nesting in a hole in a tree.) The naked skin, also, at

the base of the beak and round the eyes is likewise often brilliantly coloured; and Mr. Gould, in speaking of

one species (52. Rhamphastos carinatus, Gould's 'Monograph of Ramphastidae.'), says that the colours of the

beak "are doubtless in the finest and most brilliant state during the time of pairing." There is no greater

improbability that toucans should be encumbered with immense beaks, though rendered as light as possible

by their cancellated structure, for the display of fine colours (an object falsely appearing to us unimportant),

than that the male Argus pheasant and some other birds should be encumbered with plumes so long as to

In the same manner, as the males alone of various species are black, the females being dullcoloured; so in a

few cases the males alone are either wholly or partially white, as with the several bellbirds of South

America (Chasmorhynchus), the Antarctic goose (Bernicla antarctica), the silver pheasant, etc., whilst the

females are brown or obscurely mottled. Therefore, on the same principle as before, it is probable that both

sexes of many birds, such as white cockatoos, several egrets with their beautiful plumes, certain ibises, gulls,

terns, etc., have acquired their more or less completely white plumage through sexual selection. In some of

these cases the plumage becomes white only at maturity. This is the case with certain gannets, tropicbirds,

etc., and with the snowgoose (Anser hyperboreus). As the latter breeds on the "barren grounds," when not

covered with snow, and as it migrates southward during the winter, there is no reason to suppose that its

snowwhite adult plumage serves as a protection. In the Anastomus oscitans, we have still better evidence

that the white plumage is nuptial character, for it is developed only during the summer; the young in their

immature state, and the adults in their winter dress, being grey and black. With many kinds of gulls (Larus),

the head and neck become pure white during the summer, being grey or mottled during the winter and in the

young state. On the other hand, with the smaller gulls, or seamews (Gavia), and with some terns (Sterna),

exactly the reverse occurs; for the heads of the young birds during the first year, and of the adults during the

winter, are either pure white, or much paler coloured than during the breedingseason. These latter cases

offer another instance of the capricious manner in which sexual selection appears often to have acted. (53. On

Larus, Gavia, and Sterna, see Macgillivray, 'History of British Birds,' vol. v. pp. 515, 584, 626. On the Anser

hyperboreus, Audubon, 'Ornithological Biography,' vol. iv. p. 562. On the Anastomus, Mr. Blyth, in 'Ibis,'

That aquatic birds have acquired a white plumage so much oftener than terrestrial birds, probably depends on

their large size and strong powers of flight, so that they can easily defend themselves or escape from birds of

prey, to which moreover they are not much exposed. Consequently, sexual selection has not here been

interfered with or guided for the sake of protection. No doubt with birds which roam over the open ocean, the

males and females could find each other much more easily, when made conspicuous either by being perfectly

white or intensely black; so that these colours may possible serve the same end as the callnotes of many

landbirds. (54. It may be noticed that with vultures, which roam far and wide high in the air, like marine

birds over the ocean, three or four species are almost wholly or largely white, and that many others are black.

So that here again conspicuous colours may possibly aid the sexes in finding each other during the

breedingseason.) A white or black bird when it discovers and flies down to a carcase floating on the sea or

cast up on the beach, will be seen from a great distance, and will guide other birds of the same and other

species, to the prey; but as this would be a disadvantage to the first finders, the individuals which were the

whitest or blackest would not thus procure more food than the less strongly coloured individuals. Hence

conspicuous colours cannot have been gradually acquired for this purpose through natural selection.

As sexual selection depends on so fluctuating an element as taste, we can understand how it is that, within the

same group of birds having nearly the same habits, there should exist white or nearly white, as well as black,

or nearly black species,for instance, both white and black cockatoos, storks, ibises, swans, terns, and

petrels. Piebald birds likewise sometimes occur in the same groups together with black and white species; for

instance, the blacknecked swan, certain terns, and the common magpie. That a strong contrast in colour is

agreeable to birds, we may conclude by looking through any large collection, for the sexes often differ from

each other in the male having the pale parts of a purer white, and the variously coloured dark parts of still

It would even appear that mere novelty, or slight changes for the sake of change, have sometimes acted on

female birds as a charm, like changes of fashion with us. Thus the males of some parrots can hardly be said to

be more beautiful than the females, at least according to our taste, but they differ in such points, as in having

a rosecoloured collar instead of "a bright emeraldine narrow green collar"; or in the male having a black

collar instead of "a yellow demicollar in front," with a pale roseate instead of a plumblue head. (55. See

Jerdon on the genus Palaeornis, 'Birds of India,' vol. i. pp. 258260.) As so many male birds have elongated

tailfeathers or elongated crests for their chief ornament, the shortened tail, formerly described in the male of

a hummingbird, and the shortened crest of the male goosander, seem like one of the many changes of

Some members of the heron family offer a still more curious case of novelty in colouring having, as it

appears, been appreciated for the sake of novelty. The young of the Ardea asha are white, the adults being

dark slatecoloured; and not only the young, but the adults in their winter plumage, of the allied Buphus

coromandus are white, this colour changing into a rich goldenbuff during the breedingseason. It is

incredible that the young of these two species, as well as of some other members of the same family (56. The

young of Ardea rufescens and A. caerulea of the United States are likewise white, the adults being coloured

in accordance with their specific names. Audubon ('Ornithological Biography,' vol. iii. p. 416; vol. iv. p. 58)

seems rather pleased at the thought that this remarkable change of plumage will greatly "disconcert the

systematists."), should for any special purpose have been rendered pure white and thus made conspicuous to

their enemies; or that the adults of one of these two species should have been specially rendered white during

the winter in a country which is never covered with snow. On the other hand we have good reason to believe

that whiteness has been gained by many birds as a sexual ornament. We may therefore conclude that some

early progenitor of the Ardea asha and the Buphus acquired a white plumage for nuptial purposes, and

transmitted this colour to their young; so that the young and the old became white like certain existing egrets;

and that the whiteness was afterwards retained by the young, whilst it was exchanged by the adults for more

stronglypronounced tints. But if we could look still further back to the still earlier progenitors of these two

species, we should probably see the adults darkcoloured. I infer that this would be the case, from the

analogy of many other birds, which are dark whilst young, and when adult are white; and more especially

from the case of the Ardea gularis, the colours of which are the reverse of those of A. asha, for the young are

darkcoloured and the adults white, the young having retained a former state of plumage. It appears therefore

that, during a long line of descent, the adult progenitors of the Ardea asha, the Buphus, and of some allies,

have undergone the following changes of colour: first, a dark shade; secondly, pure white; and thirdly, owing

to another change of fashion (if I may so express myself), their present slaty, reddish, or goldenbuff tints.

These successive changes are intelligible only on the principle of novelty having been admired by birds for its

Several writers have objected to the whole theory of sexual selection, by assuming that with animals and

savages the taste of the female for certain colours or other ornaments would not remain constant for many

generations; that first one colour and then another would be admired, and consequently that no permanent

effect could be produced. We may admit that taste is fluctuating, but it is not quite arbitrary. It depends much

on habit, as we see in mankind; and we may infer that this would hold good with birds and other animals.

Even in our own dress, the general character lasts long, and the changes are to a certain extent graduated.

Abundant evidence will be given in two places in a future chapter, that savages of many races have admired

for many generations the same cicatrices on the skin, the same hideously perforated lips, nostrils, or ears,

distorted heads, etc.; and these deformities present some analogy to the natural ornaments of various animals.

Nevertheless, with savages such fashions do not endure for ever, as we may infer from the differences in this

respect between allied tribes on the same continent. So again the raisers of fancy animals certainly have

admired for many generations and still admire the same breeds; they earnestly desire slight changes, which

are considered as improvements, but any great or sudden change is looked at as the greatest blemish. With

birds in a state of nature we have no reason to suppose that they would admire an entirely new style of

coloration, even if great and sudden variations often occurred, which is far from being the case. We know that

dovecot pigeons do not willingly associate with the variously coloured fancy breeds; that albino birds do not

commonly get partners in marriage; and that the black ravens of the Feroe Islands chase away their piebald

brethren. But this dislike of a sudden change would not preclude their appreciating slight changes, any more

than it does in the case of man. Hence with respect to taste, which depends on many elements, but partly on

habit and partly on a love of novelty, there seems no improbability in animals admiring for a very long period

the same general style of ornamentation or other attractions, and yet appreciating slight changes in colours,

Most male birds are highly pugnacious during the breedingseason, and some possess weapons adapted for

fighting with their rivals. But the most pugnacious and the best armed males rarely or never depend for

success solely on their power to drive away or kill their rivals, but have special means for charming the

female. With some it is the power of song, or of giving forth strange cries, or instrumental music, and the

males in consequence differ from the females in their vocal organs, or in the structure of certain feathers.

From the curiously diversified means for producing various sounds, we gain a high idea of the importance of

this means of courtship. Many birds endeavour to charm the females by love dances or antics, performed on

the ground or in the air, and sometimes at prepared places. But ornaments of many kinds, the most brilliant

tints, combs and wattles, beautiful plumes, elongated feathers, topknots, and so forth, are by far the

commonest means. In some cases mere novelty appears to have acted as a charm. The ornaments of the males

must be highly important to them, for they have been acquired in not a few cases at the cost of increased

danger from enemies, and even at some loss of power in fighting with their rivals. The males of very many

species do not assume their ornamental dress until they arrive at maturity, or they assume it only during the

breedingseason, or the tints then become more vivid. Certain ornamental appendages become enlarged,

turgid, and brightly coloured during the act of courtship. The males display their charms with elaborate care

and to the best effect; and this is done in the presence of the females. The courtship is sometimes a prolonged

affair, and many males and females congregate at an appointed place. To suppose that the females do not

appreciate the beauty of the males, is to admit that their splendid decorations, all their pomp and display, are

useless; and this is incredible. Birds have fine powers of discrimination, and in some few instances it can be

shewn that they have a taste for the beautiful. The females, moreover, are known occasionally to exhibit a

If it be admitted that the females prefer, or are unconsciously excited by the more beautiful males, then the

males would slowly but surely be rendered more and more attractive through sexual selection. That it is this

sex which has been chiefly modified, we may infer from the fact that, in almost every genus where the sexes

differ, the males differ much more from one another than do the females; this is well shewn in certain

closelyallied representative species, in which the females can hardly be distinguished, whilst the males are

quite distinct. Birds in a state of nature offer individual differences which would amply suffice for the work

of sexual selection; but we have seen that they occasionally present more strongly marked variations which

recur so frequently that they would immediately be fixed, if they served to allure the female. The laws of

variation must determine the nature of the initial changes, and will have largely influenced the final result.

The gradations, which may be observed between the males of allied species, indicate the nature of the steps

through which they have passed. They explain also in the most interesting manner how certain characters

have originated, such as the indented ocelli on the tailfeathers of the peacock, and the ballandsocket

ocelli on the wingfeathers of the Argus pheasant. It is evident that the brilliant colours, topknots, fine

plumes, etc., of many male birds cannot have been acquired as a protection; indeed, they sometimes lead to

danger. That they are not due to the direct and definite action of the conditions of life, we may feel assured,

because the females have been exposed to the same conditions, and yet often differ from the males to an

extreme degree. Although it is probable that changed conditions acting during a lengthened period have in

some cases produced a definite effect on both sexes, or sometimes on one sex alone, the more important

result will have been an increased tendency to vary or to present more stronglymarked individual

differences; and such differences will have afforded an excellent ground work for the action of sexual

The laws of inheritance, irrespectively of selection, appear to have determined whether the characters

acquired by the males for the sake of ornament, for producing various sounds, and for fighting together, have

been transmitted to the males alone or to both sexes, either permanently, or periodically during certain

seasons of the year. Why various characters should have been transmitted sometimes in one way and

sometimes in another, is not in most cases known; but the period of variability seems often to have been the

determining cause. When the two sexes have inherited all characters in common they necessarily resemble

each other; but as the successive variations may be differently transmitted, every possible gradation may be

found, even within the same genus, from the closest similarity to the widest dissimilarity between the sexes.

With many closelyallied species, following nearly the same habits of life, the males have come to differ

from each other chiefly through the action of sexual selection; whilst the females have come to differ chiefly

from partaking more or less of the characters thus acquired by the males. The effects, moreover, of the

definite action of the conditions of life, will not have been masked in the females, as in the males, by the

accumulation through sexual selection of stronglypronounced colours and other ornaments. The individuals

of both sexes, however affected, will have been kept at each successive period nearly uniform by the free

With species, in which the sexes differ in colour, it is possible or probable that some of the successive

variations often tended to be transmitted equally to both sexes; but that when this occurred the females were

prevented from acquiring the bright colours of the males, by the destruction which they suffered during

incubation. There is no evidence that it is possible by natural selection to convert one form of transmission

into another. But there would not be the least difficulty in rendering a female dullcoloured, the male being

still kept bright coloured, by the selection of successive variations, which were from the first limited in their

transmission to the same sex. Whether the females of many species have actually been thus modified, must at

present remain doubtful. When, through the law of the equal transmission of characters to both sexes, the

females were rendered as conspicuously coloured as the males, their instincts appear often to have been

In one small and curious class of cases the characters and habits of the two sexes have been completely

transposed, for the females are larger, stronger, more vociferous and brighter coloured than the males. They

have, also, become so quarrelsome that they often fight together for the possession of the males, like the

males of other pugnacious species for the possession of the females. If, as seems probable, such females

habitually drive away their rivals, and by the display of their bright colours or other charms endeavour to

attract the males, we can understand how it is that they have gradually been rendered, by sexual selection and

sexually limited transmission, more beautiful than the malesthe latter being left unmodified or only

Whenever the law of inheritance at corresponding ages prevails but not that of sexuallylimited transmission,

then if the parents vary late in life and we know that this constantly occurs with our poultry, and

occasionally with other birdsthe young will be left unaffected, whilst the adults of both sexes will be

modified. If both these laws of inheritance prevail and either sex varies late in life, that sex alone will be

modified, the other sex and the young being unaffected. When variations in brightness or in other

conspicuous characters occur early in life, as no doubt often happens, they will not be acted on through

sexual selection until the period of reproduction arrives; consequently if dangerous to the young, they will be

eliminated through natural selection. Thus we can understand how it is that variations arising late in life have

so often been preserved for the ornamentation of the males; the females and the young being left almost

unaffected, and therefore like each other. With species having a distinct summer and winter plumage, the

males of which either resemble or differ from the females during both seasons or during the summer alone,

the degrees and kinds of resemblance between the young and the old are exceedingly complex; and this

complexity apparently depends on characters, first acquired by the males, being transmitted in various ways

As the young of so many species have been but little modified in colour and in other ornaments, we are

enabled to form some judgment with respect to the plumage of their early progenitors; and we may infer that

the beauty of our existing species, if we look to the whole class, has been largely increased since that period,

of which the immature plumage gives us an indirect record. Many birds, especially those which live much on

the ground, have undoubtedly been obscurely coloured for the sake of protection. In some instances the upper

exposed surface of the plumage has been thus coloured in both sexes, whilst the lower surface in the males

alone has been variously ornamented through sexual selection. Finally, from the facts given in these four

chapters, we may conclude that weapons for battle, organs for producing sound, ornaments of many kinds,

bright and conspicuous colours, have generally been acquired by the males through variation and sexual

selection, and have been transmitted in various ways according to the several laws of inheritancethe

females and the young being left comparatively but little modified. (57. I am greatly indebted to the kindness

of Mr. Sclater for having looked over these four chapters on birds, and the two following ones on mammals.

In this way I have been saved from making mistakes about the names of the species, and from stating

anything as a fact which is known to this distinguished naturalist to be erroneous. But, of course, he is not at

all answerable for the accuracy of the statements quoted by me from various authorities.)

The law of battleSpecial weapons, confined to the malesCause of absence of weapons in the

femaleWeapons common to both sexes, yet primarily acquired by the maleOther uses of such

weaponsTheir high importance Greater size of the maleMeans of defenceOn the preference shown

With mammals the male appears to win the female much more through the law of battle than through the

display of his charms. The most timid animals, not provided with any special weapons for fighting, engage in

desperate conflicts during the season of love. Two male hares have been seen to fight together until one was

killed; male moles often fight, and sometimes with fatal results; male squirrels engage in frequent contests,

"and often wound each other severely"; as do male beavers, so that "hardly a skin is without scars." (1. See

Waterton's account of two hares fighting, 'Zoologist,' vol. i. 1843, p. 211. On moles, Bell, 'Hist. of British

Quadrupeds,' 1st ed., p. 100. On squirrels, Audubon and Bachman, Viviparous Quadrupeds of N. America,

1846, p. 269. On beavers, Mr. A.H. Green, in 'Journal of Linnean Society, Zoology,' vol. x. 1869, p. 362.) I

observed the same fact with the hides of the guanacoes in Patagonia; and on one occasion several were so

absorbed in fighting that they fearlessly rushed close by me. Livingstone speaks of the males of the many

animals in Southern Africa as almost invariably shewing the scars received in former contests.

The law of battle prevails with aquatic as with terrestrial mammals. It is notorious how desperately male seals

fight, both with their teeth and claws, during the breedingseason; and their hides are likewise often covered

with scars. Male spermwhales are very jealous at this season; and in their battles "they often lock their jaws

together, and turn on their sides and twist about"; so that their lower jaws often become distorted. (2. On the

battles of seals, see Capt. C. Abbott in 'Proc. Zool. Soc.' 1868, p. 191; Mr. R. Brown, ibid. 1868, p. 436; also

L. Lloyd, 'Game Birds of Sweden,' 1867, p. 412; also Pennant. On the spermwhale see Mr. J.H. Thompson,

All male animals which are furnished with special weapons for fighting, are well known to engage in fierce

battles. The courage and the desperate conflicts of stags have often been described; their skeletons have been

found in various parts of the world, with the horns inextricably locked together, shewing how miserably the

victor and vanquished had perished. (3. See Scrope ('Art of Deerstalking,' p. 17) on the locking of the horns

with the Cervus elaphus. Richardson, in 'Fauna Bor. Americana,' 1829, p. 252, says that the wapiti, moose,

and reindeer have been found thus locked together. Sir. A. Smith found at the Cape of Good Hope the

skeletons of two gnus in the same condition.) No animal in the world is so dangerous as an elephant in must.

Lord Tankerville has given me a graphic description of the battles between the wild bulls in Chillingham

Park, the descendants, degenerated in size but not in courage, of the gigantic Bos primigenius. In 1861

several contended for mastery; and it was observed that two of the younger bulls attacked in concert the old

leader of the herd, overthrew and disabled him, so that he was believed by the keepers to be lying mortally

wounded in a neighbouring wood. But a few days afterwards one of the young bulls approached the wood

alone; and then the "monarch of the chase," who had been lashing himself up for vengeance, came out and, in

a short time, killed his antagonist. He then quietly joined the herd, and long held undisputed sway. Admiral

Sir B.J. Sulivan informs me that, when he lived in the Falkland Islands, he imported a young English stallion,

which frequented the hills near Port William with eight mares. On these hills there were two wild stallions,

each with a small troop of mares; "and it is certain that these stallions would never have approached each

other without fighting. Both had tried singly to fight the English horse and drive away his mares, but had

failed. One day they came in TOGETHER and attacked him. This was seen by the capitan who had charge of

the horses, and who, on riding to the spot, found one of the two stallions engaged with the English horse,

whilst the other was driving away the mares, and had already separated four from the rest. The capitan settled

the matter by driving the whole party into the corral, for the wild stallions would not leave the mares."

Male animals which are provided with efficient cutting or tearing teeth for the ordinary purposes of life, such

as the carnivora, insectivora, and rodents, are seldom furnished with weapons especially adapted for fighting

with their rivals. The case is very different with the males of many other animals. We see this in the horns of

stags and of certain kinds of antelopes in which the females are hornless. With many animals the canine teeth

in the upper or lower jaw, or in both, are much larger in the males than in the females, or are absent in the

latter, with the exception sometimes of a hidden rudiment. Certain antelopes, the muskdeer, camel, horse,

boar, various apes, seals, and the walrus, offer instances. In the females of the walrus the tusks are sometimes

quite absent. (4. Mr. Lamont ('Seasons with the SeaHorses,' 1861, p. 143) says that a good tusk of the male

walrus weighs 4 pounds, and is longer than that of the female, which weighs about 3 pounds. The males are

described as fighting ferociously. On the occasional absence of the tusks in the female, see Mr. R. Brown,

'Proceedings, Zoological Society,' 1868, p. 429.) In the male elephant of India and in the male dugong (5.

Owen, 'Anatomy of Vertebrates,' vol. iii. p. 283.) the upper incisors form offensive weapons. In the male

narwhal the left canine alone is developed into the wellknown, spirallytwisted, socalled horn, which is

sometimes from nine to ten feet in length. It is believed that the males use these horns for fighting together;

for "an unbroken one can rarely be got, and occasionally one may be found with the point of another jammed

into the broken place." (6. Mr. R. Brown, in 'Proc. Zool. Soc.' 1869, p. 553. See Prof. Turner, in 'Journal of

Anat. and Phys.' 1872, p. 76, on the homological nature of these tusks. Also Mr. J.W. Clarke on two tusks

being developed in the males, in 'Proceedings of the Zoological Society,' 1871, p. 42.) The tooth on the

opposite side of the head in the male consists of a rudiment about ten inches in length, which is embedded in

the jaw; but sometimes, though rarely, both are equally developed on the two sides. In the female both are

always rudimentary. The male cachalot has a larger head than that of the female, and it no doubt aids him in

his aquatic battles. Lastly, the adult male ornithorhynchus is provided with a remarkable apparatus, namely a

spur on the foreleg, closely resembling the poisonfang of a venomous snake; but according to Harting, the

secretion from the gland is not poisonous; and on the leg of the female there is a hollow, apparently for the

reception of the spur. (7. Owen on the cachalot and Ornithorhynchus, ibid. vol. iii. pp. 638, 641. Harting is

quoted by Dr. Zouteveen in the Dutch translation of this work, vol. ii. p. 292.)

When the males are provided with weapons which in the females are absent, there can be hardly a doubt that

these serve for fighting with other males; and that they were acquired through sexual selection, and were

transmitted to the male sex alone. It is not probable, at least in most cases, that the females have been

prevented from acquiring such weapons, on account of their being useless, superfluous, or in some way

injurious. On the contrary, as they are often used by the males for various purposes, more especially as a

defence against their enemies, it is a surprising fact that they are so poorly developed, or quite absent, in the

females of so many animals. With female deer the development during each recurrent season of great

branching horns, and with female elephants the development of immense tusks, would be a great waste of

vital power, supposing that they were of no use to the females. Consequently, they would have tended to be

eliminated in the female through natural selection; that is, if the successive variations were limited in their

transmission to the female sex, for otherwise the weapons of the males would have been injuriously affected,

and this would have been a greater evil. On the whole, and from the consideration of the following facts, it

seems probable that when the various weapons differ in the two sexes, this has generally depended on the

As the reindeer is the one species in the whole family of Deer, in which the female is furnished with horns,

though they are somewhat smaller, thinner, and less branched than in the male, it might naturally be thought

that, at least in this case, they must be of some special service to her. The female retains her horns from the

time when they are fully developed, namely, in September, throughout the winter until April or May, when

she brings forth her young. Mr. Crotch made particular enquiries for me in Norway, and it appears that the

females at this season conceal themselves for about a fortnight in order to bring forth their young, and then

reappear, generally hornless. In Nova Scotia, however, as I hear from Mr. H. Reeks, the female sometimes

retains her horns longer. The male on the other hand casts his horns much earlier, towards the end of

November. As both sexes have the same requirements and follow the same habits of life, and as the male is

destitute of horns during the winter, it is improbable that they can be of any special service to the female

during this season, which includes the larger part of the time during which she is horned. Nor is it probable

that she can have inherited horns from some ancient progenitor of the family of deer, for, from the fact of the

females of so many species in all quarters of the globe not having horns, we may conclude that this was the

primordial character of the group. (8. On the structure and shedding of the horns of the reindeer, Hoffberg,

'Amoenitates Acad.' vol. iv. 1788, p. 149. See Richardson, 'Fauna Bor. Americana,' p. 241, in regard to the

American variety or species: also Major W. Ross King, 'The Sportsman in Canada,' 1866, p. 80.

The horns of the reindeer are developed at a most unusually early age; but what the cause of this may be is

not known. The effect has apparently been the transference of the horns to both sexes. We should bear in

mind that horns are always transmitted through the female, and that she has a latent capacity for their

development, as we see in old or diseased females. (9. Isidore Geoffroy St.Hilaire, 'Essais de Zoolog.

Generale,' 1841, p. 513. Other masculine characters, besides the horns, are sometimes similarly transferred to

the female; thus Mr. Boner, in speaking of an old female chamois ('Chamois Hunting in the Mountains of

Bavaria,' 1860, 2nd ed., p. 363), says, "not only was the head very malelooking, but along the back there

was a ridge of long hair, usually to be found only in bucks.") Moreover the females of some other species of

deer exhibit, either normally or occasionally, rudiments of horns; thus the female of Cervulus moschatus has

"bristly tufts, ending in a knob, instead of a horn"; and "in most specimens of the female wapiti (Cervus

canadensis) there is a sharp bony protuberance in the place of the horn." (10. On the Cervulus, Dr. Gray,

'Catalogue of Mammalia in the British Museum,' part iii. p. 220. On the Cervus canadensis or wapiti, see

Hon. J.D. Caton, 'Ottawa Academy of Nat. Sciences,' May 1868, p. 9.) From these several considerations we

may conclude that the possession of fairly welldeveloped horns by the female reindeer, is due to the males

having first acquired them as weapons for fighting with other males; and secondarily to their development

from some unknown cause at an unusually early age in the males, and their consequent transference to both

Turning to the sheathhorned ruminants: with antelopes a graduated series can be formed, beginning with

species, the females of which are completely destitute of hornspassing on to those which have horns so

small as to be almost rudimentary (as with the Antilocapra americana, in which species they are present in

only one out of four or five females (11. I am indebted to Dr. Canfield for this information; see also his paper

in the 'Proceedings of the Zoological Society,' 1866, p. 105.))to those which have fairly developed horns,

but manifestly smaller and thinner than in the male and sometimes of a different shape (12. For instance the

horns of the female Ant. euchore resemble those of a distinct species, viz. the Ant. dorcas var. Corine, see

Desmarest, 'Mammalogie,' p. 455.),and ending with those in which both sexes have horns of equal size. As

with the reindeer, so with antelopes, there exists, as previously shewn, a relation between the period of the

development of the horns and their transmission to one or both sexes; it is therefore probable that their

presence or absence in the females of some species, and their more or less perfect condition in the females of

other species, depends, not on their being of any special use, but simply on inheritance. It accords with this

view that even in the same restricted genus both sexes of some species, and the males alone of others, are

thus provided. It is also a remarkable fact that, although the females of Antilope bezoartica are normally

destitute of horns, Mr. Blyth has seen no less than three females thus furnished; and there was no reason to

In all the wild species of goats and sheep the horns are larger in the male than in the female, and are

sometimes quite absent in the latter. (13. Gray, 'Catalogue of Mammalia, the British Museum,' part iii. 1852,

p. 160.) In several domestic breeds of these two animals, the males alone are furnished with horns; and in

some breeds, for instance, in the sheep of North Wales, though both sexes are properly horned, the ewes are

very liable to be hornless. I have been informed by a trustworthy witness, who purposely inspected a flock of

these same sheep during the lambing season, that the horns at birth are generally more fully developed in the

male than in the female. Mr. J. Peel crossed his Lonk sheep, both sexes of which always bear horns, with

hornless Leicesters and hornless Shropshire Downs; and the result was that the male offspring had their horns

considerably reduced, whilst the females were wholly destitute of them. These several facts indicate that,

with sheep, the horns are a much less firmly fixed character in the females than in the males; and this leads us

With the adult muskox (Ovibos moschatus) the horns of the male are larger than those of the female, and in

the latter the bases do not touch. (14. Richardson, 'Fauna Bor. Americana,' p. 278.) In regard to ordinary

cattle Mr. Blyth remarks: "In most of the wild bovine animals the horns are both longer and thicker in the bull

than in the cow, and in the cowbanteng (Bos sondaicus) the horns are remarkably small, and inclined much

backwards. In the domestic races of cattle, both of the humped and humpless types, the horns are short and

thick in the bull, longer and more slender in the cow and ox; and in the Indian buffalo, they are shorter and

thicker in the bull, longer and more slender in the cow. In the wild gaour (B. gaurus) the horns are mostly

both longer and thicker in the bull than in the cow." (15. 'Land and Water,' 1867, p. 346.) Dr. Forsyth Major

also informs me that a fossil skull, believed to be that of the female Bos etruscus, has been found in Val

d'Arno, which is wholly without horns. In the Rhinoceros simus, as I may add, the horns of the female are

generally longer but less powerful than in the male; and in some other species of rhinoceros they are said to

be shorter in the female. (16. Sir Andrew Smith, 'Zoology of S. Africa,' pl. xix. Owen, 'Anatomy of

Vertebrates,' vol. iii. p. 624.) From these various facts we may infer as probable that horns of all kinds, even

when they are equally developed in the two sexes, were primarily acquired by the male in order to conquer

The effects of castration deserve notice, as throwing light on this same point. Stags after the operation never

renew their horns. The male reindeer, however, must be excepted, as after castration he does renew them.

This fact, as well as the possession of horns by both sexes, seems at first to prove that the horns in this

species do not constitute a sexual character (17. This is the conclusion of Seidlitz, 'Die Darwinsche Theorie,'

1871, p. 47.); but as they are developed at a very early age, before the sexes differ in constitution, it is not

surprising that they should be unaffected by castration, even if they were aboriginally acquired by the male.

With sheep both sexes properly bear horns; and I am informed that with Welch sheep the horns of the males

are considerably reduced by castration; but the degree depends much on the age at which the operation is

performed, as is likewise the case with other animals. Merino rams have large horns, whilst the ewes

"generally speaking are without horns"; and in this breed castration seems to produce a somewhat greater

effect, so that if performed at an early age the horns "remain almost undeveloped." (18. I am much obliged to

Prof. Victor Carus, for having made enquiries for me in Saxony on this subject. H. von Nathusius

('Viehzucht,' 1872, p. 64) says that the horns of sheep castrated at an early period, either altogether disappear

or remain as mere rudiments; but I do not know whether he refers to merinos or to ordinary breeds.) On the

Guinea coast there is a breed in which the females never bear horns, and, as Mr. Winwood Reade informs me,

the rams after castration are quite destitute of them. With cattle, the horns of the males are much altered by

castration; for instead of being short and thick, they become longer than those of the cow, but otherwise

resemble them. The Antilope bezoartica offers a somewhat analogous case: the males have long straight

spiral horns, nearly parallel to each other, and directed backwards; the females occasionally bear horns, but

these when present are of a very different shape, for they are not spiral, and spreading widely, bend round

with the points forwards. Now it is a remarkable fact that, in the castrated male, as Mr. Blyth informs me, the

horns are of the same peculiar shape as in the female, but longer and thicker. If we may judge from analogy,

the female probably shews us, in these two cases of cattle and the antelope, the former condition of the horns

in some early progenitor of each species. But why castration should lead to the reappearance of an early

condition of the horns cannot be explained with any certainty. Nevertheless, it seems probable, that in nearly

the same manner as the constitutional disturbance in the offspring, caused by a cross between two distinct

species or races, often leads to the reappearance of longlost characters (19. I have given various experiments

and other evidence proving that this is the case, in my 'Variation of Animals and Plants under Domestication,'

vol. ii. 1868, pp. 3947.); so here, the disturbance in the constitution of the individual, resulting from

The tusks of the elephant, in the different species or races, differ according to sex, nearly as do the horns of

ruminants. In India and Malacca the males alone are provided with welldeveloped tusks. The elephant of

Ceylon is considered by most naturalists as a distinct race, but by some as a distinct species, and here "not

one in a hundred is found with tusks, the few that possess them being exclusively males." (20. Sir J. Emerson

Tennent, 'Ceylon,' 1859, vol. ii. p. 274. For Malacca, 'Journal of Indian Archipelago,' vol. iv. p. 357.) The

African elephant is undoubtedly distinct, and the female has large welldeveloped tusks, though not so large

These differences in the tusks of the several races and species of elephantsthe great variability of the horns

of deer, as notably in the wild reindeerthe occasional presence of horns in the female Antilope Bezoartica,

and their frequent absence in the female of Antilocapra americanathe presence of two tusks in some few

male narwhalsthe complete absence of tusks in some female walrusesare all instances of the extreme

variability of secondary sexual characters, and of their liability to differ in closelyallied forms.

Although tusks and horns appear in all cases to have been primarily developed as sexual weapons, they often

serve other purposes. The elephant uses his tusks in attacking the tiger; according to Bruce, he scores the

trunks of trees until they can be thrown down easily, and he likewise thus extracts the farinaceous cores of

palms; in Africa he often uses one tusk, always the same, to probe the ground and thus ascertain whether it

will bear his weight. The common bull defends the herd with his horns; and the elk in Sweden has been

known, according to Lloyd, to strike a wolf dead with a single blow of his great horns. Many similar facts

could be given. One of the most curious secondary uses to which the horns of an animal may be occasionally

put is that observed by Captain Hutton (21. 'Calcutta Journal of Natural History,' vol. ii, 1843, p. 526.) with

the wild goat (Capra aegagrus) of the Himalayas and, as it is also said with the ibex, namely that when the

male accidentally falls from a height he bends inwards his head, and by alighting on his massive horns,

breaks the shock. The female cannot thus use her horns, which are smaller, but from her more quiet

Each male animal uses his weapons in his own peculiar fashion. The common ram makes a charge and butts

with such force with the bases of his horns, that I have seen a powerful man knocked over like a child. Goats

and certain species of sheep, for instance the Ovis cycloceros of Afghanistan (22. Mr. Blyth, in 'Land and

Water,' March, 1867, p. 134, on the authority of Capt. Hutton and others. For the wild Pembrokeshire goats,

see the 'Field,' 1869, p. 150.), rear on their hind legs, and then not only butt, but "make a cut down and a jerk

up, with the ribbed front of their scimitarshaped horn, as with a sabre. When the O. cycloceros attacked a

large domestic ram, who was a noted bruiser, he conquered him by the sheer novelty of his mode of fighting,

always closing at once with his adversary, and catching him across the face and nose with a sharp drawing

jerk of the head, and then bounding out of the way before the blow could be returned." In Pembrokeshire a

male goat, the master of a flock which during several generations had run wild, was known to have killed

several males in single combat; this goat possessed enormous horns, measuring thirtynine inches in a

straight line from tip to tip. The common bull, as every one knows, gores and tosses his opponent; but the

Italian buffalo is said never to use his horns: he gives a tremendous blow with his convex forehead, and then

tramples on his fallen enemy with his kneesan instinct which the common bull does not possess. (23. M.

E.M. Bailly, "Sur l'usage des cornes," etc., .Annal des Sciences Nat.' tom. ii. 1824, p. 369.) Hence a dog who

pins a buffalo by the nose is immediately crushed. We must, however, remember that the Italian buffalo has

been long domesticated, and it is by no means certain that the wild parentform had similar horns. Mr.

Bartlett informs me that when a female Cape buffalo (Bubalus caffer) was turned into an enclosure with a

bull of the same species, she attacked him, and he in return pushed her about with great violence. But it was

manifest to Mr. Bartlett that, had not the bull shewn dignified forbearance, he could easily have killed her by

a single lateral thrust with his immense horns. The giraffe uses his short, haircovered horns, which are rather

longer in the male than in the female, in a curious manner; for, with his long neck, he swings his head to

either side, almost upside down, with such force that I have seen a hard plank deeply indented by a single

With antelopes it is sometimes difficult to imagine how they can possibly use their curiouslyshaped horns;

thus the springboc (Ant. euchore) has rather short upright horns, with the sharp points bent inwards almost at

right angles, so as to face each other; Mr. Bartlett does not know how they are used, but suggests that they

would inflict a fearful wound down each side of the face of an antagonist. The slightlycurved horns of the

Oryx leucoryx (Fig. 63) are directed backwards, and are of such length that their points reach beyond the

middle of the back, over which they extend in almost parallel lines. Thus they seem singularly illfitted for

fighting; but Mr. Bartlett informs me that when two of these animals prepare for battle, they kneel down, with

their beads between their fore legs, and in this attitude the horns stand nearly parallel and close to the ground,

with the points directed forwards and a little upwards. The combatants then gradually approach each other,

and each endeavours to get the upturned points under the body of the other; if one succeeds in doing this, he

suddenly springs up, throwing up his head at the same time, and can thus wound or perhaps even transfix his

antagonist. Both animals always kneel down, so as to guard as far as possible against this manoeuvre. It has

been recorded that one of these antelopes has used his horn with effect even against a lion; yet from being

forced to place his head between the forelegs in order to bring the points of the horns forward, he would

generally be under a great disadvantage when attacked by any other animal. It is, therefore, not probable that

the horns have been modified into their present great length and peculiar position, as a protection against

beasts of prey. We can however see that, as soon as some ancient male progenitor of the Oryx acquired

moderately long horns, directed a little backwards, he would be compelled, in his battles with rival males, to

bend his head somewhat inwards or downwards, as is now done by certain stags; and it is not improbable that

he might have acquired the habit of at first occasionally and afterwards of regularly kneeling down. In this

case it is almost certain that the males which possessed the longest horns would have had a great advantage

over others with shorter horns; and then the horns would gradually have been rendered longer and longer,

through sexual selection, until they acquired their present extraordinary length and position.

With stags of many kinds the branches of the horns offer a curious case of difficulty; for certainly a single

straight point would inflict a much more serious wound than several diverging ones. In Sir Philip Egerton's

museum there is a horn of the reddeer (Cervus elaphus), thirty inches in length, with "not fewer than fifteen

snags or branches"; and at Moritzburg there is still preserved a pair of antlers of a reddeer, shot in 1699 by

Frederick I., one of which bears the astonishing number of thirtythree branches and the other twentyseven,

making altogether sixty branches. Richardson figures a pair of antlers of the wild reindeer with twentynine

points. (24. On the horns of reddeer, Owen, 'British Fossil Mammals,' 1846, p. 478; Richardson on the horns

of the reindeer, 'Fauna Bor. Americana,' 1829, p. 240. I am indebted to Prof. Victor Carus, for the Moritzburg

case.) From the manner in which the horns are branched, and more especially from deer being known

occasionally to fight together by kicking with their fore feet (25. Hon. J.D. Caton ('Ottawa Acad. of Nat.

Science,' May 1868, p. 9) says that the American deer fight with their forefeet, after "the question of

superiority has been once settled and acknowledged in the herd." Bailly, 'Sur l'Usage des cornes,' 'Annales

des Sciences Nat.' tom. ii. 1824, p. 371.), M. Bailly actually comes to the conclusion that their horns are more

injurious than useful to them. But this author overlooks the pitched battles between rival males. As I felt

much perplexed about the use or advantage of the branches, I applied to Mr. McNeill of Colonsay, who has

long and carefully observed the habits of reddeer, and he informs me that he has never seen some of the

branches brought into use, but that the brow antlers, from inclining downwards, are a great protection to the

forehead, and their points are likewise used in attack. Sir Philip Egerton also informs me both as to reddeer

and fallowdeer that, in fighting, they suddenly dash together, and getting their horns fixed against each

other's bodies, a desperate struggle ensues. When one is at last forced to yield and turn round, the victor

endeavours to plunge his brow antlers into his defeated foe. It thus appears that the upper branches are used

chiefly or exclusively for pushing and fencing. Nevertheless in some species the upper branches are used as

weapons of offence; when a man was attacked by a wapiti deer (Cervus canadensis) in Judge Caton's park in

Ottawa, and several men tried to rescue him, the stag "never raised his head from the ground; in fact he kept

his face almost flat on the ground, with his nose nearly between his fore feet, except when he rolled his head

to one side to take a new observation preparatory to a plunge." In this position the ends of the horns were

directed against his adversaries. "In rolling his head he necessarily raised it somewhat, because his antlers

were so long that he could not roll his head without raising them on one side, while, on the other side they

touched the ground." The stag by this procedure gradually drove the party of rescuers backwards to a distance

of 150 or 200 feet; and the attacked man was killed. (26. See a most interesting account in the Appendix to

[Fig. 64. Strepsiceros Kudu (from Sir Andrew Smith's 'Zoology of South Africa.']

Although the horns of stags are efficient weapons, there can, I think be no doubt that a single point would

have been much more dangerous than a branched antler; and Judge Caton, who has had large experience with

deer, fully concurs in this conclusion. Nor do the branching horns, though highly important as a means of

defence against rival stags, appear perfectly well adapted for this purpose, as they are liable to become

interlocked. The suspicion has therefore crossed my mind that they may serve in part as ornaments. That the

branched antlers of stags as well as the elegant lyrated horns of certain antelopes, with their graceful double

curvature (Fig. 64), are ornamental in our eyes, no one will dispute. If, then, the horns, like the splendid

accoutrements of the knights of old, add to the noble appearance of stags and antelopes, they may have been

modified partly for this purpose, though mainly for actual service in battle; but I have no evidence in favour

An interesting case has lately been published, from which it appears that the horns of a deer in one district in

the United States are now being modified through sexual and natural selection. A writer in an excellent

American Journal (27. The 'American Naturalist,' Dec. 1869, p. 552.) says, that he has hunted for the last

twentyone years in the Adirondacks, where the Cervus virginianus abounds. About fourteen years ago he

first heard of SPIKEHORN BUCKS. These became from year to year more common; about five years ago

he shot one, and afterwards another, and now they are frequently killed. "The spikehorn differs greatly from

the common antler of the C. virginianus. It consists of a single spike, more slender than the antler, and

scarcely half so long, projecting forward from the brow, and terminating in a very sharp point. It gives a

considerable advantage to its possessor over the common buck. Besides enabling him to run more swiftly

through the thick woods and underbrush (every hunter knows that does and yearling bucks run much more

rapidly than the large bucks when armed with their cumbrous antlers), the spikehorn is a more effective

weapon than the common antler. With this advantage the spikehorn bucks are gaining upon the common

bucks, and may, in time, entirely supersede them in the Adirondacks. Undoubtedly, the first spikehorn buck

was merely an accidental freak of nature. But his spikehorns gave him an advantage, and enabled him to

propagate his peculiarity. His descendants having a like advantage, have propagated the peculiarity in a

constantly increasing ratio, till they are slowly crowding the antlered deer from the region they inhabit." A

critic has well objected to this account by asking, why, if the simple horns are now so advantageous, were the

branched antlers of the parentform ever developed? To this I can only answer by remarking, that a new

mode of attack with new weapons might be a great advantage, as shewn by the case of the Ovis cycloceros,

who thus conquered a domestic ram famous for his fighting power. Though the branched antlers of a stag are

well adapted for fighting with his rivals, and though it might be an advantage to the pronghorned variety

slowly to acquire long and branched horns, if he had to fight only with others of the same kind, yet it by no

means follows that branched horns would be the best fitted for conquering a foe differently armed. In the

foregoing case of the Oryx leucoryx, it is almost certain that the victory would rest with an antelope having

short horns, and who therefore did not need to kneel down, though an oryx might profit by having still longer

Male quadrupeds, which are furnished with tusks, use them in various ways, as in the case of horns. The boar

strikes laterally and upwards; the musk deer downwards with serious effect. (28. Pallas, 'Spicilegia

Zoologica,' fasc. xiii. 1779, p. 18.) The walrus, though having so short a neck and so unwieldy a body, "can

strike either upwards, or downwards, or sideways, with equal dexterity." (29. Lamont, 'Seasons with the

SeaHorses,' 1861, p. 141.) I was informed by the late Dr. Falconer, that the Indian elephant fights in a

different manner according to the position and curvature of his tusks. When they are directed forwards and

upwards he is able to fling a tiger to a great distanceit is said to even thirty feet; when they are short and

turned downwards he endeavours suddenly to pin the tiger to the ground and, in consequence, is dangerous to

the rider, who is liable to be jerked off the howdah. (30. See also Corse ('Philosophical Transactions,' 1799, p.

212) on the manner in which the shorttusked Mooknah variety attacks other elephants.)

Very few male quadrupeds possess weapons of two distinct kinds specially adapted for fighting with rival

males. The male muntjacdeer (Cervulus), however, offers an exception, as he is provided with horns and

exserted canine teeth. But we may infer from what follows that one form of weapon has often been replaced

in the course of ages by another. With ruminants the development of horns generally stands in an inverse

relation with that of even moderately developed canine teeth. Thus camels, guanacoes, chevrotains, and

muskdeer, are hornless, and they have efficient canines; these teeth being "always of smaller size in the

females than in the males." The Camelidae have, in addition to their true canines, a pair of canineshaped

incisors in their upper jaws. (31. Owen, 'Anatomy of Vertebrates,' vol. iii. p. 349.) Male deer and antelopes,

on the other hand, possess horns, and they rarely have canine teeth; and these, when present, are always of

small size, so that it is doubtful whether they are of any service in their battles. In Antilope montana they

exist only as rudiments in the young male, disappearing as he grows old; and they are absent in the female at

all ages; but the females of certain other antelopes and of certain deer have been known occasionally to

exhibit rudiments of these teeth. (32. See Ruppell (in 'Proc. Zoolog. Soc.' Jan. 12, 1836, p. 3) on the canines

in deer and antelopes, with a note by Mr. Martin on a female American deer. See also Falconer ('Palaeont.

Memoirs and Notes,' vol. i. 1868, p. 576) on canines in an adult female deer. In old males of the muskdeer

the canines (Pallas, 'Spic. Zoolog.' fasc. xiii. 1779, p. 18) sometimes grow to the length of three inches, whilst

in old females a rudiment projects scarcely half an inch above the gums.) Stallions have small canine teeth,

which are either quite absent or rudimentary in the mare; but they do not appear to be used in fighting, for

stallions bite with their incisors, and do not open their mouths wide like camels and guanacoes. Whenever the

adult male possesses canines, now inefficient, whilst the female has either none or mere rudiments, we may

conclude that the early male progenitor of the species was provided with efficient canines, which have been

partially transferred to the females. The reduction of these teeth in the males seems to have followed from

some change in their manner of fighting, often (but not in the horse) caused by the development of new

Tusks and horns are manifestly of high importance to their possessors, for their development consumes much

organised matter. A single tusk of the Asiatic elephantone of the extinct woolly speciesand of the

African elephant, have been known to weigh respectively 150, 160, and 180 pounds; and even greater

weights have been given by some authors. (33. Emerson Tennent, 'Ceylon,' 1859, vol. ii. p. 275; Owen,

'British Fossil Mammals,' 1846, p. 245.) With deer, in which the horns are periodically renewed, the drain on

the constitution must be greater; the horns, for instance, of the moose weigh from fifty to sixty pounds, and

those of the extinct Irish elk from sixty to seventy poundsthe skull of the latter weighing on an average

only five pounds and a quarter. Although the horns are not periodically renewed in sheep, yet their

development, in the opinion of many agriculturists, entails a sensible loss to the breeder. Stags, moreover, in

escaping from beasts of prey are loaded with an additional weight for the race, and are greatly retarded in

passing through a woody country. The moose, for instance, with horns extending five and a half feet from tip

to tip, although so skilful in their use that he will not touch or break a twig when walking quietly, cannot act

so dexterously whilst rushing away from a pack of wolves. "During his progress he holds his nose up, so as to

lay the horns horizontally back; and in this attitude cannot see the ground distinctly." (34. Richardson, 'Fauna

Bor. Americana,' on the moose, Alces palmata, pp. 236, 237; on the expanse of the horns, 'Land and Water,'

1869, p. 143. See also Owen, 'British Fossil Mammals,' on the Irish elk, pp. 447, 455.) The tips of the horns

of the great Irish elk were actually eight feet apart! Whilst the horns are covered with velvet, which lasts with

reddeer for about twelve weeks, they are extremely sensitive to a blow; so that in Germany the stags at this

time somewhat change their habits, and avoiding dense forests, frequent young woods and low thickets. (35.

'Forest Creatures,' by C. Boner, 1861, p. 60.) These facts remind us that male birds have acquired ornamental

plumes at the cost of retarded flight, and other ornaments at the cost of some loss of power in their battles

With mammals, when, as is often the case, the sexes differ in size, the males are almost always larger and

stronger. I am informed by Mr. Gould that this holds good in a marked manner with the marsupials of

Australia, the males of which appear to continue growing until an unusually late age. But the most

extraordinary case is that of one of the seals (Callorhinus ursinus), a fullgrown female weighing less than

onesixth of a fullgrown male. (36. See the very interesting paper by Mr. J.A. Allen in 'Bull. Mus. Comp.

Zoology of Cambridge, United States,' vol. ii. No. 1, p. 82. The weights were ascertained by a careful

observer, Capt. Bryant. Dr. Gill in 'The American Naturalist,' January, 1871, Prof. Shaler on the relative size

of the sexes of whales, 'American Naturalist,' January, 1873.) Dr. Gill remarks that it is with the polygamous

seals, the males of which are well known to fight savagely together, that the sexes differ much in size; the

monogamous species differing but little. Whales also afford evidence of the relation existing between the

pugnacity of the males and their large size compared with that of the female; the males of the rightwhales

do not fight together, and they are not larger, but rather smaller, than their females; on the other hand, male

spermwhales fight much together, and their bodies are "often found scarred with the imprint of their rival's

teeth," and they are double the size of the females. The greater strength of the male, as Hunter long ago

remarked (37. 'Animal Economy,' p. 45.), is invariably displayed in those parts of the body which are brought

into action in fighting with rival malesfor instance, in the massive neck of the bull. Male quadrupeds are

also more courageous and pugnacious than the females. There can be little doubt that these characters have

been gained, partly through sexual selection, owing to a long series of victories, by the stronger and more

courageous males over the weaker, and partly through the inherited effects of use. It is probable that the

successive variations in strength, size, and courage, whether due to mere variability or to the effects of use,

by the accumulation of which male quadrupeds have acquired these characteristic qualities, occurred rather

late in life, and were consequently to a large extent limited in their transmission to the same sex.

From these considerations I was anxious to obtain information as to the Scotch deerhound, the sexes of

which differ more in size than those of any other breed (though bloodhounds differ considerably), or than in

any wild canine species known to me. Accordingly, I applied to Mr. Cupples, well known for his success

with this breed, who has weighed and measured many of his own dogs, and who has with great kindness

collected for me the following facts from various sources. Fine male dogs, measured at the shoulder, range

from 28 inches, which is low, to 33 or even 34 inches in height; and in weight from 80 pounds, which is light,

to 120 pounds, or even more. The females range in height from 23 to 27, or even to 28 inches; and in weight

from 50 to 70, or even 80 pounds. (38. See also Richardson's 'Manual on the Dog,' p. 59. Much valuable

information on the Scottish deerhound is given by Mr. McNeill, who first called attention to the inequality

in size between the sexes, in Scrope's 'Art of Deer Stalking.' I hope that Mr. Cupples will keep to his

intention of publishing a full account and history of this famous breed.) Mr. Cupples concludes that from 95

to 100 pounds for the male, and 70 for the female, would be a safe average; but there is reason to believe that

formerly both sexes attained a greater weight. Mr. Cupples has weighed puppies when a fortnight old; in one

litter the average weight of four males exceeded that of two females by six and a half ounces; in another litter

the average weight of four males exceeded that of one female by less than one ounce; the same males when

three weeks old, exceeded the female by seven and a half ounces, and at the age of six weeks by nearly

fourteen ounces. Mr. Wright of Yeldersley House, in a letter to Mr. Cupples, says: "I have taken notes on the

sizes and weights of puppies of many litters, and as far as my experience goes, dogpuppies as a rule differ

very little from bitches till they arrive at about five or six months old; and then the dogs begin to increase,

gaining upon the bitches both in weight and size. At birth, and for several weeks afterwards, a bitchpuppy

will occasionally be larger than any of the dogs, but they are invariably beaten by them later." Mr. McNeill,

of Colonsay, concludes that "the males do not attain their full growth till over two years old, though the

females attain it sooner." According to Mr. Cupples' experience, male dogs go on growing in stature till they

are from twelve to eighteen months old, and in weight till from eighteen to twentyfour months old; whilst

the females cease increasing in stature at the age of from nine to fourteen or fifteen months, and in weight at

the age of from twelve to fifteen months. From these various statements it is clear that the full difference in

size between the male and female Scotch deerhound is not acquired until rather late in life. The males

almost exclusively are used for coursing, for, as Mr. McNeill informs me, the females have not sufficient

strength and weight to pull down a fullgrown deer. From the names used in old legends, it appears, as I hear

from Mr. Cupples, that, at a very ancient period, the males were the most celebrated, the females being

mentioned only as the mothers of famous dogs. Hence, during many generations, it is the male which has

been chiefly tested for strength, size, speed, and courage, and the best will have been bred from. As, however,

the males do not attain their full dimensions until rather late in life, they will have tended, in accordance with

the law often indicated, to transmit their characters to their male offspring alone; and thus the great inequality

in size between the sexes of the Scotch deerhound may probably be accounted for.

The males of some few quadrupeds possess organs or parts developed solely as a means of defence against

the attacks of other males. Some kinds of deer use, as we have seen, the upper branches of their horns chiefly

or exclusively for defending themselves; and the Oryx antelope, as I am informed by Mr. Bartlett, fences

most skilfully with his long, gently curved horns; but these are likewise used as organs of offence. The same

observer remarks that rhinoceroses in fighting, parry each other's sidelong blows with their horns, which

clatter loudly together, as do the tusks of boars. Although wild boars fight desperately, they seldom,

according to Brehm, receive fatal wounds, as the blows fall on each other's tusks, or on the layer of gristly

skin covering the shoulder, called by the German hunters, the shield; and here we have a part specially

modified for defence. With boars in the prime of life (Fig. 65) the tusks in the lower jaw are used for fighting,

but they become in old age, as Brehm states, so much curved inwards and upwards over the snout that they

can no longer be used in this way. They may, however, still serve, and even more effectively, as a means of

defence. In compensation for the loss of the lower tusks as weapons of offence, those in the upper jaw, which

always project a little laterally, increase in old age so much in length and curve so much upwards that they

can be used for attack. Nevertheless, an old boar is not so dangerous to man as one at the age of six or seven

In the fullgrown male Babirusa pig of Celebes (Fig. 66), the lower tusks are formidable weapons, like those

of the European boar in the prime of life, whilst the upper tusks are so long and have their points so much

curled inwards, sometimes even touching the forehead, that they are utterly useless as weapons of attack.

They more nearly resemble horns than teeth, and are so manifestly useless as teeth that the animal was

formerly supposed to rest his head by hooking them on to a branch! Their convex surfaces, however, if the

head were held a little laterally, would serve as an excellent guard; and hence, perhaps, it is that in old

animals they "are generally broken off, as if by fighting." (40. See Mr. Wallace's interesting account of this

animal, 'The Malay Archipelago,' 1869, vol. i. p. 435.) Here, then, we have the curious case of the upper tusks

of the Babirusa regularly assuming during the prime of life a structure which apparently renders them fitted

only for defence; whilst in the European boar the lower tusks assume in a less degree and only during old age

[Fig. 67. Head of female Aethopian warthog, from 'Proc. Zool. Soc.' 1869, shewing the same characters as

the male, though on a reduced scale. N.B. When the engraving was first made, I was under the impression

In the warthog (see Phacochoerus aethiopicus, Fig. 67) the tusks in the upper jaw of the male curve upwards

during the prime of life, and from being pointed serve as formidable weapons. The tusks in the lower jaw are

sharper than those in the upper, but from their shortness it seems hardly possible that they can be used as

weapons of attack. They must, however, greatly strengthen those in the upper jaw, from being ground so as to

fit closely against their bases. Neither the upper nor the lower tusks appear to have been specially modified to

act as guards, though no doubt they are to a certain extent used for this purpose. But the warthog is not

destitute of other special means of protection, for it has, on each side of the face, beneath the eyes, a rather

stiff, yet flexible, cartilaginous, oblong pad (Fig. 67), which projects two or three inches outwards; and it

appeared to Mr. Bartlett and myself, when viewing the living animal, that these pads, when struck from

beneath by the tusks of an opponent, would be turned upwards, and would thus admirably protect the

somewhat prominent eyes. I may add, on the authority of Mr. Bartlett, that these boars when fighting stand

Lastly, the African riverhog (Potomochoerus penicillatus) has a hard cartilaginous knob on each side of the

face beneath the eyes, which answers to the flexible pad of the warthog; it has also two bony prominences

on the upper jaw above the nostrils. A boar of this species in the Zoological Gardens recently broke into the

cage of the warthog. They fought all night long, and were found in the morning much exhausted, but not

seriously wounded. It is a significant fact, as shewing the purposes of the above described projections and

excrescences, that these were covered with blood, and were scored and abraded in an extraordinary manner.

Although the males of so many members of the pig family are provided with weapons, and as we have just

seen with means of defence, these weapons seem to have been acquired within a rather late geological period.

Dr. Forsyth Major specifies (41. 'Atti della Soc. Italiana di Sc. Nat.' 1873, vol. xv. fasc. iv.) several miocene

species, in none of which do the tusks appear to have been largely developed in the males; and Professor

The mane of the lion forms a good defence against the attacks of rival lions, the one danger to which he is

liable; for the males, as Sir A. Smith informs me, engage in terrible battles, and a young lion dares not

approach an old one. In 1857 a tiger at Bromwich broke into the cage of a lion and a fearful scene ensued:

"the lion's mane saved his neck and head from being much injured, but the tiger at last succeeded in ripping

up his belly, and in a few minutes he was dead." (42. 'The Times,' Nov. 10, 1857. In regard to the Canada

lynx, see Audubon and Bachman, 'Quadrupeds of North America,' 1846, p. 139.) The broad ruff round the

throat and chin of the Canadian lynx (Felis canadensis) is much longer in the male than in the female; but

whether it serves as a defence I do not know. Male seals are well known to fight desperately together, and the

males of certain kinds (Otaria jubata) (43. Dr. Murie, on Otaria, 'Proc. Zoolog. Soc.' 1869, p. 109. Mr. J.A.

Allen, in the paper above quoted (p. 75), doubts whether the hair, which is longer on the neck in the male

than in the female, deserves to be called a mane.) have great manes, whilst the females have small ones or

none. The male baboon of the Cape of Good Hope (Cynocephalus porcarius) has a much longer mane and

larger canine teeth than the female; and the mane probably serves as a protection, for, on asking the keepers

in the Zoological Gardens, without giving them any clue to my object, whether any of the monkeys especially

attacked each other by the nape of the neck, I was answered that this was not the case, except with the above

baboon. In the Hamadryas baboon, Ehrenberg compares the mane of the adult male to that of a young lion,

It appeared to me probable that the immense woolly mane of the male American bison, which reaches almost

to the ground, and is much more developed in the males than in the females, served as a protection to them in

their terrible battles; but an experienced hunter told Judge Caton that he had never observed anything which

favoured this belief. The stallion has a thicker and fuller mane than the mare; and I have made particular

inquiries of two great trainers and breeders, who have had charge of many entire horses, and am assured that

they "invariably endeavour to seize one another by the neck." It does not, however, follow from the foregoing

statements, that when the hair on the neck serves as a defence, that it was originally developed for this

purpose, though this is probable in some cases, as in that of the lion. I am informed by Mr. McNeill that the

long hairs on the throat of the stag (Cervus elaphus) serve as a great protection to him when hunted, for the

dogs generally endeavour to seize him by the throat; but it is not probable that these hairs were specially

developed for this purpose; otherwise the young and the females would have been equally protected.

Before describing in the next chapter, the differences between the sexes in voice, odours emitted, and

ornaments, it will be convenient here to consider whether the sexes exert any choice in their unions. Does the

female prefer any particular male, either before or after the males may have fought together for supremacy; or

does the male, when not a polygamist, select any particular female? The general impression amongst breeders

seems to be that the male accepts any female; and this owing to his eagerness, is, in most cases, probably the

truth. Whether the female as a general rule indifferently accepts any male is much more doubtful. In the

fourteenth chapter, on Birds, a considerable body of direct and indirect evidence was advanced, shewing that

the female selects her partner; and it would be a strange anomaly if female quadrupeds, which stand higher in

the scale and have higher mental powers, did not generally, or at least often, exert some choice. The female

could in most cases escape, if wooed by a male that did not please or excite her; and when pursued by several

males, as commonly occurs, she would often have the opportunity, whilst they were fighting together, of

escaping with some one male, or at least of temporarily pairing with him. This latter contingency has often

been observed in Scotland with female reddeer, as I am informed by Sir Philip Egerton and others. (44. Mr.

Boner, in his excellent description of the habits of the reddeer in Germany ('Forest Creatures,' 1861, p. 81)

says, "while the stag is defending his rights against one intruder, another invades the sanctuary of his harem,

and carries off trophy after trophy." Exactly the same thing occurs with seals; see Mr. J.A. Allen, ibid. p.

It is scarcely possible that much should be known about female quadrupeds in a state of nature making any

choice in their marriage unions. The following curious details on the courtship of one of the eared seals

(Callorhinus ursinus) are given (45. Mr. J.A. Allen in 'Bull. Mus. Comp. Zoolog. of Cambridge, United

States,' vol. ii. No. 1, p. 99.) on the authority of Capt. Bryant, who had ample opportunities for observation.

He says, "Many of the females on their arrival at the island where they breed appear desirous of returning to

some particular male, and frequently climb the outlying rocks to overlook the rookeries, calling out and

listening as if for a familiar voice. Then changing to another place they do the same again...As soon as a

female reaches the shore, the nearest male goes down to meet her, making meanwhile a noise like the

clucking of a hen to her chickens. He bows to her and coaxes her until he gets between her and the water so

that she cannot escape him. Then his manner changes, and with a harsh growl he drives her to a place in his

harem. This continues until the lower row of harems is nearly full. Then the males higher up select the time

when their more fortunate neighbours are off their guard to steal their wives. This they do by taking them in

their mouths and lifting them over the heads of the other females, and carefully placing them in their own

harem, carrying them as cats do their kittens. Those still higher up pursue the same method until the whole

space is occupied. Frequently a struggle ensues between two males for the possession of the same female, and

both seizing her at once pull her in two or terribly lacerate her with their teeth. When the space is all filled,

the old male walks around complacently reviewing his family, scolding those who crowd or disturb the

others, and fiercely driving off all intruders. This surveillance always keeps him actively occupied."

As so little is known about the courtship of animals in a state of nature, I have endeavoured to discover how

far our domesticated quadrupeds evince any choice in their unions. Dogs offer the best opportunity for

observation, as they are carefully attended to and well understood. Many breeders have expressed a strong

opinion on this head. Thus, Mr. Mayhew remarks, "The females are able to bestow their affections; and

tender recollections are as potent over them as they are known to be in other cases, where higher animals are

concerned. Bitches are not always prudent in their loves, but are apt to fling themselves away on curs of low

degree. If reared with a companion of vulgar appearance, there often springs up between the pair a devotion

which no time can afterwards subdue. The passion, for such it really is, becomes of a more than romantic

endurance." Mr. Mayhew, who attended chiefly to the smaller breeds, is convinced that the females are

strongly attracted by males of a large size. (46. 'Dogs: their Management,' by E. Mayhew, M.R.C.V.S., 2nd

ed., 1864, pp. 187192.) The wellknown veterinary Blaine states (47. Quoted by Alex. Walker, 'On

Intermarriage,' 1838, p. 276; see also p. 244.) that his own female pug dog became so attached to a spaniel,

and a female setter to a cur, that in neither case would they pair with a dog of their own breed until several

weeks had elapsed. Two similar and trustworthy accounts have been given me in regard to a female retriever

Mr. Cupples informs me that he can personally vouch for the accuracy of the following more remarkable

case, in which a valuable and wonderfully intelligent female terrier loved a retriever belonging to a

neighbour to such a degree, that she had often to be dragged away from him. After their permanent

separation, although repeatedly shewing milk in her teats, she would never acknowledge the courtship of any

other dog, and to the regret of her owner never bore puppies. Mr. Cupples also states, that in 1868, a female

deerhound in his kennel thrice produced puppies, and on each occasion shewed a marked preference for one

of the largest and handsomest, but not the most eager, of four deerhounds living with her, all in the prime of

life. Mr. Cupples has observed that the female generally favours a dog whom she has associated with and

knows; her shyness and timidity at first incline her against a strange dog. The male, on the contrary, seems

rather inclined towards strange females. It appears to be rare when the male refuses any particular female, but

Mr. Wright, of Yeldersley House, a great breeder of dogs, informs me that he has known some instances; he

cites the case of one of his own deerhounds, who would not take any notice of a particular female mastiff, so

that another deerhound had to be employed. It would be superfluous to give, as I could, other instances, and I

will only add that Mr. Barr, who has carefully bred many bloodhounds, states that in almost every instance

particular individuals of opposite sexes shew a decided preference for each other. Finally, Mr. Cupples, after

attending to this subject for another year, has written to me, "I have had full confirmation of my former

statement, that dogs in breeding form decided preferences for each other, being often influenced by size,

bright colour, and individual characters, as well as by the degree of their previous familiarity."

In regard to horses, Mr. Blenkiron, the greatest breeder of racehorses in the world, informs me that stallions

are so frequently capricious in their choice, rejecting one mare and without any apparent cause taking to

another, that various artifices have to be habitually used. The famous Monarque, for instance, would never

consciously look at the dam of Gladiateur, and a trick had to be practised. We can partly see the reason why

valuable racehorse stallions, which are in such demand as to be exhausted, should be so particular in their

choice. Mr. Blenkiron has never known a mare reject a horse; but this has occurred in Mr. Wright's stable, so

that the mare had to be cheated. Prosper Lucas (48. 'Traite de l'Hered. Nat.' tom. ii. 1850, p. 296.) quotes

various statements from French authorities, and remarks, "On voit des etalons qui s'eprennent d'une jument,

et negligent toutes les autres." He gives, on the authority of Baelen, similar facts in regard to bulls; and Mr.

H. Reeks assures me that a famous shorthorn bull belonging to his father "invariably refused to be matched

with a black cow." Hoffberg, in describing the domesticated reindeer of Lapland says, "Foeminae majores et

fortiores mares prae caeteris admittunt, ad eos confugiunt, a junioribus agitatae, qui hos in fugam conjiciunt."

(49. 'Amoenitates Acad.' vol. iv. 1788, p. 160.) A clergyman, who has bred many pigs, asserts that sows often

From these facts there can be no doubt that, with most of our domesticated quadrupeds, strong individual

antipathies and preferences are frequently exhibited, and much more commonly by the female than by the

male. This being the case, it is improbable that the unions of quadrupeds in a state of nature should be left to

mere chance. It is much more probable that the females are allured or excited by particular males, who

possess certain characters in a higher degree than other males; but what these characters are, we can seldom

VoiceRemarkable sexual peculiarities in sealsOdourDevelopment of the hairColour of the hair

and skinAnomalous case of the female being more ornamented than the maleColour and ornaments due

to sexual selection Colour acquired for the sake of protectionColour, though common to both sexes,

often due to sexual selectionOn the disappearance of spots and stripes in adult quadrupedsOn the

Quadrupeds use their voices for various purposes, as a signal of danger, as a call from one member of a troop

to another, or from the mother to her lost offspring, or from the latter for protection to their mother; but such

uses need not here be considered. We are concerned only with the difference between the voices of the sexes,

for instance between that of the lion and lioness, or of the bull and cow. Almost all male animals use their

voices much more during the ruttingseason than at any other time; and some, as the giraffe and porcupine

(1. Owen, 'Anatomy of Vertebrates,' vol. iii. p. 585.), are said to be completely mute excepting at this season.

As the throats (i.e. the larynx and thyroid bodies (2. Ibid. p. 595.)) of stags periodically become enlarged at

the beginning of the breedingseason, it might be thought that their powerful voices must be somehow of

high importance to them; but this is very doubtful. From information given to me by two experienced

observers, Mr. McNeill and Sir P. Egerton, it seems that young stags under three years old do not roar or

bellow; and that the old ones begin bellowing at the commencement of the breedingseason, at first only

occasionally and moderately, whilst they restlessly wander about in search of the females. Their battles are

prefaced by loud and prolonged bellowing, but during the actual conflict they are silent. Animals of all kinds

which habitually use their voices utter various noises under any strong emotion, as when enraged and

preparing to fight; but this may merely be the result of nervous excitement, which leads to the spasmodic

contraction of almost all the muscles of the body, as when a man grinds his teeth and clenches his fists in rage

or agony. No doubt stags challenge each other to mortal combat by bellowing; but those with the more

powerful voices, unless at the same time the stronger, betterarmed, and more courageous, would not gain

It is possible that the roaring of the lion may be of some service to him by striking terror into his adversary;

for when enraged he likewise erects his mane and thus instinctively tries to make himself appear as terrible as

possible. But it can hardly be supposed that the bellowing of the stag, even if it be of service to him in this

way, can have been important enough to have led to the periodical enlargement of the throat. Some writers

suggest that the bellowing serves as a call to the female; but the experienced observers above quoted inform

me that female deer do not search for the male, though the males search eagerly for the females, as indeed

might be expected from what we know of the habits of other male quadrupeds. The voice of the female, on

the other hand, quickly brings to her one or more stags (3. See, for instance, Major W. Ross King ('The

Sportsman in Canada,' 1866, pp. 53, 131) on the habits of the moose and wild reindeer.), as is well known to

the hunters who in wild countries imitate her cry. If we could believe that the male had the power to excite or

allure the female by his voice, the periodical enlargement of his vocal organs would be intelligible on the

principle of sexual selection, together with inheritance limited to the same sex and season; but we have no

evidence in favour of this view. As the case stands, the loud voice of the stag during the breedingseason

does not seem to be of any special service to him, either during his courtship or battles, or in any other way.

But may we not believe that the frequent use of the voice, under the strong excitement of love, jealousy, and

rage, continued during many generations, may at last have produced an inherited effect on the vocal organs of

the stag, as well as of other male animals? This appears to me, in our present state of knowledge, the most

The voice of the adult male gorilla is tremendous, and he is furnished with a laryngeal sack, as is the adult

male orang. (4. Owen 'Anatomy of Vertebrates,' vol. iii. p. 600.) The gibbons rank among the noisiest of

monkeys, and the Sumatra species (Hylobates syndactylus) is also furnished with an air sack; but Mr. Blyth,

who has had opportunities for observation, does not believe that the male is noisier than the female. Hence,

these latter monkeys probably use their voices as a mutual call; and this is certainly the case with some

quadrupeds, for instance the beaver. (5. Mr. Green, in 'Journal of Linnean Society,' vol. x. 'Zoology,' 1869,

note 362.) Another gibbon, the H. agilis, is remarkable, from having the power of giving a complete and

correct octave of musical notes (6. C.L. Martin, 'General Introduction to the Natural History of Mamm.

Animals,' 1841, p. 431.), which we may reasonably suspect serves as a sexual charm; but I shall have to recur

to this subject in the next chapter. The vocal organs of the American Mycetes caraya are onethird larger in

the male than in the female, and are wonderfully powerful. These monkeys in warm weather make the forests

resound at morning and evening with their overwhelming voices. The males begin the dreadful concert, and

often continue it during many hours, the females sometimes joining in with their less powerful voices. An

excellent observer, Rengger (7. 'Naturgeschichte der Saugethiere von Paraguay,' 1830, ss. 15, 21.), could not

perceive that they were excited to begin by any special cause; he thinks that, like many birds, they delight in

their own music, and try to excel each other. Whether most of the foregoing monkeys have acquired their

powerful voices in order to beat their rivals and charm the femalesor whether the vocal organs have been

strengthened and enlarged through the inherited effects of longcontinued use without any particular good

being thus gainedI will not pretend to say; but the former view, at least in the case of the Hylobates agilis,

I may here mention two very curious sexual peculiarities occurring in seals, because they have been supposed

by some writers to affect the voice. The nose of the male seaelephant (Macrorhinus proboscideus) becomes

greatly elongated during the breedingseason, and can then be erected. In this state it is sometimes a foot in

length. The female is not thus provided at any period of life. The male makes a wild, hoarse, gurgling noise,

which is audible at a great distance and is believed to be strengthened by the proboscis; the voice of the

female being different. Lesson compares the erection of the proboscis, with the swelling of the wattles of

male gallinaceous birds whilst courting the females. In another allied kind of seal, the bladdernose

(Cystophora cristata), the head is covered by a great hood or bladder. This is supported by the septum of the

nose, which is produced far backwards and rises into an internal crest seven inches in height. The hood is

clothed with short hair, and is muscular; can be inflated until it more than equals the whole head in size! The

males when rutting, fight furiously on the ice, and their roaring "is said to be sometimes so loud as to be

heard four miles off." When attacked they likewise roar or bellow; and whenever irritated the bladder is

inflated and quivers. Some naturalists believe that the voice is thus strengthened, but various other uses have

been assigned to this extraordinary structure. Mr. R. Brown thinks that it serves as a protection against

accidents of all kinds; but this is not probable, for, as I am assured by Mr. Lamont who killed 600 of these

animals, the hood is rudimentary in the females, and it is not developed in the males during youth. (8. On the

seaelephant, see an article by Lesson, in 'Dict. Class. Hist. Nat.' tom. xiii. p. 418. For the Cystophora, or

Stemmatopus, see Dr. Dekay, 'Annals of Lyceum of Nat. Hist.' New York, vol. i. 1824, p. 94. Pennant has

also collected information from the sealers on this animal. The fullest account is given by Mr. Brown, in

With some animals, as with the notorious skunk of America, the overwhelming odour which they emit

appears to serve exclusively as a defence. With shrewmice (Sorex) both sexes possess abdominal

scentglands, and there can be little doubt, from the rejection of their bodies by birds and beasts of prey, that

the odour is protective; nevertheless, the glands become enlarged in the males during the breedingseason. In

many other quadrupeds the glands are of the same size in both sexes (9. As with the castoreum of the beaver,

see Mr. L.H. Morgan's most interesting work, 'The American Beaver,' 1868, p. 300. Pallas ('Spic. Zoolog.'

fasc. viii. 1779, p. 23) has well discussed the odoriferous glands of mammals. Owen ('Anat. of Vertebrates,'

vol. iii. p. 634) also gives an account of these glands, including those of the elephant, and (p. 763) those of

shrewmice. On bats, Mr. Dobson in 'Proceedings of the Zoological Society' 1873, p. 241.), but their uses are

not known. In other species the glands are confined to the males, or are more developed than in the females;

and they almost always become more active during the ruttingseason. At this period the glands on the sides

of the face of the male elephant enlarge, and emit a secretion having a strong musky odour. The males, and

rarely the females, of many kinds of bats have glands and protrudable sacks situated in various parts; and it is

The rank effluvium of the male goat is well known, and that of certain male deer is wonderfully strong and

persistent. On the banks of the Plata I perceived the air tainted with the odour of the male Cervus campestris,

at half a mile to leeward of a herd; and a silk handkerchief, in which I carried home a skin, though often used

and washed, retained, when first unfolded, traces of the odour for one year and seven months. This animal

does not emit its strong odour until more than a year old, and if castrated whilst young never emits it. (10.

Rengger, 'Naturgeschichte der Saugethiere von Paraguay,' 1830, s. 355. This observer also gives some

curious particulars in regard to the odour.) Besides the general odour, permeating the whole body of certain

ruminants (for instance, Bos moschatus) in the breedingseason, many deer, antelopes, sheep, and goats

possess odoriferous glands in various situations, more especially on their faces. The socalled tearsacks, or

suborbital pits, come under this head. These glands secrete a semifluid fetid matter which is sometimes so

copious as to stain the whole face, as I have myself seen in an antelope. They are "usually larger in the male

than in the female, and their development is checked by castration." (11. Owen, 'Anatomy of Vertebrates,'

vol. iii. p. 632. See also Dr. Murie's observations on those glands in the 'Proc. Zoolog. Soc.' 1870, p. 340.

Desmarest, 'On the Antilope subgutturosa, 'Mammalogie,' 1820, p. 455.) According to Desmarest they are

altogether absent in the female of Antilope subgutturosa. Hence, there can be no doubt that they stand in

close relation with the reproductive functions. They are also sometimes present, and sometimes absent, in

nearly allied forms. In the adult male muskdeer (Moschus moschiferus), a naked space round the tail is

bedewed with an odoriferous fluid, whilst in the adult female, and in the male until two years old, this space

is covered with hair and is not odoriferous. The proper musk sack of this deer is from its position

necessarily confined to the male, and forms an additional scentorgan. It is a singular fact that the matter

secreted by this latter gland, does not, according to Pallas, change in consistence, or increase in quantity,

during the ruttingseason; nevertheless this naturalist admits that its presence is in some way connected with

the act of reproduction. He gives, however, only a conjectural and unsatisfactory explanation of its use. (12.

Pallas, 'Spicilegia Zoolog.' fasc. xiii. 1799, p. 24; Desmoulins, 'Dict. Class. d'Hist. Nat.' tom. iii. p. 586.)

In most cases, when only the male emits a strong odour during the breeding season, it probably serves to

excite or allure the female. We must not judge on this head by our own taste, for it is well known that rats are

enticed by certain essential oils, and cats by valerian, substances far from agreeable to us; and that dogs,

though they will not eat carrion, sniff and roll on it. From the reasons given when discussing the voice of the

stag, we may reject the idea that the odour serves to bring the females from a distance to the males. Active

and longcontinued use cannot here have come into play, as in the case of the vocal organs. The odour

emitted must be of considerable importance to the male, inasmuch as large and complex glands, furnished

with muscles for everting the sack, and for closing or opening the orifice, have in some cases been developed.

The development of these organs is intelligible through sexual selection, if the most odoriferous males are the

most successful in winning the females, and in leaving offspring to inherit their gradually perfected glands

We have seen that male quadrupeds often have the hair on their necks and shoulders much more developed

than the females; and many additional instances could be given. This sometimes serves as a defence to the

male during his battles; but whether the hair in most cases has been specially developed for this purpose, is

very doubtful. We may feel almost certain that this is not the case, when only a thin and narrow crest runs

along the back; for a crest of this kind would afford scarcely any protection, and the ridge of the back is not a

place likely to be injured; nevertheless such crests are sometimes confined to the males, or are much more

developed in them than in the females. Two antelopes, the Tragelaphus scriptus (13. Dr. Gray, 'Gleanings

from the Menagerie at Knowsley,' pl. 28.) (Fig. 70) and Portax picta may be given as instances. When stags,

and the males of the wild goat, are enraged or terrified, these crests stand erect (14. Judge Caton on the

Wapiti, 'Transact. Ottawa Acad. Nat. Sciences,' 1868, pp. 36, 40; Blyth, 'Land and Water,' on Capra aegagrus

1867, p. 37.); but it cannot be supposed that they have been developed merely for the sake of exciting fear in

their enemies. One of the abovenamed antelopes, the Portax picta, has a large welldefined brush of black

hair on the throat, and this is much larger in the male than in the female. In the Ammotragus tragelaphus of

North Africa, a member of the sheepfamily, the forelegs are almost concealed by an extraordinary growth

of hair, which depends from the neck and upper halves of the legs; but Mr. Bartlett does not believe that this

mantle is of the least use to the male, in whom it is much more developed than in the female.

Male quadrupeds of many kinds differ from the females in having more hair, or hair of a different character,

on certain parts of their faces. Thus the bull alone has curled hair on the forehead. (15. Hunter's 'Essays and

Observations,' edited by Owen, 1861. vol. i. p. 236.) In three closely allied subgenera of the goat family,

only the males possess beards, sometimes of large size; in two other subgenera both sexes have a beard, but

it disappears in some of the domestic breeds of the common goat; and neither sex of the Hemitragus has a

beard. In the ibex the beard is not developed during the summer, and is so small at other times that it may be

called rudimentary. (16. See Dr. Gray's 'Catalogue of Mammalia in the British Museum,' part iii. 1852, p.

144.) With some monkeys the beard is confined to the male, as in the orang; or is much larger in the male

than in the female, as in the Mycetes caraya and Pithecia satanas (Fig. 68). So it is with the whiskers of some

species of Macacus (17. Rengger, 'Saugthiere,' etc., s. 14; Desmarest, 'Mammalogie,' p. 86.), and, as we have

seen, with the manes of some species of baboons. But with most kinds of monkeys the various tufts of hair

The males of various members of the ox family (Bovidae), and of certain antelopes, are furnished with a

dewlap, or great fold of skin on the neck, which is much less developed in the female.

Now, what must we conclude with respect to such sexual differences as these? No one will pretend that the

beards of certain male goats, or the dewlaps of the bull, or the crests of hair along the backs of certain male

antelopes, are of any use to them in their ordinary habits. It is possible that the immense beard of the male

Pithecia, and the large beard of the male orang, may protect their throats when fighting; for the keepers in the

Zoological Gardens inform me that many monkeys attack each other by the throat; but it is not probable that

the beard has been developed for a distinct purpose from that served by the whiskers, moustache, and other

tufts of hair on the face; and no one will suppose that these are useful as a protection. Must we attribute all

these appendages of hair or skin to mere purposeless variability in the male? It cannot be denied that this is

possible; for in many domesticated quadrupeds, certain characters, apparently not derived through reversion

from any wild parent form, are confined to the males, or are more developed in them than in the females

for instance, the hump on the male zebucattle of India, the tail of fat tailed rams, the arched outline of the

forehead in the males of several breeds of sheep, and lastly, the mane, the long hairs on the hind legs, and the

dewlap of the male of the Berbura goat. (18. See the chapters on these several animals in vol. i. of my

'Variation of Animals under Domestication;' also vol. ii. p. 73; also chap. xx. on the practice of selection by

semicivilised people. For the Berbura goat, see Dr. Gray, 'Catalogue,' ibid. p. 157.) The mane, which occurs

only in the rams of an African breed of sheep, is a true secondary sexual character, for, as I hear from Mr.

Winwood Reade, it is not developed if the animal be castrated. Although we ought to be extremely cautious,

as shewn in my work on 'Variation under Domestication,' in concluding that any character, even with animals

kept by semicivilised people, has not been subjected to selection by man, and thus augmented, yet in the

cases just specified this is improbable; more especially as the characters are confined to the males, or are

more strongly developed in them than in the females. If it were positively known that the above African ram

is a descendant of the same primitive stock as the other breeds of sheep, and if the Berbura malegoat with

his mane, dewlap, etc., is descended from the same stock as other goats, then, assuming that selection has not

been applied to these characters, they must be due to simple variability, together with sexually limited

Hence it appears reasonable to extend this same view to all analogous cases with animals in a state of nature.

Nevertheless I cannot persuade myself that it generally holds good, as in the case of the extraordinary

development of hair on the throat and forelegs of the male Ammotragus, or in that of the immense beard of

the male Pithecia. Such study as I have been able to give to nature makes me believe that parts or organs

which are highly developed, were acquired at some period for a special purpose. With those antelopes in

which the adult male is more stronglycoloured than the female, and with those monkeys in which the hair

on the face is elegantly arranged and coloured in a diversified manner, it seems probable that the crests and

tufts of hair were gained as ornaments; and this I know is the opinion of some naturalists. If this be correct,

there can be little doubt that they were gained or at least modified through sexual selection; but how far the

I will first give briefly all the cases known to me of male quadrupeds differing in colour from the females.

With Marsupials, as I am informed by Mr. Gould, the sexes rarely differ in this respect; but the great red

kangaroo offers a striking exception, "delicate blue being the prevailing tint in those parts of the female

which in the male are red." (19. Osphranter rufus, Gould, 'Mammals of Australia,' 1863, vol. ii. On the

Didelphis, Desmarest, 'Mammalogie,' p. 256.) In the Didelphis opossum of Cayenne the female is said to be a

little more red than the male. Of the Rodents, Dr. Gray remarks: "African squirrels, especially those found in

the tropical regions, have the fur much brighter and more vivid at some seasons of the year than at others, and

the fur of the male is generally brighter than that of the female." (20. 'Annals and Magazine of Natural

History,' Nov. 1867, p. 325. On the Mus minutus, Desmarest, 'Mammalogie,' p. 304.) Dr. Gray informs me

that he specified the African squirrels, because, from their unusually bright colours, they best exhibit this

difference. The female of the Mus minutus of Russia is of a paler and dirtier tint than the male. In a large

number of bats the fur of the male is lighter than in the female. (21. J.A. Allen, in 'Bulletin of Mus. Comp.

Zoolog. of Cambridge, United States,' 1869, p. 207. Mr. Dobson on sexual characters in the Chiroptera,

'Proceedings of the Zoological Society,' 1873, p. 241. Dr. Gray on Sloths, ibid. 1871, p. 436.) Mr. Dobson

also remarks, with respect to these animals: "Differences, depending partly or entirely on the possession by

the male of fur of a much more brilliant hue, or distinguished by different markings or by the greater length

of certain portions, are met only, to any appreciable extent, in the frugivorous bats in which the sense of sight

is well developed." This last remark deserves attention, as bearing on the question whether bright colours are

serviceable to male animals from being ornamental. In one genus of sloths, it is now established, as Dr. Gray

states, "that the males are ornamented differently from the femalesthat is to say, that they have a patch of

soft short hair between the shoulders, which is generally of a more or less orange colour, and in one species

The terrestrial Carnivora and Insectivora rarely exhibit sexual differences of any kind, including colour. The

ocelot (Felis pardalis), however, is exceptional, for the colours of the female, compared with those of the

male, are "moins apparentes, le fauve, etant plus terne, le blanc moins pur, les raies ayant moins de largeur et

les taches moins de diametre." (22. Desmarest, 'Mammalogie,' 1820, p. 220. On Felis mitis, Rengger, ibid. s.

194.) The sexes of the allied Felis mitis also differ, but in a less degree; the general hues of the female being

rather paler than in the male, with the spots less black. The marine Carnivora or seals, on the other hand,

sometimes differ considerably in colour, and they present, as we have already seen, other remarkable sexual

differences. Thus the male of the Otaria nigrescens of the southern hemisphere is of a rich brown shade

above; whilst the female, who acquires her adult tints earlier in life than the male, is darkgrey above, the

young of both sexes being of a deep chocolate colour. The male of the northern Phoca groenlandica is tawny

grey, with a curious saddleshaped dark mark on the back; the female is much smaller, and has a very

different appearance, being "dull white or yellowish strawcolour, with a tawny hue on the back"; the young

at first are pure white, and can "hardly be distinguished among the icy hummocks and snow, their colour thus

acting as a protection." (23. Dr. Murie on the Otaria, 'Proceedings Zoological Society,' 1869, p. 108. Mr. R.

Brown on the P. groenlandica, ibid. 1868, p. 417. See also on the colours of seals, Desmarest, ibid. pp. 243,

With Ruminants sexual differences of colour occur more commonly than in any other order. A difference of

this kind is general in the Strepsicerene antelopes; thus the male nilghau (Portax picta) is bluishgrey and

much darker than the female, with the square white patch on the throat, the white marks on the fetlocks, and

the black spots on the ears all much more distinct. We have seen that in this species the crests and tufts of hair

are likewise more developed in the male than in the hornless female. I am informed by Mr. Blyth that the

male, without shedding his hair, periodically becomes darker during the breedingseason. Young males

cannot be distinguished from young females until about twelve months old; and if the male is emasculated

before this period, he never, according to the same authority, changes colour. The importance of this latter

fact, as evidence that the colouring of the Portax is of sexual origin, becomes obvious, when we hear (24.

Judge Caton, in 'Transactions of the Ottawa Academy of Natural Sciences,' 1868, p. 4.) that neither the red

summercoat nor the blue wintercoat of the Virginian deer is at all affected by emasculation. With most or

all of the highlyornamented species of Tragelaphus the males are darker than the hornless females, and their

crests of hair are more fully developed. In the male of that magnificent antelope, the Derbyan eland, the body

is redder, the whole neck much blacker, and the white band which separates these colours broader than in the

female. In the Cape eland, also, the male is slightly darker than the female. (25. Dr. Gray, 'Cat. of Mamm. in

Brit. Mus.' part iii. 1852, pp. 134142; also Dr. Gray, 'Gleanings from the Menagerie of Knowsley,' in which

there is a splendid drawing of the Oreas derbianus: see the text on Tragelaphus. For the Cape eland (Oreas

canna), see Andrew Smith, 'Zoology of S. Africa,' pl. 41 and 42. There are also many of these Antelopes in

In the Indian blackbuck (A. bezoartica), which belongs to another tribe of antelopes, the male is very dark,

almost black; whilst the hornless female is fawncoloured. We meet in this species, as Mr. Blyth informs me,

with an exactly similar series of facts, as in the Portax picta, namely, in the male periodically changing colour

during the breedingseason, in the effects of emasculation on this change, and in the young of both sexes

being indistinguishable from each other. In the Antilope niger the male is black, the female, as well as the

young of both sexes, being brown; in A. singsing the male is much brighter coloured than the hornless

female, and his chest and belly are blacker; in the male A. caama, the marks and lines which occur on various

parts of the body are black, instead of brown as in the female; in the brindled gnu (A. gorgon) "the colours of

the male are nearly the same as those of the female, only deeper and of a brighter hue." (26. On the Ant.

niger, see 'Proc. Zool. Soc.' 1850, p. 133. With respect to an allied species, in which there is an equal sexual

difference in colour, see Sir S. Baker, 'The Albert Nyanza,' 1866, vol. ii. p. 627. For the A. singsing, Gray,

'Cat. B. Mus.' p. 100. Desmarest, 'Mammalogie,' p. 468, on the A. caama. Andrew Smith, 'Zoology of S.

The Banteng bull (Bos sondaicus) of the Malayan Archipelago is almost black, with white legs and buttocks;

the cow is of a bright dun, as are the young males until about the age of three years, when they rapidly change

colour. The emasculated bull reverts to the colour of the female. The female Kemas goat is paler, and both it

and the female Capra aegagrus are said to be more uniformly tinted than their males. Deer rarely present any

sexual differences in colour. Judge Caton, however, informs me that in the males of the wapiti deer (Cervus

canadensis) the neck, belly, and legs are much darker than in the female; but during the winter the darker tints

gradually fade away and disappear. I may here mention that Judge Caton has in his park three races of the

Virginian deer, which differ slightly in colour, but the differences are almost exclusively confined to the blue

winter or breedingcoat; so that this case may be compared with those given in a previous chapter of

closelyallied or representative species of birds, which differ from each other only in their breeding plumage.

(27. 'Ottawa Academy of Sciences,' May 21, 1868, pp. 3, 5.) The females of Cervus paludosus of S. America,

as well as the young of both sexes, do not possess the black stripes on the nose and the blackishbrown line

on the breast, which are characteristic of the adult males. (28. S. Muller, on the Banteng, 'Zoog. Indischen

Archipel.' 18391844, tab. 35; see also Raffles, as quoted by Mr. Blyth, in 'Land and Water,' 1867, p. 476.

On goats, Dr. Gray, 'Catalogue of the British Museum,' p. 146; Desmarest, 'Mammalogie,' p. 482. On the

Cervus paludosus, Rengger, ibid. s. 345.) Lastly, as I am informed by Mr. Blyth, the mature male of the

beautifully coloured and spotted axis deer is considerably darker than the female: and this hue the castrated

The last Order which we need consider is that of the Primates. The male of the Lemur macaco is generally

coalblack, whilst the female is brown. (29. Sclater, 'Proc. Zool. Soc.' 1866, p. i. The same fact has also been

fully ascertained by MM. Pollen and van Dam. See, also, Dr. Gray in 'Annals and Magazine of Natural

History,' May 1871, p. 340.) Of the Quadrumana of the New World, the females and young of Mycetes

caraya are greyishyellow and like each other; in the second year the young male becomes reddishbrown; in

the third, black, excepting the stomach, which, however, becomes quite black in the fourth or fifth year.

There is also a stronglymarked difference in colour between the sexes of Mycetes seniculus and Cebus

capucinus; the young of the former, and I believe of the latter species, resembling the females. With Pithecia

leucocephala the young likewise resemble the females, which are brownishblack above and light rustyred

beneath, the adult males being black. The ruff of hair round the face of Ateles marginatus is tinted yellow in

the male and white in the female. Turning to the Old World, the males of Hylobates hoolock are always

black, with the exception of a white band over the brows; the females vary from whitybrown to a dark tint

mixed with black, but are never wholly black. (30. On Mycetes, Rengger, ibid. s. 14; and Brehm, 'Thierleben,'

B. i. s. 96, 107. On Ateles Desmarest, 'Mammalogie,' p. 75. On Hylobates, Blyth, 'Land and Water,' 1867, p.

135. On the Semnopithecus, S. Muller, 'Zoog. Indischen Archipel.' tab. x.) In the beautiful Cercopithecus

diana, the head of the adult male is of an intense black, whilst that of the female is dark grey; in the former

the fur between the thighs is of an elegant fawn colour, in the latter it is paler. In the beautiful and curious

moustache monkey (Cercopithecus cephus) the only difference between the sexes is that the tail of the male is

chestnut and that of the female grey; but Mr. Bartlett informs me that all the hues become more pronounced

in the male when adult, whilst in the female they remain as they were during youth. According to the

coloured figures given by Solomon Muller, the male of Semnopithecus chrysomelas is nearly black, the

female being pale brown. In the Cercopithecus cynosurus and griseoviridis one part of the body, which is

confined to the male sex, is of the most brilliant blue or green, and contrasts strikingly with the naked skin on

Lastly, in the baboon family, the adult male of Cynocephalus hamadryas differs from the female not only by

his immense mane, but slightly in the colour of the hair and of the naked callosities. In the drill (C.

leucophaeus) the females and young are much palercoloured, with less green, than the adult males. No other

member in the whole class of mammals is coloured in so extraordinary a manner as the adult male mandrill

(C. mormon). The face at this age becomes of a fine blue, with the ridge and tip of the nose of the most

brilliant red. According to some authors, the face is also marked with whitish stripes, and is shaded in parts

with black, but the colours appear to be variable. On the forehead there is a crest of hair, and on the chin a

yellow beard. "Toutes les parties superieures de leurs cuisses et le grand espace nu de leurs fesses sont

egalement colores du rouge le plus vif, avec un melange de bleu qui ne manque reellement pas d'elegance."

(31. Gervais, 'Hist. Nat. des Mammiferes,' 1854, p. 103. Figures are given of the skull of the male. Also

Desmarest, 'Mammalogie,' p. 70. Geoffroy St.Hilaire and F. Cuvier, 'Hist. Nat. des Mammiferes,' 1824, tom.

i.) When the animal is excited all the naked parts become much more vividly tinted. Several authors have

used the strongest expressions in describing these resplendent colours, which they compare with those of the

most brilliant birds. Another remarkable peculiarity is that when the great canine teeth are fully developed,

immense protuberances of bone are formed on each cheek, which are deeply furrowed longitudinally, and the

naked skin over them is brilliantly coloured, as justdescribed. (Fig. 69.) In the adult females and in the

young of both sexes these protuberances are scarcely perceptible; and the naked parts are much less bright

coloured, the face being almost black, tinged with blue. In the adult female, however, the nose at certain

In all the cases hitherto given the male is more strongly or brighter coloured than the female, and differs from

the young of both sexes. But as with some few birds it is the female which is brighter coloured than the male,

so with the Rhesus monkey (Macacus rhesus), the female has a large surface of naked skin round the tail, of a

brilliant carmine red, which, as I was assured by the keepers in the Zoological Gardens, periodically becomes

even yet more vivid, and her face also is pale red. On the other hand, in the adult male and in the young of

both sexes (as I saw in the Gardens), neither the naked skin at the posterior end of the body, nor the face,

shew a trace of red. It appears, however, from some published accounts, that the male does occasionally, or

during certain seasons, exhibit some traces of the red. Although he is thus less ornamented than the female,

yet in the larger size of his body larger canine teeth, more developed whiskers, more prominent superciliary

I have now given all the cases known to me of a difference in colour between the sexes of mammals. Some of

these may be the result of variations confined to one sex and transmitted to the same sex, without any good

being gained, and therefore without the aid of selection. We have instances of this with our domesticated

animals, as in the males of certain cats being rustyred, whilst the females are tortoiseshell coloured.

Analogous cases occur in nature: Mr. Bartlett has seen many black varieties of the jaguar, leopard, vulpine

phalanger, and wombat; and he is certain that all, or nearly all these animals, were males. On the other hand,

with wolves, foxes, and apparently American squirrels, both sexes are occasionally born black. Hence it is

quite possible that with some mammals a difference in colour between the sexes, especially when this is

congenital, may simply be the result, without the aid of selection, of the occurrence of one or more variations,

which from the first were sexually limited in their transmission. Nevertheless it is improbable that the

diversified, vivid, and contrasted colours of certain quadrupeds, for instance, of the above monkeys and

antelopes, can thus be accounted for. We should bear in mind that these colours do not appear in the male at

birth, but only at or near maturity; and that unlike ordinary variations, they are lost if the male be

emasculated. It is on the whole probable that the stronglymarked colours and other ornamental characters of

male quadrupeds are beneficial to them in their rivalry with other males, and have consequently been

acquired through sexual selection. This view is strengthened by the differences in colour between the sexes

occurring almost exclusively, as may be collected from the previous details, in those groups and subgroups

of mammals which present other and stronglymarked secondary sexual characters; these being likewise due

Quadrupeds manifestly take notice of colour. Sir S. Baker repeatedly observed that the African elephant and

rhinoceros attacked white or grey horses with special fury. I have elsewhere shewn (32. The 'Variation of

Animals and Plants under Domestication,' 1868, vol. ii. pp. 102, 103.) that halfwild horses apparently prefer

to pair with those of the same colour, and that herds of fallowdeer of different colours, though living

together, have long kept distinct. It is a more significant fact that a female zebra would not admit the

addresses of a male ass until he was painted so as to resemble a zebra, and then, as John Hunter remarks, "she

received him very readily. In this curious fact, we have instinct excited by mere colour, which had so strong

an effect as to get the better of everything else. But the male did not require this, the female being an animal

somewhat similar to himself, was sufficient to rouse him." (33. 'Essays and Observations,' by J. Hunter,

In an earlier chapter we have seen that the mental powers of the higher animals do not differ in kind, though

greatly in degree, from the corresponding powers of man, especially of the lower and barbarous races; and it

would appear that even their taste for the beautiful is not widely different from that of the Quadrumana. As

the negro of Africa raises the flesh on his face into parallel ridges "or cicatrices, high above the natural

surface, which unsightly deformities are considered great personal attractions" (34. Sir S. Baker, 'The Nile

Tributaries of Abyssinia,' 1867.);as negroes and savages in many parts of the world paint their faces with

red, blue, white, or black bars,so the male mandrill of Africa appears to have acquired his

deeplyfurrowed and gaudilycoloured face from having been thus rendered attractive to the female. No

doubt it is to us a most grotesque notion that the posterior end of the body should be coloured for the sake of

ornament even more brilliantly than the face; but this is not more strange than that the tails of many birds

With mammals we do not at present possess any evidence that the males take pains to display their charms

before the female; and the elaborate manner in which this is performed by male birds and other animals is the

strongest argument in favour of the belief that the females admire, or are excited by, the ornaments and

colours displayed before them. There is, however, a striking parallelism between mammals and birds in all

their secondary sexual characters, namely in their weapons for fighting with rival males, in their ornamental

appendages, and in their colours. In both classes, when the male differs from the female, the young of both

sexes almost always resemble each other, and in a large majority of cases resemble the adult female. In both

classes the male assumes the characters proper to his sex shortly before the age of reproduction; and if

emasculated at an early period, loses them. In both classes the change of colour is sometimes seasonal, and

the tints of the naked parts sometimes become more vivid during the act of courtship. In both classes the male

is almost always more vividly or strongly coloured than the female, and is ornamented with larger crests of

hair or feathers, or other such appendages. In a few exceptional cases the female in both classes is more

highly ornamented than the male. With many mammals, and at least in the case of one bird, the male is more

odoriferous than the female. In both classes the voice of the male is more powerful than that of the female.

Considering this parallelism, there can be little doubt that the same cause, whatever it may be, has acted on

mammals and birds; and the result, as far as ornamental characters are concerned, may be attributed, as it

appears to me, to the longcontinued preference of the individuals of one sex for certain individuals of the

opposite sex, combined with their success in leaving a larger number of offspring to inherit their superior

With many birds, ornaments, which analogy leads us to believe were primarily acquired by the males, have

been transmitted equally, or almost equally, to both sexes; and we may now enquire how far this view applies

to mammals. With a considerable number of species, especially of the smaller kinds, both sexes have been

coloured, independently of sexual selection, for the sake of protection; but not, as far as I can judge, in so

many cases, nor in so striking a manner, as in most of the lower classes. Audubon remarks that he often

mistook the muskrat (35. Fiber zibethicus, Audubon and Bachman, 'The Quadrupeds of North America,'

1846, p. 109.), whilst sitting on the banks of a muddy stream, for a clod of earth, so complete was the

resemblance. The hare on her form is a familiar instance of concealment through colour; yet this principle

partly fails in a closelyallied species, the rabbit, for when running to its burrow, it is made conspicuous to

the sportsman, and no doubt to all beasts of prey, by its upturned white tail. No one doubts that the

quadrupeds inhabiting snowclad regions have been rendered white to protect them from their enemies, or to

favour their stealing on their prey. In regions where snow never lies for long, a white coat would be injurious;

consequently, species of this colour are extremely rare in the hotter parts of the world. It deserves notice that

many quadrupeds inhabiting moderately cold regions, although they do not assume a white winter dress,

become paler during this season; and this apparently is the direct result of the conditions to which they have

long been exposed. Pallas (36. 'Novae species Quadrupedum e Glirium ordine,' 1778, p. 7. What I have called

the roe is the Capreolus sibiricus subecaudatus of Pallas.) states that in Siberia a change of this nature occurs

with the wolf, two species of Mustela, the domestic horse, the Equus hemionus, the domestic cow, two

species of antelopes, the musk deer, the roe, elk, and reindeer. The roe, for instance, has a red summer and a

greyishwhite winter coat; and the latter may perhaps serve as a protection to the animal whilst wandering

through the leafless thickets, sprinkled with snow and hoarfrost. If the abovenamed animals were gradually

to extend their range into regions perpetually covered with snow, their pale wintercoats would probably be

rendered through natural selection, whiter and whiter, until they became as white as snow.

Mr. Reeks has given me a curious instance of an animal profiting by being peculiarly coloured. He raised

from fifty to sixty white and brown piebald rabbits in a large walled orchard; and he had at the same time

some similarly coloured cats in his house. Such cats, as I have often noticed, are very conspicuous during

day; but as they used to lie in watch during the dusk at the mouths of the burrows, the rabbits apparently did

not distinguish them from their particoloured brethren. The result was that, within eighteen months, every

one of these particoloured rabbits was destroyed; and there was evidence that this was effected by the cats.

Colour seems to be advantageous to another animal, the skunk, in a manner of which we have had many

instances in other classes. No animal will voluntarily attack one of these creatures on account of the dreadful

odour which it emits when irritated; but during the dusk it would not easily be recognised and might be

attacked by a beast of prey. Hence it is, as Mr. Belt believes (37. 'The Naturalist in Nicaragua,' p. 249.), that

the skunk is provided with a great white bushy tail, which serves as a conspicuous warning.

Although we must admit that many quadrupeds have received their present tints either as a protection, or as

an aid in procuring prey, yet with a host of species, the colours are far too conspicuous and too singularly

arranged to allow us to suppose that they serve for these purposes. We may take as an illustration certain

antelopes; when we see the square white patch on the throat, the white marks on the fetlocks, and the round

black spots on the ears, all more distinct in the male of the Portax picta, than in the female;when we see

that the colours are more vivid, that the narrow white lines on the flank and the broad white bar on the

shoulder are more distinct in the male Oreas derbyanus than in the female;when we see a similar

difference between the sexes of the curiouslyornamented Tragelaphus scriptus (Fig. 70),we cannot

believe that differences of this kind are of any service to either sex in their daily habits of life. It seems a

much more probable conclusion that the various marks were first acquired by the males and their colours

intensified through sexual selection, and then partially transferred to the females. If this view be admitted,

there can be little doubt that the equally singular colours and marks of many other antelopes, though common

to both sexes, have been gained and transmitted in a like manner. Both sexes, for instance, of the koodoo

(Strepsiceros kudu) (Fig. 64) have narrow white vertical lines on their hind flanks, and an elegant angular

white mark on their foreheads. Both sexes in the genus Damalis are very oddly coloured; in D. pygarga the

back and neck are purplishred, shading on the flanks into black; and these colours are abruptly separated

from the white belly and from a large white space on the buttocks; the head is still more oddly coloured, a

large oblong white mask, narrowlyedged with black, covers the face up to the eyes (Fig. 71); there are three

white stripes on the forehead, and the ears are marked with white. The fawns of this species are of a uniform

pale yellowishbrown. In Damalis albifrons the colouring of the head differs from that in the last species in a

single white stripe replacing the three stripes, and in the ears being almost wholly white. (38. See the fine

plates in A. Smith's 'Zoology of South Africa,' and Dr. Gray's 'Gleanings from the Menagerie of Knowsley.')

After having studied to the best of my ability the sexual differences of animals belonging to all classes, I

cannot avoid the conclusion that the curiouslyarranged colours of many antelopes, though common to both

The same conclusion may perhaps be extended to the tiger, one of the most beautiful animals in the world,

the sexes of which cannot be distinguished by colour, even by the dealers in wild beasts. Mr. Wallace

believes (39. 'Westminster Review,' July 1, 1867, p. 5.) that the striped coat of the tiger "so assimilates with

the vertical stems of the bamboo, as to assist greatly in concealing him from his approaching prey." But this

view does not appear to me satisfactory. We have some slight evidence that his beauty may be due to sexual

selection, for in two species of Felis the analogous marks and colours are rather brighter in the male than in

the female. The zebra is conspicuously striped, and stripes cannot afford any protection in the open plains of

South Africa. Burchell (40. 'Travels in South Africa,' 1824, vol. ii. p. 315.) in describing a herd says, "their

sleek ribs glistened in the sun, and the brightness and regularity of their striped coats presented a picture of

extraordinary beauty, in which probably they are not surpassed by any other quadruped." But as throughout

the whole group of the Equidae the sexes are identical in colour, we have here no evidence of sexual

selection. Nevertheless he who attributes the white and dark vertical stripes on the flanks of various antelopes

to this process, will probably extend the same view to the Royal Tiger and beautiful Zebra.

We have seen in a former chapter that when young animals belonging to any class follow nearly the same

habits of life as their parents, and yet are coloured in a different manner, it may be inferred that they have

retained the colouring of some ancient and extinct progenitor. In the family of pigs, and in the tapirs, the

young are marked with longitudinal stripes, and thus differ from all the existing adult species in these two

groups. With many kinds of deer the young are marked with elegant white spots, of which their parents

exhibit not a trace. A graduated series can be followed from the axis deer, both sexes of which at all ages and

during all seasons are beautifully spotted (the male being rather more strongly coloured than the female), to

species in which neither the old nor the young are spotted. I will specify some of the steps in this series. The

Mantchurian deer (Cervus mantchuricus) is spotted during the whole year, but, as I have seen in the

Zoological Gardens, the spots are much plainer during the summer, when the general colour of the coat is

lighter, than during the winter, when the general colour is darker and the horns are fully developed. In the

hogdeer (Hyelaphus porcinus) the spots are extremely conspicuous during the summer when the coat is

reddishbrown, but quite disappear during the winter when the coat is brown. (41. Dr. Gray, 'Gleanings from

the Menagerie of Knowsley,' p. 64. Mr. Blyth, in speaking ('Land and Water,' 1869, p. 42) of the hogdeer of

Ceylon, says it is more brightly spotted with white than the common hogdeer, at the season when it renews

its horns.) In both these species the young are spotted. In the Virginian deer the young are likewise spotted,

and about five per cent. of the adult animals living in Judge Caton's park, as I am informed by him,

temporarily exhibit at the period when the red summer coat is being replaced by the bluish winter coat, a row

of spots on each flank, which are always the same in number, though very variable in distinctness. From this

condition there is but a very small step to the complete absence of spots in the adults at all seasons; and,

lastly, to their absence at all ages and seasons, as occurs with certain species. From the existence of this

perfect series, and more especially from the fawns of so many species being spotted, we may conclude that

the now living members of the deer family are the descendants of some ancient species which, like the axis

deer, was spotted at all ages and seasons. A still more ancient progenitor probably somewhat resembled the

Hyomoschus aquaticusfor this animal is spotted, and the hornless males have large exserted canine teeth,

of which some few true deer still retain rudiments. Hyomoschus, also, offers one of those interesting cases of

a form linking together two groups, for it is intermediate in certain osteological characters between the

pachyderms and ruminants, which were formerly thought to be quite distinct. (42. Falconer and Cautley,

A curious difficulty here arises. If we admit that coloured spots and stripes were first acquired as ornaments,

how comes it that so many existing deer, the descendants of an aboriginally spotted animal, and all the

species of pigs and tapirs, the descendants of an aboriginally striped animal, have lost in their adult state their

former ornaments? I cannot satisfactorily answer this question. We may feel almost sure that the spots and

stripes disappeared at or near maturity in the progenitors of our existing species, so that they were still

retained by the young; and, owing to the law of inheritance at corresponding ages, were transmitted to the

young of all succeeding generations. It may have been a great advantage to the lion and puma, from the open

nature of their usual haunts, to have lost their stripes, and to have been thus rendered less conspicuous to their

prey; and if the successive variations, by which this end was gained, occurred rather late in life, the young

would have retained their stripes, as is now the case. As to deer, pigs, and tapirs, Fritz Muller has suggested

to me that these animals, by the removal of their spots or stripes through natural selection, would have been

less easily seen by their enemies; and that they would have especially required this protection, as soon as the

carnivora increased in size and number during the tertiary periods. This may be the true explanation, but it is

rather strange that the young should not have been thus protected, and still more so that the adults of some

species should have retained their spots, either partially or completely, during part of the year. We know that,

when the domestic ass varies and becomes reddishbrown, grey, or black, the stripes on the shoulders and

even on the spine frequently disappear, though we cannot explain the cause. Very few horses, except

duncoloured kinds, have stripes on any part of their bodies, yet we have good reason to believe that the

aboriginal horse was striped on the legs and spine, and probably on the shoulders. (43. The 'Variation of

Animals and Plants under Domestication,' 1868, vol. i. pp. 6164.) Hence the disappearance of the spots and

stripes in our adult existing deer, pigs, and tapirs, may be due to a change in the general colour of their coats;

but whether this change was effected through sexual or natural selection, or was due to the direct action of the

conditions of life, or to some other unknown cause, it is impossible to decide. An observation made by Mr.

Sclater well illustrates our ignorance of the laws which regulate the appearance and disappearance of stripes;

the species of Asinus which inhabit the Asiatic continent are destitute of stripes, not having even the cross

shoulderstripe, whilst those which inhabit Africa are conspicuously striped, with the partial exception of A.

taeniopus, which has only the cross shoulderstripe and generally some faint bars on the legs; and this

species inhabits the almost intermediate region of Upper Egypt and Abyssinia. (44. 'Proc. Zool. Soc.' 1862, p.

[Fig. 72. Head of Semnopithecus rubicundus. This and the following figures (from Prof. Gervais) are given to

Before we conclude, it will be well to add a few remarks on the ornaments of monkeys. In most of the species

the sexes resemble each other in colour, but in some, as we have seen, the males differ from the females,

especially in the colour of the naked parts of the skin, in the development of the beard, whiskers, and mane.

Many species are coloured either in so extraordinary or so beautiful a manner, and are furnished with such

curious and elegant crests of hair, that we can hardly avoid looking at these characters as having been gained

for the sake of ornament. The accompanying figures (Figs. 72 to 76) serve to shew the arrangement of the

hair on the face and head in several species. It is scarcely conceivable that these crests of hair, and the

strongly contrasted colours of the fur and skin, can be the result of mere variability without the aid of

selection; and it is inconceivable that they can be of use in any ordinary way to these animals. If so, they have

probably been gained through sexual selection, though transmitted equally, or almost equally, to both sexes.

With many of the Quadrumana, we have additional evidence of the action of sexual selection in the greater

size and strength of the males, and in the greater development of their canine teeth, in comparison with the

A few instances will suffice of the strange manner in which both sexes of some species are coloured, and of

the beauty of others. The face of the Cercopithecus petaurista (Fig. 77) is black, the whiskers and beard being

white, with a defined, round, white spot on the nose, covered with short white hair, which gives to the animal

an almost ludicrous aspect. The Semnopithecus frontatus likewise has a blackish face with a long black

beard, and a large naked spot on the forehead of a bluishwhite colour. The face of Macacus lasiotus is dirty

fleshcoloured, with a defined red spot on each cheek. The appearance of Cercocebus aethiops is grotesque,

with its black face, white whiskers and collar, chestnut head, and a large naked white spot over each eyelid.

In very many species, the beard, whiskers, and crests of hair round the face are of a different colour from the

rest of the head, and when different, are always of a lighter tint (45. I observed this fact in the Zoological

Gardens; and many cases may be seen in the coloured plates in Geoffroy St.Hilaire and F. Cuvier, 'Histoire

Nat. des Mammiferes,' tom. i. 1824.), being often pure white, sometimes bright yellow, or reddish. The whole

face of the South American Brachyurus calvus is of a "glowing scarlet hue"; but this colour does not appear

until the animal is nearly mature. (46. Bates, 'The Naturalist on the Amazons,' 1863, vol. ii. p. 310.) The

naked skin of the face differs wonderfully in colour in the various species. It is often brown or fleshcolour,

with parts perfectly white, and often as black as that of the most sooty negro. In the Brachyurus the scarlet

tint is brighter than that of the most blushing Caucasian damsel. It is sometimes more distinctly orange than

in any Mongolian, and in several species it is blue, passing into violet or grey. In all the species known to Mr.

Bartlett, in which the adults of both sexes have stronglycoloured faces, the colours are dull or absent during

early youth. This likewise holds good with the mandrill and Rhesus, in which the face and the posterior parts

of the body are brilliantly coloured in one sex alone. In these latter cases we have reason to believe that the

colours were acquired through sexual selection; and we are naturally led to extend the same view to the

foregoing species, though both sexes when adult have their faces coloured in the same manner.

Although many kinds of monkeys are far from beautiful according to our taste, other species are universally

admired for their elegant appearance and bright colours. The Semnopithecus nemaeus, though peculiarly

coloured, is described as extremely pretty; the orangetinted face is surrounded by long whiskers of glossy

whiteness, with a line of chestnutred over the eyebrows; the fur on the back is of a delicate grey, with a

square patch on the loins, the tail and the forearms being of a pure white; a gorget of chestnut surmounts the

chest; the thighs are black, with the legs chestnut red. I will mention only two other monkeys for their

beauty; and I have selected these as presenting slight sexual differences in colour, which renders it in some

degree probable that both sexes owe their elegant appearance to sexual selection. In the moustachemonkey

(Cercopithecus cephus) the general colour of the fur is mottledgreenish with the throat white; in the male

the end of the tail is chestnut, but the face is the most ornamented part, the skin being chiefly bluishgrey,

shading into a blackish tint beneath the eyes, with the upper lip of a delicate blue, clothed on the lower edge

with a thin black moustache; the whiskers are orangecoloured, with the upper part black, forming a band

which extends backwards to the ears, the latter being clothed with whitish hairs. In the Zoological Society's

Gardens I have often overheard visitors admiring the beauty of another monkey, deservedly called

Cercopithecus diana (Fig. 78); the general colour of the fur is grey; the chest and inner surface of the forelegs

are white; a large triangular defined space on the hinder part of the back is rich chestnut; in the male the inner

sides of the thighs and the abdomen are delicate fawncoloured, and the top of the head is black; the face and

ears are intensely black, contrasting finely with a white transverse crest over the eyebrows and a long white

peaked beard, of which the basal portion is black. (47. I have seen most of the above monkeys in the

Zoological Society's Gardens. The description of the Semnopithecus nemaeus is taken from Mr. W.C.

In these and many other monkeys, the beauty and singular arrangement of their colours, and still more the

diversified and elegant arrangement of the crests and tufts of hair on their heads, force the conviction on my

mind that these characters have been acquired through sexual selection exclusively as ornaments.

The law of battle for the possession of the female appears to prevail throughout the whole great class of

mammals. Most naturalists will admit that the greater size, strength, courage, and pugnacity of the male, his

special weapons of offence, as well as his special means of defence, have been acquired or modified through

that form of selection which I have called sexual. This does not depend on any superiority in the general

struggle for life, but on certain individuals of one sex, generally the male, being successful in conquering

other males, and leaving a larger number of offspring to inherit their superiority than do the less successful

There is another and more peaceful kind of contest, in which the males endeavour to excite or allure the

females by various charms. This is probably carried on in some cases by the powerful odours emitted by the

males during the breedingseason; the odoriferous glands having been acquired through sexual selection.

Whether the same view can be extended to the voice is doubtful, for the vocal organs of the males must have

been strengthened by use during maturity, under the powerful excitements of love, jealousy or rage, and will

consequently have been transmitted to the same sex. Various crests, tufts, and mantles of hair, which are

either confined to the male, or are more developed in this sex than in the female, seem in most cases to be

merely ornamental, though they sometimes serve as a defence against rival males. There is even reason to

suspect that the branching horns of stags, and the elegant horns of certain antelopes, though properly serving

When the male differs in colour from the female, he generally exhibits darker and more stronglycontrasted

tints. We do not in this class meet with the splendid red, blue, yellow, and green tints, so common with male

birds and many other animals. The naked parts, however, of certain Quadrumana must be excepted; for such

parts, often oddly situated, are brilliantly coloured in some species. The colours of the male in other cases

may be due to simple variation, without the aid of selection. But when the colours are diversified and strongly

pronounced, when they are not developed until near maturity, and when they are lost after emasculation, we

can hardly avoid the conclusion that they have been acquired through sexual selection for the sake of

ornament, and have been transmitted exclusively, or almost exclusively, to the same sex. When both sexes

are coloured in the same manner, and the colours are conspicuous or curiously arranged, without being of the

least apparent use as a protection, and especially when they are associated with various other ornamental

appendages, we are led by analogy to the same conclusion, namely, that they have been acquired through

sexual selection, although transmitted to both sexes. That conspicuous and diversified colours, whether

confined to the males or common to both sexes, are as a general rule associated in the same groups and

subgroups with other secondary sexual characters serving for war or for ornament, will be found to hold

The law of the equal transmission of characters to both sexes, as far as colour and other ornaments are

concerned, has prevailed far more extensively with mammals than with birds; but weapons, such as horns and

tusks, have often been transmitted either exclusively or much more perfectly to the males than to the females.

This is surprising, for, as the males generally use their weapons for defence against enemies of all kinds, their

weapons would have been of service to the females. As far as we can see, their absence in this sex can be

accounted for only by the form of inheritance which has prevailed. Finally, with quadrupeds the contest

between the individuals of the same sex, whether peaceful or bloody, has, with the rarest exceptions, been

confined to the males; so that the latter have been modified through sexual selection, far more commonly

than the females, either for fighting with each other or for alluring the opposite sex.

Differences between man and womanCauses of such differences and of certain characters common to both

sexesLaw of battleDifferences in mental powers, and voiceOn the influence of beauty in determining

the marriages of mankindAttention paid by savages to ornamentsTheir ideas of beauty in womanThe

With mankind the differences between the sexes are greater than in most of the Quadrumana, but not so great

as in some, for instance, the mandrill. Man on an average is considerably taller, heavier, and stronger than

woman, with squarer shoulders and more plainlypronounced muscles. Owing to the relation which exists

between muscular development and the projection of the brows (1. Schaaffhausen, translation in

'Anthropological Review,' Oct. 1868, pp. 419, 420, 427.), the superciliary ridge is generally more marked in

man than in woman. His body, and especially his face, is more hairy, and his voice has a different and more

powerful tone. In certain races the women are said to differ slightly in tint from the men. For instance,

Schweinfurth, in speaking of a negress belonging to the Monbuttoos, who inhabit the interior of Africa a few

degrees north of the equator, says, "Like all her race, she had a skin several shades lighter than her husband's,

being something of the colour of halfroasted coffee." (2. 'The Heart of Africa,' English transl. 1873, vol i. p.

544.) As the women labour in the fields and are quite unclothed, it is not likely that they differ in colour from

the men owing to less exposure to the weather. European women are perhaps the brighter coloured of the two

Man is more courageous, pugnacious and energetic than woman, and has a more inventive genius. His brain

is absolutely larger, but whether or not proportionately to his larger body, has not, I believe, been fully

ascertained. In woman the face is rounder; the jaws and the base of the skull smaller; the outlines of the body

rounder, in parts more prominent; and her pelvis is broader than in man (3. Ecker, translation, in

'Anthropological Review,' Oct. 1868, pp. 351356. The comparison of the form of the skull in men and

women has been followed out with much care by Welcker.); but this latter character may perhaps be

considered rather as a primary than a secondary sexual character. She comes to maturity at an earlier age than

As with animals of all classes, so with man, the distinctive characters of the male sex are not fully developed

until he is nearly mature; and if emasculated they never appear. The beard, for instance, is a secondary sexual

character, and male children are beardless, though at an early age they have abundant hair on the head. It is

probably due to the rather late appearance in life of the successive variations whereby man has acquired his

masculine characters, that they are transmitted to the male sex alone. Male and female children resemble each

other closely, like the young of so many other animals in which the adult sexes differ widely; they likewise

resemble the mature female much more closely than the mature male. The female, however, ultimately

assumes certain distinctive characters, and in the formation of her skull, is said to be intermediate between the

child and the man. (4. Ecker and Welcker, ibid. pp. 352, 355; Vogt, 'Lectures on Man,' Eng. translat. p. 81.)

Again, as the young of closely allied though distinct species do not differ nearly so much from each other as

do the adults, so it is with the children of the different races of man. Some have even maintained that

racedifferences cannot be detected in the infantile skull. (5. Schaaffhausen, 'Anthropolog. Review,' ibid. p.

429.) In regard to colour, the newborn negro child is reddish nutbrown, which soon becomes slatygrey;

the black colour being fully developed within a year in the Soudan, but not until three years in Egypt. The

eyes of the negro are at first blue, and the hair chestnutbrown rather than black, being curled only at the

ends. The children of the Australians immediately after birth are yellowishbrown, and become dark at a later

age. Those of the Guaranys of Paraguay are whitishyellow, but they acquire in the course of a few weeks

the yellowishbrown tint of their parents. Similar observations have been made in other parts of America. (6.

PrunerBey, on negro infants as quoted by Vogt, 'Lectures on Man,' Eng. translat. 1864, p. 189: for further

facts on negro infants, as quoted from Winterbottom and Camper, see Lawrence, 'Lectures on Physiology,'

etc. 1822, p. 451. For the infants of the Guaranys, see Rengger, 'Saugethiere,' etc. s. 3. See also Godron, 'De

l'Espece,' tom. ii. 1859, p. 253. For the Australians, Waitz, 'Introduction to Anthropology,' Eng. translat.

I have specified the foregoing differences between the male and female sex in mankind, because they are

curiously like those of the Quadrumana. With these animals the female is mature at an earlier age than the

male; at least this is certainly the case in Cebus azarae. (7. Rengger, 'Saugethiere,' etc., 1830, s. 49.) The

males of most species are larger and stronger than the females, of which fact the gorilla affords a well

known instance. Even in so trifling a character as the greater prominence of the superciliary ridge, the males

of certain monkeys differ from the females (8. As in Macacus cynomolgus (Desmarest, 'Mammalogie,' p. 65),

and in Hylobates agilis (Geoffroy St.Hilaire and F. Cuvier, 'Histoire Nat. des Mammiferes,' 1824, tom. i. p.

2).), and agree in this respect with mankind. In the gorilla and certain other monkeys, the cranium of the adult

male presents a stronglymarked sagittal crest, which is absent in the female; and Ecker found a trace of a

similar difference between the two sexes in the Australians. (9. 'Anthropological Review,' Oct. 1868, p. 353.)

With monkeys when there is any difference in the voice, that of the male is the more powerful. We have seen

that certain male monkeys have a well developed beard, which is quite deficient, or much less developed in

the female. No instance is known of the beard, whiskers, or moustache being larger in the female than in the

male monkey. Even in the colour of the beard there is a curious parallelism between man and the

Quadrumana, for with man when the beard differs in colour from the hair of the head, as is commonly the

case, it is, I believe, almost always of a lighter tint, being often reddish. I have repeatedly observed this fact in

England; but two gentlemen have lately written to me, saying that they form an exception to the rule. One of

these gentlemen accounts for the fact by the wide difference in colour of the hair on the paternal and maternal

sides of his family. Both had been long aware of this peculiarity (one of them having often been accused of

dyeing his beard), and had been thus led to observe other men, and were convinced that the exceptions were

very rare. Dr. Hooker attended to this little point for me in Russia, and found no exception to the rule. In

Calcutta, Mr. J. Scott, of the Botanic Gardens, was so kind as to observe the many races of men to be seen

there, as well as in some other parts of India, namely, two races of Sikhim, the Bhoteas, Hindoos, Burmese,

and Chinese, most of which races have very little hair on the face; and he always found that when there was

any difference in colour between the hair of the head and the beard, the latter was invariably lighter. Now

with monkeys, as has already been stated, the beard frequently differs strikingly in colour from the hair of the

head, and in such cases it is always of a lighter hue, being often pure white, sometimes yellow or reddish. (10.

Mr. Blyth informs me that he has only seen one instance of the beard, whiskers, etc., in a monkey becoming

white with old age, as is so commonly the case with us. This, however, occurred in an aged Macacus

cynomolgus, kept in confinement whose moustaches were "remarkably long and humanlike." Altogether

this old monkey presented a ludicrous resemblance to one of the reigning monarchs of Europe, after whom he

was universally nicknamed. In certain races of man the hair on the head hardly ever becomes grey; thus Mr.

D. Forbes has never, as he informs me, seen an instance with the Aymaras and Quichuas of South America.)

In regard to the general hairiness of the body, the women in all races are less hairy than the men; and in some

few Quadrumana the under side of the body of the female is less hairy than that of the male. (11. This is the

case with the females of several species of Hylobates; see Geoffroy St. Hilaire and F. Cuvier, 'Hist. Nat. des

Mamm.' tom. i. See also, on H. lar, 'Penny Cyclopedia,' vol. ii. pp. 149, 150.) Lastly, male monkeys, like

men, are bolder and fiercer than the females. They lead the troop, and when there is danger, come to the front.

We thus see how close is the parallelism between the sexual differences of man and the Quadrumana. With

some few species, however, as with certain baboons, the orang and the gorilla, there is a considerably greater

difference between the sexes, as in the size of the canine teeth, in the development and colour of the hair, and

All the secondary sexual characters of man are highly variable, even within the limits of the same race; and

they differ much in the several races. These two rules hold good generally throughout the animal kingdom. In

the excellent observations made on board the Novara (12. The results were deduced by Dr. Weisbach from

the measurements made by Drs. K. Scherzer and Schwarz, see 'Reise der Novara: Anthropolog. Theil,' 1867,

ss. 216, 231, 234, 236, 239, 269.), the male Australians were found to exceed the females by only 65 millim.

in height, whilst with the Javans the average excess was 218 millim.; so that in this latter race the difference

in height between the sexes is more than thrice as great as with the Australians. Numerous measurements

were carefully made of the stature, the circumference of the neck and chest, the length of the backbone and

of the arms, in various races; and nearly all these measurements shew that the males differ much more from

one another than do the females. This fact indicates that, as far as these characters are concerned, it is the

male which has been chiefly modified, since the several races diverged from their common stock.

The development of the beard and the hairiness of the body differ remarkably in the men of distinct races,

and even in different tribes or families of the same race. We Europeans see this amongst ourselves. In the

Island of St. Kilda, according to Martin (13. 'Voyage to St. Kilda' (3rd ed. 1753), p. 37.), the men do not

acquire beards until the age of thirty or upwards, and even then the beards are very thin. On the

EuropaeoAsiatic continent, beards prevail until we pass beyond India; though with the natives of Ceylon

they are often absent, as was noticed in ancient times by Diodorus. (14. Sir J.E. Tennent, 'Ceylon,' vol. ii.

1859, p. 107.) Eastward of India beards disappear, as with the Siamese, Malays, Kalmucks, Chinese, and

Japanese; nevertheless, the Ainos (15. Quatrefages, 'Revue des Cours Scientifiques,' Aug. 29, 1868, p. 630;

Vogt, 'Lectures on Man,' Eng. trans. p. 127.), who inhabit the northernmost islands of the Japan Archipelago,

are the hairiest men in the world. With negroes the beard is scanty or wanting, and they rarely have whiskers;

in both sexes the body is frequently almost destitute of fine down. (16. On the beards of negroes, Vogt,

'Lectures,' etc. p. 127; Waitz, 'Introduct. to Anthropology,' Engl. translat. 1863, vol. i. p. 96. It is remarkable

that in the United States ('Investigations in Military and Anthropological Statistics of American Soldiers,'

1869, p. 569) the pure negroes and their crossed offspring seem to have bodies almost as hairy as Europeans.)

On the other hand, the Papuans of the Malay Archipelago, who are nearly as black as negroes, possess

welldeveloped beards. (17. Wallace, 'The Malay Arch.' vol. ii. 1869, p. 178.) In the Pacific Ocean the

inhabitants of the Fiji Archipelago have large bushy beards, whilst those of the not distant archipelagoes of

Tonga and Samoa are beardless; but these men belong to distinct races. In the Ellice group all the inhabitants

belong to the same race; yet on one island alone, namely Nunemaya, "the men have splendid beards"; whilst

on the other islands "they have, as a rule, a dozen straggling hairs for a beard." (18. Dr. J. Barnard Davis on

Throughout the great American continent the men may be said to be beardless; but in almost all the tribes a

few short hairs are apt to appear on the face, especially in old age. With the tribes of North America, Catlin

estimates that eighteen out of twenty men are completely destitute by nature of a beard; but occasionally there

may be seen a man, who has neglected to pluck out the hairs at puberty, with a soft beard an inch or two in

length. The Guaranys of Paraguay differ from all the surrounding tribes in having a small beard, and even

some hair on the body, but no whiskers. (19. Catlin, 'North American Indians,' 3rd. ed. 1842, vol. ii. p. 227.

On the Guaranys, see Azara, 'Voyages dans l'Amerique Merid.' tom. ii. 1809, p. 85; also Rengger,

'Saugethiere von Paraguay,' s. 3.) I am informed by Mr. D. Forbes, who particularly attended to this point,

that the Aymaras and Quichuas of the Cordillera are remarkably hairless, yet in old age a few straggling hairs

occasionally appear on the chin. The men of these two tribes have very little hair on the various parts of the

body where hair grows abundantly in Europeans, and the women have none on the corresponding parts. The

hair on the head, however, attains an extraordinary length in both sexes, often reaching almost to the ground;

and this is likewise the case with some of the N. American tribes. In the amount of hair, and in the general

shape of the body, the sexes of the American aborigines do not differ so much from each other, as in most

other races. (20. Prof. and Mrs. Agassiz ('Journey in Brazil,' p. 530) remark that the sexes of the American

Indians differ less than those of the negroes and of the higher races. See also Rengger, ibid. p. 3, on the

Guaranys.) This fact is analogous with what occurs with some closely allied monkeys; thus the sexes of the

chimpanzee are not as different as those of the orang or gorilla. (21. Rutimeyer, 'Die Grenzen der Thierwelt;

In the previous chapters we have seen that with mammals, birds, fishes, insects, etc., many characters, which

there is every reason to believe were primarily gained through sexual selection by one sex, have been

transferred to the other. As this same form of transmission has apparently prevailed much with mankind, it

will save useless repetition if we discuss the origin of characters peculiar to the male sex together with certain

With savages, for instance, the Australians, the women are the constant cause of war both between members

of the same tribe and between distinct tribes. So no doubt it was in ancient times; "nam fuit ante Helenam

mulier teterrima belli causa." With some of the North American Indians, the contest is reduced to a system.

That excellent observer, Hearne (22. 'A Journey from Prince of Wales Fort,' 8vo. ed. Dublin, 1796, p. 104. Sir

J. Lubbock ('Origin of Civilisation,' 1870, p. 69) gives other and similar cases in North America. For the

Guanas of South America see Azara, 'Voyages,' etc. tom. ii. p. 94.), says:"It has ever been the custom

among these people for the men to wrestle for any woman to whom they are attached; and, of course, the

strongest party always carries off the prize. A weak man, unless he be a good hunter, and wellbeloved, is

seldom permitted to keep a wife that a stronger man thinks worth his notice. This custom prevails throughout

all the tribes, and causes a great spirit of emulation among their youth, who are upon all occasions, from their

childhood, trying their strength and skill in wrestling." With the Guanas of South America, Azara states that

the men rarely marry till twenty years old or more, as before that age they cannot conquer their rivals.

Other similar facts could be given; but even if we had no evidence on this head, we might feel almost sure,

from the analogy of the higher Quadrumana (23. On the fighting of the male gorillas, see Dr. Savage, in

'Boston Journal of Natural History,' vol. v. 1847, p. 423. On Presbytis entellus, see the 'Indian Field,' 1859, p.

146.), that the law of battle had prevailed with man during the early stages of his development. The

occasional appearance at the present day of canine teeth which project above the others, with traces of a

diastema or open space for the reception of the opposite canines, is in all probability a case of reversion to a

former state, when the progenitors of man were provided with these weapons, like so many existing male

Quadrumana. It was remarked in a former chapter that as man gradually became erect, and continually used

his hands and arms for fighting with sticks and stones, as well as for the other purposes of life, he would have

used his jaws and teeth less and less. The jaws, together with their muscles, would then have been reduced

through disuse, as would the teeth through the not well understood principles of correlation and economy of

growth; for we everywhere see that parts, which are no longer of service, are reduced in size. By such steps

the original inequality between the jaws and teeth in the two sexes of mankind would ultimately have been

obliterated. The case is almost parallel with that of many male Ruminants, in which the canine teeth have

been reduced to mere rudiments, or have disappeared, apparently in consequence of the development of

horns. As the prodigious difference between the skulls of the two sexes in the orang and gorilla stands in

close relation with the development of the immense canine teeth in the males, we may infer that the reduction

of the jaws and teeth in the early male progenitors of man must have led to a most striking and favourable

There can be little doubt that the greater size and strength of man, in comparison with woman, together with

his broader shoulders, more developed muscles, rugged outline of body, his greater courage and pugnacity,

are all due in chief part to inheritance from his halfhuman male ancestors. These characters would, however,

have been preserved or even augmented during the long ages of man's savagery, by the success of the

strongest and boldest men, both in the general struggle for life and in their contests for wives; a success

which would have ensured their leaving a more numerous progeny than their less favoured brethren. It is not

probable that the greater strength of man was primarily acquired through the inherited effects of his having

worked harder than woman for his own subsistence and that of his family; for the women in all barbarous

nations are compelled to work at least as hard as the men. With civilised people the arbitrament of battle for

the possession of the women has long ceased; on the other hand, the men, as a general rule, have to work

harder than the women for their joint subsistence, and thus their greater strength will have been kept up.

With respect to differences of this nature between man and woman, it is probable that sexual selection has

played a highly important part. I am aware that some writers doubt whether there is any such inherent

difference; but this is at least probable from the analogy of the lower animals which present other secondary

sexual characters. No one disputes that the bull differs in disposition from the cow, the wildboar from the

sow, the stallion from the mare, and, as is well known to the keepers of menageries, the males of the larger

apes from the females. Woman seems to differ from man in mental disposition, chiefly in her greater

tenderness and less selfishness; and this holds good even with savages, as shewn by a wellknown passage in

Mungo Park's Travels, and by statements made by many other travellers. Woman, owing to her maternal

instincts, displays these qualities towards her infants in an eminent degree; therefore it is likely that she

would often extend them towards her fellowcreatures. Man is the rival of other men; he delights in

competition, and this leads to ambition which passes too easily into selfishness. These latter qualities seem to

be his natural and unfortunate birthright. It is generally admitted that with woman the powers of intuition, of

rapid perception, and perhaps of imitation, are more strongly marked than in man; but some, at least, of these

faculties are characteristic of the lower races, and therefore of a past and lower state of civilisation.

The chief distinction in the intellectual powers of the two sexes is shewn by man's attaining to a higher

eminence, in whatever he takes up, than can womanwhether requiring deep thought, reason, or

imagination, or merely the use of the senses and hands. If two lists were made of the most eminent men and

women in poetry, painting, sculpture, music (inclusive both of composition and performance), history,

science, and philosophy, with halfadozen names under each subject, the two lists would not bear

comparison. We may also infer, from the law of the deviation from averages, so well illustrated by Mr.

Galton, in his work on 'Hereditary Genius,' that if men are capable of a decided preeminence over women in

Amongst the halfhuman progenitors of man, and amongst savages, there have been struggles between the

males during many generations for the possession of the females. But mere bodily strength and size would do

little for victory, unless associated with courage, perseverance, and determined energy. With social animals,

the young males have to pass through many a contest before they win a female, and the older males have to

retain their females by renewed battles. They have, also, in the case of mankind, to defend their females, as

well as their young, from enemies of all kinds, and to hunt for their joint subsistence. But to avoid enemies or

to attack them with success, to capture wild animals, and to fashion weapons, requires the aid of the higher

mental faculties, namely, observation, reason, invention, or imagination. These various faculties will thus

have been continually put to the test and selected during manhood; they will, moreover, have been

strengthened by use during this same period of life. Consequently in accordance with the principle often

alluded to, we might expect that they would at least tend to be transmitted chiefly to the male offspring at the

Now, when two men are put into competition, or a man with a woman, both possessed of every mental

quality in equal perfection, save that one has higher energy, perseverance, and courage, the latter will

generally become more eminent in every pursuit, and will gain the ascendancy. (24. J. Stuart Mill remarks

('The Subjection of Women,' 1869, p. 122), "The things in which man most excels woman are those which

require most plodding, and long hammering at single thoughts." What is this but energy and perseverance?)

He may be said to possess geniusfor genius has been declared by a great authority to be patience; and

patience, in this sense, means unflinching, undaunted perseverance. But this view of genius is perhaps

deficient; for without the higher powers of the imagination and reason, no eminent success can be gained in

many subjects. These latter faculties, as well as the former, will have been developed in man, partly through

sexual selection,that is, through the contest of rival males, and partly through natural selection, that is,

from success in the general struggle for life; and as in both cases the struggle will have been during maturity,

the characters gained will have been transmitted more fully to the male than to the female offspring. It

accords in a striking manner with this view of the modification and reinforcement of many of our mental

faculties by sexual selection, that, firstly, they notoriously undergo a considerable change at puberty (25.

Maudsley, 'Mind and Body,' p. 31.), and, secondly, that eunuchs remain throughout life inferior in these same

qualities. Thus, man has ultimately become superior to woman. It is, indeed, fortunate that the law of the

equal transmission of characters to both sexes prevails with mammals; otherwise, it is probable that man

would have become as superior in mental endowment to woman, as the peacock is in ornamental plumage to

It must be borne in mind that the tendency in characters acquired by either sex late in life, to be transmitted to

the same sex at the same age, and of early acquired characters to be transmitted to both sexes, are rules

which, though general, do not always hold. If they always held good, we might conclude (but I here exceed

my proper bounds) that the inherited effects of the early education of boys and girls would be transmitted

equally to both sexes; so that the present inequality in mental power between the sexes would not be effaced

by a similar course of early training; nor can it have been caused by their dissimilar early training. In order

that woman should reach the same standard as man, she ought, when nearly adult, to be trained to energy and

perseverance, and to have her reason and imagination exercised to the highest point; and then she would

probably transmit these qualities chiefly to her adult daughters. All women, however, could not be thus

raised, unless during many generations those who excelled in the above robust virtues were married, and

produced offspring in larger numbers than other women. As before remarked of bodily strength, although

men do not now fight for their wives, and this form of selection has passed away, yet during manhood, they

generally undergo a severe struggle in order to maintain themselves and their families; and this will tend to

keep up or even increase their mental powers, and, as a consequence, the present inequality between the

sexes. (26. An observation by Vogt bears on this subject: he says, "It is a remarkable circumstance, that the

difference between the sexes, as regards the cranial cavity, increases with the development of the race, so that

the male European excels much more the female, than the negro the negress. Welcker confirms this statement

of Huschke from his measurements of negro and German skulls." But Vogt admits ('Lectures on Man,' Eng.

In some species of Quadrumana there is a great difference between the adult sexes, in the power of their

voices and in the development of the vocal organs; and man appears to have inherited this difference from his

early progenitors. His vocal cords are about onethird longer than in woman, or than in boys; and

emasculation produces the same effect on him as on the lower animals, for it "arrests that prominent growth

of the thyroid, etc., which accompanies the elongation of the cords." (27. Owen, 'Anatomy of Vertebrates,'

vol. iii. p. 603.) With respect to the cause of this difference between the sexes, I have nothing to add to the

remarks in the last chapter on the probable effects of the longcontinued use of the vocal organs by the male

under the excitement of love, rage and jealousy. According to Sir Duncan Gibb (28. 'Journal of the

Anthropological Society,' April 1869, p. lvii. and lxvi.), the voice and the form of the larynx differ in the

different races of mankind; but with the Tartars, Chinese, etc., the voice of the male is said not to differ so

The capacity and love for singing or music, though not a sexual character in man, must not here be passed

over. Although the sounds emitted by animals of all kinds serve many purposes, a strong case can be made

out, that the vocal organs were primarily used and perfected in relation to the propagation of the species.

Insects and some few spiders are the lowest animals which voluntarily produce any sound; and this is

generally effected by the aid of beautifully constructed stridulating organs, which are often confined to the

males. The sounds thus produced consist, I believe in all cases, of the same note, repeated rhythmically (29.

Dr. Scudder, 'Notes on Stridulation,' in 'Proc. Boston Soc. of Nat. Hist.' vol. xi. April 1868.); and this is

sometimes pleasing even to the ears of man. The chief and, in some cases, exclusive purpose appears to be

The sounds produced by fishes are said in some cases to be made only by the males during the

breedingseason. All the airbreathing Vertebrata necessarily possess an apparatus for inhaling and expelling

air, with a pipe capable of being closed at one end. Hence when the primeval members of this class were

strongly excited and their muscles violently contracted, purposeless sounds would almost certainly have been

produced; and these, if they proved in any way serviceable, might readily have been modified or intensified

by the preservation of properly adapted variations. The lowest Vertebrates which breathe air are Amphibians;

and of these, frogs and toads possess vocal organs, which are incessantly used during the breeding season,

and which are often more highly developed in the male than in the female. The male alone of the tortoise

utters a noise, and this only during the season of love. Male alligators roar or bellow during the same season.

Every one knows how much birds use their vocal organs as a means of courtship; and some species likewise

In the class of Mammals, with which we are here more particularly concerned, the males of almost all the

species use their voices during the breedingseason much more than at any other time; and some are

absolutely mute excepting at this season. With other species both sexes, or only the females, use their voices

as a lovecall. Considering these facts, and that the vocal organs of some quadrupeds are much more largely

developed in the male than in the female, either permanently or temporarily during the breedingseason; and

considering that in most of the lower classes the sounds produced by the males, serve not only to call but to

excite or allure the female, it is a surprising fact that we have not as yet any good evidence that these organs

are used by male mammals to charm the females. The American Mycetes caraya perhaps forms an exception,

as does the Hylobates agilis, an ape allied to man. This gibbon has an extremely loud but musical voice. Mr.

Waterhouse states (30. Given in W.C.L. Martin's 'General Introduction to Natural History of Mamm.

Animals,' 1841, p. 432; Owen, 'Anatomy of Vertebrates,' vol. iii, p. 600.), "It appeared to me that in

ascending and descending the scale, the intervals were always exactly halftones; and I am sure that the

highest note was the exact octave to the lowest. The quality of the notes is very musical; and I do not doubt

that a good violinist would be able to give a correct idea of the gibbon's composition, excepting as regards its

loudness." Mr. Waterhouse then gives the notes. Professor Owen, who is a musician, confirms the foregoing

statement, and remarks, though erroneously, that this gibbon "alone of brute mammals may be said to sing."

It appears to be much excited after its performance. Unfortunately, its habits have never been closely

observed in a state of nature; but from the analogy of other animals, it is probable that it uses its musical

This gibbon is not the only species in the genus which sings, for my son, Francis Darwin, attentively listened

in the Zoological Gardens to H. leuciscus whilst singing a cadence of three notes, in true musical intervals

and with a clear musical tone. It is a more surprising fact that certain rodents utter musical sounds. Singing

mice have often been mentioned and exhibited, but imposture has commonly been suspected. We have,

however, at last a clear account by a wellknown observer, the Rev. S. Lockwood (31. The 'American

Naturalist,' 1871, p. 761.), of the musical powers of an American species, the Hesperomys cognatus,

belonging to a genus distinct from that of the English mouse. This little animal was kept in confinement, and

the performance was repeatedly heard. In one of the two chief songs, "the last bar would frequently be

prolonged to two or three; and she would sometimes change from C sharp and D, to C natural and D, then

warble on these two notes awhile, and wind up with a quick chirp on C sharp and D. The distinctness

between the semitones was very marked, and easily appreciable to a good ear." Mr. Lockwood gives both

songs in musical notation; and adds that though this little mouse "had no ear for time, yet she would keep to

the key of B (two flats) and strictly in a major key."..."Her soft clear voice falls an octave with all the

precision possible; then at the wind up, it rises again into a very quick trill on C sharp and D."

A critic has asked how the ears of man, and he ought to have added of other animals, could have been

adapted by selection so as to distinguish musical notes. But this question shews some confusion on the

subject; a noise is the sensation resulting from the coexistence of several aerial "simple vibrations" of

various periods, each of which intermits so frequently that its separate existence cannot be perceived. It is

only in the want of continuity of such vibrations, and in their want of harmony inter se, that a noise differs

from a musical note. Thus an ear to be capable of discriminating noisesand the high importance of this

power to all animals is admitted by every onemust be sensitive to musical notes. We have evidence of this

capacity even low down in the animal scale: thus Crustaceans are provided with auditory hairs of different

lengths, which have been seen to vibrate when the proper musical notes are struck. (32. Helmholtz, 'Theorie

Phys. de la Musique,' 1868, p. 187.) As stated in a previous chapter, similar observations have been made on

the hairs of the antennae of gnats. It has been positively asserted by good observers that spiders are attracted

by music. It is also well known that some dogs howl when hearing particular tones. (33. Several accounts

have been published to this effect. Mr. Peach writes to me that an old dog of his howls when B flat is sounded

on the flute, and to no other note. I may add another instance of a dog always whining, when one note on a

concertina, which was out of tune, was played.) Seals apparently appreciate music, and their fondness for it

"was well known to the ancients, and is often taken advantage of by the hunters at the present day." (34. Mr.

Therefore, as far as the mere perception of musical notes is concerned, there seems no special difficulty in the

case of man or of any other animal. Helmholtz has explained on physiological principles why concords are

agreeable, and discords disagreeable to the human ear; but we are little concerned with these, as music in

harmony is a late invention. We are more concerned with melody, and here again, according to Helmholtz, it

is intelligible why the notes of our musical scale are used. The ear analyses all sounds into their component

"simple vibrations," although we are not conscious of this analysis. In a musical note the lowest in pitch of

these is generally predominant, and the others which are less marked are the octave, the twelfth, the second

octave, etc., all harmonies of the fundamental predominant note; any two notes of our scale have many of

these harmonic overtones in common. It seems pretty clear then, that if an animal always wished to sing

precisely the same song, he would guide himself by sounding those notes in succession, which possess many

over tones in commonthat is, he would choose for his song, notes which belong to our musical scale.

But if it be further asked why musical tones in a certain order and rhythm give man and other animals

pleasure, we can no more give the reason than for the pleasantness of certain tastes and smells. That they do

give pleasure of some kind to animals, we may infer from their being produced during the season of courtship

by many insects, spiders, fishes, amphibians, and birds; for unless the females were able to appreciate such

sounds and were excited or charmed by them, the persevering efforts of the males, and the complex structures

often possessed by them alone, would be useless; and this it is impossible to believe.

Human song is generally admitted to be the basis or origin of instrumental music. As neither the enjoyment

nor the capacity of producing musical notes are faculties of the least use to man in reference to his daily

habits of life, they must be ranked amongst the most mysterious with which he is endowed. They are present,

though in a very rude condition, in men of all races, even the most savage; but so different is the taste of the

several races, that our music gives no pleasure to savages, and their music is to us in most cases hideous and

unmeaning. Dr. Seemann, in some interesting remarks on this subject (35. 'Journal of Anthropological

Society,' Oct. 1870, p. clv. See also the several later chapters in Sir John Lubbock's 'Prehistoric Times,' 2nd

ed. 1869, which contain an admirable account of the habits of savages.), "doubts whether even amongst the

nations of Western Europe, intimately connected as they are by close and frequent intercourse, the music of

the one is interpreted in the same sense by the others. By travelling eastwards we find that there is certainly a

different language of music. Songs of joy and dance accompaniments are no longer, as with us, in the major

keys, but always in the minor." Whether or not the halfhuman progenitors of man possessed, like the

singing gibbons, the capacity of producing, and therefore no doubt of appreciating, musical notes, we know

that man possessed these faculties at a very remote period. M. Lartet has described two flutes made out of the

bones and horns of the reindeer, found in caves together with flint tools and the remains of extinct animals.

The arts of singing and of dancing are also very ancient, and are now practised by all or nearly all the lowest

races of man. Poetry, which may be considered as the offspring of song, is likewise so ancient, that many

persons have felt astonished that it should have arisen during the earliest ages of which we have any record.

We see that the musical faculties, which are not wholly deficient in any race, are capable of prompt and high

development, for Hottentots and Negroes have become excellent musicians, although in their native countries

they rarely practise anything that we should consider music. Schweinfurth, however, was pleased with some

of the simple melodies which he heard in the interior of Africa. But there is nothing anomalous in the musical

faculties lying dormant in man: some species of birds which never naturally sing, can without much difficulty

be taught to do so; thus a housesparrow has learnt the song of a linnet. As these two species are closely

allied, and belong to the order of Insessores, which includes nearly all the singingbirds in the world, it is

possible that a progenitor of the sparrow may have been a songster. It is more remarkable that parrots,

belonging to a group distinct from the Insessores, and having differently constructed vocal organs, can be

taught not only to speak, but to pipe or whistle tunes invented by man, so that they must have some musical

capacity. Nevertheless it would be very rash to assume that parrots are descended from some ancient form

which was a songster. Many cases could be advanced of organs and instincts originally adapted for one

purpose, having been utilised for some distinct purpose. (36. Since this chapter was printed, I have seen a

valuable article by Mr. Chauncey Wright ('North American Review,' Oct. 1870, page 293), who, in

discussing the above subject, remarks, "There are many consequences of the ultimate laws or uniformities of

nature, through which the acquisition of one useful power will bring with it many resulting advantages as

well as limiting disadvantages, actual or possible, which the principle of utility may not have comprehended

in its action." As I have attempted to shew in an early chapter of this work, this principle has an important

bearing on the acquisition by man of some of his mental characteristics.) Hence the capacity for high musical

development which the savage races of man possess, may be due either to the practice by our semihuman

progenitors of some rude form of music, or simply to their having acquired the proper vocal organs for a

different purpose. But in this latter case we must assume, as in the above instance of parrots, and as seems to

Music arouses in us various emotions, but not the more terrible ones of horror, fear, rage, etc. It awakens the

gentler feelings of tenderness and love, which readily pass into devotion. In the Chinese annals it is said,

"Music hath the power of making heaven descend upon earth." It likewise stirs up in us the sense of triumph

and the glorious ardour for war. These powerful and mingled feelings may well give rise to the sense of

sublimity. We can concentrate, as Dr. Seemann observes, greater intensity of feeling in a single musical note

than in pages of writing. It is probable that nearly the same emotions, but much weaker and far less complex,

are felt by birds when the male pours forth his full volume of song, in rivalry with other males, to captivate

the female. Love is still the commonest theme of our songs. As Herbert Spencer remarks, "music arouses

dormant sentiments of which we had not conceived the possibility, and do not know the meaning; or, as

Richter says, tells us of things we have not seen and shall not see." Conversely, when vivid emotions are felt

and expressed by the orator, or even in common speech, musical cadences and rhythm are instinctively used.

The negro in Africa when excited often bursts forth in song; "another will reply in song, whilst the company,

as if touched by a musical wave, murmur a chorus in perfect unison." (37. Winwood Reade, 'The Martyrdom

of Man,' 1872, p. 441, and 'African Sketch Book,' 1873, vol. ii. p. 313.) Even monkeys express strong

feelings in different tones anger and impatience by low,fear and pain by high notes. (38. Rengger,

'Saugethiere von Paraguay,' s. 49.) The sensations and ideas thus excited in us by music, or expressed by the

cadences of oratory, appear from their vagueness, yet depth, like mental reversions to the emotions and

All these facts with respect to music and impassioned speech become intelligible to a certain extent, if we

may assume that musical tones and rhythm were used by our halfhuman ancestors, during the season of

courtship, when animals of all kinds are excited not only by love, but by the strong passions of jealousy,

rivalry, and triumph. From the deeply laid principle of inherited associations, musical tones in this case

would be likely to call up vaguely and indefinitely the strong emotions of a longpast age. As we have every

reason to suppose that articulate speech is one of the latest, as it certainly is the highest, of the arts acquired

by man, and as the instinctive power of producing musical notes and rhythms is developed low down in the

animal series, it would be altogether opposed to the principle of evolution, if we were to admit that man's

musical capacity has been developed from the tones used in impassioned speech. We must suppose that the

rhythms and cadences of oratory are derived from previously developed musical powers. (39. See the very

interesting discussion on the 'Origin and Function of Music,' by Mr. Herbert Spencer, in his collected

'Essays,' 1858, p. 359. Mr. Spencer comes to an exactly opposite conclusion to that at which I have arrived.

He concludes, as did Diderot formerly, that the cadences used in emotional speech afford the foundation from

which music has been developed; whilst I conclude that musical notes and rhythm were first acquired by the

male or female progenitors of mankind for the sake of charming the opposite sex. Thus musical tones became

firmly associated with some of the strongest passions an animal is capable of feeling, and are consequently

used instinctively, or through association when strong emotions are expressed in speech. Mr. Spencer does

not offer any satisfactory explanation, nor can I, why high or deep notes should be expressive, both with man

and the lower animals, of certain emotions. Mr. Spencer gives also an interesting discussion on the relations

between poetry, recitative and song.) We can thus understand how it is that music, dancing, song, and poetry

are such very ancient arts. We may go even further than this, and, as remarked in a former chapter, believe

that musical sounds afforded one of the bases for the development of language. (40. I find in Lord

Monboddo's 'Origin of Language,' vol. i. 1774, p. 469, that Dr. Blacklock likewise thought "that the first

language among men was music, and that before our ideas were expressed by articulate sounds, they were

communicated by tones varied according to different degrees of gravity and acuteness.")

As the males of several quadrumanous animals have their vocal organs much more developed than in the

females, and as a gibbon, one of the anthropomorphous apes, pours forth a whole octave of musical notes and

may be said to sing, it appears probable that the progenitors of man, either the males or females or both sexes,

before acquiring the power of expressing their mutual love in articulate language, endeavoured to charm each

other with musical notes and rhythm. So little is known about the use of the voice by the Quadrumana during

the season of love, that we have no means of judging whether the habit of singing was first acquired by our

male or female ancestors. Women are generally thought to possess sweeter voices than men, and as far as this

serves as any guide, we may infer that they first acquired musical powers in order to attract the other sex. (41.

See an interesting discussion on this subject by Haeckel, 'Generelle Morphologie,' B. ii. 1866, s. 246.) But if

so, this must have occurred long ago, before our ancestors had become sufficiently human to treat and value

their women merely as useful slaves. The impassioned orator, bard, or musician, when with his varied tones

and cadences he excites the strongest emotions in his hearers, little suspects that he uses the same means by

which his halfhuman ancestors long ago aroused each other's ardent passions, during their courtship and

In civilised life man is largely, but by no means exclusively, influenced in the choice of his wife by external

appearance; but we are chiefly concerned with primeval times, and our only means of forming a judgment on

this subject is to study the habits of existing semicivilised and savage nations. If it can be shewn that the

men of different races prefer women having various characteristics, or conversely with the women, we have

then to enquire whether such choice, continued during many generations, would produce any sensible effect

on the race, either on one sex or both according to the form of inheritance which has prevailed.

It will be well first to shew in some detail that savages pay the greatest attention to their personal appearance.

(42. A full and excellent account of the manner in which savages in all parts of the world ornament

themselves, is given by the Italian traveller, Professor Mantegazza, 'Rio de la Plata, Viaggi e Studi,' 1867, pp.

525545; all the following statements, when other references are not given, are taken from this work. See,

also, Waitz, 'Introduction to Anthropology,' Eng. translat. vol. i. 1863, p. 275, et passim. Lawrence also gives

very full details in his 'Lectures on Physiology,' 1822. Since this chapter was written Sir J. Lubbock has

published his 'Origin of Civilisation,' 1870, in which there is an interesting chapter on the present subject, and

from which (pp. 42, 48) I have taken some facts about savages dyeing their teeth and hair, and piercing their

teeth.) That they have a passion for ornament is notorious; and an English philosopher goes so far as to

maintain, that clothes were first made for ornament and not for warmth. As Professor Waitz remarks,

"however poor and miserable man is, he finds a pleasure in adorning himself." The extravagance of the naked

Indians of South America in decorating themselves is shewn "by a man of large stature gaining with

difficulty enough by the labour of a fortnight to procure in exchange the chica necessary to paint himself

red." (43. Humboldt, 'Personal Narrative,' Eng. translat. vol. iv. p. 515; on the imagination shewn in painting

the body, p. 522; on modifying the form of the calf of the leg, p. 466.) The ancient barbarians of Europe

during the Reindeer period brought to their caves any brilliant or singular objects which they happened to

find. Savages at the present day everywhere deck themselves with plumes, necklaces, armlets, earrings, etc.

They paint themselves in the most diversified manner. "If painted nations," as Humboldt observes, "had been

examined with the same attention as clothed nations, it would have been perceived that the most fertile

imagination and the most mutable caprice have created the fashions of painting, as well as those of

In one part of Africa the eyelids are coloured black; in another the nails are coloured yellow or purple. In

many places the hair is dyed of various tints. In different countries the teeth are stained black, red, blue, etc.,

and in the Malay Archipelago it is thought shameful to have white teeth "like those of a dog." Not one great

country can be named, from the polar regions in the north to New Zealand in the south, in which the

aborigines do not tattoo themselves. This practice was followed by the Jews of old, and by the ancient

Britons. In Africa some of the natives tattoo themselves, but it is a much more common practice to raise

protuberances by rubbing salt into incisions made in various parts of the body; and these are considered by

the inhabitants of Kordofan and Darfur "to be great personal attractions." In the Arab countries no beauty can

be perfect until the cheeks "or temples have been gashed." (44. 'The Nile Tributaries,' 1867; 'The Albert

N'yanza,' 1866, vol. i. p. 218.) In South America, as Humboldt remarks, "a mother would be accused of

culpable indifference towards her children, if she did not employ artificial means to shape the calf of the leg

after the fashion of the country." In the Old and New Worlds the shape of the skull was formerly modified

during infancy in the most extraordinary manner, as is still the case in many places, and such deformities are

considered ornamental. For instance, the savages of Colombia (45. Quoted by Prichard, 'Physical History of

Mankind,' 4th ed. vol. i. 1851, p. 321.) deem a much flattened head "an essential point of beauty."

The hair is treated with especial care in various countries; it is allowed to grow to full length, so as to reach to

the ground, or is combed into "a compact frizzled mop, which is the Papuan's pride and glory." (46. On the

Papuans, Wallace, 'The Malay Archipelago,' vol. ii. p. 445. On the coiffure of the Africans, Sir S. Baker, 'The

Albert N'yanza,' vol. i. p. 210.) In northern Africa "a man requires a period of from eight to ten years to

perfect his coiffure." With other nations the head is shaved, and in parts of South America and Africa even

the eyebrows and eyelashes are eradicated. The natives of the Upper Nile knock out the four front teeth,

saying that they do not wish to resemble brutes. Further south, the Batokas knock out only the two upper

incisors, which, as Livingstone (47. 'Travels,' p. 533.) remarks, gives the face a hideous appearance, owing to

the prominence of the lower jaw; but these people think the presence of the incisors most unsightly, and on

beholding some Europeans, cried out, "Look at the great teeth!" The chief Sebituani tried in vain to alter this

fashion. In various parts of Africa and in the Malay Archipelago the natives file the incisors into points like

As the face with us is chiefly admired for its beauty, so with savages it is the chief seat of mutilation. In all

quarters of the world the septum, and more rarely the wings of the nose are pierced; rings, sticks, feathers,

and other ornaments being inserted into the holes. The ears are everywhere pierced and similarly ornamented,

and with the Botocudos and Lenguas of South America the hole is gradually so much enlarged that the lower

edge touches the shoulder. In North and South America and in Africa either the upper or lower lip is pierced;

and with the Botocudos the hole in the lower lip is so large that a disc of wood, four inches in diameter, is

placed in it. Mantegazza gives a curious account of the shame felt by a South American native, and of the

ridicule which he excited, when he sold his tembeta,the large coloured piece of wood which is passed

through the hole. In Central Africa the women perforate the lower lip and wear a crystal, which, from the

movement of the tongue, has "a wriggling motion, indescribably ludicrous during conversation." The wife of

the chief of Latooka told Sir S. Baker (49. 'The Albert N'yanza,' 1866, vol. i. p. 217.) that Lady Baker "would

be much improved if she would extract her four front teeth from the lower jaw, and wear the long pointed

polished crystal in her under lip." Further south with the Makalolo, the upper lip is perforated, and a large

metal and bamboo ring, called a pelele, is worn in the hole. "This caused the lip in one case to project two

inches beyond the tip of the nose; and when the lady smiled, the contraction of the muscles elevated it over

the eyes. 'Why do the women wear these things?' the venerable chief, Chinsurdi, was asked. Evidently

surprised at such a stupid question, he replied, 'For beauty! They are the only beautiful things women have;

men have beards, women have none. What kind of a person would she be without the pelele? She would not

be a woman at all with a mouth like a man, but no beard.'" (49. Livingstone, 'British Association,' 1860;

Hardly any part of the body, which can be unnaturally modified, has escaped. The amount of suffering thus

caused must have been extreme, for many of the operations require several years for their completion, so that

the idea of their necessity must be imperative. The motives are various; the men paint their bodies to make

themselves appear terrible in battle; certain mutilations are connected with religious rites, or they mark the

age of puberty, or the rank of the man, or they serve to distinguish the tribes. Amongst savages the same

fashions prevail for long periods (50. Sir S. Baker (ibid. vol. i. p. 210) speaking of the natives of Central

Africa says, "every tribe has a distinct and unchanging fashion for dressing the hair." See Agassiz ('Journey in

Brazil,' 1868, p. 318) on invariability of the tattooing of Amazonian Indians.), and thus mutilations, from

whatever cause first made, soon come to be valued as distinctive marks. But selfadornment, vanity, and the

admiration of others, seem to be the commonest motives. In regard to tattooing, I was told by the

missionaries in New Zealand that when they tried to persuade some girls to give up the practice, they

answered, "We must just have a few lines on our lips; else when we grow old we shall be so very ugly." With

the men of New Zealand, a most capable judge (51. Rev. R. Taylor, 'New Zealand and its Inhabitants,' 1855,

p. 152.) says, "to have fine tattooed faces was the great ambition of the young, both to render themselves

attractive to the ladies, and conspicuous in war." A star tattooed on the forehead and a spot on the chin are

thought by the women in one part of Africa to be irresistible attractions. (52. Mantegazza, 'Viaggi e Studi,' p.

542.) In most, but not all parts of the world, the men are more ornamented than the women, and often in a

different manner; sometimes, though rarely, the women are hardly at all ornamented. As the women are made

by savages to perform the greatest share of the work, and as they are not allowed to eat the best kinds of food,

so it accords with the characteristic selfishness of man that they should not be allowed to obtain, or use the

finest ornaments. Lastly, it is a remarkable fact, as proved by the foregoing quotations, that the same fashions

in modifying the shape of the head, in ornamenting the hair, in painting, tattooing, in perforating the nose,

lips, or ears, in removing or filing the teeth, etc., now prevail, and have long prevailed, in the most distant

quarters of the world. It is extremely improbable that these practices, followed by so many distinct nations,

should be due to tradition from any common source. They indicate the close similarity of the mind of man, to

whatever race he may belong, just as do the almost universal habits of dancing, masquerading, and making

Having made these preliminary remarks on the admiration felt by savages for various ornaments, and for

deformities most unsightly in our eyes, let us see how far the men are attracted by the appearance of their

women, and what are their ideas of beauty. I have heard it maintained that savages are quite indifferent about

the beauty of their women, valuing them solely as slaves; it may therefore be well to observe that this

conclusion does not at all agree with the care which the women take in ornamenting themselves, or with their

vanity. Burchell (53. 'Travels in South Africa,' 1824, vol. i. p. 414.) gives an amusing account of a

Bushwoman who used as much grease, red ochre, and shining powder "as would have ruined any but a very

rich husband." She displayed also "much vanity and too evident a consciousness of her superiority." Mr.

Winwood Reade informs me that the negroes of the West Coast often discuss the beauty of their women.

Some competent observers have attributed the fearfully common practice of infanticide partly to the desire

felt by the women to retain their good looks. (54. See, for references, Gerland, 'Ueber das Aussterben der

Naturvolker,' 1868, ss. 51, 53, 55; also Azara, 'Voyages,' etc., tom. ii. p. 116.) In several regions the women

wear charms and use lovephilters to gain the affections of the men; and Mr. Brown enumerates four plants

used for this purpose by the women of NorthWestern America. (55. On the vegetable productions used by

Hearne (56. 'A Journey from Prince of Wales Fort,' 8vo. ed. 1796, p. 89.), an excellent observer, who lived

many years with the American Indians, says, in speaking of the women, "Ask a Northern Indian what is

beauty, and he will answer, a broad flat face, small eyes, high cheekbones, three or four broad black lines

across each cheek, a low forehead, a large broad chin, a clumsy hook nose, a tawny hide, and breasts hanging

down to the belt." Pallas, who visited the northern parts of the Chinese empire, says, "those women are

preferred who have the Mandschu form; that is to say, a broad face, high cheekbones, very broad noses, and

enormous ears"(57. Quoted by Prichard, 'Physical History of Mankind,' 3rd ed. vol. iv. 1844, p. 519; Vogt,

'Lectures on Man,' Eng. translat. p. 129. On the opinion of the Chinese on the Cingalese, E. Tennent, 'Ceylon,'

1859, vol. ii. p. 107.); and Vogt remarks that the obliquity of the eye, which is proper to the Chinese and

Japanese, is exaggerated in their pictures for the purpose, as it "seems, of exhibiting its beauty, as contrasted

with the eye of the redhaired barbarians." It is well known, as Huc repeatedly remarks, that the Chinese of

the interior think Europeans hideous, with their white skins and prominent noses. The nose is far from being

too prominent, according to our ideas, in the natives of Ceylon; yet "the Chinese in the seventh century,

accustomed to the flat features of the Mongol races, were surprised at the prominent noses of the Cingalese;

and Thsang described them as having 'the beak of a bird, with the body of a man.'"

Finlayson, after minutely describing the people of Cochin China, says that their rounded heads and faces are

their chief characteristics; and, he adds, "the roundness of the whole countenance is more striking in the

women, who are reckoned beautiful in proportion as they display this form of face." The Siamese have small

noses with divergent nostrils, a wide mouth, rather thick lips, a remarkably large face, with very high and

broad cheekbones. It is, therefore, not wonderful that "beauty, according to our notion, is a stranger to them.

Yet they consider their own females to be much more beautiful than those of Europe." (58. Prichard, as taken

It is well known that with many Hottentot women the posterior part of the body projects in a wonderful

manner; they are steatopygous; and Sir Andrew Smith is certain that this peculiarity is greatly admired by the

men. (59. Idem illustrissimus viator dixit mihi praecinctorium vel tabulam foeminae, quod nobis teterrimum

est, quondam permagno aestimari ab hominibus in hac gente. Nunc res mutata est, et censent talem

conformationem minime optandam esse.) He once saw a woman who was considered a beauty, and she was

so immensely developed behind, that when seated on level ground she could not rise, and had to push herself

along until she came to a slope. Some of the women in various negro tribes have the same peculiarity; and,

according to Burton, the Somal men are said to choose their wives by ranging them in a line, and by picking

her out who projects farthest a tergo. Nothing can be more hateful to a negro than the opposite form." (60.

The 'Anthropological Review,' November 1864, p. 237. For additional references, see Waitz, 'Introduction to

With respect to colour, the negroes rallied Mungo Park on the whiteness of his skin and the prominence of his

nose, both of which they considered as "unsightly and unnatural conformations." He in return praised the

glossy jet of their skins and the lovely depression of their noses; this they said was "honeymouth,"

nevertheless they gave him food. The African Moors, also, "knitted their brows and seemed to shudder" at the

whiteness of his skin. On the eastern coast, the negro boys when they saw Burton, cried out, "Look at the

white man; does he not look like a white ape?" On the western coast, as Mr. Winwood Reade informs me, the

negroes admire a very black skin more than one of a lighter tint. But their horror of whiteness may be

attributed, according to this same traveller, partly to the belief held by most negroes that demons and spirits

The Banyai of the more southern part of the continent are negroes, but "a great many of them are of a light

coffeeandmilk colour, and, indeed, this colour is considered handsome throughout the whole country"; so

that here we have a different standard of taste. With the Kaffirs, who differ much from negroes, "the skin,

except among the tribes near Delagoa Bay, is not usually black, the prevailing colour being a mixture of

black and red, the most common shade being chocolate. Dark complexions, as being most common, are

naturally held in the highest esteem. To be told that he is light coloured, or like a white man, would be

deemed a very poor compliment by a Kaffir. I have heard of one unfortunate man who was so very fair that

no girl would marry him." One of the titles of the Zulu king is, "You who are black." (61. Mungo Park's

'Travels in Africa,' 4to. 1816, pp. 53, 131. Burton's statement is quoted by Schaaffhausen, 'Archiv. fur

Anthropologie,' 1866, s. 163. On the Banyai, Livingstone, 'Travels,' p. 64. On the Kaffirs, the Rev. J. Shooter,

'The Kafirs of Natal and the Zulu Country,' 1857, p. 1.) Mr. Galton, in speaking to me about the natives of S.

Africa, remarked that their ideas of beauty seem very different from ours; for in one tribe two slim, slight,

Turning to other quarters of the world; in Java, a yellow, not a white girl, is considered, according to Madame

Pfeiffer, a beauty. A man of Cochin China "spoke with contempt of the wife of the English Ambassador, that

she had white teeth like a dog, and a rosy colour like that of potato flowers." We have seen that the Chinese

dislike our white skin, and that the N. Americans admire "a tawny hide." In S. America, the Yuracaras, who

inhabit the wooded, damp slopes of the eastern Cordillera, are remarkably palecoloured, as their name in

their own language expresses; nevertheless they consider European women as very inferior to their own. (62.

For the Javans and CochinChinese, see Waitz, 'Introduct. to Anthropology,' Eng. translat. vol. i. p. 305. On

the Yuracaras, A. d'Orbigny, as quoted in Prichard, 'Physical History of Mankind,' vol. v. 3rd ed. p. 476.)

In several of the tribes of North America the hair on the head grows to a wonderful length; and Catlin gives a

curious proof how much this is esteemed, for the chief of the Crows was elected to this office from having the

longest hair of any man in the tribe, namely ten feet and seven inches. The Aymaras and Quichuas of S.

America, likewise have very long hair; and this, as Mr. D. Forbes informs me, is so much valued as a beauty,

that cutting it off was the severest punishment which he could inflict on them. In both the Northern and

Southern halves of the continent the natives sometimes increase the apparent length of their hair by weaving

into it fibrous substances. Although the hair on the head is thus cherished, that on the face is considered by

the North American Indians "as very vulgar," and every hair is carefully eradicated. This practice prevails

throughout the American continent from Vancouver's Island in the north to Tierra del Fuego in the south.

When York Minster, a Fuegian on board the "Beagle," was taken back to his country, the natives told him be

ought to pull out the few short hairs on his face. They also threatened a young missionary, who was left for a

time with them, to strip him naked, and pluck the hair from his face and body, yet he was far from being a

hairy man. This fashion is carried so far that the Indians of Paraguay eradicate their eyebrows and eyelashes,

saying that they do not wish to be like horses. (63. 'North American Indians,' by G. Catlin, 3rd ed., 1842, vol.

i. p. 49; vol. ii, p. 227. On the natives of Vancouver's Island, see Sproat, 'Scenes and Studies of Savage Life,'

It is remarkable that throughout the world the races which are almost completely destitute of a beard dislike

hairs on the face and body, and take pains to eradicate them. The Kalmucks are beardless, and they are well

known, like the Americans, to pluck out all straggling hairs; and so it is with the Polynesians, some of the

Malays, and the Siamese. Mr. Veitch states that the Japanese ladies "all objected to our whiskers, considering

them very ugly, and told us to cut them off, and be like Japanese men." The New Zealanders have short,

curled beards; yet they formerly plucked out the hairs on the face. They had a saying that "there is no woman

for a hairy man;" but it would appear that the fashion has changed in New Zealand, perhaps owing to the

presence of Europeans, and I am assured that beards are now admired by the Maories. (64. On the Siamese,

Prichard, ibid. vol. iv. p. 533. On the Japanese, Veitch in 'Gardeners' Chronicle,' 1860, p. 1104. On the New

Zealanders, Mantegazza, 'Viaggi e Studi,' 1867, p. 526. For the other nations mentioned, see references in

On the other hand, bearded races admire and greatly value their beards; among the AngloSaxons every part

of the body had a recognised value; "the loss of the beard being estimated at twenty shillings, while the

breaking of a thigh was fixed at only twelve." (65. Lubbock, 'Origin of Civilisation,' 1870, p. 321.) In the East

men swear solemnly by their beards. We have seen that Chinsurdi, the chief of the Makalolo in Africa,

thought that beards were a great ornament. In the Pacific the Fijian's beard is "profuse and bushy, and is his

greatest pride"; whilst the inhabitants of the adjacent archipelagoes of Tonga and Samoa are "beardless, and

abhor a rough chin." In one island alone of the Ellice group "the men are heavily bearded, and not a little

proud thereof." (66. Dr. Barnard Davis quotes Mr. Prichard and others for these facts in regard to the

We thus see how widely the different races of man differ in their taste for the beautiful. In every nation

sufficiently advanced to have made effigies of their gods or of their deified rulers, the sculptors no doubt have

endeavoured to express their highest ideal of beauty and grandeur. (67. Ch. Comte has remarks to this effect

in his 'Traite de Legislation,' 3rd ed. 1837, p. 136.) Under this point of view it is well to compare in our mind

the Jupiter or Apollo of the Greeks with the Egyptian or Assyrian statues; and these with the hideous

I have met with very few statements opposed to this conclusion. Mr. Winwood Reade, however, who has had

ample opportunities for observation, not only with the negroes of the West Coast of Africa, but with those of

the interior who have never associated with Europeans, is convinced that their ideas of beauty are ON THE

WHOLE the same as ours; and Dr. Rohlfs writes to me to the same effect with respect to Bornu and the

countries inhabited by the Pullo tribes. Mr. Reade found that he agreed with the negroes in their estimation of

the beauty of the native girls; and that their appreciation of the beauty of European women corresponded with

ours. They admire long hair, and use artificial means to make it appear abundant; they admire also a beard,

though themselves very scantily provided. Mr. Reade feels doubtful what kind of nose is most appreciated; a

girl has been heard to say, "I do not want to marry him, he has got no nose"; and this shews that a very flat

nose is not admired. We should, however, bear in mind that the depressed, broad noses and projecting jaws of

the negroes of the West Coast are exceptional types with the inhabitants of Africa. Notwithstanding the

foregoing statements, Mr. Reade admits that negroes "do not like the colour of our skin; they look on blue

eyes with aversion, and they think our noses too long and our lips too thin." He does not think it probable that

negroes would ever prefer the most beautiful European woman, on the mere grounds of physical admiration,

to a goodlooking negress. (68. The 'African Sketch Book,' vol. ii. 1873, pp. 253, 394, 521. The Fuegians, as

I have been informed by a missionary who long resided with them, consider European women as extremely

beautiful; but from what we have seen of the judgment of the other aborigines of America, I cannot but think

that this must be a mistake, unless indeed the statement refers to the few Fuegians who have lived for some

time with Europeans, and who must consider us as superior beings. I should add that a most experienced

observer, Capt. Burton, believes that a woman whom we consider beautiful is admired throughout the world.

The general truth of the principle, long ago insisted on by Humboldt (69. 'Personal Narrative,' Eng. translat.

vol. iv. p. 518, and elsewhere. Mantegazza, in his 'Viaggi e Studi,' strongly insists on this same principle.),

that man admires and often tries to exaggerate whatever characters nature may have given him, is shewn in

many ways. The practice of beardless races extirpating every trace of a beard, and often all the hairs on the

body affords one illustration. The skull has been greatly modified during ancient and modern times by many

nations; and there can be little doubt that this has been practised, especially in N. and S. America, in order to

exaggerate some natural and admired peculiarity. Many American Indians are known to admire a head so

extremely flattened as to appear to us idiotic. The natives on the northwestern coast compress the head into

a pointed cone; and it is their constant practice to gather the hair into a knot on the top of the head, for the

sake, as Dr. Wilson remarks, "of increasing the apparent elevation of the favourite conoid form." The

inhabitants of Arakhan admire a broad, smooth forehead, and in order to produce it, they fasten a plate of lead

on the heads of the newborn children. On the other hand, "a broad, wellrounded occiput is considered a

great beauty" by the natives of the Fiji Islands. (70. On the skulls of the American tribes, see Nott and

Gliddon, 'Types of Mankind,' 1854, p. 440; Prichard, 'Physical History of Mankind,' vol. i. 3rd ed. p. 321; on

the natives of Arakhan, ibid. vol. iv. p. 537. Wilson, 'Physical Ethnology,' Smithsonian Institution, 1863, p.

288; on the Fijians, p. 290. Sir J. Lubbock ('Prehistoric Times,' 2nd ed. 1869, p. 506) gives an excellent

As with the skull, so with the nose; the ancient Huns during the age of Attila were accustomed to flatten the

noses of their infants with bandages, "for the sake of exaggerating a natural conformation." With the

Tahitians, to be called LONGNOSE is considered as an insult, and they compress the noses and foreheads

of their children for the sake of beauty. The same holds with the Malays of Sumatra, the Hottentots, certain

Negroes, and the natives of Brazil. (71. On the Huns, Godron, 'De l'Espece,' tom. ii. 1859, p. 300. On the

Tahitians, Waitz, 'Anthropology,' Eng. translat. vol. i. p. 305. Marsden, quoted by Prichard, 'Phys. Hist. of

Mankind,' 3rd edit. vol. v. p. 67. Lawrence, 'Lectures on Physiology,' p. 337.) The Chinese have by nature

unusually small feet (72. This fact was ascertained in the 'Reise der Novara: Anthropolog. Theil.' Dr.

Weisbach, 1867, s. 265.); and it is well known that the women of the upper classes distort their feet to make

them still smaller. Lastly, Humboldt thinks that the American Indians prefer colouring their bodies with red

paint in order to exaggerate their natural tint; and until recently European women added to their naturally

bright colours by rouge and white cosmetics; but it may be doubted whether barbarous nations have generally

In the fashions of our own dress we see exactly the same principle and the same desire to carry every point to

an extreme; we exhibit, also, the same spirit of emulation. But the fashions of savages are far more permanent

than ours; and whenever their bodies are artificially modified, this is necessarily the case. The Arab women

of the Upper Nile occupy about three days in dressing their hair; they never imitate other tribes, "but simply

vie with each other in the superlativeness of their own style." Dr. Wilson, in speaking of the compressed

skulls of various American races, adds, "such usages are among the least eradicable, and long survive the

shock of revolutions that change dynasties and efface more important national peculiarities." (73.

'Smithsonian Institution,' 1863, p. 289. On the fashions of Arab women, Sir S. Baker, 'The Nile Tributaries,'

1867, p. 121.) The same principle comes into play in the art of breeding; and we can thus understand, as I

have elsewhere explained (74. The 'Variation of Animals and Plants under Domestication,' vol. i. p. 214; vol.

ii. p. 240.), the wonderful development of the many races of animals and plants, which have been kept merely

for ornament. Fanciers always wish each character to be somewhat increased; they do not admire a medium

standard; they certainly do not desire any great and abrupt change in the character of their breeds; they

admire solely what they are accustomed to, but they ardently desire to see each characteristic feature a little

The senses of man and of the lower animals seem to be so constituted that brilliant colours and certain forms,

as well as harmonious and rhythmical sounds, give pleasure and are called beautiful; but why this should be

so we know not. It is certainly not true that there is in the mind of man any universal standard of beauty with

respect to the human body. It is, however, possible that certain tastes may in the course of time become

inherited, though there is no evidence in favour of this belief: and if so, each race would possess its own

innate ideal standard of beauty. It has been argued (75. Schaaffhausen, 'Archiv. fur Anthropologie,' 1866, s.

164.) that ugliness consists in an approach to the structure of the lower animals, and no doubt this is partly

true with the more civilised nations, in which intellect is highly appreciated; but this explanation will hardly

apply to all forms of ugliness. The men of each race prefer what they are accustomed to; they cannot endure

any great change; but they like variety, and admire each characteristic carried to a moderate extreme. (76. Mr.

Bain has collected ('Mental and Moral Science,' 1868, pp. 304314) about a dozen more or less different

theories of the idea of beauty; but none is quite the same as that here given.) Men accustomed to a nearly oval

face, to straight and regular features, and to bright colours, admire, as we Europeans know, these points when

strongly developed. On the other hand, men accustomed to a broad face, with high cheekbones, a depressed

nose, and a black skin, admire these peculiarities when strongly marked. No doubt characters of all kinds may

be too much developed for beauty. Hence a perfect beauty, which implies many characters modified in a

particular manner, will be in every race a prodigy. As the great anatomist Bichat long ago said, if every one

were cast in the same mould, there would be no such thing as beauty. If all our women were to become as

beautiful as the Venus de' Medici, we should for a time be charmed; but we should soon wish for variety; and

as soon as we had obtained variety, we should wish to see certain characters a little exaggerated beyond the

On the effects of the continued selection of women according to a different standard of beauty in each

raceOn the causes which interfere with sexual selection in civilised and savage nationsConditions

favourable to sexual selection during primeval timesOn the manner of action of sexual selection with

mankindOn the women in savage tribes having some power to choose their husbandsAbsence of hair on

We have seen in the last chapter that with all barbarous races ornaments, dress, and external appearance are

highly valued; and that the men judge of the beauty of their women by widely different standards. We must

next inquire whether this preference and the consequent selection during many generations of those women,

which appear to the men of each race the most attractive, has altered the character either of the females alone,

or of both sexes. With mammals the general rule appears to be that characters of all kinds are inherited

equally by the males and females; we might therefore expect that with mankind any characters gained by the

females or by the males through sexual selection would commonly be transferred to the offspring of both

sexes. If any change has thus been effected, it is almost certain that the different races would be differently

With mankind, especially with savages, many causes interfere with the action of sexual selection as far as the

bodily frame is concerned. Civilised men are largely attracted by the mental charms of women, by their

wealth, and especially by their social position; for men rarely marry into a much lower rank. The men who

succeed in obtaining the more beautiful women will not have a better chance of leaving a long line of

descendants than other men with plainer wives, save the few who bequeath their fortunes according to

primogeniture. With respect to the opposite form of selection, namely, of the more attractive men by the

women, although in civilised nations women have free or almost free choice, which is not the case with

barbarous races, yet their choice is largely influenced by the social position and wealth of the men; and the

success of the latter in life depends much on their intellectual powers and energy, or on the fruits of these

same powers in their forefathers. No excuse is needed for treating this subject in some detail; for, as the

German philosopher Schopenhauer remarks, "the final aim of all love intrigues, be they comic or tragic, is

really of more importance than all other ends in human life. What it all turns upon is nothing less than the

composition of the next generation...It is not the weal or woe of any one individual, but that of the human

race to come, which is here at stake." (1. 'Schopenhauer and Darwinism,' in 'Journal of Anthropology,' Jan.

There is, however, reason to believe that in certain civilised and semi civilised nations sexual selection has

effected something in modifying the bodily frame of some of the members. Many persons are convinced, as it

appears to me with justice, that our aristocracy, including under this term all wealthy families in which

primogeniture has long prevailed, from having chosen during many generations from all classes the more

beautiful women as their wives, have become handsomer, according to the European standard, than the

middle classes; yet the middle classes are placed under equally favourable conditions of life for the perfect

development of the body. Cook remarks that the superiority in personal appearance "which is observable in

the erees or nobles in all the other islands (of the Pacific) is found in the Sandwich Islands"; but this may be

The old traveller Chardin, in describing the Persians, says their "blood is now highly refined by frequent

intermixtures with the Georgians and Circassians, two nations which surpass all the world in personal beauty.

There is hardly a man of rank in Persia who is not born of a Georgian or Circassian mother." He adds that

they inherit their beauty, "not from their ancestors, for without the above mixture, the men of rank in Persia,

who are descendants of the Tartars, would be extremely ugly." (2. These quotations are taken from Lawrence

('Lectures on Physiology,' etc., 1822, p. 393), who attributes the beauty of the upper classes in England to the

men having long selected the more beautiful women.) Here is a more curious case; the priestesses who

attended the temple of Venus Erycina at San Giuliano in Sicily, were selected for their beauty out of the

whole of Greece; they were not vestal virgins, and Quatrefages (3. 'Anthropologie,' 'Revue des Cours

Scientifiques,' Oct. 1868, p. 721.), who states the foregoing fact, says that the women of SanGiuliano are

now famous as the most beautiful in the island, and are sought by artists as models. But it is obvious that the

The following case, though relating to savages, is well worth giving for its curiosity. Mr. Winwood Reade

informs me that the Jollofs, a tribe of negroes on the west coast of Africa, "are remarkable for their uniformly

fine appearance." A friend of his asked one of these men, "How is it that every one whom I meet is so fine

looking, not only your men but your women?" The Jollof answered, "It is very easily explained: it has always

been our custom to pick out our worstlooking slaves and to sell them." It need hardly be added that with all

savages, female slaves serve as concubines. That this negro should have attributed, whether rightly or

wrongly, the fine appearance of his tribe to the longcontinued elimination of the ugly women is not so

surprising as it may at first appear; for I have elsewhere shewn (4. 'Variation of Animals and Plants under

Domestication,' vol. i. p. 207.) that negroes fully appreciate the importance of selection in the breeding of

their domestic animals, and I could give from Mr. Reade additional evidence on this head.

The chief causes are, first, socalled communal marriages or promiscuous intercourse; secondly, the

consequences of female infanticide; thirdly, early betrothals; and lastly, the low estimation in which women

It is obvious that as long as the pairing of man, or of any other animal, is left to mere chance, with no choice

exerted by either sex, there can be no sexual selection; and no effect will be produced on the offspring by

certain individuals having had an advantage over others in their courtship. Now it is asserted that there exist

at the present day tribes which practise what Sir J. Lubbock by courtesy calls communal marriages; that is, all

the men and women in the tribe are husbands and wives to one another. The licentiousness of many savages

is no doubt astonishing, but it seems to me that more evidence is requisite, before we fully admit that their

intercourse is in any case promiscuous. Nevertheless all those who have most closely studied the subject (5.

Sir J. Lubbock, 'The Origin of Civilisation,' 1870, chap. iii. especially pp. 6067. Mr. M'Lennan, in his

extremely valuable work on 'Primitive Marriage,' 1865, p. 163, speaks of the union of the sexes "in the

earliest times as loose, transitory, and in some degree promiscuous." Mr. M'Lennan and Sir J. Lubbock have

collected much evidence on the extreme licentiousness of savages at the present time. Mr. L.H. Morgan, in

his interesting memoir of the classificatory system of relationship. ('Proceedings of the American Academy

of Sciences,' vol. vii. Feb. 1868, p. 475), concludes that polygamy and all forms of marriage during primeval

times were essentially unknown. It appears also, from Sir J. Lubbock's work, that Bachofen likewise believes

that communal intercourse originally prevailed.), and whose judgment is worth much more than mine, believe

that communal marriage (this expression being variously guarded) was the original and universal form

throughout the world, including therein the intermarriage of brothers and sisters. The late Sir A. Smith, who

had travelled widely in S. Africa, and knew much about the habits of savages there and elsewhere, expressed

to me the strongest opinion that no race exists in which woman is considered as the property of the

community. I believe that his judgment was largely determined by what is implied by the term marriage.

Throughout the following discussion I use the term in the same sense as when naturalists speak of animals as

monogamous, meaning thereby that the male is accepted by or chooses a single female, and lives with her

either during the breedingseason or for the whole year, keeping possession of her by the law of might; or, as

when they speak of a polygamous species, meaning that the male lives with several females. This kind of

marriage is all that concerns us here, as it suffices for the work of sexual selection. But I know that some of

the writers above referred to imply by the term marriage a recognised right protected by the tribe.

The indirect evidence in favour of the belief of the former prevalence of communal marriages is strong, and

rests chiefly on the terms of relationship which are employed between the members of the same tribe,

implying a connection with the tribe, and not with either parent. But the subject is too large and complex for

even an abstract to be here given, and I will confine myself to a few remarks. It is evident in the case of such

marriages, or where the marriage tie is very loose, that the relationship of the child to its father cannot be

known. But it seems almost incredible that the relationship of the child to its mother should ever be

completely ignored, especially as the women in most savage tribes nurse their infants for a long time.

Accordingly, in many cases the lines of descent are traced through the mother alone, to the exclusion of the

father. But in other cases the terms employed express a connection with the tribe alone, to the exclusion even

of the mother. It seems possible that the connection between the related members of the same barbarous tribe,

exposed to all sorts of danger, might be so much more important, owing to the need of mutual protection and

aid, than that between the mother and her child, as to lead to the sole use of terms expressive of the former

relationships; but Mr. Morgan is convinced that this view is by no means sufficient.

The terms of relationship used in different parts of the world may be divided, according to the author just

quoted, into two great classes, the classificatory and descriptive, the latter being employed by us. It is the

classificatory system which so strongly leads to the belief that communal and other extremely loose forms of

marriage were originally universal. But as far as I can see, there is no necessity on this ground for believing

in absolutely promiscuous intercourse; and I am glad to find that this is Sir J. Lubbock's view. Men and

women, like many of the lower animals, might formerly have entered into strict though temporary unions for

each birth, and in this case nearly as much confusion would have arisen in the terms of relationship as in the

case of promiscuous intercourse. As far as sexual selection is concerned, all that is required is that choice

should be exerted before the parents unite, and it signifies little whether the unions last for life or only for a

Besides the evidence derived from the terms of relationship, other lines of reasoning indicate the former wide

prevalence of communal marriage. Sir J. Lubbock accounts for the strange and widelyextended habit of

exogamythat is, the men of one tribe taking wives from a distinct tribe,by communism having been the

original form of intercourse; so that a man never obtained a wife for himself unless he captured her from a

neighbouring and hostile tribe, and then she would naturally have become his sole and valuable property.

Thus the practice of capturing wives might have arisen; and from the honour so gained it might ultimately

have become the universal habit. According to Sir J. Lubbock (6. 'Address to British Association On the

Social and Religious Condition of the Lower Races of Man,' 1870, p. 20.), we can also thus understand "the

necessity of expiation for marriage as an infringement of tribal rites, since according to old ideas, a man had

no right to appropriate to himself that which belonged to the whole tribe." Sir J. Lubbock further gives a

curious body of facts shewing that in old times high honour was bestowed on women who were utterly

licentious; and this, as he explains, is intelligible, if we admit that promiscuous intercourse was the

aboriginal, and therefore long revered custom of the tribe. (7. 'Origin of Civilisation,' 1870, p. 86. In the

several works above quoted, there will be found copious evidence on relationship through the females alone,

Although the manner of development of the marriage tie is an obscure subject, as we may infer from the

divergent opinions on several points between the three authors who have studied it most closely, namely, Mr.

Morgan, Mr. M'Lennan, and Sir J. Lubbock, yet from the foregoing and several other lines of evidence it

seems probable (8. Mr. C. Staniland Wake argues strongly ('Anthropologia,' March, 1874, p. 197) against the

views held by these three writers on the former prevalence of almost promiscuous intercourse; and he thinks

that the classificatory system of relationship can be otherwise explained.) that the habit of marriage, in any

strict sense of the word, has been gradually developed; and that almost promiscuous or very loose intercourse

was once extremely common throughout the world. Nevertheless, from the strength of the feeling of jealousy

all through the animal kingdom, as well as from the analogy of the lower animals, more particularly of those

which come nearest to man, I cannot believe that absolutely promiscuous intercourse prevailed in times past,

shortly before man attained to his present rank in the zoological scale. Man, as I have attempted to shew, is

certainly descended from some apelike creature. With the existing Quadrumana, as far as their habits are

known, the males of some species are monogamous, but live during only a part of the year with the females:

of this the orang seems to afford an instance. Several kinds, for example some of the Indian and American

monkeys, are strictly monogamous, and associate all the year round with their wives. Others are polygamous,

for example the gorilla and several American species, and each family lives separate. Even when this occurs,

the families inhabiting the same district are probably somewhat social; the chimpanzee, for instance, is

occasionally met with in large bands. Again, other species are polygamous, but several males, each with his

own females, live associated in a body, as with several species of baboons. (9. Brehm ('Thierleben,' B. i. p.

77) says Cynocephalus hamadryas lives in great troops containing twice as many adult females as adult

males. See Rengger on American polygamous species, and Owen ('Anatomy of Vertebrates,' vol. iii. p. 746)

on American monogamous species. Other references might be added.) We may indeed conclude from what

we know of the jealousy of all male quadrupeds, armed, as many of them are, with special weapons for

battling with their rivals, that promiscuous intercourse in a state of nature is extremely improbable. The

pairing may not last for life, but only for each birth; yet if the males which are the strongest and best able to

defend or otherwise assist their females and young, were to select the more attractive females, this would

Therefore, looking far enough back in the stream of time, and judging from the social habits of man as he

now exists, the most probable view is that he aboriginally lived in small communities, each with a single

wife, or if powerful with several, whom he jealously guarded against all other men. Or he may not have been

a social animal, and yet have lived with several wives, like the gorilla; for all the natives "agree that but one

adult male is seen in a band; when the young male grows up, a contest takes place for mastery, and the

strongest, by killing and driving out the others, establishes himself as the head of the community." (10. Dr.

Savage, in 'Boston Journal of Natural History,' vol. v. 184547, p. 423.) The younger males, being thus

expelled and wandering about, would, when at last successful in finding a partner, prevent too close

Although savages are now extremely licentious, and although communal marriages may formerly have

largely prevailed, yet many tribes practise some form of marriage, but of a far more lax nature than that of

civilised nations. Polygamy, as just stated, is almost universally followed by the leading men in every tribe.

Nevertheless there are tribes, standing almost at the bottom of the scale, which are strictly monogamous. This

is the case with the Veddahs of Ceylon: they have a saying, according to Sir J. Lubbock (11. 'Prehistoric

Times,' 1869, p. 424.), "that death alone can separate husband and wife." An intelligent Kandyan chief, of

course a polygamist, "was perfectly scandalised at the utter barbarism of living with only one wife, and never

parting until separated by death." It was, he said, "just like the Wanderoo monkeys." Whether savages who

now enter into some form of marriage, either polygamous or monogamous, have retained this habit from

primeval times, or whether they have returned to some form of marriage, after passing through a stage of

This practice is now very common throughout the world, and there is reason to believe that it prevailed much

more extensively during former times. (12. Mr. M'Lennan, 'Primitive Marriage,' 1865. See especially on

exogamy and infanticide, pp. 130, 138, 165.) Barbarians find it difficult to support themselves and their

children, and it is a simple plan to kill their infants. In South America some tribes, according to Azara,

formerly destroyed so many infants of both sexes that they were on the point of extinction. In the Polynesian

Islands women have been known to kill from four or five, to even ten of their children; and Ellis could not

find a single woman who had not killed at least one. In a village on the eastern frontier of India Colonel

MacCulloch found not a single female child. Wherever infanticide (13. Dr. Gerland ('Ueber das Aussterben

der Naturvolker,' 1868) has collected much information on infanticide, see especially ss. 27, 51, 54. Azara

('Voyages,' etc., tom. ii. pp. 94, 116) enters in detail on the motives. See also M'Lennan (ibid. p. 139) for

cases in India. In the former reprints of the 2nd edition of this book an incorrect quotation from Sir G. Grey

was unfortunately given in the above passage and has now been removed from the text.) prevails the struggle

for existence will be in so far less severe, and all the members of the tribe will have an almost equally good

chance of rearing their few surviving children. In most cases a larger number of female than of male infants

are destroyed, for it is obvious that the latter are of more value to the tribe, as they will, when grown up, aid

in defending it, and can support themselves. But the trouble experienced by the women in rearing children,

their consequent loss of beauty, the higher estimation set on them when few, and their happier fate, are

assigned by the women themselves, and by various observers, as additional motives for infanticide.

When, owing to female infanticide, the women of a tribe were few, the habit of capturing wives from

neighbouring tribes would naturally arise. Sir J. Lubbock, however, as we have seen, attributes the practice in

chief part to the former existence of communal marriage, and to the men having consequently captured

women from other tribes to hold as their sole property. Additional causes might be assigned, such as the

communities being very small, in which case, marriageable women would often be deficient. That the habit

was most extensively practised during former times, even by the ancestors of civilised nations, is clearly

shewn by the preservation of many curious customs and ceremonies, of which Mr. M'Lennan has given an

interesting account. In our own marriages the "best man" seems originally to have been the chief abettor of

the bridegroom in the act of capture. Now as long as men habitually procured their wives through violence

and craft, they would have been glad to seize on any woman, and would not have selected the more attractive

ones. But as soon as the practice of procuring wives from a distinct tribe was effected through barter, as now

occurs in many places, the more attractive women would generally have been purchased. The incessant

crossing, however, between tribe and tribe, which necessarily follows from any form of this habit, would tend

to keep all the people inhabiting the same country nearly uniform in character; and this would interfere with

The scarcity of women, consequent on female infanticide, leads, also, to another practice, that of polyandry,

still common in several parts of the world, and which formerly, as Mr. M'Lennan believes, prevailed almost

universally: but this latter conclusion is doubted by Mr. Morgan and Sir J. Lubbock. (14. 'Primitive Marriage,'

p. 208; Sir J. Lubbock, 'Origin of Civilisation,' p. 100. See also Mr. Morgan, loc. cit., on the former

prevalence of polyandry.) Whenever two or more men are compelled to marry one woman, it is certain that

all the women of the tribe will get married, and there will be no selection by the men of the more attractive

women. But under these circumstances the women no doubt will have the power of choice, and will prefer

the more attractive men. Azara, for instance, describes how carefully a Guana woman bargains for all sorts of

privileges, before accepting some one or more husbands; and the men in consequence take unusual care of

their personal appearance. So amongst the Todas of India, who practise polyandry, the girls can accept or

refuse any man. (15. Azara, 'Voyages,' etc., tom. ii. pp. 9295; Colonel Marshall, 'Amongst the Todas,' p.

212.) A very ugly man in these cases would perhaps altogether fail in getting a wife, or get one later in life;

but the handsomer men, although more successful in obtaining wives, would not, as far as we can see, leave

more offspring to inherit their beauty than the less handsome husbands of the same women.

With many savages it is the custom to betroth the females whilst mere infants; and this would effectually

prevent preference being exerted on either side according to personal appearance. But it would not prevent

the more attractive women from being afterwards stolen or taken by force from their husbands by the more

powerful men; and this often happens in Australia, America, and elsewhere. The same consequences with

reference to sexual selection would to a certain extent follow, when women are valued almost solely as slaves

or beasts of burden, as is the case with many savages. The men, however, at all times would prefer the

We thus see that several customs prevail with savages which must greatly interfere with, or completely stop,

the action of sexual selection. On the other hand, the conditions of life to which savages are exposed, and

some of their habits, are favourable to natural selection; and this comes into play at the same time with sexual

selection. Savages are known to suffer severely from recurrent famines; they do not increase their food by

artificial means; they rarely refrain from marriage (16. Burchell says ('Travels in S. Africa,' vol. ii. 1824, p.

58), that among the wild nations of Southern Africa, neither men nor women ever pass their lives in a state of

celibacy. Azara ('Voyages dans l'Amerique Merid.' tom. ii. 1809, p. 21) makes precisely the same remark in

regard to the wild Indians of South America.), and generally marry whilst young. Consequently they must be

subjected to occasional hard struggles for existence, and the favoured individuals will alone survive.

At a very early period, before man attained to his present rank in the scale, many of his conditions would be

different from what now obtains amongst savages. Judging from the analogy of the lower animals, he would

then either live with a single female, or be a polygamist. The most powerful and able males would succeed

best in obtaining attractive females. They would also succeed best in the general struggle for life, and in

defending their females, as well as their offspring, from enemies of all kinds. At this early period the

ancestors of man would not be sufficiently advanced in intellect to look forward to distant contingencies; they

would not foresee that the rearing of all their children, especially their female children, would make the

struggle for life severer for the tribe. They would be governed more by their instincts and less by their reason

than are savages at the present day. They would not at that period have partially lost one of the strongest of

all instincts, common to all the lower animals, namely the love of their young offspring; and consequently

they would not have practised female infanticide. Women would not have been thus rendered scarce, and

polyandry would not have been practised; for hardly any other cause, except the scarcity of women seems

sufficient to break down the natural and widely prevalent feeling of jealousy, and the desire of each male to

possess a female for himself. Polyandry would be a natural steppingstone to communal marriages or almost

promiscuous intercourse; though the best authorities believe that this latter habit preceded polyandry. During

primordial times there would be no early betrothals, for this implies foresight. Nor would women be valued

merely as useful slaves or beasts of burthen. Both sexes, if the females as well as the males were permitted to

exert any choice, would choose their partners not for mental charms, or property, or social position, but

almost solely from external appearance. All the adults would marry or pair, and all the offspring, as far as that

was possible, would be reared; so that the struggle for existence would be periodically excessively severe.

Thus during these times all the conditions for sexual selection would have been more favourable than at a

later period, when man had advanced in his intellectual powers but had retrograded in his instincts. Therefore,

whatever influence sexual selection may have had in producing the differences between the races of man, and

between man and the higher Quadrumana, this influence would have been more powerful at a remote period

With primeval man under the favourable conditions just stated, and with those savages who at the present

time enter into any marriage tie, sexual selection has probably acted in the following manner, subject to

greater or less interference from female infanticide, early betrothals, etc. The strongest and most vigorous

menthose who could best defend and hunt for their families, who were provided with the best weapons and

possessed the most property, such as a large number of dogs or other animals,would succeed in rearing a

greater average number of offspring than the weaker and poorer members of the same tribes. There can, also,

be no doubt that such men would generally be able to select the more attractive women. At present the chiefs

of nearly every tribe throughout the world succeed in obtaining more than one wife. I hear from Mr. Mantell

that, until recently, almost every girl in New Zealand who was pretty, or promised to be pretty, was tapu to

some chief. With the Kafirs, as Mr. C. Hamilton states (17. 'Anthropological Review,' Jan. 1870, p. xvi.), "the

chiefs generally have the pick of the women for many miles round, and are most persevering in establishing

or confirming their privilege." We have seen that each race has its own style of beauty, and we know that it is

natural to man to admire each characteristic point in his domestic animals, dress, ornaments, and personal

appearance, when carried a little beyond the average. If then the several foregoing propositions be admitted,

and I cannot see that they are doubtful, it would be an inexplicable circumstance if the selection of the more

attractive women by the more powerful men of each tribe, who would rear on an average a greater number of

children, did not after the lapse of many generations somewhat modify the character of the tribe.

When a foreign breed of our domestic animals is introduced into a new country, or when a native breed is

long and carefully attended to, either for use or ornament, it is found after several generations to have

undergone a greater or less amount of change whenever the means of comparison exist. This follows from

unconscious selection during a long series of generationsthat is, the preservation of the most approved

individualswithout any wish or expectation of such a result on the part of the breeder. So again, if during

many years two careful breeders rear animals of the same family, and do not compare them together or with a

common standard, the animals are found to have become, to the surprise of their owners, slightly different.

(18. The 'Variation of Animals and Plants under Domestication,' vol. ii. pp. 210217.) Each breeder has

impressed, as von Nathusius well expresses it, the character of his own mindhis own taste and

judgmenton his animals. What reason, then, can be assigned why similar results should not follow from

the longcontinued selection of the most admired women by those men of each tribe who were able to rear

the greatest number of children? This would be unconscious selection, for an effect would be produced,

independently of any wish or expectation on the part of the men who preferred certain women to others.

Let us suppose the members of a tribe, practising some form of marriage, to spread over an unoccupied

continent, they would soon split up into distinct hordes, separated from each other by various barriers, and

still more effectually by the incessant wars between all barbarous nations. The hordes would thus be exposed

to slightly different conditions and habits of life, and would sooner or later come to differ in some small

degree. As soon as this occurred, each isolated tribe would form for itself a slightly different standard of

beauty (19. An ingenious writer argues, from a comparison of the pictures of Raphael, Rubens, and modern

French artists, that the idea of beauty is not absolutely the same even throughout Europe: see the 'Lives of

Haydn and Mozart,' by Bombet (otherwise M. Beyle), English translation, p. 278.); and then unconscious

selection would come into action through the more powerful and leading men preferring certain women to

others. Thus the differences between the tribes, at first very slight, would gradually and inevitably be more or

With animals in a state of nature, many characters proper to the males, such as size, strength, special

weapons, courage and pugnacity, have been acquired through the law of battle. The semihuman progenitors

of man, like their allies the Quadrumana, will almost certainly have been thus modified; and, as savages still

fight for the possession of their women, a similar process of selection has probably gone on in a greater or

less degree to the present day. Other characters proper to the males of the lower animals, such as bright

colours and various ornaments, have been acquired by the more attractive males having been preferred by the

females. There are, however, exceptional cases in which the males are the selectors, instead of having been

the selected. We recognise such cases by the females being more highly ornamented than the males,their

ornamental characters having been transmitted exclusively or chiefly to their female offspring. One such case

has been described in the order to which man belongs, that of the Rhesus monkey.

Man is more powerful in body and mind than woman, and in the savage state he keeps her in a far more

abject state of bondage than does the male of any other animal; therefore it is not surprising that he should

have gained the power of selection. Women are everywhere conscious of the value of their own beauty; and

when they have the means, they take more delight in decorating themselves with all sorts of ornaments than

do men. They borrow the plumes of male birds, with which nature has decked this sex, in order to charm the

females. As women have long been selected for beauty, it is not surprising that some of their successive

variations should have been transmitted exclusively to the same sex; consequently that they should have

transmitted beauty in a somewhat higher degree to their female than to their male offspring, and thus have

become more beautiful, according to general opinion, than men. Women, however, certainly transmit most of

their characters, including some beauty, to their offspring of both sexes; so that the continued preference by

the men of each race for the more attractive women, according to their standard of taste, will have tended to

modify in the same manner all the individuals of both sexes belonging to the race.

With respect to the other form of sexual selection (which with the lower animals is much the more common),

namely, when the females are the selectors, and accept only those males which excite or charm them most,

we have reason to believe that it formerly acted on our progenitors. Man in all probability owes his beard, and

perhaps some other characters, to inheritance from an ancient progenitor who thus gained his ornaments. But

this form of selection may have occasionally acted during later times; for in utterly barbarous tribes the

women have more power in choosing, rejecting, and tempting their lovers, or of afterwards changing their

husbands, than might have been expected. As this is a point of some importance, I will give in detail such

Hearne describes how a woman in one of the tribes of Arctic America repeatedly ran away from her husband

and joined her lover; and with the Charruas of S. America, according to Azara, divorce is quite optional.

Amongst the Abipones, a man on choosing a wife bargains with the parents about the price. But "it frequently

happens that the girl rescinds what has been agreed upon between the parents and the bridegroom, obstinately

rejecting the very mention of marriage." She often runs away, hides herself, and thus eludes the bridegroom.

Captain Musters who lived with the Patagonians, says that their marriages are always settled by inclination;

"if the parents make a match contrary to the daughter's will, she refuses and is never compelled to comply."

In Tierra del Fuego a young man first obtains the consent of the parents by doing them some service, and then

he attempts to carry off the girl; "but if she is unwilling, she hides herself in the woods until her admirer is

heartily tired of looking for her, and gives up the pursuit; but this seldom happens." In the Fiji Islands the

man seizes on the woman whom he wishes for his wife by actual or pretended force; but "on reaching the

home of her abductor, should she not approve of the match, she runs to some one who can protect her; if,

however, she is satisfied, the matter is settled forthwith." With the Kalmucks there is a regular race between

the bride and bridegroom, the former having a fair start; and Clarke "was assured that no instance occurs of a

girl being caught, unless she has a partiality to the pursuer." Amongst the wild tribes of the Malay

Archipelago there is also a racing match; and it appears from M. Bourien's account, as Sir J. Lubbock

remarks, that "the race, 'is not to the swift, nor the battle to the strong,' but to the young man who has the

good fortune to please his intended bride." A similar custom, with the same result, prevails with the Koraks

Turning to Africa: the Kafirs buy their wives, and girls are severely beaten by their fathers if they will not

accept a chosen husband; but it is manifest from many facts given by the Rev. Mr. Shooter, that they have

considerable power of choice. Thus very ugly, though rich men, have been known to fail in getting wives.

The girls, before consenting to be betrothed, compel the men to shew themselves off first in front and then

behind, and "exhibit their paces." They have been known to propose to a man, and they not rarely run away

with a favoured lover. So again, Mr. Leslie, who was intimately acquainted with the Kafirs, says, "it is a

mistake to imagine that a girl is sold by her father in the same manner, and with the same authority, with

which he would dispose of a cow." Amongst the degraded Bushmen of S. Africa, "when a girl has grown up

to womanhood without having been betrothed, which, however, does not often happen, her lover must gain

her approbation, as well as that of the parents." (20. Azara, 'Voyages,' etc., tom. ii. p. 23. Dobrizhoffer, 'An

Account of the Abipones,' vol. ii. 1822, p. 207. Capt. Musters, in 'Proc. R. Geograph. Soc.' vol. xv. p. 47.

Williams on the Fiji Islanders, as quoted by Lubbock, 'Origin of Civilisation,' 1870, p. 79. On the Fuegians,

King and Fitzroy, 'Voyages of the "Adventure" and "Beagle,"' vol. ii. 1839, p. 182. On the Kalmucks, quoted

by M'Lennan, 'Primitive Marriage,' 1865, p. 32. On the Malays, Lubbock, ibid. p. 76. The Rev. J. Shooter,

'On the Kafirs of Natal,' 1857, pp. 5260. Mr. D. Leslie, 'Kafir Character and Customs,' 1871, p. 4. On the

Bushmen, Burchell, 'Travels in S. Africa,' ii. 1824, p. 59. On the Koraks by McKennan, as quoted by Mr.

Wake, in 'Anthropologia,' Oct. 1873, p. 75.) Mr. Winwood Reade made inquiries for me with respect to the

negroes of Western Africa, and he informs me that "the women, at least among the more intelligent Pagan

tribes, have no difficulty in getting the husbands whom they may desire, although it is considered unwomanly

to ask a man to marry them. They are quite capable of falling in love, and of forming tender, passionate, and

We thus see that with savages the women are not in quite so abject a state in relation to marriage as has often

been supposed. They can tempt the men whom they prefer, and can sometimes reject those whom they

dislike, either before or after marriage. Preference on the part of the women, steadily acting in any one

direction, would ultimately affect the character of the tribe; for the women would generally choose not

merely the handsomest men, according to their standard of taste, but those who were at the same time best

able to defend and support them. Such wellendowed pairs would commonly rear a larger number of

offspring than the less favoured. The same result would obviously follow in a still more marked manner if

there was selection on both sides; that is, if the more attractive, and at the same time more powerful men were

to prefer, and were preferred by, the more attractive women. And this double form of selection seems actually

We will now examine a little more closely some of the characters which distinguish the several races of man

from one another and from the lower animals, namely, the greater or less deficiency of hair on the body, and

the colour of the skin. We need say nothing about the great diversity in the shape of the features and of the

skull between the different races, as we have seen in the last chapter how different is the standard of beauty in

these respects. These characters will therefore probably have been acted on through sexual selection; but we

have no means of judging whether they have been acted on chiefly from the male or female side. The musical

From the presence of the woolly hair or lanugo on the human foetus, and of rudimentary hairs scattered over

the body during maturity, we may infer that man is descended from some animal which was born hairy and

remained so during life. The loss of hair is an inconvenience and probably an injury to man, even in a hot

climate, for he is thus exposed to the scorching of the sun, and to sudden chills, especially during wet

weather. As Mr. Wallace remarks, the natives in all countries are glad to protect their naked backs and

shoulders with some slight covering. No one supposes that the nakedness of the skin is any direct advantage

to man; his body therefore cannot have been divested of hair through natural selection. (21. 'Contributions to

the Theory of Natural Selection,' 1870, p. 346. Mr. Wallace believes (p. 350) "that some intelligent power has

guided or determined the development of man"; and he considers the hairless condition of the skin as coming

under this head. The Rev. T.R. Stebbing, in commenting on this view ('Transactions of Devonshire

Association for Science,' 1870) remarks, that had Mr. Wallace "employed his usual ingenuity on the question

of man's hairless skin, he might have seen the possibility of its selection through its superior beauty or the

health attaching to superior cleanliness.") Nor, as shewn in a former chapter, have we any evidence that this

can be due to the direct action of climate, or that it is the result of correlated development.

The absence of hair on the body is to a certain extent a secondary sexual character; for in all parts of the

world women are less hairy than men. Therefore we may reasonably suspect that this character has been

gained through sexual selection. We know that the faces of several species of monkeys, and large surfaces at

the posterior end of the body of other species, have been denuded of hair; and this we may safely attribute to

sexual selection, for these surfaces are not only vividly coloured, but sometimes, as with the male mandrill

and female rhesus, much more vividly in the one sex than in the other, especially during the breedingseason.

I am informed by Mr. Bartlett that, as these animals gradually reach maturity, the naked surfaces grow larger

compared with the size of their bodies. The hair, however, appears to have been removed, not for the sake of

nudity, but that the colour of the skin may be more fully displayed. So again with many birds, it appears as if

the head and neck had been divested of feathers through sexual selection, to exhibit the brightlycoloured

As the body in woman is less hairy than in man, and as this character is common to all races, we may

conclude that it was our female semihuman ancestors who were first divested of hair, and that this occurred

at an extremely remote period before the several races had diverged from a common stock. Whilst our female

ancestors were gradually acquiring this new character of nudity, they must have transmitted it almost equally

to their offspring of both sexes whilst young; so that its transmission, as with the ornaments of many

mammals and birds, has not been limited either by sex or age. There is nothing surprising in a partial loss of

hair having been esteemed as an ornament by our apelike progenitors, for we have seen that innumerable

strange characters have been thus esteemed by animals of all kinds, and have consequently been gained

through sexual selection. Nor is it surprising that a slightly injurious character should have been thus

acquired; for we know that this is the case with the plumes of certain birds, and with the horns of certain

The females of some of the anthropoid apes, as stated in a former chapter, are somewhat less hairy on the

under surface than the males; and here we have what might have afforded a commencement for the process of

denudation. With respect to the completion of the process through sexual selection, it is well to bear in mind

the New Zealand proverb, "There is no woman for a hairy man." All who have seen photographs of the

Siamese hairy family will admit how ludicrously hideous is the opposite extreme of excessive hairiness. And

the king of Siam had to bribe a man to marry the first hairy woman in the family; and she transmitted this

character to her young offspring of both sexes. (22. The 'Variation of Animals and Plants under

Some races are much more hairy than others, especially the males; but it must not be assumed that the more

hairy races, such as the European, have retained their primordial condition more completely than the naked

races, such as the Kalmucks or Americans. It is more probable that the hairiness of the former is due to partial

reversion; for characters which have been at some former period long inherited are always apt to return. We

have seen that idiots are often very hairy, and they are apt to revert in other characters to a lower animal type.

It does not appear that a cold climate has been influential in leading to this kind of reversion; excepting

perhaps with the negroes, who have been reared during several generations in the United States (23.

'Investigations into Military and Anthropological Statistics of American Soldiers,' by B.A. Gould, 1869, p.

568:Observations were carefully made on the hairiness of 2129 black and coloured soldiers, whilst they

were bathing; and by looking to the published table, "it is manifest at a glance that there is but little, if any,

difference between the white and the black races in this respect." It is, however, certain that negroes in their

native and much hotter land of Africa, have remarkably smooth bodies. It should be particularly observed,

that both pure blacks and mulattoes were included in the above enumeration; and this is an unfortunate

circumstance, as in accordance with a principle, the truth of which I have elsewhere proved, crossed races of

man would be eminently liable to revert to the primordial hairy character of their early apelike progenitors.),

and possibly with the Ainos, who inhabit the northern islands of the Japan archipelago. But the laws of

inheritance are so complex that we can seldom understand their action. If the greater hairiness of certain races

be the result of reversion, unchecked by any form of selection, its extreme variability, even within the limits

of the same race, ceases to be remarkable. (24. Hardly any view advanced in this work has met with so much

disfavour (see for instance, Sprengel, 'Die Fortschritte des Darwinismus,' 1874, p. 80) as the above

explanation of the loss of hair in mankind through sexual selection; but none of the opposed arguments seem

to me of much weight, in comparison with the facts shewing that the nudity of the skin is to a certain extent a

With respect to the beard in man, if we turn to our best guide, the Quadrumana, we find beards equally

developed in both sexes of many species, but in some, either confined to the males, or more developed in

them than in the females. From this fact and from the curious arrangement, as well as the bright colours of the

hair about the heads of many monkeys, it is highly probable, as before explained, that the males first acquired

their beards through sexual selection as an ornament, transmitting them in most cases, equally or nearly so, to

their offspring of both sexes. We know from Eschricht (25. 'Ueber die Richtung der Haare am Menschlichen

Korper,' in Muller's 'Archiv. fur Anat. und Phys.' 1837, s. 40.) that with mankind the female as well as the

male foetus is furnished with much hair on the face, especially round the mouth; and this indicates that we are

descended from progenitors of whom both sexes were bearded. It appears therefore at first sight probable that

man has retained his beard from a very early period, whilst woman lost her beard at the same time that her

body became almost completely divested of hair. Even the colour of our beards seems to have been inherited

from an apelike progenitor; for when there is any difference in tint between the hair of the head and the

beard, the latter is lighter coloured in all monkeys and in man. In those Quadrumana in which the male has a

larger beard than that of the female, it is fully developed only at maturity, just as with mankind; and it is

possible that only the later stages of development have been retained by man. In opposition to this view of the

retention of the beard from an early period is the fact of its great variability in different races, and even within

the same race; for this indicates reversion,long lost characters being very apt to vary on reappearance.

Nor must we overlook the part which sexual selection may have played in later times; for we know that with

savages the men of the beardless races take infinite pains in eradicating every hair from their faces as

something odious, whilst the men of the bearded races feel the greatest pride in their beards. The women, no

doubt, participate in these feelings, and if so sexual selection can hardly have failed to have effected

something in the course of later times. It is also possible that the longcontinued habit of eradicating the hair

may have produced an inherited effect. Dr. BrownSequard has shewn that if certain animals are operated on

in a particular manner, their offspring are affected. Further evidence could be given of the inheritance of the

effects of mutilations; but a fact lately ascertained by Mr. Salvin (26. On the tailfeathers of Motmots,

'Proceedings of the Zoological Society,' 1873, p. 429.) has a more direct bearing on the present question; for

he has shewn that the motmots, which are known habitually to bite off the barbs of the two central tail

feathers, have the barbs of these feathers naturally somewhat reduced. (27. Mr. Sproat has suggested ('Scenes

and Studies of Savage Life,' 1868, p. 25) this same view. Some distinguished ethnologists, amongst others M.

Gosse of Geneva, believe that artificial modifications of the skull tend to be inherited.) Nevertheless, with

mankind the habit of eradicating the beard and the hairs on the body would probably not have arisen until

It is difficult to form any judgment as to how the hair on the head became developed to its present great

length in many races. Eschricht (28. 'Ueber die Richtung,' ibid. s. 40.) states that in the human foetus the hair

on the face during the fifth month is longer than that on the head; and this indicates that our semihuman

progenitors were not furnished with long tresses, which must therefore have been a late acquisition. This is

likewise indicated by the extraordinary difference in the length of the hair in the different races; in the negro

the hair forms a mere curly mat; with us it is of great length, and with the American natives it not rarely

reaches to the ground. Some species of Semnopithecus have their heads covered with moderately long hair,

and this probably serves as an ornament and was acquired through sexual selection. The same view may

perhaps be extended to mankind, for we know that long tresses are now and were formerly much admired, as

may be observed in the works of almost every poet; St. Paul says, "if a woman have long hair, it is a glory to

her;" and we have seen that in North America a chief was elected solely from the length of his hair.

The best kind of evidence that in man the colour of the skin has been modified through sexual selection is

scanty; for in most races the sexes do not differ in this respect, and only slightly, as we have seen, in others.

We know, however, from the many facts already given that the colour of the skin is regarded by the men of

all races as a highly important element in their beauty; so that it is a character which would be likely to have

been modified through selection, as has occurred in innumerable instances with the lower animals. It seems at

first sight a monstrous supposition that the jetblackness of the negro should have been gained through

sexual selection; but this view is supported by various analogies, and we know that negroes admire their own

colour. With mammals, when the sexes differ in colour, the male is often black or much darker than the

female; and it depends merely on the form of inheritance whether this or any other tint is transmitted to both

sexes or to one alone. The resemblance to a negro in miniature of Pithecia satanas with his jet black skin,

white rolling eyeballs, and hair parted on the top of the head, is almost ludicrous.

The colour of the face differs much more widely in the various kinds of monkeys than it does in the races of

man; and we have some reason to believe that the red, blue, orange, almost white and black tints of their skin,

even when common to both sexes, as well as the bright colours of their fur, and the ornamental tufts about the

head, have all been acquired through sexual selection. As the order of development during growth, generally

indicates the order in which the characters of a species have been developed and modified during previous

generations; and as the newly born infants of the various races of man do not differ nearly as much in colour

as do the adults, although their bodies are as completely destitute of hair, we have some slight evidence that

the tints of the different races were acquired at a period subsequent to the removal of the hair, which must

We may conclude that the greater size, strength, courage, pugnacity, and energy of man, in comparison with

woman, were acquired during primeval times, and have subsequently been augmented, chiefly through the

contests of rival males for the possession of the females. The greater intellectual vigour and power of

invention in man is probably due to natural selection, combined with the inherited effects of habit, for the

most able men will have succeeded best in defending and providing for themselves and for their wives and

offspring. As far as the extreme intricacy of the subject permits us to judge, it appears that our male apelike

progenitors acquired their beards as an ornament to charm or excite the opposite sex, and transmitted them

only to their male offspring. The females apparently first had their bodies denuded of hair, also as a sexual

ornament; but they transmitted this character almost equally to both sexes. It is not improbable that the

females were modified in other respects for the same purpose and by the same means; so that women have

It deserves attention that with mankind the conditions were in many respects much more favourable for

sexual selection, during a very early period, when man had only just attained to the rank of manhood, than

during later times. For he would then, as we may safely conclude, have been guided more by his instinctive

passions, and less by foresight or reason. He would have jealously guarded his wife or wives. He would not

have practised infanticide; nor valued his wives merely as useful slaves; nor have been betrothed to them

during infancy. Hence we may infer that the races of men were differentiated, as far as sexual selection is

concerned, in chief part at a very remote epoch; and this conclusion throws light on the remarkable fact that

at the most ancient period, of which we have not as yet any record, the races of man had already come to

The views here advanced, on the part which sexual selection has played in the history of man, want scientific

precision. He who does not admit this agency in the case of the lower animals, will disregard all that I have

written in the later chapters on man. We cannot positively say that this character, but not that, has been thus

modified; it has, however, been shewn that the races of man differ from each other and from their nearest

allies, in certain characters which are of no service to them in their daily habits of life, and which it is

extremely probable would have been modified through sexual selection. We have seen that with the lowest

savages the people of each tribe admire their own characteristic qualities,the shape of the head and face,

the squareness of the cheek bones, the prominence or depression of the nose, the colour of the skin, the

length of the hair on the head, the absence of hair on the face and body, or the presence of a great beard, and

so forth. Hence these and other such points could hardly fail to be slowly and gradually exaggerated, from the

more powerful and able men in each tribe, who would succeed in rearing the largest number of offspring,

having selected during many generations for their wives the most strongly characterised and therefore most

attractive women. For my own part I conclude that of all the causes which have led to the differences in

external appearance between the races of man, and to a certain extent between man and the lower animals,

Main conclusion that man is descended from some lower formManner of developmentGenealogy of

A brief summary will be sufficient to recall to the reader's mind the more salient points in this work. Many of

the views which have been advanced are highly speculative, and some no doubt will prove erroneous; but I

have in every case given the reasons which have led me to one view rather than to another. It seemed worth

while to try how far the principle of evolution would throw light on some of the more complex problems in

the natural history of man. False facts are highly injurious to the progress of science, for they often endure

long; but false views, if supported by some evidence, do little harm, for every one takes a salutary pleasure in

proving their falseness: and when this is done, one path towards error is closed and the road to truth is often

The main conclusion here arrived at, and now held by many naturalists who are well competent to form a

sound judgment, is that man is descended from some less highly organised form. The grounds upon which

this conclusion rests will never be shaken, for the close similarity between man and the lower animals in

embryonic development, as well as in innumerable points of structure and constitution, both of high and of

the most trifling importance,the rudiments which he retains, and the abnormal reversions to which he is

occasionally liable,are facts which cannot be disputed. They have long been known, but until recently they

told us nothing with respect to the origin of man. Now when viewed by the light of our knowledge of the

whole organic world, their meaning is unmistakable. The great principle of evolution stands up clear and

firm, when these groups or facts are considered in connection with others, such as the mutual affinities of the

members of the same group, their geographical distribution in past and present times, and their geological

succession. It is incredible that all these facts should speak falsely. He who is not content to look, like a

savage, at the phenomena of nature as disconnected, cannot any longer believe that man is the work of a

separate act of creation. He will be forced to admit that the close resemblance of the embryo of man to that,

for instance, of a dogthe construction of his skull, limbs and whole frame on the same plan with that of

other mammals, independently of the uses to which the parts may be putthe occasional reappearance of

various structures, for instance of several muscles, which man does not normally possess, but which are

common to the Quadrumanaand a crowd of analogous factsall point in the plainest manner to the

conclusion that man is the codescendant with other mammals of a common progenitor.

We have seen that man incessantly presents individual differences in all parts of his body and in his mental

faculties. These differences or variations seem to be induced by the same general causes, and to obey the

same laws as with the lower animals. In both cases similar laws of inheritance prevail. Man tends to increase

at a greater rate than his means of subsistence; consequently he is occasionally subjected to a severe struggle

for existence, and natural selection will have effected whatever lies within its scope. A succession of

stronglymarked variations of a similar nature is by no means requisite; slight fluctuating differences in the

individual suffice for the work of natural selection; not that we have any reason to suppose that in the same

species, all parts of the organisation tend to vary to the same degree. We may feel assured that the inherited

effects of the longcontinued use or disuse of parts will have done much in the same direction with natural

selection. Modifications formerly of importance, though no longer of any special use, are long inherited.

When one part is modified, other parts change through the principle of correlation, of which we have

instances in many curious cases of correlated monstrosities. Something may be attributed to the direct and

definite action of the surrounding conditions of life, such as abundant food, heat or moisture; and lastly, many

characters of slight physiological importance, some indeed of considerable importance, have been gained

No doubt man, as well as every other animal, presents structures, which seem to our limited knowledge, not

to be now of any service to him, nor to have been so formerly, either for the general conditions of life, or in

the relations of one sex to the other. Such structures cannot be accounted for by any form of selection, or by

the inherited effects of the use and disuse of parts. We know, however, that many strange and

stronglymarked peculiarities of structure occasionally appear in our domesticated productions, and if their

unknown causes were to act more uniformly, they would probably become common to all the individuals of

the species. We may hope hereafter to understand something about the causes of such occasional

modifications, especially through the study of monstrosities: hence the labours of experimentalists, such as

those of M. Camille Dareste, are full of promise for the future. In general we can only say that the cause of

each slight variation and of each monstrosity lies much more in the constitution of the organism, than in the

nature of the surrounding conditions; though new and changed conditions certainly play an important part in

Through the means just specified, aided perhaps by others as yet undiscovered, man has been raised to his

present state. But since he attained to the rank of manhood, he has diverged into distinct races, or as they may

be more fitly called, subspecies. Some of these, such as the Negro and European, are so distinct that, if

specimens had been brought to a naturalist without any further information, they would undoubtedly have

been considered by him as good and true species. Nevertheless all the races agree in so many unimportant

details of structure and in so many mental peculiarities that these can be accounted for only by inheritance

from a common progenitor; and a progenitor thus characterised would probably deserve to rank as man.

It must not be supposed that the divergence of each race from the other races, and of all from a common

stock, can be traced back to any one pair of progenitors. On the contrary, at every stage in the process of

modification, all the individuals which were in any way better fitted for their conditions of life, though in

different degrees, would have survived in greater numbers than the less wellfitted. The process would have

been like that followed by man, when he does not intentionally select particular individuals, but breeds from

all the superior individuals, and neglects the inferior. He thus slowly but surely modifies his stock, and

unconsciously forms a new strain. So with respect to modifications acquired independently of selection, and

due to variations arising from the nature of the organism and the action of the surrounding conditions, or from

changed habits of life, no single pair will have been modified much more than the other pairs inhabiting the

same country, for all will have been continually blended through free intercrossing.

By considering the embryological structure of man,the homologies which he presents with the lower

animals,the rudiments which he retains,and the reversions to which he is liable, we can partly recall in

imagination the former condition of our early progenitors; and can approximately place them in their proper

place in the zoological series. We thus learn that man is descended from a hairy, tailed quadruped, probably

arboreal in its habits, and an inhabitant of the Old World. This creature, if its whole structure had been

examined by a naturalist, would have been classed amongst the Quadrumana, as surely as the still more

ancient progenitor of the Old and New World monkeys. The Quadrumana and all the higher mammals are

probably derived from an ancient marsupial animal, and this through a long line of diversified forms, from

some amphibianlike creature, and this again from some fishlike animal. In the dim obscurity of the past we

can see that the early progenitor of all the Vertebrata must have been an aquatic animal, provided with

branchiae, with the two sexes united in the same individual, and with the most important organs of the body

(such as the brain and heart) imperfectly or not at all developed. This animal seems to have been more like

The high standard of our intellectual powers and moral disposition is the greatest difficulty which presents

itself, after we have been driven to this conclusion on the origin of man. But every one who admits the

principle of evolution, must see that the mental powers of the higher animals, which are the same in kind with

those of man, though so different in degree, are capable of advancement. Thus the interval between the

mental powers of one of the higher apes and of a fish, or between those of an ant and scaleinsect, is

immense; yet their development does not offer any special difficulty; for with our domesticated animals, the

mental faculties are certainly variable, and the variations are inherited. No one doubts that they are of the

utmost importance to animals in a state of nature. Therefore the conditions are favourable for their

development through natural selection. The same conclusion may be extended to man; the intellect must have

been allimportant to him, even at a very remote period, as enabling him to invent and use language, to make

weapons, tools, traps, etc., whereby with the aid of his social habits, he long ago became the most dominant

A great stride in the development of the intellect will have followed, as soon as the halfart and halfinstinct

of language came into use; for the continued use of language will have reacted on the brain and produced an

inherited effect; and this again will have reacted on the improvement of language. As Mr. Chauncey Wright

(1. 'On the Limits of Natural Selection,' in the 'North American Review,' Oct. 1870, p. 295.) has well

remarked, the largeness of the brain in man relatively to his body, compared with the lower animals, may be

attributed in chief part to the early use of some simple form of language,that wonderful engine which

affixes signs to all sorts of objects and qualities, and excites trains of thought which would never arise from

the mere impression of the senses, or if they did arise could not be followed out. The higher intellectual

powers of man, such as those of ratiocination, abstraction, self consciousness, etc., probably follow from the

The development of the moral qualities is a more interesting problem. The foundation lies in the social

instincts, including under this term the family ties. These instincts are highly complex, and in the case of the

lower animals give special tendencies towards certain definite actions; but the more important elements are

love, and the distinct emotion of sympathy. Animals endowed with the social instincts take pleasure in one

another's company, warn one another of danger, defend and aid one another in many ways. These instincts do

not extend to all the individuals of the species, but only to those of the same community. As they are highly

beneficial to the species, they have in all probability been acquired through natural selection.

A moral being is one who is capable of reflecting on his past actions and their motivesof approving of

some and disapproving of others; and the fact that man is the one being who certainly deserves this

designation, is the greatest of all distinctions between him and the lower animals. But in the fourth chapter I

have endeavoured to shew that the moral sense follows, firstly, from the enduring and everpresent nature of

the social instincts; secondly, from man's appreciation of the approbation and disapprobation of his fellows;

and thirdly, from the high activity of his mental faculties, with past impressions extremely vivid; and in these

latter respects he differs from the lower animals. Owing to this condition of mind, man cannot avoid looking

both backwards and forwards, and comparing past impressions. Hence after some temporary desire or passion

has mastered his social instincts, he reflects and compares the now weakened impression of such past

impulses with the everpresent social instincts; and he then feels that sense of dissatisfaction which all

unsatisfied instincts leave behind them, he therefore resolves to act differently for the future,and this is

conscience. Any instinct, permanently stronger or more enduring than another, gives rise to a feeling which

we express by saying that it ought to be obeyed. A pointer dog, if able to reflect on his past conduct, would

say to himself, I ought (as indeed we say of him) to have pointed at that hare and not have yielded to the

Social animals are impelled partly by a wish to aid the members of their community in a general manner, but

more commonly to perform certain definite actions. Man is impelled by the same general wish to aid his

fellows; but has few or no special instincts. He differs also from the lower animals in the power of expressing

his desires by words, which thus become a guide to the aid required and bestowed. The motive to give aid is

likewise much modified in man: it no longer consists solely of a blind instinctive impulse, but is much

influenced by the praise or blame of his fellows. The appreciation and the bestowal of praise and blame both

rest on sympathy; and this emotion, as we have seen, is one of the most important elements of the social

instincts. Sympathy, though gained as an instinct, is also much strengthened by exercise or habit. As all men

desire their own happiness, praise or blame is bestowed on actions and motives, according as they lead to this

end; and as happiness is an essential part of the general good, the greatesthappinesss principle indirectly

serves as a nearly safe standard of right and wrong. As the reasoning powers advance and experience is

gained, the remoter effects of certain lines of conduct on the character of the individual, and on the general

good, are perceived; and then the selfregarding virtues come within the scope of public opinion, and receive

praise, and their opposites blame. But with the less civilised nations reason often errs, and many bad customs

and base superstitions come within the same scope, and are then esteemed as high virtues, and their breach as

The moral faculties are generally and justly esteemed as of higher value than the intellectual powers. But we

should bear in mind that the activity of the mind in vividly recalling past impressions is one of the

fundamental though secondary bases of conscience. This affords the strongest argument for educating and

stimulating in all possible ways the intellectual faculties of every human being. No doubt a man with a torpid

mind, if his social affections and sympathies are well developed, will be led to good actions, and may have a

fairly sensitive conscience. But whatever renders the imagination more vivid and strengthens the habit of

recalling and comparing past impressions, will make the conscience more sensitive, and may even somewhat

The moral nature of man has reached its present standard, partly through the advancement of his reasoning

powers and consequently of a just public opinion, but especially from his sympathies having been rendered

more tender and widely diffused through the effects of habit, example, instruction, and reflection. It is not

improbable that after long practice virtuous tendencies may be inherited. With the more civilised races, the

conviction of the existence of an allseeing Deity has had a potent influence on the advance of morality.

Ultimately man does not accept the praise or blame of his fellows as his sole guide, though few escape this

influence, but his habitual convictions, controlled by reason, afford him the safest rule. His conscience then

becomes the supreme judge and monitor. Nevertheless the first foundation or origin of the moral sense lies in

the social instincts, including sympathy; and these instincts no doubt were primarily gained, as in the case of

The belief in God has often been advanced as not only the greatest, but the most complete of all the

distinctions between man and the lower animals. It is however impossible, as we have seen, to maintain that

this belief is innate or instinctive in man. On the other hand a belief in allpervading spiritual agencies seems

to be universal; and apparently follows from a considerable advance in man's reason, and from a still greater

advance in his faculties of imagination, curiosity and wonder. I am aware that the assumed instinctive belief

in God has been used by many persons as an argument for His existence. But this is a rash argument, as we

should thus be compelled to believe in the existence of many cruel and malignant spirits, only a little more

powerful than man; for the belief in them is far more general than in a beneficent Deity. The idea of a

universal and beneficent Creator does not seem to arise in the mind of man, until he has been elevated by

He who believes in the advancement of man from some low organised form, will naturally ask how does this

bear on the belief in the immortality of the soul. The barbarous races of man, as Sir J. Lubbock has shewn,

possess no clear belief of this kind; but arguments derived from the primeval beliefs of savages are, as we

have just seen, of little or no avail. Few persons feel any anxiety from the impossibility of determining at

what precise period in the development of the individual, from the first trace of a minute germinal vesicle,

man becomes an immortal being; and there is no greater cause for anxiety because the period cannot possibly

be determined in the gradually ascending organic scale. (2. The Rev. J.A. Picton gives a discussion to this

I am aware that the conclusions arrived at in this work will be denounced by some as highly irreligious; but

he who denounces them is bound to shew why it is more irreligious to explain the origin of man as a distinct

species by descent from some lower form, through the laws of variation and natural selection, than to explain

the birth of the individual through the laws of ordinary reproduction. The birth both of the species and of the

individual are equally parts of that grand sequence of events, which our minds refuse to accept as the result of

blind chance. The understanding revolts at such a conclusion, whether or not we are able to believe that every

slight variation of structure,the union of each pair in marriage, the dissemination of each seed,and other

Sexual selection has been treated at great length in this work; for, as I have attempted to shew, it has played

an important part in the history of the organic world. I am aware that much remains doubtful, but I have

endeavoured to give a fair view of the whole case. In the lower divisions of the animal kingdom, sexual

selection seems to have done nothing: such animals are often affixed for life to the same spot, or have the

sexes combined in the same individual, or what is still more important, their perceptive and intellectual

faculties are not sufficiently advanced to allow of the feelings of love and jealousy, or of the exertion of

choice. When, however, we come to the Arthropoda and Vertebrata, even to the lowest classes in these two

In the several great classes of the animal kingdom,in mammals, birds, reptiles, fishes, insects, and even

crustaceans,the differences between the sexes follow nearly the same rules. The males are almost always

the wooers; and they alone are armed with special weapons for fighting with their rivals. They are generally

stronger and larger than the females, and are endowed with the requisite qualities of courage and pugnacity.

They are provided, either exclusively or in a much higher degree than the females, with organs for vocal or

instrumental music, and with odoriferous glands. They are ornamented with infinitely diversified appendages,

and with the most brilliant or conspicuous colours, often arranged in elegant patterns, whilst the females are

unadorned. When the sexes differ in more important structures, it is the male which is provided with special

sense organs for discovering the female, with locomotive organs for reaching her, and often with prehensile

organs for holding her. These various structures for charming or securing the female are often developed in

the male during only part of the year, namely the breedingseason. They have in many cases been more or

less transferred to the females; and in the latter case they often appear in her as mere rudiments. They are lost

or never gained by the males after emasculation. Generally they are not developed in the male during early

youth, but appear a short time before the age for reproduction. Hence in most cases the young of both sexes

resemble each other; and the female somewhat resembles her young offspring throughout life. In almost

every great class a few anomalous cases occur, where there has been an almost complete transposition of the

characters proper to the two sexes; the females assuming characters which properly belong to the males. This

surprising uniformity in the laws regulating the differences between the sexes in so many and such widely

separated classes, is intelligible if we admit the action of one common cause, namely sexual selection.

Sexual selection depends on the success of certain individuals over others of the same sex, in relation to the

propagation of the species; whilst natural selection depends on the success of both sexes, at all ages, in

relation to the general conditions of life. The sexual struggle is of two kinds; in the one it is between

individuals of the same sex, generally the males, in order to drive away or kill their rivals, the females

remaining passive; whilst in the other, the struggle is likewise between the individuals of the same sex, in

order to excite or charm those of the opposite sex, generally the females, which no longer remain passive, but

select the more agreeable partners. This latter kind of selection is closely analogous to that which man

unintentionally, yet effectually, brings to bear on his domesticated productions, when he preserves during a

long period the most pleasing or useful individuals, without any wish to modify the breed.

The laws of inheritance determine whether characters gained through sexual selection by either sex shall be

transmitted to the same sex, or to both; as well as the age at which they shall be developed. It appears that

variations arising late in life are commonly transmitted to one and the same sex. Variability is the necessary

basis for the action of selection, and is wholly independent of it. It follows from this, that variations of the

same general nature have often been taken advantage of and accumulated through sexual selection in relation

to the propagation of the species, as well as through natural selection in relation to the general purposes of

life. Hence secondary sexual characters, when equally transmitted to both sexes can be distinguished from

ordinary specific characters only by the light of analogy. The modifications acquired through sexual selection

are often so strongly pronounced that the two sexes have frequently been ranked as distinct species, or even

as distinct genera. Such stronglymarked differences must be in some manner highly important; and we

know that they have been acquired in some instances at the cost not only of inconvenience, but of exposure to

The belief in the power of sexual selection rests chiefly on the following considerations. Certain characters

are confined to one sex; and this alone renders it probable that in most cases they are connected with the act

of reproduction. In innumerable instances these characters are fully developed only at maturity, and often

during only a part of the year, which is always the breedingseason. The males (passing over a few

exceptional cases) are the more active in courtship; they are the better armed, and are rendered the more

attractive in various ways. It is to be especially observed that the males display their attractions with elaborate

care in the presence of the females; and that they rarely or never display them excepting during the season of

love. It is incredible that all this should be purposeless. Lastly we have distinct evidence with some

quadrupeds and birds, that the individuals of one sex are capable of feeling a strong antipathy or preference

Bearing in mind these facts, and the marked results of man's unconscious selection, when applied to

domesticated animals and cultivated plants, it seems to me almost certain that if the individuals of one sex

were during a long series of generations to prefer pairing with certain individuals of the other sex,

characterised in some peculiar manner, the offspring would slowly but surely become modified in this same

manner. I have not attempted to conceal that, excepting when the males are more numerous than the females,

or when polygamy prevails, it is doubtful how the more attractive males succeed in leaving a large number of

offspring to inherit their superiority in ornaments or other charms than the less attractive males; but I have

shewn that this would probably follow from the females, especially the more vigorous ones, which would

be the first to breed, preferring not only the more attractive but at the same time the more vigorous and

Although we have some positive evidence that birds appreciate bright and beautiful objects, as with the

bowerbirds of Australia, and although they certainly appreciate the power of song, yet I fully admit that it is

astonishing that the females of many birds and some mammals should be endowed with sufficient taste to

appreciate ornaments, which we have reason to attribute to sexual selection; and this is even more astonishing

in the case of reptiles, fish, and insects. But we really know little about the minds of the lower animals. It

cannot be supposed, for instance, that male birds of paradise or peacocks should take such pains in erecting,

spreading, and vibrating their beautiful plumes before the females for no purpose. We should remember the

fact given on excellent authority in a former chapter, that several peahens, when debarred from an admired

Nevertheless I know of no fact in natural history more wonderful than that the female Argus pheasant should

appreciate the exquisite shading of the ballandsocket ornaments and the elegant patterns on the

wingfeather of the male. He who thinks that the male was created as he now exists must admit that the great

plumes, which prevent the wings from being used for flight, and which are displayed during courtship and at

no other time in a manner quite peculiar to this one species, were given to him as an ornament. If so, he must

likewise admit that the female was created and endowed with the capacity of appreciating such ornaments. I

differ only in the conviction that the male Argus pheasant acquired his beauty gradually, through the

preference of the females during many generations for the more highly ornamented males; the aesthetic

capacity of the females having been advanced through exercise or habit, just as our own taste is gradually

improved. In the male through the fortunate chance of a few feathers being left unchanged, we can distinctly

trace how simple spots with a little fulvous shading on one side may have been developed by small steps into

the wonderful ballandsocket ornaments; and it is probable that they were actually thus developed.

Everyone who admits the principle of evolution, and yet feels great difficulty in admitting that female

mammals, birds, reptiles, and fish, could have acquired the high taste implied by the beauty of the males, and

which generally coincides with our own standard, should reflect that the nervecells of the brain in the

highest as well as in the lowest members of the Vertebrate series, are derived from those of the common

progenitor of this great Kingdom. For we can thus see how it has come to pass that certain mental faculties, in

various and widely distinct groups of animals, have been developed in nearly the same manner and to nearly

The reader who has taken the trouble to go through the several chapters devoted to sexual selection, will be

able to judge how far the conclusions at which I have arrived are supported by sufficient evidence. If he

accepts these conclusions he may, I think, safely extend them to mankind; but it would be superfluous here to

repeat what I have so lately said on the manner in which sexual selection apparently has acted on man, both

on the male and female side, causing the two sexes to differ in body and mind, and the several races to differ

from each other in various characters, as well as from their ancient and lowlyorganised progenitors.

He who admits the principle of sexual selection will be led to the remarkable conclusion that the nervous

system not only regulates most of the existing functions of the body, but has indirectly influenced the

progressive development of various bodily structures and of certain mental qualities. Courage, pugnacity,

perseverance, strength and size of body, weapons of all kinds, musical organs, both vocal and instrumental,

bright colours and ornamental appendages, have all been indirectly gained by the one sex or the other,

through the exertion of choice, the influence of love and jealousy, and the appreciation of the beautiful in

sound, colour or form; and these powers of the mind manifestly depend on the development of the brain.

Man scans with scrupulous care the character and pedigree of his horses, cattle, and dogs before he matches

them; but when he comes to his own marriage he rarely, or never, takes any such care. He is impelled by

nearly the same motives as the lower animals, when they are left to their own free choice, though he is in so

far superior to them that he highly values mental charms and virtues. On the other hand he is strongly

attracted by mere wealth or rank. Yet he might by selection do something not only for the bodily constitution

and frame of his offspring, but for their intellectual and moral qualities. Both sexes ought to refrain from

marriage if they are in any marked degree inferior in body or mind; but such hopes are Utopian and will

never be even partially realised until the laws of inheritance are thoroughly known. Everyone does good

service, who aids towards this end. When the principles of breeding and inheritance are better understood, we

shall not hear ignorant members of our legislature rejecting with scorn a plan for ascertaining whether or not

The advancement of the welfare of mankind is a most intricate problem: all ought to refrain from marriage

who cannot avoid abject poverty for their children; for poverty is not only a great evil, but tends to its own

increase by leading to recklessness in marriage. On the other hand, as Mr. Galton has remarked, if the prudent

avoid marriage, whilst the reckless marry, the inferior members tend to supplant the better members of

society. Man, like every other animal, has no doubt advanced to his present high condition through a struggle

for existence consequent on his rapid multiplication; and if he is to advance still higher, it is to be feared that

he must remain subject to a severe struggle. Otherwise he would sink into indolence, and the more gifted men

would not be more successful in the battle of life than the less gifted. Hence our natural rate of increase,

though leading to many and obvious evils, must not be greatly diminished by any means. There should be

open competition for all men; and the most able should not be prevented by laws or customs from succeeding

best and rearing the largest number of offspring. Important as the struggle for existence has been and even

still is, yet as far as the highest part of man's nature is concerned there are other agencies more important. For

the moral qualities are advanced, either directly or indirectly, much more through the effects of habit, the

reasoning powers, instruction, religion, etc., than through natural selection; though to this latter agency may

be safely attributed the social instincts, which afforded the basis for the development of the moral sense.

The main conclusion arrived at in this work, namely, that man is descended from some lowly organised form,

will, I regret to think, be highly distasteful to many. But there can hardly be a doubt that we are descended

from barbarians. The astonishment which I felt on first seeing a party of Fuegians on a wild and broken shore

will never be forgotten by me, for the reflection at once rushed into my mindsuch were our ancestors.

These men were absolutely naked and bedaubed with paint, their long hair was tangled, their mouths frothed

with excitement, and their expression was wild, startled, and distrustful. They possessed hardly any arts, and

like wild animals lived on what they could catch; they had no government, and were merciless to every one

not of their own small tribe. He who has seen a savage in his native land will not feel much shame, if forced

to acknowledge that the blood of some more humble creature flows in his veins. For my own part I would as

soon be descended from that heroic little monkey, who braved his dreaded enemy in order to save the life of

his keeper, or from that old baboon, who descending from the mountains, carried away in triumph his young

comrade from a crowd of astonished dogsas from a savage who delights to torture his enemies, offers up

bloody sacrifices, practices infanticide without remorse, treats his wives like slaves, knows no decency, and is

Man may be excused for feeling some pride at having risen, though not through his own exertions, to the very

summit of the organic scale; and the fact of his having thus risen, instead of having been aboriginally placed

there, may give him hope for a still higher destiny in the distant future. But we are not here concerned with

hopes or fears, only with the truth as far as our reason permits us to discover it; and I have given the evidence

to the best of my ability. We must, however, acknowledge, as it seems to me, that man with all his noble

qualities, with sympathy which feels for the most debased, with benevolence which extends not only to other

men but to the humblest living creature, with his godlike intellect which has penetrated into the movements

and constitution of the solar systemwith all these exalted powersMan still bears in his bodily frame the

In the discussion on Sexual Selection in my 'Descent of Man,' no case interested and perplexed me so much

as the brightlycoloured hinder ends and adjoining parts of certain monkeys. As these parts are more brightly

coloured in one sex than the other, and as they become more brilliant during the season of love, I concluded

that the colours had been gained as a sexual attraction. I was well aware that I thus laid myself open to

ridicule; though in fact it is not more surprising that a monkey should display his brightred hinder end than

that a peacock should display his magnificent tail. I had, however, at that time no evidence of monkeys

exhibiting this part of their bodies during their courtship; and such display in the case of birds affords the best

evidence that the ornaments of the males are of service to them by attracting or exciting the females. I have

lately read an article by Joh. von Fischer, of Gotha, published in 'Der Zoologische Garten,' April 1876, on the

expression of monkeys under various emotions, which is well worthy of study by any one interested in the

subject, and which shews that the author is a careful and acute observer. In this article there is an account of

the behaviour of a young male mandrill when he first beheld himself in a lookingglass, and it is added, that

after a time he turned round and presented his red hinder end to the glass. Accordingly I wrote to Herr J. von

Fischer to ask what he supposed was the meaning of this strange action, and he has sent me two long letters

full of new and curious details, which will, I hope, be hereafter published. He says that he was himself at first

perplexed by the above action, and was thus led carefully to observe several individuals of various other

species of monkeys, which he has long kept in his house. He finds that not only the mandrill (Cynocephalus

mormon) but the drill (C. leucophaeus) and three other kinds of baboons (C. hamadryas, sphinx, and

babouin), also Cynopithecus niger, and Macacus rhesus and nemestrinus, turn this part of their bodies, which

in all these species is more or less brightly coloured, to him when they are pleased, and to other persons as a

sort of greeting. He took pains to cure a Macacus rhesus, which he had kept for five years, of this indecorous

habit, and at last succeeded. These monkeys are particularly apt to act in this manner, grinning at the same

time, when first introduced to a new monkey, but often also to their old monkey friends; and after this mutual

display they begin to play together. The young mandrill ceased spontaneously after a time to act in this

manner towards his master, von Fischer, but continued to do so towards persons who were strangers and to

new monkeys. A young Cynopithecus niger never acted, excepting on one occasion, in this way towards his

master, but frequently towards strangers, and continues to do so up to the present time. From these facts Von

Fischer concludes that the monkeys which behaved in this manner before a lookingglass (viz., the mandrill,

drill, Cynopithecus niger, Macacus rhesus and nemestrinus) acted as if their reflection were a new

acquaintance. The mandrill and drill, which have their hinder ends especially ornamented, display it even

whilst quite young, more frequently and more ostentatiously than do the other kinds. Next in order comes

Cynocephalus hamadryas, whilst the other species act in this manner seldomer. The individuals, however, of

the same species vary in this respect, and some which were very shy never displayed their hinder ends. It

deserves especial attention that Von Fischer has never seen any species purposely exhibit the hinder part of

its body, if not at all coloured. This remark applies to many individuals of Macacus cynomolgus and

Cercocebus radiatus (which is closely allied to M. rhesus), to three species of Cercopithecus and several

American monkeys. The habit of turning the hinder ends as a greeting to an old friend or new acquaintance,

which seems to us so odd, is not really more so than the habits of many savages, for instance that of rubbing

their bellies with their hands, or rubbing noses together. The habit with the mandrill and drill seems to be

instinctive or inherited, as it was followed by very young animals; but it is modified or guided, like so many

other instincts, by observation, for Von Fischer says that they take pains to make their display fully; and if

made before two observers, they turn to him who seems to pay the most attention.

With respect to the origin of the habit, Von Fischer remarks that his monkeys like to have their naked hinder

ends patted or stroked, and that they then grunt with pleasure. They often also turn this part of their bodies to

other monkeys to have bits of dirt picked off, and so no doubt it would be with respect to thorns. But the habit

with adult animals is connected to a certain extent with sexual feelings, for Von Fischer watched through a

glass door a female Cynopithecus niger, and she during several days, "umdrehte und dem Mannchen mit

gurgelnden Tonen die stark gerothete Sitzflache zeigte, was ich fruher nie an diesem Thier bemerkt hatte.

Beim Anblick dieses Gegenstandes erregte sich das Mannchen sichtlich, denn es polterte heftig an den

Staben, ebenfalls gurgelnde Laute ausstossend." As all the monkeys which have the hinder parts of their

bodies more or less brightly coloured live, according to Von Fischer, in open rocky places, he thinks that

these colours serve to render one sex conspicuous at a distance to the other; but, as monkeys are such

gregarious animals, I should have thought that there was no need for the sexes to recognise each other at a

distance. It seems to me more probable that the bright colours, whether on the face or hinder end, or, as in the

mandrill, on both, serve as a sexual ornament and attraction. Anyhow, as we now know that monkeys have

the habit of turning their hinder ends towards other monkeys, it ceases to be at all surprising that it should

have been this part of their bodies which has been more or less decorated. The fact that it is only the monkeys

thus characterised which, as far as at present known, act in this manner as a greeting towards other monkeys

renders it doubtful whether the habit was first acquired from some independent cause, and that afterwards the

parts in question were coloured as a sexual ornament; or whether the colouring and the habit of turning round

were first acquired through variation and sexual selection, and that afterwards the habit was retained as a sign

of pleasure or as a greeting, through the principle of inherited association. This principle apparently comes

into play on many occasions: thus it is generally admitted that the songs of birds serve mainly as an attraction

during the season of love, and that the leks, or great congregations of the blackgrouse, are connected with

their courtship; but the habit of singing has been retained by some birds when they feel happy, for instance by

the common robin, and the habit of congregating has been retained by the black grouse during other seasons

I beg leave to refer to one other point in relation to sexual selection. It has been objected that this form of

selection, as far as the ornaments of the males are concerned, implies that all females within the same district

must possess and exercise exactly the same taste. It should, however, be observed, in the first place, that

although the range of variation of a species may be very large, it is by no means indefinite. I have elsewhere

given a good instance of this fact in the pigeon, of which there are at least a hundred varieties differing

widely in their colours, and at least a score of varieties of the fowl differing in the same kind of way; but the

range of colour in these two species is extremely distinct. Therefore the females of natural species cannot

have an unlimited scope for their taste. In the second place, I presume that no supporter of the principle of

sexual selection believes that the females select particular points of beauty in the males; they are merely

excited or attracted in a greater degree by one male than by another, and this seems often to depend,

especially with birds, on brilliant colouring. Even man, excepting perhaps an artist, does not analyse the

slight differences in the features of the woman whom he may admire, on which her beauty depends. The male

mandrill has not only the hinder end of his body, but his face gorgeously coloured and marked with oblique

ridges, a yellow beard, and other ornaments. We may infer from what we see of the variation of animals

under domestication, that the above several ornaments of the mandrill were gradually acquired by one

individual varying a little in one way, and another individual in another way. The males which were the

handsomest or the most attractive in any manner to the females would pair oftenest, and would leave rather

more offspring than other males. The offspring of the former, although variously intercrossed, would either

inherit the peculiarities of their fathers or transmit an increased tendency to vary in the same manner.

Consequently the whole body of males inhabiting the same country would tend from the effects of constant

intercrossing to become modified almost uniformly, but sometimes a little more in one character and

sometimes in another, though at an extremely slow rate; all ultimately being thus rendered more attractive to

the females. The process is like that which I have called unconscious selection by man, and of which I have

given several instances. In one country the inhabitants value a fleet or light dog or horse, and in another

country a heavier and more powerful one; in neither country is there any selection of individual animals with

lighter or stronger bodies and limbs; nevertheless after a considerable lapse of time the individuals are found

to have been modified in the desired manner almost uniformly, though differently in each country. In two

absolutely distinct countries inhabited by the same species, the individuals of which can never during long

ages have intermigrated and intercrossed, and where, moreover, the variations will probably not have been

identically the same, sexual selection might cause the males to differ. Nor does the belief appear to me

altogether fanciful that two sets of females, surrounded by a very different environment, would be apt to

acquire somewhat different tastes with respect to form, sound, or colour. However this may be, I have given

in my 'Descent of Man' instances of closelyallied birds inhabiting distinct countries, of which the young and

the females cannot be distinguished, whilst the adult males differ considerably, and this may be attributed

Adams, Mr., migration of birds; intelligence of nuthatch; on the Bombycilla carolinensis.

Affection, maternal; manifestation of, by animals; parental and filial, partly the result of natural selection;

Africa, probably the birthplace of man; South, crossed population of; South, retention of colour by the Dutch

in; South, proportion of the sexes in the butterflies of; tattooing practised in; Northern, coiffure of natives of.

Agassiz, L., on conscience in dogs; on the coincidence of the races of man with zoological provinces; on the

number of species of man; on the courtship of the landsnails; on the brightness of the colours of male fishes

during the breeding season; on the frontal protuberance of the males of Geophagus and Cichla; male fishes

hatching ova in their mouths; sexual differences in colour of chromids; on the slight sexual differences of the

Age, in relation to the transmission of characters in birds; variation in accordance with, in birds.

Allen, J.A., vigour of birds earliest hatched; effect of difference of temperature, light, etc., on birds; colours

of birds; on the relative size of the sexes of Callorhinus ursinus; on the name of Otaria jubata; on the pairing

Allen, S., on the habits of Hoplopterus; on the plumes of herons; on the vernal moult of Herodius bubulcus.

America, variation in the skulls of aborigines of; wide range of aborigines of; lice of the natives of; general

America, North, butterflies of; Indians of, women a cause of strife among the; Indians of, their notions of

America, South, character of the natives of; population of parts of; piles of stones in; extinction of the fossil

horse of; desertbirds of; slight sexual difference of the aborigines of; prevalence of infanticide in.

Americans, wide geographical range of; native, variability of; and negroes, difference of; aversion of, to hair

Anderson, Dr., on the tail of Macacus brunneus; the Bufo sikimmensis; sounds of Echis carinata.

Animals, domesticated, more fertile than wild; cruelty of savages to; characters common to man and;

Antelopes, generally polygamous; horns of; canine teeth of some male; use of horns of; dorsal crests in;

Antilope niger, singsing, caama, and gorgon, sexual differences in the colours of.

Ants, large size of the cerebral ganglia in; soldier, large jaws of; playing together; memory in;

intercommunication of, by means of the antennae; habits of; difference of the sexes in; recognition of each

Apes, difference of the young, from the adult; semierect attitude of some; mastoid processes of; influences

of the jawmuscles on the physiognomy of; female, destitute of large canines; building platforms; imitative

faculties of; anthropomorphous; probable speedy extermination of the; Gratiolet on the evolution of; canine

Arabs, fertility of crosses with other races; gashing of cheeks and temples among the.

Ardea ludoviciana, age of mature plumage in; continued growth of crest and plumes in the male of.

Argus pheasant, display of plumage by the male; ocellated spots of the; gradation of characters in the.

Argyll, Duke of, on the physical weakness of man; the fashioning of implements peculiar to man; on the

contest in man between right and wrong; on the primitive civilisation of man; on the plumage of the male

Audubon, J.J., on the pinioned goose; on the speculum of Mergus cucullatus; on the pugnacity of male birds;

on courtship of Caprimulgus; on Tetrao cupido; on Ardea nycticorax; on Sturnella ludoviciana; on the vocal

organs of Tetra cupido; on the drumming of the male Tetrao umbellus; on sounds produced by the nightjar;

on Ardea herodias and Cathartes jota; on Mimus polyglottus; on display in male birds; on the spring change

of colour in some finches; on migration of mocking thrushes; recognition of a dog by a turkey; selection of

mate by female birds; on the turkey; on variation in the male scarlet tanager; on the muskrat; on the habits

of Pyranga aestiva; on local differences in the nests of the same species of birds; on the habits of

woodpeckers; on Bombycilla carolinensis; on young females of Pyranga aestiva acquiring male characters;

on the immature plumage of thrushes; on the immature plumage of birds; on birds breeding in immature

plumage; on the growth of the crest and plume in the male Ardea ludoviciana; on the change of colour in

Australia, not the birthplace of man; halfcastes killed by the natives of; lice of the natives of.

Australians, colour of newborn children of; relative height of the sexes of; women a cause of war among

Aymaras, measurements of the; no grey hair among the; hairlessness of the face in the; long hair of the.

Azara, on the proportion of men and women among the Guaranys; on Palamedea cornuta; on the beards of

the Guaranys; on strife for women among the Guanas; on infanticide; on the eradication of the eyebrows and

eyelashes by the Indians of Paraguay; on polyandry among the Guanas; celibacy unknown among the savages

Baboon, revenge in a; rage excited in, by reading; manifestation of memory by a; employing a mat for shelter

Baboon, effects of intoxicating liquors on; ears of; diversity of the mental faculties in; hands of; habits of;

variability of the tail in; manifestation of maternal affection by; using stones and sticks as weapons;

cooperation of; silence of, on plundering expeditions; apparent polygamy of; polygamous and social habits

Baer, K.E. von, on embryonic development; definition of advancement in the organic scale.

Bagehot, W., on the social virtues among primitive men; slavery formerly beneficial; on the value of

obedience; on human progress; on the persistence of savage tribes in classical times.

Bailly, E.M., on the mode of fighting of the Italian buffalo; on the fighting of stags.

Bain, A., on the sense of duty; aid springing from sympathy; on the basis of sympathy; on the love of

Baird, W., on a difference in colour between the males and females of some Entozoa.

Baker, Sir S., on the fondness of the Arabs for discordant music; on sexual difference in the colours of an

antelope; on the elephant and rhinoceros attacking white or grey horses; on the disfigurements practised by

the negroes; on the gashing of the cheeks and temples practised in Arab countries; on the coiffure of the

North Africans; on the perforation of the lower lip by the women of Latooka; on the distinctive characters of

Barrington, Daines, on the language of birds; on the clucking of the hen; on the object of the song of birds; on

the singing of female birds; on birds acquiring the songs of other birds; on the muscles of the larynx in

Bartlett, A.D., period of hatching of bird's eggs; on the tragopan; on the development of the spurs in

Crossoptilon auritum; on the fighting of the males of Plectopterus gambensis; on the Knot; on display in male

birds; on the display of plumage by the male Polyplectron; on Crossoptilon auritum and Phasianus Wallichii;

on the habits of Lophophorus; on the colour of the mouth in Buceros bicornis; on the incubation of the

cassowary; on the Cape Buffalo; on the use of the horns of antelopes; on the fighting of male warthogs; on

Ammotragus tragelaphus; on the colours of Cercopithecus cephus; on the colours of the faces of monkeys; on

Bate, C.S., on the superior activity of male crustacea; on the proportions of the sexes in crabs; on the chelae

of crustacea; on the relative size of the sexes in crustacea; on the colours of crustacea.

Bates, H.W., on variation in the form of the head of Amazonian Indians; on the proportion of the sexes

among Amazonian butterflies; on sexual differences in the wings of butterflies; on the fieldcricket; on

Pyrodes pulcherrimus; on the horns of Lamellicorn beetles; on the colours of Epicaliae, etc.; on the coloration

of tropical butterflies; on the variability of Papilio Sesostris and Childrenae; on male and female butterflies

inhabiting different stations; on mimicry; on the caterpillar of a Sphinx; on the vocal organs of the

Bats, scentglands; sexual differences in the colour of; fur of male frugivorous.

Beard, development of, in man; analogy of the, in man and the quadrumana; variation of the development of

the, in different races of men; estimation of, among bearded nations; probable origin of the.

Beauty, sense of, in animals; appreciation of, by birds; influence of; variability of the standard of.

Bechstein, on female birds choosing the best singers among the males; on rivalry in songbirds; on the

singing of female birds; on birds acquiring the songs of other birds; on pairing the canary and siskin; on a

Bees, pollenbaskets and stings of; destruction of drones and queens by; female, secondary sexual characters

of; proportion of sexes; difference of the sexes in colour and sexual selection.

Beetles, size of the cerebral ganglia in; dilatation of the foretarsi in male; blind; stridulation of.

Bell, T., on the numerical proportion of the sexes in moles; on the newts; on the croaking of the frog; on the

difference in the coloration of the sexes in Zootoca vivipara; on moles fighting.

Belt, Mr., on the nakedness of tropical mankind; on a spidermonkey and eagle; habits of ants; Lampridae

distasteful to mammals; mimicry of Leptalides; colours of Nicaraguan frogs; display of hummingbirds; on

Birds, imitations of the songs of other birds by; dreaming; killed by telegraph wires; language of; sense of

beauty in; pleasure of, in incubation; male, incubation by; and reptiles, alliance of; sexual differences in the

beak of some; migratory, arrival of the male before the female; apparent relation between polygamy and

marked sexual differences in; monogamous, becoming polygamous under domestication; eagerness of male

in pursuit of the female; wild, numerical proportion of the sexes in; secondary sexual characters of; difference

of size in the sexes of; fights of male, witnessed by females; display of male, to captivate the females; close

attention of, to the songs of others; acquiring the song of their fosterparents; brilliant, rarely good songsters;

loveantics and dances of; coloration of; moulting of; unpaired; male, singing out of season; mutual affection

of; in confinement, distinguish persons; hybrid, production of; Albino; European, number of species of;

variability of; geographical distribution of colouring; gradation of secondary sexual characters in; obscurely

coloured, building concealed nests; young female, acquiring male characters; breeding in immature plumage;

moulting of; aquatic, frequency of white plumage in; vocal courtship of; naked skin of the head and neck in.

Births, numerical proportions of the sexes in, in animals and man; male and female, numerical proportion of,

Bischoff, Prof., on the agreement between the brains of man and of the orang; figure of the embryo of the

dog; on the convolutions of the brain in the human foetus; on the difference between the skulls of man and

Bishop, J., on the vocal organs of frogs; on the vocal organs of cervine birds; on the trachea of the Merganser.

Blackbird, sexual differences in the; proportion of the sexes in the; acquisition of a song by; colour of the

beak in the sexes of the; pairing with a thrush; colours and nidification of the; young of the; sexual difference

Blackcock, polygamous; proportion of the sexes in the; pugnacity and lovedance of the; call of the;

moulting of the; duration of the courtship of the; and pheasant, hybrids of; sexual difference in coloration of

Blackwall, J., on the speaking of the magpie; on the desertion of their young by swallows; on the superior

activity of male spiders; on the proportion of the sexes in spiders; on sexual variation of colour in spiders; on

Blakiston, Captain, on the American snipe; on the dances of Tetrao phasianellus.

Blumenbach, on Man; on the large size of the nasal cavities in American aborigines; on the position of man;

Blyth, E., on the structure of the hand in the species of Hylobates; observations on Indian crows; on the

development of the horns in the Koodoo and Eland antelopes; on the pugnacity of the males of Gallicrex

cristatus; on the presence of spurs in the female Euplocamus erythrophthalmus; on the pugnacity of the

amadavat; on the spoonbill; on the moulting of Anthus; on the moulting of bustards, plovers, and Gallus

bankiva; on the Indian honeybuzzard; on sexual differences in the colour of the eyes of hornbills; on Oriolus

melanocephalus; on Palaeornis javanicus; on the genus Ardetta; on the peregrine falcon; on young female

birds acquiring male characters; on the immature plumage of birds; on representative species of birds; on the

young of Turnix; on anomalous young of Lanius rufus and Colymbus glacialis; on the sexes and young of the

sparrows; on dimorphism in some herons; on the ascertainment of the sex of nestling bullfinches by pulling

out breastfeathers; on orioles breeding in immature plumage; on the sexes and young of Buphus and

Anastomus; on the young of the blackcap and blackbird; on the young of the stonechat; on the white plumage

of Anastomus; on the horns of Bovine animals; on the horns of Antilope bezoartica; on the mode of fighting

of Ovis cycloceros; on the voice of the Gibbons; on the crest of the male wild goat; on the colours of Portax

picta; on the colours of Antilope bezoartica; on the colour of the Axis deer; on sexual difference of colour in

Hylobates hoolock; on the hogdeer; on the beard and whiskers in a monkey, becoming white with age.

Boitard and Corbie, MM., on the transmission of sexual peculiarities in pigeons; on the antipathy shewn by

Boner, C., on the transfer of male characters to an old female chamois; on the habits of stags; on the pairing

Bory St. Vincent, on the number of species of man; on the colours of Labrus pavo.

Brain, of man, agreement of the, with that of lower animals; convolutions of, in the human foetus; influence

of development of mental faculties upon the size of the; influence of the development of on the spinal column

and skull; larger in some existing mammals than in their tertiary prototypes; relation of the development of

the, to the progress of language; disease of the, affecting speech; difference in the convolutions of, in

different races of men; supplement on, by Prof. Huxley; development of the gyri and sulci.

Braubach, Prof., on the quasireligious feeling of a dog towards his master; on the selfrestraint of dogs.

Brazil, skulls found in caves of; population of; compression of the nose by the natives of.

Brehm, on the effects of intoxicating liquors on monkeys; on the recognition of women by male Cynocephali;

on the diversity of the mental faculties of monkeys; on the habits of baboons; on revenge taken by monkeys;

on manifestations of maternal affection by monkeys and baboons; on the instinctive dread of monkeys for

serpents; on the use of stones as missiles by baboons; on a baboon using a mat for shelter from the sun; on the

signalcries of monkeys; on sentinels posted by monkeys; on cooperation of animals; on an eagle attacking

a young Cercopithecus; on baboons in confinement protecting one of their number from punishment; on the

habits of baboons when plundering; on polygamy in Cynocephalus and Cebus; on the numerical proportion

of the sexes in birds; on the lovedance of the blackcock; Palamedea cornuta; on the habits of the

Blackgrouse; on sounds produced by birds of paradise; on assemblages of grouse; on the finding of new

mates by birds; on the fighting of wild boars; on sexual differences in Mycetes; on the habits of

Broca, Prof., on the occurrence of the supracondyloid foramen in the human humerus; anthropomorphous

apes more bipedal than quadrupedal; on the capacity of Parisian skulls at different periods; comparison of

modern and mediaeval skulls; on tails of quadrupeds; on the influence of natural selection; on hybridity in

man; on human remains from Les Eyzies; on the cause of the difference between Europeans and Hindoos.

Brown, R., sentinels of seals generally females; on the battles of seals; on the narwhal; on the occasional

absence of the tusks in the female walrus; on the bladdernose seal; on the colours of the sexes in Phoca

Groenlandica; on the appreciation of music by seals; on plants used as lovephilters, by North American

BrownSequard, Dr., on the inheritance of the effects of operations by guineapig.

Brulerie, P. de la, on the habits of Ateuchus cicatricosus; on the stridulation of Ateuchus.

Buceros bicornis, sexual differences in the colouring of the casque, beak, and mouth in.

Buchner, L., on the origin of man; on the use of the human foot as a prehensile organ; on the mode of

Buckland, F., on the numerical proportion of the sexes in rats; on the proportion of the sexes in the trout; on

Buist, R., on the proportion of the sexes in salmon; on the pugnacity of the male salmon.

Bullfinch, sexual differences in the; piping; female, singing of the; courtship of the; widowed, finding a new

mate; attacking a reedbunting; nestling, sex ascertained by pulling out breast feathers.

Burchell, Dr., on the zebra; on the extravagance of a Bushwoman in adorning herself; celibacy unknown

Burton, Captain, on negro ideas of female beauty; on a universal ideal of beauty.

Bustard, throatpouch of the male; humming noise produced by a male; Indian, eartufts of.

Bustards, occurrence of sexual differences and of polygamy among the; lovegestures of the male; double

Butler, A.G., on sexual differences in the wings of Aricoris epitus; courtship of butterflies; on the colouring

of the sexes in species of Thecla; on the resemblance of Iphias glaucippe to a leaf; on the rejection of certain

Butterfly, noise produced by a; Emperor; meadow brown, instability of the ocellated spots of.

Butterflies, proportion of the sexes in; forelegs atrophied in some males; sexual difference in the neuration of

the wings of; pugnacity of male; protective resemblances of the lower surface of; display of the wings by;

white, alighting upon bits of paper; attracted by a dead specimen of the same species; courtship of; male and

Campbell, J., on the Indian elephant; on the proportion of male and female births in the harems of Siam.

Canary, polygamy of the; change of plumage in, after moulting; female, selecting the best singing male;

sterile hybrid, singing of a; female, singing of the; selecting a greenfinch; and siskin, pairing of.

Canestrini, G., on rudimentary characters and the origin of man; on rudimentary characters; on the movement

of the ear in man; of the variability of the vermiform appendage in man; on the abnormal division of the

malar bone in man; on abnormal conditions of the human uterus; on the persistence of the frontal suture in

man; on the proportion of the sexes in silkmoths; secondary sexual characters of spiders.

Canine teeth in man, diminution of, in man; diminution of, in horses; disappearance of, in male ruminants;

Capercailzie, polygamous; proportion of the sexes in the; pugnacity of the male; pairing of the; autumn

meetings of the; call of the; duration of the courtship of; behaviour of the female; inconvenience of black

colour to the female; sexual difference in the coloration of the; crimson eyecere of the male.

Carbonnier, on the natural history of the pike; on the relative size of the sexes in fishes; courtship of Chinese

Carus, Prof. V., on the development of the horns in merino sheep; on antlers of red deer.

Cat, convoluted body in the extremity of the tail of a; sick, sympathy of a dog with a.

Catlin, G., correlation of colour and texture of hair in the Mandans; on the development of the beard among

the North American Indians; on the great length of the hair in some North American tribes.

Caton, J.D., on the development of the horns in Cervus virginianus and strongyloceros; on the wild turkey; on

the presence of traces of horns in the female wapiti; on the fighting of deer; on the crest of the male wapiti;

on the colours of the Virginian deer; on sexual differences of colour in the wapiti; on the spots of the

Cattle, rapid increase of, in South America; domestic, lighter in winter in Siberia; horns of; domestic, sexual

Caudal vertebrae, number of, in macaques and baboons; basal, of monkeys, imbedded in the body.

Cebus Azarae, liability of, to the same diseases as man; distinct sounds produced by; early maturity of the

Cebus capucinus, polygamous; sexual differences of colour in; hair on the head of.

Cercopithecus, young, seized by an eagle and rescued by the troop; definition of species of.

Cervus canadensis, traces of horns in the female; attacking a man; sexual difference in the colour of.

Cervus elaphus, battles of male; horns of, with numerous points; long hairs on the throat of.

Chapuis, Dr., on the transmission of sexual peculiarities in pigeons; on streaked Belgian pigeons.

Characters, male, developed in females; secondary sexual, transmitted through both sexes; natural, artificial,

Chest, proportions of, in soldiers and sailors; large, of the Quechua and Aymara Indians.

Chimpanzee, ears of the; representatives of the eyebrows in the; hands of the; absence of mastoid processes

in the; platforms built by the; cracking nuts with a stone; direction of the hair on the arms of the; supposed

Chinese, use of flint tools by the; difficulty of distinguishing the races of the; colour of the beard in; general

beardlessness of the; opinions of the, on the appearance of Europeans and Cingalese; compression of the feet

Civilisation, effects of, upon natural selection; influence of, in the competition of nations.

Climate, cool, favourable to human progress; power of supporting extremes of, by man; want of connexion

Coccyx, in the human embryo; convoluted body at the extremity of the; imbedded in the body.

Cock, blind, fed by its companion; game, killing a kite; comb and wattles of the; preference shewn by the, for

Collingwood, C., on the pugnacity of the butterflies of Borneo; on butterflies being attracted by a dead

Colour, supposed to be dependent on light and heat; correlation of, with immunity from certain poisons and

parasites; purpose of, in lepidoptera; relation of, to sexual functions, in fishes; difference of, in the sexes of

snakes; sexual differences of, in lizards; influence of, in the pairing of birds of different species; relation of,

to nidification; sexual differences of, in mammals; recognition of, by quadrupeds; of children, in different

Colours, admired alike by man and animals; bright, due to sexual selection; bright, among the lower animals;

bright, protective to butterflies and moths; bright, in male fishes; transmission of, in birds.

Conditions of life, action of changed, upon man; influence of, on plumage of birds.

Cotingidae, sexual differences in; coloration of the sexes of; resemblance of the females of distinct species of.

Courage, variability of, in the same species; universal high appreciation of; importance of; characteristic of

Crotch, G.R., on the stridulation of beetles; on the stridulation of Heliopathes; on the stridulation of Acalles;

Crustacea, parasitic, loss of limbs by female; prehensile feet and antennae of; male, more active than female;

parthenogenesis in; secondary sexual characters of; amphipod, males sexually mature while young; auditory

Cupples, Mr., on the numerical proportion of the sexes in dogs, sheep, and cattle; on the Scotch deerhound;

Curculionidae, sexual difference in length of snout in some; hornlike processes in male; musical.

Cuvier, G., on the number of caudal vertebrae in the mandrill; on instinct and intelligence; views of, as to the

Cynocephalus, difference of the young from the adult; male, recognition of women by; polygamous habits of

Davis, J.B., on the capacity of the skull in various races of men; on the beards of the Polynesians.

Deer, development of the horns in; spots of young; horns of; use of horns of; horns of a, in course of

modification; size of the horns of; female, pairing with one male whilst others are fighting for her; male,

Denison, Sir W., manner of ridding themselves of vermin among the Australians; extinction of Tasmanians.

Desmarest, on the absence of suborbital pits in Antilope subgutturosa; on the whiskers of Macacus; on the

colour of the opossum; on the colours of the sexes of Mus minutus; on the colouring of the ocelot; on the

colours of seals; on Antilope caama; on the colours of goats; on sexual difference of colour in Ateles

Digits, supernumerary, more frequent in men than in women; supernumerary, inheritance of; supernumerary,

Diseases, common to man and the lower animals; difference of liability to, in different races of men; new,

Distribution, wide, of man; geographical, as evidence of specific distinctness in man.

Disuse, effects of, in producing rudimentary organs; and use of parts, effects of; of parts, influence of, on the

Dixon, E.S., on the pairing of different species of geese; on the courtship of peafowl.

Dogs, suffering from tertian ague; memory of; dreaming; diverging when drawing sledges over thin ice;

exercise of reasoning faculties by; domestic, progress of, in moral qualities; distinct tones uttered by;

parallelism between his affection for his master and religious feeling; sociability of the; sympathy of, with a

sick cat; sympathy of, with his master; their possession of conscience; possible use of the hair on the

forelegs of the; races of the; numerical proportion of male and female births in; sexual affection between

D'Orbigny, A., on the influence of dampness and dryness on the colour of the skin; on the Yuracaras.

Doubleday, H., on the proportion of the sexes in the smaller moths; males of Lasiocampa quercus and on the

attraction of the Saturnia carpini by the female; on the proportion of the sexes in the Lepidoptera; on the

ticking of Anobium tesselatum; on the structure of Ageronia feronia; on white butterflies alighting upon

Douglas, J.W., on the sexual differences of the Hemiptera; colours of British Homoptera.

Dragonflies, caudal appendages of male; relative size of the sexes of; difference in the sexes of; want of

Duck, wild, sexual differences in the; speculum and male characters of; pairing with a pintail drake.

Ducks, wild, becoming polygamous under partial domestication; dogs and cats recognised by.

Duncan, Dr., on the fertility of early marriages; comparative health of married and single.

Dupont, M., on the occurrence of the supracondyloid foramen in the humerus of man.

Dureau de la Malle, on the songs of birds; on the acquisition of an air by blackbirds.

Ear, motion of the; external shell of the, useless in man; rudimentary point of the, in man.

Ecker, figure of the human embryo; on the development of the gyri and sulci of the brain; on the sexual

differences in the pelvis in man; on the presence of a sagittal crest in Australians.

Edentata, former wide range of, in America; absence of secondary sexual characters in.

Edwards, Mr., on the proportion of the sexes in North American species of Papilio.

Egerton, Sir P., on the use of the antlers of deer; on the pairing of red deer; on the bellowing of stags.

Elephant, rate of increase of the; nakedness of the; using a fan; Indian, forbearance to his keeper; polygamous

habits of the; pugnacity of the male; tusks of; Indian, mode of fighting of the; male, odour emitted by the;

Elliot, R., on the numerical proportion of the sexes in young rats; on the proportion of the sexes in sheep.

Elphinstone, Mr., on local difference of stature among the Hindoos; on the difficulty of distinguishing the

Emotions experienced by the lower animals in common with man; manifested by animals.

Eschricht, on the development of hair in man; on a languinous moustache in a female foetus; on the want of

definition between the scalp and the forehead in some children; on the arrangement of the hair in the human

Esquimaux, their belief in the inheritance of dexterity in sealcatching; mode of life of.

Europeans, difference of, from Hindoos; hairiness of, probably due to reversion.

Eye, destruction of the; change of position in; obliquity of, regarded as a beauty by the Chinese and Japanese.

Eyebrows, elevation of; development of long hairs in; in monkeys; eradicated in parts of South America and

Eyes, pillared, of the male of Chloeon; difference in the colour of, in the sexes of birds.

Faculties, diversity of, in the same race of men; inheritance of; diversity of, in animals of the same species;

Falconer, H., on the mode of fighting of the Indian elephant; on canines in a female deer; on Hyomoschus

Farr, Dr., on the effects of profligacy; on the influence of marriage on mortality.

Farrar, F.W., on the origin of language; on the crossing or blending of languages; on the absence of the idea

of God in certain races of men; on early marriages of the poor; on the middle ages.

Faye, Prof., on the numerical proportion of male and female births in Norway and Russia; on the greater

Feathers, modified, producing sounds; elongated, in male birds; racketshaped; barbless and with

Feeding, high, probable influence of, in the pairing of birds of different species.

Females, presence of rudimentary male organs in; preference of, for certain males; pursuit of, by males;

Females and males, comparative numbers of; comparative mortality of, while young.

Fijians, burying their old and sick parents alive; estimation of the beard among the; admiration of, for a broad

Fishes, kidneys of, represented by Corpora Wolffiana in the human embryo; male, hatching ova in their

mouths; receptacles for ova possessed by; relative size of the sexes in; freshwater, of the tropics; protective

resemblances in; change of colour in; nestbuilding; spawning of; sounds produced by; continued growth of.

Flower, W.H., on the abductor of the fifth metatarsal in apes; on the position of the Seals; on the Pithecia

Foot, prehensile power of the, retained in some savages; prehensile, in the early progenitors of man.

Foramen, supracondyloid, exceptional occurrence of in the humerus of man; in the early progenitors of man.

Forbes, D., on the Aymara Indians; on local variation of colour in the Quichuas; on the hairlessness of the

Fowl, occurrence of spurs in the female; game, early pugnacity of; Polish, early development of cranial

peculiarities of; variations in plumage of; examples of correlated development in the; domestic, breeds and

Fowls, spangled Hamburg; inheritance of changes of plumage by; sexual peculiarities in, transmitted only to

the same sex; loss of secondary sexual characters by male; Polish, origin of the crest in; period of inheritance

of characters by; cuckoo; development of the comb in; numerical proportion of the sexes in; courtship of;

mongrel, between a black Spanish cock and different hens; pencilled Hamburg, difference of the sexes in;

Fox, W.D., on some halftamed wild ducks becoming polygamous, and on polygamy in the guineafowl and

canarybird; on the proportion of the sexes in cattle; on the pugnacity of the peacock; on a nuptial assembly

of magpies; on the finding of new mates by crows; on partridges living in triplets; on the pairing of a goose

Frogs, male; temporary receptacles for ova possessed by; ready to breed before the females; fighting of; vocal

Fuegians, difference of stature among the; power of sight in the; skill of, in stonethrowing; resistance of the,

to their severe climate; mental capacity of the; quasireligious sentiments of the; resemblance of, in mental

characters, to Europeans; mode of life of the; aversion of, to hair on the face; said to admire European

Gallicrex cristatus, pugnacity of male; red carbuncle occurring in the male during the breedingseason.

Gallinaceae, frequency of polygamous habits and of sexual differences in the; lovegestures of; decomposed

feathers in; stripes of young; comparative sexual differences between the species of; plumage of.

Galton, Mr., on hereditary genius; gregariousness and independence in animals; on the struggle between the

social and personal impulses; on the effects of natural selection on civilised nations; on the sterility of sole

daughters; on the degree of fertility of people of genius; on the early marriages of the poor; on the ancient

Greeks; on the Middle Ages; on the progress of the United States; on South African notions of beauty.

Geese, clanging noise made by; pairing of different species of; Canada, selection of mates by.

Gegenbaur, C., on the number of digits in the Ichthyopterygia; on the hermaphroditism of the remote

Gelasimus, proportions of the sexes in a species of; use of the enlarged chelae of the male; pugnacity of

males of; rational actions of a; difference of colour in the sexes of a species of.

Geoffroy St.Hilaire, Isid., on the recognition of women by male quadrumana; on monstrosities;

coincidences of arrested development with polydactylism; on animallike anomalies in the human structure;

on the correlation of monstrosities; on the distribution of hair in man and monkeys; on the caudal vertebrae of

monkeys; on correlated variability; on the classification of man; on the long hair on the heads of species of

Semnopithecus; on the hair in monkeys; on the development of horns in female deer; and F. Cuvier, on the

Geophagus, frontal protuberance of, male; eggs hatched by the male, in the mouth or branchial cavity.

Giard, M., disputes descent of vertebrates from Ascidians; colour of sponges and Ascidians; musky odour of

Goat, male, wild, falling on his horns; male, odour emitted by; male, wild, crest of the; Berbura, mane,

Goats, sexual differences in the horns of; horns of; mode of fighting of; domestic, sexual differences of, late

Godron, M., on variability; on difference of stature; on the want of connexion between climate and the colour

Goldfinch, proportion of the sexes in the; sexual differences of the beak in the; courtship of the.

Gorilla, semierect attitude of the; mastoid processes of the; protecting himself from rain with his hands;

manner of sitting; supposed to be a kind of mandrill; polygamy of the; voice of the; cranium of; fighting of

Gould, B.A., on variation in the length of the legs in man; measurements of American soldiers; on the

proportions of the body and capacity of the lungs in different races of men; on the inferior vitality of

Gould, J., on migration of swifts; on the arrival of male snipes before the females; on the numerical

proportion of the sexes in birds; on Neomorpha Grypus; on the species of Eustephanus; on the Australian

muskduck; on the relative size of the sexes in Briziura lobata and Cincloramphus cruralis; on Lobivanellus

lobatus; on habits of Menura Alberti; on the rarity of song in brilliant birds; on Selasphorus platycerus; on the

Bowerbirds; on the ornamental plumage of the Hummingbirds; on the moulting of the ptarmigan; on the

display of plumage by the male Hummingbirds; on the shyness of adorned male birds; on the decoration of

the bowers of Bowerbirds; on the decoration of their nest by Hummingbirds; on variation in the genus

Cynanthus; on the colour of the thighs in a male parrakeet; on Urosticte Benjamini; on the nidification of the

Orioles; on obscurelycoloured birds building concealed nests; on trogons and kingfishers; on Australian

parrots; on Australian pigeons; on the moulting of the ptarmigan; on the immature plumage of birds; on the

Australian species of Turnix; on the young of Aithurus polytmus; on the colours of the bills of toucans; on

the relative size of the sexes in the marsupials of Australia; on the colours of the Marsupials.

Gratiolet, Prof., on the anthropomorphous apes; on the evolution of the anthropomorphous apes; on the

Gray, J.E., on the caudal vertebrae of monkeys; on the presence of rudiments of horns in the female of

Cervulus moschatus; on the horns of goats and sheep; on crests of male antelopes; on the beard of the ibex;

on the Berbura goat; on sexual differences in the coloration of Rodents; ornaments of male sloth; on the

colours of the Elands; on the Singsing antelope; on the colours of goats; on Lemur Macaco; on the

Greg, W.R., on the effects of natural selection on civilised nations; on the early marriages of the poor; on the

Greyhounds, numerical proportion of the sexes in; numerical proportion of male and female births in.

Grouse, red, monogamous; pugnacity of young male; producing a sound by beating their wings together;

Gruber, Dr., on the occurrence of the supracondyloid foramen in the humerus of man; on division of malar

Guaranys, proportion of men and women among; colour of newborn children of the; beards of the.

Gunther, Dr., on paddle of Ceradotus; on hermaphroditism in Serranus; on male fishes hatching ova in their

mouths; on mistaking infertile female fishes for males; on the prehensile organs of male Plagiostomous

fishes; spines and brushes on fishes; on the pugnacity of the male salmon and trout; on the relative size of the

sexes in fishes; on sexual differences in fishes; on the genus Callionymus; on a protective resemblance of a

pipefish; on the genus Solenostoma; on the coloration of frogs and toads; combat of Testudo elegans; on the

Haeckel, E., on the origin of man; on rudimentary characters; on death caused by inflammation of the

vermiform appendage; on the canine teeth in man; on the steps by which man became a biped; on man as a

member of the Catarrhine group; on the position of the Lemuridae; on the genealogy of the Mammalia; on the

lancelet; on the transparency of pelagic animals; on the musical powers of women.

Hair, development of, in man; character of, supposed to be determined by light and heat; distribution of, in

man; possibly removed for ornamental purposes; arrangement and direction of; of the early progenitors of

man; different texture of, in distinct races; and skin, correlation of colour of; development of, in mammals;

management of, among different peoples; great length of, in some North American tribes; elongation of the,

Hamilton, C., on the cruelty of the Kaffirs to animals; on the engrossment of the women by the Kaffir chiefs.

Hands, larger at birth, in the children of labourers; structure of, in the quadrumana; and arms, freedom of,

Harris, T.W., on the Katydid locust; on the stridulation of the grasshoppers; on Oecanthus nivalis; on the

Haymond, R., on the drumming of the male Tetrao umbellus; on the drumming of birds.

Head, altered position of, to suit the erect attitude of man; hairiness of, in man; processes of, in male beetles;

Hearne, on strife for women among the North American Indians; on the North American Indians' notion of

Helmholtz, on pleasure derived from harmonies; on the human eye; on the vibration of the auditory hairs of

Herons, lovegestures of; decomposed feathers in; breeding plumage of; young of the; sometimes dimorphic;

continued growth of crest and plumes in the males of some; change of colour in some.

Hewitt, Mr., on a gamecock killing a kite; on the recognition of dogs and cats by ducks; on the pairing of a

wild duck with a pintail drake; on the courtship of fowls; on the coupling of pheasants with common hens.

Hindoos, local difference of stature among; difference of, from Europeans; colour of the beard in.

Hoffberg, on the horns of the reindeer; on sexual preferences shewn by reindeer.

Hooker, Dr., forbearance of elephant to his keeper; on the colour of the beard in man.

Hornbills, sexual difference in the colour of the eyes in; nidification and incubation of.

Horns, sexual differences of, in sheep and goats; loss of, in female merino sheep; development of, in deer;

development in antelopes; from the head and thorax, in male beetles; of deer; originally a masculine character

Horse, fossil, extinction of the, in South America; polygamous; canine teeth of male; winter change of colour.

Horses, rapid increase of, in South America; diminution of canine teeth in; dreaming; of the Falkland Islands

and Pampas; numerical proportion of the sexes, in; lighter in winter in Siberia; sexual preferences in; pairing

preferently with those of the same colour; numerical proportion of male and female births in; formerly

Hottentots, lice of; readily become musicians; notions of female beauty of the; compression of nose by.

Hough, Dr. S., men's temperature more variable than women's; proportion of sexes in man.

Houzeau, on the baying of the dog; on reason in dogs; birds killed by telegraph wires; on the cries of

domestic fowls and parrots; animals feel no pity; suicide in the Aleutian Islands.

Huber, P., on ants playing together; on memory in ants; on the intercommunication of ants; on the recognition

Humboldt, A. von, on the rationality of mules; on a parrot preserving the language of a lost tribe; on the

cosmetic arts of savages; on the exaggeration of natural characters by man; on the red painting of American

Hummingbird, racketshaped feathers in the tail of a; display of plumage by the male.

Hummingbirds, ornament their nests; polygamous; proportion of the sexes in; sexual differences in;

pugnacity of male; modified primaries of male; coloration of the sexes of; display by; nidification of the;

Hunter, J., on the number of species of man; on secondary sexual characters; on the general behaviour of

female animals during courtship; on the muscles of the larynx in songbirds; on strength of males; on the

Huxley, T.H., on the structural agreement of man with the apes; on the agreement of the brain in man with

that of lower animals; on the adult age of the orang; on the embryonic development of man; on the origin of

man; on variation in the skulls of the natives of Australia; on the abductor of the fifth metatarsal in apes; on

the nature of the reasoning power; on the position of man; on the suborders of primates; on the Lemuridae; on

the Dinosauria; on the amphibian affinities of the Ichthyosaurians; on variability of the skull in certain races

Hylobates, absence of the thumb in; upright progression of some species of; maternal affection in a; direction

Hylobates agilis, hair on the arms of; musical voice of the; superciliary ridge of; voice of.

Hymonoptera, large size of the cerebral ganglia in; classification of; sexual differences in the wings of;

Ibis, white, change of colour of naked skin in, during the breeding season; scarlet, young of the.

Idiots, microcephalous, their characters and habits; hairiness and animal nature of their actions;

Imitation, of man by monkeys; tendency to, in monkeys,; microcephalous idiots and savages; influence of.

India, difficulty of distinguishing the native races of; Cyprinidae of; colour of the beard in races of men of.

Inheritance, of long and short sight; of effects of use of vocal and mental organs; of moral tendencies; laws

Insects, relative size of the cerebral ganglia in; male, appearance of, before the females; pursuit of female, by

the males; period of development of sexual characters in; secondary sexual characters of; kept in cages;

Instincts, complex origin of, through natural selection; possible origin of some; acquired, of domestic

animals; variability of the force of; difference of force between the social and other; utilised for new

Intellectual faculties, their influence on natural selection in man; probably perfected through natural selection.

Jaeger, Dr., length of bones increased from carrying weights; on the difficulty of approaching herds of wild

Janson, E.W., on the proportions of the sexes in Tomicus villosus; on stridulant beetles.

Jaws, smaller proportionately to the extremities; influence of food upon the size of; diminution of, in man; in

Jeffreys, J. Gwyn, on the form of the shell in the sexes of the Gasteropoda; on the influence of light upon the

Jenner, Dr., on the voice of the rook; on the finding of new mates by magpies; on retardation of the

Jenyns, L., on the desertion of their young by swallows; on male birds singing after the proper season.

Jerdon, Dr., on birds dreaming; on the pugnacity of the male bulbul; on the pugnacity of the male Ortygornis

gularis; on the spurs of Galloperdix; on the habits of Lobivanellus; on the spoonbill; on the drumming of the

Kalijpheasant; on Indian bustards; on Otis bengalensis; on the eartufts of Sypheotides auritus; on the

double moults of certain birds; on the moulting of the honeysuckers; on the moulting of bustards, plovers,

and drongos; on the spring change of colour in some finches; on display in male birds; on the display of the

undertail coverts by the male bulbul; on the Indian honeybuzzard; on sexual differences in the colour of

the eyes of hornbills; on the markings of the Tragopan pheasant; on the nidification of the Orioles; on the

nidification of the hornbills; on the Sultan yellowtit; on Palaeornis javanicus; on the immature plumage of

birds; on representative species of birds; on the habits of Turnix; on the continued increase of beauty of the

Jews, ancient use of flint tools by the; uniformity of, in various parts of the world; numerical proportion of

Kaffirs, their cruelty to animals; lice of the; colour of the; engrossment of the handsomest women by the

Kulmucks, general beardlessness of; aversion of, to hairs on the face; marriagecustoms of the.

Kent, W.S., elongation of dorsal fin of Callionymus lyra; courtship of Labrus mixtus; colours and courtship

King, W.R., on the vocal organs of Tetrao cupido; on the drumming of grouse; on the reindeer; on the

Kingfishers, colours and nidification of the; immature plumage of the; young of the.

Kirby and Spence, on sexual differences in the length of the snout in Curculionidae; on the courtship of

insects; on the elytra of Dytiscus; on peculiarities in the legs of male insects; on the relative size of the sexes

in insects; on the Fulgoridae; on the habits of the Termites; on difference of colour in the sexes of beetles; on

the horns of the male lamellicorn beetles; on hornlike processes in male Curculionidae; on the pugnacity of

Knox, R., on the semilunar fold; on the occurrence of the supracondyloid foramen in the humerus of man;

Kovalevsky, W., on the pugnacity of the male capercailzie; on the pairing of the capercailzie.

Krause, on a convoluted body at the extremity of the tail in a Macacus and a cat.

Lamellicorn beetles, hornlike processes from the head and thorax of; influence of sexual selection on.

Lamont, Mr., on the tusks of the walrus; on the use of its tusks by the walrus; on the bladdernose seal.

Landois, H., gnats attracted by sound; on the production of sound by the Cicadae; on the stridulating organ of

the crickets; on Decticus; on the stridulating organs of the Acridiidae; stridulating apparatus, in Orthoptera;

on the stridulation of Necrophorus; on the stridulant organ of Cerambyx heros; on the stridulant organ of

Geotrupes; on the stridulating organs in the Cleoptera; on the ticking of Anobium.

Language, an art; articulate, origin of; relation of the progress of, to the development of the brain; effects of

inheritance in production of; complex structure of, among barbarous nations; natural selection in; gesture;

Languages, presence of rudiments in; classification of; variability of; crossing or blending of; complexity of,

no test of perfection or proof of special creation; resemblance of, evidence of community of origin.

Lankester, E.R., on comparative longevity; on the destructive effects of intemperance.

Lartet, E., comparison of cranial capacities of skulls of recent and tertiary mammals; on the size of the brain

Lasiocampa quercus, attraction of males by the female; sexual difference of colour in.

Lawrence, W., on the superiority of savages to Europeans in power of sight; on the colour of negro infants;

on the fondness of savages for ornaments; on beardless races; on the beauty of the English aristocracy.

Layard, E.L., on the instance of rationality in a cobra; on the pugnacity of Gallus Stanleyi.

Lecky, Mr., on the sense of duty; on suicide; on the practice of celibacy; his view of the crimes of savages; on

Legs, variation of the length of the, in man; proportions of, in soldiers and sailors; front, atrophied in some

Lemuridae, ears of the; variability of the muscles in the; position and derivation of the; their origin.

Lepidoptera, numerical proportions of the sexes in the; colouring of; ocellated spots of.

Leroy, on the wariness of young foxes in huntingdistricts; on the desertion of their young by swallows.

Leuckart, R., on the vesicula prostatica; on the influence of the age of parents on the sex of offspring.

Lindsay, Dr. W.L., diseases communicated from animals to man; madness in animals; the dog considers his

Linnet, numerical proportion of the sexes in the; crimson forehead and breast of the; courtship of the.

Livingstone, Dr., manner of sitting of gorilla; on the influence of dampness and dryness on the colour of the

skin; on the liability of negroes to tropical fevers after residence in a cold climate; on the spurwinged goose;

on weaverbirds; on an African nightjar; on the battlescars of South African male mammals; on the removal

of the upper incisors by the Batokas; on the perforation of the upper lip by the Makalolo; on the Banyai.

Lloyd, L., on the polygamy of the capercailzie and bustard; on the numerical proportion of the sexes in the

capercailzie and blackcock; on the salmon; on the colours of the seascorpion; on the pugnacity of male

grouse; on the capercailzie and blackcock; on the call of the capercailzie; on assemblages of grouse and

snipes; on the pairing of a shielddrake with a common duck; on the battles of seals; on the elk.

Lubbock, Sir J., on the antiquity of man; on the origin of man; on the mental capacity of savages; on the

origin of implements; on the simplification of languages; on the absence of the idea of God among certain

races of men; on the origin of the belief in spiritual agencies; on superstitions; on the sense of duty; on the

practice of burying the old and sick among the Fijians; on the immorality of savages; on Mr. Wallace's claim

to the origination of the idea of natural selection; on the former barbarism of civilised nations; on

improvements in the arts among savages; on resemblances of the mental characters in different races of men;

on the arts practised by savages; on the power of counting in primeval man; on the prehensile organs of the

male Labidocera Darwinii; on Chloeon; on Smynthurus luteus; finding of new mates by jays; on strife for

women among the North American Indians; on music; on the ornamental practices of savages; on the

estimation of the beard among the AngloSaxons; on artificial deformation of the skull; on "communal

Lungs, enlargement of, in the Quichua and Aymara Indians; a modified swimbladder; different capacity of,

Lyell, Sir C., on the antiquity of man; on the origin of man; on the parallelism of the development of species

and languages; on the extinction of languages; on the Inquisition; on the fossil remains of vertebrata; on the

Macacus, ears of; convoluted body in the extremity of the tail of; variability of the tail in species of; whiskers

Macacus cynomolgus, superciliary ridge of; beard and whiskers of; becoming white with age.

Macalister, Prof., on variations of the palmaris accessorius muscle; on muscular abnormalities in man; on the

Macgillivray, W., on the vocal organs of birds; on the Egyptian goose; on the habits of woodpeckers; on the

habits of the snipe; on the whitethroat; on the moulting of the snipes; on the moulting of the Anatidae; on the

finding of new mates by magpies; on the pairing of a blackbird and thrush; on pied ravens; on the guillemots;

Machetes pugnax, supposed to be polygamous; numerical proportion of the sexes in; pugnacity of the male;

MacLachlan, R., on Apatania muliebris and Boreus hyemalis; on the anal appendages of male insects; on the

pairing of dragonflies; on dragonflies; on dimorphism in Agrion; on the want of pugnacity in male

M'Lennan, Mr., on infanticide; on the origin of the belief in spiritual agencies; on the prevalence of

licentiousness among savages; on the primitive barbarism of civilised nations; on traces of the custom of the

M'Neill, Mr., on the use of the antlers of deer; on the Scotch deerhound; on the long hairs on the throat of the

Magpie, power of speech of; vocal organs of the; nuptial assemblies of; new mates found by; stealing bright

Maillard, M., on the proportion of the sexes in a species of Papilio from Bourbon.

Maine, Sir Henry, on the absorption of one tribe by another; a desire for improvement not general.

Major, Dr. C. Forsyth, on fossil Italian apes; skull of Bos etruscus; tusks of miocene pigs.

Malays, line of separation between the Papuans and the; general beardlessness of the; staining of the teeth

Male animals, struggles of, for the possession of the females; eagerness of, in courtship; generally more

Males and females, comparative numbers of; comparative mortality of, while young.

Mammae, rudimentary, in male mammals; supernumerary, in women; of male human subject.

Mammals, recent and tertiary, comparison of cranial capacity of; nipples of; pursuit of female, by the males;

secondary sexual characters of; weapons of; relative size of the sexes of; parallelism of, with birds in

secondary sexual characters; voices of, used especially during the breeding season.

Man, variability of; erroneously regarded as more domesticated than other animals; migrations of; wide

distribution of; causes of the nakedness of; supposed physical inferiority of; a member of the Catarrhine

group; early progenitors of; transition from ape indefinite; numerical proportions of the sexes in; difference

between the sexes; proportion of sexes amongst the illegitimate; different complexion of male and female

Mandibles, use of the, in Ammophila; large, of Corydalis cornutus; large, of male Lucanus elaphus.

Mantegazza, Prof., on last molar teeth of man; bright colours in male animals; on the ornaments of savages;

on the beardlessness of the New Zealanders; on the exaggeration of natural characters by man.

Maories, mortality of; infanticide and proportion of sexes; distaste for hairiness amongst men.

Marcus Aurelius, on the origin of the moral sense; on the influence of habitual thoughts.

Marriage, restraints upon, among savages; influence of, upon morals; influence of, on mortality; development

Marshall, Dr. W., protuberances on birds' heads; on the moulting of birds; advantage to older birds of

Marshall, Col., interbreeding amongst Todas; infanticide and proportion of sexes with Todas; choice of

Marsupials, development of the nictitating membrane in; uterus of; possession of nipples by; their origin from

Martin, W.C.L., on alarm manifested by an orang at the sight of a turtle; on the hair in Hylobates; on a female

Maudsley, Dr., on the influence of the sense of smell in man; on idiots smelling their food; on Laura

Bridgman; on the development of the vocal organs; moral sense failing in incipient madness; change of

Mental faculties, diversity of, in the same race of men; inheritance of; variation of, in the same species;

Meyer, on a convoluted body at the extremity of the tail in a Macacus and a cat.

Meyer, Prof. L., on development of helix of ear; men's ears more variable than women's; antennae serving as

Mill, J.S., on the origin of the moral sense; on the "greatest happiness principle;" on the difference of the

Mind, difference of, in man and the highest animals; similarity of the, in different races.

Mivart, St. George, on the reduction of organs; on the ears of the lemuroidea; on variability of the muscles in

lemuroidea; on the caudal vertebrae of monkeys; on the classification of the primates; on the orang and on

Mollusca, beautiful colours and shapes of; absence of secondary sexual characters in the.

Monkey, protecting his keeper from a baboon; bonnet; rhesus, sexual difference in colour of the;

Monkeys, liability of, to the same diseases as man; male, recognition of women by; diversity of the mental

faculties in; breaking hard fruits with stones; hands of the; basal caudal vertebrae of, imbedded in the body;

revenge taken by; maternal affection in; variability of the faculty of attention in; American, manifestation of

reason in; using stones and sticks; imitative faculties of; signalcries of; mutual kindnesses of; sentinels

posted by; human characters of; American, direction of the hair on the arms of some; gradation of species of;

beards of; ornamental characters of; analogy of sexual differences of, with those of man; different degrees of

difference in the sexes of; expression of emotions by; generally monogamous habits of; polygamous habits of

Monotremata, development of the nictitating membrane in; lactiferous glands of; connecting mammals with

Monstrosities, analogous, in man and lower animals; caused by arrest of development; correlation of;

Montagu, G., on the habits of the black and red grouse; on the pugnacity of the ruff; on the singing of birds;

Morality, supposed to be founded in selfishness; test of, the general welfare of the community; gradual rise

Morgan, L.H., on the beaver; on the reasoning powers of the beaver; on the forcible capture of wives; on the

Moths, absence of mouth in some males; apterous female; male, prehensile use of the tarsi by; male, attracted

Motmot, inheritance of mutilation of tail feathers; racketshaped feathers in the tail of a.

Muller, Fritz, on astomatous males of Tanais; on the disappearance of spots and stripes in adult mammals; on

the proportions of the sexes in some Crustacea; on secondary sexual characters in various Crustaceans;

musical contest between male Cicadae; mode of holding wings in Castina; on birds shewing a preference for

Muller, Hermann, emergence of bees, from pupa; pollengathering of bees; proportion of sexes in bees;

Muller, Max, on the origin of language; language implies power of general conception; struggle for life

Murie, J., on the reduction of organs; on the ears of the Lemuroidea; on variability of the muscles in the

Lemuroidea; basal caudal vertebrae of Macacus brunneus imbedded in the body; on the manner of sitting in

shorttailed apes; on differences in the Lemuroidea; on the throatpouch of the male bustard; on the mane of

Otaria jubata; on the suborbital pits of Ruminants; on the colours of the sexes in Otaria nigrescens.

Muscles, rudimentary, occurrence of, in man; variability of the; effects of use and disuse upon; animallike

abnormalities of, in man; correlated variation of, in the arm and leg; variability of, in the hands and feet; of

the jaws, influence of, on the physiognomy of the Apes; habitual spasms of, causing modifications of the

facial bones, of the early progenitors of man; greater variability of the, in men than in women.

Music, of birds; discordant, love of savages for; reason of power of perception of notes in animals; power of

distinguishing notes; its connection with primeval speech; different appreciation of, by different peoples;

Muskdeer, canine teeth of male; male, odoriferous organs of the; winter change of the.

Mycetes caraya, polygamous; vocal organs of; beard of; sexual differences of colour in; voice of.

Nageli, on the influence of natural selection on plants; on the gradation of species of plants.

Nathusius, H. von, on the improved breeds of pigs; male domesticated animals more variable than females;

Natural selection, its effects on the early progenitors of man; influence of, on man; limitation of the principle;

influence of, on social animals; Mr. Wallace on the limitation of, by the influence of the mental faculties in

Negroes, Caucasian features in; character of; lice of; fertility of, when crossed with other races; blackness of;

variability of; immunity of, from yellow fever; difference of, from Americans; disfigurements of the; colour

of newborn children of; comparative beardlessness of; readily become musicians; appreciation of beauty of

New Zealand, expectation by the natives of, of their extinction; practice of tattooing in; aversion of natives

Newton, A., on the throatpouch of the male bustard; on the differences between the females of two species

Nightjar, selection of a mate by the female; Australian, sexes of; coloration of the.

Nilsson, Prof., on the resemblance of stone arrowheads from various places; on the development of the

Nose, resemblance of, in man and the apes; piercing and ornamentation of the; very flat, not admired in

Nott and Gliddon, on the features of Rameses II.; on the features of Amunoph III.; on skulls from Brazilian

caves; on the immunity of negroes and mulattoes from yellow fever; on the deformation of the skull among

Occupations, sometimes a cause of diminished stature; effect of, upon the proportions of the body.

Odour, correlation of, with colour of skin; of moths; emitted by snakes in the breeding season; of mammals.

Onitis furcifer, processes of anterior femora of the male, and on the head and thorax of the female.

Onthophagus rangifer, sexual differences of; variations in the horns of the male.

OrangOutan, Bischoff on the agreement of the brain of the, with that of man; adult age of the; ears of the;

vermiform appendage of; hands of the; absence of mastoid processes in the; platforms built by the; alarmed at

the sight of a turtle; using a stick as a lever; using missiles; using the leaves of the Pandanus as a night

covering; direction of the hair on the arms of the; its aberrant characters; supposed evolution of the; voice of

Ornamental characters, equal transmission of, to both sexes, in mammals; of monkeys.

Orthoptera, metamorphosis of; stridulating apparatus of; colours of; rudimentary stridulating organs in

Owen, Prof., on the Corpora Wolffiana; on the great toe in man; on the nictitating membrane and semilunar

fold; on the development of the posterior molars in different races of man; on the length of the caecum in the

Koala; on the coccygeal vertebrae; on rudimentary structures belonging to the reproductive system; on

abnormal conditions of the human uterus; on the number of digits in the Ichthyopterygia; on the canine teeth

in man; on the walking of the chimpanzee and orang; on the mastoid processes in the higher apes; on the

hairiness of elephants in elevated districts; on the caudal vertebrae of monkeys; classification of mammalia;

on the hair in monkeys; on the piscine affinities of the Ichthyosaurians; on polygamy and monogamy among

the antelopes; on the horns of Antilocapra Americana; on the musky odour of crocodiles during the breeding

season; on the scentglands of snakes; on the Dugong, Cachalot, and Ornithorhynchus; on the antlers of the

red deer; on the dentition of the Camelidae; on the horns of the Irish elk; on the voice of the giraffe,

porcupine, and stag; on the laryngeal sac of the gorilla and orang; on the odoriferous glands of mammals; on

the effects of emasculation on the vocal organs of men; on the voice of Hylobates agilis; on American

Paget, on the abnormal development of hairs in man; on the thickness of the skin on the soles of the feet of

Pallas, on the perfection of the senses in the Mongolians; on the want of connexion between climate and the

colour of the skin; on the polygamous habits of Antilope Saiga; on the lighter colour of horses and cattle in

winter in Siberia; on the tusks of the muskdeer; on the odoriferous glands of mammals; on the odoriferous

glands of the muskdeer; on winter changes of colour in mammals; on the ideal of female beauty in North

Papilio, proportion of the sexes in North American species of; sexual differences of colouring in species of;

Papuans, line of separation between the, and the Malays; beards of the; teeth of.

Paradise, Birds of; supposed by Lesson to be polygamous; rattling of their quills by; racketshaped feathers

in; sexual differences in colour of; decomposed feathers in; display of plumage by the male; sexual

Paradisea apoda, barbless feathers in the tail of; plumage of; and P. papuana; divergence of the females of;

Parasites, on man and animals; as evidence of specific identity or distinctness; immunity from, correlated

Parental feeling in earwigs, starfishes, and spiders; affection, partly a result of natural selection.

Park, Mungo, negrowomen teaching their children to love the truth; his treatment by the negrowomen; on

Parrakeet, young of; Australian, variation in the colour of the thighs of a male.

Parrots, change of colour in; imitative faculties of; living in triplets; affection of; colours and nidification of

the; immature plumage of the; colours of; sexual differences of colour in; musical powers of.

Peacock, polygamous; sexual characters of; pugnacity of the; Javan, possessing spurs; rattling of the quills

by; elongated tailcoverts of the; love of display of the; ocellated spots of the; inconvenience of long tail of

Peafowl, preference of females for a particular male; first advances made by the female.

Pelecanus erythrorhynchus, horny crest on the beak of the male, during the breeding season.

Pelican, blind, fed by his companions; young, guided by old birds; pugnacity of the male.

Pelvis, alteration of, to suit the erect attitude of man; differences of the, in the sexes of man.

Pheasant, polygamous; and black grouse, hybrids of; production of hybrids with the common fowl; immature

Pheasant, Argus, display of plumage by the male; ocellated spots of the; gradation of characters in the.

Pheasant, Golden, display of plumage by the male; age of mature plumage in the; sex of young, ascertained

Pheasant, Silver, triumphant male, deposed on account of spoiled plumage; sexual coloration of the.

Pheasant, Tragopan, display of plumage by the male; marking of the sexes of the.

Pheasants, period of acquisition of male characters in the family of the; proportion of sexes in chicks of;

Pigeon, female, deserting a weakened mate; carrier, late development of the wattle in; pouter, late

Pigeons, nestling, fed by the secretion of the crop of both parents; changes of plumage in; transmission of

sexual peculiarities in; Belgian, with blackstreaked males; changing colour after several moultings;

numerical proportion of the sexes in; cooing of; variations in plumage of; display of plumage by male; local

memory of; antipathy of female, to certain males; pairing of; profligate male and female; wingbars and

tailfeathers of; supposititious breed of; pouter and carrier, peculiarities of, predominant in males;

Pigs, origin of the improved breeds of; numerical proportion of the sexes in; stripes of young; tusks of

Plantaineaters, colours and nidification of the; both sexes of, equally brilliant.

Plants, cultivated, more fertile than wild; Nageli, on natural selection in; male flowers of, mature before the

Plumage, changes of, inheritance of, by fowls; tendency to analogous variation in; display of, by male birds;

changes of, in relation to season; immature, of birds; colour of, in relation to protection.

Polygamy, influence of, upon sexual selection; superinduced by domestication; supposed increase of female

Polynesians, wide geographical range of; difference of stature among the; crosses of; variability of;

Polyplectron, number of spurs in; display of plumage by the male; gradation of characters in; female of.

Pouchet, G., the relation of instinct to intelligence; on the instincts of ants; on the caves of AbouSimbel; on

Prichard, on the difference of stature among the Polynesians; on the connection between the breadth of the

skull in the Mongolians and the perfection of their senses; on the capacity of British skulls of different ages;

on the flattened heads of the Colombian savages; on Siamese notions of beauty; on the beardlessness of the

Siamese; on the deformation of the head among American tribes and the natives of Arakhan.

PrunerBey, on the occurrence of the supracondyloid foramen in the humerus of man; on the colour of

Ptarmigan, monogamous; summer and winter plumage of the; nuptial assemblages of; triple moult of the;

Pycnonotus haemorrhous, pugnacity of the male; display of undertail coverts by the male.

Quadrumana, hands of; differences between man and the; sexual differences of colour in; ornamental

characters of; analogy of sexual differences of, with those of man; fighting of males for the females;

Quatrefages, A. de, on the occurrence of a rudimentary tail in man; on variability; on the moral sense as a

distinction between man and animals; civilised men stronger than savages; on the fertility of Australian

women with white men; on the Paulistas of Brazil; on the evolution of the breeds of cattle; on the Jews; on

the liability of negroes to tropical fevers after residence in a cold climate; on the difference between field

and houseslaves; on the influence of climate on colour; colours of annelids; on the Ainos; on the women of

Quichua Indians; local variation of colour in the; no grey hair among the; hairlessness of the; long hair of the.

Rabbits, domestic, elongation of the skull in; modification of the skull in, by the lopping of the ear;

Races, distinctive characters of; or species of man; crossed, fertility or sterility of; of man, variability of the;

of man, resemblance of, in mental characters; formation of; of man, extinction of; effects of the crossing of;

of man, formation of the; of man, children of the; beardless, aversion of, to hairs on the face.

Ramsay, Mr., on the Australian muskduck; on the regentbird; on the incubation of Menura superba.

Rat, common, general dispersion of, a consequence of superior cunning; supplantation of the native in New

Zealand, by the European rat; common, said to be polygamous; numerical proportion of the sexes in.

Raven, vocal organs of the; stealing bright objects; pied, of the Feroe Islands.

Reade, Winwood, suicide among savages in Africa; mulattoes not prolific; effect of castration of horned

sheep; on the Guinea sheep; on the occurrence of a mane in an African ram; on singing of negroes; on the

negroes' appreciation of the beauty of their women; on the admiration of negroes for a black skin; on the idea

Reeks, H., retention of horns by breeding deer; cow rejected by a bull; destruction of piebald rabbits by cats.

Reindeer, horns of the; battles of; horns of the female; antlers of, with numerous points; winter change of the;

Rengger, on the diseases of Cebus Azarae; on the diversity of the mental faculties of monkeys; on the

Payaguas Indians; on the inferiority of Europeans to savages in their senses; revenge taken by monkeys; on

maternal affection in a Cebus; on the reasoning powers of American monkeys; on the use of stones by

monkeys for cracking hard nuts; on the sounds uttered by Cebus Azarae; on the signalcries of monkeys; on

the polygamous habits of Mycetes caraya; on the voice of the howling monkeys; on the odour of Cervus

campestris; on the beards of Mycetes caraya and Pithecia Satanas; on the colours of Felis mitis; on the

colours of Cervus paludosus; on sexual differences of colour in Mycetes; on the colour of the infant

Guaranys; on the early maturity of the female of Cebus Azarae; on the beards of the Guaranys; on the

Reproduction, unity of phenomena of, throughout the mammalia; period of, in birds.

Rhinoceros, nakedness of; horns of; horns of, used defensively; attacking white or grey horses.

Richardson, Sir J., on the pairing of Tetrao umbellus; on Tetrao urophasianus; on the drumming of grouse; on

the dances of Tetrao phasianellus; on assemblages of grouse; on the battles of male deer; on the reindeer; on

the horns of the muskox; on antlers of the reindeer with numerous points; on the moose; on the Scotch

Riley, Mr., on mimicry in butterflies; bird's disgust at taste of certain caterpillars.

Robertson, Mr., remarks on the development of the horns in the roebuck and red deer.

Robin, pugnacity of the male; autumn song of the; female singing of the; attacking other birds with red in

Robinet, on the difference of size of the male and female cocoons of the silkmoth.

Rodents, uterus in the; absence of secondary sexual characters in; sexual differences in the colours of.

Rohfs, Dr., Caucasian features in negro; fertility of mixed races in Sahara; colours of birds in Sahara; ideas of

Rolle, F., on the origin of man; on a change in German families settled in Georgia.

Rossler, Dr., on the resemblance of the lower surface of butterflies to the bark of trees.

Ruff, supposed to be polygamous; proportion of the sexes in the; pugnacity of the; double moult in; duration

Ruminants, male, disappearance of canine teeth in; generally polygamous; suborbital pits of; sexual

Rutimeyer, Prof., on the physiognomy of the apes; on tusks of miocene boar; on the sexual differences of

Sachs, Prof., on the behaviour of the male and female elements in fertilisation.

Salmo eriox, and Salmo umbla, colouring of the male, during the breeding season.

Salmon, leaping out of fresh water; male, ready to breed before the female; proportion of the sexes in; male,

pugnacity of the; male, characters of, during the breeding season; spawning of the; breeding of immature

Salvin, O., inheritance of mutilated feathers; on the Hummingbirds; on the numerical proportion of the

sexes in Hummingbirds; on Chamaepetes and Penelope; on Selasphorus platycercus; Pipra deliciosa; on

Sandwich Islands, variation in the skulls of the natives of the; decrease of native population; population of;

Savage, Dr., on the fighting of the male gorillas; on the habits of the gorilla.

Savages, uniformity of, exaggerated; longsighted; rate of increase among, usually small; retention of the

prehensile power of the feet by; imitative faculties of; causes of low morality of; tribes of, supplanting one

another; improvements in the arts among; arts of; fondness of, for rough music; on longenduring fashions

Schaaffhausen, Prof., on the development of the posterior molars in different races of man; on the jaw from

La Naulette; on the correlation between muscularity and prominent supraorbital ridges; on the mastoid

processes of man; on modifications of the cranial bones; on human sacrifices; on the probable speedy

extermination of the anthropomorphous apes; on the ancient inhabitants of Europe; on the effects of use and

disuse of parts; on the superciliary ridge in man; on the absence of racedifferences in the infant skull in

Schomburgk, Sir R., on the pugnacity of the male muskduck of Guiana; on the courtship of Rupicola

Sclater, P.L., on modified secondary wingfeathers in the males of Pipra; on elongated feathers in nightjars;

on the species of Chasmorhynchus; on the plumage of Pelecanus onocrotalus; on the plantaineaters; on the

sexes and young of Tadorna variegata; on the colours of Lemur macaco; on the stripes in asses.

Scudder, S.H., imitation of the stridulation of the Orthoptera; on the stridulation of the Acridiidae; on a

Seals, their sentinels generally females; evidence furnished by, on classification; polygamous habits of;

battles of male; canine teeth of male; sexual differences; pairing of; sexual peculiarities of; in the coloration

Season, changes of colour in birds, in accordance with the; changes of plumage of birds in relation to.

Secondary sexual characters; relations of polygamy to; transmitted through both sexes; gradation of, in birds.

Seemann, Dr., on the different appreciation of music by different peoples; on the effects of music.

Selection, sexual, explanation of; influence of, on the colouring of Lepidoptera.

Sexes, relative proportions of, in man; proportions of, sometimes influenced by selection; probable relation of

Sexual characters, secondary; relations of polygamy to; transmitted through both sexes; gradation of, in birds.

Sexual selection, explanation of; influence of, on the colouring of Lepidoptera; objections to; action of, in

Sharpe, R.B., on Tanysiptera sylvia; on Ceryle; on the young male of Dacelo Gaudichaudi.

Sheep, dangersignals of; sexual differences in the horns of; horns of; domestic, sexual differences of, late

developed; numerical proportion of the sexes in; inheritance of horns by one sex; effect of castration; mode of

Shells, difference in form of, in male and female Gasteropoda; beautiful colours and shapes of.

Siamese, general beardlessness of the; notions of beauty of the; hairy family of.

Sidgwick, H., on morality in hypothetical bee community; our actions not entirely directed by pain and

Siebold, C.T., von, on the proportion of sexes in the Apus; on the auditory apparatus of the stridulent

Silkmoth, proportion of the sexes in; Ailanthus, Prof. Canestrini, on the destruction of its larvae by wasps;

Skull, variation of, in man; cubic contents of, no absolute test of intellect; Neanderthal, capacity of the;

causes of modification of the; difference of, in form and capacity, in different races of men; variability of the

shape of the; differences of, in the sexes in man; artificial modification of the shape of.

Smith, Sir A., on the recognition of women by male Cynocephali; on revenge by a baboon; on an instance of

memory in a baboon; on the retention of their colour by the Dutch in South Africa; on the polygamy of the

South African antelopes; on the polygamy of the lion; on the proportion of the sexes in Kobus

ellipsiprymnus; on Bucephalus capensis; on South African lizards; on fighting gnus; on the horns of

rhinoceroses; on the fighting of lions; on the colours of the Cape Eland; on the colours of the gnu; on

Smith, F., on the Cynipidae and Tenthredinidae; on the relative size of the sexes of Aculeate Hymenoptera;

on the difference between the sexes of ants and bees; on the stridulation of Trox sabulosus; on the stridulation

Sociability, the sense of duty connected with; impulse to, in animals; manifestations of, in man; instinct of, in

Sociality, probable, of primeval men; influence of, on the development of the intellectual faculties; origin of,

Song, of male birds appreciated by their females; want of, in brilliant plumaged birds; of birds.

Sounds, admired alike by man and animals; produced by fishes; produced by male frogs and toads;

Sparrow, pugnacity of the male; acquisition of the Linnet's song by a; coloration of the; immature plumage of

Species, causes of the advancement of; distinctive characters of; or races of man; sterility and fertility of,

when crossed; supposed, of man; gradation of; difficulty of defining; representative, of birds; of birds,

Speech, connection between the brain and the faculty of; connection of intonation with music.

Spencer, Herbert, on the influence of food on the size of the jaws; on the dawn of intelligence; on the origin

of the belief in spiritual agencies; on the origin of the moral sense; on music.

Spiders, parental feeling in; male, more active than female; proportion of the sexes in; secondary sexual

Sproat, Mr., on the extinction of savages in Vancouver Island; on the eradication of facial hair by the natives

of Vancouver Island; on the eradication of the beard by the Indians of Vancouver Island.

Spurs, occurrence of, in female fowls; development of, in various species of Phasianidae; of Gallinaceous

Squirrels, battles of male; African, sexual differences in the colouring of; black.

Stag, long hairs of the throat of; horns of the; battles of; horns of the, with numerous branches; bellowing of

Stagbeetle, numerical proportion of sexes of; use of jaws; large size of male; weapons of the male.

Stainton, H.T., on the numerical proportion of the sexes in the smaller moths; habits of Elachista rufocinerea;

on the coloration of moths; on the rejection of Spilosoma menthastri by turkeys; on the sexes of Agrotis

Stark, Dr., on the deathrate in towns and rural districts; on the influence of marriage on mortality; on the

Stephen, Mr. L., on the difference in the minds of men and animals; on general concepts in animals;

Sterility, general, of sole daughters; when crossed, a distinctive character of species; under changed

Stickleback, polygamous; male, courtship of the; male, brilliant colouring of, during the breeding season;

Stridulation, by males of Theridion; of Hemiptera; of the Orthoptera and Homoptera discussed; of beetles.

Stripes, retained throughout groups of birds; disappearance of, in adult mammals.

Struthers, Dr., on the occurrence of the supracondyloid foramen in the humerus of man.

Suicide, formerly not regarded as a crime; rarely practised among the lowest savages.

Supernumerary digits, more frequent in men than in women; inheritance of; early development of.

Swan, black, wild, trachea of the; white, young of; red beak of the; blacknecked.

Swinhoe, R., on the common rat in Formosa and China; behaviour of lizards when caught; on the sounds

produced by the male hoopoe; on Dicrurus macrocercus and the spoonbill; on the young of Ardeola; on the

habits of Turnix; on the habits of Rhynchaea bengalensis; on Orioles breeding in immature plumage.

Tail, rudimentary, occurrence of, in man; convoluted body in the extremity of the; absence of, in man and the

higher apes; variability of, in species of Macacus and in baboons; presence of, in the early progenitors of

man; length of, in pheasants; difference of length of the, in the two sexes of birds.

Tanais, absence of mouth in the males of some species of; relations of the sexes in; dimorphic males of a

Teeth, rudimentary incisor, in Ruminants; posterior molar, in man; wisdom; diversity of; canine, in the early

progenitors of man; canine, of male mammals; in man, reduced by correlation; staining of the; front, knocked

Tegetmeier, Mr., on the transmission of colours in pigeons by one sex alone; numerical proportion of male

and female births in dogs; on the abundance of male pigeons; on the wattles of gamecocks; on the courtship

Tench, proportions of the sexes in the; brightness of male, during breeding season.

Tennent, Sir J.E., on the tusks of the Ceylon Elephant; on the frequent absence of beard in the natives of

Tenthredinidae, proportions of the sexes in; fighting habits of male; difference of the sexes in.

Thomisus citreus, and Thomisus floricolens, difference of colour in the sexes of.

Thompson, W., on the colouring of the male char during the breeding season; on the pugnacity of the males

of Gallinula chloropus; on the finding of new mates by magpies; on the finding of new mates by Peregrine

Thury, M., on the numerical proportion of male and female births among the Jews.

Todas, infanticide and proportion of sexes; practice polyandry; choice of husbands amongst.

Trachea, convoluted and imbedded in the sternum, in some birds; structure of the, in Rhynchaea.

Tragopan, swelling of the wattles of the male, during courtship; display of plumage by the male; marking of

Trimen, R., on the proportion of the sexes in South African butterflies; on the attraction of males by the

female Lasiocampa quercus; on Pneumora; on difference of colour in the sexes of beetles; on moths

brilliantly coloured beneath; on mimicry in butterflies; on Gynanisa Isis, and on the ocellated spots of

Tristram, H.B., on unhealthy districts in North Africa; on the habits of the chaffinch in Palestine; on the birds

Truth, not rare between members of the same tribe; more highly appreciated by certain tribes.

Turkey, wild, pugnacity of young male; wild, notes of the; swelling of the wattles of the male; variety of,

with a topknot; recognition of a dog by a; male, wild, acceptable to domesticated females; wild, first

Turkeycock, scraping of the wings of, upon the ground; wild, display of plumage by; fighting habits of.

Turner, Prof. W., on muscular fasciculi in man referable to the panniculus carnosus; on the occurrence of the

supracondyloid foramen in the human humerus; on muscles attached to the coccyx in man; on the filum

terminale in man; on the variability of the muscles; on abnormal conditions of the human uterus; on the

development of the mammary glands; on male fishes hatching ova in their mouths; on the external

perpendicular fissure of the brain; on the bridging convolutions in the brain of a chimpanzee.

Tylor, E.B., on emotional cries, gestures, etc., of man; on the origin of the belief in spiritual agencies;

remorse for violation of tribal usage in marrying; on the primitive barbarism of civilised nations; on the

origin of counting; inventions of savages; on resemblances, of the mental characters in different races of man.

United States, rate of increase in; influence of natural selection on the progress of; change undergone by

Uterus, reversion in the; more or less divided, in the human subject; double, in the early progenitors of man.

Vancouver Island, Mr. Sproat on the savages of; natives of, eradication of facial hair by the.

Variability, causes of; in man, analogous to that in the lower animals; of the races of man; greater in men than

in women; period of, relation of the, to sexual selection; of birds; of secondary sexual characters in man.

Variation, laws of; correlated; in man; analogous; analogous, in plumage of birds.

Verreaux, M., on the attraction of numerous males by the female of an Australian Bombyx.

Vertebrae, caudal, number of in macaques and baboons; of monkeys, partly imbedded in the body.

Vertebrata, common origin of the; most ancient progenitors of; origin of the voice in airbreathing.

Vocal organs of man; of birds; of frogs; of the Insessores; difference of, in the sexes of birds; primarily used

Vogt, Karl, on the origin of species; on the origin of man; on the semilunar fold in man; on microcephalous

idiots; on the imitative faculties of microcephalous idiots; on skulls from Brazilian caves; on the evolution of

the races of man; on the formation of the skull in women; on the Ainos and negroes; on the increased cranial

difference of the sexes in man with race development; on the obliquity of the eye in the Chinese and

Voice in mammals; in monkeys and man; in man; origin of, in airbreathing vertebrates.

Vulpian, Prof., on the resemblance between the brains of man and the higher apes.

Wagner, R., on the occurrence of the diastema in a Kaffir skull; on the bronchi of the black stork.

Waitz, Prof., on the number of species of man; on the liability of negroes to tropical fevers after residence in

a cold climate; on the colour of Australian infants; on the beardlessness of negroes; on the fondness of

mankind for ornaments; on negro ideas of female beauty; on Javan and Cochin Chinese ideas of beauty.

Wallace, Dr. A., on the prehensile use of the tarsi in male moths; on the rearing of the Ailanthus silkmoth; on

breeding Lepidoptera; proportion of sexes of Bombyx cynthia, B. yamamai, and B. Pernyi reared by; on the

Wallace, A.R., on the origin of man; on the power of imitation in man; on the use of missiles by the orang; on

the varying appreciation of truth among different tribes; on the limits of natural selection in man; on the

occurrence of remorse among savages; on the effects of natural selection on civilised nations; on the use of

the convergence of the hair at the elbow in the orang; on the contrast in the characters of the Malays and

Papuans; on the line of separation between the Papuans and Malays; on the birds of paradise; on the sexes of

Ornithoptera Croesus; on protective resemblances; on the relative sizes of the sexes of insects; on

Elaphomyia; on the pugnacity of the males of Leptorhynchus angustatus; on sounds produced by Euchirus

longimanus; on the colours of Diadema; on Kallima; on the protective colouring of moths; on bright

coloration as protective in butterflies; on variability in the Papilionidae; on male and female butterflies,

inhabiting different stations; on the protective nature of the dull colouring of female butterflies; on mimicry

in butterflies; on the bright colours of caterpillars; on brightlycoloured fishes frequenting reefs; on the coral

snakes; on Paradisea apoda; on the display of plumage by male birds of paradise; on assemblies of birds of

paradise; on the instability of the ocellated spots in Hipparchia Janira; on sexually limited inheritance; on the

sexual coloration of birds; on the relation between the colours and nidification of birds; on the coloration of

the Cotingidae; on the females of Paradisea apoda and papuana; on the incubation of the cassowary; on

protective coloration in birds; on the Babirusa; on the markings of the tiger; on the beards of the Papuans; on

Walrus, development of the nictitating membrane in the; tusks of the; use of the tusks by the.

Walsh, B.D., on the proportion of the sexes in Papilio Turnus; on the Cynipidae and Cecidomyidae; on the

jaws of Ammophila; on Corydalis cornutus; on the prehensile organs of male insects; on the antennae of

Penthe; on the caudal appendages of dragonflies; on Platyphyllum concavum; on the sexes of the

Ephemeridae; on the difference of colour in the sexes of Spectrum femoratum; on sexes of dragonflies; on

the difference of the sexes in the Ichneumonidae; on the sexes of Orsodacna atra; on the variation of the horns

Wapiti, battles of; traces of horns in the female; attacking a man; crest of the male; sexual difference in the

Warington, R., on the habits of the stickleback; on the brilliant colours of the male stickleback during the

Waterhouse, C.O., on blind beetles; on difference of colour in the sexes of beetles.

Waterton, C., on the Bellbird; on the pairing of a Canada goose with a Bernicle gander; on hares fighting.

Weir, Harrison, on the numerical proportion of the sexes in pigs and rabbits; on the sexes of young pigeons;

on the songs of birds; on pigeons; on the dislike of blue pigeons to other coloured varieties; on the desertion

Weir, J. Jenner, on the nightingale and blackcap; on the relative sexual maturity of male birds; on female

pigeons deserting a feeble mate; on three starlings frequenting the same nest; on the proportion of the sexes in

Machetes pugnax and other birds; on the coloration of the Triphaenae; on the rejection of certain caterpillars

by birds; on sexual differences of the beak in the goldfinch; on a piping bullfinch; on the object of the

nightingale's song; on songbirds; on the pugnacity of male fineplumaged birds; on the courtship of birds;

on the finding of new mates by Peregrine falcons and Kestrels; on the bullfinch and starling; on the cause of

birds remaining unpaired; on starlings and parrots living in triplets; on recognition of colour by birds; on

hybrid birds; on the selection of a greenfinch by a female canary; on a case of rivalry of female bullfinches;

Weisbach, Dr., measurement of men of different races; on the greater variability of men than of women; on

Welcker, M., on brachycephaly and dolichocephaly; on sexual differences in the skull in man.

Westring, on the stridulation of males of Theridion; on the stridulation of Reduvius personatus; on the

stridulation of beetles; on the stridulation of Omaloplia brunnea; on the stridulating organs of the Coleoptera;

Westropp, H.M., on reason in a bear; on the prevalence of certain forms of ornamentation.

Westwood, J.O., on the classification of the Hymenoptera; on the Culicidae and Tabanidae; on a

Hymenopterous parasite with a sedentary male; on the proportions of the sexes in Lucanus cervus and

Siagonium; on the absence of ocelli in female Mutillidae; on the jaws of Ammophila; on the copulation of

insects of distinct species; on the male of Crabro cribrarius; on the pugnacity of the male Tipulae; on the

stridulation of Pirates stridulus; on the Cicadae; on the stridulating organs of the cricket; on Ephippiger

vitium; on Pneumora; on the pugnacity of the Mantides; on Platyblemnus; on difference in the sexes of the

Agrionidae; on the pugnacity of the males of a species of Tenthredinae; on the pugnacity of the male

stagbeetle; on Bledius taurus and Siagonium; on lamellicorn beetles; on the coloration of Lithosia.

Whately, Arch., language not peculiar to man; on the primitive civilisation of man.

White, Gilbert, on the proportion of the sexes in the partridge; on the housecricket; on the object of the song

of birds; on the finding of new mates by white owls; on spring coveys of male partridges.

Whiteness, a sexual ornament in some birds; of mammals inhabiting snowy countries.

Whitney, Prof., on the development of language; language not indispensable for thought.

Widowbird, polygamous; breeding plumage of the male; female, rejecting the unadorned male.

Wilckens, Dr., on the modification of domestic animals in mountainous regions; on a numerical relation

Wilder, Dr. Burt, on the greater frequency of supernumerary digits in men than in women.

Wilson, Dr., on the conical heads of the natives of NorthWestern Africa; on the Fijians; on the persistence

Wings, differences of, in the two sexes of butterflies and Hymenoptera; play of, in the courtship of birds.

Wollaston, T.V., on Eurygnathus; on musical Curculionidae; on the stridulation of Acalles.

Women, distinguished from men by male monkeys; preponderance of, in numbers; selection of, for beauty;

effects of selection of, in accordance with different standards of beauty; practice of capturing; early betrothals

Wood, J., on muscular variations in man; on the greater variability of the muscles in men than in women.

Wood, T.W., on the colouring of the orangetip butterfly; on the habits of the Saturniidae; quarrels of

chamaeleons; on the habits of Menura Alberti; on Tetrao cupido; on the display of plumage by male

pheasants; on the ocellated spots of the Argus pheasant; on fighting of Menura superba; on the habits of the

Wright, Chauncey, great brainpower requisite for language; on correlative acquisition; on the enlargement

Wright, Mr., on the Scotch deerhound; on sexual preference in dogs; on the rejection of a horse by a mare.

Wyman, Prof., on the prolongation of the coccyx in the human embryo; on the condition of the great toe in

the human embryo; on the occurrence of the supracondyloid foramen in the humerus of man; on variation in

the skulls of the natives of the Sandwich Islands; on the hatching of the eggs in the mouths and branchial

Yarrel, W., on the habits of the Cyprinidae; on Raia clavata; on the characters of the male salmon during the

breeding season; on the characters of the rays; on the gemmeous dragonet; on colours of salmon; on the

spawning of the salmon; on the incubation of the Lophobranchii; on rivalry in songbirds; on the trachea of

Zouteveen, Dr., polydactylism; proportion of sexes at Cape of Good Hope; spiders attracted by music; on