ffi POLL; REOi LON D.g /Cawy^ I a KING’S College LONDON Library •'fl^ d£0(E^ ()l AK^i, 0/iJ ma lico^iO Digitized by the Internet Archive in 2015 https://archive.org/details/b21303137 ■» if THE DESCENT OF MAN, AND SELECTION IN EELATION TO SEX. THE DESCENT OF MAN AND SELECTION m EELATIOX TO SEX. By CHAELES DAEWIN, M.A, E.E.S. SECOND EDITION, REVISED AND AUGMENTED. FIFTEENTH .THOUSAND. Illiistraticns. LONDON: JOHN MUKKAZ, ALBEMAELE STEEET. 1882. 7/w riglii qf Trond'^Xation is reserved. KC5M0 Qwu‘:>-OR im BY THE SAME AUTHOR- A NATURALIST’S VOYAGE ROUND THE WORLD; or, A JoDKNAr- OP KksEAUCIIE.S into tub XaTORAL Ul.STOltP AND Gl'X)I-OCy OB THK CouNTRiKS visited during the Voyage of ‘Beagle/ under the cctu- niand of Captain FrrzRoT, Fijttenlh Thousand. 9s. ]SIcj:uav. ORIGIN OP SPECIES BY MEANS OP NATURAL SELEC- TION ; or, The PRESEiivATroH of Tavoehed Kaces ik the Steucgle rou Life. Tuenty-second Thousand. Is. 6d. Mukilly. VARIOUS CONTRIVANCES BY WHICH BRITISH AND FOREIGN ORCHIDS ARE FERTILIZED BY INSECTS. TUird TItotuatrl. With Woodcuts. 9s. JloUBAy. VARIATION OP ANIMALS AND PLANTS UNDER DO- MESriCATION. Al’ith IlluBtrutions. Fifth Thousand. 2 vols. I8s. JIUHEAV. DESCENT OP MAN, AND SELECTION IN RELATION TO SEX. AVith lllustraiioiig. Fifteenth Tkunsand. 9s. JIueuav. EXPRESSION OP THE EMOTIONS IN MAN AND ANI- MALS. With Illustrations. Finlh 'Jlwusand, I2s. Mcekav. INSECTIVOROUS PLANTS. With Illustratious. Third Thou- sand, 14s. Alb'EE.tV. MOVEMENTS AND HABITS OF CLIMBING PLANTS. With illustrations. Third Thousand. 6s. Moeu.vv. EFFECTS OP CROSS AND SELF-FERTILIZATION IN THE VEGETABLE KiNGDOJI. Second Thousand. 12s. MuEU.tv. DIFFERENT FORMS OP FLOWERS ON PLANTS OF THE Same species, second Thousand. 10s. Ud. Mceuav. LIFE OP ERASMUS DARWIN. By Erxest Kradse. With Preliminary Notice. 7s. 6d. Morrav. POWER OF MOVEMENT IN PLANTS. With Woodcuts. Second Thousand. 15s. Mokr-ci . FORMATION OF VEGETABLE MOULD THROUGH THi: ACTION OJJ' AVORMS, with Observatioui on Uitir Habits, tiixth Thousand. 9s. Murr.vv. ON THE STRUCTURE AND DISTRIBUTION OF CORAL REEFS. Second Edition, i-evUed. smith, Eluer, A Co. GEOLOGICAL OBSERVATIONS ON THE VOLCANIC ISLANDS AND PARTS OF SOUTH AMERICA, visited during the Voyage of H.M.S. ‘ Beagle.’ Second Edition. Smith, ELDBit Jt Co. A MONOGRAPH OF THE CIRRIPEDIA. With numerous Illustrations. 2 vols. Rat Societi-. J Lvitn wiciti;. A MONOGRAPH OP THE FOSSIL LEPADIDiE, OR PEOUNCULATED CIRRIPEDS OF GREAT BRITAIN. Palieostograpuical SOCIETT. A MONOGRAPH OF THE FOSSIL BALANIDHi: AND VERRUClDAi OF GREAT BRITAIN. PAi-Jto.N’TOQBAPUiCAL SociEiv. FACTS AND ARGUMENTS FOR DARWIN. By Fisrrz IVIOllek. From the German, with Additions by the Author. Trauslatcd by W. S. UalLaVS, F.L.S, With Illustratious. 6s. aMujikay. LONDON: PltlNTKD BY WILLTAM CLOWES AND SONS, LIMITKD, STAMFOUD STUEI-.r AND CUAUINO CUOSS, FEEFACE TO THE SECOND EDITION. Fcuing the successive reprints of the fii’st edition of this worlr, 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 thi-ough which the boob has passed, and have taken advantage of all the criticisms which seem to me sound. I am also gi’eatly indebted to a large number of correspondents for the communication of a sm-prising 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 con’ections, I will append a list. Some new illustrations have been introduced, and four of the old di’awings have been replaced by better ones, done fi'om 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 difierences between the brains of man and the higher apes. I have been particularly glad to give these obser- vations, because dui-ing the last few years several memoirs on tho subject have appeared on the Continent, and their importance has been, in some cases, gi-eatly exaggerated by popular writers. I may take this opportunity of remarkiag 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 bo attributed to the inherited cSccts of use and disuse, with respect both to the body and mind. I also attributed some amount of modification to tho direct and prolonged action of changed conditions of life. Some allowance, too, must be made for occasional reversions of VI Preface to the Second Edition. 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 accu- mulated by selection, other parte wilt be modified. Again, it has been said by several critics, that when I found tliat 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 ol 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 oi many of the half-favouiuble 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 lU’obable, or almost certain, that several of my con- clusions will hereafter be found erroneous ; this can hardly fail to be the case in the first ti’eatment 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 favourably received by several capable judges. Powu, Beckknham, Kent, Septcrv.ber 1874. TABLE OF THE PEINCIPAL ADDITIONS AND COEEECTIONS TO THJ] PEESENT EDITION. First Edition. Voi,. I. Present Edition. Page Page 22 15-17 26 19 27, note. 20, note. 29 23 32, note. 24, note, 40 70 42 44 72-3 47 75 .50 80 53 83 58 88-9 64 92 78 104 79 104 81 105-6 90, note. G12-113,l \ note. / 91 114 !)4 117, note. 07 120, note. 112 28 122 35-6 124, note. 39, note. 125, note. 36-8, note. 128-9 41-2 146 55, note. I Discussion on the rudimentary points in the \ human ear revised. Cases of men born with hairy bodies. Mantegazza on the last molar tooth in man. The rudiments of a tail in man. (Bianconi on homologous structures, as ex- I irlained by adaptation on mechauical j principles. Intelligence in a baboon. Sense of humour in dogs. fFm’ther facts on imitation in man and \ animals. Eeasoning power in the lower animals. Acquisition of experience by animals. Power of abstraction in animals. tPower of forming concepts in relation to \ language. fPleasure from certain sounds, colours, and \ forms. Fidelity in the elephant. Gallon on gregariousness of cattle. Parental affection. Persistence of enmity and hatred. {Nature and strength of shame, regret, and remorse. Suicide amongst savages. The motives of conduct. Selection, as applied to pritneval man. Eesemblanccs between idiots and animals. Division of the malar bone. Supernumerary inammoo and digits. tFurther cases of muscles proper to animals \ appearing in man. I Broca: average capacity of skull diminished < by the preservation of tho inferior members I of society. Table of tJie Principal Additions and viii I'irst 1 Kdition. I Voi.. I. Present iidition. Page (•age 119 57 150 58-9 109 134-5 ISO 143 193 151 208. note. IGl, note 209 163 239 188-190 245 195-G . 2.50 199-20C 2m 209-210 275-G 224-5 200 235 301 243-4 314 254. 315 255-0 327 204 33S 272 339 273 345 277 349 280 350 281 351 . 282 :^51: 284-5 359 288, note. 3G6 292-3 387 308 397 315 401 319 412 324-5 .1, 326 I Belt on advantages to man from his hair- \ lessness. ( Disappearance of the tail in man and certain \ monkeys. (Injurious forms of selection in civilised \ nations. jindolence of man, when free from a .struggle 1 for existence. (Gorilla protecting himself from rain with his t hands. Hermaphroditism in fish. Rudimentary raammse in male mammals. ( Changed conditions lessen fertility and cause \ ill-health amongst savages. (Darkness of skin a protection against the \ sun. (Note by Professor Huxley on the develop- t ment of the brain in man and apes. (Special organs of male parasitic W'orms for \ holding the female. (Greater variability of male than female; < direct action of the envfronment in causing I differences between the sexes. i Period of development of protuberances on birds’ heads determines their tians- mission to one or both sexes. Causes of excess of male births. Pi-oportion of the sexes in the bee tamilj'. JExcess of males perhaps sometimes deter- t mined by selection. Bright colours of lowdy organised animals. Sexual selection amongst spiders. Cause of smallness of male spiders. Use of phosphorescence of the glow-wonn. The humming noises of flies. Use of bright colom's to Hemiptera (bugs). Musical apparatus of Homoptera. ("Development of stridulating apparatus in \ Orthoptera. (Hermann Miillcr on sexual difi’erences of \ bees. Sounds produced by moths. Display of beauty by butterflies. /Female butterflies, taking the more active \ part in courtship, brighter than their males. ( Further cases of mimicry in butterflies and \ moths. ' /Cau.se of bright and diversified colours of \ cateipillars. Corrections to the Present Edition. IX First Kdition. VOL. 11. Present Kdition. race Page 2 331 14 341 23 347 2G 349 30 352 32 353- 80 357 72 383 01 398 lOS 411 118 417 120 419 124 423 147-150 438-441 152 443 157 446 232 495-6 247 505 248 506 256 513-514 260 516 266 521 286 534 299 542-3 316 556 337 572 356 586 359 ei seq. 588 et seq. 373 598-9 380 603 Bnish-like scales of male Mallotus. /Further facts on courtship of tishes, and the \ spawning of Macropus. Dufosse on the sounds made by fishes. Belt on a frog protected by bright colouring. Further facts on mental powers of snakes. Sounds produced by snakes ; the rattlesnake. Combats of Chameleons. Marshall on protuberances on birds’ heads. (Further facts on display by the Argus \ pheasant. Attachment between paired birds. Female pigeon rejecting certain males. /Albino birds not finding partners, in a state I of nature. Direct action of climate on birds’ colours. /Further tacts on the ocelli in the Argus \ pheasant. Display by humming-birds in courtshiiJ. /Cases with pigeons of colour transmitted to \ one sex alone. {Taste for the beautiful permament enough to allow of sexual selection with the lower animals. /Horns of sheep originally a masculine \ character. Castration affecting horns of animals. Prong-homed variety of Cervus virgmianus. /Relative sizes of male and female whales and \ seals. Absence of tusks in male miocone pigs. Dobson on sexual differences of bats. Reeks on advantage from peculiar colouring. /Difference of complexion in men and women \ of an African tribe. Speech subsequent to singing. /Schopenhauer on importance of courtship to \ mankind. /Revision of discussion on communal marriages \ and promiscuity. /Power of choice of woman in marriage, \ amongst savages. /Long-continued habit of plucking out hairs \ may produce an inherited eliect. ^ % y\ -»-. .. - , ' • /»i-... i »Vfhf ‘»hlW l» K»’*/«J?W*jJli»if ■« ; l%4 *4|»» X'f t<^.f‘ ►» • ■" -■ ,.V, • ’•• I i., - - . '(t .-TwiB »^*‘'**l**AH'‘-'ij»^'''l/' t J(l(44«'% I?-' fl*V n^/.. W»Tl»l i~5» *•■ *w» Miiljr . *• .'iift'l .■ .-^la a r+ y / #4iw' •*» •fW im*- .1 i(^ aNir*** 1 4 1 iM if^fi.i li» ^flSyuto^ •»itt * ^ Vlf*^ *•••*» ■ 4 4l<«^ * 'k, «4ku»' “t e '' ■ fl>Ni t— • , ^ «»4Mlt«(ll'^ »i^w**-*> <*.«!»! »«4 m'^ 3' .lA' •f'.> L ‘'•H. k r»>'* <• <<(♦* t nr. "• «'■' > ' * ■»T - -^£ ■ . 1 ^ ■•■p*.',-»r’*“' ▼ .»v -. — .. V - if " - 4- ‘ -^* ■ B .f ■>« A--fv*t* ■•^. • ■ W" Vi '•»*«»•• -?4» ’»••■»»«“*<•• *l‘^»^, ' _ CiJ i-'Hi* - “If, '. 14^^ f 'fit - 4 Ai >4A.< V w,| '• »' X^a(4 » Introduction Pages l-I CONTENTS. PAET I. THE DESCEN r OR ORIGIN OF MAN. CHAPTER I. The Evidence op the Descent op Man pboji some Lower Form. PAG a Nature of the evidence bearing on the origin of man — Homologous structures in man and the lower animals — Miscellaneous points of correspondence — Development — Rudimentary structures, muscles, sense-organs, hair, bones, reproductive organs, &c. — The bearing of these three great chisses of facts on the origin of man .......... 5 CHAPTER II. On the Manner op Development of Man pro3i some Lower Form. Variability of body and mind in man — Inheritance — Causes of variability — Laws of variation the same in man as in the lower animals— Direct action of the conditions of life — Effects of the increased use and disuse of parts — Arrested development — Re- version— Correlated variation — Rate of Increase — Checks to increase — Natural selection — Man the most dominant animal in the world — Importance of his corporeal structure — The causes which have led to his becoming erect — Consequent changes of structure — Decrease in size of the canine teeth — Increased size and altered shape of the skull — Nakedness — Absence of a tail — Defenceless condition of man ..... 2G CHAPTER III. Comparison op the Mental PowEiis op Man and the I.ower Animals. The difference in mental power between the highest ape and (ho lowest savage, immense — Certain instincts in common — The emotions — Curiosity — Imitation — Attention — Memory — Imagi- nation— Reason — Progressive improvement — Tools and weapons XU Contents. PAGI used by animals — Abstraction, Sell’-consciousiiess — Language — Sense of beauty — Belief in God, spiritual agencies, super- stitions 65 CHAPTER IV. COMPAEISON OS' THE MeNTAL Pq-WERS OP MaN AND THE LOWEK Anbials — continued, Tlie moral sense — ^Fundamental proposition — The qualities of social animals — Origin of sociability — Struggle between opposed instincts — Man a social animal — The more enduring social in- stincts conquer other less persistent instinets — The social virtues alone regarded by savages — The self-regarding virtues acquired at a later stage of development — The importance of the judg- ment of the members of the same community on conduct — Transmission of moral tendencies — Summary . 97 C^HAPTER V. On the Developjient op the Intellectual and Moral Faculties during Primeval and Civilised Times. Advancement of the intellectual powers through natural selec- tion— Importance of imitation — Social and moral faculties — Their development within the limits of the same tribe — Natural selection as affecting civilised nations — Evidence that civilised nations were once barbarous . . . . 127 CHAPTER VI. On the Affinities and Genealogy op Man. Position of man in the animal series — The natui-al system genea- logical— Adaptive characters of slight value — ^Various small points of resemblance between man and the Quadrumana — Rank of man in the natural system — Birthplace and antiquity of man — Absence of fossil connecting-links — Lower stages in the genealogy of man, as inferred, firstly from his affinities and secondly from his structuie — Early androgynous condition of the Vertebrata — Conclusion . ... • . 1R> CHAPTER AHI. On the Races op Man. Tlie nature aud value of specific characters — Application to tlio races of man — Ai'guments in favour of, and opposed to, mnkiiig the so-called races of man as distinct species — Sub-species — Monogenists and polygenists— Convergence of character — Contents. xiu I’AQli Numerous points of resemblance in body and mind between tlie most distinct races of man — The state of man when he first spread over the earth — Each race not descended from a single pair— The extinction of races— The formation of races— The eftccts of crossing — Slight influence of the dii-ect action of the conditions, of life — Slight or no influence of natural selection — Sexual selection PAET II. SEXUAL SELECTION. CHAPTER VIII. Principles op Sexual Selection. Secondary sexual characters — Sexual selection — Manner of action — Excess of males — Polygamy — The male alone generally modified through sexual selection — Eagerness of the male — Variability of the male — Choice exerted by the female — Sexual compared with natural selection — Inheritance at corresponding periods of life, at corresponding seasons of the year, and as limited by sex — Relations between the several forms of inheri- tance— Causes why one sex and the young are not modified through sexual selection — Supplement on the proportional num- bers of the two sexes throughout the animal kingdom — The proportion of the sexes in relation to natural selection . . 207 CHAPTER IX. Secondary Sexual Characters in the Lower Classes op THE Animal Kingdom. These characters absent in the lowest classes — Brilliant colours — Mollusca — Annelids — Crustacea, secondary sexual characters strongly developed; dimorphism; colour; characters not ac- quired before maturity — Spiders, sexual colours of; stridulation by the males — Myriapoda ...... 200 CHAPTER X. Secondary Sexual Characters op Insects, Diversified structures possessed by the males for seizing the females — Differences between the sexes, of which the mean- ing is not understood — Difference in size between the sexes — Thysanura — Diptera — Hemiptera — Homoptera, musical powers XIV Contems. possessed by the males alone — Ortlioptera, musical instruments of the males, much diversified in structure; pugnacity; coloure— Neuroptera sexual differences in colour — Hymenoptera, pug- nacity and colours — Coleoptera, colours ; furnished with great horns, apparently as an ornament; battles; stridulating organs generally common to both sexes .... 274 CHAPTER XL IxsECTS, continued. — Order Lepidoptera. (bcttebflies and moths.) Courtship of butterflies — Battles — Ticking noise — Colours common to both sexes, or more brilliant in the males — Examples — Not duo to the dii'ect action of the conditions of life — Colours adapted for protection — Colours of moths — Display — Perceptive powers of the Lepidoptera — ^Variability — Causes of the difierence in colour between the males and females — Mimicry, female butterflies more brilliantly coloured than the males — Briglit colours of caterpillars — Summary and concluding remarks on the secondary sexual characters of insects — Birds and insects compared 307 CHAPTER Xn. Secondary Sexual Characters oe Fishes, Amphibians, and Reptiles. Fishes: Courtship and battles of the males — Larger size of the females — Males, bright colours and ornamental appendages; other strange characters — Colours and appendages acquired by the males during the breeding-season alone — Fishes with both sexes brilliantly coloured — Protective colours — The less con- spicuous colours of the female cannot be accounted for on the principle of protection — Male fishes building nests, and taking charge of the ova and young. Amphibians: Differences in structure and colour between the sexes — Vocal organs. Rep- tiles: Chelonians — Crocodiles — Snakes, colours in some cases protective — Lizards, battles of — Ornamental appendages — Strange differences in structure between the sexes — Colours — Sexual differences almost as great as with birds . . 330 CHAPTER XIII. Secondary Sexual Characters of Birds. Sexual differences — Law of battle — Special weapons — Vocal organs — Instrumental music — Love-antics and dances — Deco- rations, permanent and seasonal — Double and single annual moults — Display of ornaments by the mules . . 858 Contents. XV CHAPTER XIV. Birds — continued. VAGB Choice exerted by the female— Length of courtship— Unpaired birds— Mental qualities and taste for the beautiful— Preference or antipathy shewn by the female for particular males — Vari- ability of birds — ^Variations sometimes abrupt — Laws of varia- tion— Formation of ocelli — Gradations of character — Case of Peacock, Argus pheasant, and Urosticte . . lOl CHAPTER XV. B iBDS — continued. Discussion as to why the males alone of some species, and both sexes of others are brightly coloured — On sexually-limited inheritance, as applied to vaiious structures and to brightly- coloured plumage — Nidification in relation to colour — Loss of nuptial plumage during the winter .... 414 CHAPTER XVI. Birds — concluded. The immature plumage in relation to the character of the plumage in both sexes when adult — Six classes of cases — Sexual differ- ences between the males of closely-allied or representative species — The female assuming the characters of the male — Plumage of the young in relation to the summer and winter plumage of the adults — On the increase of beauty in the birds of the world — Protective colouring — Conspicuously-coloured birds — Novelty appreciated — Summary of the four chapters on birds ......... 4G3 CHAPTER XVII. Secondary Sexual Characters of Mammals. Tlie law of battle — Special weapons, confined to the males — Cause of absence of weapons in the female — Weapons common to botli sexes, yet primarily acquii-ed by the male — Other uses of such weapons — Their high importance — Greater size of the male— Means of defence — On the preference sliewn by either sex in the pairing of quadrupeds 500 CHAPTER XVIII. Secondary Sexual Characters of Mammals — continued. Voice — Remarkable sexual peculiarities in seals — Odour — Develop- ment of the hair— Colour of the hair and skin— Anomalous XVI Contents. case of the female being more ornamented than the male—'*'*" Colour and ornaments due to sexual selection — Colour acquired for the sake of protection — Colour, though common to both sexes, often due to sexual selection— On the disappearance of spots and stripes in adult quadrupeds — On the colours and orna- ments of the Quadrumana — Summary . . . 525 PAET III. SEXUAL SELECTION IN EELATION TO MAN, AND CONCLUSION'. CHAPTER XIX. Secondary Sexual Characters op Man « Difterences between man and woman — Causes of such differences, and of certain characters common to both sexes — Law of battle — Differences iu mental powers, and voice — On the influence of beauty in determining the marriages of mankind — Attention paid by savages to ornaments — Tlieir ideas of beauty in woman — The tendency to exaggerate each natural peculiarity . 55G CHAPTER XX. Secondary Sexual Charactees cp Man — continttccl. Oil the effects of the continued selection of women according to a different standard of beauty in each race — On the causes which interfere with sexual selection in civilised and savage nations — Conditions favourable to sexual selection during primeval times — On the manner of action of sexual selection with man- kind— On the women in savage tribes having some power ti) choose their husbands — Absence of hair on the body, and development of the beard — Colour of the skin — Summary . f)S5 CHAPTER XXL General Summary and Conclusion. Main conclusion that man is descended from some lower fonn — Manner of development — Genealogy of man — Intellectual and moral faculties — Sexual selection — Concluding remarks . GOil Supplemental Note 620 Index 625 THE DESCENT OF MAN; A^■D SELECTION IN EELATION TO SEX. INTRODUCTION. 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 pubhsh, 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 imphes 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 natui-alist hke Carl Vogt ventures to say in his address as President of the National Institution of Geneva (1869), “personne, en Europe “ au moms, n’ose plus soutenir la creation independante et de “ toutes pieces, des especes,” it is manifest that at least a largo 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 natm'al 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 unfortimately are still opposed to evolution in every form. In consequence of the views now adopted by most naturalists, and which will ultimately, as in every other case, be followed by li 2 Introduction. 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 organisms — their geographical distribution in past and present times, and their geological succession. The homological structure, embryological development, and rudi- mentary 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 should, however, always be kept before the mind. The sole object of this work is to consider, firstly, whether man, like every other species, is descended from some pre- existing form; secondly, the manner of his development; and thirdly, the value of the differences between the so-called 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 races— an enormous subject which has been fully discussed 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 indis- pensable basis for understanding his origin. I shall, therefore, take this conclusion for granted, and may refer my readers to the admii-able treatises of Sir cWles 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 anthropomor- phous apes ; for Prof. Huxley, in the opinion of most competent judges, has conclusively shewn that in every visible character rnn.-n 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 co-dcsccndant with other species of some ancient, lower, and extinct form, is not in Introdiictio7i. 3 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, Biichner, Eolle, &c.,^ and especially by Hackel. This last naturalist, besides his great work, ‘ Generelle Morphologie ’ (1866), has recently (1868, with a second edit, in 1870), pub- lished 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 fuUer than mine. "Wherever I have added any fact or view from Prof, flackel’s writings, I give his autho- rity in the text ; other statements I leave as they originally stood in my manuscript, occasionally giving in the foot-notes references to his works, as a confirmation of the more doubtful or interesting points. Hm-ing 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, p. 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.^ Consequently the second part of the present work, treating of sexual selection, has ex- tended to an inordinate length, compared with the first part; but this could not be avoided. 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 * 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 Darwinieune,’ 1869. ‘Der Mensch, im Lichte der Dar- win’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, p. 81) a very curious paper on rudimentary cha- racters, as bearing on the origin of man. Another work has (1869) been published by Dr. Francesco Barrage, bearing in Italian the title of “ Man, made in the image of God, “ was also made in the image of the “ ape.” * Prof. Hdckel 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. B 2 Inirodtiction. 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 reseiwe my essay for separate publication. Part I. THE DESCENT OE OKIGIN OF MAN. CHAPTER I. The Evidence oe the Descent of Man from some Lower Form. Natiire of the evidence bearing on the origin of man — Homologous structures in man and the lower animals — Miscellaneous points ol correspondence — Development — Rudimentary structures, muscles, sense- organs, hair, bones, reproductive organs, &c. — The bearing of these three great classes of facts on the origin of man. He who wishes to decide whether man is the modified descendant of some pre-existing form, would probably fii’st 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, &c. ? Is man subject to similar mal- conformations, the result of arrested development, of reduplication of parts, &c., and does he display in any of his anomalies rever- sion 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 sub-races, 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 succeeding generations ? And so with many other points. 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 6 The Descent of Man. Part I. 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 ju.st referred to may be conveniently deferred for a time : and we will first see how far the bodily structure of man shows traces, more or less plain, of his descent from some lower form. In succeeding chapters the mental powers of man, in comparison with those of the lower animals, will be considered. The Bodily Structure of Man. — It is notorious that man is constructed on the same general type or model as other mam- mals. 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, blood-vessels and internal viscera. The brain, the most important of all the organs, follows the same law, as shewn by Huxley and other anatomists. Bischoff,* 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 them brains perfectly agree ; nor could perfect agreement be expected, for otherwise their mental powers would have been the same. Vulpian ^ remarks : “ Les differences reelles qui existent entre I’encephale de “ rhomme et celui des singes superieurs, sont bien minimes. II “ ue fatit 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 ceux-ci 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 structui’e of the brain and all other parts of the body. It may, however, be worth while to specify a few pomts, not directly or obviously connected with structure, by which this correspondence or relationship is well shewn. Man is liable to receive from the lower animals, and to com- 1 ■ Grosshirnwiadungen des Men- schen.’ 1868, s. 96. The conclusions ot’ this author, .as well as those of Gratiolet and Aeby, concerning the urain, will be discussed by Prof. Huxley in the Appendix alluded to in the Preface to this edition. - ‘ Lef. sur la Phys.’ 1866, p. 890, as quoted bj' M. Dally, ‘ L’Ordre des Primates et leTransformisme,’ 1868, p. 29. Chap. I. Homological Structicrcs. 1 nmnicate to them, certain diseases, as hydrophobia, variola, the glanders, syphilis, cholera, herpes, &c. ; ® and this fact proves the close similarity* 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 non- contagious diseases as we are; thus Eengger,® who carefully observed for a long time the Cebus Azarce in its native land, found it liable to catai-rh, with the usual symptoms, and which, when often recui'rent, led to consumption. These monkeys suffered also from apoplexy, inflammation of the bowels, and cataract in the eye. The younger ones when shedding their milk-teeth 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 spirituous liquors : they will also, as I have myself seen, smoke tobacco with pleasure.” Brehm asserts that the natives of north-eastern 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 xntiable expression : when beer or wine was offered them, they turned away with disgust, but relished the juice of lemons.^ An American monkej'', 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 how similarly their whole nervous system is affected. Man is infested with internal ijarasites, sometimes causing ^ Dr. W. Lauder Lindsay has treated this subject at some length in the ‘Journal of Mental Science,’ July 1871; and in the ‘Edinburgh A'eterinary Review,’ July 1858. * A Reviewer has criticised (‘ British Quarterly Review,’ Oct. 1st, 1871, p. 472) what I have here said with much severity and con- tempt ; but as I do not use the term -dentitj’, I cannot see that I am greatly in error. There appears to me a strong analogy between the same infection or contagion pro- ducing the same result, or one closely similar, in two distinct ani- mals, and the testing of two dis- tinct fluids by the same chemical reagent. ’ ‘ Naturgeschichte der Sauge- thiere von Paraguay,’ 1830, s. 50. “ The same tastes are common to some animals much lower in the scale. Mr. A. Nicols informs me that he kept in Queensland, in Aus- tralia, three individuals of tlie JPhaseolarctus cinereus ; and that, without having been taught in any way, they acquired a strong taste for rum, and for smoking tobacco. ’ Brehm, ‘ Thierleben,’ B. i. 1804, s. 75, 86. On the Ateles, s. 105. For other analogous statements, sea s. 25, 107. 8 The Descent of Man. Paut 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.® Man is subject, bke other mammals, birds, and even insects,® to tliat 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.'® The whole process of that most important function, the reproduction of the species, is strikingly the same in all mam- mals, from the first act of courtship by the male," to the bii-tli and nurturing of the young. Monkeys are born in almost as helpless a condition as our o'wn infants ; and in certain genera the young differ fully as much in appearance from the adults, as do our children from their full-grown parents.'® 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.'® Man differs from woman in size, bodily strength, hairiness, &c., as well as in mind, in the same manner as do the ® Dr. W. Lauder Lindsay, ‘ Edin- burgh Vet. Review,’ July 1858, p. 13. ® With respect to insects see Dr. Laycock, “ On a General Law of Vital Periodicity,” ‘ British Association,’ 18-i'2. Dr. Macculloch, ‘ Silliraan’s North American Journal of Science,’ vol. svii. p. 305, has seen a dog sufl’ering from tertian ague. Here- after I shall return to this subject. '“ I have given the evidence on this head in my ‘ Variation of Ani- mals and Plants under Domestica- tion,’ vol. ii. p. 15, and more could be added. " “ Mares e diversii generibus “ Quadrumanorum sine dubio di- “ gnoscuut feminas humanas a ma- “ ribus. Primuru, credo, odoratu, “ postea aspectu. Mr. Youatt, qui “ diu in Hortis Zoologicis (Besti- “ ariis) medicus animalium erat, “ vir in rebus observandis cautus et “ sagax, hoc mihi certissime pro- “ bavit, et curatores ejusdem loci et “ alii e miuistris confirmaverunt. “ Sir Andrew Smith et Brehm no- “ tabant idem in Cynocephalo. 11- “ lustrissimus Cuvier etiam narrat “ raulta de hde re, qufi, ut opinor, “ nihil turpius potest indicari inter “ omnia hominibus et Quadrumanis “ communia. Narrat enim Cyno- “ cephalum quendam in furorem in- “ cidere aspectu feminarum ali- “ quarum, sed nequaquam accendi “ tanto furore ab omnibus. Sem- “ per eligebat juniores, et dignos- “ cebat in turba, et advocabat voce “ gestuque.” This remark is made with re- spect to Cynocephalus and the an- thropomorphous apes by Geofl'ro)’ Saint-Hilaire and F. Cuvier, ‘Hist. Nat. des Mammiferes,’ tom. i. 1824. Hu.vley, ‘ Man’s Place in Na- ture,’ 1863, p. 34. Chap. I. Homological Stmctures. 9 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 animals, especially the anthropomorphous apes, is ex- tremely close. Embryonic Development. — 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 arch-hke branches, as if to carry the blood ta branchiffi which are not present in the higher vertebrata, though the slits on the sides of the neck still remain (/, 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 “ 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. Startbng as this last assertion “ may appear to be, it is demonstrably true.” 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 coiDied from two works of undoubted accuracy.’® After the foregoing statements made by such high autho- rities, 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 '■* ‘ Man’s Place in Nature,’ 1863, p. 67. The human emhryo (upper fig.) is from Ecker, ‘leones Phys.,’ 1851-1859, tab. xxx. fig. 2. This embryo was ten lines in length, so that the drawing is much magnified. The embryo of the dog is fj'om BischolT, ‘ Entwicklungsgeschichto des Hunde-Eies,’ 184-5, tab. xi. fig. 42 B. This drawing is five times magnified, the embryo being twenty- five days old. The internal viscera have been omitted, and the uterine ap- pendages 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. Hiickel has also given analogous drawings in his ‘ Schopfuugsgeschichte.’ lO The Descent of Man. Paet L Fieri Upper figure human embiyo. from Ecker. Lower figure that of a dog, Ufa. rt- o from Bischoff. o. Fore-brain, cerebral hemispheres, &c. b. Mid-bniin, corpora quadrigeinina. c. Hind-braiii, cerebellum, medulla ob- longata. d. Eye. « Eiir. f. First visceral arch. q. Second visceral arch. H. Vertebral columns and muscles in process of devcloi>meut. i. Anterior \ (.^tremities. K. Posterior S L. Tail or os coccy.x. Chap. I. Rudiments. II like a true tail, “extending considerably beyond the rudi- “ mentary legs.”^® In the embryos of all air-breathing vertebrates, certain glands, called the corpora Wolffiana, correspond with, and act like the kidneys of mature fishes.’’' 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.’“ The great toe, as Prof. Owen remarks,’^ “ 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 “ 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 per- “ manent condition of this part in the quadrumana.” I will conclude with a quotation from Huxley,^’ 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 identieal with those of the animals “ immediately below him in the scale : without a doubt in “ these respects, he is far neai'er to apes than the apes are to “ the dog.” Eudiments. — This subject, though not intrinsically more important than the two last, will for several reasons be treated here more fully. Not one of the higher animals can be named which does not bear some j^art in a rudimentary condition ; and man forms no exception to the rule. Eudimentary organs must be distinguished from those that are nascent ; though in some cases the distinction is not easy. The former are either abso- lutely useless, such as the mammm 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 wo can hardly suppose that they were developed under the Prof. Wyman in ‘ Proc. of American Acad, of Sciences,’ rol. iv. I860, p. 17. ” Owen, ‘ Anatomy of V^erte- bratcs,’ vol. i. p. 533. ‘ Die Grosshirnwindungen des Jlenschen,’ 1868, s. 95. ‘Anatomy of Vertebrates,’ vol. li. p. 553. ‘ Proc. Soc. Nat. Hist.’ Boston, 1863, vol. ix. p. 183. ‘ Mjin’s Place in Nature,’ p. 65, I had written a rough copy of this chapter before reading a valu- able paper, “Caratteri rudimentali in ordine all’ origine del uomo ” (‘Aunuario della Soc. d. Nat.,’ Mo- dena, 1867, p. 81), by G. Canestrini, to which paper I am considerably indebted. Hackel has given admir- able discussions on this whole sub- ject, under the title of Dysteleology, in his ‘ Generelle Morphologie ’ and ‘ Schopfungsgeschichta.’ 12 Part 1. The Desce7it of Man. conditions -wliich 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. Eudimentary 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 reappearance through reversion— a circumstance well worthy of attention. 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 matmity), and also inheritance at a corresponding period of Hfe. 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. Eudiments, 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 Ufe. The process of reduction ’s probably often aided through the two principles of compensa- tion and economy of growth ; but the later stages of reduction, after disuse has done all that can fahly be attributed to it, and when the saving to be effected by the economy of growth would be very small,^^ are difficult to rmderstand. The final and complete suppression of a part, aheady 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,"^ I need here say no more on this head. Eudiments of various muscles have been observed in many parts of the human body;^® and not a few muscles, which ai’o Some good criticisms on this subject have been given by Messrs. Murie and Mivart, in ‘ Transact. Zoolog. Soc.’ 1869, vol. vii. p. 92. ‘ Variation of Animals and Plants under Domestication,’ vol. ii. pp. 317 and 397. See also ‘ Origin of Species,’ 5th edit. p. 535. For instance M. P.icnard (‘ An- nnlcs des Sciences Nat. 3rd series, Zoolog. 1852, tom. xviii. p. IS) de- scribes and figures rudiments of what ho calls the “ muscle pe'dieux de la main,” which he says is some- times “ infiniment petit.” Another muscle, called “ le tibial posWricur,” is generally quite absent in the hand, but appears from time to time in a more or less rudimentary con- dition. Chap. I. Rudiments. 13 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. Eemnants 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 plaiysma 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 axfilse, near the scapulae, &c., all of which must be referred to the system of the panni- culus. He has also shewn that the muscidus 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 especially “ liable to variation in arrangement.” Some few persons have the power of contracting the super- ficial 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 long-continued 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 above-mentioned branch is cousin in the seventh degree to the head of the other brancli. This distant cousin resides in another part of Prance ; 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 semi- human progenitors ; since many monkeys have, and frequently use the power, of largely moving their scalps up and down.^^ 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 Prof. W. Turner, ‘ Proc. Royal Emotions in Man and Animah,' Soc. Edinburgh,’ 1866-67, p. 65. 1872, p, 144. See my ‘ Expression of the 14 Past 1. The Descent of Man. of tho ^anrdcidxis ; 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 di-aw it upward.s ; another ■who could di’aw it backwards 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 dii-ection of danger; but I have never heard, on sufficient e'vidence, 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 anti-helix, tragus and anti-tragus, &c.) which in the lower animals strengthen and supxDort 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,-'’ after collecting all the known e'vidence 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 jn’oper muscles are likewise but very shghtly developed.'"’ I am also assui’ed 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 diu’ing a lengthened j)eriod 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 hea'vy birds, which, from inhabiting 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. Tho inability to move the ears in man and several apes is, however, partly com- pensated by tho freedom ■with which they can move the head in Canesti'ini quotes Hyrtl. (‘ An- nuario della Soc. del Naturalist!, Modena, 1867, j). 97) to the same effect. ‘ 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. Prof. A. Macalister, ‘ Annals and Mag. of Nat. History,’ vol. vii., 1871, p. 342. Chap. I, Rudimaits. 15 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 and, as I hear from Prof. Preyer, it is not rarely absent in the negro. The celebrated sculptor, Mr. Woolner, informs me of one little- peculiarity in the external ear, which he has often observed both ill men and women, and of which he perceived the full signi- ficance. 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 sub- sequently 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 w’oman. 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 ob- served a case in one of the spider- monkeys (^Ateles leelzebutJi) in our Zoological Gardens; and Dr. E. Ray Lankester informs me of another case in a chimpanzee in the gardens at Hamburg. The helix obviously con- sists 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,^^ tlie 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 i^oint would necessarily project inwards towards the centre, and probably a little outwards from the plane of the ear ; and this I believe to Mr. St. George Mivart, ‘Ele- Lemuroidea, in Messrs. Murie and P- 39G. Mivart’s excellent paper in ‘Tran- Sec also some remarks, and sact. Zoolog. Soc.’ vol. vii. 1869, pp the drawings of the cars of the 6 and 90. Fig 2. Human Ear, modelled and drawn by Mr. Woolner. a. The projecting point. i6 The Descent of Man. Part I. be their origin in many cases. On the other hand, Prof. L. Meyer, in an able paper recently pnbhshcd,” 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 wliich 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 micro- cephalous 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. Never- theless in some cases, my original view, that the points are vestiges of the tips of formerly erect and pointed eai-s, still seems to me probable. I thinlc 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 one-third of the whole ear. Two cases have been communicated to me, one in North America, and the other in England, in which the uiDper 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^‘ of the ear of a monkey, the Cynopithecus niyar, 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 inwards — in one of them, however, very narrowly. The following woodcut (No. 3) is an accurate copy of a photograph of the feetus 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, Avhen 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 fui-ther development, would give rise to a point projecting inwards. On the whole, it stiU seems to Ueber das Darwin’sche Spitzohr, ‘ The Expression of the Emo- Archiv fiir Path. Anat. und Phys. tions,’ p. 136. 1871, p. 485. Chap. I. Rudiments. 17 me probable that the points in question are in some cases, both in mmi and apes, vestiges of a former condition. Fig. 3. Fcetiis of an Orang. Exact copy of a photograph, shewing the form of the ear at this early age. 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 eye-ball. 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 mam- malian 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.®* r The sense of smell is of the highest importance to the greater number of mammals— to 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 Mfiller’s ‘ Elements of Physi- ology,’ Eng. translat., 1842, vol. ii. p. 1117. Owen, ‘ Anatomy of Verte- brates,’ vol. iii. p. 2G0 ; ibid, on the Walrus, ‘ Proc. Zoolog. Soc.’ November 8th, 1854. See also R. Knox, ‘ Great Artists and Anato- mists,’ p. 106. This rudiment .ap- parently is somewhat larger in Negroes and Austr.alians than in Europeans, see Carl Vogt, ‘Lectures on Man,’ Eng. translat. p. 129. C i8 The Descent of Man. Paict I. mucli more highly developed than in the white and civilised races 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 half-putrid 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 at- tended 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 con- tinually used. In those animals wliich 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,®'^ that the sense of smell in man “ is singularly effective “ in recalling vividly the ideas and images of forgotten scenes “ and places.” 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 haii’.^® 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 pale- coloured hairs on the limbs and other parts of the body, occasion- The account given by Humboldt of the powei' of smell possessed by the natives of South America is well known, and has been confirmed by others. M. Houzeau (‘ Etudes sur les Faculte's Mentales,’ &c., tom. i. 1872, p. 91) asserts that he re- peatedly 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 thj colouring matter of the mucou.s membrane of the olfactory region, as well as of the skin of the body. I h.ave, therefore, spoken in the text of the dark- coloured races having a finer sense of smell than the white races. See his paper, ‘ Mcdico-Chirurgical Tran- sactions,’ London, vol. liii., 1870, p. 276. ‘ The Physiology and Pathology of Mind,’ 2nd edit. 1868, p. 134. Eschricht, Ueber die Kichtung dcr Haare am menschlichen Kbrper, ‘ Muller’s Archiv fUr Anat. und Phys.’ 1837, s. 47. I shall often have to refer to this very curious paper. Chap. I. Rndiviejits. 19 ally become developed into “thickset, long, and rather coarse “ dai-k haii’s,” -when abnormally nourished near old-standing inflamed surfaces.®^ I am informed by Sir James Paget that often several members of a family have a fe-w 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 bans project from the hairy covering of the superciliary ridges in some baboons. The fine wool-hke ham, or so-called lanugo, with which the human foetus dui-iog the sixth month is thickly covered, offers a more cmious 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 tills kind was observed by Eschrichf’’ 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 dmection 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 cover- ing 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 abnor- mal condition of the teetb.^' Prof. Alex. Brandt informs me that he has compared the hair from the face of a man thus charac- terised, aged thirty-five, 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 Paget, ‘Lectures on Surgical Pathology,’ 1853, vol. i. y. 71. Eschricht, ibid. s. 40, 47. “ 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 Eussia, with these peculiarities. I have received drawings of both from Paris. 20 The Descent of Man. Part I, been assured by a surgeon to a hospital for children, have their backs covered by rather long silky hairs ; and such cases pro- bably come under the same head. It appears as if the posterior molar or wisdom-teeth 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 chim- panzee 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.*'-^ In the Melanian races, on the other hand, the wisdom-teeth are usually fitrnished with three separate fangs, and are generally sound ; they also differ from the other molars in size, less than in the Caucasian races.'*^ 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,"'* 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 chilclren, as the jaw does not grow large enough for the perfect development of the normal number.*® With respect to the alimentary canal, I have met with an account of only a single rudiment, namely the vermiform append- age of the cEBCum. The csecum is a branch or diverticulum of the intestine, ending in a cul-de-sac, and is extremely long in many of the lower vegetable-feeding mammals. In the marsupial koala it is actually more than thrice as long as the whole body.*® It is sometimes produced into a long gradually-tapering point, and is sometimes constricted in parts. It appears as if, in con- sequence of changed diet or habits, the csecum had become much *^ Dr. Webb, ‘ Teeth in Man and the Anthropoid Apes,’ as quoted by Dr. C. Carter Blake in ‘ Anthropo- logical Review,’ July 1867, p. 299. Owen, ‘ An.atomy of Verte- brates,’ vol. iii. pp. 320, 321, and 325. ** ‘ On the Primitive Form of the Skull,’ Eng. translat. in ‘Anthropo- logical Review,’ Oct. 1868, p. 426. 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 are on the road towards atrophy or elimination. Owen, ‘ Anatomy of Verte- brates,’ vol. iii. pp. 416, 434, 441. Chap I. Rudiments. 21 shortened in various animals, the vermiform appendage being left as a rudiment of the shortened part. That tlus appendage is a rudiment, we may infer from its small size, and from the evidence which Prof. Canestrini^'^ 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 two-thirds 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 csecum, 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 inflam- mation.'** In some of the lower Quadrumana, in the Lemuridas and Carnivora, as well as in many marsupials, there is a passage near the lower end of the humerus, called the supra-condyloid fora- men, 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 hook -like process of bone, completed by a band of ligament. Dr. Struthers,'*® 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 pre- sent, the great nerve invariably passes through it; and this clearly indicates that it is the homologue and rudiment of the suiDra-condyloid 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 in the higher Quadrumana it is absent. There is another foramen or perforation in the humerus. ‘Annuario della Soc. d. Nat.’ Slodenaj 1867, p. 94. ' ^ M. C. Martins (“ De I’Unite' Organique,” in ‘ Revue des Deu.K Moudes,’ June 15, 1862, p. 16), and Hiickel (‘ Generelle Morphologie,’ B. ii. 8. 278), have both remarked on the singular fact of this rudi- ment sometimes causing death. With respect to inheritance. Dee Dr. Struthers in the ‘ Lancet,’ Feb. 15, 1873, and another im- portant 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 im- portant memoir on this process bv Dr. Gruber, in the ‘ Bulletin d'e I’Acad. Imp. de St. Petersbourg, tom. xii. 1867, p. 448. 22 The Descent of Man. Pabt L occasionally present in man, which may be called the inter- condyloid. This occurs, but not constantly, in various anthro- poid and other apes,''" and hkewise 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®^ has collected the following evidence on this head : Prof. Broca “ noticed the perforation in four and a “ half per cent, of the arm-bones collected in the ‘ Cimetiere du “ Slid,’ 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 thirty-two were perforated ; but this extraordi- “ nary 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 Eeindeer period ; whilst M. Leguay, in “ a sort of dolmen at Argenteuil, observed twenty-five per cent, “to be perforated; and M. Pruner-Bey found twenty-six per “ cent, in the same condition in bones from Vaureal. Nor should " it be left unnoticed that M. Pruner-Bey states that this con- “ dition is common in Guanche skeletons.” It is an interesting fact that ancient races, in tliis 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 animal-like 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,"'* to form a small external rudiment of a tail. The os coccyx is short, usually including only four vcrtebrce, all anchylosed together: and these are in a rudi- Ml'. St. George Mivart, ‘ Trans- act. Phil. Soc.’ 1867, p. 310. 51 << On the Cares of Gibraltar,” ‘ Transact. Internat. Congress of Prehist. Arch.’ Third Session, 1869, p. 159. Prof. Wyman has lately shewn (Fonrth Annual Report, Pea- body Museum, 1871, p. 20), that this perforation is present in thirty-one per cent, of some human remains from ancient mounds in the Western United States, and in Florida. It frequently occurs in the negro. =2 Quatrefages has lately collected the evidence on this subject. ‘ Revue des Cours Scientifiques,’ 1867-1868, p. 625. In 1840 Fleischm.ann ex- hibited 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 Niederliindischeu Archivfilr Zoologie, Decemberl871). Chap. I. Rudiments. 23 mentary condition, for they consist, with the exception of the basal one, of the centrum alone.®* They are furnished with some small muscles ; one of which, as I am informed by Pyof. Tm-ner, has been expressly described by Theile as a rudimentary repetition of the extensor of the tail, a muscle which is so largely developed in many mammals. The spinal cord in nian extends only as far downwards as the last dorsal or first lumbar vertebra; but a thread-like struc- tm’e (the filum terminale) rims 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. Tui-ner 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 in- debted to Prof. Tui-ner, shews how closely the os coccyx corre- sponds 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 body, though not at the extremity. The re2Droductive system offers various rudimentary struc- tures; 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 occiuTence of such rudiments is as difficult to explain, on the belief of the separate creation of each sjiecies, as in the foregoing cases. Hereafter I shall have to recur to these rudiments, and shall shew that their presence generally depends merely on inheri- tance, that is, on parts acquired by one sex having been partially transmitted to the other. I will in this jilace only give some instances of such rudiments. It is well known that in the males of all mammals, including man, rudimentary mammie 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 Owen, ‘ On the Nature of Limbs,’ 1849, p. 114. 24 The Descent of Man. Pakt 1 measles. The vesicula prosiatica, which has been observed, in many male mammals, is now universally acknowledged to be the homologue of the female uterus, together with the con- nected 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 tho case of those mammals in which the true female uterus bifoi’cates, for in the males of these the vesicula hkewiso bifurcates.®^ Some other rudimentary structures belonging to the reproductive system might have been here adduced.®® 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, &c., is utterly inexplicable.®® 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 imderstand, on the principle of Leuckart, in Todd’s ‘ Cyclop, of Anat.’ 1849-52, 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. See, on this subject, Owen, ‘Anatomy of Vertebrates,’ vol. iii. pp. .675, 676, 706. Prof. Bianconi, in a recently published work, illustrated by ad- mirable engravings (‘ La The'orie Darwinienne et la erdation dite in- de'pendante,’ 1874), endeavours to show that homological structures, in the above and other cases, can be fully explained on mechanical prin- ciples, in accordance with their uses. No one has shewn so well, how ad- mirably such structures are adapted for their final purpose ; and this adaptation can, as I believe, be explained through natui'al 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 prin- ciple, 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 mammie of male quadrupeds, or the wings of certain beetles, existing under the soldered wing-covers, 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 natural- ists seems to me left unshaken, that homological structures are in- explicable on the principle of mere adaptation. Chap. I. Rudiments. 25 Tariations Eupei'Teniug 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, &c., 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 in- dicated. Thus we can imderstand 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 geolo- gical succession. It is only our natural prejudice, and that arrogance which made our forefathers declare that they were descended from demi-gods, 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 believed that each was the work of a scixirate act of creation. 26 The Descent of Man. Paut t V CHAPTER n. On the Manner of Development of Man from some Lower Form. Variability of body and mind in man — Inheritance — Causes of variability — Laws of variation the same in man as in the lower animals — Direct action of the conditions of life — Effects of the increased use and disuse of parts — Arrested development — Reversion — Correlated variation — Rate of increase — Checks to increase — Natural selection — Man the most dominant animal in the world — Importance of his corporeal structure — The causes which have led to his becoming erect — Consequent changes- of structure — Decrease in size of the canine teeth — Increased size and altered shape of the skull — Nakedness — Absence of a tail — Defenceless condition of man. It is manifest that man is now subject to much variability. No two individuals of the same race are quite ahke. 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.^ 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 Australia — the 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.^ 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.^- The muscles are eminently variable: thus those of the foot were found by Prof. Turner^ not to be strictly alike in any two out of fifty bodies; and in some the deviations were considerable. > ‘ Investigations in Military and Anthropolog. Statistics of American Soldiers,’ by B. A. Gould, 1869, p. 256. “ 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 Sand- wich Islanders, Prof. J. Wyman, ‘ Obseiwations on Crania,’ Boston, 1868, p. 18. ^ ‘Anatomy of the Arteries,’ by R. Quain. Preface, vol. i. 1844. * ‘Transact. Royal Soc. Eldin- burgh,’ vol. xiiv. pp. 175, 189. Chap. II. Manner of Developinetit. 27 He adds, that the power of performing the appropriate move- ments must haye been modified in accordance with the several deviations. Mr. J. Wood has recorded® the occui-rence of 295 muscular variations in thirty-six subjects, and in another set of the same number no less than 558 variations, those occui'ring on both sides of the body being only reckoned as one. In the last set, not one body out of the thirty-six 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 twenty-five distinct abnormalities. The same muscle sometimes varies in many ways: thus Prof. Macabster describes® no less than twenty distinct variations in the palmar is accessorius. The famous old anatomist, Wolff,'' insists that the internal viscera are more variable than the external parts : Nulla parti- cula est quse non aliter et aliter in aliis se liaheat Jiominibus. He has even written a treatise on the choice of typical examples of the viscera for representation. A discussion on the beau-ideal of the liver, hmgs, Iddneys, &c., as of the human face divine, sounds strange in oiu’ ears. 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 men- tions 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. Eengger, 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.® I have elsewhere® so fully discussed the subject of Inheritance, that I need hero add hardly anything. A greater munber of ® ‘Proc. Royal Soc.’ 1867, p. 544; also 1 868, pp. 483, 524. There is a previous paper, 1866, p. 229. ® ‘ Proc. R. Irish Academy,’ vol. X. 1868, p. 141. ^ ‘Act. Acad. St. Petersburg,’ 1778, p.ai-t ii. p. 217, ® Biehm, ‘ Tliierleben,’ B. i. s. 58, 87. Rengger, ‘ Saugethiere von Paragu.ay,’ s. 57. “ ‘ Variation of Animals and Plants under Domestication,’ vol ii. chap. .vii. 0 9 Pabt I, 2S The Descent of Man. facts have been collected with respect to the transmission of the most trilling, 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 quahties, their transmission is manifest in our dogs, horses, and other domestic animals. Besides special tastes and habits, general intelligence, courage, bad and good temper, &c., are certainly transmitted. With man we see similar facts in almost every family ; and we now know, through the admirable labours of Mr. Gallon,'® 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 deteri- orated 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 diflerent grades of rank, and following {lifferent 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." 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 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. Ko race or body of men has been so '® ‘ Hereditary Genius : an In- quiry into its Laws and Conse- quences,’ 1869. Mr. Bates remarks (‘ The Natu- ralist 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 “ iu the shape of the head ; one “ man had an oval visage with fine “ features, and another was quite “ Mongolian in breadth and pro- “ minence of cheek, spread of nos- “ trils, and obliquity of eyes.” Blumenbach, ‘ Treatises on An- thropolog.’ Eng. translat., 1865, p. 205. Chap. II. Manner of Development. 29 completely subjugated by other men, as that certain individuals should be preserved, and thus unconsciously selected, from some- how excelhng in utility to their masters. Nor have certain male and female individuals been intentionally picked out and matched, except in the well-known case of the Prussian grena- diers ; and in this case man obeyed, as might have been ex- pected, the law of methodical selection ; for it is asserted that many taU men were reared in the villages inhabited by the grenadiers and their taU wives. In Sparta, also, a form of selec- tion was followed, for it was enacted that all children should be examined shortly after birth; the well-formed and vigorous being preserved, the others left to perish.^^ 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 weU-known law that widely-ranging 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 Mitford’s ‘ History of Greece,’ vol. i. p. 282. It appears also from a passage in Xenophon’s ' Memora- bilia,’ B. ii. 4 (to which my atten- tion has been called by the Rev. J. N. Hoare), that it was a Avell recognised principle with the Greeks, that men ought to select their wives with a view to the health and vigour of their children. The Gre- cian 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 oftec 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 cause is plain. And to lament the consequence is vain.” (The Works of J. Hookham Frere, vol. ii. 1872, p. 334.) The Descent of Man. Pal,!' L 30 Quatrcfagcs, that I need here only refer to their works.’< Mon- strasities, 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 bj' Isidore Geoffrey St.-Hilairo.'° 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 foimd 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 long-lost characters through reversion. And lastly, correlated variation. All these so-called 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 but several are so important, that they must be treated at con- siderable length. The direct and definite action of changed conditions. — This is a most perplexing subject. It caimot be denied that changed con- ditions 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 con- clusion ; 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 rend- ered in some degree plastic. In the United States, above 1,000,000 soldiers, who served in the late war, were measui'ed, and the States in which they were Godron, ‘ De I’Espfece,’ 1 859, tom. ii. livre 3. Quatrefages, ‘ Unite ‘ Thierleben,’ B. i. s. 79, 82. G 82 The Descent of Man. Paht [. actually closed for a time against the caravan. It deserves notice that these baboons thus acted in concert. Mr. Wallace*' on three occasions saw female orange, 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 bim ; and the before mentioned baboon at the Cape of Good Hope prepared mud for the purpose. 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 most or all birds with their nests. The Duke of Argyll*^ remarks, that the fashioning of an implement for a special purpose is absolutely pecuUar to man ; and he considers that this forms an immeasurable gulf between him and the brutes. This is no doubt a very important dis- tinction ; but there appears to me much truth in Sir J. Lubbock’s suggestion,*® that when primeval man first used flint-stones 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 tem- porary 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 l)rotect itself from the heat of the sun by throwing a straw-mat <> ‘ The Malay Archipelago,’ vol. 145, 147. 1. 1869, p. 87. ** ‘ Prehistoric Times,' 1865, p, ‘ Primeval Man,’ 1869, pp. 473, &c Chap. III. Mmtal Powers. 83 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 progenitors of man. Abstraction, General Conceptions, Self-consciousness, Mental Individuality. — 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. It either refers what he perceives with his senses to a mental concept, then so do both.*^ 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 to be discovered and hunted ? It may be freely admitted that no animal is self-conscious, 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 self-consciousness. On the other hand, as Buchner has remarked, how little can the hard- worked wife of a degraded Australian savage, who uses very few abstract wj rds, and cannot count above four, exert her self- ^nsciousness, or reflect on the natuz’e of her own existence. It is generally admitted, that the higher animals possess memory, D * r la a letter to ‘ Confe'rences sur la Throne Prof. Max Muller, in the ‘ Birming- Darwinienne,’ French translat ham News, May 1873. 1869, p. 132. 84 The Descent of Man. Past i. 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, &c., 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, &c. ; 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 imperceptible degrees. That animals retain their mental individuality is unquestion- able. 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 abid® amid all mental moods and all material changes. . . . “ The tSkching that atoms leave their impressions as legacies to " other atoms falling into the places they have vacated is con- " tradictory of the utterance of consciousness, and is therefore " false ; but it is the teaching necessitated by evolutionism, con- “ sequently the hypothesis is a false one.”‘® Language. — 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.” In Paraguay the Cd)us azarce when excited utters at least six distinct sounds, which excite in other monkeys similar emotions.''® The movements of the features and gestures of monkeys are understood by us, and they partly understand ours, as Eengger and others declare. It is a more remarkable fact that the dog, since being domesticated, has learnt to bark'® in at least four or five distinct tones. Although barking is a new art, no doubt the wild parent-species 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, ns " The Rev. Dr. J. M‘Cann, ‘ Anti- " Rengger, ibid. s. 45. Darwinism,’ 1869, p. 13. See my ‘ Variation of Ani- Quoted in ‘Anthropological Re- mals and Plants under Domcstira- -iew ’ 1864, p. 158. tion,’ vol. L p. 27. )hap. III. Mental Powers. 85 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 par- ticular attention to the subject, the domestic fowl utters at least a dozen significant sounds.®® The habitual use of articulate language is, however, peculiar to man ; but he uses, in common with the lower animals, inarti- culate cries to express his meaning, aided by gestures and the movements of the muscles of the face.®^ This especially holds good with the more simple and vivid feeUngs, which are but little connected with our higher intelligence. Our cries of pain, fear, sm-prise, 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 con- necting definite sounds with definite ideas ; for it is certain that some parrots, which have been taught to speak, connect un- erringly words with things, and persons with events.®^ The lower animals differ from man solely in his almost infinitely larger power of associating together the most diversified ” ‘Facult^s Mentales des Ani- maux,’ tom. ii. 1872, p. 346-349. See a discussion on this subject in Mr. E. B. Tylor’s very interesting work, ‘ Eesearches into the Early History of Mankind,’ 1865, chaps, ii. to iv. I have received several detailed accounts to this efl'ect. Admiral Sir J. Sulivan, whom 1 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 veil 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 J. Sulivan’s father, he used to add to the “ good moiming ” a short sentence, which wa.s 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 (say- ing “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. 1 could add several other such cases. 86 The Descent of Man. Pabt I. Bounds and ideas; and this obviously depends on the high development of his mental powers. As Horne Took, 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 in- stinctive 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 imconsciously developed by many steps.“ 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 aU the kinds which sing, exert their power instinctively ; but the actual song, and even the call-notes, are learnt from their parents or foster-parents. These sounds, as Daines Barrmgton‘‘ has proved, “ are no more innate than language is in man.” The first attempts to sing “ may bo compared to the imperfect “ endeavour in a child to babble.” The young males contmue practising, or as the bird-catchers say, “ recording,” for ten or eleven months. Their first essays show 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 canary-birds educated in the Tyrol, teach and transmit their new song to their offspring. - The slight natural differences of song m 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 tendency to acquire an art is not peculiar to man. With respect to the origin of articulate language, after having read on the one side the highly interesting works of Mr. Heus- 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, whicli, in the development of language, “ works both consciously and un- " consciously consciously as re- “ gards the immediate end to be “ attained ; unconsciously as regards “ the further consequences of the “ act.” ** Hon. Daines Bari’ington in ‘ Philosoph. Transactions,’ 1773, p. 262. See also Dureau de la M.alle, in ‘ Ann. des. Sc. Nat.’ 3rd senes. Zoolog. tom. X. p. 119. Chap. III. Me^ital Powers. 87 leigh Wedgwood, the Eev. F. Farrar, and Prof. Schleicher,®^ 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 gibbon-apes at the present day ; and we may conclude from a widely-spread 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 expres- sive of various complex emotions. The strong tendency in our nearest allies, the monkeys, in microcephalous idiots,®" 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 signal-cries of danger to their fellows ; and since fowls give distinct warnings for danger on the ground, or in the sky from hawks (both, as well as a third cry, intelh'gible to dogs),®® may not some unusually wise ape-like animal have imitated the growl of a beast of prey, and thus told his fellow-monkeys the nature of the expected danger ? This would have been a first step in the formation of a language. 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 pro- genitor of man must have been more highly developed than in ‘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. Rikkers into English, under the title of ‘ Darwinism tested by the Science of Language,’ 1869 Vogt, ‘Me'moire sur les Micro- ce'phales,’ 1867, p. 169. With re- spect to savages, I have given some facts in my ‘ Journal of Researches,’ &c., 1845, p. 206. See clear evidence on this head in the two works so often quoted, by Brehm and Rengger. Houzeau gives a very curious .account of his observations on this subject in his ‘ Facultes Mentales des Animaux,’ tom. ii., p. 348. 88 7 fie Descent of Man. Part L 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 facihtated by some form of language, for the dumb, deaf, and blind girl, Laura Bridgman, was observed to use her fingers whilst dreaming. 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 brain-disease 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.®* There is no more improb- abihty 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 hand-writing is certainly inherited.®' Several writers, more especially Prof. Max Miiller,®® 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 impossible barrier is formed between them and man.®* With respect to animals, I have already »» See remarks on this head by Dr. Maudsley, ‘ The Physiology and Pathology of Mind,’ 2nd edit. 1868, p. 199. Many curious cases have been recorded. See, for instance. Dr. Bateman ‘On Aphasia,’ 1870, p. 27, 31, 53, 100, &c. Also, ‘ Inquiries Concerning the Intellectual Powers,’ by Dr. Abercrombie, 1838, p. 150. ‘The Variation of Animals and Plants under Domestication,’ vol. ii. p. 6. Lectures on ‘ Mr. Darwin’s Phi- losophy of Language,’ 1873. The judgment of a distin- guished philologist, such as Prof. Whitney, will h.ive far more weight on this point than anything that I can say. He remarks (‘ Oriental and Linguistic Studies,’ 1873, p. 2&7), in speaking of Block’s views : “ Because on the grand scale lan- “ guage is the necessary auiiliaiy “ of thought, indispensable to the “ development of the power of Chap. III. Mental Powers. 89 endeavoured to show 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 deaf-mutes, it seems to me in- credible, that they should be able to coimect 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 mtelligent animals ; as Mr. Leslie Stephen observes,®* '' 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 degree, as the capacity to “ speak.” 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.®® 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 “ thinking, to the distinctness and “ variety and complexity of cogni- “ tions to the full mastery of con- “ sciousness ; therefore he would “ fain make thought absolutely im- “ possible without speech, identify- “ ing the faculty with its instru- “ ment. He might just as reason- “ ably assert that the human hand “ cannot act without a tool. With “ such a doctrine to start from, he “ cannot stop short of Muller’s “ worst paradoxes, that an infant “ (in fans, not speaking) is not a “ human being, and that deaf-mutes “ do not become possessed of reason " until they learn ;o twist their “ fingers into imitation of spoken “ words.” Max Muller gives in italics (‘Lectures on Mr. Darwin’s Philosophy of Language,’ 1873, third lecture) the following aphor- ism : “ There is no thought with- “ out words, as little as there are “ words without thought.” What a strange definition must here be given to the word thought 1 ®* ‘ Essays on Free-thinking,’ &c., 1873, p. 82. ®® See some good remarks to this effect by Dr. Maudsley, ‘ The Phy- siology and Pathology of Mind,’ 1868, p. 199. 90 Tfic Desce7it of Man. Pakt 1. organs, which with long-continued 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.®® 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 anything more definite, considering our ignorance with respect to the successive stages of development through which each creature has passed. The formation of different languages and of distinct species, and the proofs that both have been developed through a gradual process, are curiously parallel.®^ But we can trace the formation of many words further back than that of species, for we can perceive how tliey 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 long- continued use, and so forth. The frequent presence of rudi- ments, both in languages and in species, is still more remarkable. The letter m in the word am, means 1 ; so that in the expres- sion I am, a superfluous and useless rudiment has been retained. In the spelling also of words, letters often remain as the rudi- ments 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 arti- ficially 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 birth-places. Distinct languages may be crossed or blended together.®® We see variability in every tongue, and new 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 ana closely investigating its habits, he has never known it, in a state of nature. display any unusual capacity for imitation. ‘ Reseai’ches in Zoology,’ 1834, p. 158. See the very interesting pa- rallelism between the development of species and languages, given by Sir C. Lyell in ‘ The Geolog. Evi- dences of the Antiquity of Man,’ 1863, chap, xxiii. Sec remarks to this effect by Chap. 111. Mental Powers. 91 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 has well re- marked : — “ 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 selection. 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 lan- guages, 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 Ame- “ rican languages.”'® But it is assuredly an error to speak of any language as an art, in the sense of its having been elabor- ately and methodically formed. Philologists now admit that conjugations, declensions, &c., 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 sheU,^^ 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 special- isation 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 the Rev. F. W. Farrar, in an in- teresting article, entitled ‘Philo- logy and Darwinism’ in ‘Nature,’ March 24th, 1870, p. 528. ‘ Nature,’ Jan. 6th, 187C p. 267. ” Quoted by C. S. Wake, ‘Chap- ters on Man,' 1868, p. 101. Buckland, ‘Bridgewater Trea- tise,’ p. 411. 92 The Desce7it of Man. Past I. borrowed expressive words and iiseful forms of construction from various conquering, conquered, or immigrant races. 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.’^ Nor, as we have seen, does the faculty of articulate speech in itself offer any insuperable objection to the belief that man has been developed from some lower form. Sense of Beauty. — This sense has been declared to be peculiar to man. I refer here only to Ihe 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 humming-birds, and the playing passages of bower-birds 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 attoactions 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 See .some good remarks on the J. Lubbock, ‘Origin of C vilisntion, simplificjiiion of languages, by Sir 1870, p. 278. Chap. III. Mental Powers. 93 liighly 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 am’mals. 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 same colours, graceful shading and forms, and the same sounds. 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 samp 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 land- scape, 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 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, hkewise capri- cious in their affections, aversions, and sense of beauty. There is also reason to suspect that they love novelty, for it own sake. Belief in God — Religion. — There is no evidence that man was aboriginally endowed with the ennobhng behef 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 ” ‘The Spectator,’ Dec. 4th, 1869, p. 1430. 94 The Descent of Man. Pabt T. words in their languages to express such an idea/^ The question is of course wholly distinct from that higher one, whether there exists a Creator and Euler of the universe ; and this has been answered in the affirmative by some of the highest intellects that have ever existed. 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’® has remarked, " Some explan- “ ation 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.”^“ But until 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, ‘ Pre- historic Times,’ 2nd edit. 1869, p. 664 ; and especially the chapters on Religion in his ‘Origin of Civilisa- tion,’ 1870. ‘ The Worship of Animals and Plants,’ in the ‘ Fortnightly Review,’ Oct. 1, 1869, p. 422. Tylor, ‘ Early History of Man- kind,’ 1865, p. 6. See also the three striking chapters on the De- velopment of Religion, in Lubbock’s ‘ Origin of Civilisation,’ 1870. In a like manner Mr. Herbert Spencer, in his ingenious essay in the ‘ Fort- nightly Review’ (May 1st, 1870, p. 635), 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 power- ful, 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 womhipped as a god. Nevertheless I cannot but suspect that there is a still earlier and ruder stage, when Chap. III. Mental Powers. 95 the. faculties of imagination, curiosity, reason, &c., had been fairly well developed in the mind of man, his dreams would not have led him to believe in spirits, any more than in the case of a dog. 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 full- grown and very sensible animal, was lying on the lawn during a hot and still day ; but at a little distance a slight breeze occa- sionally 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. Hor 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,” fear, reverence, gratitude, hope for the future, and perhaps other elements. No being could experience so complex an emotion anything which manifests power or movement is thought to be endowed with some form of life, and with mental faculties analogous to our own. See an able article on the ‘ Physical Elements of Religion,’ by Mr. L. Owen Pike, in ‘ Anthropolov, Review,’ April, 1870, p. Ixiii. 96 The Descent of Man. Part I. 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.’* 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 of — such as the sacrifice of human beings to a blood- loving god ; the trial of innocent persons by the ordeal of poison or fire ; witchcraft, &c. — 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” 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. ‘ Religion, Moral, &c., der Dar- win’sehen Art-Lehre,’ 1869, s. 53. It is said (Dr. W. Lauder Lindsay, ‘Journal of Mental Science,’ 1871, p. 43), that Bacon long ago, and the poet Burns, held the same notion. ‘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. Chap. H'. Moral Setisc. 97 CHAPTER IV. COMPABISON OF THE MeNTAL PoWEES OF MaN AND THH Lower Animals — continued. The moral sense — Fundamental proposition — The qualities of social animals — Origin of sociability — Struggle between opposed instincts — Man a social animal — The more enduring social instincts conquer other less persistent instincts — The social virtues alone regarded by savages — The self-regarding tdrtues acquired at a later stage of development — The importance of the judgment of the members of the same community on conduct — ^Transmission of moral tendencies — Summary. I FULLY subscribe to tbe judgment of those writers^ 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* 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 hesita- tion to risk his hfe for that of a fellow-creature ; 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 ?” ® This great question has been discussed by many writers * 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 in- ’ See, for instance, on this subject, Quatrefages, ‘Unite de I’Espbce Humaine,’ 1861, p. 21, &c. ’ ‘ Dissertation on Ethical Philo- sopliy,’ 1837, p. 231, &c. * ‘ Metaphysics of Ethics,’ trans- lated by J. W. Semple, Edinburgh, 1836, p. 136. ‘ Mr. Bain gives a list (‘ Mental and Moral Science,’ 1868, p. 543- 725) of twenty-six 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. H 98 The Descent of Man. 1’abt T. dependent interestj as an attemjit to see how for 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 probable — namely, that any animal whatever, endowed with well-marked social instincts,® 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 mau. 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 ® Sir B. Brodie, after observing that man is a social animal (‘ Psy- chological 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 pex'sons, as they did long ago to Marcus Aurelius. Mr. J. S. Mill speaks, in his celebrated work, ‘ Utilitarian- ism,’ (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 out-growth from it ; “ capable, like them, in a certain “ small degree of springing up spon- “ taneously.” But in opposition to all this, he also remarks, “if, as is “ my own belief, the moral feelings “ ai-e not innate, but acquired, they “ are not for that reason less natu- “ ral.” 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 ac- quired by each individual during his lifetime. On the general theory of evolution this is at least ex- tremely improb.able. 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. Chap. IT. Moral Sense. 99 behind it a very vivid impression. It is clear that many in- stinctive 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 how- ever 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 foundation-stone. Lastly, habit in the individual would ultimately play a very important part in guiding the conduct of each member ; for the social in- stinct, together with sympathy, is, like any other instinct, greatly stren^hened by habit, and so consequently would be obedience to the wishes and judgment of the community. These several subordinate propositions must now be discussed, and some of them at considerable length. 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 widely different 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 hive-bees, there can hardly be a doubt that our unmarried females would, hke the worker-bees, think it a sacred duty to kiU their brothers, and mothers would strive to kill their fertile daughters ; and no one would think of interfering.® Nevertheless, the bee, or any ® Mr. H. Sidgwick remarks, in an able discussion on this subject (the ‘Academy,’ June 15th, 1872, (p. 231), “ a superior bee, we may “ feel sure, would aspire to a milder “ solution of the population ques- “ tion.” Judging, however, from the habits of many or most savages, man solves the problem by female infanticide, polyandry and promis- cuous intercourse ; therefore it may well be doubted whether it would be by a milder method. Miss €obbe, in commenting (‘ Darwinism in Morals,’ ‘Theological Review,’ April, 1872, p. 188-191) on the same illustration, says, the prin- ciples 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 fiir as to say that if the theory of ethics advocated in this chapter were ever H 2 100 The Descent of Man. Paet I. 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 he a struggle as to which impulse should be followed; and satisfaction, dissatis- faction, 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 coui’se 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. Sociahility. — Animals of many kinds are social ; we find even distinct species living together ; for example, some American monkeys ; and united fiocks 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, &c., 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 die united senses of all. Every sportsman knows, as Dr. Jaeger remarks,^ how difficult it is to approach animals in a herd or troop. Wild horses and cattle do not, I believe, make any danger-signal ; but the attitude of any one of them who firat discovers an enemy, warns the others. Babbits stamp loudly on the ground with their hind-feet as a signal : sheep and chamois do tho same with their forefeet, uttering likewise a whistle. Many birds, and some mammals, post sentinels, which in the case of seals are said* generally to be the females. The leader generally accepted, “ I cannot but earth is not held by many person* “ believe that in the hour of their on so weak a tenure. “ triumph would be sounded the ' ‘ Die Darwin'sche Theorie,’ s “ knell of the virtue of mankind !” 101. It is to be hoped that the belief in " Jlr. K. Brown in ‘ Proc. Zoolog. the permanence of virtue on this Soc.’ 1868, p. 409. Chap. IV. Moral Sense. lOI of a troop of monkeys acts as the sentinel, and utters cries expressive both of danger and of safety.® Social animals perform many httle 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 griseo-viridis has rushed through a thorny brake, each monkey stretches itself on a branch, and another monkey sitting by, “conscientiously” examines its fur, and exti-acts every thorn or burr. 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, &c. ; and when they come to a large one, as many as can stand round, turn it over together and shai’e 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 ChiUingham 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 dovoi 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 sui-rounded. 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 away — the dogs being too much astonished to make an attack. I cannot resist giving another scene which was witnessed by this same naturahst ; an eagle seized a young Cercopithecus, which, by clinging to a branch, was not at once carried off; it cried iOudlyfor assistance, upon which the other members of the troop, with much uproar, rushed to the rescue, surrounded the eagle, ®^Biehm, ‘ Thierleben,’ B. i. 1864, the evidence of Alvarez, whose oh- 8. o2, 79. For the case of the serrations Brehm thinks quite trust- monkej^ extracting thorns from worthy. For the cases of the old each other, see s. 54. With respect male baboons attacking the dogs, to the Hamadryas turning over see s. 79 ; and with respect to tlie stones, the fact is given (s. 7 6) on eagle, &. 60. 102 Pabt L The Descent of Man. and pulled out so many feathers, that he no longer thought of his prey, but only how to escape. This eagle, as Brehm remarks, assirredly would never again attack a single monkey of a troop.^“ It is certain that associated animals have a feeling of love for each other, which is not felt by non-social 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,^^ states that his macaws, which lived free in Norfolk, took “ an extravagant interest ” in a pair with a nest ; and when- ever the female left it, she was surrounded by a troop “ scream- “ ing 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 surroimd and stare intently on a dying or dead companion ; ap- parently, however, as Houzeau remai’ks, 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 natm’al 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 theii’ con- duct 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 faU ill, bury them ahve.^ Many animals, however, certainly sympathise with each other’s distress or danger. This is the case even with birds. Capt. Stansbui-y “ found on a salt lake in Utah an old and completely blind pehcan, which was very fat, and must have been well fed for a long time by his companions. Mr. Blyth, as he informs Mr. Belt gives the case of a spider-monkey (Ateles) in Nicara- gua, 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 re- mained 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 Nicaragua,’ 1874, p. 118. " ‘ Annals and Mag. of Nat. Hist.,’ November, 1868, p. 382. Sir J. Lubbock, ‘ Prehistoria Times,’ 2nd edit. p. 446. ” 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 Chap. IV. Moral Sense. 103 me sa-w Indian crows feeding two or thi-ee 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 develop- ment of any special instinct.^ 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 feehng in a dog. 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 httle 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 hck his mistress’s face, and comfort her. Brehm^® 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 httle American monkey. Several years ago a keeper at the Zoological Gardens shewed ma 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, hved 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 his hfe. 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 that dogs possess something very hke a conscience. Dogs possess some power of self-command, and this does not appear to be wholly the result of fear. As Braubach^^ 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 faith- ful to his driver or keeper, and probably considers him as the ” As Mr. Bain states, “effective ‘De I’Espfece et de la Classe,’ “ aid to a sufferer springs from sym- 1869, p. 97. “ pathy proper ‘ Mental and Moral ‘ Die Darwin’sche Art-Lehre,’ Science,’ 1868, p. 245. 1869, s. 5i. “ ‘ Thierlcbcn, B. i. b. 85. 104 The Desce7it of Ma7t. Part L leader of the herd. Dr. Hooker informs mo that an elephant, which he was riding in India, became so deeply bogged that ho 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.^® 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 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 half-wild cattle in S. Africa, says,^ that they cannot endure even a momentary separa- tion 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 self-reliance to accept the position. The men who break in these animals for harness, watch assidu- ously for those who, by grazing apart, shew a self-reliant dis- position, and these they train as fore-oxen. 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 look- out for the individuals which wander from the herd. With respect to the imiralse 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 per- forming 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 shepherd -dog delights in driving and running round a flock of sheep, but not in worrying them ; a young fox-hound delights in hunting a fox, whilst some other kinds of dogs, as I have witnessed, utterly disregard foxes. MTiat See also Hooker’s ‘ Himalayan See his extremely interesting Journals,’ vol. ii., 1854, p. 333. paper on ‘ Gregariousness in Cattle, Brehm, ‘ Thierleben,’ B. i. s. and in Man,’ ‘ ilacmillan’s Mag.’ Feb. 76. 1871, p. 353. Chap. IV. Moral Sense. lOS a strono- feeling of inwai-d satisfaction must impel a bird, so full of acti-dty, 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 self-preservation, and is m 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 pleasui-e or pain may be erro- neous. 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 uncomfort- able 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 oi eating were, no doubt, first acquired in order to induce animals to eat. The feeling of pleasure from soeiety is probably an extension of the parental or filial affections, since the social instiQct seems to be developed by the young remaining for a long time with their parents ; and this extension may be attri- buted 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 gi’eater numbers. With respect to the origin of the parental and filial affections, which apparently lie at the base of the social instincts, we Imow 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 io6 The Descent of Mmi. Pakt I. been with the unusual and opposite feeling of hatred between the nearest relations, as with the worker-bees which kill their brother-drones, and with the queen-bees which kill their "daughter-queens; the desire to destroy theh’ 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 star-fishes 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 all-important 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 en- “ during hunger, cold, fatigue, revives m 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.^ 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 towai-ds known, and more or less beloved members, but not to all the individuals of the same species. This fact is not more sur- prising 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 ** See the first and striking chapter in Adam Smith’s ‘Theory of Moral Sentiments.’ Also Mr. Bain’s ‘ Mental and Moral Science,’ 1868, p. 244, and 275-282. Mr. Bain states, that “ sympathy is, in- “ directly, 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, m.ay make “ up, by sympathy and good officer. “ returned, for all the sacrifice.” But if, as appears to be the case, sympathy is strictly an instinct, its exercise would give direct plea- sure, in the same manner .as the exercise, as before remarked, of al- most every other instinct. Chap. IV. Moral Smse. 107 mankiiid, 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 commu- nities, which included the greatest number of the most sympa- thetic members, would flomish best, and rear the greatest number of offspring. 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 long-continued habit. So remarkable an instinct as the placing sentinels to warn the community of danger, can hardly have been the indhect result of any of these faculties ; it must, there- fore, have been dhectly 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 coui'age, 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 feehng 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 conquer- ing the maternal instinct. The former is wonderfully strong ; a confined bnd 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' io8 The Descent of Man. Pabt I, continue to exist, and thus unintentionally to commit suicide. Every one knows how strong the maternal instinct is, leading even timid birds to face gi’eat danger, though with hesitation, and in opposition to the instinct of self-preservation. Neverthe- less, the migratory instinct is so powerful, that late in the autumn swallows, house-martins, and swifts frequently desert their tender young, leaving them to perish miserably in their nests.^^ 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 force. Man a social animal. — 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 con- finement is one of the severest punishments • which can bo 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 ape-like progenitors of man were likewise social ; but this is not of much importance for us. Although man, as 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 illus- trious 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, thirty- six 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 fliglit, ai'e likewise deserted and left behind. See Blackwall, ‘Researches in Zoo- logy,’ 1834, pp. 108, 118. For some additional evidence, although this is not wanted, see Lerov, ‘ Lettres Phil.’ 1802, p. 217. For Swifts, Gould’s ‘Introduction to the Birds of Great Britain,’ 1823, p. 5. Simi- lar cases have been observed in Canada by Mr. Adams ; ‘ Pe>p. Science Review,’ July 1873, j>. 283. Chap. IV. Moral Sense. 109 lie 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 feehngs ; 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 he 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 self-command. He would from an inherited tendency be willing to defend, in concert with others, his fellow-men ; and would be ready to aid them in any way, which did not too greatly interfere with his own welfare or his own strong desires. 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 stiU. 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 cleai’ly shewn,“^ 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.” Conse- quently man would be influenced in the highest degree by the wishes, approbation, and blame of his fellow-men, 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 ape-like 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 ’’ Hume remarks (‘ An Enquiry- Concerning the Principles of Morals,’ edit, of 1751, p. 132), “There seems “ a necessity fcr confessing that the “ hajipiness and misery of others “ are not spectacles altogether in- dilferent to us. but that the view “ of the former . . . communicates “ a secret joy ; the appearance of “ the latter . . . throws a melan- “ choly damp over the imagina- “ tion.” -* ‘ Mental and Moral Science,’ 1868, p. 254 ilO The Descent of Mem. Pakt 1, of his fellow-men, and unfortunately very often by liis o^\ti strong selfish desires. But as love, sympathy and self-command 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 pleasiu'e or pain, to certain lines of conduct. He might then declare — not that any barbarian or uncultivated man could thus think — I 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. The more enduring Social Instincts conquer the less persistent Instincts. — 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 self-preservation, 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 instinc- tive 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 fellow-creature. Nevertheless many a civilized man, or even boy, who never before risked his life for another, but full of courage and sympathy, has diregarded the instinct of self-preservation, 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 than that of any other instinct or motive; for they are performed too instan- taneously 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 self-preservation 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 mo^al. They Moral Sense. Ill (Jhap. rv. confine this term to actions done deliberately, after a Tictory 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.^® 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,**® 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 quahties 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 aU actions of a certain class as moral, if performed by a moral being. A moral being ite 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 dehberately, after a struggle with opposing “ I refer here to the distinction between what has been called rna- terial and formal morality. I am glad to find that Prof. Hu.xley (‘Cri- tiques and Addresses,’ 1873, p. 287) takes the same view on this subject as I do. Mr. Leslie Stephen re- marks (‘Essays on Freethinking and Plain Speaking,’ 1873, p. 83), “ the “ metaphysical distinction between “ material and formal morality is “ as irrelevant as other such dis- “ tinctions.” 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). II2 The Desceiit of Man. Part L motives, or impulsively through iustinct, or from the effects of slowly-gained habit. But to return to our more immediate subject. Although some instincts are more powerful than others, and thus lead to cor- responding 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 self-preservation, hunger, lust, vengeance, &c. 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. N evertheless 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 danger-signal, 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 desii-e, 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 aiDprobation or disapprobation ; and this all follows from sympathy, a funda- mental 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 natiu’e 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 himger ; 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 pos- session 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.’” Enmity or hatred ueoms also perhaps more so than any other to be a highly persistent feeling, that can be named. Envy is dc- Chap. IV. Moral Sense. 113 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 ever-present 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 aU animals causes dissatisfaction, or even misery. The above case of the swallow affords an illustration, though of a reversed natui-e, 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 con- gregate in flocks. Whilst the mother-bird is feeding, or brooding over her nestlings, the maternal instinct is probably stronger than the migratory ; but the instinct which is the more persis- tent 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 the bleak north from cold and hunger. fined as hatred of another for some excellence or success; and B.icon insists (Essay ix.), ‘‘ Of all other ■“ affections envy is the most im- “ portiine 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 inn.ate, and is certainly a most per- sistent one. It seems to be the complement and converse of the true social instinct, from what v/e 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 ho had done him an injury and had become his enemy. Nor is it pro- bable that the primitive conscience would reproach a man for injuring his enemy : rather it would re- proach 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 in- stincts, together with sympathy, should have been highly cultivated and extended by the aid of reason, instruction, and the love or fear of God, before any such golden rule would ever be thought of and obeyed. I The Descent of Man. Pae:: I 1 14 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 ever-enduring 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 future. 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 shght regret or repentance may be explained by the view advocated in this chapter, it is impossible thus to account for the soul-shaking 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. Eemorse 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 noisery, 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 ELindoo, 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,^® that a native on his farm, after losing one of his wives from disease, came and said that “ he was ” ‘ Insanity in Relation to Law;’ Ontario, United States, 1871, p. 14, Chav. IV. Moral Sense. 115 “ going to a distant tribe to spear a -woman, to satisfy bis sense “ of duty to bis wife. I told bim that if be did so, I would “ send bim to prison for life. He remained about tbe farm for “ some months, but got exceedingly thin, and complained that “ be could not rest or eat, that his -wife’s spirit was haunting “ bim, because be had not taken a bfe for hers. I was in- “ exorable, and assured bim that nothing should save bim if be “ did.” Nevertheless tbe man disappeared for more than a year, and then returned in high condition ; and bis other -wife told Dr. Landor that her husband bad taken the life of a woman belonging to a distant tribe; but it was impossible to obtain legal evidence of tbe act. Tbe breach of a rule held sacred by tbe tribe, will thus, as it seems, give rise to tbe deepest feelings, —and this quite apart from tbe social instincts, excepting in so far as tbe rule is grounded on tbe judgment of tbe community. How so many strange superstitions have arisen throughout tbe world we know not ; nor can we tell bow some real and great crimes, such as incest, have come to be held in an abhorrence (which is not however quite universal) by tbe 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 tbe 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 o-wn, an answer just opposite to oui’s would be given without hesitation.”*® We may, therefore, reject the belief, lately insisted on by some Avriters, that the abhorrence of incest is due to our possessing a special God -implanted con- science. 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 delivering himself up to justice. Man prompted by his conscience, will through long habit acquire such perfect self-command, that his desires and passions will at last yield instantly and without a struggle to his social s^pathies and instincts, including his feeling for the judgment of his fellows. The stiU hungry, or the stiU revengeful man will not thmk of stealing food, or of wreaking his vengeance. It is possible or as we shall hereafter see, even probable, that the habit of self- command may, like other habits, be inherited. Thus at last man * E. B. Tylor in ‘ Contemporary Revievr,’ April, 1873, p. 707. I 2 ii6 The Descent of Man. Paet L comes to feel, througli acquired and perhaps inherited habit, that it is best for him to obey liis more persistent impulses. The imperious word ought seems merely to imply tho 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 fail in their duty and act wrongly. 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 tho time strong, and when recalled are not over-mastered by the persistent social instincts, and the judgment of others, then he is essentially a bad man ; “ and the sole restraining motive left is the fear of punishment, and the conviction that in the long run it would be best for his own selfish interests to regard the good of others rather than his own. It is obvious that every one may with an easy conscience gi’atify 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 self-reproach, or at least of anxiety, it is almost neces- sary for him to avoid the disapprobation, whether reasonable or not, of his fellow-men. 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 hkewise 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 additional fear of divine punishment often sui>ervenes. The strictly Social Virtues at first alone regarded. — Tho 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. Tho virtues which must bo practised, at least generally, by rude men, so “ Dr. Prosper Despine, in his many curious cases of the worst ‘ Psychologic Naturelle,’ 1868 (tom. criminals, who apparently have been i. p. 243 ; tom. ii. p. 169) gives entirely destitute of conscience. Moral Sense. 117 Cha;’. IV. that they may associate in a body, are those which are still rcco0 ‘ Origin of Species,’ 5th edit. 1869, p. 194. ‘The Variation of Animals and Plants under Domesti- cation,’ vol. ii. 1868, p. 348. ' ‘ ‘ An Introduction to the CTassi- fication of Animals,’ 1869, p. 99. Chap. YI. Affinities and Genealogy. 153 ao'es 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 Sub-family, 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 strongly-marked dif- ferences in some few points, — that is, to the amount of modifi- cation undergone ; and how much to close resemblance in munerous 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 resemblances, as giving a truly natural classification. In forming a judgment on this head with reference to man, we must glance at the classification of the Simiadte. This family is divided by almost all naturalists into the Catarhine 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 Platyrhine 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 Catarhine or Old World division ; nor does he resemble the Platyrhines more closely than the Catarhines 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 man-hke 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 off-shoot from the Old World Simian stem ; and that under a genealogical point of view, he must be classed with the Catarhine division.^^ The anthropomorphous apes, namely the gorilla, chimpanzee. This is nearly the same classifi- adaj which answer to the Catarhines, cation as that provisionally adopted the Cebidoe, and the Hapalida;, — by Mr. St. George Mivart (‘Tran- these two latter groups answering sact. Philosoph. Soc.’ 1867, p. 300), to the Platyrhines. Mr. Mivart who, after separating the Lemurida:, still abides by the same view; see divides the remainder of the Pri- ‘ Nature,’ 1871, p. 481, mates into the Hominida:, the Simi- 154 The Descent of Man. Past I. oraug, and hylobates, are by most naturalists separated from the other Old World monkeys, as a distinct sub-group. I am aware that Gratiolet, relying on the structure of the brain, does not admit the existence of this sub-group, and no doubt it is a broken one. Thus the orang, as lilr. St. G. Mivart remarks,^ “ is one of the “ most peculiar and aberrant forms to be found in the Order.” The remaining non-anthropomorphous Old World monkeys, are again divided by some naturalists into two or three smaller sub- groups ; the genus Semnopithecus, with its peculiar sacculated stomach, being the type of one such sub-group. But it appears from M. Gaudiy’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 higher gi’oups were once blended together. If the anthropomorphous apes be admitted to form a natural sub-group, then as man agrees with them, not only in all those characters which he possesses in common with the whole Catarhine 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 sul>group gave birth to man. It is not probable that, through the law of analogous variation, a member of one of the other lower sub-groups should have given rise to a man-hke 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.”” Every naturalist, who believes in the principle of evolution, will grant that the two main divisions of the Simiadse, namely the Catarhine and Platyrhine monkeys, with their sub-groups, 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 stiU have formed a single natural group ; but some of the species or incipient genera would have aheady begun to indicate by their diverging characters the future distinctive marks of the Catarhine and Platyrhine divisions. Hence the members of this supposed ancient group would not have been so uniform in their den- tition, or in the structure of their nostrils, as are the existing ‘ Transact. Zoolog. Soc.’ vol. vi. ” Mr. St. G. Mivart, ‘Transact. 1867 P *^14. Phil. Soc.’ 1867, p. 410, Chap. VI. A ffinities and Genealogy. 155 Catarhine monkeys in one way and the Platyrhines in another way, but would have resembled in this respect the allied Lemu- ridsc, which differ greatly from each other in the form of their muzzles,’*' and to an extraordinary degree in their dentition. The Catarhine and Platyrhine 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 Catarhine and Platyrhine monkeys, other characters in an intermediate con- dition, and some few, perhaps, distinct from those now found in either group. And as man from a genealogical point of view belongs to the Catarhine or Old World stock, we must conclude, however much the conclusion may revolt our pride, that om* early progenitors would have been properly thus designated.’® But we must not fall into the error of supposing that the early progenitor of the whole Simian stock, including man, was iden- tical with, or even closely resembled, any existing ape or monkey. On the Birthplace and Antiquity of Man. — We are naturally led to enquire, where was the birthplace of man at that stage of descent when our progenitors diverged from the Catarhine 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 in- habited by extinct apes closely allied to the gorilla and chim- panzee ; 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 sx>eculate on this subject ; for two or three anthropomorphous apes, one the Diyopithecus ” of Lartet, nearly as large as a man. Messrs. Murie and Mivart on the Lerauroidea, ‘Transact. Zoolog. Soc.’ vol. vii. 1869, p. 5. ** Ililckel has come to this same conclusion. See ‘ Ueber die Ent- stehnng des Menschengeschlechts,’ in Virchow’s ‘ Samnilung. gemein. wissen. Vortruge,’ 1868, s. 61. Also his ‘ NatUrliche Schopfungsge- schichte,’ 1868, in which he gives in detail his views on the genealogy of man. ” Dr. C. Forsyth Major, ‘ Sur les Singes Fossiles trouvds en Italie : ‘ Soc. Itnl. des Sc. Nat.’ tom. xv. 1872 The Descent of Man. Paet I. 156 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 for migration on the largest scale. At the period and place, whenever and wherever it was, when man first lost his hau-y covering, he probably inhabited a hot country ; a circumstance favomable 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 Catarhine 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 co-descendants 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 amorint of modification in certain characters in comparison with the higher apes. 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 allies — between the Tarsius and the other Lemuridse — between 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 cenUiries, the civilised races of man will almost certainly exterminate, and replace, the savage races throughout the world. At the same time the anthro- pomorphous apes, as Professor Schaafifhausen has remarked,*® 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 Australian and the gorilla. *® ‘ Anthropological Review,’ April, 18G7, p. 236. Chap. VI. A ffinities and Genealogy. 157 With respect to the absence of fossil remains, serving to sonnect man with his ape-like progenitors, no one will lay much stress on this fact who reads Sir C. LyelFs discussion,^® 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 yet been searched by geologists. Lovjer Stages in the Genealogy of Man. — We have seen that pi an appears to have diverged from the Catarhine 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 Hackel 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 well-stocked continents. This group Likewise presents many gradations, leading, as Huxley remarks,®® “ 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 Simiadse were originally developed from the progenitors of the existing Lemm’idm ; and these in their turn from forms standing very low in the mammalian series. 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 exiRtiug Mar- supials, but from their early progenitors. The Monotremata are plainly allied to the Marsupials, forming a third and still lower ’• ‘Elements of Geology,’ 1865, pp. 583-585. ‘ Antiquity of Man,’ 105. 1863, p. 145. ” ‘Man’s Place in Nature,’ p. 158 The Descent of Man. Pabt I division in tlie 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 circum- stances. 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 Une of descent. He who wishes to see what ingenuity and knowledge can effect, may consult Prof. Hackel’s works.^‘ 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 fish- like animal. The belief that animals so distinct as a monkey, an elephant, a humming-bird, a snake, a frog, and a fish, &c., could all have sprung from the same parents, will appear monstrous to those who have not attended to the recent progress of natural lustory. Eor this belief implies the former existence of links binding closely together all these forms, now so utterly unlike. 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 bhds— the birds referred to being the ostrich-tribe (itself evidently a widely-diffused remnant of a larger group) and the Archeopteryx, that strange Secondary bird, with a long lizard-like tail. Again, according to Elaborate t.ables 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 dis- cussed by Hilckel, although he diflci's on some points. He expresses, also, his high estimate of the general tenor and spirit of the whole work. Pala:ontology,’ 1860, p. 199, Chap. YI. A ffi,7iities and Ge7iealogy. 159 Prof. Owen,^ the Tchthyosaurians — great sea-lizards furnished with paddles— present 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 great waters of the ocean in the same way that islands are to continents. 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 Hackel 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, &c. ; 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 Molluscoida of Huxley — a lower division of the great kingdom of the MoUusca ; but they have recently been placed by some naturalists amongst the Vermes or worms. Their larvrn some- what resemble tadpoles in shape,^® and have the power of swimming freely about. M. Kovalevsky ^ has lately observed that the larvcB 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 ** At the Falldaud Islands I had the satisfaction of seeing, in April 1833, and therefore some years be- fore any other naturalist, the loco- motive larva: of a compound Asci- dian, closely allied to Synoiciim, but apparently generically distinct from it. The tail was about five times as long as the oblong head, and terminated in a very fine fila- ment. It was, as sketched by me under a simple microscope, plainly divided by transverse opaque parti- tions, which I presume represent the great cells figured by Kovalev- sky. At an early stage of develop- ment the tail was closely coiled round the head of the larva. ‘ M^moires do I’Acad. fins Sciences fie St. Pe'tersbourg,’ t om. x. No. 15, 1866. i6o The Descent of Man. Paut I, 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.^® We should then bo justified in believing that at an extremely remote period a group of animals existed, resembling in many respects the larvm of our present Ascidians, which diverged into two great branches — the one retrograding in development and producing the present class of Ascidians, the other rising to the crown and summit of the animal kiagdom by giving birth to the Vertebrata. We have thus far endeavoured rudely to trace the genealogj- of the Vertebrata by the aid of their mutual affinities. We will now look to man as he exists ; and we shall, I think, bQ 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, to which I shall here allude, have been given in the previous chapters. 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 pro- vided 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 Quadru- mana. At this or some earlier period, the great artery and nerve of the humerus ran through a supra-condyloid foramen. The intestine gave forth a much larger- diverticulum or csecum 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, forest-clad land. The males had gi'eat canine teeth, which 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 Exp^rimentalc,’ for 1872. Nevertheless, this naturalist re- marks, p. 281, “ L’organisation de la “ larve ascidienne en dehors de “ toute hypothfese et de toutetheorie, “ nous montre comment la nature “ peut produire la disposition fonda- “ mentale du type vertebre (I’ex- “ istence d’une corde dorsale) chez “ un inverWbrd par la seule con- “ dition vitale de I’adaptation, “ et cette simple possibility du “ passage supprime I’abimo entre “ ies deux sous-r6gnes, encore bicn “ qu’en ignore par oil le passage “ s’est fait en ryality.” Chap. YI. Affinities and Genealogy. i6r 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 mem- brane. At a still earl ier period the progenitors of man must have been aquatic in their habits; for morphology plainly tells us that our lungs consist of a modified swim-bladder, which once served • as a float. The clefts on the neck in the embryo of man show where the branchi® once existed. In the lunar or weekly re- current 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 wolfBana. 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 amphioxus. 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 re- productive 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 hermaphi’odite or androgynous.^® But here we encounter a singular difficulty. In the mammalian class the males possess rudiments of a uterus with the adjacent passage, in their vesiculse prostaticse; they bear also rudiments of mammae, and some male Marsupials have traces of a marsupial sack.^ Other analogous facts could be added. Are we, then, to suppose that some extremely ancient mammal continued andro- gynous, 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.^® That various accessory parts. This is the conclusion of Prof. Gegenhaur, one of the highest au- thorities 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 org.ans of even “the higher verte- “ brata are, in their early condition, “ hermaphrodite.” Similar views have long been held by some authors, though until recently without a firm basis. The male Thylacinus offers the best instance. Owen, ‘ Anatomy of Vertebrates,’ vol. iii. p. 771. Hermaphroditism has been ob- served in several species of SeiTanus, as well as in some other fishes, M The Descc7it of Man. Taut L 162 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 bh’ds, 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 milk-secreting 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 milk-secreting 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 KolUker 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 indi- vidual generally represents and accords with the development of successive beings in the same line of descent. The Marsupials difier 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.^® 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 mammjB ? It is possible that they were first developed in the females and then transferred to the males; but from what follows this is hardly probable. where it is either normal and sym- metrical, or abnormal and uni- lateral. Dr. Zouteveen has given me references on this subject, more especially to a paper by Prof. Hal- bertsma, in the ‘Transact, of the Dutch Acad, of Sciences,’ vol. xvi. Dr. Giinther doubts the foot, but it has now been recorded by too many good observers to be any longer disputed. Dr. M. Lcssona writes to mo, that ho has veri- fied the observations made _ by Cavolini on Serranus. Prof. Krco- lani has recently shewn (‘Accad. delle Scienze,’ Bologna, Dec. 28, 1871) that eels are androgynous. Prof. Gegenbaur has shewn (‘ Jenaische Zcitschrift,’ 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 hlarsupials, and tlie latter from those of the Mnnotre- niata. Sec, also, a memoir by Dr. Max Huss, on the mammary glands, ibid. B. viii. p. 176. Chap. VI. Affinities and Genealogy. 163 It may be suggested, as another view, tliat 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 ; 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 o\ra 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 the 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 mammai'y 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 sympa- thetically 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 dui’ing 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,®* 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 well-known principles of inheritance, this state of inactivity would probably be transmitted to the males at the con-esponding ago of maturity. But at an earlier age these 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 An.at. and Phys.’ Nov. 1, 1866, p. 78. Dr. Gunther has likewise de- scribed similar cases. Madlla. C. Iloyer has suggested a similar view in her ‘Origine da ITIomme,’ &c., 1870. M 2 164 The Descent of Man. Paet I, organs would be left unaffected, so that they would be almost equally well developed in the young of both sexes. Conclusion. — 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 matuiity, as I should be inclined to add. Now as organisms have become slowly adapted to diver- sified 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 organisa- tion 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 gi-oups of organic beings are always supplanted, and dis- appear as soon as they have given birth to other and more perfect gi-oups. The latter, though victorious over their pre- decessors, 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 lowly-organised group as jjerfect representatives of their ancient predecessors. 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,®'^ resembling the larvm of existing Ascidians. These animals probably gave rise to a The inhabitants of tlie sea- shore must be greatly affected by the tides ; animals living either about the mean high-water mark, or about the moan low-water mark, pass through a complete cycle of tidal changes in a fortnight. Con- •sequently, their food supply will undergo marked changes week by week. The vital functions of such animals, living under these con- ditions 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 ns in other classes, many nor- mal and abnormal processes have one or more whole weeks as their periods ; this would be rendered intelligible if the Vertebrata are de- scended fiom an animal allied to Chap. YI. Affinities and Genealogy, i6s group of fishes, as lowly organised as the laucelet ; 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 degi'ee. But no one can at present say by what line of descent the three higher and related classes, namely, mammals, bhds, 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 Lemmudse ; and the interval is not very wide from these to the Simiad®. The Simiad® 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 jareparing for the advent of man : and this, in one sense is strictly true, for he owes his bhth 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 marvellous structure and properties. the existing tidal Ascidians. Many instances of such periodic processes might be given, as the gestation of mammals, the duration of fevers, &c. 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 pro- cess or function, would not, when once gained, be liable to change; consequently it might be thus trans- mitted 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 gesta- tion in each mammal, and the hatching of each bird’s eggs, and many other vital processes, thus betray to us the primordial birth- jilace of these animals. 1 66 The Descejit of Man. Part I, CHAPTER YII. On the Races of Man. The nature and value of specific characters — Application to the races of man — Arguments in favour of, and opposed to, ranking the so-called races of man as distinct species — Sub-species — Monogenists and poly- genists — Convergence of character — Numerous points of resemblance in body and mind between the most distinct races of man — The state of man when he first spread over the earth — Each race not descended from a single pair — The extinction of races — The formation ot races — ^The effects of crossing — Slight influence of the direct action of the con- ditions of life — Slight or no influence of natural selection — Sexual selection. It is not my intention here to describe the several so-caUed races of men ; but I am about to enquire what is the value of the dif- ferences between them under a classificatory point of view, and how they have originated. In determining whether two or more alhed 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 naturahsts. 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 treatiog them as species. Even a shght 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 sterility, or in the case of animals of some mutual repugnance to pairing. Independently of fusion from intercrossing, the complete absence, in a well-investigated 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 bo liighly variable and yet not yield intermediate varieties. Gcogi-aphical distribution is often brought into i)lay unconsciously and sometimes consciously ; so that forms living in two widely separated areas, in which most Chap. VII. The Races of Man. 167 of the other inhabitants are specifically distinct^ are themselves usually looked at as distinct ; but in truth this aflbrds no aid in dis- tinguishing geogi’aphical races from so-called good or true species. Now let us apply these generally-admitted 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 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 sup- posed ; certain negro tribes must be excepted, whilst others, as Dr. Eohlfs 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 Antliropologique 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. Neverthe- less, 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 slight differences in the features, and by expression. There is, however, no doubt that the various races, when cai’efully compared and measured, differ much from each other, — as in the textui’e of the hair, the relative proportions of all parts of the body,*^ the capacity of the lungs, the form and capacity of the skull, and even in the convolutions of the brain.® But it would bo an endless task to specify the numerous points of difierence. 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 * ‘History of India,’ 1841, vol. i. p. 323. Father Ripa makes exactly the same remark with respect to the Chinese. * A vast number of measnre- menU of Whites, Blacks, and In- dians, are given in the ‘Investiga- tions in the Military and Anthropo- log. Statistics of American Soldiers,’ by B. A. Gould, 1869, pp. 298-358 ; ‘ 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. Schwai'z, in the ‘ Reise der Novara: Anthropolog. Theil,’ 1867. ® See, for instance, Mr. Marshall’s account of the brain of a Bush- woman, in ‘Phil. Transact.’ 1864, p. 519. The Descent of Man. Part I. 1 68 struck with the contrast between the taciturn, even morose, aborigines of S. America and the light-hearted, talkative negroes. There is a nearly similar contrast between the Malays and tlw Papuans,^ who hve under the same physical conditions, and ar 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, Austrahan, or Mongolian, were to compare them, he would at once perceive that they differed in a multitude of characters, some of shght and some of considerable importance. On enquiry he would f.nd that they were adapted to live under widely different climates, and that they differed somewhat in bodily constitution and mental dis- position. 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.® He would also hear, on the authority of an excellent observer. Dr. Lund,® that the human skulls found in the caves of Brazil, entombed with many extinct mammals, belonged to the same type as that now pre- vailing throughout the American Continent. ^ Wallace, ‘ The Malay Archi- pelago,’ vol. ii. 1869, p. 178. * With respect to the figures ia the famous Egyptian caves of Abou- Simbel, M. Pouchet says (‘ The Plurality of the Human Races,’ Eng. translat. 1864, p. 50), that he was far from finding recognisable repre- sentations 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 de- gree 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 ; where- as 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 in- formed by Mr. Birch), insists in the strongest manner that he is identical in character with the Jews of Ant- werp. 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 strongly marked negro type of features ; but Messrs. Nott and Gliddon (ibid. p. 146, fig. 53) de- scribe him as a hybrid, but not of “ negro intermixture.” “ As quoted by Nott and Gliddon, ‘Types of Mankind,’ 1854, p. 439. They give also corroborative evi- dence ; but C. Vogt thinks that the subject requires further investiga- tion. Chap. Vll. The Races of Man. 169 Our naturalist would then perhaps turn to geographical dis- tribution, and he would probably declare that those forms must be distinct species, which differ not only in appearance, but ai-e fitted for hot, as well as damp or dry countries, and for the Arctic regions. He might appeal to the fact that no species in the group next to man, namely the Quadi’umana, 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 matm-ity, even under the temperate chmate of Europe. He would be deeply impressed with the fact, first noticed by Agassiz,' that the different races of man are distributed over the world in the same zoological proviuces, 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 well-marked manner with the Hottentots; but plainly with the Papuans and Malays, who are separated, as Mr. Wallace has shewn, by nearly the same hne 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 members of his class. In determining whether the supposed varieties of the same kind of domestic animal should be ranked as such, or as spe- cifically distinct, that is, whether any of them are descended from distinct wild species, every natiualist would lay much stress on the fact of their external parasites being specifically distinct. AH 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 ’ ‘ Diversity of Origin of the Human Races,’ in the ‘ Christian Examiner,’ July 1850. 170 The Descent of Man. Past I. countries from the different races of man ; ® 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 Sandvnch 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 hce. 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 shght 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 bo specifically distinct, might fairly be urged as an argument that the races themselves ought to be classed as distinct species. 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* 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 half-castes are killed by the pure blacks : and an account has lately been published of eleven half- caste youths murdered and burnt at the same time, whose remains were foimd by the pohce.“ Again, it has often been said that when mulattoes- intermarry they produce few children ; on the other hand. Dr. Bachman of Charleston” positively * ‘ Traus.ict. R. Soc. of Edinburgh,’ vol. xxii. 1861, p. 567. “ ‘ On the Phenomena of Hybridity in the Genus Homo,’ Eng. translat. 1864. '» See the interesting letter by Mr. T. A. Murray, in the ‘ Anthro- )iolog. Review,’ April 1868, p. liii. lu 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 Scicntifiques,’ March 1869, p. 239) much evidence that Australians and Europeans are not sterile when crossed. ” ‘ An Examination of Prof. Agassiz’s Sketch of the Nat. Pro* Chap. VII. 171 The Races of Man. asserts that lie has known mulatto families which have inter- married for several generations, and have continued on an average as fertile as either pmn whites or pure blacks. Enquiries formerly made by Sir C. Lyell on this subject led him, as he ioforms me, to the same conclusion.^ In the United States the census for the year 1854 included, according to Dr. Bachman, 405,751 mulattoes ; and this nmnber, considering all the circum- stances 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 amomit of absorption of mulattoes into negroes must always be in progioss; and this would lead to an apparent diminution of the former. The inferior vitality of mulattoes is spoken of in a trustworthy work*® as a well-known phenomenon ; and this, although a different considera- tion fi’om their lessened fertility, may perhaps be advanced as a proof of the specific distinctness of the pai’ent 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 imder the category of extremely distinct species. The common Mule, so notorious for long life and vigour, and yet so sterile, shews how little necessary con- nection there is in hybrids between lessened fertility and vitality ; other analogous cases could be cited. Even if it should hereafter bo 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 inter-broeding, 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 vinces of the Animal World,’ Charles- ton, 1855, p. 44. 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 Heade informs jne 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. ‘ Military and Anthropolog. Statistics of American Soldiers,’ by B. A. Gould, 1869, p. 319. 1/2 The Descent of Man. Paut I. 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 PaUasian docti’ine,^* that domestication tends to eliminate the sterility which is so general a result of the crossing of species in a state of nature. Prom these several considerations, it may be justly urged that the perfect fertility of the intercrossed races of man, if established, would not absolutely preclude us from ranking them as distinct species. Independently of fertility, the characters presented by the off- spring from a cross have been thought to indicate whether or not the parent-forms ought to be ranked as species or varieties ; but after carefully studying the evidence, I have come to the con- clusion that no general rules of this kind can be trusted. The ordinary result of a cross is the production of a blended or ‘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 specially- acquired quality, but, like the in- capacity of certain trees to be graft- ed togethex', is incidental on other acquired differences. The natui'e of these differences is imknown, but they relate more especially to the re- productive system, and much less so to external structure or to ordinary diffei'ences in constitution. One important element in the sterility of crossed species appai’ently lies in one or both having been long habi- tuated to fixed conditions ; for we know that changed conditions have a special influence on the repro- ductive system, and we have good reason to believe (as before re- mai’ked) that the fluctuating con- ditions of domestication tend to eliminate that sterility which is so general with species, in a natural state, when crossed. It has else- where been shewn by me (ibid. vol. ii. p. 185, and ‘Origin of Species’ 5th edit. p. 317), that the sterility of ci'ossed species has not been ac- quix'od through natural selection : we can see that when two forms have already been rendered very sterile, it is scarcely possible that their steidlity should be augmented by the preservation or survival of the more and more steidle indi- viduals; for as the sterility in- creases, fewer and fewer offspring will be produced from which to bi'eed, and at last only single in- dividuals will be pi’oduced, at the rarest intervals. But there is even a higher gi'ade 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 pro- duce a single seed, but yet are affected by the pollen of the other species, as shewn by the swelling of the germen. It is hei'e mani- festly impossible to select the more stei’ile individuals, which have al- ready ceased to yield seeds ; so that the acme of sterility, when the germen alone is aflected, cannot liave been gained through selection. This acme, and no doubt the other grades of sterility, are the incidental results of certain unknown differ- ences in the constitution of the re- productive system of the spccice which are crossed. Chap. VII. 173 The Races of Ma7i. intermediate form ; but in certain cases some of the offspring take closely after one parent-form, 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.^® I refer to this point, because Dr. Eohlfs 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 appearance. AVe have now seen that a naturalist might feel himself fuUy 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 wiU have been struck with the disti-ibution of the several so-called 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, and even if proved would not be an absolute proof of then- specific identity. 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 popu- lation consisting of Indians and Spaniards blended in various degrees.'® In many parts of the same continent he would meet with the most complex crosses between Negroes, Indians, and Em-opeans ; 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 ‘The Variation of Animals,’ success and energy of the Paulistas &c., vol. ii. p. 92. in Brazil, who are a much crossed M. de Quatrefages has given race of Portuguese and Indians, with (‘ Anthrojwlog. Review,’ Jan. 1869, a mixture of the blood of other p. 22) an interesting account of the races. 174 The Descent of Man. Part I. crossed in all degrees. Many analogous cases could bo be adaed ; for instance, in Africa. Hence the races of man are not suf- ficiently distinct to inhabit the same country without fusion ; and the absence of fusion affords the usual and best test of specific distinctness. Om- 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 colotu to a certain degree, and the shape of the features gi’eatly, in the Negroes of Africa. The shape of the skull varies much in some races and so it is with every other character. Now all natiualists have learnt by dearly-bought experience, how rash it is to attempt to define species by the aid of inconstant characters. But the most weighty of all the arguments against treating the races of man as distinct species, is that they gi-aduate into each other, independently in many cases, as far as we can judge, of their having intercrossed. Man has been studied more carefuUy 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), twenty-two (Morton), sixty (Crawfurd), or as sixty-three, according to Burke.*® 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 For instance with the abori- gines of America and Australia. Prof. Huxley says (‘ Transact. Inter- nat. 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,” &c. ** See a good discussion on this subject in Waitz, ‘ Introduct. to Anthropology,’ Eng. translat. 1863, pp. 198-208, 227. I have taken some of the above statements from H. Tuttle’s ‘ Origin and Antiquity of Physiail Man,’ Boston, 1866, p. 36. Ch^p. VII. The Races of Man. 175 other, and that it is hardly possible to discover clear distinctive characters between them. Every naturalist who has had the misfortune to undertake the description of a group of highly varying organisms, has en- countered 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 detennined 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 king- dom,'® which we cannot avoid naming as species, but which are connected together by numberless gradations, independently of intercrossing. Some naturalists have lately employed the term " sub-species” 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 diffi- culties on the other side in defining them, it seems that the term “ sub-species ” 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-alhed 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 Prof. Ndgeli has carefully de- has made an.alogous remarks on smbed several striking cases in his some intermediate forms in the ‘ Botanische Mittheilungen,’ B. ii. Compos>ta2 of N. Ameriai. 1866, 8. 294—369, Prof. Asa Gray 176 The Descent of Man, Paet I. can generally be arranged in little groups round other species, like satellites round planets.*® 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 as 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 never-ending doubts whether many closely-allied 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 from the nearest continent. 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 ex- pressing their amount of difference.*^ 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 aU 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 ‘ Origin of Species,’ 5th edit, in the ‘ Fortnightly Review,’ 1865, p. 68. p. 275. See Prof. Huxley to this effect Chap. VII. The Races of Man 177 from a common stock, the differences between the races and their mimber must have been small; consequently as far as their distinguishing characters are concerned, they then had less claim to raii as distinct species than the existing so-caUed 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 present, and had not gi-aduated into each other. 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,^^ they converged in character. When man selects the off- spring 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,^ 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 sub-group ; 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 brain- characters, 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 resem- blances. It would, however, be extremely rash to attribute to convergence close similarity of character in many points of structm-e amongst the modified descendants of widely distinct beings. The form of a crystal is determined solely by the mole- cular 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 physicial condi- ** ‘ Lectures on Mqn,’ Eng. trans- schiohto, &c., Schweineschadel,’ lat. 1864, p. 468. 1864, s. 104. With respect to cattle, * ‘ Die Racen des Schweines,’ see M. de Quatrefages, ‘ (Jnitd dt 1860, 8. 46. ‘ Vorstudien fUr Ge- I’Espfcce Humaine,’ 1861, p. 119 The Descent of Man. Part I. 178 tions, and Btill more on the surrounding organisms which com- pete with each, — and lastly, on inheritance (in itself a fluctuating element) from innumerable progenitors, all of which have liad their forms determined through equally complex relations. It appears incredible that the modified descendants of two organ- isms, 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, evi- dence 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 goriUa, it can hardly be doubted that marked differences in the structure of certain bones would still be discoverable in man as he now exists. Although the existing races of man differ in many respects, as in colour, hair, shape of skull, proportions of the body, &c., 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 inde- pendently 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 Emopeans 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 Euegians on board the " Beagle,” with tlie many little traits of character, shewing how similar their minds were to ours ; and so it was with a full-blooded negro with whom I happened once to be intimate. He who will read Mr. Tylor’s and Sir J. Lubbock’s interesting works 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 aU take in dancing, rude music, acting, painting, tattooing, and otherwise decorating themselves ; in their mutual comprehension of gesture- language, by the same expression in their featm-es, and by the same inarticulate cries, when excited by the siune emotions. This similarity, or rather identity, is striking, when contrasted Tylor’s ‘ Early History of Man- language, see p. 54. Lubbock’s kind,’ 1865 : with respect to gesture- ‘ Prehistoric Times,’ 2nd edit. 1869. Chap. Vll. The Races of Man. 179 ■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 do'wn from any common progenitor of mankind, yet as Westropp and Nilsson have remarked/® the stone arrow-heads, 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 with respect to certain widely-prevalent ornaments, such as zig- zags, &c. ; and with respect to various simple beliefs and cus- toms, such as the burying of the dead under megahthic struc- tures. I remember observing in South America,’*’ 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 remarkable event, or for burying their dead. Now when naturalists observe a close agreement in numerous small details of habits, tastes, and dispositions between two or more domestic races, or between nearly-allied 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 races of man. As it is improbable that the numerous and unimportant points of resemblance between the several races of man in bodily struc- ture 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, pre- ceded 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 birth-place; I for if once learnt they would never have been forgotten.’® He ‘On Analogous Forms of Im- plements,’ in ‘ Memoirs of Anthropo- log. Soc.,’ by H. M. Westropp. ‘ The Primitive Inhabitants of Scandi- navia,’ Eng. translat. edited by Sir J. Lubbock, 1868, p. 104. Westropp, ‘ On Cromlechs,’ &c.. ‘Journal of Ethnological Soc.’ as given in ‘Scientific Opinion,’ June 2nd, 1869, p. 3. ‘Journal of Researches : Vovago of the “ Beagle,” ’ p. 46. ‘Prehistoric Times,’ 1869, p 574. The Descent of Man. i8o Part L tliTis shews that “ the spear, which is but a development of the " knife-point, 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 kno^vn to the ancient cave- inhabitants 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 oui* 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 struggle for Life, as proved by his early and wide diffusion. Prom 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 highly-developed tongues. With- out 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 an early period. 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 ape-like creature to man as he now exists, it would be impossible to fix on any definite point when 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 so-called races of man are thus designated, or are ranked as species or sub-species ; but the latter term apjjears the more appropriate. Finally, we may conclude that when the principle of evolution is generally accepted, as it surely will lie before long, the dispute between the monogcnists and the poly- genists will die a silent and unobserved death. One other question ought not to bo passed over without notice, namely, whether, as is sometimes assumed, each sub-species or race of man has sprung from a single pair of progenitors. With Chap. VII. The Extinction of Races. i8i our domestic animals a new race can readily be formed by care- fully 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 in- dividuals 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 sub-breeds 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 retiun. On the Extinction of the Races of Man. — The partial or complete extinction of many races and sub-races 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 Schaaffhausen,^" “ 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, tliough 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 ® Translation in ‘ Anthropologicai Review,’ Oct. 1868, p. 431 Pakt I. 1 82 The Descent of Man. “ different from any other, ancient or modern, that we have ever "heard of.”* It differed, therefore, from the quaternary race of the caverns of Belgium. Man can long resist conditions which appear extremely un- favourable for his existence.*^ 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 with- out the protection of clothes, or of any building worthy to bo called a hovel. In South Africa the aborigmes 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 shores of tropical Africa. 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 trihe, — such as periodical famines, nomadic habits and the consequent deaths of infants, prolonged suckling, wars, accidents, sickness, licen- tiousness, the stealing of women, infanticide, and especially lessened fertility. If any one of these checks increases in power, even slightly, the trihe 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.* 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 and so it may be with the evil effects from spirituous liquors, as well as with the unconquerably strong taste for them shoAvn by so many ‘ Transact. Intemat. Congress terben der Naturvblker,’ 1868, s. 82. of Prehistoric Arch,’ 1868, pp. 172- Gerland (ibid. s. 12) gives facts 175. See also Broca (translation) in support of this statement, in ‘Anthropological Review,’ Oct. ’’ See remarks to this effect in 1868, p. 410. Sir H. Holland’s ‘ Medical Notes and Dr. Gerland ‘ Ueber das Auss- Reflections,’ 1839, p. 390. Chap. "VII. The Extinction of Races. 183 savages. It farther appears, mysterious as is the fad that the first meeting of distinct and separated people generates disease.®^ 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.”’® 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 •Ml- Bagehot has remarked, that savages did not formerly waste away before the classical nations, as they now do before modem 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.’® The most po- tent of all the causes of extinction, appears in many cases to be lessened fertility and fll-health, 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 flrst 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,’^ who were iu 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 forty-seven adult males, forty-eight adult females, and sixteen children, or in all of 111 souls. In 1835 only one hundred were left. I have collected (‘Journal of Researches, Voyage of the “ Beagle,” ’ p. 435) a good many cases bearing on this subject ; see also Gcrland, ibid. s. 8. Poeppig speaks of the “ breath of civilisation as poisonous “ to savages.” Sproat, ‘ Scenes and Studies ol Savage Life,’ 1868, p. 284. Bagehot, ‘ Physics and Poli- tics,’ ‘ Fortnightly Review,’ April 1, 1868, p. 455. All the statements here given are taken from ‘The last of the Tasmanians,’ by J. Bonwick, 1870. 184 The Descent of Man. Paht I. 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, twenty- two women and ten children.*® 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 aU to ill-health 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 : and these two had together produced only three 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 twa widely different parts of Australia. The celebrated explorer, Mr. Gregory, told jlr. 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 Eiver, twelve died of consumption within three months.®* The decrease of the Maories of New Zealand has been carefully investigated by Mr. Fenton, in an admirable Eeport, from which all the following statements, with one exception, are taken.'*® The decrease in number since 1830 is admitted by every one, including the natives themselves, and is still steadily progress- ing. 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 This is tho statement of the 1870, p. 90; and the ‘Last of the Governor of Tasmania, Sir W. Deni- Tasmanians,’ 1870, p. 386. son, ‘ Varieties of Vice-Regal Life,’ ‘ Observations on the Aboriginal 1870, vol. i. p. 67. Inhabitants of New Zealand,’ pub- For these cases, see Bonwick’s lished by the Government, 1850. * Daily Life of the Tasmanians,’ Chap. VII. 185 The Extmctio7t of Races. to 1858, the decrease was 19.42 per cent. Some of the tribes, thus carefully examined, KYed 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.!" Mr. Fenton, after shewing in detail the in- sufficiency of the various causes, usually assigned in explana- tion of this extraordinary decrease, such as new diseases, the profligacy of the women, drunkenness, wars, &c., 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 non-adult for every 2'57 adults ; whereas in 1858 there was only one non-adult 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 bom 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 dis- similar 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 fertihty, 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 manufactui-ing 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 h^ already been much modified: they raised potatoes, maize, and other agricultural produce, and sxchanged them for English manufactured goods and tobacco. It is evident from many statements in the life of Bishop Patteson,^® 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 ‘New Zealand,’ by Alex. Ken- C. M. Younge, 1874; see movo nedy, 1873, p. 47. especially vol. t. p. 530. « ‘ Life of J. C. Patteson,’ by i86 The Descent of Man. Pabt 1. removed to Now Zealand, Norfolk Island, and other salubrious places, in order to be educated as missionaries. 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 : 1 Year. Native Population. (Except during 1832 and 1836, when the few foreigners in the islands were included). 1832 130,313. 1836 108, 579' 1853 71,019 1860 67,084^ 1866 58,765: 1872 51,531^ Annual rate of decrease per cent., assuming it to have b^n uniform be- tween the successive cen- suses ; these censuses be- ing taken at irregular intervals. 4-46 2-47 0-81 2’18 2-17 We here see that in the interval of forty years, between 1832 and 1872, the population has decreased no less than sixty-eight 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 aU the causes seems to be lessened fertility. According to Dr. Euschenberger of the U.S. Navy, who visited these islands between 1835 and 1837, in one district of Hawaii, only twenty-five 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 tliirty- nine had ever borne children ; and “ the official report gives an “average of half a child to each married couple in the whole Chap. VII. The Extinction of Races. 187 “ 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 Eev. 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 stiU 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 weak- ness of constitution in the children, in relation to the lessened fertility of their parents. There is, moreover, a further resem- blance 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 aU 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 mortahty, especially of the children. The islands were visited by Cook in 1779, by Vancouver in 1794, and often subsequently by whalers. In 1819 missionaries arrived, and found that idolatry had been afready 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 bom on the islands, remarks that the natives have undergone a greater change in their habits of life in the course of fifty years than Englishman 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 infroduced, and the sugar- cane 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 alcohoUc drinks became very general. Although these changes appear inconsiderable, I can well beheve, from what is known with respect to animals, that they might suffice to lessen the fertility of the natives.'*^ The foregoing statements are Islands,’ 1851, p. 277. Ruschen- taken chiefly from the following berger is quoted by Bonwick, ‘Last works : ‘Jarves’ History of the of the Tasmanians/ 1870, p, 378. Hawaiian Islands,’ 1843, p. 400-407. Bishop is quoted by Sir E. Belcher Chcever, ‘Life in the Sandwich ‘Voyage Round the World,’ 1843] The Descerit of Man. Part I. 1 88 Lastly, Mr. Macnamara states that the low aod degraded inhabitants of the Andaman Islands, on the eastern side of the Gulf of Bengal, are “ eminently suscejjtible 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 inhabit- ants of the Valley of Nepal, which is extremely hot in summer, and also the xarious hill-tribes 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 charged 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 sus- ceptible 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 stiU more interesting than their Liability to ill-health 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 caimot 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 vol. i., p. 272. I owe the census of the several years to the kindness of Mr. Coan, at the request of Dr. You- mans of New York ; and in most cases I have compared tne Youmans figures with those given in several of the above-named works. I have omitted the census for 1850, as 1 have seen two widely different num- bers given. ‘The Indian Medical Gazette, Nov. 1, 1871, p. 240. Chap. VIT. The Extinction of Races. 189 inter-breeding ; 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 inter-breeding, 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.'*® A much more probable view is suggested by the analogy of the lower animals. The reproductive system can he 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, vigomr 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 rai’ely or never bred, is a more apposite in- stance, 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.^® Certain groups of animals are much more liable than others to be affected by captivity ; and generally aU 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 ^ On the close relationship of the Scotland, Dr. Mitchell, ‘ Edinburgh Norfolk Islanders, see Sir W. Deni- Medical Journal,’ March to June, son, ‘Varieties of Vice-Regal Life,’ 1865. vol. i. 1870, p. 410. For the Todas, ■*“ For the evidence on this head see Col. Marshall’s work, 1873, p. see ‘Variation of Animals’ &c.. lie. For the Western Islands of vol. ii. p. 111. 190 The Descent of Man. Paet 1. ■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 hunting-leopard in India, many monkeys in America, and a host of animals of all kinds, on removal from their natural conditions. We can see why it is that aborigines, who have long inhar bited 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.^^ The immunity of civilised races and domesticated animals is probably due to their having been subjected to a greater extent, and therefore ha'ving 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 sub-races having inter-crossed. 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 Enghsh, 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 liko’wise in- creased so rapidly, that although sixteen of them returned to Pit- cairn Island in 1859, they numbered in January 1868, 300 souls; ‘Variation of Animals,’ &c., vol. ii., p 16. Chap. VII. TJte Extinctiofi of Races. 191 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.'*® 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, in- creased by 847 ; but I do not know whether the latter number includes the offspring from the half-castes, or only the half-castes of the first generation. 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 ill-health would probably follow, if savages were compelled by any cause, such as the imuad 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 changed conditions of life. Finally, although the gradual decrease and ultimate extinction of the races of man is a highly complex problem, depending on many causes which differ m different places and at different times ; it is the same problem as that presented by the extinc- tion of one of the higher animals — of the fossil horse, for in- stance, which disappeared from South America, soon afterwards to be replaced, within the same districts, by countless troops 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 *® These details are taken from May 29th, 1863. The following ‘The Mutineers of the “Bounty,”’ statements about the Sandwich Is- by Lady Belcher, 1870; and from landers are from the ‘Honrlulu ‘Pitcairn island,’ ordered to be Gazette,’ and from Mr. Goan, printed by the House of Commons, Past L X92 The Descent of Man. later lead to extinction ; the end, in most cases, being promptly determined by the inroads of conquering tribes. On the Formation of the Races of Man. — In some cases the ca;ossing of distinct races has led to the formation of a new race. The singular fact that 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,^* 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 giudations 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.®® Whether a heterogeneous people, such as the inhabi- tants 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 cross-breed can certainly be fixed and made uniform by careful selection®^ 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 partake in an equal degree of the characters of the two parent-races. Of all the differences between the races of man, the colour of the sln'n 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 cUmates; but Pallas first shewed that this is not tenable, and he has since been followed by almost all anthropologists.®® This view has been rejected chiefly because the distribution of the variously coloured races, most of whom must have long inhabited their ■“> ‘On Anthropology,’ transla- tion ‘ Anthropolog. Eeview,’ Jan. 1868, p. 38. “0 ‘The Annals of Rural Bengal,’ 1868, p. 134. “ ‘ The Variation of Animals and Plants under Domestication,’ vol. ii. p. 95. Pallas, ‘Act. Acad. St. Peters- burg,’ 1780, part ii. p. 69. He w.vj followed by Rudolphi, in his ‘ Bey- trage zur Anthropologie,’ 1812. An excellent summary of the evi- dence is given by Godron, ‘ De TEspfcce,’ 1859, vol. ii. p. 246, &c. Chap. VII. The Formation of Races. 193 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 antho- rity,“ have not undergone the least change of colour after residing for three centuries in Soiith Africa. An argument on the same side may likewise be drawn from the uniform appear- ance in various parts of the world of gipsies and J ews, though the uniformity of the latter has been somewhat exaggerated.*^ A very damp or a very di-y atmosphere has been sirpposed 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.®® Various facts, which I have given elsewhere, prove that the colour of the skin and hair is sometimes correlated in a surpris- ing 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 native countries, during a long series of generations. I afterwards found that this same idea had long ago occurred to Dr. Wells.®® It has long been known that negroes, and even mulattoes, are almost completely exempt from the yellow -fever, so destructive in tropical America.®^ 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 one-fifth of the white settlers to die, and another fifth to I return home invalided.®® This immunity in the negro seems to be partly inherent, depending on some unknown peculiarity of constitution, and partly the result of acclimatisation. Pouchet®® ! Sir Andrew Smith, as quoted by Knox, ‘ Races of Man ’ 1850, p. 1473. See De Quatrefages on this I head, ‘Revue des Cours Scienti- jfiques,’ Oct. 17, 1868, p. 731. Livingstone’s ‘ Travels and Re- ! searches in S. Africa,’ 1857, pp. 338, 329. D’Orbigny, as quoted by Qodron, ‘De TEspbce,’ vol. ii. p. 266. See a paper read before the loyal Soc. in 1813, and published n his Essays in 1818. I have given u account of Dr. Wells’ views in the Historical Sketch (p. svi.) to my ‘ Origin of Species.’ Various cases of colour correlated with constitu- tional peculiarities are given in my ‘ Variation of Animals under Do- mestication,’ vol. ii. pp. 227, 335. See, for instance, Nott and Gliddon, ‘Types of Mankind,’ p. 68. Major Tulloch, in a paper read before the Statistical Society, April 20th, 1840, and given in the ‘ Athe- meum,’ 1840, p. 353. ‘The Plurality of the Human Race ’ (translat.), 1864, p. 60. 0 194 The Descent of Man. Part I, states that the negro regiments recruited near the Soudan, and borrowed from the Viceroy of Egypt for the Mexican war, escaped the yellow-fever almost equally with the negroes origin- ally brought from various parts of Africa and accustomed to the climate of the West Indies. Tliat acclimatisation plays a part, is shewn by the many cases in which negroes have become some- what liable to tropical fevers, after having resided for some time in a colder climate."® The nature of the climate imder 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. Blau- found that the death-rate 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 Eev. H. B. Tristram states, that there are districts in Northern Africa which the native inhabit- ants are compelled annually to leave, though the negroes can remain with safety. 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 endeavoui-ed, with but little success,"' to ascertain how far it holds good. The late Dr. Quatrefiiges, ‘ Unite de I’Esp&ce Humaine,’ 1861, p. 205. Waitz, ‘ Introduct. to Anthropology,’ trans- lat. vol. i. 1863, p. 124. Living- stone gives analogous cases in his ‘ Travels.’ In the spring of 1862 I ob- tained permission from the Director- General 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 re- marks. but I have received no re- turns. “As several well-marked “ 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 investiga- “ tion seems worth consideration. “ Namely, whether there is any re- “ lation 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 light-coloured hair, and hair “ of intermediate or doubtful tints ; “ and if a similar .account were “ kept by the same medical gentle- Chap. VII. The Formation of Races. 195 Daniell, who had long lived on the West Coast of Africa, told me that he did not beheve in any such relation. He was himself unusually fair, and had withstood the chmate in a wonderful manner. When he fast arrived as a boy on the coast, an old and experienced negro chief predicted from his appearance that this would prove the case. Hr. Nicholson, of Antigua, after having attended to this subject, writes to me that he does not think that dai’k-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 haii-.®^ As far, therefore, as these shght 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 fever-generating miasma. Dr. Sharpe remarks,®^ 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. “ men, 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 consti- “ tutional liability to tropical dis- eases. Perhaps no such relation “ would be discovered, but the in- “ vestigation 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. Theoreti- “ cally the result would be of high “ interest, as indicating one means “ by which a race of men inhabiting “ from a remote period an un- “ healthy tropical climate, might *• have become dark-coloured by “ the better preservation of dark- haired or dark-complexioned iu- '* dividuals during a long succession “ of generations.” ‘ Anthropological Review,’ Jan. 1866, p. xxi. Dr. Sharpe also says, with respect to India Man a Spe- cial Creation,’ 1873, p. 118), that “ it has been noticed by some medi- “ cal officers that Europeans witli “ light hair and florid complexions “ suffer less fi-om diseases of tropical “ countries than persons with dark “ liair and sallow complexions ; “ and, so flir as I know, there ap- “ pear 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. ‘ Man a Special Creation,’ 1873. p. 119. 0 2 196 The Descent of Man. Part I. although lai'ger than freckles, and that these patches were never affected by sun-burning, •whilst the ■white parts of his skin have on several occasions been much inflamed and blistered. With the lo'wer animals there is, also, a constitutional difference in liability to the action of the sun bet'ween those parts of the skin clothed •with ■white hair and other parts.®^ Whether the saving of the skin from being thus burnt is of sufficient impor- tance 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 lighter-coloured Hindoos have resided in India for a shorter time than the darker aborigines of the central and southern parts of the peninsula. Although with our present knowledge we cannot account for the differences of colour in the ]’aces 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.®® 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 extraordinarily rapid change of appearance. Their bodies and limbs become elongated; and I hear from Col. Bemys 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 ready-made clothes manufactui’ed for the American market, and which were much too long for the men in every way. There is, also, a con- siderable body of evidence she^wing that in the Southern States the house-slaves of the third generation present a markedly different appearance from the field-slaves.®® 01 ‘ Variation of Animals and Plants undor Domestication,’ vol. ii. pp. 336, 337. “0 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. Kolle (‘ Dor Mensch, seine Abstam- mung,’ &c., 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 in- forms me that the Quichuas in the Andes vary greatly in colour, ac- cording to the position of the valleys inhabited by them. Harlan, ‘Medical Rese.arches.’ p. 532. Quatrefages (‘ Unite' de I’Espbce Humaine,’ 1861, p. 128) has collected much evidence on this head. Chap. VII. TJi£ Formation of Races. 197 If however, we look to the races of man as distributed over the world, we must infer that their characteristic differences can- not be accounted for by the direct action of different conditions of Ufe, 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 produc- tions of then’ 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 to a nearly similar climate, and follow nearly the same habits of life. 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 habitu- ally 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 sense-organs 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 use — the habitual play of different muscles serving to express different emotions — and the increased size of the brain from gre-ater intellectual activity, have together produced a considerable effect on their general appearance when compared with savages.®" Increased bodily stature, without any corresponding increase in the size of the brain, may (judging from the pre- viously adduced cnse of rabbits), have given to some races an elongated skull of ho dolichocephalic type. Lastly, the little-understood principle of correlated develop- ment has sometimes come into action, as in the case of great muscular development and strongly projecting supra-orbital 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.®® The colour also of the sldn, and the odour ®' See Prof. SchaalThaTisen, trans- Mr. Catlin states (‘N. Aineri- lat. in ‘Anthropological Review,’ can Indians,’ 3rd edit. 1842, vol. 1, Oct. 1868, p. 429. p. 49) that in the whole trihe of 198 The Descent of Maft. Pabt J. emitted Ly it, are likewise in some manner connected. With the breeds of sheep the number of hairs within a given space and the number of the excretory pores are related.'® If we may judge from the analogy of our domesticated animals, many modifica- tions of structure in man probably come rmder this principle of correlated development. We have now seen that the external characteristic differences between the races of man cannot be accounted for in a satisfac- tory 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 inquire Avhether slight individual differences, to which man is emi- nently liable, may not have been preserved and augmented during a long series of generations tkrough 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 varia- tions being of an indifferent natui’e, and to their having thus escaped the action of natural selection. We have thus far been baffled in all oiu’ 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 indivi- duals arc 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 the Mnndans, about one in ten or fine and soft. twelve of the members, of all ages On the odour of the skin, and both sexes, have bright silvery Godron, ‘ Sur I’Espfece,’ tom. ii. p. grey hair, which is hereditary. 217. On the pores in the skin, Now this hair i.s as coarse and Dr. Wilckens, ‘Die Aufgabcn der harsh as that of a horse's mane, Landwirth. Zootechnik,’ 1869, 6. 7 , whilst the hah’ of other colours is Chap. YII. Structure of the Brain. 199 mil-nnwm agencies which induced them were to act in a more constant manner, aided by long-continued intercrossing. Such variations come under the provisional class, alluded to in our second chapter, which for the 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 ou' innumerable animals. It can further be shewn that the differences between the races of man, as in colour, hamness, form of features, &c., are of a kind which might have been expected to come under the influence of sexual selection. Birt 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 retarn to man, and, after attemptiog to shew how far he has been modified through sexual selection, will give a brief summary of the chapters in this First Part. Note on* the Eesemblances and Differences in the Structure AND the Development op the Brain in Man and Apes. By Professor Huxley, P.E.S. The controversy respecting the nature and the extent of the differ- ences 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 re-asserted, 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 man. But the truth that the three structures in question are as well deve- loped in apes’ as in human brains, or even bettei- ; and that it is character- istic of all the Primates (if we exclude the Lemurs) to have these parts well developed, stands at present on as seomu a basis as auy 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 gyii which appear upon the surface of the cerebral hemispheres in mau and the higher apes, t^t 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 tor the other. On this point there is no difference of opinion. Some years since, Professor Bischoff published a memoir 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 ‘Die Grosshirn-Windungen des Menschen;’ ‘ Abhaudlungen der K Cayerischen Akademie,’ Bd. x., 1868. Paht 1, 200 The JJescent of Man. differences between apes and men in this respect, I am glad to make a citation from him. “ 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 fiom the point of view of organisation alone, no one probably “ would ever have disputed (he view of Linnajus, that man should l)o “ placed, merely as a peculiar species, at the head of the mammalia and or those apes. Both shew, in all their organs, so close an aflSnity, 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 Ihe important differences which they present, come very close to one “ another ” (1. c. p. 101). Tliere remains, then, no dispute as to the resemblance in fundamental characters, between the ape's brain and man’s ; nor any as to the won- derfully 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 ot the highest apes and that of man, is there any serious question as to the natoe 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 munbcr of secondary plications. And it is admitted that, as a rule, in man, the temporo-occipital 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 diS'erences constitutes a shaqj 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 “ 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 in another specimen, “ also the right hemisphere, it proceeded for four-tenths of an inch out- “ wards, and then extended downwards, ns 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 dis- “ tinctness in the brain of most Quadi'umaiia, 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 “ fissme, the shorter is the external parieto-occipital fissure.’’ (1. c. p. 12.) The obliteration of the external perpendicular fissure of Gratiolet. therefore, is not a constant character of the human brain. On the other hand, its Ml development is not a constant character of the higher ape’s brain. For, in the chimpanzee, the more or less extensive oblitsra- tion of the external perpendicular sulcus by “ bridging convolutions,” on one side or the other, has been noted over and over again by Prof ‘ Convolutions of the Human Cerebrum Topographically Considered 186G, p. 12. Chap. VII. Sinicttire of the Brain. 201 EoUeston, Mr. Marshall, M. Broca and Professor Turner. At the conclusion of a special paper on this subject the latter mites The three specimens of the brain of a chimpanzee just described, “ prove, that the generalisation which Gratiolet has attempted to draw of “^e 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 bridg- “ ing convolution, I am inclined to think that it has existed in one hemi- sphere, 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 communi- *' cation. The asymmetrical arrangement in the convolutions of the “ two hemispheres, which previous observers have referred to in their “ descriptions is also well illustrated in these specimens.” (pp. 8, 9.) Even were the presence of the temporo-occipital, or external per- pendicular, 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 Platyrhine apes. In fact while the temporo-occipital is one of the most constant of sulci in the Catarhine, or Old World, apes, it is never very strongly developed in the New World apes; it is absent in the smaller Platyrhini; rudimentary in Pithecia and more or less obliterated by bridging convolutions in Ateles. 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 convolu- tion 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 consider- ably less complicated and more symmetilcal 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. (‘ L’ordre des Primates,’ p. 165, fig. 11.) Again, as respects the question of absolute size, it is established that the difference between the largest and the smallest healthy human brain is ^eater than the difference between the smallest healthy human brain and the largest chimpanzee’s or orang’s brain. Moreover, there is one chcumstance in which the orang’s and chim- panzee’s brains resemble man’s, but in which they differ from the lower apes, and that is the presence of two corpora candicantia — the Cynomorplia having but one. In view of these facts I do not hesitate in this year 1874, to repeat and insist upon the proposition which I enunciated in 1863.'^ So far as cerebral structoo goes, therefore, it is clear that man Notes more especially on the bridging convolutions in the Brain of the Chimpanzee, ‘ Proceedings of the Royal Society of Edinburgh,’ 1865-6. Flower ‘On the Anatomy of Pithecia Monachus,’ ‘ Proceedings of the Zoological Society,’ 1862. ‘ Man’s Place in Nature,’ p. 102. 202 The Descent of Man. Paut L *• diifars less from the chimpanzee or the orang, than these do even “ from the monkeys, and tnat 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 llischoff 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 succes- “ sively 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 Korilia, and so “on of a Hylohates, Semnopithecus, CynocepJialus, CercopithecHS, 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 between the brain of a man and that of an “ orang or chimpanzee.” 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 top. 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 know- “ ledge 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 well-developed hippocampus minor.” 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 tho 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 Eapale out of its natural place, as Professor Bischoff most unaccountably does, we write tho series of animals he has chosen to mention as follows : Homo, Pithecus, Troglodytes, Hylohates, Semnopithecus, CynocepJialus, Cercopitliecus, Macacus, Cebus, Callithrix, Hapale, Lemur, Stenops, I venture to reaffirm that the great break in this series lies between Hapale and Lemur, and that tills break is considerably greater than that between any other two terms of that series. Professor Bischofl’ ignores tho fact that long before he wrote, Gratiolet had suggested tho separation of the Lemurs from the other Primates on tho very ground of tho diflerenco in their cerebral characters ; and that Professor Flower had made tho following observations in the course of his description of tho brain of tho Javan Loris ” ‘Transactions of the Zoological Society,’ vol. v. 1862. Chap. VII. SirucUire of the Brain. 203 “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 family in other respects, viz., the lower members ot the Platyrhine group.” So far as the structure of the adult brain is concerned, then, the very considerable additions to oxn- 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 agree- ment 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 man — consisting in this ; that, in the apes, the sulci which first make their appearance are situated on the posterior region of the cerebral hemi- spheres, while, in the human foetus, the sulci first become visible on the frontal lobes."” 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 (1. c. p. 39), and the other of a human foetus at the 22nd or 23rd week of uterogestation, in which Gratiolet notes that the insula was un- covered, but that nevertheless “ des incisures sement le lobe anterieur, “ une scissure peu profonde indique la separation du lobe occipital, tres- “ Chez tous les singes, les plis “ posterieurs se ddveloppent les pre- “ miers ; les plis antdrieurs se “ ddveloppent plus tard, aussi la “ vertdbre occipitale et la paridtale “ sont-elles relativement trds-grandes “ chez le fcetus. L’Homme prdsente “ une exception remarquable quant “ i I’dpoque de I'apparition des plis “ frontaux, qui sont les premiers “ indiquds ; mais le ddveloppement “ gdndral du lobe frontal, envisagd “ seuiement par rapport i son “ volume, suit les mdmes lois que dans “les singes:” Gratiolet, ‘Mdmoire sur les plis cdrdbraux de I’Homme et des Primates,’ p. 39, Tab. iv. fig. 3. Gratiolet’s words are (1. c. p. 39) : “ Dans le foetus dont il s’agit “ les plis cdrdbraux postdrieurs sont “ bien ddveloppds, tandis que les “ plis du lobe frontal sont i peine “ indiquds.” 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 Gratio- let ’ (Mdm. de la'Socidte' d’Anthro- pologie de Paris,’ 1868, page 32.), writes thus : “ Gratiolet a eu entre “ les mains le cerveau d’un foetus de “ Gibbon, singe dminemment su- “ pdrieur, et telleraent rappi-ochd de “ I’orang, que des naturalistes trds- “ compdtents I’pnt rangd parmi les “ anthropoi'des. M. Huxley, par ex- “ emple, n’hesite pas sur ce point. “ Eh bien, c’est sur le cerveau d’un “ fcetus de Gibbon que Gratiolet a “ vu fcs circonvolutions du lobe tcm- “ poro-sphenoidal dejd developpees “ lorsqu’il n’existent pas encore deplis “ sur le lobe frontal. II dtait done “ bien autorisd a dire que, chez “ I’homme les circonvolutions appa- “ raissent d’o en w, tandis que chez “ les singes elles se ddveloppent “ d’oo en a.” 204 The Descent of Man. Paut I. “ reduit, d’ailleurs diis cette epoque. Le reste de la surface cerebralc “ est encore absolunent lisse.” Three views of this brain are given in Plate II. figs, 1, 2, 3, of tie work cited, shewing the upper, lateral and inferior views of the bemi- spheres, 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 (anterotemporal) on the posterior half of the face of the hemisphere, is more marked than any of those vaguely indicated in the anterior lialf. If the figui-e is correct it in no way justifies Gratiolet’s conclusion : “ II y a done entre ces cerveaux [those of a Callithrix and of a Gibbon] et “ celui du foetus humain une diflerence fondamental. Chez celui-ci, long- “ temps avant que les plis temporaux apparaissent, les plis frontaux “ essayent d’exister.” 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,’® and more particularly by Ecker,'“ whose work is not only the latest, but by far the most complete, memoir on the subject. The final results of their inquiries may be summed up as follows : — 1. In the hrunan foetus, the sylvian fissure is formed in the course of the third month of uterogestation. In this, and in the fom-th month, the cerebral hemispheres are smooth and rounded (with the exception of the sylvian depression), and they project backwards far beyond the cerebellum. 2. The sulci, properly so called, begin lo appear in the interval between the end of the fom'th 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 frontal or the temporal sulci the earliest. The first which appears, in fact, lies on the inner face of the hemi- sphere (whence doubtless Gratiolet, who does not seem to have examined that face in his foetus, overlooked it), and is either the internal perpen- dicular (occiijito-parietal), or the calcarine sulcus, these two being close together and eventually running into one another. As a rule the occipito-parietal is the earlier of the two. 3. At the latter part of this period, another sulcus, the “ posterio, parietal,” or “ Fissure of Eolando ” 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 (1. c. p. 212-13, Taf. II. figs. 1, 2, 3, 4), the antero- temporal sulcus (scissure parallele) so characteristic of the ape’s brain, IS as well, if not better developed than the fissure of Eolando, and is much more marked than the proper frontal sulci. 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 ■8 ‘ Ueber die typische Anordnung der Furchen und Windungen auf den Grosshirn-Hemisp-.iiren des Menschen und der Affen.’ ‘ Archiv fdr Anthropologic,’ iii., 1868. ■“ ‘ Zur Entwickclungs Geschichte der Furchen und Windungen der Grosshirn-Heraisphareu im Feetus des Menschen.’ ‘ Archiv fiir Anthro- pologie,’ iii., 1868. Chap. VII. Structure of the Brain. 205 view that man has been evolved from some ape- like form ; though thero van be no doubt that that form was, in many respects, different from any member of the Primates now living. 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 iiiiimal 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 cha- l acters of a fish, and, if it went no further, would have to be grouped among fishes. But it is equally true that a tadpole is v^y different from any known fish. 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 marmoset-like 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 he 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 Platyrhini proper, the only observation with which I am acquainted is due to Pansch, who found in the brain of a fcetal Cebus Apella, in addition to the sylvian fissure and the deep calcarine fissure, only a very shallow anterotemporal fissure (scissiire parallele of Gratiolet.) Now this fact, taken together with the circmnstance that the antero- temporal sulcus is present in such Platyrhini 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 l)osterior sulci appear before the anterior, in the brains of the Platyrhini. But, it by no means follows, that the rule which may hold good for the Platyrhini extends to the Gatarhini. We have no in- formation whatever respecting the development of the brain in the Cynnmorpha; 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 do not appear in the same order as a man’s. a opens his preface with the aphorism. “ II est dangereux ‘ dans les sciences de conclure trop vite.” I fear he must have for- gotten this sound maxim by the time he had reached the discussion of 1 between men and apes, in the body of his work. Nc excellent author of one of the most remarkable contributions to the just understanding of the mammalian brain which has ever been r, ^ been the first to admit the insuificiency of his data had he lived to profit by the advance of inquiry. The misfortune is that hra conclusions have been employed by persons incompetent to appreciate their foundation, as arguments in favour of obscuranti3m.*“ For example, M. I’Abbd Lecomto winisme et I’origine de I’Homme m his terrible pamphlet ‘Lo Dar- 1873. 206 The Descent of Man. Past I. 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 sulei, 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 i^rimaben (leaving out the Lemurs) ; and that this is exactly what we should expect to be the case, if man has resulted from the gradual modifica- tion of the same form as that from which the other Frimates have sprung. C 207 ) Part II, SEXUAL SELECTION, CHAPTER Vin. Pkinciples of Sexual Selection. Secondary sexual characters — Sexual selection — Manner of action — Ex- cess of males — Polygamy — The male alone generally modified through sexual selection — Eagerness of the male — Variability of the male — Choice exerted hy the female — Sexual compared with natural selection — Inheritance, at corresponding periods of life, at corresponding seasons of the year, and as limited by sex — Relations between the several forms of inheritance — Causes why one sex and the young are not modified through sexual selection — Supplement on the proportional numbers of the two sexes throughout the animal kingdom — The proportion of the sexes in relation to natural selection. ■With animals -wliicli have theif 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 charac- ters, which are not directly connected with the act of reproduc- tion ; for instance, the male possesses certain organs of sense or locomotion, of which the female is quite destitute, or has them more highly-developed, 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 hito 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 tho 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 called primary and which secondary. The female often differs from tho male in having organs for tho noui’ishment or protection of her young, such as the mammary 2o8 The Descent of Man. Part II. 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 he given, but they do not here concern us. There are, however, other sexual differences quite unconnected with the primary reproductive organs, and it with is these that we are more especially concerned — such 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, his power of song, and other such characters. Besides the primary and secondary sexual differences, such as the foregoing, the males and females of some animals differ iu structui’es related to different habits of hfe, and not at aU, or only indirectly, to the reproductive functions. Thus the females of certain flies (Cuhcidse and Tabanddse) are blood-suckers, whUst the males, living on flowers, have mouths destitute of mandibles.* The males of certain moths and of some crustaceans (e.y. Tanais) have imperfect, closed mouths, and cannot feed. The complemental males of certain Ch-ripedes hve 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 glow-worm is destitute of wings, as also are many female moths, some of which never leave theu’ cocoons. Many female parasitic crustaceans have lost them natatory legs. In some weevil-beetles (Curcu- liouidaB) there is a great difference between the male and female in the length of the rostrum or snout ; * but the meaning of this and of many analogous differences, is not at all understood. Differences of structui’e 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 gi'eat, and we hear from Dr. Duller* * Westwood, ‘ Modern Class, of Kirby and Spence, ‘ Introduc- Insects,’ vol. ii. 1840, p. 541. For tion to Entomology,’ vol. iii. 1826, the statement about Tanais, men- p. 309. tioned below, I am indebted to Fritz * ‘Birds of New Zealand,’ 1872, Muller. p. 66. Chap. VIII. Sexual Selection. 209 that the male uses his strong beak in chiselling the larvfe 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 Hves 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 rendered such powers useless. AVe 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 theic offspring best, would leave, coeteris imribus, 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 be- cause 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 i 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 r 210 The Descent of Man. Part II. like a rasp, and with this they coil round and permanently hold the females.* 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 bo 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 well- endowed 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 j>rehensile 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 then- 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 pm’poses of life I shall pass them over almost entii’ely, giving only a few instances under each class. There are many other structures and instincts which must have been developed through sexual selection— such as the weapons of offence and the means of defence of the males for fighting with and driving away their rivals— their courage and pugnacity — their various ornaments— their contrivances for pro- * M. Perrier advances this case (‘Revue Scientifique,’ Feb. 1, 1873, p. 865) as one fatal to the belief in sexual selection, inasmuch as he .supposes that I attribute all tlie 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 2uglish naturalist insists that the claspers of certain male animals could not have been developed through the choice of the female ! Had 1 not met with this remark, 1 should not have thought it possible for any one to have read this chapter and to h.ave imagined th.at I mnin- t£iin that the choice of the female had anything to do with the develop- ment of the prehensile organs in the male. Chap. VIII. Sexual Selection. 21 1 ducing Tocal or instrumental music — and 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 rmarmed, 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 imarmed and imornamented, are able to survive and procreate their kind. Secondary sexual characters of the kind just referred to, will bo 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 ot either sex. When we behold two males fighting for the possession of the female, or several male birds displaying their gorgeous plumage, and per- forming strange antics before an assembled body of females, we cannot doubt that, though led by instinct, they know what they are about, and consciously exert their mental and bodily powers. Just as man can improve the breed of his game-cocks 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, how- ever 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 here- after, 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 com- parison would bo 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. Prom our ignorance on several points, the precise manner in p 2 212 The Descent of Man. Part IL which sexual selection acts is somewhat uncertain. Neverthe- less if those naturalists who already believe in the mutability of species, will read the following chapters, they Avill, 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 suppo- sition that their mental capacity sufiSces for the exertion of a choice. In many cases special circumstances tend to make the struggle between the males particularly se-^ere. 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 bird- catchers assert that this is invariably the case with the nightin- gale 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 aiTival, and he has never known the females of any species to arrive before their males. During one spring he shot thirty-nine males of Bay’s wagtail (fudytes JRaii) 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.® 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.® 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 oflspring ; and these ’ J. A. Allen, on the ‘Mammals and Winter Birds of Florid.a,’ Bull. Comp. Zoology, Harvard College, p. 268. “ Even with those plants in which the sexes are separate, the male flowers are generally mature be- fore the female. As first shewn by C. K. Sprengel, many hermaph- rodite plants are dichogamous ; that is, their male and female organs are not ready at the same time, so that they cannot be self-fertilised. 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. Ohap. VIII. Sexual Selection. 213 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 young — a period which must be determined by the seasons of the year. On the whole there can be no doubt that with almost aU animals, in which the sexes are separate, there is a constantly recurrent struggle between the males for the possession of the females. Our difficulty in regard to sexual selection lies in understand- ing how it is that the males which conquer other males, or those Avhich 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 best-endowed males. Prom 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 better-armed 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 beheve that any great inequahty 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 better-nourished 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, be.st-nourishcd and earliest breeders would on an average succeed in rearing the largest number of fine offspring.'^ The males, as we have seen, are generally ready to breed before the ’ Here is excellent evidence on nn experienced ornithologist. Mr. iiie char.ncter of the oflspring from J. A. Allen, in speaking Mammals 214 The Descent of Man. Paht II. females ; the strongest, and with some species the Ixist armed of the males, drive away the weaker ; and the former would then unite with the more vigorous and better-nourished females, be- cause they are the first to breed.® Such vigorous pairs would surely rear a larger number of ofispring 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, strength and courage of the males, or to improve their weapons. 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 pau-ing 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.” 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 at- tractive. Both sexes, therefore, of such early pairs would as above explained, have an advantage over others in rearing oifejpring ; and this appai-ently has sufficed dui-ing a long course of generations to add not only to the strength and fighting poweiB 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 pans would have an advan- 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 paler-coloured than “ those hatched earlier in the sea- “ son. 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 per- “ feet and vigorous.” “ 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 den Darwin’sehen Lehrc auf Bienen,’ ‘ Verb. d. V. Jahrg.’ xxi.v. p. 45. ® With respect to poultry, I have received information, hereafter tc be given, to this efl'ect. Even with birds, such ns pigeons, which pair for life, the female, as I hear from Mr. Jenner Weir, will dn.sert her mate if he is injured or grows weak. Chap. VIII, Sexual Selectio?i. 215 tage in rearing offspring, more especially if the male had the power to defend the female during the pairing-season as occurs with some of the higher animals, or aided her in providing for the young. The same principles would apply if each sex pre- ferred and selected certain individuals of the opposite sex; supposing that they selected not only the more attractive, but likewise the more vigorous individuals. Numerical Proportion of the Two Sexes. — I have remarked that sexual selection would be a simple affair if the males were con- siderably more numerous than the females. Hence I was led to investigate, as far as could, the proportions between the two sexes of as many animals as possible ; but the materials are scanty. I wiU here give only a brief abstract of the results, retaining the details for a sup2Dlementary discussion, so as not to interfere with the course of my argument. Domesticated animals alone afford the means of ascertaining the propor- tional 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 aj)pears that with most of our domestic animals the sexes are nearly equal at bhth. Thus 25,560 births of race-horses have been recorded during twenty-one years, and the male births were to the female births as 99’7 to 100. In greyhounds the in- cquahty is greater than with any other animal, for out of 6878 births dming twelve years, the male births were to the female as HOT to 100. It is, however, in some degi’ee doubtful whether it is safe to infer that the proportion would be the same imder 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 lOl'S, in Eussia as 108'9, and with the Jews of Livonia as 120, to 100 female births. But I shall recui’ 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 female children. For our present purpose we are concerned with the proportion of the sexes, not only at birth, but also at maturity, and this adds another element of doubt ; for it is a well-ascertained fact that with man the number of males dying before or during birth, and during the first few 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 Idll one another by fighting ; or they drive one another about 2I6 T he Descent of Man. Paet II. until they become greatly emaciated. They must nlso be often exposed to various dangers, whilst wandering about in eager search for the females. In many kinds of fish the males arc much smaller than the females, and they are beheved 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 larva 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 natnre, 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 inseets, are considerably more numerous than the females. The proportion between the sexes fluctuates slightly during successive years : thus with race-horses, for every 100 mares bom 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 lai’ger num- bers 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 at- tractive males previously produced would still have at least as good a chance of leaving ofispring as the w^eaker or less attractive. Polygamy. — The practice of polygamy leads to the same results as would follow from an actual inequality in the number of tho sexes; for if each male secures two or more females, many males eaimot pair ; and the latter assuredly will be the weaker or less attractive individuals. Many mammals and some few birds axe Chap. VII L Sexual Selectiojt. 217 polygamotis, 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 strongly-marked secondary sexual characters ; whilst some few animals, which are polygamous, do not have such characters. We wiU first briefly run through the mammals, and then turn to birds. The gorilla seems to be polygamous, and the male differs considerably from fhe 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 well- marked sexual differences, in colour, beard, and vocal organs ; and the male generally lives with two or three wives : the male of the Cehus capucinus differs somewhat from the female, and appears to be polygamous.'® Little is Icnown on this head vsdth 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 Aniilope saiga appears to be the most inordinate polygamist in the world ; for Pallas" 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 well-marked sexual On the Gorilla, Savage and Wyman. ‘ Boston Journal of Nat. Hist.’ vol. V. 1845-47, p. 423. On Cynocephalus, Brehm, ‘ Illust. Thier- leben,’ B. i. 1864, s. 77. On My- cetes, Rengger, ‘Natnrgesch.: Siiuge- thiere von Paraguay,’ 1830, s. 14, 20. Cebus, Brehm, ibid. s. 108. " Pallas, ‘Spicilegia Zoolog., Fasc. xii. 1777, p. 29. Sir Andrew Smith, ‘ Illustrations of the Zoology of S. Africa,’ 1849, pi. 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 gre- garious. 2i8 The Descent of Man. Taut II. characters, in his great tusks and some other points. In Europe and in India he leads a solitary life, except during the brcefling- season ; 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 one-fifth more than the females.^* 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 Piodents being polygamous, excepting that amongst the Eodents, the common rat, according to some rat-catchers, hves 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.^® And many kinds of bats (Cheh’optera) present well-marked sexual differences, chiefly in the males possessing odoriferous glands and pouches, and by their being of a lighter colour.^^ In the great order of Eodents, as far as I can learn, the sexes rarely differ, and when they do so, it is but shghtly 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 well-marked sexual characters. If, however, we tui-n 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 sea-elej.)hant of the Southern Ocean always possesses several females, and the sea-lion of Forster is said to be surrounded by from twenty to thirty females. In the North, the male sea-bear of Steller is accompanied by even a Dr. Campbell, in ‘ Proc. Zoo- “ Dr. Gr.ay, in ‘ Annals and log. Soc.’ 1869, p. 138> See also an Mag. of Nat. Hist.’ 1871, p. 302. interesting paper, by Lieut. John- *■* See Dr. Dobson’s e.Tcelleut Btonc, in ‘ Proc. Asiatic Soc. of paper, in ‘ Proc. Zoolog. Soc.’ 1873- Bengal,’ May, 1868. p* -•11. Chap. VIII. Sexual Selection. 219 gi-eater number of females. It is an interesting fact, as Dr. Gill remarks,^® 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 liarems, the males are vastly “ larger than the females.” Amongst birds, many species, the sexes of which differ greatly from each other, are certainly monogamous. In Great Britain we see well-marked sexual differences, for instance, in the wild- duck 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 Mi-. Wallace doubts whether he had sufficient evidence. ]VIr. Salvin tells me he has been led to believe that humming-birds are polygamous. The male widow-bird, remarkable for his caudal plumes, certainly seems to be a polygamist.^® I have been assured by Mr. Jenner Weir and by others, that it is somewhat common tor three starlings to frequent the same nest ; but whether this is a case of polygamy or polyandry has not been ascertained. The Galhnaceae exliibit almost as strongly marked sexual differences as bhds of paradise or humming-birds, 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 mono- gamous guinea-fowl or partridge ! Many similar cases could be given, as in the grouse tribe, in which the males of the poly- gamous capercailzie and black-cock differ greatly from the females; whilst the sexes of the monogamous red gi’ouse and ptarmigan differ very little. In the Cursores, except amongst the bustards, few species offer strongly-marked sexual dif- ferences, and the great bustard {Otis tarda) is said to be poly- gamous. With the Grallatores, extremely few species differ sexually, but the ruff {Machetes puynax) affords a marked The Eared Seals, ‘ American ^’atul•alist,’ vol, iv., Jan. 1871. ‘The Ibis,’ vol. iii. 1861 p. 133, on the I’rogne Widow-bird. See also on the V idua axillaris^ ibid. vol. ii. 1860, p. 211. On the polygamy of the Capercailzie and Great Bustai-d, see L. Lloyd, ‘ Game Birds of Sweden,’ 1867, p. 19, and 182. Montagu and Selby speak of the Black Grouse as polygamous and of the Red Grouse as mono- gamous. 220 The Descc7it of Man. Part II. 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 strongly-marked sexual diiferenees. I asked Mr. Bartlett, of the Zoological Gardens, who has had very large experience with bird^, whether the male tragopan (one of the Gallinaceae) was polygamous, and I was struck by his answering, “ I do not “ know, but should think so from his splendid colours.” It deserves notice that the instinct of pairing with a single female is easily lost under domestication. The wild-duck is strictly monogamous, the domestic-duck highly polygamous. The Eev. W. D. Fox informs me that out of some half-tamed wild-ducks, 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 guinea-fowl is strictly monogamous ; but Mr. Fox finds that his birds succeed best when he keeps one cock to two or three hens. Canary-birds 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 stickle -back (Gasterosteus), however, is said to be a polygamist and the male during the breeding season 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 niunber of vigorous offspring will be reared from the pairing of the strongest and best-armed males, victorious in contests over other males, with the most vigorous and best-nourished 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 win 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 ad- vantage thus gained by the more vigorous pairs in rearing a larger niunber of offspring has apparently sufficed to render sexual selection efficient. But a large numerical prepondenince u Nccl Humphreys, ‘ River Gardens,’ 1857. Chap. YIII. Sexual Selection. 221 of males over females vrill be still more efBcient; whether the pi-epouderance is only occasional and local, or permanent; whether it occurs at birth, or afterwards from the greater de- struction of the females ; or whether it indirectly follows from the practice of polygamy. The Male generally more modified than the Female. — Throughout the n.niTufi.1 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 then- 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 here- after. 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 then- 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 Kuby remarks,^® “ the law is, that the male shall seek “ the female.” Two good authorities, l\Ir. 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.'® Kirby and Spence, ‘Introduc- tion to Entomology,’ vol. iii. 1826, p. 342. ** One parasitic Hymenopterous insect (Westwood, ‘ Modern Class, of Insects,’ vol. ii. p. 160) forms an exception to the ruk, as the male has rudimentary wings, and never quits the cell in which it is born, whilst the female has well-developed wings. Audouin believes that the females of this species are impreg- nated 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, In which the female, instead of the male, is the seeker and wooer. 222 The Descent of Man. Part 11, The female, on the other hand, with the rarest exceptions, is less eager than the male. As the illustrious Hunter “ 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 shoTO 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 law almost as general as the eagerness of the male. 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 court- ship. 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 fertili- sation have to be nourished for a time; hence the pollen is necessarily brought to the female organs — being placed on the stigma, by means of insects or the wind, or by the spontaneous movements of the stamens ; and in the Algae, &c., by the loco- motive power of the antherozooids. With lowly-organised aquatic animals, permanently aflaxed to the same spot and having their sexes separate, the male element is invariably brought to the female ; and of this. wo 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 gi-eater 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 re- spect, analogous with plants.^* 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 pos- sible, 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 ‘ Essays ami Observatious.’ of the male and female reproductive edited by Owen, vol. i. 1861, p. cells, remarks, “ vcrhdlt sich die 194_ “ eine bei der Vercinijrung activ. Prof. Sachs (‘ Lehrbuch der “ . . . die audere crschcint bei der Botanik,’ 1870, s. 633) in speaking “ Vcrcinigung passiv.” Chap. VIII. Sexual Selection. 223 nnimaJs, the females alone are fixed, and the males of these must be the seekers. But it is difBcult 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 efiSciently, it would be necessary that they should be endowed with strong passions ; and the acquire- ment of such passions would naturally follow from the more eager leaving a larger number of oiispring than the less eager. 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 females — as I concluded they were — after a long study of domesticated animals. Von Nathusius, who has had very wide experience, is strongly of the same opinion.^^ Good evidence also in favour of this conclusion can be produced by a comparison of the two sexes in manldnd. During the Novara Expedition 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 recxir to this subject in a future chapter. Mr. J. Wood,^^ 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 Macalistcr likewise remarks 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 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 "■ ‘ Vortrage iiber Viehzucht,’ 1872, p. 63. ‘ Keise der Novara : Anthro- polog. Theil,’ 1867, s. 216-269. The results were calculated by Dr. VVcisbach 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. ‘ Proceedings Koyal Soc.’ vol. svi. July 1868, j)p. 519 and 524. ** ‘ Proc. Koyal Irish Academy,’ vol. X. 1868, p. 123. ‘ Massachusetts Medical Soc, vol. ii. No. 3, 1868, p. 9. 224 Paet II The Descent of Man. 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 woman.^ Lastly the temperature is more variable in man than in woman.** 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, inteUigible. Tlirough the action of sexual and natural selection male animals have been rendered in very many instances widely different from their females; but in- dependently of selection the two sexes, from differing constitu- tionally, 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, &c. : and this expenditure is generally concentrated within a short period. The great vigour of the male duriug the season of love seems often to intensify his colours, independently of any marked dif- ference from the female.** 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.*® On the whole the expenditure of matter and force by the two sexes is probably nearly equal, though effected in very different ways and at different rates. From the causes just specified the two sexes can hardly fail to differ somewhat in constitution, at least during the breeding season; and, although they may be subjected to exactly the same conditions, they wiU 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. Never- theless, they may become permanent if the exciting cause acts ‘Archiv fiir Path. Anat. und Phys.’ 1871, p. 488. -• The conclusions recently ar- rived at by Dr. J. Stockton Hough, on the temperature of man, are given in the ‘ Pop. Science Review,’ Jan. 1st, 1874, p. 97. Prof. Mantegazza is inclined to believe (‘ Letters a Carlo Darwin,’ ‘ Archivio per 1’ Anthr opologi.a,’ 1871, p. 306) that the bright colours, common in so many male animals, are due to the presence and retention by them of the sperm- atic fluid; but this can h.ardly be the case ; for many male birds, for instance young pheasants, become brightly coloured in the autumn of their first year. For mankind, see Dr. J. Stock- ton Hough, whose conclusions are given in the ‘ Pop. Science Review,' 1874, p. 97. See Girard’s observa- tions on the Lepidoptera, as given in the ‘ Zoological Record,’ 1869, p. 347. Chap. Vlll. Sexual Selection. 225 permanently ; and in accordance with a frequent form of inheri- tance 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 speci- mens &om the south are darker-coloured than those from the north ; and this seems to be the direct result of the difference in temperature, hght, &c., between the two regions. Now, in some few cases, the two sexes of the same species appear to have been differently affected ; in the Agelosus phoeniceus the males have had their colours greatly intensified in the south ; whereas with Car- dinalis 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.®^ A few exceptional cases occur in various classes of animals, in which the females instead of the males have acquii'ed well pronounced secondary sexual characters, such as brighter colours, greater size, strength, or pugnacity. With birds there has some- times 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 beauti- ful 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 plausi- bility, 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 ‘ Mammals and Birds of E. Florida,’ pp. 234, 280, 295. Q 226 The Descent of Man. Pabt II j of the habits of animals, tliis view is hardly probable, for tlie j male is generally eager to pair with any female. It is more j probable that the ornaments eommon to both sexes were acquired j by one sex, generally the male, and then transmitted to the off- I spring of both sexes. If, indeed, during a lengthened period tlio 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 occm*, a double, but not simultaneous, process of sexual selection might easily bo 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 orna- ments, 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 i black or white. Obscure tints have often been developed 1 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 1 1 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 i 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 poly- gamous, obtains fewer females ; so that they leave fewer, less vigor- i : ous, or no offspring. In regard to structures acquired through I 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 feihale, 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 I Chap. VIII. Sexual Selection. 227 by secondaxy sexual characters. Neyertheless, 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 them -vital powers, or by exposing them to any great danger. The development, however, of certain structures — of the boms, for instance, in certain stags — has 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 conquer- ing other males in battle or courtship, and thus lea-ving 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 important than the power to conquer other males in battle. LAWS OF INHKEITANOE. 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 pf inheritance, as far as they are kno-wn. 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 dis- tinction 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 1 are present in both sexes, is manifest when two species, having strongly-marked sexual characters, are crossed, for each trans- mits the characters proper to its own male and female sex to the hybrid offspring of either sex. The same fact is like-wise mani- ! fest, when characters proper to the male are occasionally deve- ) loped 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 l cock. Conversely, the same thing is e-vident, more or less plainly, f 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 5 I appear in the young and healthy females. But in truth they are I simply developed in the female ; for in every breed each detail Q 2 228 The Descait of Man. Pakt n. in the structure of the spur is transmitted through tlie 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 de- velopment of characters in the female and of transference to the , male, is less frequent ; it wiU therefore be well to give one strik- . ing instance. With bees the pollen-collecting apparatus is used j by the female alone for gathering pollen for the larvae, yet in | most of the species it is partially developed in the males j to whom it is quite useless, and it is perfectly developed | in the males of Bombus or the humble-bee.®* As not a j single other Hymenopterous insect, not even the wasp, which is closely allied to the bee, is provided with a pollen-coUecting 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 multiphed by self-division. 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 i they were derived, depends on their aflinity for, and imion i with other units or ceils previously developed in the due order of growth. Inheritance at corresponding Periods of Life. — This tendency is weU 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 re- appear in the offspring at the same advanced age. When devia- tions from thia 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,®® I will ” H. Miillcr, ‘ Anwendung der ” ‘ The Variation of Animah Darwin’sehen Lchre,’ &c. Verh. and Plants under Donie.stication, d, n. V. Jahrg. xxix. p. 42, vol. ii, 1868, p. 75. In the la*t Chap. VIII. Sexual Selection. 229 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 down-covered chickens, the young birds in their first true plumage, and the adults differ greatly from one another, as well as from their coromon parent-form, the Qallus hankiva; 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 plu- mage, “ 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.®^ Hence in this breed variations have occurred at, j 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 advanctug 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 I four times; and these modifications of plumage are regularly transmitted. Inheritance at corresponding Seasons of the Year. — With n.nima.ig 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 arctic animals which becomes thick and white during the winter. Many birds acquire bright ) colours and other decorations during the breeding-season alone. ‘ Pallas states,®’ that in Siberia domestic cattle and horses become 1 lighter-coloured during the winter ; and I have myself observed, ' and heard of similar strongly marked changes of colour, that is, from brownish cream-colour or reddish-brown 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 I chapter but one, the provisional hypothesis of pangenesis, above alluded to, is fully explained. These facts are given on the high authority of a great breeder, 1 Mr. Teebay ; see Tegetmeier’s ‘ Poul- try 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 Ani- mals,’ Sic., vol. i. pp. 160, 249 ; vol. ii. p. 77. ‘ Nov!e species Quadrupedum e Glirium ordine,’ 1778, p. 7. On the transmission of colour by the horse, see ‘ Variation of Animals, &o., under Domestication,’ vol. i. p. 51. Also vol. ii. p. 71, for a gene- ral discussion on ‘ Inheritance ns limited by Sex.’ 230 The Descoit of Man. Pakt IL 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 age or sex. Inheritance as Limited by Sex. — 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 tortoise-shell, the corresponding colour in the males being rusty-red. 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 sub-breeds of the fowl in which the males can hardly be distinguished from one another, whilst the females differ con- siderably in colour. The sexes of the pigeon m the parent-species do not differ in any external character ; nevertheless, in certain domesticated breeds the male is coloured differently from the female.®® 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 long-continued selection by man, the slight differences between the sexes are wholly due to the form of inheritance wliich has ])revailed ; for they have arisen, not from, but rather in opposi- tion to, the wish of the breeder. Most of our domestic races have been formed by the accumula- tion 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 tmder nature analogous cases are Dr. Chapuis, ‘ Le Pigeon Voya- geur Beige,’ 1865, p. 87. Boitard ct Corbie, ‘ Les Pigeons de Volifcre.’ &c., 1824, p. 173. See, also, on similar differences in certain breeds at Modena, ‘ Le variazioni dei Colombi domestici,’ del Paolo Bo- nizzi, 1873. 1 Chaf. VIII. Sexual Selection 231 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 tail-plumes 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 sub- breeds of the fowl in which the hens acquire spui's whilst young ; or, as in certain Polish sub-breeds, in which the females, as there is reason to believe, originally acquired a crest, and sub- sequently transferred it to the males. All these cases are in- teUigible on the hypothesis of pangenesis ; for they depend on the gemmules of certain parts, although present in both sexes, becoming, through the influence of domestication, either dormant or developed in either sex. 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 long-continued selection make a breed, in which the males alone should be of this tint, whilst the females remained imchanged ? I will here only say, that this, though perhaps not impossible, would be extremely difficult; for the natural result of breeding from the pale-blue males would be to change the whole stock of both sexes to this tint. If, how- ever, 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, per- haps impossible.®’ Since the publication of the perienced a breeder as Mr. Teget- first edition of this work, it has meier. After describing some cu^ been highly satisfactory to me to rious cases in pigeons, of the trans- find the following remarks (the mission of colour by one sex alone. Field,’ Sept. 1872) from so ex- .and the formation of a sub-breed 232 The Descent of Man. Part IL- On the Relation between the Period of Development of a Character and its Transmission to one Sex or to both Sexes. — Why certain characters should be inherited by both sexes, and other charao- ters 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 sub-breeds of the pigeon, black striae, though transmitted through the female, should be deve- loped in the male alone, whilst every other character is equally transferred to both sexes. Why, again, with cats, the tortoise- shell colour should, with rare exceptions, be developed in the female alone. The very same character, such as deficient or su- pernumerary digits, colour-blindness, &c., 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.^® Although we are thus ignorant, the two following rules seem often to hold good — that 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 as it has an important bearing on sexual selection, I must here enter into lengthy and somewhat intricate details. 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 gamed. 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 thus becoming developed, than with those of the opposite sex. 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. 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 “ BO, he was in ignorance of these “ facts that I have related ; but it “ is remarkable how very closely “ he suggested the right method of “ procedure.” References are given in my Variation of Animals under Domos- tication," vol. ii. p. 72. Chap. VIII. Sexual Selection. 233 amphibians, and fishes ; also with many crustaceans, spiders, and some few insects, such as certain orthoptera and hbeUulse. In aU these cases the variations, through the accumulation of which the male acquired his proper masculine characters, must have occmTed 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 i have transferred their characters to their offspring whilst young. I There are, moreover, many animals, in which the two sexes closely [ resemble each other, and yet both differ from their young ; and j here the characters of the adults must have been acquii’ed late in ) hfe ; nevertheless, these characters, in apparent contradiction to I our rule, are transferred to both sexes. We must not, however, overlook the possibihty or even probability of successive varia- tions 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 ocem-ring 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 hfe 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 result. An excellent case for investigation is afforded by the Deer b family. In all the species, but one, the horns are developed [I only in the males, though certainly transmitted through the B females, and capable of abnormal development in them. In the i reindeer, on the other hand, the female is provided with horns ; so that in this species, the horns ought, according to our rule, I to appear early in life, long before the two sexes are mature I and have come to differ much in constitution. In all the ft other species the horns ought to appear later in life, which 234 The Descent of Man. Part IL would lead to tlieir 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 honjs, 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.’*® 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 structui-e, developed at a most unusually early age in one species of the family, and likewise common to both sexes in this one species alone. 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, kir. 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 closely-allied species, the eland {Ant. areas), 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, con- sidering the size ultimately attained by them; whilst m 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 prong-horned antelope,^® 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 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 head- forester to the Marquis of Breadal- bane. In regard to Fallow-deer, I have to thank Mr. Eyton and others for information. For the Cervus aloes of N. America, see ‘Land and Water,’ 1868, pp. 221 and 254 ; and for the C. Virginianus and strongyluceros of the same con- tinent, see J. D. Caton, in ‘ Ottaw.a Acad, of N.at. Sc. 1868, p. 13. For Cervus Eldi of Pegu, see Lieut. Beavan, ‘Proc. Zoolog. Soc.’ 1867, p. 762. Antilocapra Americana. I have to thank Dr. Canfield for informa- tion with respect to the horns of the female : see also his paper in ‘ Proc. Zoolog. Soc.’ 1866, p. 109. Also Owen, ‘Anatomy of Vertebr.ates,’ vol. iii. p. 627. Chap. VIII. Sexttal Selection. 235 we do know with respect to the horns of deer, cattle, &o., those of the prong-horned 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.^^ 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 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 occasionally produced. Dr. W. Marshall has lately made a special study of the pro- tuberances so common on the heads of bh-ds,^® and he comes to the following conclusion ; — that with those species in which they are confined to the males, they are developed late in hfe; whereas with those species in which they are common to i the two sexes, they are developed at a very eai’ly period. This is j certainly a striking confirmation of my two laws of inheritance. 1 In most of the species of the splendid family of the Pheasants, the males differ conspicuously fi’om 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 ear-tufts 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 ■“ I have been assured that the horns of the sheep in North Wales can always be felt, and are some- times 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. <2 I am greatly indebted to Prof. Victor Carus for having made en- quiries 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. Win wood 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 oc- curred at a later period oi life than in Welsh sheep, in which both sexes are horned. ‘ Ueber die knochernen Sch'ddel- hocker der Vogel’ in the ‘Nieder- landischen Archiv fiir Zoologie,’ Baud I. Heft 2, 1872. 236 The Descent of Man. Part IT. 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.^^ The male and female Peacock differ conspicuously from each other in almost every part of their plumage, except in the elegant head-crest, 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 wild-duck 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 tail-feathers and other ornaments of the male are developed later.'*® Between such extreme cases of close sexual resemblance and wide dissunilarity, 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 In the common peacock (Pa«o cristatus) the male alone possesses spurs, whilst both sexes of the Java Peacock (P. muticus) offer the un- usual 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 pre- vious year, of both species, com- pared on April 23rd, 1869, there was no difference in the develop- ment of the spurs. The spurs, however, were as yet represented merely by slight knobs or eleva- tions. I presume that I should have been informed if any difference in the rate of development had been observed subsequently. 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 develop- ment 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 jJergtts cu- cullatus we have, however, a case of this kind : the two sexes differ con- spicuously in general plumage, and to a considei’able degree in the speculum, which is pure white in the male and greyish-white in the female. Now the young males at first entirely resemble the females, and have a greyish-white speculum, which becomes pure white at an earlier age than that at which the adult male acquires his other and more strongly-marked sexual dif- ferences : see Audubon, ‘ Ornitho- logical Biography,’ vol. iii. 1835, pp. 249-250. Chap. VIII. Sexual Selection. 237 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 fii’st appear ; for with the Orthoptera, which assume their adult state, not by a single metamorphosis, but by a suc- cession 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, re- latively 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 super- numerary digits, and the absence of certain phalanges, must be determined at an early embryonic period — the tendency to profuse i bleeding is at least congenital, as is probably colour-blin^ess — ; yet these peculiarities, and other similar ones, are often Limited i in their transmission to one sex; so that the rule that I characters, developed at an early period, tend to be trans- 1 mitted 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 i 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 sexually-limited diseases, Ave know too little of the period at which they originate, to draw any safe conclusion. Gout, however, seems to faU under our rule, for it is generally caused by intemperance during manhood, and is transmitted from the father to Ids sons in a much more marked manner than to his daughters. In the various domestic breeds of sheep, goats, and cattle, the males differ from their respective females in the shape or develop- ment of their horns, forehead, mane, dewlap, tail, and hump on the shoulders ; and these peculiarities, in accordance with oui- 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 deer-hound, 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 in- creased size being transmitted to his male offspring alone. On the other hand, the tortoise-shell colour, which is confined to female cats, is i^uite distinct at birth, and this case violates the rule. There is a breed of pigeons in which the males alone axe 238 The Descent of Man. Part II. 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 sub-breeds of the pigeon, described by Neumeister,^® 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 Canary-bird, namely the London Prize, offers a nearly analogous case. With the breeds of the Fowl the inheritance of various charac- ters 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 coloim from the female, as well as from the wild parent-species, he differs also from the young male, so that the newly-acqmred characters must have appeared at a rather late period of hfe. 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 so-called Cuckoo sub-breeds of the fowl, in which the feathers are transversely pencilled with dark stripes, both sexes and the chickens are colorrred 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 ‘DasGanzo der Taubenzucht,’ puis, ‘ Le pigeon voyageur Beige,’ 1837, s. 21, 24. For the case of 1865, p. 87. the streaked pigeons, see Dr Cha- Ohap. VIII. Sexual Selection. 239 do the sexes of the aboriginal parent-species ; yet they acquire then- characteristic plumage late in Life, for the chickens are ! distinctly pencilled. With respect to other characters besides colour, in the wild-parent species and in most of the domestic breeds, the males alone possess a well-developed 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 trans- mitted 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 1 supports the crest is partially developed even before the chickens are hatched, and the crest itself soon begins to grow, though at I first feebly;*^ and in this breed the adults of both sexes are I 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 transmission — for example, the striking fact of I the early growth of the horns in the reindeer, in which both ; sexes bear horns, in comparison with their much later growth I in the other species in which the male alone bears horns — we I 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. Summary and concluding remarks, — From the foregoing dis- i cussion 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 i periodically at the same season of the year, in which they first For full particulars and re- I ferences on all these points respect- I mg the several breeds of the Fowl, I see ‘ V.iriation of Animals and Plants I 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 s.ame work under the head of each species. 240 The Descent of Man. Part 1L 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 degree. "When variations occur late in life in one sex, and are trans- mitted 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 hfe 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 modi- fied, 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 charac- ters of the adult males; and differences of this kind between the old and young males may bo observed in many species of animals. 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 injurious— Chap. YIII. Sexual Selection. 241 as by acquiring bright colours, which would render them con- spicuous to theii’ 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 thi’ough 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 some exposure to danger, and some loss of vital force. 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, I soon lost through intercrossing and accidental deaths. Conse- quently in a state of natm-e, if variations of the above kind chanced 1 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 j 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 ; I more intricate contingencies. Lastly, the females may acquire, and '[apparently have often acquired by transference, characters from ( the male sex. As variations occurring late in Life, and transmitted to one ! sex alone, have incessantly been taken advantage of and accumu- jlated thi’ough sexual selection in relation to the reproduction of ithe species ; therefore it appears, at first sight, an unaccountable fact that similar variations have not frequently been accumu- llated through natm’al 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 irapturing prey or of escaping from danger. Differences of this Irind^ between the two sexes do occasionally occur, especially in the lower classes. But this implies that the two sexes follow iifferent habits in their struggles for existence, which is a rare (circumstance with the higher animals. The case, however, is ■^idely different with the reproductive functions, in which respect (the sexes necessarily differ. For variations in structure which (ire related to these functions, have often proved of value to one fcex, and from having arisen at a late period of life, have been K 242 The Descent of Man. Paut IL 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 i 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 Iw 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. Supplement on the proportional numbers of the two sexes in animals belonging to various classes. 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. Man. — ^In England during ten years (from 1857 to 1866) the average number of children bom 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 Buckingham- shire (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., But- landshii'e (where the annual births average only 739), in 1864 i 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 73^ births during the whole ten years, was as 104'5 to 100 ; that is in the same ratio as throughout England.'*® The proportions are 1 sometimes slightly disturbed by unkno'wn causes; thus Prof. < ‘ Twenty-ninth Annu.il Report In this report (p. xii.) .i speci.il dc- ^ of the Registrar-General for 1866.’ ccnninl t.ihle is given. Chap. YIII. Proportion of the Sexes. 243 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 forty-four 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 biidhs have exceeded the males. In Eussia the average proportion is as high as 108'9, and in Philadelphia in the United States as 110'5 to 100.^“ The average for Europe, deduced by Bickes from about seventy million bu'ths, 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 I being the same as usual, for instance, in Livonia as 104 to lOO.*^® 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 dui'ing birth. But the fact is, that “ for every 100 stfll-born females, we have in several countries I “ from 134'6 to 144'9 still-born males. During the first four or t “ five years of life, also, more male children die than females ; I “ for example in England, during the fii’st year, 126 boys die for I “ every 100 girls — a proportion which in Franco is stiU more f “ imfavourable.”®^ Dr. Stockton-Hough accounts for these facts in part by the more frequent defective development of males I than of females. We have before seen that the male sex is more For Norway and Eussia, see abstract of Prof. Faye’s researches, in ‘ British and Foreign Medico- Chirurg. Review,’ April, 1867, pp. 343, 345. For France, the ‘ An- I nuaire pour I’An 1867,’ p. 213. ' For Philadelphia, Dr. Stockton- : Hough, ‘ Social Science Assoc.’ 1874. For the Cape of Good Hope, Quetelet f as quoted by Dr. H. H. Zouteveen, I in the Dutch Translation of this work (vol. i. p. 417), where much I' information is given on the propor- I tion of the sexes. • *'> In regard to the Jews, see M. I Thury, ‘ La Loi de Production des » Sexes,’ 1863, p. 25. ' “ ‘British and Foreign Medico- 1 Chimrg. Review,’ April, 1867, p. 343. Dr. Stark also remarks (‘Tenth Annual Report of Births, Deaths, &c., in Scotland,’ 1867, p. x-xvili.) that “ These examples may “ suffice to shew that, at almost “ evei-y stage of life, the males in “ Scotland have a greater liability “ to death and a higher death-rate “ than the females. The fact, how- “ ever, of this peculiarity being “ most strongly developed at that “ infantile period of life when the “ dress, food, and genei’al treatment “ of both sexes are alike, seems to “ prove that the higher male death- “ rate is an impressed, natural, and “ constitutional peculiarity due to “ sex alone.” i The Descent of Man. Paht II. 2.U variable in structure than the female; and variations in im- portant 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 still- born males are more numerous ; and, as a highly comjjetent judge, Dr. Crichton Browne,®^ believes, male infants often suffer in health for some years after birth. Owing to this excess in the death- rate of male children, both at birth and for some time sub- sequently, and owing to the exposure of grown men to various dangers, and to their tendency to emigrate, the females in all old-settled countries, where statistical records have been kept,“ are found to preponderate considerably over the males. 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.®* This has been explained by different writers in many different ways, as from the mothers being generally young, from the large proportion of first preg- nancies, &c. But we have seen that male infants, from the largo size of their heads, suffer more than female infants during parturition ; and as the mothers of illegitmiato children must bo 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, &c., their male infants would proportionably suffer. And this probably is the most efficient of aU the causes of the proportion of males to females born alive being less amongst illegitimate children than amongst tho 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 ‘ West Eiding Lunatic Asylum lleports,’ vol. i. 1871, p. 8. Sir J. Simpsou has proved that the head of the male infant exceeds that of the female by 3-8 ths of .an inch in circumference, and by l-8th in transverse diameter. Quetelet has shewn that woman is born smaller than man ; see Dr. Duncan, ‘ Fe- cundity, Fertility, Sterility,’ 1871, p. 382. With the savage Guaranys of Paraguay, according to the accurate Azara (‘ V oy.ages d.ans I’Amerique merid.’ tom. ii. 1809, p. 60, 179), the women are to the men in the proportion of 14 to 13. “ Babbage, ‘ Edinburgh Journal of Science,’ 1829, vol. i. p. 88 ; also p. 90, on still-born children. On illegitimate children in Englaud, see ‘ Report of Registrar-General for I860,’ p. IV, Chap. YIU. Proportion of the Sexes. 245 we have the cmious fact that we may attribute the more frequent deaths of male than female infants^ especially amongst the illegitimate, at least in part to sexual selection. It has often been supposed that the relative age of the two parents determines the sex of the offspring ; and Prof. Leuckart“ has advanced what he considers sufficient evidence, with respect to man and certain domesticated animals, that this is one impor- tant 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 observa- tions discountenance this belief. According to Dr. Stockton- Hough,®® the season of the year, the poverty or wealth of the parents, residence in the country or in cities, the crossing of foreign immigrants, &c., 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®'^ 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 race- horse, 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 selection has come into play in determining the result. Horses. — Mr. Togetmeier has been so kind as to tabulate for me from I the ‘ Racing Calendar ’ the births of race-horses during a period of I twenty-one years, viz., from 1816 to 1867; 1849 being omitted, as no I returns were that year published. The total births were 25,560,®® con- > sistiug of 12,763 males and 12,797 females, or in the proportion of 99'7 I maliiS to 100 females. As these numbers are tolerably large, and as ' they are drawn from all parts of England, during several years, we may I with much confidence conclude that with the domestic horse, or at ; least with the race-horse, the two sexes are produeed in almost equal I numbers. The fluctuations in the proportions during successive year.s ' ®® Leuckart (in Wagner ‘ Hand- wortcrbuch der Phys.’ B. iv. 1853, ' t. 774. ' ®“ Social Science Assoc, of Phila- i dclphia, 1874. ’ ®‘ ‘ Anthropological Review,’ • April, 1870, p. cviii. • During eleven years a record • was kept of the number of mares « which proved barren or prematurely I slipped their foals ; and it deserves notice, as shewing how infertile these highly-nurtured and rather closely-interbred animals have be- come, that not far from' one-third of the mares failed to px’oduce living foals. Thus during 1866, 809 male colts and 816 female colts were born, and 743 m.ares failed to produce offspring. During 1867, 836 males and 902 females were born, and 794 mares failed. 246 The Descent of Man. Past II, are closely lilio those which occur with mankind, when a small and thinly-populated 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 Kegistrar’s Keport for 1866. Dogs. — During a period of twelve years, from 1857 to 1868, the births of a large number of greyhoimds, 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 HOT 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 HOT to 100 is probably nearly correct in the case of the greyhound, but whether it would hold with other domesticated breeds is iu 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 impression on the mind. Sheep. — 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 con-vinced that a larger proportion of males than of females die during the first year or two. Therefore tho 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 tho 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 black-faced sheep bred in Scotland, I have received returns from six breeders, two of them on a large scale, chiefly for the years 1867-1869, 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 tho age of castration the females are certainly iu excess of the males, but probably this would not hold good at birth.^" Of Cattle I have received returns from nine gentlemen of 982 births, too few to be trusted ; these consisted of 477 bull-calves and 505 cow- I am much indebted to Mr. Cupples for having procured for mo the above returns fi-om Scotland, ns well as some of the following re- turns on cattle. Mr. K. Elliot, of Laighwood, first called my atten- tion to the premature deaths of the males, — a statement subsequently conlirmed by Mr. Aitchison and othci-s. To this latter gentleman, and to Mr. Payan, I owe ray thank* for large returns as to sheep. Chap. VIII. Proportioji of the Sexes. 247 calves : i.e., in the proportion of males to 100 females. The Eev. W. D. Fox informs me that in 1867 out of 31 calves bom 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 Balhits for many years, and has noticed that a far greater number of bucks are produced than does. But estimations are of little value. 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. E. Elliot, of Laighwood, informs me that a rat-catcher 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 liimself subsequently examined some hundred old ones, and found the statement tme. Mr. P. 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 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®* {Kobm ellipsiprymnus'), remarks, that in the herds of this and other species, the males are few in number I compared with the females : the natives believe that they are born in 1 this proportion ; others believe that the younger males are expelled I from the herds, and Sir A. Smith says, that though he has himself I never seen herds consisting of young males alone, otliers affirm tliat 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. BIEDS. With respect to the Fcywl, I have received only one account, namely, that out of 1001 chickens of a highly-bred stock of Cochiris, 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. Teget- meier 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 sn.tnA nest, and seldom two hens ; moreover, the hen is generally the weaker of the two, and more liable to perish. With respect to birds in a state of nature, Mr. Gould and others®® 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 wUd birds, and ho inlorms Mr. Jenner Weir that four or five males to one femalo aro generally produced. An experienced observer remarks.®^ ®® Bell, ‘ History of British Quad- rupeds,’ p. 100. ®‘ ‘ Illustrations of the Zoology of S. Africa,’ 1849, pi. 29. ®® Brehm (‘ Illust. Thierleben,’ B. iv. s. 990) comes to the same con- clusion. ®® On the authority of L. Lloyd, ‘Game Birds of Sweden,’ 1867, rp. 19, 132. 248 The Descent of Man. Paet II. that in Scandinavia the broods of tlie capercailzie and black-cock contain more males than females ; and that with the Dal-ripa (a kind of ptarmigan) more males than females attend the Ze/cs 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. Prom various facts given by White of Selborne,'* it seems clear that the males of the partridge must be in considerable e.vcess 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 largo numbers of ruffs (Machetes pugnax), was told that the males are much the more numerous. This same naturalist has also enquired foj- me from the birdcatchers, who annually catch an astonishing number of various small species alive for the London market, and he was un- hesitatingly answered by an old and trustworthy man, that with the chafidnch 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.“ 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 humming-birds in Central America, and he 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 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 chafBnch 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.”®' So again with the Quiscalus major, Mr. G. Taylor®® says, that in Florida there were “ very few females in proportion to the males,” whilst in Honduras the proportion was the other way, the species there having the character of a polygamist. ”■* ‘Nat. Hist, of Selborne,’ letter xxix. edit, of 1825, vol. i. p. 139. ®® Mr. Jenner Weir received similar information, on making en- quiries during the following year. To shew the number of living chaf- finches caught, I may mention that in 1869 there was a match between two e.vperts, 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. ®® ‘ Ibis,’ vol. ii. p. 260, as quotc l in Gould’s ‘ Trcchilidaj,’ 1861, p* 52. For the foregoing proportions, I am indebted to Mr. Salvin for a table of his results. ®' ‘Ibis,’ 1860, p. 137; and 1S67, p. 369. »" ‘Ibis,’ 1862, p. 137. CuAP. viir. Proportion of the Sexes. 249 FISH. ■VVi& Fish the proportional Bumbers 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."® Infertile females might readily be mistaken for males, as Dr. Gunther has remarked to me in resaa'd 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 largo number of males would escape from the same net by which the females were caught. M. Carbonnier,^® who has especially attended to the natural history of the pike {Esox lucim), 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. E. Buist, the superin- tendent 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 spawning-beds.” ‘‘ 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.'- ' Mr. H. Lee informs me that out of 212 trout, taken for this purpose in k Lord Portsmouth’s park, 150 were males and 62 females. ' The males of the Cyprinidm likewise seem to be in excess ; but r several members of this Family, viz., the carp, tench, bream and I minnow, appear regularly to follow the practice, rare in the animal i kingdom, of polyandry; for the female whilst spawning is always attended by two males, one on each side, and in the case of tire bream by three or four males. This fact is so well known, tliat 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 spawniirg-beds the males are ten times as numerous as the females ; when a female comes amongst the Leuckart quotes Bloch (Wag- tier, ‘ Handworterbuch der Phys.’ B. iv. 1853, s. 775), that with fish there are twice as many males .as females. Quoted in the ‘Farmer,’ March 18, 1869, p. 369. '* ‘The Stormontfield Piscicul- tural Experiments,’ 1866, p. 23. 'I’he ‘Field’ newspaper, June 29th, 1867. ‘ Land and Water,’ 1868, p. 41, 250 The Descent of Man. Part II, 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.” INSECTS. In this great Class, the Lepidoptera almost alone afford means for judgmg 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 silk-moths might have kept an exact record, but after writing to France and Italy, and consulting various treatises, I cannot rind 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 silk-moth (Bombyx cynthia), the males greatly preponderate in the first, whilst in the second the two sexes are nearly equal, or the females rather in excess. In regard to Butterflies in a state of nature, several observers have been much struck by the apparently enormous proponderance of the males.’’'* Thus Mr. Bates,’® 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 propor- tion 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. E. Trimen found the males in excess in 19 species 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.” 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 per- haps offer an exception. Mi-. Wallace states that the females of Omifhoptera crcesus, in the Malay archipelago, are more common and more easily caught than the males ; but this is a rare butterfly. I may Yarrell, ‘ Hist. British Fishes,’ vol. i. 1826, p. 307 ; on the Cyprinus carpio, p. 331 ; on the Tinea vulgaris, p. 331 ; on the Abramis brama, p. 33G. See, for the minnow {Leu- ciscus phoxinus'), ‘ Loudon’s Mag. of Hat. Hist.’ vol. v. 1832, p. 682. ’■* 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. ’® ‘The Naturalist on the Ama- zons,’ vol. ii. 1863, p. 228, 34r7- Four of these cases are given by Mr. Trimen in his ‘ Rhopalocera Africa: Australis.’ ” Quoted by Trimen, ‘ Transact. Ent. Soc.’ vol. -7. part iv. 1866, p. 330. ’* ‘Transact. Linn. Soc.’ vol. szv. p. 37. Chap. VITI. Proportion of the Sexes. 251 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 ™^hen this subject of the proportional numbers of the sexes of insects was brought before the Entomological Society,” 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 knomi to occur with most Lepidoptera, as well as with other insects. So that, as M. Personnat remarks, the males of the domesticated Bombyx Tamamai, are useless at the begin - nino- of the season, and the females at the end, from the want of mates.®“ I cannot, however, persuade myself that these causes suffice to explain the great excess of males, in the above cases of certain butter- fiies 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, ho thought that the males were ten times as numerous as the i females, but that since he has reared them on a large scale from the 1 caterpillar state, he is convinced that the females are the more I numeroits. Several entomologists concur in this view. Mr. Double- day, however, and some others, take an opposite view, and are con- vinced 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 f from the cocoon, and in some cases their frequenting more open I stations, other causes may be assigned for an apparent or real difference ; in the proportional numbers of the sexes of Lepidoptera, when cap- I tured in the imago state, and when reared from the egg or caterpillar 1 state. I hear from Professor Canestrini, that it is believed by many ■ breeders in Italy, that the female caterpillar of the silk-moth sirffers more from the recent disease than the male ; and Dr. Staudinger informs mo that in rearing Lepidoptera more females die in the i cocoon than males. With many species the female caterpillar is larger than the male, and a collector would naturally choose the finest I specimens, and thus unintentionally collect a Isirger number of females. I Three collectors have told me that this was their practice ; but Dr. Wallace is sure that most collectors take all the specimens which they I can find of the rarer kinds, which alone are worth the trouble of i rearing. Birds when surrounded by caterpillars would probably ' devour the largest ; and Professor Canestrini informs me that in Italy I some breeders believe, though on insufficient evidence, that in the first I broods of the Ailanthus silk-moth, the wasps destroy a larger number of ' the female than of the male caterpillars. Dr. Wallace further remarks 1 that female caterpillars, from being larger than the males, require I more time for their development, and consume more food and mois- ' ture ; and thus they would bo exposed during a longer time to r danger from ichneumons, birds, &c., and in times of scarcity would perish in greater numbers. Hence it appears quite possible that ‘ Proc. Entomolog. Soc,’ Feb. ‘ Proc. Eat. Soc.’ 3rd series, vol. 17th, 18C8. 1867,1.487. Quoted by Dr. Wallace in V 252 The Descent of Man. Pakt it. in a state of nature, fewer female Lepidoptera may reach maturity than_ males ; and for our special object we are concerned with their relative numbers at maturity, when the sexes are ready to propagate their kind. 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 ElacMsta 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, M. 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.®^ Mr. Doubleday has called my attention to M. Staudinger’s list of Lepidoptera, which gives the prices of the males and females of 300 species or well-marked varieties of butterfiies (Ehopalocera). The prices for both sexes of the very common species are of com’se the same ; but in 114 of the rarer species "they difi'er ; the males being in all cases, excepting one, the cheaper. On an average of the prices of the 113 species, ihe 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 Ihe 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 diflerence in the prices of the tw'O 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. M itl) respect to specimens reared from the caterpillar-state. Dr. Staudinger lielieves, as previously stated, that a greater number of females than of males die whilst confined in the cocoons. Ho adds that with certain species one sex seems to preponderate over the other during certain years. Of direct observations on the sexes of Lepidoptera, reared either Blanchard, ‘ Me'tamoridioses, ‘ Lepidopteren - Doubleften Mocurs des Insccteo,’ !I8C8, pp. 2 Listc,’ Berlin, Eo. x. 186G. 22U Chap. VIII. Pi'oportion of the Sexes. 253 i from eggs or caterpillai-s, I have received only the few following cases ; — I Males. Females. The Eev. J. Hellins®’ of Exeter reared, during 1868, \ images of 73 species, which consisted of . . . / Mr. Albert Jones of Eltham reared, daring 1868,1 imagos of 9 species, which consisted of . . . / During 1869 he reared imagos from 4 species, con-1 sisting of / Mr. Buckler of Emsworth, Hants, during 1869,1 reared imagos from 74 species, consisting of. ./ Dr. Wallace of Colchester reared from one brood ofl Bombyx cynthia / Dr. Wallace raised, from cocoons of Bombyx Pernyil sent from China, during 1869 j Dr. Wallace raised, during 1868 and 1869, from twol lots of cocoons of Bombyx yama-mai . . . j Total 153 137 159 126 114 112 180 169 52 48 224 123 52 46 934 761 I So that in these eight lots of cocoons and eggs, males were produced I 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 dkection, I infer that with most species of Lepidoptera, : the mature males generally exceed the females in number, whatever [ the proportions may be at their first emergence from the egg. With reference to the other Orders of insects, I have been able to collect very little reliable information. With the stag-beetle (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 Elateridm, the males are said to be much more numerous than the females, and “ two or three are often found united with one female ' “ so that here polyandiy seems to prevail.” With Siagonium (Staphy- linidee), 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 Tomiem villosus are so common ns to be a plague, whilst the males are so rare ns to be hardly known. ' This naturalist has been so kind as to send me some results I from former years, in which the females seemed to preponderate ; but so many of the figures were I estimates, that I found it impossible to tabulate them. Gunther’s ‘ Record of Zoo- logical Literature,’ 1867, p. 260. On the excess of female Lucanus, ibid.»p. 250. On the males of Luca- nus in England, Westwood, ‘ Modern Class, of Insects,’ vol. i. p. 187. On the Siagonium, ibid. p. 172. 254 TJie Desce7it of Man. Part II. It is hardly worth while saying anjdhing 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.®'* In all the gall-making Cynipidm known to Mr. Walsh, the females are four or five times as numerous as the males ; and so it is, as he infonns me, with the gall-making Cecidomyiias (Diptera). With some common species of Saw-flies (Tenthredinae) Mr. F. Smith has reared hundreds of specimens from lar%’ae of all sizes, but has never reared a single male : on the other hand, Curtis says,*® 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 Miiller,®^ 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 breeding season 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. Miiller 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 MiiUer 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 : Kbrte,®* however, says that out of 500 locusts which ho 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 Hetairina, 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.®® In England, Mr. MacLachlan has captured hundreds of the female Apatania muUehris, but has never seen the male; and of Boreus liyemalis only four or five males hare been seen here.®® With most of these species (excepting the Tenthredinro) 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 proportion of the two sexes. In the other Classes of the Articulata I have been able to collect still Walsh, in ‘ The American En- tomologist,’ vol. i. 1869, p. 103. F. Smith, ‘ Kecord of Zoological Literature,’ 1867, p. 328. ‘ Farm Insects,’ pp. 45-46. ‘ Anwendung der Darwinschen I.ehre Verh. d. n. V. Jahrg. xxiv.’ ‘ Die Strich, Zug oder Wnn- derheuschrecke,’ 1828, p. 20. ®® * Observations on N. American Neuroptera,’ by II. Hagen and B. D. Walsh, ‘ Proc. Ent. Soc. Phila- delphia,’ Oct. 1863, pp. 168, 223, 239. ®® ‘ Proc. Ent. Soc. London,’ Feb. 17, 1868, Chap. VIII. Proportion oj the Sexes. 255 less information. With Spiders, Mr. Blackball, 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.*’^ The small size of the males in comparison with the females (a peculiarity which is some- times carried to an extreme degree), and theh widely different appear- ance, may account in some instances for their rarity in collections.^^ Some of the lower Crustaceans are able to propagate their kind asexually, and this wiU account for the extreme rarity of the males : thus Von Siebold carefully examined no less than 13,000 specimens of Apus from twenty-one localities, and amongst these he found only 319 males. With some other forms (as Tanais and Cypris), as Fritz Miiller informs me, there is reason to believe that the males are much I shorter-lived than the females ; and this would explain their scarcity, I 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 1 Diastylidffl 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 1 of the higher Brazilian crabs, namely a Gelasimus, Fritz Miiller I found the males to be more numerous than the females. According I to the large experience of Mr. G. Spence Bate, the reverse seems to be the case with six common British crabs, the names of which he t has given me. The proportion of the sexes in relation to natural selection. There is reason to suspect that in some cases man has by selection indirectly influenced his own sex-producing 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 Jlr. Wright of Yelderslcy 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 short-horn cattle. Col. Marshall has recently found on careful examination that the Todas, a hill-tribe of India. Another great authority with 0. P. Cambridge, as quoted respect to this class. Prof, Thorcll of " ' " ' (Jpsala (‘ On European Spiders,’ 1869-70, part i. p. 205) speaks as if female spiders were generally com- moner than the males. ” See, on this subject, Mr. IS Science, as ‘ Quarterly Journal of 1868, p. 429. ‘ Beitrilge zur Parthenogenesis,’ p. 174. »* ‘The Tof.-w,’ 1873. on. 100 111, 194, 196. The Descent of Man. Part IL 256 consist of 112 males and 84 females of all ages— that 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 childi-en bom 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 tlie purpose of dlustra- “ tion 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 thi-ee daughters. The first " mother, following the tribal custom, destroys four daughters “ and preserves two. The second retains her six sons. The third “ kiUs 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 than daughters.” That this result would follow from the above fonn of infanticide seems almost certain ; that is if we assume that a sex-producing tendency is inherited. But as the above numbers are so ex- tremely 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 JIi’. Fenton®^ states that he “ has met with instances of women who have de- stroyed four, six, and even seven chilcben, 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 Zea- landers, as with the Todas, male births are considerably in excess. Ml-. 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 bo demonstratively fixed, “ it is quite clear that this coui-se of decrease was in full opera- “ tion during the years 1830 to 1844, when the non-adult “ 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 ““ ‘ Aborigiaal luhabitants of New Zealand ; Government Report,’ 1859. p. 36. Chap. VIII. Proportion of the Sexes. 257 are not lai’ge, 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 I30'3 males to 100 females. But during this same year, and in certain limited districts, the numbers were ascertained vuth 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 non-adult males within the same district were found to be 178, and the non-adult 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 non-adidt males in one district were 281, and the non-adidt females only 194, that is in the ratio of 144'8 males to 100 females. 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,®® and as I have been informed by Bishop Staley and the Eev. Mr. Goan. Nevertheless, another apparently trustworthy writer. Mi-. Jarves,®^ whose observations apply to the whole archiirelago, 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 “ usefrd 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- four teen years in Kauai and under eighteen in Oahu was 1797, and of females of the same ages 1429 ; and hero wo have the ratio of 125-75 males to 100 females. In a census of all the islands in 1850,®® the males of all ages ‘N.nrrative of a Tour through This is given in the Rev. H. T. Hawaii,’ 1826, p. 298. Clieevcr’s ‘ Life in the Sandwich I»- ‘ History of the Sandwich lands,’ 1851, p. 277. Islands,’ 1843, p. 93. 258 The Descent of Man. Part IT. 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 half-castes) to females, is as 125-36 to 100. It must be borne in mind -that all these returns for the Sand-wich Islands give the proportion of living males to living females, and not of the births ; and judging from all ci vilised countries the proportion of males -would have been considerably higher it the numbers had referred to births.®^ From the several foregoing cases -we have some rea.son to believe that infanticide practised in the manner above explained, tmids to make a male-producing race ; but I am far from sup- posing 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 unkno-wn la-w leading to this result in decreasing races, -which have already become some-what infertile. Besides the several causes previously Dr. Coulter, in describing (‘ Journal R. Geograph. Soc.,’ vol. ■V, 1835, p. 67) the state of Cali- fornia about the year 1830, says that the natives, reclaimed by the Spanish missionaries, have nearly all perished, or are perishing, al- though -well treated, not driven from their native land, and kept from the use of spirits. He at- tributes 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 “ in- “ fanticide, properly so called, is “ not common, though very fre- “ quent recourse is had to abor- “ tion.” If Dr. Coulter is correct about infanticide, this case cannot be advanced in support of Col. 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 habits of life. 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 ot the proportion of the sexes in any breed, excepting greyhounds, and there the male births are to the female as 110-1 to 100. Now from enquiries made from many breeders, it seems that the females arc in some respects more esteemed, though otherwise troublesome ; and it does not appe.ar that the female puppies of the best-bred dogs arc systematically destroyed more than the males, though this does sometimes take place to a limited extent. There- fore I am unable to decide whether we can, on the above principles, ac- count for the preponderance of male births in greyhounds. On the other hand, we have seen th.at with horses, cattle, and sheep, which are loo valuable for the young of either sex to be destroyed, if there is any difference, the females are slightly in excess. Chap. VIII. Proportion of the Sexes. 259 alluded to, the greater facility of parturition anongst savages, and the less consequent injury to their male infants, would tend to increase the proportion of live-born 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 com- plication of causes, an indiscriminate though large destruction of either sex would not tend to modify the sex-producing power of the species. With strictly social animals, such as bees or ants, which produce a vast number of sterile and fertile females in compaiison 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 sex-producing tendency would be ulti- mately gained tlnough 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 pre- ponderance of men in the tribe is supposed to be one chief cause of the practice of female infanticide. 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 bo necessary for the fertilisation of the female ; and the males accordingly largely preponderate, but it is by no means obvious how this male-producing 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 s 2 26o Past II. The Descent of Man. seo that the -whole problem is so intricate that it is safer to leave its solution for the future. CHAPTER IX. Seoondaey Sexual Characters in the Lower Classes of THE Animal Kingdom. These characters absent in the lowest classes — Brilliant colours — Mollusca — Annelids — Crustacea, secoudary sexual characters strongly developed ; dimorphism ; colour ; characters not acquired before maturity — Spiders, sexual colours of; stridulation by the males — Jlyriapoda. 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 at- tached 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 each other’s beauty or other attractions, or to feel rivalry. Hence in these classes or sub-kingdoms, such as the Protozoa, Ccelenterata, Echinodermata, Scolecida, secondary sexual cha- racters, 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 oceui’; thus, as I hear from Hr. Eaird, 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 selection. Many of the lower animals, whether hermaphrodites or ivith separate sexes, are ornamented -with the most brilliant tints, or are shaded and striped in an elegant manner ; for instance, many corals and sea-anemones (Actiniie), some jelly-fish (Medusai, Porpita, &c.), some Planarise, many star-fishes, Ecliini, Ascidians, &c. ; but we may conclude from the reasons already indicated, namely the union of the two sexes in some of these animals, the permanently aflSxed 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. Chap. IX. Sexual Selection. 261 It should be borne in mind that in no case have we suffi- cient evidence that colours have been thus acquired, ex- cept where one sex is much more brilliantly or conspicuously coloui-ed 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 indivi- duals, almost always the males, voluntarily display their attractions before the other sex ; for we cannot beheve 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 ahke, if then* colours are plainly analogous to those of one sex alone in certain other species of the same group. 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 protec- tion ; 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 Meduste, or jelly-fishes, is of the highest service to them as a protection; but when we are reminded by Hiickel that not only the medusae, but many floating mollusca, crustaceans, and even small oceanic fishes partake of this same glass-hke 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^ that the bright tints of certain sponges and ascidians serve as a protection. Conspicuous colours are likewise beneficial to many am'mals as a warning to their would-be 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 or 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 acqirircd 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 Eolidaj (naked sea-slugs) is chiefly clue to the biliary glands * ‘Archives de Zooiog. E-vpiSr.,’ Oct. 1872, p. 563. 262 The Descent of Man. pAni- U. boing seen through the translucent integuments — this beauty being probably of no service to these animals. The tints of the decaying leaves ia 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 snbstances closely analogous to natural organic compounds have been recently fonned 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 laboratory of living organisms. The sub-kingdom of the Mollusca. — 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 Lamelhbranchiata, 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. Bnt 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 snfficient 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 land-snails, the pairing is preceded by courtship; for these animals, though hermaphrodites, are compelled by their structure to pair together. Agassiz remarks,^ “ Quiconque a eu I’occasion “ d’observor les amours des lhna5ons, ne saurait mettre en doute “ la seduction deployee dans les mouvements et les allures qui “ proparent et accomplissent le double embrassement de ces “ hermaphrodites.” These animals appear also susceptible of some degi’ee of permanent attachment : an accurate observer, ® ‘ Do I’Espfece et de la Class.’ &c., 1869, p. 106. Chap. IX. Molluscs. 263 Mr. Lonsdale, informs me that he placed a pair of land-snails, {Helix ‘pomatia), one of which was weakly, into a small and ill- proTided 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 well-stocked garden. Mr. Lonsdale concluded that it had deserted its sickly mate; but after an absence of twenty-four hours it retui’ned, and apparently communicated the result of its successful exploration, for both then started along the same track and disappeared over the wall. Even in the highest class of the Mollusca, the Cephalopoda or cuttlefishes, 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 sui’prising circumstance, as these animals ix)ssess highly-developed sense-organs and have considerable mental powers, as will be admitted by every one who has watched their artful endeavoims to escape from an enemy.® 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 sucking-discs to the female, lives for a time an independent life. So completely does the cast-off arm resemble a separate animal, that it was described by Cuvier as a parasitic worm rmder the name of Hectocotyle. But this marvellous structure may be classed as a primary rather than as a secondary sexual character. Although Avith the Mollusca sexual selection does not seem to have come into play; yet many univalve and bivalve shells, such as volutes, cones, scallops, &c., are beautifully coloured and shaped. The colom-s 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 sculptm-e of the shell depending on its manner of gi’owth. The amount of light seems to be influential to a certain extent ; for although, as repeatedly stated by Mi-. 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 highly-coloiu-ed than the upper and exposed surfaces.'* In some cases, as with shells instance, the account influence of light on the colours of which I have given in iny ‘Journal a frondescent incrustation, de- ot Researches, 1845, p. 7. posited by the surf on the coast- I have given (‘ Geolog. Obser- rocks of Ascension, and formed by vations on Volcanic Islands,’ 1844, the solution of triturated sea-shells, p. 53) a curious instance of the 264 The Descent of Man. Part II, living amongst corals or briglitly-tinted sea-weeds, the bright colours may serve as a protection.® But that many of the nudi- branch mollusca, or sea-slugs, 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 wliich lives on the green leaves of algae, and is itself bright-gi’een. But many brightly-coloui-ed, white or otherwise conspicuous species, do not seek concealment ; whilst again some equally conspicuous species, as well as other dull-coloured kinds, Live under stones and in dark recesses. So that with these nudi- branch molluscs, colour apparently does not stand in any close- relation to the nature of the places which they inhabit. These naked sea-slugs are hermaphi-odites, yet they pair together, as do land-snails, many of which have extremely pretty shells. It is conceivable that two hermaphi-odites, attracted by each other’s greater beauty, might unite and leave offspring which would inherit their parents’ gi-eater beauty. But with such lowly-organised creatures this is extremely improbable. Nor is it at all obvious how the offspring from the more beautiful pau-s of hermaphrodites would have any ad- vantage over the offspring of the less beautiful, so as to increase in number, unless indeed vigom- 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 brightly-tinted individuals would succeed best and would increase in number; but this would be a case of natural and not of sexual selection. Bub-kingdom of the Vermes : Class, Annelida (or Sea-worms).— 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 at- tributed to sexual selection. These animals are often beauti- fully colom-ed, 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 “ colom-ing with any other group in the invertebrate series;” yet * Dr. Morse lias lately discussed ‘ Proc. Boston Soc. of b'at. Hist.’ this subject in his paper on the vol. xiv., April, 1871. Adaptive Coloration of Mollusca, Chap. IX. Crustaceans. 265 Dr. McIntosh® cannot discover that these colotn-s are of any service. The sedentary annelids become duller-coloured, ac- cording to M. Quatrefages,'^ 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 appa.rently stand too low in the scale for the individuals of either sex to exert £iny choice in selecting a partner, or for the individuals of the same sex to struggle together in rivalry. Sub-kingdom 0/ the Aiihropoda: Class, Crustacea. — 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 summing-legs, antennm and sense-organs ; the females iDeing destitute of these organs, with them 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 con- sequently do not concern us. In various crustaceans, belonging to distinct families, the anterior antenn® are furnished with peculiar thi-ead-like bodies, which are believed to act as smelling-organs, and these are much more numerous in the males than in the females. As the males, without any unusual development of their olfactory organs, woidd almost certainly be able sooner or later to find the females, the increased number of the smelling- threads has probably been acquued thi’ough 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 gi’aduate into each other. In the one form the male is furnished with more numerous smelling-threads, 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 smelhng-threads, 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 ® See his beautiful monograph on ' See M. Perrier, M’Origine de ‘British Annelids,* part i, 1873, l*Homme d*npres Darwin,* ‘ Kevtie Scieutifique,’ Feb. 1873, p. 866. 266 The Descent of Man. Part II. were best able to hold her, have left the greatest number of progeny to inherit their respective advantages.® 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.® It serves, as I hear from Sir J. Lubbock, to hold the female, and for this same purpose one of the two posterior legs (d) on the same side of the body is converted into a forceps. In another family the inferior or posterior antennm are “curiously zigzagged” in the males alone. In the higher crustaceans the an- terior 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. 0. Spence Bate, is five times as great as that of the fe- male. In many species the chelae are of unequal size on the opposite side of the body, the right-hand 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 Fig. 4. Labidocera Darninii (from Lubbock). o. Part of right anterior an- tenna of male, forming a prehensile organ. h. Posterior pair of thoracic legs of male. c. Ditto of lemale. ® ‘ 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 ‘ Nature,’ 1870, p. 455) in a Norwegian crustacean, the Pontoporeut affink. “ Sec Sir J. Lubbock in ‘ Annals and Mag. of Nat. Hist.’ vol. xi. 1853, pi. i. and x. ; and vol. xii. (1853) pi. wi. See also Lubbock in ‘ Transact. Ent. Soc.’ vol. iv. new series, 1856-1858, p. 8. With re- spect to the zig-zagged antenwc mentioned below, see Fritz Miiller. ‘ Facts and Arguments for Darwin,’ 1869, p. 40, foot-note. Chap. IX. Crustaceans. 267 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 Fig. 5. Anterior part of body of Callianassa (from Milne-Edwards), showing the un- equal and differently-constructed right and left-hand cheliE of the male. N.B — ^The artist by mistake has reversed the drawing, and made the left-hand chela the largest. Fig. 6. Fig. 7. Fig. 6. Second leg of male Orchestia Tucuratinga (from Fritz MUller). Fig. 7. Ditto of female. often much larger in the male than in the female, is not known. As 1 hear from Mr. Bate, the chelae are sometimes of such length and size that they cannot possibly be used for caiTying food to the mouth. In the males of certain fresh-water prawns (Palaemon) the right leg is actually longer than the whole body.'“ The ^eat size of the one leg with its chelae may aid the male iu lighting with his rivals; but this will not account for their “ See a paper by Mr. C. Spence 585. I am greatly indebted to Mr. Bate, with figures, in ‘ Proc. Zoolog. Spence Bate for nearly all the above Soc.’ 1868, p. 36.3 ; and on the statements with respect to the chelaj nomenclature of the genus, ibid. p. of the higher crustaceans. 268 The Descent of Man. Part II. inequality in the female on the opposite sides of of the body. In Gelasimus, according to a statement quoted by Milnc-Ed^vards/* 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 chelm, which is enormously develoi^cd ; so that here it indirectly serves as a means of defence. Theii’ main use, however, is probably to seize and to secure the female, and this in some instances, as with Gammarus, is kno^vn to be the case. The male of the hermit or soldier crab {Vagurus) for weeks together, carries about the shell inhabited by the female.’^ The sexes, however, of the common shore-crab (Carcinus manas), 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 sti'oug pincei-s of the male ; but as she is aiught and carried about by the male before moulting, she could then be seized with impunity. Fi-itz Muller states that certain species of Melita are distin- guished from all other amphipods by the females having “ the “ coxal lamellm of the penultimate pair of feet produced iuto “ hook-hke processes, of which the males lay hold with the “ hands of the first pair.” The development of these hook-like processes has probably followed from those females which were the most securely held dui'ing the act of reproduction, having left the largest number of offspring. Another Brazilian amphi- jjod (Orchestia Danvinii, fig. 8) presents a case of dimorpliism, like that of Tanais ; for there are two male forms, which differ in the structure of their chelae.*® 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 special, but nearly equal advantages, from their differently shaped organs. 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 gi-eater 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 Ento- mostraca must be excepted. The chelae of many crustaceans are ‘ Hist. Nat. des Crust.’ tom. ii. of S. Devon.’ 1837, p. 50. Fritz Miiller, ‘Facts and Argu- Mr. C. Spence Bate, ‘ Brit, ments for Darwin,’ 1869, pp. 25-28 Assoc., Fourth Report on the Fauna Chap. IX. Crustaceans. 269 •weapons ■well adapted for fighting. Thus -when a De-vil-crab (Portumis picber) was seen by a son of Mr. Bate fighting with a Carcinus mcenas, the latter was soon thrown on its back, and had every limb tom from its body. When several males of a Brazilian Gelasimns, a species furnished -with immense pincers, were placed together in a glass vessel by Fi-itz Muller, they mutilated and killed one another. Mr. Bate put a large male Carcinus Fig. 8. Orchcstia Darwluil (from Fritz MUlIcr), showing the dUTerently-construoted cbckti of the two male forms. rtKcnas into a pan of water, inhabited by a femalo wliich was paired with a smaller malo; but tho latter was soon dispossessed. 270 Tlie Descent of Man. Part II. Mr. Bate adds, “ if they fought, the victory was a bloodless one, “ for I saw no wounds,” This same naturahst separated a male sand-skipper (so common on our sea-shores), 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 swdmming 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 males and females recognise each other, and are mutually attached. The mental powers of the Crustacea are probably higher than at first sight appears iDrobable. Any one w'ho tries to catch one of the shore-crabs, so common on tropical coasts, will perceive how wary and alert they are. There is a large crab (Birgits latro), found on coral islands, which makes a thick bed of the picked fibres of the cocoa-nut, at the bottom of a deei^ 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 eye-like 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 yormg animal as by an old one. The following case, however, can hardly be so con- sidered : a trustworthy natui-alist, Mr. Gardner,^* whilst watching a shore-crab (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 the distance of a foot ; it then saw the three other shells lying near, and evidently thinking that they might hkewise 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 well-marked case of difference of colour in the two sexes of om’ 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, bi;t 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 ’■* ‘ Travels in the Interior of 463, .an account of the habits of the Brazil,’ 1846, p. 111. I have given, Birgus. in my ‘ Journal of Researches,’ p. Chap. IX. Cr?(staceans. 271 tried to distinguisli by colour the sexes of the several species which inhabit the Mauritius, but failed, except with one species of SqniUa, probably S. stylifera, the male of which is described as being “ of a beautiful bluish-green,” with some of the appendages chcrry-red, whilst the female is clouded with brown and grey, “ with the red about her much less vivid than in the male.” 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 ceU-hke bodies, which exhibit beautiful changing colours ; these are absent in the females, and in both sexes of one species.^** 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 greyish-brown. 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 minutes — the 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 ornamented in order to attract or excite the female. 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 sub-kingdom of the Vertebrata; and in all cases it is eminently distinctive of characters which have been acquired through sexual selection. Fritz Muller gives some striking instances of this law ; thus the male sand-hopper (Orchestia) does not, until nearly full grown, acquire his large claspers, Mr. Ch. Fraser, ia ‘Proc. Zoo- Claus, ‘Die freilebenden Cope- log. Soc.’ 1869, p. 3. I am indebted poden,’ 1863, s. 35. to Mr. Bate for Dr. Po weir’s state- ” ‘ Facts and Arguments,’ &c- went. p. 79. 272 Paut II. The Descent of Man. which are very differently constructed from those of the female ; whilst young, his claspers resemble those of the female. Class, Arachnida (Spiders). — 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.*** In some species, however, the difterence 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 ** remai'ks that in certain genera the males can be specifically dis- tinguished 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 bright-coloured Sparassus at first re- sembles 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 ho 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 well-marked 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 variabihty 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 di-aws the same conclusion from ‘ A History of the Spiders of ‘ Ciw.itteri sessuali sccondarii dcgli Great Britain,’ 1861-64. For the Arachnidi,’ in the ‘Atti della Soc. following facts, soe pp. 77, 88, 102. Vcneto-Trentina di Sc. Nat. Padov.a,’ This author has recently pub- vol. i. F.asc. S, 1873. lished a valuable essay on the Chap. IX. Spiders. 273 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 dimorphic crustaceans. The male is generally much smaller than the female, sometimes to an extraordinary degree,-” 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 objeet of “ his attentions, enveloped by her in a web and then devoured, a “ sight which, as he adds, filled him with horror and indignation.” The Eev. 0. P. Cambridge accounts in the following manner for the extreme smallness of the male in the genus Xephila. “ M. Yinson 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 small for her to catch without great difficulty.” Westring has made the interesting discovery that the males of several species of Theridion^ have the power of making a stridulating sound, whilst the females are mute. The ap- paratus 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 well-known arachnologist Walckenaer, have declared that spiders are attracted by music.^^ Fi’om the analogy of the Orthoptera and Homoptera, Vinson Arandides des lies de la Reunion,’ pi. vi. figs. 1 and 2) gives a good instance of the small size of the male, in Epoira nigra. In this species, as I may add, the male is testaceous and the female black with legs banded with red. Other even moi’e striking cases of inec[uality in size between the sexes have been recorded (‘Quarterly Journal of Science,’ 1868, July, p. 429); but I have not seen the original accounts. Kirby and Spence, ‘Introduc- tion to Entomology,’ vol. i. 1818, p. 280. ‘Proc. Zoolog. Soc.’ 1871, p. 621. Theridion (Asagena, Sund.) serratipes, 4-punotatum ct gutta- tuin ; see Westring, in Kroyer, ‘ Naturhist. Tidskrift,’ vol. iv. 1842- 1843, p. 349; and vol. ii. 1846— 1849, p. 342. See, also, for other species, ‘Aranea: Suecica;,’ p, 184. Dr. II. H. van Zouteveen, in his Dutch translation of this work (vol. i. p. 444), has collected several cases. T 274 TJce Desce7it of Man. Paet II. 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.^ Class, Myriapoda. — In neither of the two orders in this class, the millipedes and centipedes, can I find any well-marked instances of such sexual differences as more particularly concern us. In Glomeris linibata, 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 pre- hensile hooks which serve to secmn the female. In some species of lulus the tarsi of the male are furnished with membranous suckers for the same pui-pose. 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.“ CIIAPTEE X. Secondaet Sexual Chaeactees of Insects. Diversified structures possessed by the males for seizing the females — Difl'erences between the sexes, of which the meaning is not understood — Difference in size between the sexes — Thysanura — Diptera — Hemiptera — Homoptera, musical powers possessed by the males alone — Orthoptera, musical instruments of the males, much diversified in structure ; pugnacity ; colours — Neuroptera, sexual differences in colour — Hyme- noptera, pugnacity and colours — Coleoptera, colours; furnished with great horns, apparently as an ornament ; battles ; stridulating organs generally common to both sexes. In the immense class of insects the sexes sometimes differ in their locomotive-organs, and often in their sense-organs, as in the pectinated and beautifully plumose antennte 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.' The ocelli are absent in the females of certain insects, as in the ** Hilgendorf, however, has lately called attention to an analogous structure in some of the higher crustaceans, which seems adapted to produce sound ; see ‘ Zoological Record,’ 18G9, p. G03. Walckenaer et P. Gervais, ‘ Hist. Nat. des Insectes : Apteres,’ tom. iv. 1847, pp. 17, 19, G8. ‘ Sir J. Lubbock, ‘ Tr.nusact. Linneau Soc.’ vol. xxv. 1866, p. 484. With respect to the Mu- tilllda: see Westwood, ‘ Jlodern Class, of Insects,’ vol. ii. p. 213. Chap. X. Insects. 275 Mutillidffl; 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,* “it is astonishing,” as Mr. B. D. Walsh* has remarked, “ how many different organs are worked in by natui'e “ for the seemingly insignificant object of enabling the male to “ grasp the female firmly.” The mandibles or jaws are some- times used for this purpose ; thus the male Corydalis cornutus (a neuropterous insect in some degree allied to the Dragon-flies, &c.) 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.'* One of the stag-beetles of North America (Lucanus elaphus) uses his jaws, which are much larger than those of the female, for the same purpose, but probably hke'wise for fighting. Di one of the sand-wasps (AmnwpJiila) 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, seiziag “ their partners round the neck with their sickle-shaped jaws ;” ® whilst the females use these organs for burrowing in sand-banks and making then: nests. The tarsi of the front-legs are dilated in many male beetles, or are furnished -with broad cushions of hams ; and in many genera of water-beetles they are armed with a round flat sucker, so that the male may adhere to the slippery body of the female. It is a * These organs in the male often differ in closely-allied species, and •afford excellent specific characters. But their importance, from a func- tional point of -view, as Mr. R. MacLachlan has remarked to me, has probably been overrated. It has been suggested, that slight dif- ferences in these organs would suffice to prevent the intercrossing of well-marked 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 in- instance, Bronn, ‘ Geschichte der Natur,’ B. ii. 1843, s. 1G4; and Westwood, ‘ Transact. Ent. Soc.’ vol. iii. 1842, p. 195) of distinct species having been observed in union. Mr. MacLachlan infoims me (vide ‘ Stett. Ent. Zeitung,’ 1867, s. 155) that when several species of Phryganidte, which pre- sent strongly-pronounced differences of this kind, were confined together by Dr. Aug. Meyer, thoy coupled, and one pair produced fertile ova. * ‘ The Practical Entomologist,’ Philadelphia, vol. ii. May, 1867, p. 88. * Mr. Walsh, ibid. p. 107. “ ‘ Modern classification of In- sects,’ 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. T 276 The Descent of Man. Part II. muclimore unusual circumstance that the female of some water- beetles (Dytiscus) haye their elytra deeply grooved, and in Acilius sulcatus thickly set with haii-s, as an aid to the male. The females of some other water- beetles (Hydroporus) have their elytra punctured for the same purpose.^ In the male of Crabro cribrarius (fig. 9), it is the tibia which is dilated into a broad horny jDlate, with minute mem- braneous dots, giving to it a sin- gular appearance like that of a riddle.'’^ In the male of Penthe (a genus of beetles) a few of the middle joints of the antennse are dilated and fmnished on the in- ferior surface with cushions of ham, exactly like those on the tarsi of the Carabidse, “ and obviously for “ the same end.” In male dragon- flies, “the appendages at the tip “ of the tail are modified in an “ almost infinite variety of curious “ patterns to enable them to em- “ brace the neck of the female.” Lastly, in the males of many in- sects, 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 j)an, or all thi'eo pairs are elongated, sometimes to an extravagant length.® 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 the left mandible much enlarged; so that the mouth is greatly distorted. In another Carabiduus beetle, Emygnathus,® we have the case, ® We have here a curious and inexplicable case of dimorphism, for Fig. 9. Crabro cribrarius. Upper figure, male ; lower figure, female. some of the females of four Euro- pean species of Dytiscus, and of certain species of Hydroporus, have their elytra smooth ; and no intei*- mediate gradations between the sulcated or punctured, and the quite smooth elytra have been observed. See Dr. H. Schaum, as quoted in the ‘ Zoologist,’ vol. v.-vi. 1847—48, p. 1896. Also Ivirby and Spence, ‘ Introduction to Entomology,’ vol. iii. 1826, p. 305. ’’ Westwood, ‘Modern Class.’ vol. ii. p. 193. The following state- ment about Penthe, and others in inverted commas, are taken from Mr. Walsh, ‘ Practical Entomolo- gist,’ Philadelphia, vol. ii. p- 88. ® Kirby ^and Spence, ‘ Introduct. &c., vol. iii. pp. 332-336. “ ‘ Insecta Maderensia,’ 1854, p. 20. Chap. X. Insects. i?y imique 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 c one of the most extra- ordinary is that certain male butterflies have their fore-legs more or less atrophied, with the tibiae and tarsi reduced to mere ru- dimentary knobs. The wings, also, in the two •sexes often differ in neru-ation,“ and some- times considerably in outline, as in the Ari- coris 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, aaid horny excrescences on the discs of the posterior pair.'^ In several British butter- flies, as shewn by klr. Wonfor, the males alone are in parts clothed with peculiar scales. The use of the bright light of the female glow-worm has been subject to much discus- sion. The male is feebly luminous, as are the larvfs and even the eggs. It has been sup- posed by some authors that the light serves to frighten away enemies, and by others to guide the male to the female. At last, l\Ir, Belt appears to have solved the difficulty : he finds that all the Lampyridee which he has tided 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 Lampyridre •closely, in order to be mistaken for them, and thus to escape destruction. He further be- lieves that the luminous sj)ecies profit by being at once recognised as unpalatable. It is probable that the same explanation may be extended to the E. Doubleday, ‘ Annals and Hag. of Nat. Hist.’ vol. i. ] 848, g. 10. Taphroderes distortus (much en- larged). Upper fig- ure, male ; lower figure, female. 379. I may add that the ■wings in certain Hymenoptera (see Shuckard, ‘ Fossorial Hymenop.’ 1837, pp. 39- 43) differ in neuration according to sex. '* H. W. Bates, in ‘Journal of Proc. Linn. £Joc.’ vol. vi. 1862, p. 74. Mr. Wonfor’s observations are quoted in ‘ Popular Science Review,’ 1868, p. 343. ‘ The Naturalist in Nicaragua,’ 1874, pp. 316-320. On the phos- phoi-escence of the eggs, see ‘Annals and Mag. of Nat. Hist.’ 1871,’ Nov., p. 372. 2/8 The Descent of Man. Part II. Elaters, both sexes of which are highly luminous. It is not known why the wings of the female glow-worm 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 the male ; and why the larvae themselves are likewise luminous. Difference in Size between the Sexes. — ^^’'ith insects of all kinds the males are commonly smaller than the females; and tln'H difference can often be detected even in the larval state. So considerable is the difference between the male and female cocoons of the silk-moth (^Bombyx mori), that in ikance they are separated by a particular mode of weighing.^ 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 develop- ment of the caterpillars of Bombyx cynthia and yamainai, and especially to that of some dwarfed caterpillars reared from a second brood on unnatural food, “ that in proportion as the in- “ dividual moth is finer, so is the time required for its metamor- “phosis longer; and for this reason the female, which is the “ larger and heavier insect, from having to caiTy her numerous “ eggs, will be preceded by the male, which is smaller and has “ less to mature.” Now as most insects are short-lived, and as they are exposed to many dangers, it would manifestly be ad- vantageous to the female to be impregnated as soon as possible. This end would be gained by the males being fii’st matured in large numbers ready for the advent of the females ; and this again would naturally follow, as Mr. A. E. Wallace has re- marked,^® through natural selection; for the smaller males would be first matured, and thus would procreate a large number of oflspring which would inherit the reduced size of them male parents, whilst the larger males from being matured later would leave fewer offspring. There are, however, exceptions to the rule of male insects being smaUer than the females : and some of these exceptions aro intelligible. Size and strength would bo an advantage to the males, which fight for the possession of tho females; and in those cases, as ■with the stag-beetle (Lucanus), the males are larger than the females. There are, however, other beetles Robinet, ‘Vers i Sole,’ 1848, rol. v. p. 486. p. 207. ‘ Journal of Proc. Ent. Sco. ** ‘Transact. Ent. Soc.’ 3rd series, Feb. 4th, 1867, p. Ixii. Chap. X. TJiysanura. 279 ■which are not known to fight together, of which the males exceed the females in size ; and the meaning of this fact is not kno'wn ; 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 short-lived, and there would be ample time for the pairing of the sexes. So again, male dragon-flies (Libellulidse) are sometimes sensibly larger, and never smaller, than the females;^® 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 easily-overlooked 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 Ayis onellifica, AntMdium manicatum, and Anthopliora 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 ah’. Increased size has here been acquired in op- position to the usual relation between size and the period of development, for the males, though larger, emerge before the smaller females. We will now review the several Orders, selecting such facts as more particularly concern us. The Lepidoptera (Butterflies and Moths) will be retained for a separate chapter. Order, Thjsanura. — The members of this lowly organizeees express certain emotions, as of anger, by the tone of their humming; and according to H. MiiUer (p. 80), the males of some species make a peculiar singing noise whilst pursuing the females. M. Perrier in his article ‘ la Se- lection sexuelle d’apr6sDarwin’(‘Re- rue 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 fa- cilitating 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 bo l)retended 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 grand- father? The acquirement of new characters by the sterile worker-bees is a much more difficult case, but I have endeavoured to show in my ‘ Origin of Species,’ how these sterile beings are subjected to the power of natural selection. Quoted by Westwood, ‘ Modern Class, of Insects,’ vol. ii. p. 214-. 294 The Descent of Man. Pakt II. Order, Coleoptera (Beetles). — 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 diamond-beetles, 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 flower-feeding species ; but they may serve as a warning or means of recognition, on the same principle as the phosphorescence of the glow-woim. As TOth 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 may 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 weU-marked secondary sexual characters. Blind beetles, which cannot of coui’se behold each other’s beauty, never, as I hear from Mr. Waterhouse, jun., exhibit bright colours, though they often have polished coats ; but the expla- nation of their obscurity may be that they generally inhabit caves and other obscure stations. Some Longicorns, especially certain Priouidse, offer an excep- tion to the rule that the sexes of beetles do not differ in colom-. Most of these insects are large and splendidly coloui'ed. The males in the genus Pyrodes,®^ which I saw in Mr. Bates’s col- lection, are generally redder but rather duller than the females, the latter being colomud of a more or less splendid golden-green. On the other hand, in one species the male is golden-green, the female being richly tinted with red and pm-ple. 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 Prionidas, in Pyrodes jMlcherrimus, in which the sexes differ conspicuously, tins 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 (‘In- troduct. to Entomology,’ vol. iii. p. 301) mention a Cantharis, Meloe, Khagium, and the Leptura testacea ; the male of the latter being tes- taceous, with a black thorax, and the female of a dull red all ovei. 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 obsciu’ely 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 0. ruficollis) having a • ufous thorax. Chap. X. Coleoptera. 295 which the sexes differ, are coloured more richly than the males, and this does not accord with the common rule in regard to colour, when acquired through sexual selection. 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, &c., 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 re- markable forms. (Pigs. 16 to 20.) The females generally ex- hibit 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 of Plianoeus 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 have two. VIg. 16. Chaicosomo atlas. Upper figure, tnalo (reduced); lower figure, female (nat. size). 2 he Descent of Man. Part II, 296 *• ^ A* Fig. 1';. Copi is isidis. (Left-hand figures, males.) Fig. 18. I’hanajus faunus. Lipelicus canton. Fig. 20. Onthophagus rnngifcr, enlarged. Chap. X, Coleoptera. 297 In almost all cases, the horns are remarkable from their ex- cessive 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®* found that in Phanceus carnifex the horns were thrice as long in some males as in others. Mr. Bates, after exaniining above a hundred males of OnthopTiagus 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 closely-allied 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 show marks of friction, as if used for any ordinary work. Some authors sup- pose®® 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 sufBcient 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 Copridm, did not find any marked difference in this respect amongst well-developed individuals. In Lethrus, moreover, a beetle belonging to the same great division of the Lamelhcorns, the males are known to fight, but are not provided with horns, though their mandibles are much larger than those of the female. 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 closely-aUied 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 apparently for this sole pm’pose. The males of Onitis furcifer (fig. 21), and of some other ‘ Proc. Entomolog. Soo. of Philadelphia,’ 1864, p. 228. 1^11 auu llj Entomolog.’ vol. iii. p. 300. Kirby and Spence, ‘ Introduct, Paet II. 29^ The Descent of Man. 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 chnging to the female. Although the males have not even a trace of a horn on the upper surface of the body, yet the fe- males plainly exhibit a rudiment of a single horn on the head (fig. 22, a), and of a crest (&) on the thorax. That the shght thoracic crest in the female is a rudiment of a pro- jection 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 hardJy be a doubt that the little point (a) on the head of the female Onitis Fig. 22. Left-band figure, male of Onitis furcifer, viewed laterally. Right-hand figure, female, a. Rudiment of cephalic horn. 6. Trace of thoracic horn or crest. furcifer, as well as on the head of the females of two or three allied species, is a rudimentarj’- representative of the cephalic horn, wliich is common to the males of so many Lamellicom beetles, as in Phanseus (fig. 18). 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. VVe 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, wo 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 the females would not have been thus obliterated. Fig 21. Onitis furcifer, male viewed from be- neath. Chap. X. Coleoptera. 299 The cases hitherto given refer to the Lamellicorns, hut the males of some few other beetles, belonging to two widely distinct gi-oups, namely, the Cnrcnlionidm and Staphylinidse, are fur- nished with horns — in the former on the lower surface of the body,®® in the latter on the upper surface of the head and thorax. In the Staphylinidm, 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 apd in the development of their horns, without intermediate gradations. In a species of Bledius (fig. 23), also belonging to the Staphylinidse, Professor Westwood Fig. 23. Bledius taurus, magnified. Left-hand figure, male ; right-hand^figure female. 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.”®^ Here we apparently have a case of compensation, which throws light on that just given of the supposed loss of the upper horns by the males of Onitis. Law of Battle. — Some male beetles, which seem ill-fitted for fighting, nevertheless engage in conflicts for the possession of the females. Mr. Wallace®® 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 stag-beetle (_].ucanus cervun), 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 Kirby and Spence, ‘ Introduct. gonium in an intermediate condi- Entomolog.’ vol. iii. p. 329. ‘ Modern Classification of In- sects,’ vol. i. p. 172 ; Siagonium, p. 172. In the British Museum I noticed one male specimen of Sia- tion, so that the dimorphism is not strict. ‘The Malay Archipelago,’ vol. ii. 1869, p. 276. Riley, Si.xth ‘ .Report on insects of Missouri,’ 1874, p. 115. 300 Paet IL The Descent of Man. engage in fierce conflicts. When Mr. A. H. Davis®* 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 Lucanidse, as well as of the above-mentioned Leptorhynchus, are larger and more powerful insects than the females. The two sexes of Leihrvs cephaiotes (one of the Lamellicorns) inhabit the same burrow; and the male has larger mandibles than the female. If, during the breeding-season, 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 con- tinually pushing him on from behind ; and the battle lasts until the aggressor is killed or runs away.™ The two sexes of another Lamellicorn beetle, the Ateuchus cicatricosus, live in pairs, and seem much attached to each other ; the male excites the female 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. 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 LameUicorns and Staphyhnidse. A perfect series can be formed from the best-provided to the worst-provided or degenerate males. Al- though the mandibles of the common stag-beetle, and probably of many other species, are used as efiBcient 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 con- spicuous 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 Chiasognathiis Grant ii of S. Chile — a splendid beetle belonging to the same family — has ““ ‘Entomological Magazine,’ vol. Quoted from Fischer, in ‘Diet, i. 1833, p. 82. See also on the Class, d’llist. Nat.’ tom. x. p. 324. conflicts of this species, Kirby and ” ‘ Ann. Soc. Entoraolog. France,’ .Spence, ibid. vol. iii. p. 314; and 1866, as quoted in ‘ .Journal of Westwood, ibid. vol. i. p. 187. Travel,’ by A. Murray, 1868, p. 135. Chap. X. Coleoptera. 301 enormously developed mandibles (fig. 24) ; he is bold and pug- nacious ; when threatened he faces round, opens his great jaws, and at the same time stridulates loudly. But the mandibles were not strong enough to pinch my finger so as to cause actual pain. 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 hve in pairs and show mutual affection ; many have the power of stridulating when excited ; many are furnished with the most ex- traordinary horns, apparently for the sake of ornament; and some, which are diurnal in their habits, are gor- geously coloured. Lastly, several of the largest beetles in the world belong to this family, which was placed by Linnaeus and Fabricius at the head of the Order.'^^ Stridulating organs. — Beetles belong- ing to many and widely distinct families possess these organs. The soimd thus produced can sometimes be heard at the distance of several feet or even yards,'^^ but it is not comparable with that made by the Orthoptera. The rasp generally consists of a narrow, shghtly-raised 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 Typhmus, minute, bristly or scale-like prominences, with which the whole surrounding surface is covered in* approximately ]3arallel lines, could be traced passing into the ribs of the rasp. The Westwood, ‘Modern Class.’ Curculionidoe,’ ‘ Annals and Mag. ol V'n . o Nat. Hist.’ vol. vi. I860, p. 14. ^ Wollaston, ‘ On certain Musical Fift. 24. Cliiasognathus grantil, reduced. Upper figure, male; lower figure, female. 302 The Descent of Man. Part IL 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 conversely the rasp across the scraper. Fig. 25. Necrophorus (from Landois). r. The two rasps. Left-hand figure, part of the rasp highly magnified. These organs are situated in -widely different positions. In the carrion-beetles (Necrophorus) t-wo parallel rasps (r, fig. 25) stand on the dorsal surface of the fiLfth abdominal segment, each rasp'-* 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 Crioceridfe, and in Cli/thra 4^punctata (one of the Chrysomehdfe), and in some Tenebrionidfe, &c.,'^® the rasp is seated on the dorsal apex of the abdomen, on the pygidium or pro-pygidium, 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.'^® In certain Curculionidfe and Carabidfe,” the parts Landois, ‘ Zeitschrift fiir wiss. Zoolog.’ B. xvii. 1867, s. 127. 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 informa- tion 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 ‘Entomolo- gist’s Monthly Magazine,’ vol. vi. p. 130. Schiodte, translated in ‘ Annals and Mag. of Nat. Hist.’ vol. xs. 1867, p. 37. ’’’’ Westringhas described (Kroyer, ‘ Naturhist. Tidskrift,’ B. ii. 1848- 49, p. 334) the stridulating organs in these two. as well ns in other families. In the Carabida; I have examined Elaphrus uliginosus and lilethisa multipxmctata, sent to me by Mr. Crotch. In Blethisa the transverse ridges on the furrowed border of the abdominal segment do Chap. X. Coleoptera. 303 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 Pelubius Hermanni (one of Dytiscidm or water-beetles) 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 irroduced by the extreme horny margin of the abdomen being scraped against the rasps. In a great number of long-horned beetles (Longi- cornia) the organs are situated quite otherwise, the rasp being on the meso-thorax, which is rubbed against the pro-thorax; Landois counted 238 very fine ribs on the rasp of Oeramlyx heros. Many Lamelhcorns 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 sabuhsits, 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 Typhceus a narrow ridge runs obliquely across (r, fig. 26) the coxa of each hind-leg (having in G. ster- corarius 84 ribs), which is scraped by a specially projecting part of one of the ab- dominal segments. In the nearly allied Copris lunaris, an excessively narrow fine rasp runs along the sutural margin of the elytra, with another short ra.sp near the basal outer mar- gin; but in some other Coprini the rasp is seated, according to Leconte,'^® on the dorsal surface of the abdomen. In Oryctes it is seated on the'pro-pygidium ; and, according to ^ the same entomologist, in some other Dynastini, j,j nind-ie of on the under surface of the elytra. Lastly, Geotrupes stercora- Westring states that in OmalopUa brunnea the rms (from Landois). rasp is placed on the pro-sternum, and the Femur. scraper on the meta-sternum, the parts thus occupying the under surface of the body, instead of the upper surface as in the Longicorns. We thus see that in the different coleopterous families the not, as far as I could judge, come into play in scraping the rasps on the elytra. ” I am indebted to Mr. Walsh, of Illinois, for having sent me e.x- tracts from Leconte’s ‘Introduction to Entomology,’ pp. 101, 143, 304 T}ie Descent of Man. Pakt II Btridulating 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 intelhgible, 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 stridulatuig organs. Some beetles as they move, now produce, either intentionally or unintentionally, a shuffling noise, without possessing any proper organs for the purpose. Mi\ Wallace informs me that the Euchirus lonyimanus (a Lamelhcorn, -with the anterior legs wonderfully elongated in the male) “ makes, whilst moving, a low hissing sound by the pro- “ trusion and contraction of the abdomen ; and when seized it “ produces a grating sound by rubbing its hind-legs against the “ edges of the elytra.” The hissiug sound is clearly due to a narrow rasp running along the sutural margin of each elytron ; and I could likewise make the grating sotmd by rubbing the shagreened surface of the femur against the gi-anulated margin of the corresponding elytron ; but I could not here detect any proper rasp ; nor is it hkely that I could have overlooked it iu so large an insect. After examining Cychrus, and reading what Westrmg has written about this beetle, it seems very doubtful •n*hether it possesses any true rasp, though it has the power of emitting a sound. From the analogy of the Orthoptera and Homoptera, T expected to find the stridulating organs in the Coleoptera differing according to sex; but Landois, who has carefully examined several sioecies, observed no such difference ; nor did Westring; nor did Mr. G. E. Crotch in preparing the many specimens wliich he had the kindness to send me. Any difference in these organs, if shght, would, however, be difficult to detect, on account of their great variability. Thus, in the fir-st pau of specimens of Necrophorus humator and of Pelohius which I ex- amined, the rasp was considerably larger in the male than in the female; but not so -with succeeding specimens. In Geo- triipes 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 fifty-seven h'Ting 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 Chap. X. Coleoptera. 305 to tliG females in both the lots. Mr. F. Smith has kept alive numerous specimens of Mmoynchus pseudacori (Gurculionidse), and is convinced that both sexes stridulate, and apparently in an eqiial degree. 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 E. gibhus, 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 Jf. crihratostriatus 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 this latter structure. Again, in three species of the Lamellicorn genus Oi*yctes, we have a nearly parallel case. In the females of 0. gryphus and nasicomis the ribs on the rasp of the pro-pygidium 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 0. 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 three- fourths 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 pushed backwards and forwards. In the case of the Heliopathes and Oryctes there can hardly l)e a doubt that the males stridulate in order to call or to excite the females; but with most beetles the stridulation X The Descent of Man. Paiit II, 306 apparently serves both sexes as a mutual call. Beetles stridu- late under various emotions, in tho 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 hollovr stems of trees in the Canary Islands, Messrs. WoUaston 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.’® 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 stridu- lation serves as a sexual call is supported by the fact that death- ticks {AnoMum tessellatum) are well known to answer each other’s ticking, and, as I have myself observed, a tapping noise artificially made. Mr. Loubleday also informs me that he has sometimes observed a female ticking,®® 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 gradually developed by means of sexual selection into true stridulating organs. "® M. P. de la Brulerie, as quoted in ‘ Journal of Travel,’ A. Murray, vol. i. 1868, p. 135. •'® According to Mr. Doubleday, “ the noise is produced by ihe iu- “ sect raising itself on its legs as high as it can, and then striking “ its thorax five or six times, in “ rapid succession, against the sub- “ stance upon which it is sitting.” For references on this subject sete Landois, ‘ Zeitschrift fiir wissen. Zoolog.’ B. xvii. s. 131. Oliver says (as quoted by Kirby and Spence, ‘ Introduct.’ vol. ii. p. 395) that the female of Pimelia striata produces a rather loud sound by sticking her abdomen against any hard substance, “ and that the male, “ obedient to this call, soon attends “ her, and they pair.” Chap. XT, Butterflies and Moths. 307 CHAPTER XL Insects, continued. — Oedkr Lepidopteba. (butterflies and moths.) Courtship of butterflies — Battles — ^Ticking noise — Colours common to both sexes, or more brilliant in the males — Examples — Not due to the direct action of the conditions of life — Colours adapted for protection— Colours of moths — Display — Perceptive powers of the Lepidoptera — Variability — Causes of the dilference in colour between the males and females — Mimicry, female butterflies more brilliantly coloured than the males — Bright colours of caterpillars — Summary and concluding remarks on the secondary sexual characters of insects — Birds and insects compared. 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 pm-suing and crowdmg round the same female. Their courtship appears to be a prolonged affair, for I have frequently watched one or more males pirouet- ting 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 ground and closed her wings, so as to escape from his addi-esses. Although butterflies are weak and fragile creatm-es, they are pugnacious, and an Emperor butterfly ^ 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 by the greatest “ ferocity.” The Ageronia feronia makes a noise like that produced by a toothed wheel passing under a spring catch, and which can bo 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.'^ ’ Apatura Iris: ‘The Entomolo- Naturalist,’ 1868, p. 183. gist’s Weekly Intelligence,’ 1859, p. * See my ‘Journal of Researches, 139. For the Borne.an Butterflies, 1845, p. 33. Mr. Doubleday has Bce C. Collingwood, ‘ Rambles of a detected (‘ Proc. Ent. Soc.’ March X 2 308 The Descent of Man. Part II. Some moths aJso produce sounds ; for instance, the males of Thecophora fovea. On two occasions Mr. F. Buchanan White » heard a sharp quick noise made by the male of Bylophila 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 sound-producing organs in the Lepidoptera appear to stand in some relation with the sexual functions. I have not alluded to the well-known noise made by the Death’s Head Sphinx, for it is generally heard soon after the moth has emerged from its cocoon. Girard has always observed that the musky odour, which is emitted by two species of Sphinx moths, is peculiar to the males and in the higher classes we shall meet with many instances of the males alone being odoriferous. 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 Ihe 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 at- tractive 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 to answer these questions a body of facts must be given. 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, orange-tip, &c. {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 3rd, 1845, p. 123) a peculiar mem- branous sac at the base of the front wings, which is probably con- nected with the production of the sound. For the case of Thecophora, see ‘ Zoological Kecord,’ 1869, p. 401. For Mr. Buchanan White’s observations, ‘ The Scottish Natural- ist,’ July 1872, p. 214. ^ ‘ The Scottish Naturalist,’ Julv 1872, p. 213. ■* ‘ Zoological Record,’ 1869, p. 347. Chap. XL Butterfiies aitd Moths. 309 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 Epicaha, 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.® 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 hke 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 parent-form of the genus. The sexes in these three cases have thus been rendered nearly ahke, though in an opposite manner. In the allied genus Eubagis, both sexes of some of the species are plain-coloured and nearly alike ; whilst with the greater number the males are decorated with beautiful metalhc 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 than they resemble their own males. In the genus Papiho, all the species of the .Tineas 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 * See also Mr. Bates’s paper in the same subject, in regard tc ‘ Proc. Ent. Soc. of Philadelphia,’ Diadema, in ‘ Transact. Entomoloe 1865, p. 206. Also Mr. Wallace on Soc. of Loudon,’ 1868, p. 278. The Descent of Man. Past II. o lO others the males are either a little brighter, or very much more superb than the females. Tlio genus Junonia, allied to our Vanessse, offers a nearly parallel case, for although the sexes of most of the species resemble each other, and arc destitute of rich colours, yet in certain species, as in J. cenone, the male is rather more bright-coloured than the female, and in a few (for instance J. andremiaja) the male is so different from the female that he might be mistaken for an entirely distinct species. Another striking case was pointed out to me in the British Museum by Mr. A. Butler, namely, one of the tropical American Theclse, 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 Lycmna, illustrate the various dif- ferences in colour between the sexes, almost as well, though not in so striking a manner, as the above exotic genera. In Lycxna 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 male are of a fine blue, bordered with black ; whilst those of the female are brown, with a similar border, closely resembliag the wings of L. agestis. Lastly, in L. anon 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 show, in the first place, that when the sexes of butterflies differ, the male as a general rule is the more beautiful, and departs more firom the usual typo of coloui-ing of the gi-oup 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 ])erhaps recovered, the primordial colour’s of the group. It also deserves notice that in those gi’oups in which the sexes differ, the females usually somewhat resemble the males, so that when Chap. XI. Buttei-Jiies and MotJis. 311 the males are beautiful to an extraordinary degree, the females almost invariably exhibit some degree of beauty. I’rom the many cases of giudation 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 con- clude that the causes have generally been the same which have determined the brilliant colouring of the males alone of some species, and of both sexes of other species. 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 ® has shewn by the comparison of various closely-allied groups of insects from the temperate and tropical regions, that this view cannot he maintained ; and the evidence becomes conclusive when bril- liantly-coloimed males and plain-coloured 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 brilhant and beautifully-arranged colours are the purposeless result of the nature of the tissues and of the action of the snrrmmrling conditions. 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 then- escaping observation and danger. But butterflies would be particularly hable to be attacked by their enemies when at rest ; and most kinds whilst resting raise their wings vertically over them 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. Bossier, I believe, first noticed the similarity of the closed wings of certain Vanessas 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’ of a common Indian and Sumatran butterfly (Kalhma), 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 ^ ‘ The Xaturalist on the Ama- 1867, p. 10. A woodcut of the zons,' vol. i. 186;5, p. 19. Kallima is given by Mr. Wallace in ’ See the interesting article in ‘ Hardwicke’s Science Gossip,’ Sept, iho ‘ Westminster Review,’ July 1867, p. 196. . * The Descent of Man. Part II. !I2 surfaces of the wings are brilliantly coloured, and yet are protective ; thus in Theda 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 bo 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 serves as a protection.® Although the obscure tints both of the upjier 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 Vanessse, our white cabbage-butterflies (Pieris), or the great swallow-tail Papilio which haunts the open fens — for these butterflies are thus rendered visible to every Living creature. In these species both sexes are alike ; but in the common brim- stone butterfly ( Gonepteryx rhamni), the male is of an intense yellow, whilst the female is much paler; and in the orange- tip (^Anthocharis cardamines) the males alone have their wings tipped wdth 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,® that the female of one of the Lycaense 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 shews that the blue colour cannot be in any way protective. Nevertheless, it is probable that conspicuous colours are in- dii'ectly 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 orange- tip butterfly, above referred to, and of an American species (^Anth. genutui) probably shew us the primordial colours of the parent-species of the genus; for both sexes of four or five widely-distributed species are coloured in nearly the same manner. As in several previous cases, wo may here infer that it is the males of Anth. cardamines and genutia which have departed from the usual typo of the genus. In the Anth. eara “ Mr. G. Fniser, in ‘ Nature,’ " ‘ Einfluss der Isolining auf die April 1871, p. 489. Artbildung,’ 1872, p. 58. Chap. XI. Butterflies and Moths. 313 from California, tho orange-tips to the wings have been partially developed in the female ; bnt they are paler than in the male, and slightly different in some other respects. In an allied Indian form, the Iphias glaucippe, the orange-tips are fully developed in both sexes. In this IpMas, as pointed out to me by Mr. A. Butler, the tmder surface of the wings marvellously resembles a pale- coloured leaf ; and in our English orange-tip, the under surface resembles the flower-head of the wild parsley, on which tho butterfly often rests at night.^® 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 Blr. Wallace has remarked, for escaping detection. The front- wings of the Bombycidse and Noctuidm,” when at rest, generally overlap and conceal the hind-wings ; 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 hind-wings 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 Under-wings (Triphsena) often fly about during the day or early evening, and are then conspicuous from the colour of their hind-wings. 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 in- stance, Mr. Weir turned into his aviary a vigorous specimen of Triphcena pronuha, 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.*^ We are thus reminded of a statement made >“ See the interesting observations Science Gossip,’ Sept. 1867, p. 193. by Mr. T. W. Wood, ‘The Student,’ See also, on this subject, Mr. Sept. 1868, p. 81. Weir’s paper in ‘Transact. Ent. Soc.’ " Mr. Wallace in ‘ H.ardwicke’s 1869, p. 23. Paet II. 314 Descc7it of Man. by Mr. ‘Wallace,’" namely, that in the Brazilian forests and hlalayan islands, many common and highly-decorated butterflies are weak flyers, though furnished with a broad expanse of wing ; and they “ are often captured with pierced and broken M-ings, “ 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 increased expanse of the wings may have been in- “ directly beneficial.” Display. — 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 ZygEenidm, several Sphingidae, Uraniida!, 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 bright-coloured noctumal species have been recorded. 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 maimer. In some tropical species the lower surface is even more brilliantly coloured than the upper.’" In the Eng- bsh fritillaries {Argynnis) the lower surface alone is orna- mented 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 ” ‘ Westminster Review,’ July 2867, p. 16. For instance, Lithosia ; but Prof. Westwood (‘Modern Cliiss. of Insects,’ vol. ii. p. 390) seems sur- prised at this case. On the relative colours of diurnal and nocturnal Lepidoptora, see ibid. pp. 333 and 392 ; also Harris, ‘ Treatise on the Insects of New England,’ 1842, p. 315. “ Such diflerences 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 Papilionida: of the JIalayan Region,’ in ‘Transact. Linn. Soc.’ vol. ixv. part i. 1865. Chap. XI Butterjiies and Moths. useful chai-aoter 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 hind- wings are obscure, and are always covered by the front-wings when these butterflies are at rest; but the third species has black hind-wings, beautifully spotted with red and white, and these are fully expanded and displayed whenever the butterfly vests. Other such cases could be added. If we now turn to the enormous group of moths, which, as I hear from Mi’. Stainton, do not habitually expose the under surface of their wings to full view, we And 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 bo noticed, as the case of Hypopyra.^® Mr. Trimen informs me that in Guenee’s great work, three moths are figured, in which the under surface is much the more brflliant. For instance, in the Australian Gastrophora the upper surface of the fore-wing is pale greyish-ochreous, while the lower surface is magnificently ornamented by an ocellus of cobalt-blue, placed in the midst of a black mark, surrounded by orange-yeUow, and this by bluish-white. But the habits of these three moths are unknown ; so that no exjilanation can be given of their unusual style of colouring. Mr. Trimen also informs me that the lower surface of the wings in certain other Geometrm^'' and quadrifid Noctuse are either more variegated or more brightly-coloui-ed 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 con- “ siderable 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 Saturniidse 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^® observes that they resemble butterflies in some of their movements; “for “ instance, in the gentle waving up and down of the wings as il “ for display, which is more characteristic of diurnal than of “ nocturnal Lepidoptera.” See Mr. Wormald on this the Gcometra:) in ‘Transact. Ent. moth : ‘Proc. Ent. Soc.’ Mai'ch 2nd, Soc.’ new series, vol. v. pi. xv. and 1868. xvi. See also an account of the S. ‘8 ‘ Proc. Ent. Soc. of Loudon ’ American genus Erateina (one of July 6, 1868, p. xxvii. ’ 3i6 The Descent of Man. Part II. It is a singular fact that no British moths which are bril- liantly 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 lo, is described as having its fore-wings deep yellow, curiously marked with purplish-red spots ; whilst the wings of the female are purple-brown, marked with grey lines.'® 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,®® 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 hind-wings whiter than those of the female — of which fact Agrotis exclamationis offers a good instance. In the Ghost Moth (^Hepialus humuli) tJie difference is more strongly marked ; the males being white, and the females yellow with darker markings.®' It is probable that in thes^cases the males are thus rendered more conspicuous, and more easily seen by the females whilst flying about in the dusk. 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 brilhant Harris, ‘ Treatise,’ &c., edited by Flint, 1862, p. 395. *® For instance, I observe in my son’s cabinet that the males are darker than the females in the Lasiocampa quercus, Odonestis pota- toria, 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 ex- plained. The white female of the Cycnia resembles the very common Spilosoma mcnthrasti, both sexes of which are white ; and Mr. Stainton observed that this latter moth was rejected with utter disgust by a whole hiTfOd 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 de- ceptive colour would thus be highly beneficial. It is remarkable, that in the Shetland Islands the male of this moth, instead of differing widely from the female, frequently re- sembles her closely in colour (see Mr. MacLachlan, ‘ Transact. Ent. Soc.’ vol. ii. 1866, p. 459). Mr. G. Fraser suggests (‘Nature,’ April 1871, p. 489) that at the season of the year when the ghost-moth ap- pears in these northern isl0 With respect to this and the ‘ Ciutalogue of Acanth. Fishes following species I am indebted to in th^e British Museum,’ by Dr. Dr. Giinther for information : see Oilnther, 1861, pp. 138-151. .also his paper on the ‘Fishes of Central America,' in ‘Transact. 1867, p. 466. .Zoolog. Soc.’ vol. vi 1868, p. 485. 338 The Descent of Man. Paht II. with a row of large, round, ocellated, bright-coloured 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 Xipho- phorus nellerii (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.” In a siluroid fish, inhabiting the fresh waters of South America, the Plecostomus barbatus (fig. 31), the male has its mouth and inter-operculum 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 ten- tacles 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 Cliimoera monstrosa, the male has a hook- shaped 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.^® The structures as yet referred to are permanent in the male after he has arrived at maturity ; but with some Blennies, and in another alhed genus,^° a crest is developed on the head of the male only during the breeding-season, and the body at the same time becomes more brightly-coloured. 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 ” Dr. Gunther makes this re- Water,’ July 18G8, p. 377, with a mark; ‘Catalogue of Fishes in the figure. Many other cases could be British Museum,’ vol. iii. 1861, p. added of structures peculiar to the 141. male, of which the uses are not ** See Dr. GUnther on this genus, known, in ‘Proc. Zoolog. Soc.’ 1868, p. 232. =» Dr. GUnther, ‘ Catalogue of ” F. Buckland, in ‘ Land and Fishes,’ vol. iii. pp. 221 and 240. Chap. XII, Fishes. 339 340 The Desce7it of Ma^i. ?A.ET II. neither sex is thus provided. In many of the Chromidse, for instance in Geophagus and especially in Cichla, the males, as I hear from Professor Agassiz,^* have a conspicuous protuberance on the forehead, which is wholly wanting in the females and in the young males. Professor Agassiz adds, " 1 have often “ observed these fishes at the time of spawning when the pro- “ tuberance 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 caruncles 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 breeding-season. 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 sahnon at this season is “marked on the cheeks with “ orange-coloured 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 black- “ fish.” ^ An analogous and even greater change takes place with the Salmo eriox or bull trout; the males of the char (S. umhla) are likewise at this season rather brighter in colour than the females.^ The colours of the pike (Asox reticulatns) of the United States, especially of the male, become, during the breeding-season, exceedingly intense, briUiant, and nidescent.-* Another striking instance out of many is afforded by the male stickleback (^Oasterosteits hiurus), which is described by Mr. Warington,^® 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 gi'een “ feathers of some humming-birds. The throat and belly are “ of a bright crimson, the back of an ashy-green, and the whole “ fish appears as though it were somewhat translucent and See also ‘ A Journey in Brazil,’ Mag. of Nat. History,’ vol. vL 1841, by Prof, and Mrs. Agassiz, 1868, p. p. 440. Z20. ‘The American Agriculturist, Yarrell, ‘ British Fishes,’ vol. 1868, p. 100. ii. 1836, pp. 10, 12, 35. *’ ‘Annals and Mag. of Nat. Hist.’ ** W. Thompson, in ‘Annals and Get. 1852. Chap. XII. Fishes. 34^ “ 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 the glowing tints subside. With respect to the courtship of fishes, other cases have been observed since the first edition of this book appeared, besides that ah-eady given of the stickleback. Mr. W. S. Kent says that the male of the Ldbrus mixtus, which, as we have seen, differs in colour from the female, makes “ a deep hollow in the sand of the “ tank, and then endeavour's in the most persuasive manner to in- “ duce a female of the same species to share it with him, swim- “ ming backwards and forwards between her and the completed “ nest, and plainly exhibiting the greatest anxiety for her to foDow.” The males of Cantliarus lineatus become, during the breeding- season, 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 com- “ panions 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 with the greatest care.^“ 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.^'^ The males are most beautifully coloured, more so than the females. During the breeding-season they contend for the possession of the females; and, in the act of com'tship, 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 “ Tetalage de lem-s vives couleurs chercher a attirer “ I’attention des femelles, lesqueUes ne paraissaient indifferentes “ a ce manege, eUes nageaient avec une molle lenteur vers les “ mfiles et semblaient se complaire dans leur voisinage.” After the male has won his bride, he makes a little disc of froth by blo’mng air and mucus out of his mouth. He then collects the fertihsed 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 hatcheff I mention these par- ticulars because, as we shall presently see, there are fishes, the “ ‘Nature, May, 1873, p. 25. ‘Bull, de la Soc. d’Acclirnat.’ Pans, July 1869, and Jan. 1870. 342 The Descent of Man. Part IL. 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 habit of hatching them in their mouths might have been acquired. ' 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 intelhgible by the aid of sexual selection. We have next to enquire whether this view of the bright colours of certain male fishes having been acquired through sexual selection can, thi-ough the law of the equal transmission of characters to both sexes, be extended to those groups in which the males and females are brilhant 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 world — for instance, the Peacock Labrus (L. pavo), described,^ with pardonable exaggerar tion, as formed of polished scales of gold, encrusting lapis-lazuli, rubies, sapphires, emeralds, and amethysts — we 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 gold-fish {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 Bory do Snint Vincent, in ‘Diet. Class. d’Hist. Nat.’ tom. ii. 'PSe p. 151. Chap. XII. Fishes. 343 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.^^ 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 colom-ed without suffering some evQ or receiving some benefit from so great a change, and consequently without the intervention of natm’al selection. What, then, are we to conclude in regard to the many fishes, both sexes of which are splendidly coloured? Mr. Wallace^ believes that the species which frequent reefs, where corals and other brightly-coloured 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 brihiantly- coloured corals or other organisms for the fishes to resemble ; yet many species in the Amazons are beautifully colomed, and many of the carnivorous Cyprinidae in India are ornamented with “bright longitudinal hnes of various tints.” Mr. M'Clel- land, in describing these fishes, goes so far as to suppose that “ the peculiar briUiancy of their colours ” serves as “ a better “ mark for king-fishers, 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 har, 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 impalatable, as explained when treating of caterpillars; but it is not, I believe, known that any fish, at least any fresh-water fish, is rejected from being distasteful to fish-devouring animals On the whole, the most probable view in regard to the fishes, of which both sexes are briUiantly coloured, is that their colours were acquired by the males as a sexual ornament, and were transferred equally, or nearly so, to the other sex. Owing to some remarks on this subject, made in my work ‘ On the Variation of Animals under Domesti- cation,’ Mr. W. F. Mayers (‘ Chinese Notes and Queries,’ Aug. 1868, p. 123) has searched the ancient Chinese encyclopedias. He finds that gold-fish were first reared in confinement during the Sung Dy- nasty, which commenced a.d. 960. In the year 1129 these fishes abounded. In another place it is said that since the year 1.518 there has been “ produced at Hangchow a variety called the fire-fish, from its “intensely red colour. It is uni- “ versally admired, and there is not “ a household where it is not cul- “ tivated, m rivalry as to its colour, “ and as a source of profit.” ‘ Westminster Review,’ July 1867, p. 7. ‘ Indian Cyprinida:,’ by Mr. .1, M'Clelland, ‘ Asiatic Researches, vol. -xi.x. part li. 1839, p. 230. 344 The Descent of Man. Paet iJ, We have now to consider whether, when the male differs in a marked manner from the female in colour or in other orna- ments, 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.®^ 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. Giinther®® of a pipe-fish, which, with its reddish streaming filaments, is hardly distinguishable from the searweed 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 oi the salmon,®* the female, during the wliole 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 brightly-coloured 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 G. Pouchet, L’lnstitut. Nov. 1, 327, pi. liv. and .tv. 1871, p. 134. Ynrrell, ‘ Britifih Fishes,’ vol ■’'* ‘ Proc. Zoolog. Soc.’ 1865, p. ii. p. ' I Chap. XII. Fishes. 345 sexes of the bright coloured Crenilabrus massa and melons wort together in building their nests with sea-weed, shells, &c.®° But the males of certain fishes do all the work, and afterwards take exclusive charge of the young. This is the case with the dull- coloured gobies,®® 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 smooth-tailed stickleback (Q. leiurus) perform.s 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 chives 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.®'' The males of certain other fishes inhabiting South America and Ceylon, belonging to two distinct Orders, have the extra- ordinary habit of hatching within their mouths or branchial cavities, the eggs laid by the females.®® 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 spawning-season “ 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 breeding-season. With the various species of Ghromids, 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 oceUi, encircled “ with the most brilliant red.” Whether with all the species of Ghromids it is the male alone which sits on the eggs is not known. It is, however, manifest that the fact of the eggs being According to the observations of M. Gerbe ; see Gunther’s ‘ Record of Zoolog. Literature,’ 1865, p. 194-. ” Cuvier, ‘ Rfegne Animal,’ vol. .i. 1829, p. 242. See Mr. Warington’s most interesting description of the habits of the Qastcrosteus leiurus, in ‘ An- nals and Mag. of Nat. Hist.’ Novem- ber 1855. Prof. Wyman, in ‘ Proc. Boston Soc. of Nat. Hist.’ Sept. 15, 1857. Also Prof. Turner, in ‘ Journal of Anatomy and Phys.’ Nov. 1, 1866, p. 78. Dr. GUnther has likewise described other cases. 346 The Desce7it of M mi. Part 1L 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 blighter-coloured males would be far more influential on the character of the race, than the destruction of the brighter- coloured 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 than the females. In most of the Lophobranchii (Pipe-fish, Hippocampi, &c.) the males have either marsupial sacks or hemispherical de- pressions on the abdomen, in which the ova laid by the female are hatched. The males also shew great attachment to their young.® The sexes do not commonly differ much in colour; but Dr. Giinther beheves that the male Hippocampi are rather brighter than the females. The genus Solenostoma, however, offers a curious exceptional case,® for the female is much more vividly-coloured 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 brightly-coloured 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 yormg, are more brightly coloured than the females, and as here the female Sole- nostoma 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 period- ically 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 3® Yarrell, ‘ Hist, of British Kishes,’ vol. ii. 1836, pp. 329, 338. Dr. GUnthcr, since publishing in account of this species in ‘The Fishes of Zanzibar,’ by Col. Playfair, 1866, p. 137, has re-examined the specimens, and has given me the above information. Chap. XII, Fishes. 347 rxcordance viith the usual rule throughout the animal kingdom, the more attractive males. On the whole we may conclude, that with most fishes, in which the sexes differ in colour or in other ornamental charac- ters, the males originally varied, with their variations trans- mitted 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 bones — by the vibration of certain muscles attached to the swim- bladder, which serves as a resounding board — and by the vibra- tion of the mtrinsic muscles of the swim-bladder. By this latter means the Trigla produces pure and long-drawn 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 sound-producing apparatus, consisting of •small movable bones, with proper muscles, in connection with the swim-bladder.^^ The drumming of the TJmbrinas in the European seas is said to bo audible from a depth of twenty fathoms ; and the fishermen of Eochelle assert “ that the males “ alone make the noise during the spawning-time ; and that it “ is possible by imitating it, to take them without bait.”^ From this statement, and more especially from the case of Ophidium, it is almost certain that in this, the lowest class of the Yerte- brata, as with so many insects and spiders, sound-producing instruments have, at least in some cases, been developed through sexual selection, as a means for bringing the sexes together. ‘ Comptes Rendus.’ Tom. xlvi. 1858, p. 353. Tom. xlvii. 1858, p. ‘The American Naturalist,’ I>r. Anderson, ‘ Proc. Zoolog. 1873, p. 85. 2 A 354 pAnT II The Descent of Man. 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 my- self heard this in the case of a Trigonocephalus in S. America. Lacertilia. — The males of some, probably of many kinds of lizards fight together from rivalry. Thus the arboreal Anolis crintatellus 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 and this, as far as Dr. Gunther has been able to ascertain, is the general rule with lizards of all kinds. The males alone of the Cyrtodactylus rubidus of the Andaman Islands possesses pre-anal pores ; and these pores judging from analogy probably serve to emit an odour.®® The sexes often differ greatly in various external characters. The male of the above-mentioned Anohs 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 CopJwtis ceylanica, the femalb 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 tubercu- lata. 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 pairing-season. The female does not possess dven a rudiment of this appendage. In the An oils cristateilus, according to Mr. Austen, the tlnoat 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. Hero we Mr. N. L. Austen kept these Stoliczk.'i, ‘ Journal of Asiatic animals alive for a considerable Soc. of Bengal,’ vol. xxiiv. 1870, p. time; see ‘Land and Water.’ July 166. 1867, p. 9. Chap. XII. Reptiles. 355 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 httle lizards of the genus Draco, which ghde through the air on their rib- supported parachutes, and which in the beauty of their colours baffle description, are fm-nished with skinny appen- dages 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 like- wise have a low crest running along the neck ; and this is much more developed in the full-grown males, than in the females or young males.®’^ A Chinese species is said to live in pahs during the spring ; “ and if “ one is caught, the other falls from “ the tree to the ground, and allows “ itself to be captured with impu- “ nity,” — I presume from despah.®® There are other and much more remarkable differences between the sexes of certain lizards. The male of CeratopTiora 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 Fig. 3-t. ceratophora stoddartii rudimental. In a second species male ; lower figure, of the sarne genus a terminal scale forms a minute horn on the summit of the flexible appendage ; ^ All the foregoing statements nificent work on the ‘ Reptiles of and quotations, in regard to Cophotis, British India,’ Ray Soc. 1864, pp. Sitana and Draco, as well as the 122, 130, 135. following facts in regard to Cerato- «« Mr. Swinhoe, ‘Proc. Zoolog. phora and Cham.-cleon, are from Dr. Soc.’ 1870, p. 240. Gilnther himself, or from his mag- 356 The Descent of Man. Paet II. and in a third species ( C. Stoddartii, fig. 34) the whole appen- dage 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 birds, and apparently serve as ornaments. Fig. 35. Chamreloon bifurcus. Upper figurs, male; lower figure, female. In the genus Ohamjeleon 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 ot structure the female exhibits only a rudiment. Again, m Chap. XII. Reptiles. 357 Chamcelem 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 integu- ments of the body, so that they are identical in struc- ture with those of a bull, goat, or other sheath -horned ru- minant. Although the three horns differ so much in appearance from the two great pro- longations of the skull in C. yfurcus, we can haidly doubt that they serve the same general pur- pose in the economy of these two ani- mals. The first con- jectm-e, which will occur to every one, is that they are used by the males for fighting together; and as these animals are very quarrelsome,®^ this is probably a correct view. Mr. T. W. Wood also informs me that he once watched two individuals of Q. 'pumilus, fighting violently on the branch of a tree ; they flung thehr heads about and tried to bite each other ; they then rested for a time, and afterwards continued theh battle. 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 pale-greyish-grcen without spots.”’® We have seen that Fig. 36. Cbamasleon Owenii. Upper figure, male lower figure, female. ®® Dr. Bucholz, ‘ Monatsbericht ’<• Bell, ‘ History of British K. Preuss. Akad.’ Jan. 1874, p. 78. Reptiles,’ 2nd edit. 1849, p. 40. The Descent of Man. PiilT II. 358 tlie males alone of Sitana possess a throat-pouch ; and this is splendidly tinted with blue, black, and red. In the Prodotretxis Unuis of Chile the male alone is marked with spots of blue, green, and coppery-red.’^ In many cases the males retain the same colours throughout the year, but in others they become much brighter during the breeding-season ; 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.’^ 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 {Proctotrdus 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 appen- dages, 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 exposure of the females to danger during incubation. CHAPTER Xni. Secondaet Sexual Characters of Bires. Sexual differences — Law of battle — Special weapons — Vocal org.ans — Instrumental music — Love-antics and dances — Decorations, perm.anent and seasonal — Double and single annual moults — Display of ornaments by the males. Secondarv sexual characters are more diversified and con- spicuous 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 For Proctotretus see ‘ Zoology of the Voyage of the “ Beagle Keptiles,’ by Mr. Bell, p. 8. For the Lizards of S. Africa, see ‘ Zoology of S. Africa: Reptiles,’ by Sir Andrew Smith, pi. 25 and 39. For the Indian Calotes, see ‘ Reptiles of British India,’ by Dr Giinthcr, p. 143. Gilnther in ‘ Proc. Zoolog. Soc.’ 1870, p. 778, with a coloured figure. (Jhap. XIII. Birds. 359 with each other. They charm the female by vocal or instr ii- mental music of the most varied kinds. They are ornamented by aU sorts of combs, wattles, protuberances, horns, air-distended sacks, top-knots, naked shafts, plumes and lengthened feathers gracefully spiinging 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. Eamsay,* says of the Australian musk- duck (Biziura Idbata) 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 breeding-season, shot a female which had “ any smell of musk.” So powerful is this odour dui’ing the pahing-season, that it can be detected long before the bird can be seen.^ On the whole, birds appear to be the most sesthetic of aU 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 civihsed 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 humming-birds belonging to the genus Eustephanus, which inhabit i.he 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 humming-birds {Grypus), the beak of the male is serrated along the margin and hooked at the exti-emity, 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 gold- ' ‘ Ibis,’ vol. iii (new series) 1807, * Gould, ‘ Handbook to the Birds P- of Au.stralia,’ 1805, vo). ii. p. 383. 36o The Descent of Man. Part II finch (Carduelis elegans), for I am assured by Mr. J. Jermer "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 t,bi« afterwards led to slightly changed habits of life. Law of Battle. — Almost all male birds are extremely pug- nacious, 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 humming-bird, is one of the most quarrelsome. Mr. Gosse* 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 of another genus of humming-bird, 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.”^ With Waders, the males of the common water-hen ( QaMnula 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 aU the time looking on as a quiet spec- tator.® Mr. Blyth informs me that the males of an aUied bii’d (Gallicrex cristatus) are a third larger than the females, and are so pugnacious during the breeding-season, 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 pui'pose, for instance, the bulbuls {Pycnonotus hxmorrhous) which “ fight with great “ spirit.”® 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 “ Quoted by Mr. Gould, ‘ Intro- duction to the Trochilidos,’ 1861, V- 29. * Gould, ibid. p. 52. ’ W. Thompson, ‘ Nat. Hist, of Ireland : Birds,’ vol. ii. 1850, p. 327. “ Jerdon, ‘Bii-ds of India,’ 1863, vol. ii. p. 96. Chap. XIII. Law of Battle. 361 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 Fie, rr. The Eu£F or JUnchetes pusaas (Itou) Crehm’s ‘ThierlebenO. 3^2 Pabt IL The Descent of Man. instaiico 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 orna- ment. 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.'^ Of the pugnacity of web-footed birds, two instances will sufS.ce : in Guiana “ bloody fights occur during the breeding-season between the males of the wild “ musk-duck (^Cairina moschata)] and where these fights have “ occurred the river is covered for some distance with feathers.”® Birds which seem ill-adapted for fighting engage in fierce con- flicts ; 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 (^Picus awraias), although “the “ hens are followed by even half a dozen of their gay suitors.” ® The males of many birds are larger than the females, and tliis 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 musk-duck (Biziura) and the male Cincloramphus cruralis (allied to our pipits) are by measurement actually twice as large as theii- respective females.^ With many other bii-ds the females are larger than the males ; and as formerly remarked, the explana- tion often given, namely, that the females have most of the work in feeding their young, will not suffice. In some few cases, as we shaU hereafter see, the females apparently have acquired their greater size and strength for the sake of conquering other females and obtaining possession of the males. The males of many gallinaceous birds, especially of the poly- gamous kinds, are fui-nished with special weapons for fighting with their rivals, namely spurs, which can be used with fearful ’’ Macgillivray, ‘ Hist. Brit. Birds,’ vol. iv. 1852, pp. 177-181. ® Sir K. Schoniburgk, in ‘Journal of R. Geograph. Soc.’ vo). xiii. 1843, p. 31. ® ‘Ornithological Biography,’ vol. i. p. 191. For pelicans and snipes, see vol. iii. pp. 138, 477. Gould, ‘ Handbook of Birds of Australia,’ vol. i. p. 395 ; vol. ii. p. 383 Chap. XII I. Law of Battle. 363 effect. It has been recorded by a trustworthy writer that in Derbyshire a kite struck at a game-hen accompanied by her chickens, when the cock rushed to the rescue, and drove his spur right through the eye and skuU 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 injm-ed. 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 bii’d fought with undaunted courage until he received his death- stroke. 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.^“ An Indian partridge ( Ortygornis gularis), the male of which is furnished with strong and sharp spurs, is so quarrel- some, “ that the scars of former fights disfigure the breast of “ almost every bird you kill.” “ The males of almost all galLmaceous birds, even those which are not furnished with spurs, engage during the breeding-season in fierce conflicts. The Capercailzie and Black-cock (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 Eussia he has seen the snow all bloody on the arenas where the capercailzie have fought ; and the black-cocks “ 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 love- dances and love-songs of the Black-cock 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 bu-d appears like a frantic ” Mr. Hewitt in the ‘Poulti-y Nat. Hist.’ vol. xiv. 1854, p. 63. Boob by Tegetmeier,’ 1866, p. 137. Jerdon, ‘Birds of India’ vol. Ijiynrd, ‘Annals and Mag. of iii. p. 5’ 4. 3^4 TIu Descent of Man. Pabt IL “ creature.” At such times the black-cocks are so absorbed that they become almost blind and deaf, but less so than the caper- cailzie : 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 black-cock, in order to prove his strength over several antagonists, will visit in the course of one morning several Balz-places, which remain the same during successive years.^* The peacock with his long train appears more like a dandy than a warrior, but he sometimes engages in fierce contests : the Eev. 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 St. John’s tower. The spur, in those gallinaceous birds which are thus provided, is generally single ; but Polyplectron (see fig. 51, p. 397) has two or more on each leg; and one of the Blood-pheasants {ithwjinis cruentus) has been seen with five spui-s. The spurs are generally confined to the male, being represented by mere knobs or rudi- ments in the female ; but the females of the Java peacock {Pavo muticus) and, as I am informed by Mr. Blyth, of the small fire- backed pheasant (^Euplocamus erytliropthalmus) possess spurs. In GaUoperdix it is usual for the males to have two spurs, and for the females to have only one on each leg.^® Hence spurs may be considered as a masculine structure, which has been occasion- ally more or less transferred to the females. Like most other secondai’y sexual characters, the spurs are highly variable, both in number and development, in the same species. Various birds have spurs on their wings. But the Egyptian goose (^Chenalopex oegyptiacus) 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 spur-winged goose, Plectropt&rm gambensis, the males have much lai'ger spurs than the females; and they use them, as I am informed by Mr. Bartlett, in fighting together, so that, in this case, the wing-spurs serve as sexual weapons ; but according to Livingstone, they are chiefly used in the defence of the young. The Palamedea (flg. 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 spur-winged rails, Brehm, ‘ Illust. Thierleben,’ Sweden,’ &c., 1867, p. 79. 1867, B. iv. s. 351. Some of the “ Jerdon, ‘Birds of Indi.i: on foregoing statements are taken from Ithaginis, vol. iii. p. 523 ; on Gallo- L. Lloyd, ‘ The Game Birds of perdix, p. 541. Chap. XIII. Law of BattCe. 365 are larger in the male than in the female.^*^ In certain plovers, however, the wing-spurs must be considered as a sexual cha- , Fig. 38. Palamcdca comnta (from Erehm). shewing the double wing-spurs, and the I lllamcnt on the head. C: 'ir \) r' ' 366 The Descent of Man. Part IL meter. Thus in the male of our common peewit ( Vanellus cris- tatus) the tubercle on the shoulder of the wing becomes more prominent dui-ing the breeding-season, and the males fight together. In some species of Lobivanellus a similar tubercle becomes developed during the breeding-season “into a short “ horny spur.” In the Australian L. hiatus 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.^'^ The season of love is that of battle ; but the males of some birds, as of the game-fowl and ruff, and even the young males of the wild turkey and grouse,^® 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 {Esti'elda 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 en- sues.'® When many males congregate at the same appointed spot and fight together, as in the case of grouse and various other bii-dB, they are generally attended by the females,®® which after- wards pair with the victorious combatants. But in some cases the paii’ing precedes instead of succeeding the combat : thus accord- ing to Audubon,®' several males of the Virginian goat-sucker {Caprimulgus virginianus) “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 di’ivcs medea, Brehm’s ‘ Thierleben,’ B. iv. s. 740. See also on this bird Azara, ‘Voyages dans I’Amerique merid.’ tom. iv. 1809, pp. 179, 253. *' See, on our peewit, Mr. E. Carr 111 ‘ Land and Water,’ Aug. 8th, 1868, p. 46. In regard to Lobi- vanellus, see Jerdon’s ‘ Birds of India,’ vol. iii. p. 647, and Gould’s ‘ Handbook of Birds of Australia, vol. ii. p. 220. For the Holopterus, see Mr. Allen in the ‘Ibis,’ vol. v, 1863, p. 156. Audubon, ‘ Ornith. Biography, vol. ii. p. 492 ; vol. i. pp. 4-13. Mr. Blyth, ‘ Land and Water, 1867, p. 212. Eichardson on Tetrao umhelhis ‘Fauna Bor. Amer. : Birds,’ 1831, p. 343. L. Lloyd, ‘ Game Birds of Sweden,’ 1867, pp. 22, 79, on the capercailzie and black-cock. Brehm, howevei', asserts (‘ Thierleben,’ &c., B. iv. s. 352) that in Germany the grey-hens do not generally attend the Balzen of the black-cocks, 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 tlie grey-hens in Samdinavia, and with other species in N. Americ.a. ‘ Ornithological Biography, vol. ii. p. 275. Chap. XEH. Law of Battle. 367 “ 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 red-deer in Scotland. When two males contend in presence of a smgle 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.“ 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 breeding-season, and which are sedulously displayed before the females. The males also endeavour to charm or excite their mates by love-notes, 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 un- consciously prefer them. In the case of Tetrao umbellus, a good observer ^ goes so far as to believe that the battles of the males “ 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 Tttrao cupido of the Uniteo States, about a score of males assemble at a particular spot, ano strutting about, make the whole air resound with their extra ordinary 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 field-starlings of the United States (Sfurnella ludoviciana) the males engage in fierce conflicts, “ but at the sight of a female “ they all fly after her, as if mad.” “ ” Breimi, ‘ Thierleben,’ &c., B. i^. 1867, p. 990. Audubon, ‘ Ornith. Biography,’ vol. ii. p. 492. ‘Land and Water,’ July 25th, 1868, p. 14. Audubon’s ‘ Ornith olog. Bio- graphy ;’ on Tetrao cupido, vol. ii, p. 492 ; on the Sturnus, vol. ii. p 219. 368 The Descent of Man. Pakt n. Focal and instrumental music. — 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 nestling- birds. Audubon “ relates that a night-heron {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 ; ” 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 water-fowl, 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 humming-bird chirps, in triumph over a defeated rival. The true song, however, of most birds and various strange cries are chiefly uttered during the breed- ing-season, and serve as a charm, or merely as a call-note, 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 song-birds 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 amorous notes, “ which, by instinct, the female knows, and repairs to the spot to “ choose her mate.”^'' 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.” There can be no doubt that birds closely attend to each other’s song. Mr. Weir has told mo ot ‘ Ornithological Biograph.’ vol. V. p. 601. The Hon. Daines Barrington, ‘ Philosoph. Transact.’ 1773, p. 252. S' ‘ Ornithological Dictionary,’ 1833, p. 475. ‘ Naturgeschichto der Stuben- vogel,’ 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 s.ame “ room.” Chap. XIII. Vocal Music. 369 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, con- sisting 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.^* Bar- rington, 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. Bird-fanciers match their birds to see which will sing longest; and I was told by Mr.Yarrellthat a first-rate bird will sometimes sing till he drops down almost dead, or according to Bechstem,®“ 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 canary-bird has been de- scribed 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 bird-catchers; a male, m 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 bird-catcher 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, ” ‘ Philosophical Transactions,’ ‘ Naturgesch. der Stubenvogel,’ 1773, p. 263. White’s ‘ Natural 1840, s. 252. History of Selborne,’ 1825, vol. i. p. 3‘ Mr. Bold, ‘ Zoologist,’ 1843-44. 246. p. 659. 2 B 370 TJie Descent of Man. Part IL 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 widow- hood, 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,®* for this disturbs all the usual functions connected with the repro- duction of the species. Many instances have already been given of the partial transference of secondary mascuUne 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 ha,s also been argued, that the song of the male cannot serve as a charm, be- cause the males of certain species, for instance of the robin, sing during the autumn.®* 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 ob- viously for pleasure ? The cat plays with the captured mouse, and the cormorant with the captured fish. The weaver-bird (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 breeding-season 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 as- semblage during the autumn.®* Hence it is not at all surprising that male birds should continue singing for their own amuse- ment after the season for courtship is over. 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 acquii-e the song of their foster parents,*® and sometimes that of their neighbours.** 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,’*’ ” D. Barrington, ‘Phil. Transact.’ 1773, p. 262. Bechstein, ‘Stuben- vogel,’ 1840, s. 4. 3® This is likewise the case with the water-ouzel, see Mr. Hepburn in the ‘Zoologist,’ 1845-1846, p. 1068. L. Lloyd, ‘ Game Birds of Sweden,’ 1867, p. 25. Barrington, ibid. p. 264. Bechstein, ibid. s. 5. Bureau de la Malle gives a curious instance (‘Annales des Sc. Nat.’ 3rd scries. Zoolog. tom. i. p. 118) of some wild blackbirds in his garden in Paris, which naturally learnt a republican air from a caged bird. ** Bishop, in ‘ Todd’s Cyclop, of Anat. and Phys.’ vol. iv. p. 1496. Chap. XIII. Vocal Mzisic. 371* though they never sing, and do not naturally modulate their- voices to any great extent. Hunter asserts that with the true songsters the muscles of the larynx are stronger in the males t.hn.Ti 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 species sing so much better and more continuously than the females. It is remarkable that only small birds properly sing. The Australian genus Meuura, however, must be excepted ; for the Menura Alberti, which is about the size of a half-grown tui’key, not only mocks other birds, but “ its own whistle is exceedingly “ beautiful and varied.” The males congregate and form “ cor- rohorying places,” where they sing, raising and spreading their tails like peacocks, and drooping their wings.®® It is also remark- able 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 plain-coloured. The kingfisher, bee-eater, roller, hoopoe, woodpeckers, &e., utter harsh cries ; and the brilliant bii'ds of the tropics are hardly ever songsters.^® 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 one such means. In some birds the vocal organs differ greatly in the two sexes. In the Tetrao cupido (fig. 39) the male has two bare, orange- coloured sacks, one on each side of the neck; and these are largely inflated when the male, during the breeding-season, 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 air-sacks on each side ot 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.” The As stated by Barrington in ‘ Philosoph. Transact.’ 1773, p. 262. Gould, ‘ Handbook to the Birds of Australia,’ vol. i. 186.5, pp. 308- 310. See also Mr. T. W. Wood in the ‘Student,’ April 1870, p. 125. ■"> See remarks to this eflect in Gould’s ‘ Introduction to the Trochi- lida:,’ 1861, p. 22. “ ‘ The Sportsman and Naturalist in Canada,’ by Major W. Ross King, 1866, pp. 144-146. 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 ear-tufts or neck- plumes are erected, so that they meet over the crown of the head. See his drawing, fig. 39. 2 B 2 372 The Descent of Man. Part II. male of another kind of gronse {Tetrao urophasianus), whilst conrting 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 neck- feathers erect, his wings lowered, and buzzing on the gound, 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.'* ■>* Richardson, ‘ Fauna Bor. American : Birds,’ 1831, p. 359. Audubon bid. vol. iv. p. 507. Chap. Xin. Vocal Music. 373 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 coimected with the utterance during the breeding- Fig. JO. Tbe Umbrella-bird or Cerbalopierus ornatus male irom Biehm). season of a peculiar sound resembling “oak.”^® A crow-like bird inhabiting South America (Cephulopterus ornatus, fig. 40) is called the umbrella-bird, from its immense top knot, formed of The following papers have been lately written on this subject : 1 rof. A. Newton, in the ‘ Ibis,’ 1862, p. 107 , Dr. Cullen, ibid. 186.'), 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 Austra- lian 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. 374 Part IL The Descent of Man. bare white quills surmounted by dark-blue plumes, which it cau 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 scalo- like 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 neck-appendage are rudimentary in the female.''^ The vocal organs of various web-footed and wading birds are extraordinarily complex, and differ to a certain extent in the two sexes. In some cases the trachea is convoluted, hke 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.^® In one of the ducks, however, namely Anas functata, the bony enlargement is only a Little more developed in the male than in the female.^® But the meaning of these differences in the trachea of the two sexes of the Anatidse 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.^'^ In both sexes of one of the cranes ( Gras virgd) the trachea penetrates the sternum, but presents “ certain “ sexual modifications.” In the male of the black stork there is also a well-marked sexual difference in the length and curvature of the bronchi.^® Highly important structures have, therefore, iu these cases been modified according to sex. It is often difficult to conjecture whether the many strange cries and notes uttered by male birds dmiag the breeding- season, serve as a charm or merely as a call to the female. The soft cooing of the turtle-dove and of many pigeons, it may be presumed, pleases the female. When the female of the wild ** Bates, ‘ The Naturalist on the Amazons,’ 1863, vol. ii. p. 284; Wallace, in ‘ Proc. Zool. Soc.’ 1850, t , 206. A new species, with a still larger neck-appendage ((7. pcndu- figer), has lately been discovered, see ‘ Ibis,’ vol. i. p. 457. Bishop, in Todd’s ‘Cyclop, of \nat. and Phys.’ vol. iv. p. 1499. Prof. Newton, ‘Proc. Zot.og. Soc.’ 1871, p. 651. 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 con- stantly present, so that perhaps they are now tending towards abortion. ‘ Elements of Comp. Anat.’ by R. Wagner, Eng. translat. 1845, p. 111. With respect to the swan, as given above, Yarrell’s ‘ Hist, of British Bird.s,’ 2nd edit. 1345, vol, iii. p. 193. Chap. XIII, Instrumental Music. 375 turkey utters her call in the morning, the male answers by a note which differs from the gobbhng noise made, when with erected feathers, rustling wings and distended wattles, he puffs and struts before her.‘® The spel of the black-cock 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 black-cock 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.®® The voice of the common rook is known to alter during the breeding-season, and is therefore in some way sexual.®^ 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 this point we shall recur when we treat of quadrupeds. 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. Turkey-cocks scrape their wings against the ground, and some kinds of grouse thus produce a buzzing sound. Another North American grouse, the Tetrao umlellus, 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. E. 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 Kahj- pheasant, 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 tittle black-weavers (Ploceus?) congregate in a small party on the bushes round a small open space, and sing and glide through C. L. Bonaparte, quoted in the Sweden,’ &c., 1867, pp. 22, 81. ‘Naturalist Library: Birds,’ vol. Jenner, ‘ Philosoph. Transoo- siv. p. 126. tions,’ 1824, p. 20. L. Lloyd, ‘ The Game Birds of 376 Part II The Descent of Man. the air with quivering wings, " which make a rapid whirring “ sound hke a child’s rattle.” One bird after another thus performs for hours together, but only during the courting-seasom At this season and at no other time, the males of certain night-jars (Capri- mulgus) make a strange booming noise with their wings. The various species of wood-peckers 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 pro- duced is audible at a considerable distance, but cannot be described ; and I feel sure that its source would never be con- jectured by any one hearing it for the first time. As this jarring sound is made chiefly during the breedmg-season, it has been considered as a love-song ; 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 iUpupa epops) combines vocal and instrumental music ; for during the breeding-season 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 eorrect sound.” If the beak is not thus struck against some object, the soimd 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.®* 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, neigh- ing, or thundering noise (as expressed by different observers) made by the common snipe (Scolopax gallinagd) must have sur- prised every one who has ever heard it. This bird, during the paii’ing-season, flies to “ perhaps a thousand feet in height,” and For the foregoing facts see, on Birds of Paradise, Brehm, ‘ Thierleben,’ Band iii. s. 325. On Grouse, Kichardson, ‘ Fauna Bor. Americ. ; Birds,’ pp. 343 and 359 ; Major W. Ross King, ‘ The Sports- man in Canada,’ 1866, p. 156; Mi'. Raymond, in Prof. Cox’s ‘ Geol. Survey of Indiana,’ p. 227 ; Audu- bon, ‘ American Ornitholog. Bio- graph.’ vol. i. p. 216. On the Kalij-phcasant, Jordon, ‘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 Night-jar, Audubon, ibid, vol. ii. p. 255, and ‘ American Natu- ralist,’ 1873, p. 672. The English Night-jar likewise makes in the spring a curious noise during its rapid flight. Chap. XIII. Instmmental Music. 377 after zig-zagging about for a time descends to the earth in a cm’ved 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 sabre-shaped shaft Fig. 41. Outer tail-feather of Scolopax gallinago (from ■ Proc. Zool. Soc.’ 1868). 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 tban in the female, and emit a deeper note. In some species, as in B. frenata (fig. 42), four feathers, and in S. javensis (fig. 43), no less than eight on each side of the tail ai’e greatly modified. Different tones are emitted by the feathers of the different species when waved through the air ; and Fig. 42. Outer tail-feather of Scolopax frenata. Fig. 43. Outer tail-feather of Scolopax javensis. ... . the Scolopax Wilsonii of the United States makes a switching noise whilst descending ranidlv to the earth.®^ In the male of the Chamcepetes unicolor (a large gallinaceous bird of America) the first primary wing-feather is arched towards the tip and is much more attenuated than in the female. In an allied bird, the Penelope niyra, 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.®* See M. Meves’ interesting paper in ‘Proc. Zool. Soc.’ 1858, p. 199. For the habits of the snipe, Macpllivray, ‘ Hist. British Birds,’ vol. iv. p. 371. For the American snipe, Capt. Blakiston, ‘Ibis,’ vol, v. 18G3, p. 131. Mr. Salvin, in ‘ Proc. Zool. Soc.’ 1867, p. 160. I am much in- debted to this distinguished orni- thologist for sketches of the feathers of the Chama'petes, and for other information. 378 The Descent of Man. Part II. The male alone of one of the Indian bustards (^Sypheotides awrfiMs) has its priraarywing-feathers greatly acuminated ; and the male of an allied species is known to make a humming noise whilst courting the female.“ In a widely different group of birds, namely Humming-birds, the males alone of certain kinds have either the shafts of their primary wing- feathers broadly dilated, or the webs abruptly excised towards the extremity. The male, for in- stance, of Selu!>phonis 2‘ldtycercus, when adult, has the first primary wing-feather (fig. 44), thus excised. Whilst flying from flower to flower he makes “ a shrill, almost whist- ling noise but it did not appear to Mr. Salvin that the noise was intentionally made. Lastly, in several species of a sub-genus of Pipra or Manakin, the males, as described by Mr. Sclater, have their secondary wing- feathers modified in a still more remarkable manner. In the brilliantly-coloiu’ed P. deliciosa the first three secondaries are thick-stemmed and curved towards the body ; in the fourth and fifth (fig. 45, a) the change is greater; and in the sixth and seventh (6, 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, /) in the female. Even the bones of the wing, which support these singular feathers in the male, are said by Mr. Eraser to be much thickened. These little birds make an extraordinary noise, the first “ sharp note being not unlike the " crack of a whip.” The diversity of the sounds, both vocal and instrumental, made by the males of many birds during the breeding-season, 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 con- clusion 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, miglit have been improved Jei'don, ‘ Birds of India,’ vol. Sclater, in ‘ Proc. Zool. Soc.’ iii. pp. 618, 621. 1860, p. 90, and in ‘Ibis.’ vol. iy. Gould, ‘Introduction to the 1802, p. 175. Also Salvin, in Trochilidcc,’ 1861, p. 49. Salvin, ‘ Ibis,’ 1860, p. 37. ‘Proc. Zoolog. Soc.’ 1867, p. 160. Fig. 44. Primary wing-feather of a Humming-bird, the Selasphorus pla- tycercus (from a sketcli by Mr. Sal- vin). Upper figure, that of mule; lower figure, corresponding feather of female. Chap. XIII. Vocal and Instrumental Mtisic. 379 Mo 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 d e / ofl wing-fcathcrs of Pipra deliciosa (from Mr. Sclater, In ‘ Proc. Zool. ooc. 1860). The three upper feathers, o, 6, c, from the male; the three lower corre- feathers, d, e,f, from the female. a ana a, fifth secondary wing-feather of male and female, upper surface. 0 and e, sixth secondary, upper surface, c and /, seventh secondary, lower surface. 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 bo 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 Descent of Man. Part tl. 380 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 trumpet-like cry of certain water-fowl, the cooing of the turtle- dove, 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 tom- toms and the shrill notes of reeds, please the ears of savages. Sir S. Baker remarks,®® 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 discordant music to “ aU other.” Love-Antics and Dances. — 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 breeding- season on a selected level spot, and here they run round and round in a circle of about fifteen or twenty feet in diameter, sc that the ground is worn quite bare, like a fairy-ring. In these Partridge-dances, as they are called by the hunters, the birds assume the strangest attitudes, and nin 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 carrion-vultures ( Cathartes jota) the same naturalist states that “the gesticulations and parade of the “ males at the beginning of the love-season are extremely “ ludicrous.” Certain birds perform their love antics on the wing, as we have seen with the black Africsin weaver, instead of on the ground. During the spring our little white-throat {Sylvia cinerea) often rises a few feet or yards in the air above some bush, and “ flatters 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 hengalensis') at such times “ rises perpen- “ dicularly into the air with a hurried flapping of his wings, “ raising his crest and puflSng out the feathers of his neck and “ breast, and then di’ops to the ground he repeats tliis manoeuvre several times, at the same time humming in a peculiar tone. Such females as happen to be near “ obey this ‘® ‘Thn Nile Tributaries of Abyssinia,’ 1867, p. 203. Chap, XIII. Love Antics and Decoration. 381 “ saltatory summons,” and when they approach he trails his wings and spreads his tail Like a turkey-cock.®® But the most curious case is afforded by three allied genera of Australian bix-ds, the famous Bower-birds,— no doubt the co- descendants of some ancient species which first acquired the strange instinct of constructing bowers for performing their loTe-antics. The bowers (fig. 46), which, as wo 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®® the habits of some Satin Bower-birds 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 “ kinH of note, set all his feathers erect, run round the bower and “ become so excited that his eyes appear ready to start from his “ head; 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 “ play-houses ” of another species, the Great Bower-bhd, which was seen “ amusing itself by flying “ backwards and forwards, taking a shell alternately &om 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 Fawn-breasted species, is nearly four feet in length, eighteen inches in height, and is raised on a thick platform of sticks. Decoration. — 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 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, Au- dubon, ‘ Ornith. Biography,’ vol. ii. p. 51, and vol. iii. p. 89. On the White-throat, Macgillivray, ‘ Hist. British Birds,’ vol ii. p. 354. On more brightly-coloured than the the Indian Bustard, Jerdon, ‘ Birds of India,’ vol. iii. p. 618. Gould, ‘ Handbook to the Birds of Australia,’ vol. 1. pp. 444, 449, 455. The bower of the Satin Bower-bird may be seen in the Zoological Society’s Gardens, Re- gent’s Park. 382 The Descent of Man. ^ Part II. male.; A.s "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.”^ The ornaments, as mentioned See remarks to this effect, on ‘ Feeling of Beauty among Animals,’ by Mr. J. Shaw, in the ‘Athemeum,’ Nov. 2-Uh, 1 8til>, p. 08 1 . is* o I ^ I •3 eck of dirt. One observer, who kept several pairs abve, did not doubt that the display of the male was intended to please the female.®* The Gold and Amherst pheasants dm’ing 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.®* They likewise turn their beautiful tails and tail-coverts a little towards the same side. Mr. Bartlett has observed a male Polyplectron (fig. 51) in the act of court- ship, and has shewn me a specimen stuffed in the attitude then assumed. The tail and wing-feathers of this bird are ornamented with beautiful oceUi, tike 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 thi-oat and breast. But the breast of the Polyplectron is obscurely coloured, and the oceUi are not confined to the tail- feathers. Consequently the Polyplecti'on does not stand in front of the female ; but he erects and expands his tail-feathers a tittle 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 ‘ Journal of R. Geograph. Soc.’ ®° Mr. T. W. Wood has given vol. X. 1840, p. 236. (‘ 'I’he Student,’ April 1870, p. 115) •* ‘ Annals and Mag. of Nat. Hist.’ a full account of this m.-mner of vol. xiii. 1854, p. 157 ; also Wallace, display, by the Gold phea.«!Bnt and ibid. vol. XX. 1857, p. 412, and ‘The by the Japanese pheasant, Ph, Malay Archipelago,’ vol. ii. 1869, p. versicolor; and he calls it the l.ateral 252. Also Dr. Bennett, ns quoted or one-sided display, by Brehm, ‘ Thierlebcn,’ B. iii. s. 326. Chap. XIII. Display by the Male. 397 eyes of the admiring female in one grand bespangled expanse. To whichever side she may tiu-n, the expanded wings and the obUquely-held 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 f;s. 61. Polyplectron chinquis, male (T. W. Wood). 398 The Descent of Man. Part EL ■which is opposite to the female, and which would othejrwise be concealed, so that nearly all the beautifully spotted feathers are exhibited at the same time. The Argus pheasant affords a much more remarkable case. The immensely developed secondary wing-feathers are confined to the male ; and each is ornamented with a row of from twenty to twenty-three 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 she'ws himself off before the female. He then erects his tail, and expands his -wing-feathers 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 -wing-feathers (as Mr. Bartlett has seen), and then pre- sents 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 margin of the fan. The ocelli on the -wing-feathers are wonderful objects ; for they are so shaded that, as the Duke of Argyll remarks,®® they stand out hke balls lying loosely within sockets. When I looked at the specimen in the British Museum, which is mounted with the wings expanded and trailing do-wnwards, 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 ha-ve been she-wn 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 moans of sexual selection ? But it will bo convenient to defer gi-vtng an answer to this question, until we treat in the next chapter of the principle of gradation. The foregoing remarks relate to the secondary wing-feathers, but the primary wing-feathers, which in most gallinaceous birds are uniformly coloured, are in the Argus pheasant equally wonderful. They are of a soft brown tint with numercus dark ‘ The Reign of Law,’ 1867 p. 203. Chap. XIII. 399 Display by the Male. soots each of which consists of two or three black dots with a grounding dark ssone. But the chief ornament is a space parallel to the dark-blue shaft, which in outhne forms a perfect second feather lying within the true feather. This inner part is coloured of a lighter chesnut. and is thickly dotted with minuta Fig. 63. Side view of male Argue pheasant, whilst displaying before the female. Observed and sketched from nature by Mr. T. W. Wood. 400 paet n. The Descent of Man. white points. I have shewn tliis 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 con- clude that this is the case, as the secondary and primary wing- feathers are not at all displayed, and the ball and socket orna- ments are not exhibited in full perfection, until the male assumes the attitude of courtship. The Argus pheasant does not posse.ss briUiant 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 conclusion which I for one will never admit. Although BO many pheasants and allied gallinaceous birds carefully display their plumage before the females, it is remark- able, as Mr. Bartlett informs me, that this is not the case with the dull-coloured Eared and Cheer pheasants ( Urossoptilon 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 strongly-characterised plumage are more quarrelsome than the dull-coloured species belonging to the same groups. The goldfimch, for instance, is far more pugnacious than the Linnet, and the blackbird than the thrush. Those birds which undergo a seasonal change of plumage like- wise becomes much more pugnacious at the period when they are most gaily ornamented. No doubt the males of some obscurely-coloured birds fight desperately together, but it appears that when sexual selection has been highly influential, Chap. XIII. 401 Display by the Male. 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 bi-ilUantly coloured birds have had their feathers specially modified for the sake ot 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 aU the Bri tish Fringillidae and Emberizidse. 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 pufis 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 edgmgs. 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 dark- tipped wing-feathers 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- aUied male siskin, for he would not thus add to his beauty. 2 n ‘ 402 Past II. The Desce7it of Man. Most of the British Buntings are plain coloured birds ; but in the spring the feathers on the head of the male reed-bunting {Emheriza schoeniculus) acquire a fine blaok 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 jet-black upper tail-coverts, each of the latter being marked with three large con- spicuous oval spots of white.®'^ This species, vs^en courting the female, slightly spreads out and vibrates these parti-coloured tad-coverts in a very peculiar manner. The male Amadina Lathami behaves very differently, exhibiting before the female his brilhantly spotted breast, scarlet rump, and scarlet upper tail-coverts. I may here add from Dr. Jerdon that the TridiRTi bulbul (^Pycnonotus hxmorrhous') has its under tail-coverts 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.”®® The crimson under tail-coverts of some other birds, as with one of the woodpeckers. Ficus 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 bronze-winged 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 ii-idescent 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 aU the males of the same species display themselves in exactly the same maimer, 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 ex- panded and quivering tail-feathers, he seems the very emblem of pride and vanity. For the description of these p. 417. birds, see Gould’s ‘ Handbook to the ‘Birds of India,’ vol. il. p. 96. Birds of Australia,’ vol. i. 1865, Ohap. XIII. Display by the Male. 403 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 night-jar (Cosmetornis), which diu'ing the pairing-season has one of its primary wing-feathers 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 wing-feathers of the male Argus pheasant are said “ almost entirely to deprive “ the bird of flight.” The flne plumes of male birds of paradise trouble them during a high wind. The extremely long tail- feathers of the male widow-birds (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 in- convenience 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 wing-feathers of the Argus pheasant must render them an easier prey to any prowling tiger-cat, 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 compa- ratively tame females, or than the young and as yet unadorned males.®** 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 Mil each other, suffer from possessing certain ornaments. Cock-fighters trim the hacMes 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. On the Cosmetornis, see Living- widow-bird, Barrow’s ‘ Travels m stone’s ‘ Expedition to the Zambesi,’ Africa,’ vol. i. p. 243, and ‘ Ibis,’ 1865, p. 66. On the Argus pheasant, vol. iii. 1861, p. 133. Mr. Gould, Jardine’s ‘Nat. Hist. Lib.: Birds,’ on the shyness of male birds, ‘ Hand- vol. liv. p. 167. On Birds of hook to Birds of Australia,' vol. i. Paradise, Lesson, quoted by Brehm, 1865, pp. 210, 457. ‘ Thierleben,’ B. iii. s. 325. On the 2 D 2 404 Pab7 it. The Descent of Man. “ 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.” Young turkey-cocks 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 facta 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 even sometimes more important than success in battle. CHAPTEE XIY. Brans — con tinned. Choice exerted by the female — Length of courtship — Unpaired birds — Mental qualities and taste for the beautiful — Preference or antipathy shewn by the female for paidicular males — Variability of birds — Varia- tions sometimes abrupt — Laws of variation — Formation of ocelli — Gradations of character — Case of Peacock, Argus pheasant, and Urosticte. 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 breeding-season. It is the male alone who elaborately displays his varied attractions, and often performs strange antics on the groimd 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 ex- cite or charm her in various ways ; and this is the opinion of all those who have carefully studied the habits of livibg 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 afSrmative by much direct and indirect evidence. It is far Tegetmeier, ‘ The Poultry Book,’ 1866, p. 139. Chap. XIV. Length oj Courtship. 405 more difficult to decide what qualities determine the choice of the females • but here again we have some dii-ect and indirect evi- dence that it u to a large extent the external attractions of the male; though no doubt his vigour, courage, and other mental qualities come into play. We will begin with the indirect evidence. Length of Courtship.— 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 pro- longed affair, and partly on reiteration in the act of pairing. Thus in Germany and Scandinavia the balzing or leks of the black-cocks last from the middle of March, all through April into May. As many as forty or fifty, or even more birds con- gregate 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,* follow nearly the same habits. The fowlers discover the hillocks where the ruffs con- gregate 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 Eock; and the natives of New Guinea know the trees where from ten to twenty male birds of paradise in full plumage congi’egate. 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 breeding-season, and perform for houi-s their graceful evolutions. Large n umbers 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 largo rats,” puffing out their feathers, flapping their wings, and uttering the strangest cries.^ * Nordmau describes (‘ Bull. Soc. Imp. des N.at. Moscou,’ 1861, tom. Mxiv. p. 264) the balzen of Tetrao ttrcgalloides in Amur Land. He estimated the number of birds assembled at above a hundred, not counting the females, which lie hid in the surrounding hushes. The noises uttered differ from those of T. urogallus. “ 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. Richard- son, ‘ 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 Nat. Hist.’ vol. xx. 1857, p. 412. On the snipe, Lloyd, ibid. p. 221. 406 The Desce7it of Man. Part IL Some of the above birds, — the black-cock, capercailzie, pheasant-grouse, ru£F, Solitary sm'pe, 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 lyre-bird {Menwra superha) fowas “small round hillocks,” and the M. Alberti scratches for itself shallow holes, or, as they are called by the natives, corrohorying places, where it is believed both sexes assemble. The meetings of the ilf. superha are some- times very large ; and an account has lately been published * 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 hun- dred and fifty of the magnificent lyre-cocks, “ ranged in order of “ battle, and fighting with indescribable fury.” The bowers of the Bower-birds are the resort of both sexes during the breeding- season ; 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.'* The common magpie ( Corvus pica, Lion.), as I have been in- formed by the Eev. W. Darwin Fox, used to assemble from all parts of Delamere Forest, in order to celebrate the “ great mag- pie marriage.” Some years ago these birds abounded in extra- ordinary 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 ® Quoted by Mr. T. W. Wood in of Australia,’ vol. i. pp. 300, 308, the ‘ Student,’ April, 1870, p. 125. 448, 451. On the ptarmigan, above Gould, ‘ Handbook to the Birds alluded to, see Lloyd, ibid. p. 120. (JnAP, XIV. Unpaired Birds. 407 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 special names. Unpaired Birds. — 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 conspic- uous 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 succeed- ing 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.® 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 game- keepers in Delamere Forest assured Mr. Fox that the magpies and carrion-crows 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 killed. Sir J. Lubbock’s gamekeeper has repeatedly shot, but how often he could not say, one of a pair of /\ys (^Oarrulus glandarius'), * On magpies, Jenner, in ‘ Phil. p. 570. Thompson, in ‘ Annals and Transact.’ 1824, p. 21. Macgil- Mag. of Nat. Hist.’ vol. viii. 1842, livvay, ‘ Hist. British Birds,’ vol. i. p. 494. 4o8 Paki II. The Descent of Man. and has never failed shortly afterwards to find the survivor re-matched, Mr. Fox, Mr. F. Bond, and others have shot one of a pair of carrion-crows (^Corvus corone), but the nest was soon again tenanted by a pair. These birds are rather common; but the peregrine-falcon (^Falco peregrinux) is rare, yet Mr. Thompson states that in Ireland “ if either an old male or female be killed “ in the breeding- season (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 yoimg.” Mr. Jermer Weir has known the same thing with the peregrine-falcons at Beachy Head, The same observer informs mo that three kestrels ( h'alco tiniumcnlus), 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 mischief went on.” White of Selbome, 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 house-martins 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 {Fhaintciira ruti- cilla), 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. Mi*. 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 call-note is not loud. I will give only one other fact, on the authority of this same observer ; one of a pair of starlings (Stumus vulgaris) was shot in the morning; by noon a new mate was found ; this was again shot, but befdro 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 Oha?. Xl^ Unpaired Birds. 409 season he kept an account, and found that he had shot thirty-five 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.® 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, carrion-crows, 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, carrion-crows, 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 rmion 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 love-song long after the proper time, shew- ing that they have either lost or never gained a mate. Death from accident or disease of one of a pair, would leavn the other free and single ; and there is reason to believe that female birds during the breeding-season are especially liable to premature death. Again, bii'ds 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.’' Such contingencies as these probably explain most of the foregoing cases.® Nevertheless, it is a strange ® 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 Phocni- cura, 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. ' See White (‘ Nat. Hist, of Sel- borne,’ 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 in- stances See Jenner, on the retarded state of the generative organs in certain birJs, 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 carrion-crows, see the ‘ Field,’ 1868, p. 415. On various male birds singing after the proper period, see Kev. L. Jenyns, ‘Observations in Natural History,’ 1846, p. 87. * The following case has been given (‘ The Times,’ Aug. 6th, ISoS) by the Rev. F. 0. Morns, on the authority of the Hon. and Rev. 0. 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 winss clipped at “ a decoy to destroy the old ones by. 410 The Descent of Man. Pabt 1L fact that within the same district, during the height of the breeding-season, 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 Wem, 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 sncceed 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 occasionally evince towards particular males. Mental Qualities of Birds, and their Taste for the Beautiful. — 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. 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 tliese 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 theii- 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 fkcts proving the attachment of mated birds.‘“ “ 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 chari- table hawks, who had come with “ an adopted feeling to succour the orphan. The.se 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.” • I am indebted to Prof. Newton for the following passage from Mr. Adam’s ‘ Travels of a Naturalist,’ 1870, p. 278. Speaking of Japanese nut-hatches 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 1 substituted hard hazel- “ nuts. As the bird was unable “ to crack them, he placed them one “ by one in his water-glass, evideatly “ with the notion that they would “ in time become softer — an interest- “ ing proof of intelligence on the “ part of these birds.” ‘A Tour in Sutherlandshire,’ vol. i. 1849, p. 185. Dr. Bnller says (‘Birds of New Zeal.and,’ 1872, p. 56) that a male King Lory was killed; and the fem.ale “fretted and Chap. XIV. Mental Qualities. 411 ill-. Bennett relates” that in China after a drake of the beantiful mandarin Teal had been stolen, the duck remained disconsolate, though sedulously courted by another mandarin drake, who dis- played before her all his chai-ms. 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 two, when brought together again, rarely, if ever, recognise each other. 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 frost-bitten 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.” “ They have good memories, for in the Zoological Gardens they have plainly recognised their former masters after an interval of some months. Birds possess acute powers of observation. Every mated bird, of cotuse, 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 “ tuoped, refused her food, and died ** ‘ Acclimatization of Parrots,’ “of a broken heart.” by C. Buxton, M.P. ‘Annals and '* ‘Wanderings in Kew South Mag. of Nat. Hist.’ Nov. 1868, t>. Wales,’ vol. ii. 1834, p. 62. 38I. 412 The Descent of Man. Paut II. have heard of mimerous 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.” “ 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 he 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.^ Mr. Jenner Weir is convinced that birds pay particular atten- tion to the colours of other birds, sometimes out of jealousy, and sometimes as a sign of kinship. Thus he turned a reed-bunting (Jimbtriza sckomiculus), which had acquh’ed its black head-di’ess, into his aviary, and the new-comer 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 reed-bunting, which had not as yet become black-headed : but the reed-bunting with a black head was so unmercifully treated, that it had to be removed. Spiza cyanea, during the breeding-season, is of a bright blue colour ; and though generally peaceable, it attacked S. ciris, which has only the head blue, and completely scalped tlie 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 hand, he has observed that some birds, when first intro- duced, fly towards the species which resemble them most in colour, and settle by their sides. As male buds display their fine plumage and other ornaments ” ‘Tlie Zoologist,’ 1847-1848, p. p. 39. Audubon on the wild turkey, 1602. ‘Ornith. Biogi-ophy,’ toI. i. p. 14. Hewitt on wild ducts, ‘Journ.ll On the mocking-thrush, ibid. voL L of Horticulture,’ Jan. 13, 1863, p. 110. Chap. XIV. Taste for the BeautiftiL 413 with so much care before the females, it is obyiously 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 looking-glass (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 per- haps the former feeling "which, as stated by Lord Lilford,'® attracts the ruff towards any bright object, so that, in the Ionian Islands, “ it ■wiU 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 ghtter 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 silver articles or jewels ? Mr. Gould states that certain humming-birds decorate the outsides of their nests “ •with the utmost taste ; they instinctively “ fasten thereon beautifid 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 bower-birds already mentioned. Their bowers (see fig. 46, p. 382), 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 bower-bird collects gail.\ -coloured articles, such as the blue tail-feathers of parrakeets, bleached bones and shells, which it sticks between the twigs, or arranges at the entrance. Mr. Gould found in one bower a neatly-worked stone tomahawk and a slip of blue cotton, evidently procured from a native encampment. These objects are continually re-arranged, and carried about by the birds whilst at play. The bower of the Spotted bower-bird “ is beautifully lined with tall grasses, so disposed that the heads nearly meet, and the decorations are very profuse. ’ Hound stones are used to keep the grass-stems in their proper places, and to make divergent paths leading to the bo-wer. The stones and shells are often brought from a great distance. The Eegent bird, as described by Mr. Ramsay, ornaments its short bower with bleached land-shells 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.' The < Ibis,’ vol. ii. 1860, p. 344. 414 The Descent of Man. Paet II. “ Besides these there were several newly-picked leaves and “ young shoots of a pinkish colour, the whole shewing a de- “ cided 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 dis- " covered and the taste, as we see, of the several species • certainly differs.’® Preference for particular Males by the Females. — 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 MacgiUivTay relates how a male blackbird and female thrush “fell in love with each other,” and produced offspring.” Several years ago eighteen cases had been recorded of the occurrence in Great Britain of hybrids between the black grouse and pheasant ; ** but most of these cases may perhaps be accormted 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’® states that out of a flock of twenty-three Canada geese, a female paired with a solitary Bemicle gander, although so different in appearance and size; and they produced hybrid ofifepring. A male widgeon {Mareca penelope), living with females of the same species, has been known to pair with a pintail duck, Querguedida acuta. Lloyd describes the remarkable attachment between a shield- drake (fladorna vulpanser') and a common duck. Many ad- On the ornamented nests of humming-birds, Gould, ‘ Introduc- tion to the Trochilida,’ 1861, p. 19. On the bower-birds, Gould, ‘ Hand- book to the Birds of Australia,’ 1865, vol. i. pp. 444-461. Rams.ay, in the ‘ Ibis,’ 1867, p. 456. ” ‘ Hist, of British Birds,’ vol. ii. p. 92. ** ‘Zoologist,’ 1853-1854, p. 3946. Waterton, ‘Essays on Nat. Hist.’ 2nd series, pp. 42 and 117. For the following statements, see on the widgeon, Loudon’s ‘ Mag. of Nat. Hist.' vol. ii. p. 616; L. Lloyd, ‘Scan- dinavian Adventures,’ vol. i. 1854, p. 452. Dixon, ‘ Ornamental and Domestic Poultry,’ p. 137 ; Hewitt, in ‘Journal of Horticulture,’ Jan. 13, 1863, p. 40; Bechstein, ‘Stu- benvogel,’ 1840, s. 230. Mr. J. Jenner Weir has lately given me an analogous case with ducks of two species. Chap. XIV. Preferejice by the Female. 415 ditional instances could be given; and the Eev. E. S. Dixon remar lis 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. Pox 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 new-comer 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 caimot 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 Pechstein, 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 s('me The Descent of Man. Part It 416 of tho hybrid unions above naentioned ; but in many of those cases the birds were allowed to range freely over large ponds, and there is no reason to suppose that they were unnaturally stimulated by high feeding. With respect to birds in a state of nature, the first and most obvious supposition which will occur to every one is that tho 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. Audubon— and 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 deUberately chooses her mate ; thus, speaking of a woodpecker, he says the hen is followed by half-a-dozen gay suitors, who continue performing strange antics, “ until a marked preference is shewn for one.'’ The female of the red-winged starling {Agehdus phceniceus) 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 night-jars repeatedly plunge tlirough 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 {Calhartes 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 hkewise carefully observed the wild flocks of Canada geese {Anser canadensis), and gives a graphic description of their love-antics; 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, imtil all seemed satisfied with “ the choice they had made, after which, although they re- “ mained together, any person could easily perceive that they “ were careful to keep in pahs. I have observed also that the “ older the birds, the shorter were the preliminaries of theh “ 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.’’*'’ Many similar statements with respect to other bhds could be cited from this same observer. Turning now to domesticated and confined bhds, I will commence by giving what little I have learnt respecting the " Audubon ‘ Ornitholog. Biography, vol.i. pp. 191,349; vol. ii. pp. 42, 275 ; vol. iii. p. 2. Chap. XIV. Preference by the Female. 417 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 arti- ficial state under which these birds have long been kept. Mr. Tegetmeier is convinced that a game-cock, 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 roosting-place will resort to the “ game-cock, even though that bird may not actually drive “ away the male of her own variety.” Under ordinary circum- stances the males and females of the fowl seem to come to a mutual rmderstanding 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. Herguson, however, describes how a quarrelsome hen was subdued by the gentle courtship of a Shanghai cock.^* There is reason to believe that pigeons of both sexes prefer pairing with birds of the same breed; and dovecot-pigeons dislike aU the highly improved breeds.^^ 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 ‘ Rare and Prize Poulti-y,’ 1854, Plants under Domestication,’ vol. ii p. 27. p. 103. ” ‘ The Variation of Animals and 2 E Past II. 418 T he Descent of Mmi. 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. Teget- meier, at my request, stained some of his birds with magenta, but they were not much noticed by the others. Female pigeons occasionally feel a strong antipathy towards certain males, without any assignable cause. Thus MM. Boitard and Corbie, whose experience extended over forty-five yeai's, state : “ Quand une femeUe 4prouve de I’antipathie pour un “ male avec lequel on vent I’accoupler, malgre tons les feux “ de I’amour, malgre I’alpiste et le cheuevis 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 empressdes, les agaceries, les toumoie- “ mens, les tendres roucoulemens, rien ne pent lui plaire ni “ I’emouvoir ; gonflee, boudeuse, blottie dans un coin de sa “ prison, elle n’en sort que pour boire et manger, ou pour re- “ pousser avec une espece de rage des caresses devenues trop pres- sautes.”^® 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, accord- ing to another experienced observer, Eiedel,^* 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 be shut up on account of the mischief which they cause. 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.“ Here is a more curious case. Sir E. 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 peacock. 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 trelUce-walls of his prison, and would not suffer a japanned Boitard and Corbid, ‘Les ** ‘Die Taubenzucht,’ 1824, s. 86. Pigeons, &c.,’ 1824, p. 12. Prosper “ ‘OrnPhological Biography,’ Lucas (‘Traits de PH^rdd. Nat.’ vol. i. p. 13. See to the same effect, tom. ii. 1850, p. 296) has himself Dr. Bryant, in ‘ Allen’s Mammals and observed nearly similar facts with Birds of Florida,’ p. 344. pigeons. Chap. XIV. Preference by the Female. 419 " peacock to touch them. On his being let out in the autumn, " the oldest of the hens instantly couiiud him, and was success- “ ful in her courtship. The next year he was shut up in a stable, " and then the hens all com-ted his rival.” This rival was a japanned or black- winged peacock, to our eyes a more beautiful bird than the common kind. Lichtenstein, who was a good observer and had excellent opportunities of observation at the Cape of Good Hope, assured Eudolphi that the female widow-bh'd ( Cliera ‘progne) disowns the male, when robbed of the long tail-feathers with which he is ornamented during the breeding-season. I presume that this observation must have been made on birds under confinement.^^ Here is an analogous case ; Dr. Jaeger director of the Zoological Gardens, of Vienna, states that a male silver-pheasant, 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 the flock. It is a remarkable fact, as shewing how important colour is in the courtship of bu’ds, that Mr. Boardman, a well-known col- lector 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 sj)ecies.^® 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 them rejection by their normally coloured comrades. Female birds not only exert a choice, but in some few cases they court the male, or even fight together for his possession. Sir E. 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 Ms attention.®" We have seen that a tame wild-duck Proc. Zool. Soc.’ 1835, p. 54. The japanned peacock is considered by Mr. Sclater as a distinct species, and has been named Pavo nigri- pennis-, but the evidence seems to me to shew that it is only a variety. Eudolphi, ‘Beytrage zur An- thropologie,’ 1812, s. 184. ’3 ‘ Die Darwin’sche Theorie, uud ihre Stellung zu Moral und Re- ligion,’ 1869, s. 59. This statement is given by Mi A. Leith Adams, in his ‘ Field and Forest Rambles,’ 1873, p. 76, and accords with his own experience In regard to peafowl, see Sir R, Heron, ‘Proc. Zoolog. Soc.’ 1835, p. 54, and the Rev. K. S. Dixon, 2 E 2 420 The Desce^it of Man. Paht II. seduced an unwilling pintail drake after a long courtship. Mr. Bartlett believes that the Lophophorus, like many other gallinar ceous 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. .Tenner Weir introduced a dull-coloured 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 re- tribution, for, ceasing to be pugnacious, she was replaced by the old female, and the male then deserted his new and returned to his old love. 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 Idgh 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 from some inexpKcable 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 Long-tailed duck (Hardda 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.®* With respect to female birds feeling a preference for particular Ornamental Poultry,’ 1848, p. 8. For the turkey, Audubon, ibid. p. 4. For the capercailzie, Lloyd, ‘ Game Bird of Sweden,’ 1867, p. 23. Mr. Hewitt, quoted in ‘Tcgot- meier’s Poultry Book,’ 1866, p. 165. Quoted in Lloyd’s ‘ Game Birds of Sweden,’ p. 345. Chap. XIV. Preference by the Female. 421 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 breeding-season. They sedulously display their various ornaments, exert their voices, and perform strange antics in the presence of the females. Even well-armed 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 pro- longed affair. There is even reason to suspect that the males and females within the same district do not always succeed in pleasing each other and pairing. What then are we to conclude from these facts and considera- tions ? Does the male parade his charms with so much pomp and rivahy for no pm-pose ? 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 tram of the peacock — she is probably struck only by the general effect. Nevertheless, after hearing how carefuUy the male Argus pheasant displays his elegant primary wing-feathers, and erects his ocellated plumes in the right position for their lull effect; or again, how the male goldfinch alternately displays his gold-bespangled 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 422 The Descent of Man. I’AUT II. 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 existence of the species. Variability of Birds, and especially of their Secondary Sexual Characters. — Variabihty 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 bf nature have been modified into distinct races is now universally admitted.®® Variations may be divided into two classes ; those which appear to our ignorance to arise spon- taneously, 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,®* who shews 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 Euro- pean birds. It is also an unsettled point with naturalists, whether several North American birds ought to be ranked ns specifically distinct from the corresponding European species. So again many North Ame- rican forms which until lately were named as distinct species, are now considered to be local races. ‘Mammals and Birds of East Florida,’ also an ‘ Ornithological Re- connaissance of Kansas, &c. Not- withstanding the influence of cli- mate 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 ap- pears, Egypt (see Mr. Hartshorne in the ‘American Naturalist,’ 1873, p. 747). These countries are open, and afford little shelter to birds y 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. 1 have sometimes speculated whether the prevailing dull tints of the scenery in the above named countries may not have affected the apprecia- tion of bright colours by the birr.s inhabiting them. Ohap. xiy. Variability. 423 that in the United States many species of birds gi-adnally 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 varia- tions 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.** 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*® that near- Bogota certain humming-birds 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 grass- “ green.” In another parrakeet of the same country “ some “ individuals have the band across the wing-coverts bright- ‘Origin of Species,’ fifth edit. 1869, p. 104. I had always per- ceived, that rare and strongly- marked deviations of structure, de- serving to be called monstrosities, could seldom be preserved through natural selection, and that the pre- servation of even highly-beneficial 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 insi.st so strongly on the im- portance of that unconscious form of selection by man, which follows from the pre.servation of th’, 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 Re- view ’ (March 1 867, p. 289, et seq.), which has been of more use to me than any other Review, I did not see how great the chances weir against the preservation of varia- tions, whether slight or strongly pronounced, occurring only in single individuals. “o ‘ Introduct. to the Trochilida*, p. 102. 424 The Descejit of Man. Part II. “ yellow, while in others the same part is tinged with red.” 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 ; ” but this variation seems to be somewhat rare, so that its preservation through sexual selection would follow only under imusually favourable circum- stances. 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 well- “ marked occipital crest formed of several graduated feathers.” 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 Briinnich to conclude that they were specifically distinct; but this is now known to be an error.^° This case seems analogous to that lately given of albino birds not pairing from being rejected by their comrades. 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 by a pure white ring roimd the eye, with a curved narrow white line, an inch and a half in length, extending back from the ring. This conspicuous cha- racter has caused the bird to be ranked by several ornithologists as a distinct species under the name of U. lacrymam, but it is now known to be merely a variety. It often pans 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,'*^ transmitted either unaltered or not at aU. We thus see that two distinct forms of the same species may co-exist in the same district, and we cannot doubt Gould, ‘ Handbook to Birds of Fiiro,’ 1830, s. 51-54. Macgillivray, Australia,’ vol. ii. pp. 32 and 68. ‘ Hist. British Birds,’ vol. iii. p. Audubon, ‘ Ornitholog. Bio- 745. ‘ Ibis,’ vol. v. 1863, p. 469. graphy,’ 1838, vol. iv. p. 389. ■" Graba, ibid. s. 54. Macgil- »" Jerdon, ‘ Birds of India,’ vol. i. livvay, ibid. vol. v. p. 327. p. 108; and Mr. Blyth, in ‘Land ‘Variation of Anim.ils and and Water,’ 1868, p. 381. Plants under Domestication,’ vol. ii. « Graba, ‘ Tagobuch Reise nach p. 92. Chap. XIV. Variability. 425 that if the one had possessed any advantage over the other, it •woiild 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 (hke 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.'*® There is also reason to beheve, 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 follo'wing 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 sexually-limited 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 shght 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 ?*■* 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 gamboge-yellow; with many hombills (Buceros), as I hear from Mr. Blyth,^® the males have intense crimson eyes, and those of the females are white. In the Buceros licornis, 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 thi’ough sexual selection in the males ? This is very doubtful ; On these points see also ‘ Varia- of a Podica and Gallicrex in ‘ Ibis,’ tion of Animals and Plants under vol. ii. 1860, p. 206; and vol. v. Domestication,’ vol. i. p. 253 ; vol. ii. 1863, p. 426. '*** See also Jerdon, ‘ Birds of See, for instance, on the irides India,’ vol. i. pp. 243-245. 426 The Descent of Man. Part II. for Mr. Bartlett shewed me in the Zoological Gardens that the inside of the mouth of this Buceros is black in the male and flesh-coloured in the female; and their external appearance or beauty would not be thus affected. I observed in Chili " that the iris in the condor, when about a year old, is dark-brown, but changes at maturity into yellowish-brown in the male, and into bright red in the female. The male has also a small, longitu- dinal, leaden-coloured, 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-colom-ed 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 deformities — deep 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 open — are all admired as ornamental. 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 top-knot, which is a new character in the genus, the feathers on the head of the male become hackle-shaped, 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 top-knot 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 Silver-spangled Polish, the Houdans, and Creve-coeur 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 Amherst pheasants. The structure of each individual feather generally causes any ‘Zoology of the Voynge of II.M.S. Beagle,’ 1841, p. 6. Chap. XIV. Ocelli. 427 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 game-hen, all the feathers were greenish-black, excepting towards their extremities, which were yellowish-white; but between the white extremities and the black bases, there was on each feather a symmetrical, curved zone of dark-brown. In some instances the shaft of the feather determines the distribution of the tints; thus with the body- feathers of a mongrel from the same black Spanish cock and a silver-spangled Polish hen, the shaft, together with a narrow space on each side, was greenish-black, and this was surrounded by a regular zone of dark-brown, edged with brownish-white. 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 wing-bars symmetrically zoned with three bright shades, instead of being simply black on a slaty-blue ground, as in the parent-species. In many groups of birds the plumage is ditterently 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 wing-bars, though they may be colom’ed 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 sub-variety having a white instead of a blue tail, with precisely that part black which is white in the parent-species.'''^ Formation and Variability of the Ocelli or eye-like Spots on the riurnage of Birds. — As no ornaments are more beautiful than the ocelli on the feathers of various birds, on the hairy coats of some mamrnals, 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 " Bechstein, ‘ Naturgeschichte Deutschlands,’ B. iv. 1795, s. 31, on s fub-variety of the Monck pigeon. 428 Paet 1L The Descent of Man. iris, but the central spot is often surrounded by additional con- centric zones. The ocelli on the tail-coverts of the peacock offer a famihar example, as well as those on the wings of the peacock- butterfly (Vanessa). Mr. Trimen has given me a description of a S. African moth (Gyananis tsis), 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 semi-transparent crescent-shaped mark, surrounded by successive, ochre-yellow, black, ochre-yellow, 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 mar^g 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 meadow-brown butterfly (Hipparchia janira) exhibiting numerous gi-adations from a simple minute black spot to an elegantly-shaded 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 (A'), 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 (B^).'*® In cases hke these, the development of a perfect ocellus does not require a long course of variation and selection. With birds and many other animals, it seems to foUow 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 ; and something of the same Mnd 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 ■** This woodcut has been en- wings of this butterfly, in his graved from a beautiful drawing, ‘Ehopalocera Africa! Australis,’ p. most kindly made for me by Mr. 186. Trimen ; see also his description of Jerdon, ‘ Birds of India,’ vol. the wonderful amount of variation iii. p. 517. in the coloration and shape of the Chap. XIV, Ocelli. 429 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 surround- ing 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 Fig. 63. Cyllo leda, Linn., from a drawing by Mr. Triraen, shewing the extreme range of variation in the ocelli. A. Specimen, from Mauritius, upper B. Specimen, from Java, upper surface of the common guinea-fowl offer a good instance of white spots surrounded by darker zones ; and wherever the white spots are large and stand near each other, the suiTounding dark zones become confluent. In the same wing-feather 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 sur- rounded 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 ocelh on many Lepidoptera, lead us to conclude that their formation is not a complex process, but depends on some slight and graduated change in the nature of the adjoining tissues. A surface of fore-wing. Ai. Specimen, from Natal, ditto. of hind-wing. BL Specimen, from Mauritius, ditto. 430 Part II. The Desce7it of Mari. Gradation of Secondary Sexual Characters.— Ga&os of gradation ai'e 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 has become so splendidly decorated. The peacock is chiefly remarkable from the extraordinary length of his tail-coverts ; the tail itself not being much elongate. 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, in- tensely blue, indented centre, surrounded by a rich green zone, this by a broad coppery-brown 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 else- where described an exactly analogous variation in the hackles of a sub-variety 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 dark-blue 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 ate common to the Indian and Javan peacocks {Pavo cristatus and P. muticus) ; and they seemed to deserve particular attention, as probably connectetl with the development of the ocellus ; but for a long time I could not conjecture then- meaning. “ ‘ Variation of Animals and Plants under Domestication,’ vol. i. p. 254 Chap. XIY. Gradation of Characters. 431 If we admit the principle of gradual evolution, there must formerly have existed many species which presented every suc- cessive step between the wonderfully elongated tail-coverts 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 aU the other characters of the peacock. Let us look to the allied Gallinacese for any stiU-existing gradations. The species and Ilg. 64. Feather of Peacock, about two-thirds of natural size, drawn by Mr. Ford, The transparent zone is represented by the outermost white zone, confined to the ripper end of the disc. 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 peacock-pheasants. I am also in- formed 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 plain-coloured females, expanding and erecting their tail and 432 The Descent of Man. Past IL wing-feathers, which are ornamented with nnmerous ocelli. I request the reader to turn hack to the drawing (fig. 51, p. 397) of a Polyplectron. In P. napoleonis the ocelli are confined to the tail and the back is of a rich metallic blue ; in which re- spects this species approaches the lava peacock. P. hwrdvnckii possesses a peculiar top-knot, 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, greenish-blue or greenish-purple 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 tail-coverts is another remarkable character in Polyplectron ; for in some of the species they are half, and in others two-thirds as long as the true tail-feathers. The tail- coverts are oceUated as in the peacock. Thus the several species of Polyplectron manifestly make a graduated approach to the peacock in the length of their tail-coverts, m the zoning of the ocelli, and in some other characters. Notwithstanding this approach, the first species of Polyplectron which I examined ahnost made me give up the search; for I found not only that the true tail-feathers, which in the peacock are quite plain, were ornamented with ocelh, 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 pro- genitors 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 tail-feathers of P. hardwickii they touched each other; and. finally, that on the tail-coverts of tMs same species as well as of P. malaccmse (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 hkewise indented. A single ocellus is thus formed on each tail- covert, though still plainly betraying its double origin. These confluent ocelli differ from the single ocelh 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 speciQS (as in P. chinquis) they converge towards one end ; now the partial confluence of two convergent ocelh would manifestly leave a much deeper indentation at the divergent tlian at the coiivergent end. It is also manifest that if the convergence were Chap. XIV. Birds — Gradation of Characters. 433 strongly pronounced and the confluence complete, the indentation at the convergent end would tend to disappear. The tail-feathers in both species of peacock are entirely destitute of ocelli, and this apparently is related to their being covered up and concealed by the long tail- coverts. In this respect they differ remarkably from the tail- feathers of Polyplectron, which in most of the species are or- namented with larger ocelli than those on the tail-coverts. Hence I was led carefully to examine the tail-feathers of the several species, in order to discover whether their ocelli shewed any tendency to dis- appear; and to my great satis- faction, this appeared to be so. The central tail-feathers 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 -tail-feathers, until a mere shadow or rudiment is left on the inner side of the outermost feather. Again, in P. malaccense, the ocelli on the tail- coverts are, as we have seen, confluent ; and these feathers are of unusual length, being two- thirds of the length of the tail- feathers, so that in both these re.spects they approach the tail- •roverts of the peacock. Now in P . malaccense the two central tail- feathers alone are ornamented, each with two brightly-coloured ocelli, the inner ocellus having completely disappeared from all the other tail-feathers. Conse- quently the tail-coverts and tail-feathers of this species of Poly- plectron make a near approach in structure and ornamentation to the corresponding feathers of the peacock. Fig. 65. Part of a tail-covert of Poly- plectron chinquiB, with the two ocelli of nat. size. Fig 56. Part of a tail-covcrt of Poly- plectron malaccense, with the two ocelli, partially confluent, of nat. size. 2 F 4.H Tlie Descent of Man. ABT II. As far, then, as gradation throws light on the steps by which the magnificent train of the peacock has been acquired, hardlj anything more is needed. If we picture to ourselves a progeni- tor of the peacock in an almost exactly intermediate condition between the existing peacock, with his enormously elongated tail-coverts, ornamented with single ocelli, and an ordinary gallinaceous bird with short tail-coverts, merely spotted with some colour, we shall see a bird allied to Polyplectron — that is, with tail-coverts, capable of erection and expansiou, ornamented with two partially confiuent 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 jwacock, speaks plainly in favour of this view, and is otherwise in- explicable. 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 of the most beautiful males, rendered the peacock the most splendid of Living birds. Argus pheasant. — Another excellent case for investigation is ofiered by the ocelli on the wing-feathers of the Argus pheasant, which are shaded in so wonderful a manner as to resemble balls lying loose within sockets, and consequently difier from ordinary ocelli. No one, I presume, will attribute the shading, which has excited the admii’ation of many experienced artists, to chance — to 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 ball-and-socket effect, seems as incre^ble, as that one of Eaphael’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 ot progenitors, nor to many closely-allied 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 de- monstration th.at a gradation is at least possible from a mere spot to a finished ball-and-socket ocellus. The wing- feathers, bearing the ocelli, are covered with dark stripes (fig. 57) or with rows of dark spots (fig. 59), each stri]'e or row of spots running obliquely down the outer side of the Chap. XIV. Birds — Gradation of Characters. 43? 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 row — and then they form a longitudinal stripe — or transversely, that is, with the spots in the adjoining rows, and then they arc form transverse stripes. A spot sometimes breaks up into smaller spots, which still stand in their proper places. It will be convenient first to describe a per- fect ball - and - socket ocellus. This consists of an intensely black circular ring, surround- ing a space shaded so as exactly to resemble a ball. The figure here given has been ad- mirably 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 (see 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 to- wards the base on the right hand. These little breaks have an important meaning. 'Ihe ring is always much thickened, with the edges ill-defined towards the h ft- hand upper corner, the feather being held erect, in the posi- tion in which it is here drawn. Beneath this thickened pnrt there is on the surface of the ball an oblique almost pure-white mark, which shades olf downwards into a pale-lcaden hue, and this into yellowish and brown tints, which insensibly become Fig. 57. Part of secondary wing-feather of Argus pheasant, shewing two perfect ocelli, a and b. A, B, C, D, Ac., are dark stripes running obliqi ely down, each to an ocellus. [Much of the web on both sides, especially to the left of the shafts has been cut off.] 2 F 2 436 The Descent of Man. Pabt II. 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 sepa- rated 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 bail. 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 wood- cut ; D to the next lower one, and CO with the stripes B and F. Lastly, the several ocelh are separated from each other by a pale smTace bear- ing irregular black marks. I will next describe the other extreme of the series, namely, the first trace of an ocellus. The short se- condary wing - feather (fig. 58), nearest to the body, is marked like the other feathers, with oblique, lon- gitudinal, rather irregular, rows of very dark spots. The basal spot, or that near- est 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 elon- gated in a transverse direc- tion. 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 tho upper ones in Fig. 58. Basal part of the secondary-wing feather, nearest to the body. Chap. XIV. Birds — Gradation of Characters. 437 the same row. The larger basal spots occupy exactly the same relative position on these feathers, as do the perfect ocelli on the longer wing-feathers. By looking to the next two or three succeeding wing-feathers, an absolutely insensible gradation can be traced from one of the last-described 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, 0, D, A B c Fig. 59. Portion of one of the secondary wing-feathers near to the body, shewing the so-called elliptic ornaments. The right-hand figure is given merely as a diagram for the sake of the letters of reference. A, H, C, D, &c. Eows of spots running c. The next succeeding spot or mark in down to and forming the elliptic the same row. ornaments. d. Apparently a broken prolongation of 6. Lowest spot or mark in row B. the spot c in the same row B. &c. (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 ball-and-socket 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 438 The Descent of Man Part 1L 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 (6) 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 (6 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 (6). 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 sub-triangular 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- 1 do not feel sure of this. These three marks, 6, c, and d, with the intervening bright shades, form together the so-called elliptic ornament. These ornaments placed parallel to the shaft, manifestly correspond in position with the ball-and-socket ocelli. Their extremely elegant appearance can- not be appreciated in the drawing, as the orange and leaden tints, contrasting so well -with the black marks, cannot be she-wn. Between one of the eUiptic ornaments and a perfect ball-and- socket 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 (6 fig. 59), and more especially of the upper one (c), together -with the conti’action of the elongated sub-triangular or narrow mark (d), so that at last these three marks become con- fluent, 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 dra-wing (flg. 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 (6 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 ball-and-socket ocellus. Even Ch.**f. XIV. Birds- — Gradation of Characters. 439 in the most perfect ocelli, ti-acesof the junction of three or four eloncrated black marks, by wliich the ring has been formed, may often be detected. The ii-regular sub-triangular or narrow mam {d fig. 59), manifestly forms, by its contraction and equalisation, the thickened portion of the ling above the white shade on a perfect ball- and-socket ocellus. The lower part of the ring is invariably a little thicker than the other parts (see fig. 57), and this follows from the lower black mark of the elliptic ornament (6 fig. 59) having origi- nally been thicker than tbe upper mark (c). Every step can be fol- lowed 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, 5, c, d, of the eUiptic ornament. The irre- gular zigzag black marks between the successive ocelli (see again fig. 57) are plainly due to the breaking up of the somewhat more regular but similar marks between the elliptic ornaments. The successive steps in the shading of the ball-and-socket ocelli can be followed out with equal clearness. The brown, orange, and pale leaden 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 left-hand corner ren- dered still fighter, so as to become almost white, and at the same time more contracted. But even in the most perfect ball-and- socket 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 fine 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 ball-and-socket 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 sim])le spots, the lower one (fig. 58) having some dull fulvous shading on its upper side. Fig. 60. An ocellus in an inter- mediate condition between tbe elliptic ornament and the perfect ball-and-socket oceUus. 440 Pabt IL The Descent of Man. The extremities of the longer secondary feathers which bear the perfect ball-and-socket ocelli, are peculiarly ornamented (fig. 61). The oblique longitudinal stripes suddenly cease upwards and become confused ; and above tliis limit the whole upper end of the feather (a) ia covered with white dots, sur- rounded by httle black rings, standing on a dark ground. The oblique stripe belonging to the uppermost ocellus (6) is barely represented by a very short iiTogular black mark v ith the usual, curved, tranverse base. As this stripe is thus abruptly cut off, we can perhaps under- stand 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 prolonga- tion 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 beheves 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 wing- feather 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 run down to the Fig. 61. Portion near summit of one of the secondary wing-feathers, bearing perfect ball-and-socket oceUi. o. Ornamented upper part. 6. U ppennost, imperfect ball-and-socket ocellus. (The shading above the white mark on the summit of the ocellus is here a little too dark.) c. Perfect ocellus. same ocellus. Chap. XI Y. Birds — Gradation of Characters 441 There still remains another very curious point, first observed by Mr. T. W. Wood,®* 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 like- wise 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. Never- theless 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 suffi- ciently lateral. We have, however, no right to expect absolute perfection in a part rendered ornamental through sexual selec- tion, 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.®^ We have now seen that a perfect series can be followed, from simple spots to the wonderful ball-and-socket ornaments. Mr. Gould, who kindly gave me some of these feathei-s, 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 betore 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 The ‘ Field,’ May 28, 1870. Subjects,’ Eng. trans. 1873, pp 210 Popular Lecture# on Scientific 227, 269, 390. ’ 442 T)ie Descetit of Man. Part IT. 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 ball-and- socket 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 ball-and-socket ocelli were finally developed. Thus we can understand— and in no other way as it seems to me — the present condition and origin of the orna- ments on the wing-feathers of the Argus pheasant. From the light afforded by the principle of gradation — from what we know of the laws of variation — from the changes which have taken place in many of our domesticated birds — and, lastly, from the character (as we shall hereafter see more clearly) of the immature plumage of young birds— we can sometimes indicate with a certain amount of confidence, the probable steps by which the males have acquired their brilliant plumage and vai'ious ornaments ; yet in many cases we are involved in complete darkness. Mr. Gould several years ago pointed out to me a humming-bird, the Urosticte henjamini, remarkable for the ciu'ious differences between the sexes. The male, besides a splendid gorget, has greenish-black tail-feathers, with the four central ones tipped with white ; in the female, as with most of the alhed species, the three outer tail-feathers 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 humming-birds, Mr. Gould does not know a single species, be- sides the Urosticte, in which the male has the four central feathers tipped with white. The Duke of Argyll, in commenting on this case,®* 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. Hut can this be so confidently said of sexual selection ? Seeing in how many ways the tail-feathers of humming-bu-ds differ, why should not the four central feathers have varied in this one species alone, so as to have acquired white tips ? The varirtions may have been gradual, or somewhat abrupt as in the case •3 ‘ The Reign of Law,’ 1867, p. 247. Chap. XIV. Birds — Gradation of Characters. 443 recently given of the hnmming-birds near Bogota, in which certain individuals alone have the “ central tail-feathers 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 ear-tufts, 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 snow-white male of the Bell-bird. The statement made by Sir E. 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 tail-feathers 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 humming- birds take especial pains in displaying their tail-feathers ; Mr. Belt,"* after describing the beauty of the Florisuga melUvora, says, “ I have seen the female sitting on a branch, and two males “ displaying their charms in front of her. One would shoot up “ hke a rocket, then suddenly expanding the snow-white 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 featui’e 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.” If this bo admitted, wo 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 have left a larger number of offspring to inherit their newly-acquired beauty. ‘ The Katuralist in Nicaragua,’ ‘ Introduction to the Trochi- 1874, p. 112 lid< 1861, p. 110. 444 The Descejit of Man. Part IL CHAPTER XV. BIBDS — continued. Discussion as to why the males alone of some species, and both seies of others, are brightly coloured — On sexually-limited inheritance, as applied to various structures and to brightly-ooloured plumage — Nidification in relation to colour — Loss 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 conspicuously coloured than the male. In my ‘Origin of Species’^ 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 natui’al 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,^ 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 colom’s of the male, owing to the danger which she would thus have incurred dui-ing incubation. 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 ‘ Fourth edition, 1866, p. 241. 1867. ‘Journal of Travel,’ rol. L * ‘Westminster Review,’ July, 1868, p. 73. Chap. XV. Birds — Sexually Limited Inheritance. 445 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 trans- mitted to both sexes equally, the fancier would have to try to convert this latter form of inheritance into sexually-limited transmission. All that he could do would be to persevere in selectmg every male pigeon which was in the least degree of a paler blue; and the natural result of this process, if steadily can-ied 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 com- pelled 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 pale-blue tint ; for the primordial slaty colour would be transmitted with prepotent force. Supposing, however, that some pale-blue 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, &c., 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 pale-blueness, that they would not destroy this coloiu* in their noale 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 colour might be gained. The extreme importance, or rather necessity in the above case of the desired character, namely, pale-blueness, 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 thirty-seven 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 Scemmerring pheasant with her &liort 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 Scemmerring pheasant, were crossed with the male Tke Descent of Mayi. Part IL 446 of the latter, the male hybrid offspring would have a much shorter tail than that of the pure offspring of Scemmerring’a pheasant.’ Our fancier, in order to make his new breed with the males of a pale-blue tint, and the females unchanged, would have to continue selecting the males during many generations; and each stage of paleness would have to bo fixed in the males, and rendered latent in the females. The ta.sk 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 pale-blue tint, from the necessity of reiterated crosses with the slaty female, the latter not having at first any latent tendency to produce pale-blue offspring. 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^ in which the males alone are marked with black stri®. So again Mr. Tegetmeier has recently shewn® that dragons not rarely produce silver-coloured birds, which are almost always hens; and he himself has bred ten yuch 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 liis grand- fiither, the young female alone being silver. No doubt wdih 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 ahke ; and this very process has been followed with success by Mr. Esquilaut in the case of silver turbits. With fowls, variations of colour, limited in their transmis- sion to the male sex, habitually occur’. When tliis form of ’ Temminck says that the tail of For the common pheasant, se» the female Phasianus Sannmerrimjii Macgillivray, ‘ Hist. hrit. Birds,’ is only six inches long, ‘Planches vol. i. pp. 118-121. colorides,’ vol. v. 1838, pp. 487 and * Dr. Chapuis, ‘ I.e Pigeon Voya- 488: the measurements above given geur Beige,’ 18d.i, p. 87. were made for me by Mr. Bclator. ’ Iho ‘Held, S*i]>t. 1872. Chap. XV. Birds — Sextially Limited Inheritance. 44.7 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 both breeds. The same process would have to be followed, and the same difficulties encountered, if it were desired to make a breed with the females alone of some new colour. Lastly, our fancier might wish to make a breed with the two sexes difiering from each other, and both from the parent- species. Here the difficulty would be extreme, unless the suc- cessive 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 abori- ginal Gallus hanJdva ; 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-Umited character, otherwise it would prevent the comb of the female from lopping over. From the foregoing illustrations, wo see that even with almost unlimited time at command, it wculd be an extremely difficult and complex, perhaps an impossilJe proeess, to change one form of transmission into the other through selection. Therefore, 448 TJie Descent of Man. Past II, without distinct evidence in each case, I am unwilling to admit that this has been effected in natural species. On the other liand, 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 sbghtly altered, or specially modified for the sake of protection. 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. Conse- quently 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 ac- cession 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 in- heritance ; and this, as shewn by our previous illustration, would be extremely difficult. The more probable result of the long-continued destruction of the more brightly-coloured 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 sexually-hmited variations in brightness occurred in the females, even if they were not in the least injurious to them and consequently were not elimi- nated, yet they would not be favoured or selected, for the male usually accepts any female, and does not select the more at- tractive individuals ; consequently these variations would lie 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 duller-coloured than the males. 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 va- riations which occur late in life are commonly transmitted to the same sox in which they first appear ; whilst valuations occuning Chap. XV. Birds — Development of Spurs. 449 early in life are apt to be transmitted to both sexes ; not that all the cases of sexually-hmited transmission can thus be accounted for. It was further shewn that if a male bird varied by be- coming 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. Conse- quently 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 tliis manner when nearly mature, notwithstanding that they were exposed to some additional danger, might sui’vive, and from being favoured thi’ough sexual selection, would procreate their kind. As a relation often exists between the period of variation and the form of transmission, if the bright-colorued young males were destroyed and the mature ones were suc- cessful in their courtship, the males alone would acquire bril- liant colour’s 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 dittbrence in brilliancy between the sexes of many bkds. 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 pro- tection. 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® in which the hens were furnished with spurs ; they were good layers, but they so greatly disturbed their nests with them 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 Gallinaccaj 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 wing-spurs, wliich would not be injurious during incubation, are often as well-developed ® Bcchstein, ‘ Naturgesch. DeutschlandG,’ 1793, B. iii. s. 339. 450 The Descent of Man. Paut II. in the female as in the male ; though in not a few cases they are I’ather larger in the male. When the male is furnished with leg-spurs 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 abori- ginally been furnished with well-developed spurs, but that these had subsequently been lost through disuse or natmal selection. Hut if this view be admitted, it would have to be extended to innumerable other cases; and it implies that the female pro- genitors of the existing spur-beai-ing species were once encum- bered with an injurious appendage. In some few genera and species, as in Galloperdix, Acomus, and the Javan peacock (Favo muticas), the females, as well as the males, possess well-developed leg-spurs. Ai-e 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 spui's ; 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 spm's in the females result from different laws of inheritance having prevailed, indepen- dently 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 spm’s, we may conclude that all the successive variations were transferred to them ; and that they gradually acquired and inherited the habit of not disturbing their nests. The vocal organs and the feathers variously-modified for i3ro- ducing 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 atti-acting 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 sprmg.’ It is 7 Daines Barrington, however, cubation. He adds, that a similar thought it probable (‘ Phil. Transact.’ view may possibly account for the 1773, p. 164) that few female birds inferiority of the female to the sing, because the talent would have male in plumage, been, dangerous to them during in- Chap. XV. Birds — Length of Female s Tail. 45 T a safer conclusion that, as vocal and instrumental organs are of special service only to the males dui-ing their courtship, these organs ■were developed through sexual selection and their con- stant use in that sex alone — the successive variations and the effects of use ha-ving 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 occuring 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 dmlng the period of incubation and whilst accompany- ing her young. Hence there is not the least a priori improba- bility in the development of her tail having been checked through natui-al selection. But the females of various phea- sants, 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 kno'wn ® 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 sylvid) have the middle tail-feathers greatly length- ened, and the female makes her nest ia a hole ; and as I am informed by Mr. E. B. Sharpe these feathers become much crumpled during incubation. In these two latter cases the great lei^th of the tail-feathers 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 ; • Mr. R.imsay, in ‘ Proc. Zoolog. Soc.’ 1868, p. 50. 2 G 2 452 The Desce7it of Man. Pakt II. 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 bo 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 pro- geny, 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 pea- hen 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 aurituni) the tail is of equal length in both sexes, namely, sixteen or seventeen inches ; in the common phea- sant it is about twenty inches long in the male and twelve in the female ; in Soemmerring’s pheasant, thirty-seven inches in the male and only eight in the female ; and lastly in Eeeve’s phea- sant it is sometimes actually seventy-two 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 being more or less injiu-ious to the females of these several allied species. 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 selec- tion. 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 behef chiefly, but not exclusively, as we shall see in the next chapter, on the following statement,® 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 dull-coloured, the nest is open and exposes tho sitting bird to view. This coincidence, as far as it goes, cer- tainly seems to favour the belief that the females which sit on ’ ‘Journal of Travel,’ edited by A. Murray, vol. i. 1868, p. 78. Chap. XV. Birds — Colour and Nidificaiion. 453 open nests have been specially modified for the sake of protec- tion ; 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 duU- 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 invahdate them. There is in the first place much truth in the Duke of Argyll’s remark “ 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 cestival^ one of the most splendid birds in the United •States, the male being vermilion, and the female light brownish- green. 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 com- pensated some additional danger. klr. Wallace admits that with the King-crows (Dicrurus), Orioles, and Pittidse, the females ai’e conspicuously coloured, yet build open nests ; but he mges 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 ; and that with the birds of the third group the females are brightly colom-ed chiefly on the under surface. Besides these cases, pigeons which are sometimes brightly, and almost always con- spicuously 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 humming-birds, 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 humming-birds, which are brightly coloured, escape detection by their tints being green, for some display on their upper surfaces red, blue, and other colours.'® ‘Journal of Travel,’ edited by i* Jerdon, ‘Birds of India,’ vol. A. Murry, vol. I. 1868’ p. 281. H. p. 108. Gould’s ‘Handbook of Audubon, * Ornitnological Bio- the Birds of Australia/ vol. i. p. 463. graphy, toL i. p. 233. n P'0], instance, the female Eupo- 454 The Descent of Man. Part II. In regard to birds ■which build in holes or construct domed nests, other advantages, as Mr. Wallace remarks, besides con- cealment are gained, such as shelter from the rain, greater warmth, and in hot countries protection from the sim;'^ so that it is no valid objection to his view that many birds having both sexes obscurely coloured build concealed nests.*® The female Horn-bill (Buceros), for instance, of India and Africa is protected dnring incubation with extraordinary care, for she plasters up with her o'wn 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 ; yet female horn-bills are not more con spicuously 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 Grallinse of Australia, the Superb Warblers (Maluridm) of the same country, the Sun-birds (Nectarinise), and with several of the Australian Honey-suckers or Meliphagidse.*^ 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 con- spicuousness, 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. tomena imcroura has the head and tail dark blue with reddish loins; the female Lampomis porphyrurus is blackish-green on the upper surface, with the lores and sides of the throat crimson; the female Eulampis jugular is 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. *■* Mr. Salvia noticed in Guate- mala (‘Ibis,’ 1864, p. 375) that humming-birds 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. I may specify, as instances of dull-coloured birds building con- cealed nests, the species belonging to eight Australian genera, de- scribed in Gould’s ‘ Handbook of the Birds of Australia,’ vol. i. pp. 340, 362, 365, 383, 387, 389, 391, 414. Mr. C. Horne, ‘ Proc. Zoolog. Soc.’ 1869, p. 243. On the nidification and colours of these latter species, see Gould's ‘ Handbook,’ &c., vol. i.pp. 504 527. 455 Chai’. XV. Birds — Colour and Nidification. the remaining twenty-eight being inconspicuous.^® Nor is there any close relation within the same genus between a well-pro- nounced 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 tree-sparrow (P. montanus) hardly at all, and yet both build well-concealed nests. The two’ sexes of the common fly-catcher {Musicapa. grisola) can hardly be distinguished, whilst the sexes of, the pied fly-catcher (ilf. luctuosa) difter considerably, and both species build in holes or conceal their nests. The female black- bird (Turdus merulcC) differs much, the female ring-ouzel (P. torquatus) differs less, and the female common thrush (P. musicus) hardly at all from their respective males ; yet all build open nests. On the other hand, the not very distantly-allied water-ouzel {Cindus aquaticus) builds a domed nest, and the sexes differ about as much as in the ring-ouzel. The black and red grouse {Telrao tetrix and P. scoticus) build open nests in equally well- concealed spots, but in the one species the sexes differ gi-eatly, and in the other very little. Notwithstanding the foregoing objections, I cannot doubt, after reading Mr. V\f allace’s excellent essay, that looking to the bu’ds of the world, a large majority of the species in wMch 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^® 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, puff-birds (Oapitonidse), plantain- eaters (Musophagas), woodpeckers, and parrots. Mr. Wallace believes that in these groups, as the males gradually acquired through sexual selection then- brilliant coloui-s, these were transferred to the females and were not eliminated by natural selection, owing to the protection which they already enjoyed I have consulted, on this sub- ject, Macgillivray’s ‘ British Birds,’ and though doubts may be enter- t.ained in some case.s in regard to the degree of concealment of the nest, and to the degree of con- spicuousness of the female, yet the following birds, which .-ill Lay their eggs in holes or iu 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 ; Motacilla boarula (?); Erith.acus (?) ; Fru- ticola, 2 sp. ; Saxicola ; Euticilla, 2 sp. ; S3'lvia, 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, accortUng to the same standard, viz.. Pastor, Motacilla alba, Parus major and P. cairuleus, Upupa, Picus, 4 sp., Coracias, Alcedo, and Merops. ‘Journal of Travel,’ edited by A. Murray, vol. i. p. 78. 450 TJie Descent of Man. Paet II. from tlioir maimer 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 gi-adually rendered more and more brilliant from partaking of the colours of the male, they were gradually led to change their instmcts (supposing that they originally built open nests), and to seek protection by building domed or concealed nests. No one who studies, or instance, Audubon’s account of the differences in the nests of the same species in the Northern and Southern United States,'® will feel any great difficulty in admitting that birds, either by a change (in the strict sense of the word) of their habits, or thi-ough the natural selection of so-called spontaneous variations of instinct, might readily be led to modify their manner of nesting. This way of viewing the relation, as far as it holds good, between the bright colours of female birds and their maimer 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 siurounding surface. Nevertheless there are, as I am informed by the Eev. Mr. Tristram, some cuidous exceptions to the rule ; thus the male of the Monticola cyanea is conspicuous from his bright blue colom’, and the female almost equally conspicuous from her mottled brown and white plumage; both sexes of two species ofDro- moltea 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 in holes or crevices m the rocks. 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 induectly 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. See many statements in the the nests of lUilian birds by Eugemo ‘Ornithological Biography.’ Sec, Bettoni, in the ‘ Atti della SocietA also, some curious observations on Italiana,’ vol. xi. 18(59, p. 487. Chap. XV. Birds — Colotir and Nidification. 457 have not had their bright colom-s 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 protec- tion to the female. Thus all the species in the splendid group of the Trogons build in holes ; and Mr. Gould gives figures of both sexes of twenty-five species, in aU of which, with one partial exception, the sexes differ sometimes slightly, sometimes con- spciuously, 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 colour's of the females are rather less vivid than those of the male ; and in one splendidly-coloured species, the sexes differ so much that they were at first thought to be specifically distinct.^^ Mr. E. 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 dull- blue banded with black, the lower siuface being partly fawn- coloured, and there is much red about the head ; in the female the upper surface is reddish-brown banded with black, and the lower sui'face 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 ofDacelo the male differs from the female only in the tail being dull-blue 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 the whole upper surface in the two sexes of Carcineutes. With parrots, which hkewise build in holes, we find analogous cases ; in most of the species both sexes are briUiantly coloured and indistinguishable, but in not a few species the males ai'o coloured rather more vividly than the females, or even very differently from them. Thus, besides other strongly-marked •differences, the whole under surface of the male King Lory (^A2>rosmictus scapulatus) is scarlet, whilst the throat and chest of the female is green tinged with red : in the Euphema splendida See his ‘Monograph of the Trogonidae,’ first edition. ** Namely Cy.analcyon. Gould’s ‘Handbook to the Birds of Aus- tralia,’ vol. i. p. 133 : see, also, up. 130, 136. Pa HI’ El. 45S The Descent of Man. there is a similar difference, the face and wing-coverts moreover of the female being of a paler blue than in the male.“ In the family of the tits (Par/«ce), which build concealed nests, the female of our common blue tomtit {Parus cosruleus) is “ much “less brightly coloured "than the male; and in the magnificent Sultan yellow tit of India the difference is gi’eater.** Again in the great group of the woodpeckers,^ the sexes are generally nearly alike, but in the Megapicus validas 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 behef, had been elimi- nated. 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 con- siderations render this view extremely doubtful : the male takes a fair share in incubation,^® 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 iuctu-red ; and lastly, the colouring of the head in the two sexes often differs slightly in other ways. 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 wliich build domed or concealed nests. But similar gradations may likewise be observed in groups in which the sexes as a general rule resemble each other, but which build open nests. As I have before instanced the Australian parrots, so I may here instance, without giving any details, the Australian pigeons.*^ It deserves especial notice that in all these cases the slight Every gradation of difference between the sexes may be followed in the parrots of Australia. See Gould’s ‘ Handbook,’ &c., vol. ii. pp. 14-102. “■' Macgillivray’s ‘ British Birds,’ %'ol. ii. p. 433. Jerdon, ‘ Bii'ds of India,’ vol. ii. p. 282. All the follow'ing facts are taken from M. Malherbe’s mag- nificent ‘ Monographic des Picidees,’ 1861. Audubon’s ‘ Ornithological Bio- graphy,’ vol. ii. p. 75 ; see also the ‘Ibis,’ vol. i. p. 268. Gould’s ‘Handbook to the Birds of Australia,’ vol. ii. pp. 109- 149. Chap. XV. Birds — Colour and Nidification. 459 differences in plumage between the sexes are of the same general nature as the occasionally greater differences. A good illustra- tion 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 differ- ences 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. Tor 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 determined by the same general cause ; this being sexual selection. It is not probable, as has already been remarked, that differ- ences 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 golden-crested 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 coloxu’ be- tween the sexes, whether great or small, may to a large extent bo 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 bo capricious in their action.^* As far as I can discover there are few large groups of birds in which all the species have both sexes alike and brilliantly See remarks to this effect in my work on ‘Variation under Domesti- cation,’ vol. ii. chap. xii. 460 Part II, The Descent of Man. coloured, but I hear from Mr. Sclater, that this appears to be the case with the Musophagae or plantaiu-eaters. Nor do I believe that auy 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 (^Cotingidai) 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 sub-breeds, and in these the sexes generally differ in plumage; so that it has been noticed as an unusual circumstance when in certain sub-breeds they resemble each other. On the other hand, the domestic pigeon has likewise produced a vast number of distinct breeds and sub-breeds, and in these, vdth 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 dissimilai-ity, depending on the form of transmission, would hold good in both cases. In like manner the same form of transmission has gene- rally prevailed under nature throughout the same gi-oups, although marked exceptions to this rule occur. Thus within the same family or even genus, the sexes may be identically aUke, 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 bo distingmshed from the females, except by size ; whilst in two others, the sexes are so nnlike that they might easily be mistaken for distinct .species.^® 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 loss completely. Here protection can hardly have come into play. Mr. Blyth informs me that the females of Oriolus melano- cephalus and of some allied species, when sufficiently mature to breed, differ considerably in plumage from the adult males ; but The ‘ Ibis,’ vol, vi. 1864, p. 122. Chap. XV. Birds — Colour and Nidification. 461 after the second or third moults they differ only in their beaks having a shght greenish tinge. In the dwarf bitterns (Ardetta), according to the same anthority, “ 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 ac- quires 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 greenish-black ; 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 spoonbill (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 carolin- ensis differs very little from the male, but the appendages, which like beads of red sealing-wax ornament the wing-feathers,®“ are not developed in her so early in life as in the male. In the male- of an Indian parrakeet (Palxornis javanicus) the upper mandiblo is coral-red 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 two-year-old bu’ds 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.®' These cases must not be confounded with those where diseased or old females abnormally assume masculine characters, nor with When the male courts the fe- male, these ornaments are vibrated, and “ are shewn off to great advan- “tage,” on the outstretched wings: A. Leith Adams, ‘ Field and Forest Hambies,’ 1873, p. 153. On Ardetta, Translation of Cuvier’s ‘Regne Animal,’ by Mr. lilyth, footnote, p. 159. On the Peregrine Falcon, Mr. Blyth, in Charlesworth’s ‘ Mag. of Nat. HLst.’ vol. i. 1837, p. 304. On Dicrurus, ‘ Ibis,’ 18G3, p. 44. On the Platalea, ‘ Ibis,’ vol. vi. 1864, p. 366. On the Bombycilla, Audubon’s ‘Orni- tholog. Biography,’ vol. i. p. 229. On the Palseornis, 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. Analo- gous cases with the females of Petrocossyphus are given by Mr, H. B. Sharpe, ‘Proo. Zoolcg. See. 1872, p. 496. 462 The Descent cf Man. Paet ir. those where fertile lemales, whilst young, acquire the characters of the male, thi'ough variation or some unknown cause.®* But all these cases have so much in common that they depend, according to the hypothesis of pangenesis, on gemmules derived trom each part of the male being present, though latent, in the female ; their development following on some slight cliange in the elective affinities of her constituent tissues. 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, &c., of egrets, heron.s, 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 dtu’ing the period of incubation than dming the winter ; but such birds as herons and egrets would be able to defend them- selves. As, however, plumes would probably be inconvenient and certainly of no use during the whiter, it is possible that the habit of moulting tivice in the year may have been gradually acquired through natmal 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 breeding-season, — or when the males acquire at this season such long wing or tail-feathers as to impede their flight, as with Cosmetornis and Vidua, — it certainly at first appeal’s 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 Gallinacese, renders a double moult impossible, for the ptarmigan moults thrice in the year.®® 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 acquhed tliis habit on account of the inconvenience or danger which they would otherwise have suffered. Of these latter cases Mr. Blyth also recorded a similar case (‘ Ornith has recorded (Translation of Cuvier’s Biog.’ vol. v. p. 519) with Pyranga ‘Rfegne Animal,’ p. 158) various astiva. instances with Lanius, Ruticilla, See Gould’s ‘ Birds of Great Liraria, and Anas. Audubon has Britain.’ OuAP. XVI. Birds — Inheritance Limited by Age. 463 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 whiter covering ; and that variations in the plumage occurring during the summer were accumulated through sexual selection, and transmitted to the oif- spring 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 trans- mission 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 protec- tion, 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 foUo'wing chapter, of the differences in plumage between the young and old. CHAPTEE XVI. Birds — concluded. The immature plumage in relation to the character of the plumage in both sexes when adult — Six classes of cases — Sexual differences between the males of closely-allied or representative species^ — The female as- suming the characters of the male — Plumage of the young in relation to the summer and winter plumage of the adults — On the increase of beauty in the birds of the world — Protective colouring — Conspicuously- coloured birds — ^Novelty appreciated — Summary of the four chapters on Birds. \Ve must now consider the transmission of characters, as limited by age, in reference to sexual selection. The truth and im- portance 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 mo, may be included, it will be well to make a few preliminary remarks. Part IL 4.64 The Descent of Ma7i. 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 stnictures, to the re- tention 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 proofe that such a state of things was formerly possible. Young hons 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 yoimg covered with white spots, as are likewise some few species in the adult state. So again the young in the whole family of pigs (Suidffi), and in certain rather distantly alhed animals, such as the tapu’, are marked with dark longitudinal stripes; but here we have a chai’acter apparently derived from an extinct progenitor, and now preserved by the young alone. In aU 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 principle of inheritance at corre- sponding ages. 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 Gallinacese, and of some distantly allied birds such as ostriches, are covered with longitudinally striped down ; but this character iDoints back to a state of things so remote that it hardly concerns us. Young cross-bills (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, gi-eenfinch, and some other allied species. The young of many kinds of buntings (Emberiza) resemble one another, and like- wise the adult state of the common bunting, E. miliaria. In almost the whole large gi-oup of thrushes the young have their- breasts spotted— a character which is retained thi-oughout hfe by many species, but is quite lost by others, as by the Turdus migralorius. So again with many thi-ushes, 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. Chap. XVL Birds — Inheritance Limited hy Age. 465 The young of many species of shrikes (Lanins), of some wood- peckers, and of an Indian pigeon {Chalcopha'ps indicus), are transversely striped on the under surface; and certain allied species or whole genera are similarly marked when adult. In some closely-alhed and resplendent Indian cuckoos (Ohryso- coccyx), 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 iu plumage an allied genus, Dendrocygna, when mature.' Similai- facts will hereafter be given in regard to certain herons. Young black grouse ( Tetrao tetrix) resemble the young as well as the old of certain other species, for instance the red grouse or T. scoticus. Finally, as Sir. Blyth, who has attended closely to this subject, has well remarked, the natural affinities of many species aiu 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 con- firms 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 pro- genitors, yet there are many other birds, both duU-coloured and bright-coloured, 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 progenitors were similarly coloured. 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. Eules of this kind were first enounced by Cuvier ; but with the progress of knowledge they require some modification and am- plification. 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 • 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 ‘ Rfegne Animal,’ p. 159. I give the case of Loxia on Mr Blyth’s information. On thrushes, see also Audubon, ‘ Ornith. Biography,’ vol. ii. p. 195. On Chrysococcyx and Chalcophaps, Blyth, as quoted in Jerdon’s ‘ Birds of India,’ vol. iii. p. 485. On Sar- kidiornis, Blyth, in ‘Ibis,’ 1867, p. 175. o H 466 Pabt U. The Descent of Man. 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 hero 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 often of a different shape. EULES OB CLASSES OF CASES. 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 young of both sexes in their first plumage resemble the adult male. III. When the adult male resembles the adult female, the young of both sexes have a peculiar first plumage of their own, as with the robin. IV. When the adult male resembles the adult female, the young of both sexes in their first plumage resemble the adults, as with the kingfisher, many parrots, crows, hedge-warblers. 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 again they may differ greatly from the adults in both their seasonal plumages. 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 yoimg females more or less closely the adult females. Class I. — 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 bo given; it will suffice to call to mind the common pheasant, duck, and house- sparrow. The cases under this class graduate into others. Thus the two sexes when adult may differ so slightly, and the young so shghtly from the adults, that it is doubtful whether Chap. XVI. Birds — Young like A dtcU Females. 467 Btich 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 weU 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, &c., the young of both sexes resemble the adult female.^ We see the same fact exhibited still more clearly in certain anomalous cases ; thus the male of Heliothrix auriculata (one of the humming- buds) differs conspicuously from the female in. having a splendid gorget and fine ear-tufts, 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 matmity, which is a mos^ unusual circumstance.® Again, the plumage of the male goos- ander {Mergus merganser) is more conspicuously coloured than that of the female, with the scapular and secondary wing-feathers 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 nan-ower, than in the adult male.* When the young and the females closely resemble each other and both differ from the males, the most obvious conclusion is ^ See, for instance, Mr. Gould’s account (‘ Handbook to the Birds of Australia,’ vol. i. p. 133) of Cyanal- •cyon (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. gaudichaitdi 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 Jerdou (‘ Birds of India,’ vol. i. p. 260) on the Faleeornis rosa, in which the young are more like the female than the male. See Audubon (‘ Ornith. Biograph.’ vol. ii. p. 475) on the two sexes and the young of Columba passerina. ^ I owe this infoi'mation to Mr. Gould, who shewed me the speci- mens ; see also his ‘ Introduction to the Trochilidaj,’ 1861, p. 120. * Macgillivray, ‘ Hist. Brit. Birds , vol. V. pp. 207-214. 2 II 2 468 The Descent of Man. Pabt IL that the males alone have been modified. Even in the ano- malous cases of the Heliothrix and Mergus, it is probable that originally both adult sexes were furnished — the one species with a much elongated tail, and the other with a much elon- gated crest — these characters having since been partially lost by the adult males from some unexplained cause, and transmitted in their diminished state to their male ofispring alone, when arrived at the correspondiflg 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 re- markable facts recorded by Mr. Blyth,® with respect to closely- allied species which represent each other in distinct countries. Eor with several of these representative species the adult males have undergone a certain amount of change and can be dis- tinguished; 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 honey-suckers (Nectarinia), shrikes (Tephrodomis), cer- tain kingfishers (Tanysiptera), Kalij pheasants (Gallophasis), and tree-partridges (Arboricola). In some analogous cases, namely with birds having a different summer and winter plumage, but with the two sexes nearly alike, certain closely-alhed 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 closely-allied Indian wag-tails or Motacillse. Mr. Swinhoe® 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 ® See his admirable paper in the several distinct races, solely by ‘ Journal of the Asiatic Soc. of comparing the adult males. Bengal,’ vol. xix. 1850, p. 223 ; see ® See also Mr. Swinhoe, in ‘ Ibis.’ also Jerdon, ‘ Birds of India,’ vol. i. July 1863, p. 131 ; and a previous introduction, p. xxix. In regard to paper, with an extract from a note Tanysiptera, Prof. Schlegel told Mi’, by Mr. Blyth, in ‘Ibis, Jan. 1801, Blyth that he could distinguish p. 25. Chap. XVI. Birds — Young like A dtdt Females. 469 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 breeding-season, and transmitted to the adults of both sexes at the corresponding season, has been modified, whilst the winter and immature plumages have been left unchanged. The question naturally arises, how is it that in these latter cases the winter -plumage of both sexes, and in the former cases the plmnage of the adult females, as well as the immature plumag6 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 con- ditions, but we can hardly attribute to this action the modi- fication of the plumage in the males alone, seeing that the females and the yoimg, though similarly exposed, have not been affected. Hardly any fact shews us more clearly how subor- dinate 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 wide-spread 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 change — the taste or admiration of the female — will 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 newly-acquired 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 sexes. Although the females of the above closely-allied or repre- sentative species, together with their young, differ hardly at all 470 The Descent of Man. Paet II. 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 Gallinacea}: 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 fowlr —resemble one another very closely in colour, whilst the males differ to an extraordinary degree. So it is with the females of most of the Cotingidse, 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. papriana differ from each other more than do their respective males 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,® 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 sub-breeds of the game-fowl, in which the females are very different, whilst the males can hardly be distinguished.® 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 hero 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 sh'ghtly or considerably ; and if we compare the females of the greenfinch, chaflSlnch, goldfinch, bullfinch, crossbill, sparrow, &c., we shall see that they differ from one ■ Wallace, ‘The Malay Archi- ‘Ibis,’ 1866, p. 275. pelago,’ vol. ii. 1869, p. 394. ’‘Variation of Animals, &c., * These species are described, with under Domestic.ation,’ vol. i. p. 251. coloured figures, by M. F. Pollen, in Chap. XVI. Birds — Young like Adult Females. 47 r another chiefly in the points in which they partially resemble their respective males ; and the colours of the males may safely he 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 ocein 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 guinea-fowl 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 later-gained characters. For instance, the female and the young of the black-grouse ( Tetrao tetrix) resemble pretty closely both sexes and the young of the red-grouse {T. scoticus) ; and we may consequently infer that the black-grouse is descended from some ancient species, of which both sexes were coloured in nearly the same manner as the red-grouse. As both sexes of this latter species are more distinctly barred during the breeding season than at any other time, and as the male differs slightly from the female in his more stongly-pronounced red and brown tints,’“ 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 the nearly similar plumage of the female black- grouse was similarly produced at some former period. But since this period the male black-grouse has acquired his fine black plumage, with his forked and outwardly-curled tail- feathers; 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 (Afferent by the transference in various degrees, of characters acquired by the males through sexual selection, both during '» Macgillivray, ‘Hist. British Birds,’ vol. i. pp. 172-174. 472 The Descent of Man. Paet II. 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 red-throated blue- breast ( (72/anecMto 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 Gallinacese offer many analogous cases ; for none of the species, such as partridges, quails, guinea-fowls, &c., 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 vxd- Uchii) 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 briUiantly 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 ti'ansmitted 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 transmitted to both sexes. In addition to the effects of the partial transference of charac- ters from the males to the females, some of the differences between the females of closely aUied species may be attributed to the direct or definite action of the conditions of hfe.” 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, “ See, on this subject, chap, ixiii. in the ‘ Variation of Animals and Plants under Domestication.’ Chap. XVI. Birds — Young like A dull Females. 47 3 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 iutercrossing of the many individuals belonging to the same species would ultimately tend to make any change of colour, thus induced, uniform in character. 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 foim 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 hmited, 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 j 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 elimin- ated 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 hedge- warbler or kitty-wren {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 house-sparrow, in which the male differs much from the female, but does not exhibit any bright tints. No one probably -will dispute that many gal^aceous 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 black-grouse 474 The Desceiit of Man. Past II. and red-gronse 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 iabits 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 dull-coloured without the young participating in the same change; for there are no in- stances, 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.'* 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 trans- mitted only to the adult male offspring. Any variations in brightness occurring in the females or in the young, would have- Audubon, ‘ Ornith. Biography,’ also tho case before given of /iwio- vol. i. p. 193. Macgillivray, ' Hist, picus carlotta. Brit Birds’ vol. iii. p. S5. See Chap. XVI. Birds — Voting like Adult Males. 475 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 inter- crossiQg 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 protection, so as to have acquired the same dull coloured plumage. Class II. When the adult female is more conspicuous than the adult male, the young of hoth sexes in their first plumage resemile the adult male. — 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 poinV® 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 aU that I have been able to find. In one section of the genus Tumix, quail-like birds, the female is invariably larger than the male (being nearly twice as largo in one of the Australian species), and this is an unusual circum- stance with the Gallinacese. In most of the species the female is more distinctly coloured and brighter than the male,^'* 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 ‘Westminster Review,’ July, 178, 180, 186, and 188. In the 1867, and A. Murray, ‘ Journal of British Museum specimens of the Travel,’ 1868, p. 83. Australian Plain-wanderer (Pedio- “ For the Australian species, see nomus torqmtus) may be seen, Qould’s ‘ Handbook,’ &c., vol. ii. pp. shewing similar sexual differences. 476 TJie Descent of Man. Part n. females and not the males are often kept by the natives for fighting, like game-cocks. As male birds are exposed by the English bird-catchers 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 ear-shot run rapidly to the “ spot, and commence fighting -with the caged bird.” In this way from twelve to twenty birds, aU 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 trath of this assertion, which is supported by some observations made in China by Mr. S-winhoe.*® Mr. Blyth believes, that the young of both sexes resemble the adult male. The females of the three species of Painted Snipes (Ehynchasa, fig. 62) “ are not only larger but much more richly coloured than “ the males.” 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 Rhynchsea australis it is simple in the male, whilst in the female it makes four distinct convolutions before entering the lungs. The female therefore of this species has acquired an eminently masculine character. Mr. Blyth ascertained, by exanaining many speci- mens, that the trachea is not convoluted in either sex of R. hmgalensis, 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 closely-allied ■forms, though it is a very rare circumstance when such differ- ences relate to the female sex. The young of both sexes of R. lengalensis in their first plumage are said to resemble the mature male.'* There is also reason to beheve that the male undertakes the duty of incubation, for Mr. Swinhoe found the females before the close of the summer associated in flocks, as occurs with the females of the Turnix. The females of Phalaropus fulicarius and P. hyperhoreus 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 Jordon, ‘Birds of India,’ vol. ” Gould’s ‘Handbook to the iii. p. 596. Mr. Swinhoe, in ‘Ibis,’ Birds of Australia,’ vol. ii. p. 275. 1365, p. 542 ; 1866, pp. 131, 405. ’* ‘ The Indian Field,’ Sept. 1858, Jerdon, ‘ Birds of India,’ vol. p. 3. iii. p. 677. ” ‘ Ibis,’ 1866, p. 298. Chap. XVI. Birds — Young like Adult Males. 477 male alone of P.fulkarius undertakes the duty of incubation ■; this is likewise shewn by the state of his breast-feathers during the breeding-season. The female of the dotterel plover {Eudro- mias morinellus) is larger than the male, and has the red and Fig. 62. Ehynchaia capensls (from Brebm). 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.^® I have not been For these several statements, see Mr. Gould’s ‘Birds of Great Britain.’ Prof. Newton informs me that he has long been convinced, &om 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 478 The Descent of Man. Paut 11, 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.’*^ The female is said by Mr. T. W. "Wood “ to exhibit during the breeding season a most pugnacious disposition; and her wattles then become enlarged and more brilliantly coloured. So again the female of one of the emus {Dromceus irroratus) is considerably larger than the male, and she possesses a slight top-knot, but is otherwise indistinguishable in plumage. She appears, however, “ to have greater power, “ when angry or otherwise excited, of erecting, like a turkey- “ cock, 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 rmsafe to put the parents together, violent “ quarrels being the inevitable result, in which the female gene- “ rally comes off conqueror.” 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 It IS, as he informs me, with Limosa lapponica and some few other Waders, in which the females are larger and have more strongly con- trasted colours than the males. ** 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 Student,' April, 1870, p. 124. ” See the excellent account of the habits of this bird under confine- ment, by Jlr. A. W. Bennett, in ‘ Land and Water,’ May, 1868, p. 233. Chap. XVI. Birds — Young like Adtdt Males. 479 plumes -with more strongly contrasted colours ; nevertheless he ■undertakes the whole duty of incubation.^^ 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 carrion-hawk of the Falkland Islands {Milvago leucurus) I was much surprised to find by dissection that the individuals, which had all their tints strongly pronoimced, with the cere and legs orange-coloured, were the adult females; whilst those with duller plumage and grey legs were the males or the young. In an Australian tree-creeper (^CUrmcteris erythrojgs) the female differs from the male in “being adorned with beautiful, ra- “ diated, rufous markings on the throat, the male having this “part quite plain.” Lastly, in an Australian night-jar “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.” “ 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 differ- ence, also, between the sexes is incomparably less than that which frequently occurs m 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 Mr. Sclater, on the incubation of the Struthiones, ‘ Proc. Zool. Soc.,’ June 9, 1863. So it is with the Ehea 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 eggs and of the young, just as does the male of the common species of Rhea. For the Milvago, see ‘ Zoology of the Voyage of the Beagle, ’ Birds, 1841, p. 16. For the Climac- teris and night-jar (Eurostopodus), see Gould’s ‘ Handbook to the Birds of Australia,’ vol. i. pp. 602 and 97. The Hew Zealand shieldrake (Ta- doma variegatd) offers a quite ano- malous 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 fea- thers, 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 (‘ Proc. Zool. Soc.’ 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. 480 The Descent of Man. Pa3t n. 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 sufBciently 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 shght degree less conspicuously coloured than the females, but are smaller and weaker. They have, moreover, not only acquired the maternal instinct of incubation, but ai’e 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 ot structure, has been effected between the two sexes. 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 males — and in the case of one Indian Turnix the females are said to be “much more commonly met with than the “ males.” — 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 gi’ouse. 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 ex- cited 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 attrac- tions of the females; the males and the young being left not at all, or but little mo^fied. Class III. When the adult male resemlles the adult female, the young of both sexes have a ^peculiar first plumage of their own. — In this class the sexes when adult resemble each other, and differ from the young. This occurs with many bnds of many kinds. The male robin can hardly be distinguished from the female, but the young are widely different, with their mottled dusky- olive and brown plumage. The male and female of the splendid Jei-don, ‘ Birds of India,’ vol. iii. p. 098. Chap. XYL Birds — Young tike both A dults. 481 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 occiu’s with brilliant males when they, arc 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 slate-coloured, 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. Y^en 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 young. Class IV. When the adult male resembles the adult female, the young of both sexes in their first filumage resemble the adults. — In this class the young and the adults of both sexes, whether briUiantly 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 hedge-warbler or kitty-wren. But the similarity in plumage between the yoimg 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 coloui-ed than the adults, but many of the feathers on the lower surface are edged with brown,^' — 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 parro- keets (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.*® Both sexes and the young of the common jay are closely similar ; but in the Canada jay (P erisoreus canadensis) the young differ so much horn their parents that they were formerly described as distinct species.*® Jerdon, ‘Birds of India,’ vol. i. pp. 222, 228. Gould’s ‘ Handbook to the Bird.s of Australia,’ vol. i. pp. 124, 130. Gould, Ibid. vol. ii. pp. 37, 46, 56. Audubon, ‘ Ornith. Biography, vol. ii. p. 55. 2 I 482 Pabt II, The Descent of Man. I may remark before proceeding that, under the present and next two classes of cases, the facts are so complex and the con- clusions so doubtful, that any one who feels no especial interest in the subject had better pass them over. The brilliant or conspicuous colours which characterise many birds in the present class, can rarely or never be of service to them as a pro- tection ; so that they have probably been gained by the males through sexual selection, and then transferred to the females and the yoimg. 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 nrocess of selection would be likely to occur, owing to the greater eagerness of one sex than the other, and whether it would be more efScieut 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 gradually-acquired colours, either equally or almost equally, to their offspring of both sexes. Another point is more doubtful, namely, whether the successive variations first appeared in the males after they 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 con'esponding ages fails, the offspring often inherit characters at an earlier age than that at which they first appeared in their parents.’” Cases apparently of this kind have been observed with birds in a state of nature. For instance Mr. Blyth has seen specimens of Lanins rufw and of Colymbus glacialis which had assumed whilst young, in a quite anomalous manner, the adult plumage of their parents.’* Again, the young of the common swan {Cygiius olor^ do not cast off their dark feathers and become white until eighteen months or tw'o 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 "> ‘Variation of Animals and ’* Chavlcsworths’ ‘ Mag. of Nat. Plants under Domestication,’ vol. ii. Hist.' vol. i. 1837. pp. 305, 306. p. 79 Chap. XVI. Birds — Yoting like both A dtdts. 483 were not albinoes, as shewn by the colour of their beaks and legs, which nearly resembled the same parts in the adults.^^ 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 lesemble each other, by the curious case of the genus Passer.^^ In the house-sparrow (P. domesticus) the male diflers 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 house-sparrow approximately shew us the plumage of the progenitor of the genus. Now with the tree-sparrow (P. montanus) both sexes and the young closely resemble the male of the house-sparrow ; so that they have all been modifled in the same manner, and all depart from the typical colom-ing of their early progenitor. This may have been effected by a male ancestor of the tree-sparrow 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 yoimg ; 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 corresponding ages, at some subsequent period to his young. 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 transmis- sion 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, second, and fourth classes of cases ; but they fail in the third, often in the fifth,^® 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 protu- berances on the heads of birds. Whether or not the two rules generally ‘ 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 (jCygnus olor). 1 am indebted to Mr. Blyth for information in regax’d to this genus. The sparrow of Palestine belongs to the sub-genus Petronia. For instance, the males of Tanagra ccstim and Fringilla cyanea require three years, the male of Fringilla ciris four years, to com- plete their beautiful plumage. (See Audubon, ‘ Ornith. Biography,’ vol. i. p. 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 ot the September in the followins year. 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. ’ 2 I 2 484 The Descent of Man. Part II. hold good, we may conclude from the facts given in the eighth chapter, that the period of variation is one important cdoment 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 east off before the first wing-feathers are fuUy grown ; and we cannot believe that this was the primordial state of things. When the period of moulting has been accelerated, tlie age at which the colours of the adult plumage are first developed will falsely appear to us to be earlier than it reaUy is. This may be illustrated by the practice followed by some bird-fanciers, who pull out a few feathers from the breast of nestling bullfinches, and from the head or neck of young gold-pheasants, in order to ascertain their sex : for in the males, these feathers are immediately replaced by coloured ones.^® 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 remark- able fact that various birds occasionally breed whilst retaining their immature plumage.^' 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, &c., 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.^® If the young of any species in their immature plumage were more successful in winning partners than the adults, the adult plumage would probably Mr. Blyth, in Charlesworth’s • Mag. of Nat. Hist,’ vol. i. 1837, p. 300. Mr. Bartlett has informed me in regard to gold-pheasants. I have noticed the following cases in Audubon’s ‘Ornith. Bio- graphy.’ The redstart of America, (Muscapica rutioilla, vol. i. p. 203). The iSi's tantalus takes four years to come to full maturity, but some- times 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 Ardca oxrulea are blue, and the yoMg 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). Tht; White-headed Eagle (Falco leucoce- phalus, vol. iii. p. 210) is likewise known to breed in its immature state. Some species of Oriolus (ac- cording to Mr. Blyth and Mr. Swinhoe, in ‘Ibis,’ July 1863, p. 68) likewise breed before they attain their full plumage. See the last foot-note. Chap. XVI. Birds — Young like both Adults. 4S5 Boon 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.^“ 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 waste of power. The plumage of cei tain 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.*^ 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 con- tinuous growth. Most fishes continue increasing in size, as long as they are in good health and have plenty of food ; and a somewhat similar law may prevail with the plumes of birds. Class V. When the adults of both sexes have a distinct winter and cummer 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, again, they may differ greatly from the adults in both their seasonal plumages. — The cases in this class are singularly complex ; nor is this siuprising, as they depend on inheritance, limited in a greater or less degree in three difi'erent ways, namely, by sex, age, and the season of the year. In some cases the individuals of the same species pass through at least live 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,^* the young generally resemble the females, — as with the so-called goldfinch of North America, and apparently with the splendid Maluri of Australia.^^ With those species, the sexes of which are alike during both the summer and winter, the young ma}’ 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 am- phibians have been known to breed whilst retaining their larval struc- tui-e. Fritz Muller has shewn (‘ Facts and Arguments for Darwin,’ Eng. trans. 1869, p. 79) that the males of several amphipod crusta- ceans become sexually mature whilst young; and I infer that this is a case of premature breeding, because they have not as yet acquired their fully-developed claspers. All such facts are highly interesting, as bearing on one means by which species may undergo great modifi- cations of character. 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 Nderlandaises,’ tom. vi. 1871. — On Ardea, Audubon, ibid. vol. iii. p 139. For illustrative cases see vol. iv. of Macgillivr,ay’3 ‘Hist. Brit. Birds ;’ on Tringa, &c., pp. 229, 271 ; on the Machetes, p. 172; on the Charadrius hiaticula, p. 118 ; on the Charadrius pluviaKs, p. 94. For the goldfinchofN. America, Fringilla tristis, Linn., see Audubon. ‘Ornith. Biography,’ vol. i. p. 171. For the Maluri, Gould’s ‘ Handbook to the Birds of Austr.alia, vol. i. p. 318 486 The Descent of Man. Paut II. l esemble the adults, firstly, in their winter dress ; secondly, and this is of much rarer occurrence, in their summer dress ; thirdly, they may bo 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 (JBwphm coro- mandus), in which the young and the adults of both sexes arc white during the winter, the adults becoming golden-buff during the summer. With the gaper {Anastomns 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 adtdts becoming white during the summer.^^ As an instance of the second case, the young of the razor-bill (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 (FringUla leueophrys'), as soon as fledged, have elegant white stripes on their heads, which are lost by the young and the old during the winter.'*^ With respect to the third case, namely, that of the young having an intermediate character between the summer and winter adult plumages, Yarrell^® 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 young alone being white. I win 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 breeding-season, having been limited in their trans- mission 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 ac- quirement 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, aU 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 be worth while to attempt to follow out these complex relations. ■*“ 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. On the Alca, see Macgillivray, Hist. Brit. Birds,’ vol. v. p. 347. On the Fringilla leueophrys, Au- dubon, ibid. vol. ii. p. 89. I shall have hereafter to refer to the young of certain herons and egrets being white. “ ‘ History of British Birds,’ vol. i. 1839, p. 159. Chap. XVJ. Birds — Young like both A dtilts. 487 Class VI. 27te 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 females. — The cases in the present class, though occiirring 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 atrioapilla) has a black head, that of the female being reddish- brown ; 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 shewing more pure white.^® The males of a forest-thrush 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 tail-feathers edged with blue, whilst those of the female are edged with brown.^' 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 wing-feathers become blue before the others. The most probable view with reference to the oases in the present class is that the males, difierently from what occurs in Class I., have transmitted their colours to their male ofispring 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.'"® In Aithurus polytmus, a humming-bird, the male is splendidly coloured black and green, and two of the tail-feathers 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 tail-feathers soon become elongated. I owe this information to Mi\ Gould, who has given me the following more striking and as yet unpublished case. Two humming-birds belonging to the genus Eustephanus, both beautifully coloured, inhabit the small island of Juan Fernandez, and have always been ranked as specifically dis- tinct. But it has lately been ascertained that the one, which is of a rich chesnut-brown colour with a golden-red 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 Audubon, ‘ Ornith. Biography,’ vol. i. p. 113. Mr. C. A, Wright, in ‘Ibis,’ vol. vi. 1864, p. 65. Jerdon, ‘ Birds of India,’ vol. i. p. 615. See also on the blackbird, Blyth in Charlcs- worth’s ‘ Mag. of Nat. History,’ vol. i. 1837, p. 113. “ 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 with the nestlings of a blue nuthatch, DendropMla 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 hum- ming-bird, like the following one of Eustephanus. 4^8 The Descejit of Man. Part II. somewhat resemble the adults of tlie corresponding sex, the resemblance gradually becoming more and more complete. 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 Bliynchsea 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 humming-birds 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 tlie 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, mieht 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 male — first 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 Imow, but with respect to the form of transmission, one important determining cause seems to be the age at which the variations fii’st appear. 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 selected — on the contrary being often eliminated as dangerous — whilst similar variations occui’ring 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 iuto 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 coloiued : Chap. XVI. Birds — Colour and Protection. 489 for no instance is known, as far as I can discover, of the young of duU-colom-ed species displaying bright colours, or of the young of bright-coloured 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 bright-coloured, and as these form whole 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 partial record. On the Colour of the Plumage in relation to Protection. — 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 over- heard. Mr. Wallace remarks^” 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, hov»r difficult it is to distinguish parrots in a leaf-covered tree. Nevertheless, we must remember that many parrots are ornamented with crimson, blue, and orange tints, which can hardly be protective. Wood- peckers are eminently arboreal, but besides green species, there are many black, and black-and-white kinds — all the species being apparently exposed to nearly the same dangers. It is therefore probable that with tree-haunting birds, strongly-pro- nounced colours have been acquired through sexual selection, but that a green tint has been acquired oftener than any other, from the additional advantage of protection. In regard to birds which live on the ground, every one admits that they are coloui-ed so as to imitate the surrounding surface, How difficult it is to see a partridge, snipe, woodcock, certain plovers, larks, and night-jars when crouched on ground. Animnlq inhabiting deserts offer the most striking cases, for the bare surface affords no concealment, and nearly all the smaller quad- rupeds, reptiles, and birds depend for safety on their colovu's. Mr. Tristram has remarked in regard to the inhabitants of the Sahara, that all are protected by their “isabelline or sand- ‘Westminster Review,’ July, 1867, p. 5. 490 The Descent of Man. Part II. “ colour.” Calling to my recollection the desert-birds of South, America, as well as most of the ground-birds of Great Britain, it appeared to me that both sexes in such cases are generally coloured nearly alike. Accordingly, I apphed to Mr. Tristram with respect to the birds of the Sahara, and he has kindly given me the following information. There are twenty-six 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 buds it differs from that of their congeners. Both sexes of thirteen out of the twenty-six species are coloured in the same maimer ; 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 desert-birds. Of the other thirteen species, three belong to genera in which the sexes usually differ from each other, yet here they have the sexes alilce. 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 sui'faces 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 pro- tected, 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 sexually-limited transmission. In all parts of the world both sexes of many soft-billed birds, especially those which frequent reeds or sedges, are obscurely coloured. No doubt if theh 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 dull-coloured, often differ much from their females (as with the common sparrow), and this leads to the belief that such colours have been gained tlirough sexual ■selection, from being attractive. Many of the soft-billed birds are songsters ; and a discussion in a former chapter should not ““ ‘ Ibis,’ 1859, vol. i. p. 429, et his cxperieuce of the Sahara, this soq. Dr. Kohlfs, however, remarks statement is too strong, to me in a letter that, according to Chap. XVI. Birds — Conspicuous Colours. 491 be forgotteiij 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 jack-snipe, woodcock, and night-jar, are likewise marked and shaded, according to om 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, maybe 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 attribute the result to the direct action of the conditions of life. Both sexes of many birds are conspicuously, though not brilliantly coloured, such as the niunerous black, white, or piebald species; and these colours are probably the result of sexual selection. With the common blackbird, capercailzie, blackcock, black scoter-duck (Oidemia), and even with one of the birds of paradise (^Lopliorina 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 black-cock and capercailzie, in the brightly and variously coloured beak of the scoter-drake (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.*^ The naked skin, also, at the base of the No satisfactory explanation has size, and still less of the bright ever been offered of the immense colours, of the toucan’s beak. Mr. 492 TJie Desceyit of Man. Past II, beak aud round the eyes is Likewise often brilliantly coloured ; and Mr. Gould, in speaking of one species,®^ 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 ■nuth plmnes so long as to impede their flight. In the same manner, as the males alone of various species arc black, the females being dull-coloured ; so in a few cases the males alone are either wholly or partially white, as with the several bell-birds of South America (Chasmorhynchus), tho Antarctic goose {Bernida. antarctica), the silver-pheasant, &c., 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, &c., 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, tropic- birds, &c., and with the snow-goose (Anser hyperhoreus). 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 snow-white adult plumage serves as a protection. In the Anastomus oscitans, we have still better’ evidence that the white plumage is a nuptial character, for it is developed only during the summer ; the young in their imma- ture 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 dui’ing the winter and in the young state. On the other hand. 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 ex- tracting eggs and young birds from the nests of other birds. But, as Mr. Bates admits, the beak “ can “ scarcely be considered a very per- “ fectly-formed 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 Nica- ragua,’ 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. Ramphastos carinatus, Gould’s ‘ Monograph of Ramphastidie.' Chap. XVI. Birds — Conspicuous Colours. 493 with the smaller gaUs, or sea-mews (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 breeding-season. These latter cases offer another instance of the capricious manner in which sexual selection appears often to have acted.“ 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. Xo 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 possibly serve the same end as the call-notes of many land-birds.®* 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 fii-st finders, the indi- viduals 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 black-necked 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 On Larus, Gavia, and Sterna, see Macgillivray, ‘ Hist. Brit. Birds,’ vol. V. p. 515, 584, 626. On the Anser hyperboreus, Audubon, ‘Or- nith. Biography,’ vol. iv. p. 562. On the Anastomus, Mr. Blyth, in ‘ Ibis,’ 1867, p. 173. 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 duivng the breeding- season. 494 The Descent of Man. Paet II. parts of a purer white, and the variously coloured dark parts of still darker tints than the female. 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 rose-coloured collar instead of “ a bright “ emeraldine narrow green collar;” or in the male having a black collar instead of " a yellow demi-collar in front,” with a pale roseate instead of a plum-blue head.®* As so many male birds have elongated tail-feathers or elongated crests for their chief ornament, the shortened tail, formerly described in the male of a humming-bird, and the shortened crest of the male goosander, seem like one of the many changes of fashion which we admire in our own dresses. Some members of the heron family offer a still more curious case of novelty in colouring having, as it appears, been appre- ciated for the sake of novelty. The young of the Ardea asha are white, the adults being dark slate-coloiu’ed ; and not only the young, but the adults in their winter plumage, of the allied Bufhus coromandus are white, this coloiu’ changing into a rich golden-buff during the breeding-season. It is incredible that the young of these two species, as well as of some other members of the same family,®® 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 strongly-pronounced tints. But if we could look still further back to the still earlier progenitors of these two species, we should probably see the adults dark- See Jerdon on the genus specific names. Audubon (‘ Ornith . Palffiornis, ‘Birds of India,’ vol. i. Biography,’ vol. iii. p. 416 ; vol. ir. p. 258-260. P- ^8) seems r.ather pleased at the The young of Ardea rufescens thought that this remarkable change •and A. emmlea of the U. States are of plumage will greatly “ disconcert likewise white, the adults being “ the systematists.” coloured in accordance with their Chap. XYI. Birds — Novelty admired. 495 coloured. 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 Ardta gularis, the colours of which are the reverse of those of A. asha, for the yoimg are dark-coloured and the adults white, the young having retained a former state of plumage. It appears there- fore that, during a long line of descent, the adult progenitors of the Ardea asha, the Buphus, and of some allies, have under- gone 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 golden-buff tints. These successive changes are intelligible only on the principle of novelty having been admired by birds for its own sake. 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 con- sequently 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 ear’s, distorted heads, &c. ; 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 Imow that dovecot pigeons do not willingly associate with the variously coloured fancy breeds ; that albino bhds 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 The Descent of Man. Pabt II. 496 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 animnlK admiring for a very long period the same general style of ornamen- tation or other attractions, and yet appreciating slight changes in colours, form, or sound. Summary of the Four Chapters on Birds. — Most male birds are highly pugnacious during the breeding-season, 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 g^iu 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, top-knots, 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 breedmg-season, or the tints then become more vivid. Certaiu 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 efiect ; 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 marked preference or antipathy for certain individual males. If it be admitted that the females prefer, or are unconsciously Chap. XYI. Birds — Summary. 497 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 closely-allied 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 imme- diately 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 grada- tions, 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 tail-feathers of the peacock, and the ball and socket ocelli on the wing-feathers of the Argus pheasant. It is evident that the brilhant colours, top-knots, fine plumes, &c., 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 dming 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 strongly marked individual differences ; and such differences will have afforded an excellent ground- work for the action of sexual selection. 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 kno^vn ; 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 498 The Descent of Ma?i. Pabt II. tranfimitted, every possible gradation may be found, even within the same genus, from the closest similarity to the widest dis- similai'ity between the sexes. With many closely-allied 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 tihe 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 strongly-pronounced colours and other ornaments. The indi- viduals of both sexes, however affected, will have been kept at each successive period nearly uniform by the free intercrossing of many individuals. 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 duU-colom’ed, the male being stfll kept bright-coloured, by the selection of successive variations, which were from the fii’st 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 modified so that they were led to build domed or concealed nests. In one small and cm-ious 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 quarrel- some 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 charros endeavour to attract the males, we can understand how it is that they have gi-adually been rendered, by sexual selection and sexually-limited transmission, more beautiful than the males — the latter being left immodifial or only slightly modified. Whenever the law of inheritance at corresponding ages prevails. Chap. XVI. Birds — Summary. A99 but not that of sexually-limited transmission, then if the parents vary late in life — and we know that this constantly occurs with om- poultry, and occasionally with other birds— the young wiU 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 imaffected. 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 ; con- sequently 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 pre- served for the ornamentation of the males; the females and the young being left almost imaffected, 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 and degrees, as limited by age, sex, and season. 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, wo 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 inheritance— the females and the young being left comparatively but little modified.'*'^ I am greatly indebted to the birds, and the two following ones kindness of Mr. Sclater for having on mammals. In this way I have looked over these four chapters on been saved from making mistakes 2 K 2 500 Part IL The Desce?it of Man. CHAPTER XVII. Secondary Sexual Characters oe Mammals, The law of battle — Special weapons, confined to the males — Cause of absence of weapons in the female — Weapons common to both sexes, ret primarily acquired by the male — Other uses of such weapons — Their high importance — Greater size of the male — Means of defence — On the preference shewn by either sex in the pairing of quadrupeds. 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.” ‘ 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 breeding-season; and their hides are likewise often covered with scars. Male sperm-whales are very jealous at this season; and in them battles “ they often lock their jaws together, and turn on their “ sides and twist about ;” so that their lower jaws often become distorted.^ 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 coui'se he is not at all answerable for the accuracy of the statements quoted by me from various autho- rities. * See Waterton’s account of two hares fighting, ‘ Zoologist,’ vol. i. 1843, p. 211. On moles. Bell, ‘ Hist, of British Quadrupeds,’ 1st edit. p. 100. On squirrels, Audubon and Bachman, ‘Viviparous Quad- rupeds of N. America,’ 1846, p. 269. On beavers, Mr. A. H. Green, in ‘ Journal of Lin. Soc. Zoolog.’ vol. i. 1869, p. 362. * On the battles of seals, see Capt. C. Abbott in ‘ Proc. Zool. Soc.’ 1868, p. 191; also Mr. B. Brown, ibid. 1868, p. 436 ; also L. Lloyd, ‘ Game Birds of Sweden,’ 1867, p. 412 ; also Pennant. On the sperm-whale, see Mr. J. H. Thompson, in ‘ Proc. Zool. Soc.’ 1867, p. 246. Chap. XVII. Mammals — Law of Battle. 50 1 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.® 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 Chilhngham Park, the descen- dants, degenerated in size but not in courage, of the gigantic Bos jprimigenius. 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 J. B. Sulivan informs me that, when he lived in the Falk- land Islands, he imported a young English stallion, which frequented the hills near Port Wilham 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 flghting. 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 efiScient 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 ca^^se is very different with the males of many other animals. \\e see this in the horns of stags and of certain Idnds of * ^See Scrope (‘ Art of Deer-stalk- wapiti, moose, and rem-deer have i“g> p. 17) on the locking of the been found thus locked together, horns with the Cervus elaphus. Sir A. Smith found at the Cape 01 Richardson, in ‘Fauna Bor. Ameri- Good Hope the skeletons of twc oana,’ 1829, p. 252, says that the gnus in the same condition. S02 The Descent of Man. Paet II. 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 musk-deer, camel, horse, boar, various apes, seals, and the walrus, offer instances. In the females of the walrus the tusks are sometimes quite absent.^ In the male elephant of India and in the male dugong® the upper incisors form offensive weapons. In the male narwhal the left canine alone is developed into the well-known, spirally-twisted, so- called horn, which is sometimes from nine to ten feet in length. It is believed that the males use these horns for fighting to- gether ; for “ an unbroken one can rarely be got. and occasionally “ one may be found with the point of another jammed into the “ broken place.”® 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 omithorhynchus is pro- vided with a remarkable apparatus, namely a spur on the foreleg, closely resembling the poison-fang of a venomous snake ; but ac- cording 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.’^ When the males are provided with weapons which in the females are absent, there can hardly be 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 * Mr. Lamont (‘ Seasons with the Sea-Horses,’ 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, ‘ Proc. Zool. Soc.’ 1868, p. 429. ® Owen, ‘Anatomy of Vertebrate.*:, vol. iii. p. 283. • 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 ‘Proc. 2iuolog. Soc.’ 1871. p. 42. ’’ Owen on the cachalot an*l Omithorhynchus, ibid. vol. iii. pp- 638,641. Harting is quoted by I)r. 2^uteveen in the Dutch translat. ol this work, vol. ii. p. 292. Chap. XVII. Mammals — Law of Battle. 503 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 deei 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 kind of transmission which has prevailed. 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 fuUy 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 fortli their young, and then reappear, generally hornless. In Nova Scotia, however, as I hear from Mr. H. Eeeks, the female some- times 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 foUow 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 durmg this season, which includes the larger part of the time during which she is homed. Nor is it probable that she can have inherited' horns from some ancient pro- genitor of the family of deer, for, from the fact of the females of so many species in aU quarters of the globe not having horns, we may conclude that this was the primordial character of the group." The horns of the reindeer are developed at a most unusually • On the structure and shedding regard to the American variety or of the horns of the reindeer, Hoff- species ; also Major W. Ross King, berg, ‘Amcenitates Acad.’ vol. iv. ‘The Sportsman in Canada,’ 186tf, 1788, p. 149. See Richardson, p. 80. Fauna Bor. Americana,’ p. 241, in 504 l^ART II. The Descent of Man. early age; but what the cause of this may be is not kno-'\Ti. The eftect 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.® 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 (Cerwas canadensis) there is a sharp bony pro- " tuberance in the place of the horn.”*® From these several considerations we may conclude that the possession of fairly well-developed horns by the female reindeer, is due to the male.s having first acquired them as weapons for fighting with other males; and secondarily to their development from some un- known cause at an unusually early age in the males, and theii- consequent transference to both sexes. Turning to the sheath-horned ruminants: with antelopes a graduated series can be formed, beginning with species, the females of which are completely destitute of horns — passing 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 “) — to those which have fairly developed horns, but manifestly smaller and thinner than in the male and sometimes of a different shape,*® — and ending with those in which both sexes have horns of equal size. As with the reindeer, so with antelopes there exists, as pre- viously 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 in inheritance. It accords with this ° Isidore Geoffrey St. Hilaii-e, ‘ Essais de Zoolog. Gdn4rale,’ 1841, p. 513. Other masculine characters, besides the horns, are sometimes similarly transferi'ed to the female ; thus Mr. Boner, in speaking of an old female chamois (‘ Chamois Hunting in the Mountains of Ba- varia,’ 1860, 2nd edit. p. 363), says, “ not only was the head very male- “ looking, but along the back there “ was a ridge of long hair, usually “ to be found only in bucks.” 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 Acad, of Nat. Sciences,’ May, 1868, p. 9. I am indebted to Dr. Canfield, for this information, see also his paper in ‘ Proc. Zoolog. Soc.,’ 1866, p. 105. For instance the horns of the female Ant. anchore resemble those of a distinct species, viz. the Ant- dorcas var. Corine, see Desmarest, ‘ IMammalogie,’ p. 455. Chap. XVII. Mammals — Law of Battle. 50s 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 nonnally destitute of horns, Mr. Blyth has seen no less than three females thus furnished ; and there was no reason to suppose that they were old or diseased. In all the wild species of goats and sheep the horns are larger in the male than in the female, and axe sometimes quite absent in the latter.** In several domestic breeds of these two animals, the males alone are furrdshed with horns ; and in some breeds, for instance, in the sheep of North Wales, though both sexes are properly homed, the ewes are very liable to be hornless. I have been iuformed 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 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 con- siderably 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 to look at the horns as properly of masculine origin. With the adult musk-ox (^Ovibos moschatus) the horns of the male are larger than those of the female, and in the latter the bases do not touch.** 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 cow-banteng (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.”** Dr. Forsyth Major also informs me that a fossil skull, beheved to be that of the female Bos etruscus, has been found in the 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 m some other species of rhinoceros they Gray, ‘ Catalogue Mamm. Brit, ricana,’ p. 278. Mils.’ part ui. 18.'i2, p. 160. < Land and Water,’ 1867, p. Kichardson, ‘ Fauna Bor. A me- 346. ^ The Descent of Man. Part II. So6 are said to be shorter in the female.’“ 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 conquor other males, and have been transferred more or less completely to the female. The effects of castration deseiwo notice, as throwing light on this same point. Stags after the operation never renew then- horns. The male reindeer, however, must be excepted, as after castration he does renew them. This fact, as well as the pos- session of horns' by both sexes, seems at first to prove that the horns in this species do not constitute a sexual character 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 like- wise the case ■with other animals. Merino rams have large horns, whilst the ewes “ generally speakmg 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.” “ On the Guinea coast there is a breed in which the females never bear horns, and, as Mr. Winwood Eeade informs me, the rams after castration are quite desti- tute 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 re- semble them. The Antilope hezoartica offers a somewhat ana- logous 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 '• Sir Andrew Smith, * Zoology of S. Africa,’ pi. six. Owen, ‘ Ana- tomy of Vertebrates,’ vol. iii. p. 624. This is the conclusion of Seidlitz, ‘ Dio Darwinscho Theorie,’ 1871, p. 47. I am much obliged to Prof. Victor Cai-ns, for having made en- quiries for me in Saxony on this subject. H. von Nathusius (‘ Vieh- zucht,’ 1872, p. 64) says that the horns of sheep castrated at an early period, either altogether disappc.ar or remain as mere rudiments ; but I do not know whether he refers to merinos or to ordinary breeds. Chap. XVII. Mammals — Law of Battle. 507 condition of the horns in some early progenitor of each species. But why castration should lead to the reappearance of an early oondition of the horns cannot he 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 long-lost characters;^® so here, the disturbance in the constitution of the individual, resulting from castration, produces the same effect. 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 well- developed 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.”®® The African elephant is undoubtedly distinct, and the female has large well- developed tusks, though not so large as those of the male. These differences in the tusks of the several races and species of elephants — ^the great variability of the horns of deer, as notably in the wild reindeer — the occasional presence of horns in the female Antilope hezoartica, and their frequent absence in the female of Antilocapra americana — the presence of two tusks in some few male narwhals — the complete absence of tusks in some female walruses — are aU instances of the extreme variability of secondary sexual characters, and of their liability to differ in closely-allied forms. Although tusks and horns appear in aU 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 fari- naceous 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 bo occasionally put, is that observed by Captain Hutton®^ with I have given various experi- Sir J. Emerson Tennent, ‘ Cey- ments and other evidence proving Ion,’ 1859, vol. ii. p. 274. For that this is the case, in my ‘Varia- Malacca, ‘Journal of Indian Archi- tion of Animals and Plants under pclago,’ vol. iv. p. 357. Domestication,’ vol. ii., 1868, pp. 39 ‘ Calcutta Journal of Nat. Hist. -47. Tol. ii. 1843, p. 526. The Descent of Man. Faet IJ. 50a the wild goat {Capra xgagrus) of the Himalayas and, as it is also said, with the ibex, namely, that when the male accidentally falls f)-om 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 disposition she does not need this strange kind of shield so much. 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 power- ful man knocked over like a child. Goats and certain species of sheep, for instance the Ovis cycloceros of Afghanistan,^ 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 scimitar-shaped “ horn, as with a sabre. When the 0. 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 thirty-nine 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 hom-s, he gives a tremendous blow with his convex forehead, and then tramples on his fallen enemy with his knees — an instinct which the common bull does not possess.^® Hence a dog who pins a buffalo by the nose is immediately crushed. We must, however, remember that the Italian bufialo has been long domesticated, and it is by no means certain that the wild parent-form had similar horns. Mr. Bartlett informs me that when a female Cape buffalo {Buhalus 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 haii’-covered horns, which are rather longer in the male than in the female, in a curious maimer ; for, with his long neck, he swings his head to either side, almost upside down, with such Mr. Blyth, in * Land and goats see the ‘ Field,’ 1869, p. 150. Water,’ March, 1867, p. 134, on “ M. E. M. Bailly, ‘Sur I’uiuige the authority of Capt. Hutton and dos Comes,’ &c., ‘Annal. des 8c, others. For the wild Pembrokeshire Nat.’ tom. ii. 1824, p. 369. Chap. XVII. Mammals — Law of Battle. 509 force, that I have seen a hard plank deeply indented by a single blow. With antelopes it is sometimes difficult to imagine how they can possibly use their curiously-shaped horns ; thus the spring- boc {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 slightly-curved horns of the Fig. 63. Oryx lencoryx, male (from the Knowsley Menagerie) Oryx leucaryx (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 ill-fitted for fighting ; but Mr. Bartlett informs me that when two of these animals prepare for battle, they kneel down, with their heads 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 com- batants 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 horns with effect even against a lion ; yet from being forced to place his head between the fore-legs in order to bring the points of the 510 The Descent of Man. Paut II, 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 acquir^ moderately long horns, directed a little backwards, he would be compelled, in his battles with rival males, to bend his head somewhat inwards or down- wards, as is now done by certain stags ; and it is not improbable that ho 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, imtil 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 Sh Philip Egerton’s museum there is a horn of the red-deer {Ce>'vus elaphus), thirty inches in length, with “not “ fewer than fifteen snags or branches;” and at Moritzbm-g there is still preserved a pair of antlers of a red-deer, shot in 1699 by Frederick I., one of which bears the astonishing number of thirty-three branches and the other twenty-seven, making altogether sixty branches. Eichardson figures a pair of antlers of the wild reindeer with twenty-nine points.“^ 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, “ M. BaiUy 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 red-deer, 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 gi'eat protection to the forehead, and their points are likewise On the horns of red-deer, 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. Hon. J. 'D. Caton Ottawa Acad, of Nat. Science,’ May, 1868, p. 9), says that the American deer fight with their fore-feet, after “ the question of superiority ha.s “ been once settled and acknowledged “ in the herd.” Bailly, ‘Sur I’usage des Comes,’ ‘Annalcs des Sc. Nat.’ tom. ii. 1824, p. 371. Chap. XVIL Mammals — Law of Battle. 511 used in attack. Sir PhUip Egerton also informs me both as to red-deer and fallow-deer 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 aa-e used as weapons of offence; when a man was attacked by a wapiti deer (Gervus 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 plimge.” In tins position the ends of the.homs 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.^® 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 conclu- sion. 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 them graceful double curvature, (fig. 61), are ornamental in omr 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 of this behef. An interesting case has lately been pubhshed, 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 says, that he has See a most interesting account ‘ The American Naturalist,’ in the Appendix to Hon. J. D. Dec. 1869, p. 552. Catou’s paper, as above quoted. 512 The Descent of Man. Paut II. liunted for the last twenty-one years in the Adirondacks, where the Ctrvus virginianus abounds. About fourteen years ago he first heard of spike-horn 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 spike-horn “ differs greatly from the common antler of the C. virginianus. Fig. 64. Strppslceros Kudu (from Sir Andrew Smith’s ‘ Zoologj' of South Africa " 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 Cjiap. XVII. Mam^nals — Law of Battle. 513 “ 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 bucte when “ armed with their cumbrous antlers), the spike-horn is a more “ effective weapon than the common antler. With this advantage “ the spike-horn bucks are gaining upon the common bucks, and “ may, in time, entirely supersede them in the Adirondacks. “ Undoubtedly, the first spike-horn buck was merely an acci- “ dental freak of nature. But his spike-horns 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, tiU 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 parent-form 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 prong-horned 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 leucwyx, 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 horns, if he fought only with his proper rivals. 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. The walrus, though having so short a neck and so unwieldy a body, “can strike either upwards, or downwards, or sideways, with “ equal dexterity.”^* 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 ho is able to fiing a tiger to a groat distance — it is said to even thirty feet; when they are short and turned downwards he endeavours suddenly to pin the P.dlas, ‘ Spicilegia Zoologica,’ ^ Lament, ‘ Seasons with the Sea- tasc. xiii. 1779, p. 18. Horses,’ 1861, p. 141. 514 The Desce7tt of Man. Part II. tiger to the ground and, in consequence, is dangerous to the rider, who is liable to be jerked off the howdah.^ Very few male quadrupeds possess weapons of two distinct kinds specially adapted for fighting with rival males. The male muntjac-deer (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 musk-deer, 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 canine-shaped incisors in their upper jaws.®' 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 arc of any service in their battles. In Antilo’pe 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.®® Stalhons 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 staUions 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 pro- genitor of the species was provided with efficient canines, which have been partially transfen-ed 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 weapons. Tusks and horns are manifestly of high importance to their See also Corse (‘ Philosoph. Transact.’ 1799, p. 212) on the manner in which the short-tusked Mooknah variety attacks other ele- phants. Owen, ‘Anatomy of Verte- brates,’ vol. iii. p. 349. ’2 See Riippell (in ‘ Proc. Zoolog Soc.’ Jan. 12, 1836, p. 3) on tho canines in deer and antelopes, with r. note by Mr. Martin on a female American deer. See also Falconer (‘ PaliEont. Memoirs and Notes," vol. i. 1868, p. 576) on canines in an adult female deer. In old males of the musk-deer 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. Chap. XVII. Mammals — Greater Size of Male. 515 possessors, for their development consumes mucli organised matter. A single tusk of the Asiatic elephant— one of the extinct woolly species— and 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.®^ 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 pounds— the 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 wiU 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.” The tips of the horns of the great Msh elk were actually eight feet apart ! Whilst the horns are covered with velvet, which lasts with the red-deer 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.® 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 rival males. 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 (Oallor- hinus urmius), a full-grown female weighing less than one-sixth of a full-grown male.® Dr. Gill remarks that it is with the Emerson Tennent, ‘Ceylon,’ 1859, vol. ii. p. 275; Owen, ‘Bri- tish Fossil Mammals,’ 1846, p. 245. Kichardson, ‘ Fauna Bor. Ame- ricana,’ on the moose, Akes palmata, pp. 236, 237 ; on the expanse of the home, ‘Land and W.ater,’ 1869, p. 143. See also Owen, ‘ British Fossil Mammals,’ on the Irish elk, pp. 447, 455. ‘ Forest Creatures,’ by C. Boner, 1861, p. 60. See the very interesting paper by Mr. J. A. Allen in ‘ Bull. Mas. 2 L 2 5i6 The Descent of Man. ?AET II, polygamous seals, the males of which are well known to fight savagely together, that the sexes differ much in size ; the mono- gamous 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 right-whales do not fight together, and they are not larger, but rather smaller, than their females ; on the other hand, male sperm-whales, fight much together, and their bodies are “ often “ found scarred with the imprint of their rival’s teeth,” aud they are double the size of the females. The greater strength of the male, as Hunter long ago remarked,®’ is invariably displayed in those parts of the body which are brought into action in fighting with rival males — for 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 selec- tion, 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 coiu'age, whether due to mere variability or to the effects of use, by the accumulation of which male quadrupeds have acquii-ed 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 auy 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 witii 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 83 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.®® Mr. Cupples Comp. Zoolog. of Cambridge, United States,’ vol. ii. No. 1, p. 82. The weights were ascertained by a care- ful observer, Capt. Bryant. Dr. Gill in ‘The American Naturalist,’ Jan. 1871, Prof. Shaler on the relative size of the sexes of whales, ‘American Naturalist,’ Jan. 1878. ‘ Animal Economy,’ p. 45. See also Richardson’s ‘ Manual on the Dog,’ p. 59. Much valuable information on the Scottish deer- hound is given by Mr. McNeill, who first called .attention to the inequality in size between the sexes, in Scrope’s ‘ Art of Deer Stalking.’ Chap. XVII. Mammals — Greater Size of Male. 517 coucludes 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. Guppies 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 foui’teen ounces. Mr. Wright of Yeldersley House, in a letter to Mr. Guppies, says : “ 1 have taken notes on “ the sizes and weights of puppies of many litters, and as far a.s “ my experience goes, dog-puppies 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 bitch-puppy will occasionally be larger than any “ of the dogs, but they are invariably beaten by them later.” Mr. McNeill, of Golonsay, concludes that “the males do not “ attain their full growth till over two years old, though the “ females attain it sooner.” According to Mr. Guppies’ expe- rience, male dogs go on growing in stature till they are from twelve to eighteen months old, and in weight till from eighteen to twenty-four 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 suflBicient strength and weight to puU down a full-grown deer. From the names used in old legends, it appears, as I hear from Mr. Guppies, 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 deer-hound may probably be accounted for, 1 hope that Mr. Guppies will keep account and history of this famous to his intention of publishing a full breed. 5 1 8 The Descent of Man. Part h. 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 de- fending 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 spe- cially modified for defence. With boars in the prime of life (see 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 up- wards over the snout, that they can no longer bo 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 years.®® In the full-grown male Baburisa 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 Brehm, ‘Thierleben,’ B. u. s. 729-732. Fig. 65. Head of Common wild boar, in prime of life Qfrom Brehm). Chai>. XVII. Mammals — Means of Defence. 5^9 laterally, would serve as an excellent guard , and hence, perhaps, it is that in old animals they “ are generally broken olf, as if by “ fightiijg.”'*^ Here, then, we have the curious case of the upper tusks of the Babirusa regularly assuming during the prime of hfe, a structirre 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, nearly the same form, and then serve in hke manner solely for defence. 1' y- B6. Skull ot the Babirusa Pig (from Wallace’s ‘ Malay Archioelago In the wart-hog {Phacochoerus cBthiopicus, 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 frorn their shortness it seems hardly possible that they can be used as weapons of attack. They must, however, greatly rtrengthen those in the upper jaw, from being ground so as to fit closely against their bases. Neither the upper nor the lower « See Mr. Wallace’s interesting account of this auimai, ‘The Malay Archipelago,’ 1869, vol. i. p. 435. ^ 520 The Descent of Man. Part IL tusks appear to have been specially modified to act as guards, though no doubt they are to a certain extent used for this pur- pose. But the wart-hog 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 directly face to face. Fig. 67. Head of female .^Ethiopian wart-hog, 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, 1 was under the impression that it repre- sented the male. Lastly, the African river-hog (Potomochoenis penicillatus) has a hard cartilaginous knob on each side of the face beneath the eyes, which answers to the flexible pad of the wart-hog ; 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 wart-hog. 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 purpose of the above-described projections and excrescences, that these were covered with blood, and were scored and abraded in an extra- ordinary manner. Although the males of so many members of tho pig family are CHiP. XVII. Mammals — Means of Defence. 521 provided with weapons, and as we have just seen with means ol defence, these weapons seem to have been acquii’ed within a rather late geological period. Dr. Forsyth Major specifies^ several miocene species, in none of which do the tusks appear to have been largely developed in the males ; and Prof. Eiitimeyer was formerly struck with this same fact. The mane of the lion forms a good defence against the attacks of rival lions, the one danger to which he is hable; for the males, as Sir A. Smith informs me, engage in terrible battles, and a young hon 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.” The broad ruff round the throat and chin of the Canadian lynx (Fehs 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)*^ 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 Zoo- logical 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 hon, whilst in the young of both sexes and in the female the mane is almost absent. 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 behef. 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 ‘ Atti della Soc. Italiana di Sc. Dr. Murie, on Otaria, ‘ Proc. Nat.’ 1873, vol. xv. fasc. iv. Zoolog. Soc.’ 1869, p. 109. Mr. J. ‘The Times,’ Nov. 10th, 1857. A. Allen, in the paper above quoted In regard to the Canada lynx, see (p. 75), doubts whether the hair, Audnbon and Bachman, ‘ Quad- which is longer on the neck in the rupeds of N. Amenca,’ 1846, p. male than in the female, deserves to 139. be called a mane. 522 The Descent of Man. Paet ir. " endeavour to seize one anotlicr 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 ( Ctrvus 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. Choice in Pairing hy either Sex of Quadrupeds. — Before de- scribing 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 imiuession amongst breeders seems to be that the male accepts any female ; and this owing to his eager- ness, 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 red-deer, as I am informed by Sir Phihp Egerton and others.^^ It is searcely 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 Bourtship of one of the eared seals (Callorhinus ursinus) are ** Mr. Boner, in his excellent description of the habits of the red- doer in Germany Forest Creatures,’ 1861, p. 81) says, “ while the stag “ is defending his rights against one “ intruder, another in.vades the “ sanctuary of his harem, and car- “ ries off trophy after trophy.” Ex- actly the same thing occurs with seals, see Mr. J. A. Allen, ibid, p 100. Chap XTII. Mammals — Choice in Pairing'. 523 given 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, calhng out and “ listening as if for a famihar 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 takiog 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 pui'sue 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 domesti- cated 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 Ml. J. A. Allen in ‘Bull. Mus, Comp. Zoolog. of Cambridge, United States,’ vol. ii. Ho. 1, p. 99. ^ 524 The Descent of Man. Paet II. strongly attracted by males of a largo size. The well-known veterinary Blaine states'*’ that his own female pug 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 similiar and trustworthy accounts have been given me in regard to a female retriever and a spaniel, both of which became enamoured with terrier- dogs. Mr. Guppies 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 aclmowledge the courtship of any other dog, and to the regret of her owner never bore puppies. Mr. Guppies also states, that in 1868, a female deerhound in his kennel thrice pro- duced 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 hfe. Mr. Guppies 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 Yoldersley House, a great breeder of dogs, infoiTus me that he has known some instances ; he cites the case of one of his O'wn deerhounds, who would not take any notice of a particular female mastiff, so that another deerhound had to be employed. It would be supei-fluous 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 prefer- ence for each other. Finally, Mr. Guppies, 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 race-horses in the world, informs mo that stallions ore so frequently capricious in their choice, rejecting one mare and ‘ Do^s : their Mnnagemcnt,’ by Quoted by Alex. Walker ' Ou E. Mayhew, M.R.C.V.S., 2nd edit. Intermarriage,* 1838, p. 276; ^e• 1864, pp. 187-192. also p. 244. Chap. XVIII. Mammals — Choice in Pairing. 525 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 race-horse 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 quotes various statements from Fi-ench autho- rities, and remarks, “ On voit des 4talons 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. Eeeks assures me that a famous short-horn bull belonging to his father “ invariably refused to be matched with a black cow.” Hofifberg, in describing the domesticated reindeer of Lapland says, “FcemuiEe majores et fortiores mares prae cseteris admittunt, “ ad eos confugiunt, a junioribus agitatse, qui hos in fugam “ conjiciunt.”^^ A clergyman, who has bred many pigs, asserts that sows often reject one boar and immediately accept another. From these facts there can be no doiibt that, with most of our domesticated quadrupeds, strong individual antipathies and pre- ferences are frequently exhibited, and much more commonly by the female than by the male. This being the case, it is impro- bable that the unions of quadrupeds in a state of natui-e 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 or never discover with certainty. CHAPTER XVIII. Seoondaet Sexual Chabaotees op Mammals — continued. Voice — Remarkable sexual peculiarities in seals — Odour — Development of the hair — Colour of the hair and skin — Anomalous case of the female being more ornamented than the male— Colour and ornaments due to sexual selection— Colour acquired for the sake of protection — Colour, though common to both sexes, often due to sexual selection — On the disappearance of spots and stripes in adult quadrupeds — On the colours and ornaments of the Quadrumana — Summary. 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 ■i Ta* tom. <» ‘ Amoenitates Acad.’ vol. iv, u. idjO, p. 29b. 1788, p. 160. 526 The Descent of Man. Pabt 1L 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 rutting-season than at any other time ; and some, as the giraffe and porcupine,' are said to be completely mute excepting at this season. As the throats (i.e. the larynx and thyroid bodies of stags periodically become enlarged at the beginning of the breeding-season, it might he thought that their powerful voices must be somehow of high importance to them ; but this is very doubtful. From infonnation 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 com- mencement of the breeding-season, 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 imder any strong emotion, as when enraged and pre- paring 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, imless at the same time the stronger’, better-armed, and more courageous, would not gain any advan- tage over their rivals. 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 tliat 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,® as is well known to the hunters who in wild countries * Owen, ‘ Anntomy of Verte- ® See, for instance. Major W. brates,’ vol. iii. p. 585. Ross King (‘ The Sportsman in ' Ibid. p. 595. Canada ’ 18G6, p. 53, 131) on the CuAP. XVIII. Mammals — Vocal Organs. 527 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 ot this view. As the case stands, the loud voice of the stag during the breeding-season 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 in- herited effect on the vocal organs of the stag, as well as of other male animals? This appears to me, in our present state ot knowledge, the most probable view. The voice of the adult male gorilla is tremendous, and he is furnished with a laryngeal sack, as is the adult male orang."* The gibbons rank among the noisiest of monkeys, and the Sumatra species (ffylobates syndactylus) is also furnished with an air sack ; but Mr. Blyth, who has had opportunities for observa- tion, 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.® Another gibbon, the E. agilis, is re- markable, from having the power of giving a complete and correct octave of musical notes,® which we may reasonably sus- pect 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 one-third 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 con- cert, and often continue it during many hours, the females, sometimes joining in with their less powerful voices. An excellent observer, Eengger,’ 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 them rivals and charm the females — or whether the vocal organs have been strengthened habits of the moose and wild rein- • C. L. Martin, ‘ General Intro- duction to the Nat. Hist, of Mamm. ^ Owen, ‘ Anatomy of Vcrte- Animals,’ 1841, p. 431. brates.’ vol. iii. p. 600. 7 ‘ Naturgeschichte der SUnpe- * Mr. Green, in ‘Journal of Linn, thiere von Paraguay,’ 1830, s. 15, Soc.’ vol. X. Zoology, 1869, p. 362. 21. 528 The Descent of Man. Part II. and enlarged through the inherited effects of long-continued use without any particular good being thus gained — I will not pretend to say ; but the former view, at least in the case of the Hylohates agilis, seems the most probable. I may here mention two very curious sexual peculiarities occurring in seals, becaiise they have been supposed by some writers to affect the voice. The nose of the male sea-elephant {Macrorhinus prohoscideus) becomes greatly elongated during the breeding-season, 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 behoved 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 galhnaceous birds whilst courting the females. In another alhed kind of seal, the bladder- nose (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; it 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 mritated 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. E. 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. Lament who killed GOO of these animals, the hood is rudimentary in the females, and it is not developed in the males during youth.® Odour. — With some animals, as with the notorious skunk of America, the overwhelming odour which they emit appears to serve exclusively as a defence. With shrew-mice (Sorex) both sexes possess abdominal scent-glands, 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 breeding-season. In “ On the sea-elephant, see an 1824, p. 94. Pennant has also article by Lesson, in ‘Diet. Class, collected information from the Hist. NaL’ tom. liii. p. 418. For sealers on this animal. The fullest the Cystophora or Stemmatopus, account is given by Mr. Brown, in see Dr. Dekay, ‘ Annals of Lyceum ‘ Proc. Zoolog. Soc.’ 1868, p. 435. of Nat. Hist. New York,’ voL i. Ohap. XVIII. Mammals — Odours emitied. 539 many other quadrupeds the glands are of the same size in both sexes,® 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 rutting-season. 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 hats have glands and protrudable sacks situated in various parts ; and it is believed that these are odoriferous. 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 fibrst 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.’° Besides the general odour, permeating the whole body of certain rumi- nants (for instance, jBos moschatus) in the breeding-season, many deer, antelopes, sheep, and goats, possess odoriferous glands in various situations, more especially on their faces. The so-called tear-sacks, or suborbital pits, come under this head. These glands secrete a semi-fluid 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.”*^ According to Desmarest they are altogether absent in the female of Antilope suigutturosa. 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 musk-deer {Moschus moschiferus), a naked space round the tail is bedewed with an * As with the castoreum of the beaver, see Mr. L H. Morgau’s most interesting work, ‘ The Ame- rican Beaver,’ 1868, p. 300. Pallas (‘Spic. Zoolog.’ fasc. viii. 1779, p. 23) has well discussed the odorifer- ous glands of mammals. Owen (‘Anat. of Vertebrates,’ vol. iii. p. 634) also gives an account of these glands, including those of the ele- phant, and (p. 763) those of shrew- mice. On Bats, Mr. Dobson in ‘ Proc. Zoolog. 80c.’ 1873, p. 241. ** Rengger, ‘ Natnrgeschichte der Siiugethiere von Paraguay,’ 1830, s. 355. This observer also gives some curious particulars in regal'd to the odour. u Owen, ‘Anatomy of Verte- brates,’ vol. iii. p. 632. See, also Dr. Murie’s observations on these glands in the ‘ Proc. Zoolog. Soc.’ 1870, p. 340. Desmarest, On the Antilope eubgutturosa, ‘ Mamma- logie,’ 1820, p. 455. Part II. 53*^ The Descent of Man. 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 scent-organ. It is a singular fact that the matter secreted by this latter gland does not, according to Pallas, change in con- sistence, or increase in quantity, during the rutting-season ; 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.*^ 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 tbe females from a distance to the males. Active and long-continued 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 develop- ment 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 and odours. Development of the Hair. — 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 hkely to be injm-ed ; 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^^ (see fig. 70, p. 514) and Portax picta, may be given as Pallas, ‘ Spicilegia Zoolog.’ fasc. ’• Dr. Gray, ‘Gleanings from the xiii. 1799, p. 24; Desmoulins, ‘ Diet. Menagerie at Knewsley,’ pi. 28. Class, d’llist. Na*.’ tom. iii. p. 586. Chap. XVIII. Mammals — Development of Hair. 531 instances. When stags, and the males of the wild goat, are em-aged or terrified, these crests stand erect but it cannot he supposed that they have been developed merely for the sake of exciting fear in their enemies. One of the above-named an- telopes, the Portax picta, has a large well-defined brush of black hail- 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 sheep-family, the fore-legs 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 beheve 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. 1'hus the bull alone has curled hair on the forehead.^® In three closely-aUied sub-genera of the goat family, only the males possess beards, sometimes of large size ; in two other sub-genera 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 it is so small at other times that it may be called rudimentary.^® 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,” and, as we have seen, with the manes of some species of baboons. But with most kinds of monkeys the various tufts of ham about the face and head are alike in both sexes. The males of various members of the ox family (Bovidae), and of certain antelopes, are furnished with a dewlap, or great fold of sldn 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 ol certain male goats, or the dewlap of the buU, or the crests ol hair along the backs of certain male antelopes, are of any use to them in them ordinary habits. It is possible that the im- mense 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 “ Judge Caton on 'the Wapili, ‘ Transact. Ottawa Acad. Nat. Sciences,’ 1868, pp. 36, 40 ; Blyth, ‘Land and Water,’ on Capra xga- gms, 1867, p. 37. ‘Hunter’s Essays and Observ.v tions,’ edited by Owen, 1861, vol. i. p. 236 See Dr. Gray’s ‘ Cat. of Mam- malia in British Museum,’ part iii. 1852, p. 144. Rengger, ‘ Saugethiere,’ &o. s. 14; Desmarest, ‘ Mammalogio,’ p. 2 M 2 532 Part IJ. The Descejit of Man. 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 variabihty in the male ? It cannot bo denied that this is possible ; for in many domesticated quad- rupeds, certain characters, apparently not derived through re- version 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 zebu-cattle of India, the tail of fat-tailed S rams, the arched outhne of the forehead in the males of several 1 breeds of sheep, and, lastly, the mane, the long hairs on the A hind-legs, and the dewlap of the male of the Berbura goat.’* The 1 mane, which occurs only in the rams of an African breed ofj ] 'l See the chapters on these ‘ Variation of Animals under Dome.s-^ , several animals in vol. i. of my tication ; ’ also vol. ii. p. 73 ; .also U Chap. X7III. Mammals — Ornamental Colours. 533 sheep, is a true secondary sexual character, for, as I hear from Mr. Win wood Ecade, it is not developed if the animal he castrated. Although we ought to he extremely cautious, as shewn in my work on 'Variation imder Domestication,’ in concluding that any character, even with animals kept by semi-civilised 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 Berhm-a male-goat with his mane, dewlap, &c., 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 vdth sexually-limited inheritance. 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 fore-legs 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 acquh-ed at some period for a special pm-pose. With those antelopes in which the adult male is more strongly-coloured 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 naturahsts. If this be correct, there can be little doubt that they were gained or at least modified through sexual selection ; but how far the same view may be extended to other mammals is doubtful. Colour of the Hair and of the Naked Skin. — 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.”'® In the Didelphis opossum of Cayenne chap. XI. on the practice of selection logue,’ ibid. p. 157. by semi-civillsed people. For the OsjjAra.'iterru/us, Gould, ‘Mam- herbura goat, .see Dr. Gray, ‘ Cata- mals of Australia,’ 1863, vol. ii, 534 The Descent of Mem. Paut II. the female is said to be a little more red than the male. Of the Eodents 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.”'^® 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.®* Ml’. Dobson also remarks, with respect to these animals : " Dif- “ ferences, 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 horn being orna- mental. In one genus of sloths, it is now established, as Dr. Gray states, "that the males are ornamented differently from the " females — that 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 pure white. The females on “ the contrary, are destitute of this mark.” The terrestrial Carnivora and Insectivora rarely exhibit sexual differences of any kind, including colour. The ocelot {Felis pnrdalis), 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.”®® 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 On the Didelphis, Desmarest, ‘ Mammalogie,’ p. 256. ‘ Annals and Mag. of Nat. Hist.’ Nov. 1867, p. 325. On the Mus minutus, Desmarest, ‘ Mammalogie,’ p. 304. ** J. A. Allen, in ‘ Bulletin of Mu£. Comp. Zoolog. of C.ambridge, United States,’ 1869, p. 207. Mr. Dobson on se-rual characters in the Chiroptera, ‘ Proc. Zoolog. Soc.’ 1873, p. 241. Dr. Gray on Sloths, ibid. 1871, p. 436. Desmarest, ‘ Mammalogie,’ 1820, p. 220. On Felis mitis, Rengger, ibid. s. 194. Chap. XVIII. Mammals — Ornanmiial Colottrs. 535 female, who acquires her adult tints earlier in life than the male, is dark-grey above, the young of both sexes being of a deep chocolate colour. The male of the northern Plioca groenlandica is tawny grey, with a curious saddle-shaped dark mark on the back; the female is much smaller, and has a very different appearance, being “ dull white or yellowish straw-colour, 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.” “ With Euminants 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 ndlghau (Portax picta) is bluish-gi-ey 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 aU 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 breeding-season. 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^* that neither the red summer- coat nor the blue winter-coat of the Virginian deer is at all affected by emasculation. With most or all of the highly-orna- mented species of Tragelaphus the males are darker than the hornless females, and their crests of hair are more fuUy 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.^® In the Indian black-buck (A. lezoartica), which belongs to another tribe of antelopes, the male is very dark, almost black ; whilst the hornless female is fawn-coloured. We meet in this Dr. Murie on the Otaria, ‘ Proc. Zool. Soc.’ 1869, p. 108. Mr. R. Brown, on the P. groenlandica, ibid. 1868, p. 417. See also on the colours of seals, Desmarest, ibid. p. 243, 249. JudgeCaton, in ‘Trans. Ottawa Acad, of Nat. Sciences,’ 1868, p. 4. Dr. Gray, ‘ Cat. of Mamm. in Brit. Mns.’ part iii. 1852, pp. 134— 142 ; also Dr. Gray, ‘ Gleanings from the Menagerie of Knowsley,’ in which there is a splendid drawing of the Oroas derbianus : see the text on Tragelaphus. For the Ca])e eland (Oreas cannd), see Andrew Smith, ‘ Zoology of S. Africa,’ pi. 41 and 42. There are also many of these antelopes in the Zoologioal Gardens. 536 The Descent of Man. Part II, species, as Mr. Blyth informs me, with an exactly similar series of facts, as in the Fortax pir.ta, namely, in the male periodically changing colour during the breeding-season, 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. sing-sing 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.” Other analogous cases could be added. 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, beUy, 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 pai-k three races of the Virginian deer, which differ shghtly in colour, but the differences are almost ex- clusively confined to the blue winter or breeding coat ; so that this case may be compared with those given in a previous chapter of closely-alhed or representative species of birds, which differ fi'om each other only in their breeding plumage.” 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 blackish-brown line on the breast, which are characteristic of tho adult males.“® Lastly, as I am informed by Mr. Blyth, the ■“ On the Ant. niger, see ‘Proo. Zool. Soc.’ 1850, p. 133. With re- spect to an allied species, in which there is an equal se.’tual difference in colour, see Sir S. Baker, ‘The Albert Nyanza,’ 1866, vol. ii. p. 327. For the A. sing-sing, Gray, ‘ Cat. B. Mus.’ p. 100. Desmarest, ‘ Mammalogie,’ p. 468, on the A. caama. Andrew Smith, ‘Zoology of S. Aft 'ca,’ on the Gnu. ‘ Ottawa Academy of Sciences,' May, 21, 1868, pp. 3, 5. ““ S. Muller, on the Banteng, ‘Zoog. Indischen Archipel.’ 1839- 1844, tab. 35 ; see also Raflles, as quoted by Mr. Blyth, in ‘ Land and Water,’ 1867, p. 476. On goats. Dr. Gray, ‘Cat. Brit. Mus.’ p. 146 ; Desmai’est, ‘ Mammalogie,’ p. 482. On the Cervus paludosus, Rengger, ibid. s. 345. Chap. XVIII. Mammals — Ornamental Coloun. 537 mature male of the beautifully coloured and spotted axis deer is considerably darker than the female ; and this hue the castrated male never acquires. The last Order which we need consider is that of the Primates. The male of the Lemur macaco is generally coal-black, whilst the female is brown.-® Of the Quadrumana of the New World, the females and young of Mycetes caraya are greyish-yellow and like each other ; in the second year the young male becomes reddish- brown ; in the third, black, excepting the stomach, which, how- ever, becomes quite black in the fourth or fifth year. There is also a strongly-marked 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 brownish-black above and Light rusty-red beneath, the adult males being black. The ruff of hair round the face of Aides 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 whity-brown to a dark tint mixed with black, but are never wholly black.®® 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 Cephas') the only difference between the sexes is that the tail of the male is chesnut and that of the female grey; but Mr. Bartlett informs me that all the hues becomes more pronounced in the male when adult, whilst in the female they remain as they were dui'ing youth. Ac- cording to the coloured figures given by Solomon Muller, the male of Semnopithecus chrysomelas is nearly blaek, the female being pale brown. In the Cercopithecus cynosurus and griseo- viridis 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 the liinder part of the body, which is vivid red. Lastly, in the baboon family, the adult male of Cynocephalus hamadryas differs from the female not only by his immense Sfilater, ‘ Proc. Zool. Soc.’ 1866, p. 1. Ihe same fact has also been fully ascertained by MM. Pollen and van Dam. See, also, Dr. Gray in ‘ Annals and Mag. of Nat. Ilist.’ May 1871, p. 340. “ On Mycetes, Rcngger, ibid. s. 14 ; and Brehm, ‘ Illustrii-tes Thier- leben,’ B. i. s. 96, 107. On Ateles, Desmarest, ‘ Mammalogie,’ p. 75. On Hylobates, Blyth, ‘Land .and Water,’ 1867, p. 135. On the Sem- nopithecus, S. Muller, ‘Zoog. In- dischen Archipel.’ tab. x. 538 The Descent of Man. Part II. mane, biit slightly in the colour of the hair and of the naked callosities. In the drill (C. leucopheeus) the females and young are much paler-coloured, 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 (O'. 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 Fig. 69. Head of male Mandrill (from GervaiB, ‘Hist. Nat. des Ifammifercs’). 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 egalernent “ eolores du rouge le plus vif, avee un melange de bleu qui ne Chap. XVlIl. Mammals — Ornamental Colours. 539 “ manque reellement pas d’elegance.”^* Wlieii the animal is excited all the naked parts become much more vividly tinted. Several authors have used the strongest expressions in de- scribing these resplendent colours, which they compare with those of the most brilliant birds. Another remarkable pecu- liarity is that when the great canine teeth are fully developed, immense protuberances of bone are formed on each cheek, which aie deeply furrowed longitudinally, and the naked skin over them is brilliantly-coloured, as just described. (Fig. 69.) In the adult females and in the young of both sexes these protuber- ances 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 regular intervals of time becomes tinted with red. 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 Ehesus 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 occa- sionally, or dui'ing 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 ridges, he follows the common rule of the male excelling the female. I have now given all the cases known to mo 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 TOthout the aid of selection. We have instances of this with our domesticated animals, as in the males of certain cats being rusty-red, whilst the females are tortoise-shell coloured. Analo- gous cases occur in nature : Mr. Bartlett has seen many black varieties of the jaguar, leopard, vulpine phalanger, and wombat; Gervais, ‘ Hist. Nat. des Mam- Desmarest, ‘ Mammalogie,’ p. 70. miftres,’ 1854, p. 103. Figures are Geoifroy St.-Hilaire and F. Cuvier, given of the skull of the male. Also ‘ Hist. Nat. des Mamm.’ 1824, tom. i. 540 The Dcscetit of Man. Part II. 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 bom 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 h'mited 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 bo accounted for. We should boar in mind that these colours do not appear in the male at buih, 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 strongly- marked 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 occui-ring almost exclusively, as may be collected from the previous details, in those groups and sub- groups of mammals, which present other and strongly-marked secondary sexual character's ; these being likewise due to sexual selection. Quadrupeds manifestly take notice of colour. Sir S. Baker repeatedly obseiwed that the African elephant and rhinoceros attacked white or grey horses with special fury. I have else- where shewn ** that half-wild horses apparently prefer to pair with those of the same colour, and that herds of faUow-deer 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 suflScient to rouse him.”“ In an earlier chapter we have seen that the mental powers of the higher tinimals do not differ in kind, though greatly iii 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 “ ‘ The Variation of Animals and ‘ Essays and Observations by Plants under Domestication,’ 1868, J. Hunter,’ edited by Owen, 186T. voL ii. pp. 102, 103. vol. i. p. 191. Mammals — Ornaments. 541 Chap. XVIII. 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 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 deeply-furrowed and gaudily-coloured 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 thfl.n the face ; but this is not more strange than that the tails of many birds should be especially decorated. 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 tavoui- 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 emas- culated 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 long-continued preference of the indi- viduals 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 attractions. ^ Sir S Baker, ‘ The Nile Tributaries of Abyssinia,’ 1867. 542 The Descent of Man. Paet II. Equal transmission of ornamental characters to both sexes. — 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 pro- tection ; 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 musk-rat,®° 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 instence of concealment through colour; yet this principle partly fails in a closely-allied 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 snow-clad 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 injm'ious; 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 appa- rently is the direct result of the conditions to which they have long been exposed. 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 rein- deer. The roe, for instance, has a red summer and a greyish- white winter coat; and the latter may perhaps serve as a protection to the animal whilst wandering through the leafless thickets, sprinkled with snow and hoar-frost. If the above- named animals were gradually to extend their range into regions perpetually covered with snow, their pale winter-coats would probably be rendered through natural selection, whiter and whiter, until they became as white as snow. Mr. Keeks has given me a cmious instance of an animal profit- ing by being peculiarly coloured. He raised from fifty to sixty white and brown jnebald rabbits in a large walled orchard; and he had at the same time some similarly colom-ed cats in his Fiber zibctMcus, Audubou and Glirium ordine,’ 1778, p. 7. Wliat Bachman, ‘ The Quadrupeds of N. I have called the roe is the Caprcolas America,’ 1846, p. 109. sibin'cits subecaiuiattis of Pallas. “ ‘ Novtt’ species Quadrupedum e Chap. X71IL Mammals — Spots and Stripes. 543 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 parti-coloured brethren. The result was iiat, within eighteen months, every one of these parti- coloured 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 dui’ing the dusk it would not easily be recognised and might be attacked by a beast of prey. Hence it is, as Mr. Belt beheves,®’ 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 con- spicuous 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 derlyanus than in the female ; — ^when we see a similar difference between the sexes of the curiously-ornamented 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 acquii-ed by the males and their coloui-s 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 {Strepsiuros 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 purplish-red, 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, narrowly-edged with black, covers the face ‘ The Naturalist in Nicaragua,’ p. 249. 544 The Descent of Man. J’aut II vip to the eyes (fig. 71); there are tlirec white stri^xis on tlie forehead, and the ears are marked with white. Tlie fa-wms of this species are of a uniform pale yellowish-brown. In Damalu alhifrons the colouring of the head dilfers from that in the last species in a single white stripe replacing the three stripes, and rig. 70. Tragelaphus scriptus, male (from the Knowsloy Menagerie'). in the ears being almost wholly white.'** After having studied to the best of my ability the sexual differences of animals Ixj- longing to all classes, I cannot avoid the conclusion that the curiously-arranged colours of many antelopes, though common to both sexes, are the result of sexual selection primarily applied to the male. ” See the fine plates in A. Smith’s ‘ Gleanings from the Mcn.ngcrie w ‘ Zoology of S. Africa,’ and Dr. Gr.ay’s Knowsley.’ Chap. XVIII. Mammals — Spots and Stripes. 545 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^® 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 shght evidence that his beauty may be due to sexual Fig. Yi. Datnalis pygarga, male (from the Knowslcy Menagerie). 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 on the open plains of South Africa. Burchell'''’ in de- scribing a herd says, “ their sleek ribs glistened in the sun, and „ bnghtness and regularity of their striped coats presented a picture of extraordinary beauty, in which probably they are IrZ ‘ h « ‘Travels in South Africa,’ 1824, P- 5- vol. ii. p. 31.5. 546 The Descent of Man. Part II, " not sTirpassed by any other quadruped.” But as throughout the whole group of the Equidse the sexes are identical in colour, we have here no evidence of sexual selection. Nevertheless ho who attributes the white and dark vertical stripes on the flanks of vai-ious antelopes to this process, will probably extend the same view to the Eoyal 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 coloiiring 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 (^Oervus 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 hog-deer {Hyelaphus porcinus) the spots are extremely con- spicuous during the summer when the coat is reddish-brown, but quite disappear during the winter when the coat is brown.^’ 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 in- formed 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. Ikom 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 hving members of the deer family are the descendants of some ancient Dr. Gray, ‘ Gleanings from the deer of Ceylon, says it is more Menagerie of Knowsley,’ p. 64. brightly spotted with white than Mr. Blyth, in speaking (‘ Land and the common hog-deer, at the se.ison Water,’ 1869, p. 42) of the hog- when it renews its horns. Chap. XVlIl. Mammals — Spots and Stripes. 547 species -whicli, like the axis deer, was spotted at all ages and seasons. A still naore ancient progenitor probably somewhat resembled the Eyomoschus aquaticus — for this animal is spotted, and the hornless males have large exserted canine teeth, of which some few true deer stiU retain rudiments. Hyomoschus, also, offers one of those interesting cases of a form Unking to- gether two groups, for it is intermediate in certain osteological characters between the pachyderms and ruminants, which were formerly thought to be quite distinct.'*^ 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 hon 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 tapus, Eritz 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 reddish-brown, 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 dun-coloiued 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."*® Hence the dis- appearance of the spots and stripes in our adult existing deer, “ Falconer and Cautley, ‘Proc. « ‘ The Variation of Animals and Geolof:. Soc.’ 1843; and Falconer’s Plants under Domestication,’ 1868, ‘Pal. Memoirs,’ vol. i. p. 196. vol. i. p. 61-64. 2 N 2 The Descent of Man. 1’abt II, 548 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 «.• TT j r nibicundus. This and the following figures (from Prof;G^ai) S™^ development of the hair on the head. the cross shoulder-stripe, whilst those which inhabit Africa are conspicuously striped, with the partial exception of A. W which has only the cross shoulder-stripe generally so^ faint bars on the legs ; and this species inhabits the almost inter- mediate region of Upper Egypt and Abyssinia.'' ■*'* ‘ Proc. Zool. Soc.’ 1862, p. 164. See, also, Dr. Hartmann. ‘Ann. d. I.andw.’ Bd. xliii. s. 222. Chap. XVJII. Bemity of the Quaarnimana. 549 Quadrumana. — 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 aa’e 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 7G) Kg. 73. Head of Semnopithecus comatus Fig. 1i. Head of Cebus capucinus. Fig. 75. ITcadof Atclesmar-inatus. Fig. 76. Head ot Cebus vellerosus. .‘•erve 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; 550 The Descent of Man. Fart II. and it is inconceivable that they can be of use in any ordinary way to these animals. If so, they have ijrobably been gained through sexual selection, though transmitted equa;lly, or almost equally to both sexes. With many of the Quadrumana, we have addi- tional 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 females. 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 bluish-white colom-. The face of Macacus lasiotus is diidy flesh-coloured, with a defined red spot on each cheek. The appearance of Oercocebus ivthiops is grotesque, with its black face, white whiskers and collar, chesnut 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,^® being often pure white, sometimes bright yellow, or reddish. The whole face of the South American Bracliyurus calvus is of a “glowing scarlet hue;” but this colour does not appear until the animal is nearly mature.'® The naked skin of the face differs wonderfully in colour in the various species. It is often brown or flesh- colour, 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 strongly-coloured faces, the colours are dull or absent during early youth. This likewise holds good with the mandrill and Ehesus, 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. I observed this fact in the ‘ Hist. Nat. des Maminifbrcs.’ tom. Zoological Gardens; and many cases i. 1824. may be seen in the coloured plates in Bates, ‘ The Naturalist on the Geofiroy St.-Hilaire and F. Cuvier, Amazons,’ 1863, vol. ii. p. 310. Chap. XVIII. Beauty of the Quadrumana. 551 Although many kinds of monkeys are far from beautiful accord- ing to oim taste, other species are universally admired for their elegant appearance and bright colours. The Semnopithecus nemmis, though j)eculiarly coloured, is described as exti’emely 552 The Descent of Man. Paht IL. pretty ; the orange-tinted face is suiTounded by long •whiBkors of glossy whiteness, with a line of chesnut-red over the eye- brows ; the fur on the back is of a delicate grey, with a square patch on the loins, the tail and the fore-arms being of a pure white ; a gorget of chesnut surmounts the chest ; the thighs are black, with the legs chesnut-red. I will mention only two other monkeys for their beauty; and I have selected these as pre- senting slight sexual differences in colour, which renders it in some degi-ee probable that both sexes owe their elegant appearance to sexual selection. In the moustache-monkey (^Cercopithecus cephus) the general colour of the fur is mottled- greenish with the throat white ; in the male the end of the tail is chesnut, but the face is the most ornamented part, the skin being chiefly bluish-grey, 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 orange-coloured, 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 admhing the lieauty 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 chesnut ; in the male the inner sides of the thighs and the abdomen are delicate fawn-coloured, and the top of the head is black ; the face and eai’s are intensely black, contrasting finely with a white transverse crest over the eye-brows and a long white peaked bear'd, of which the basal portion is black.^'^ 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 acquhed through sexual selection exclusively as ornaments. Summary.— 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 I have seen most of the above Mr. W. C. Martin’s ‘Hat. o( monkeys in the Zoological Society’s Mammalia,’ 1841, p. 460 5 see also Gardens. The description of the pp. 475 523. Semnojnthecm nermvus is taken from Chap. XVIU. Mammals — Siimmaiy. 553 acquia-ed or modified tiu'ougli 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 males. Corcoplthpcus diana (from Brchm). Tliere 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 ijower- ful odours emitted by the males during the breeding-season ; the odoriferous glands having been acquired through sexual selection. Wliethcr the samo view can be extended to tlie A'oico 554 The Desce^it of Man. Part IT. is doubtful, for tbe vocal orgaus of the males must have been strengthened by use during maturity, under the powerful excite- ments of love, jealousy or rage, and will consequently have been tmusmitted 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 bo 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 ante- lopes, though properly serving as weapons of offence or defence, have been partly modified for ornament. ■^VTien the male differs in colour from the female, he generally exhibits darker and more strongly-contrasted tints. We do not in this class meet with the splendid red, blue, yeUow, 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 orna- mental 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 sub-groups with other secondary sexual characters serving for war or for ornament, will be found to hold good, if wo look back to the various cases given in this and the last chapter. 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 sec, their ab.sence in tliis sex can be accounted, for only by the Chap. XVIII. Mammals — Summary. 555 form of inheritance which has prevailed. Finally, with quad- rupeds 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. ( 556 ) Part III. SEXUAL SELECTION IN EELATION TO MAN, AND CONCLUSION. CHAPTER XIX. Secondary Sexual Characters of Man. Differences between man and woman — Causes of such differences and of certain characters common to both sexes — Law of battle — Differences in mental powers, and voice — On the influence of beauty in determining the marriages of mankind — Attention paid by savages to ornaments — Their ideas of beauty in woman — The tendency to exaggerate each natural peculiarity. With mankind tlio differences between tbe sexes are greater than in most of the Quadrnmana, 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 plainly-pronounced muscles. Owing to the relation which exists between muscular development and the projection of the brows,^ the superciliary ridge is generally more marked in man than in woman. His body, and especially his face, is more hairy, and Ms voice has a different and more powerful tone. In certain races the women are said to differ shghtly 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 some- “ thing of the colour of half-roasted coffee.” ^ 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 sexes, as may be seen when both have been equally exposed. * Schaaffhausen, translation in ^ ‘The Heart of Africa,’ English ‘Anthropological Review,’ Oct. 1868, Transl. 1873, vol. i. p. 544. pp. 419, 420, 427. Chap. XIX. Man — Sexual Differences. 557 Man is more courageous, pugnacious and energetic than woman, and has a more inventive genius. His brain is abso- lutely 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;® 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 man. 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 abun- dant 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 cha- racters, and in the formation of her skull, is said to be inter- mediate between the child and the man. * Again, as the young of closely allied though distinct species do not differ nearjy 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 race- differences cannot be detected in the infantile skull.® In regard to colour, the new-born negro child is reddish nut-brown, which soon becomes slaty-grey ; the black colour being fully developed within a year in the Soudan, but not until three years in Egypt. The eyes of the negi'o are at first blue, and the hair chesnut- brown rather than black, being curled only at the ends. The children of the Australians immediately after bii’th are yellowish- brown, and become dark at a later age. Those of the Guaranys of Paraguay are whitish-yellow, but they acquire in the course of a few weeks the yellowish-brown tint of their parents. Similar observations have been made in other parts of America.® ® Ecker, translation in ‘Antliro- 355; Vogt, ‘ Lectures on Man,’ Eng. pological Review,’ Oct. 1868, pp. 351- translat. p. 81. 356. The comparison of the form ® Schaaffhausen, ‘ Anthropolog. of the skull in men and women has Review,’ ibid. p. 429. been followed out with much care ® Pruner-Bey, on negro infants by Welcker. as quoted by Vogt, ‘Lectures on ‘ Ecker and Welcker, ibid. p. 352, Man,’ Eng. translat. 1864, p. 189 : 558 The Descent of Man. Paet 111. 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 the Ce&Ms azaroeJ 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,® and agree in this respect with mankind. In the gorilla and certain other monkeys, the cranium of the adult male presents a strongly-marked sagittal crest, which is absent in the female ; and Bcker found a trace of a sunilar difference between the two sexes in the Australians.® 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 weU-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 coloui’ 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 riile. 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 Eussia, 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 in Sikhim, the Bhoteas, Hindoos, Burmese, and for further facts on negro infants, as quoted from Winterbottom and Camper, see Lawrence, ‘ Lectures on Physiology,’ &c. 1822, p. 451. For the infants of the Guaranys, see Rengger, ‘ Sttugethiere,’ &c. s. 3. See also Qodron, ‘ De I’Espfece,’ tom. ii. 1859, p. 253. For the Austra- lians, Waitz, ‘ Introduct. to Anthro- pology,’ Eng. translat. 1863, p. 99. 7 Rengger, ‘ Siiugethiere,’ &c. 1830, s. 49. * As in Macacus cynoinolgus (Dcs- marest, ‘ Mammalogie,’ p. 65), and in Hyldbates agilis (Geoffroy St.- Hilaire and F. Cuvier, ‘ Hist. Nat. des Mamm.’ 1824, tom. i. p. 2). ® ‘ Anthropological Review,’ Oct. 1868, p. 353. 559 Chap, XIX. Man — Sextial Differences. 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 hn.ir of the head, and in such cases it is always of a lighter hue, being often pui-e white, sometimes yellow or reddish.^®- In regai-d 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.” 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 con- siderably greater difference between the sexes, as in the size of the canine teeth, in the development and colour of the hair, and especially in the colour of the naked parts of the skin, than in mankind. 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 through- out the animal kingdom. In the excellent obseiwations made on board the Novara, 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 back-bone and of the arms, in various % Urns Mr. D. Forbes has never, as he informs me, seen an instance with the Aymaras and Quichuas of S. America. '* This is the case with the fe- males of several species of Hylobates, see Geoffroy St.-Hiliare and F. Cu- vier, ‘ Hist. Nat. des Mamm.’ tom. i. See, also, on H. lar, ‘ Penny Cy- clopedia,’ vol. ii. pp. 149, 150. The results were deduced by Dr. Weisbach from the measure- ments made by Drs. K. Scherzor and Schwarz, see ‘ Rcise der Novara : Anthropolog. Theil,’ 1867, ss. 216 231, 234, 236, 239, 269. Mr. Blyth informs me that he has only seen one instance of the beard, whiskers, &c., in a monkey becoming white with old age, as is so commonly the case with us. This, however, occurred in an .aged Macacua cynomolgus, kept in confinement, whose moustaches were “ remarkably long and hu- “ man-like.” Altogether this old monkey presented a ludicrous re- semblance to one of the reigning monarchs of Europe, after whom he was universally nick-named. In certain races of man the hair on the head hardly ever becomes grey ; The Descent of Man. Part IIL 560 races ; and nearly all these measui’ements 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. Ealda, according to Martin,^® the men do not acquire beards until the age of thirty or upwards, and even then the beards are very thin. On the Europseo-Asiatic 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.’* East- ward of India beards disappear, as with the Siamese, Malays, Kalmucks, Chinese, and Japanese ; nevertheless the Ainos,’® who inhabit the northernmost islands of the Japan .Ajchipelago, 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.’® On the other hand, the Papuans of the Malay Archipelago, who are nearly as black as negroes, possess well-developed beards.’" In the Pacific Ocean the inhabitants of the Fiji Archipelago have large bushy beards, whilst those of the not distant archi- pelagoes of Tonga and Samoa are beardless; but these men belong to distinct races. In the Ellice group aU 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.” ’® Throughout the great American continent the men may be said to be beardless ; but in almost all the ti-ibes 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 ; 13 ‘Voyage to St. Kilda’ (3rd edit. 1753), p. 37. Sir J. E. Tenaent, ‘ Ceylon,’ vol. ii. 1859, p. 107. Quatrefages, ‘ Revue des Cours Scientifiques,’ Aug. 29, 1868, p. 630 ; Vogt ‘ Lectures on Man,’ Eng. translat. p. 127. On the beards of negroes, Vogt, ‘ Lectures,’ &c. p. 127 ; Waitz, ‘ In- trod uct. to Anthropology,’ Engl, translat. 1863, vol. i. p. 96. It is remarkable that in the United States (‘ Investigations in Military an Anthropological Statistics of Ame rican Soldiers,’ 1869, p. 569) the pure negroes and their crossed oil- spring seem to have bodies almost as hairy as Europeans. ” Wallace, ‘The Malay Arch.’ vol. ii. 1869, p. 178. Dr. J. Barnard Davis On Oce- anic Races, in ‘ Anthropolog. Review, April, 1870, pp. 185, 191. Chap. XIX. Man — -Law of Battle. 561 but occasioually there may bo seen a man, who has ncglectal to pluck out the haii's 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.’® I am informed by Mr. D. Porbes, who particularly attended to this point, that the Aymaras and Quichuas of the Cordillera are remarkably hairless, yet in old age a few stragghng hairs occasionally appear on the chin. The men of these two tribes have very little hair on the various pai-ts 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.®® This fact is analogous with what occui's with some closely allied monkeys; thus the sexes of the chimpanzee are not as different as those of the orang or gorilla.®’ In the irrevious chapters we have seen that with mammals, bh'ds, fishes, insects, &c., many characters, which there is every reason to beheve were primarily gained thi-ough 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 cha- racters peculiar to the male sex together with certain other characters common to both sexes. Law of Battle. —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 con- test is reduced to a system. That excellent observer, Hearne,'-’® Gatlin, ‘North American In- dians,’ 3rd edit. 1842, vol. ii. p. 227. On the Guai'anys, see Azara, ‘ Voy- ages dans I’Amerique Merid.’ toin. ii. 1809, p. 58 ; also Renggor, ‘ Saugethiere von Paraguay,’ s. 3. Prof, and Mrs. Agassiz (‘ Jour- ney in Brazil,’ p. 530) remark that the se.’tes of the American Indians differ less than those of the negroes and of the higher races. See also Kengger, ibid. p. 3, on the Guaranys. Riitimeyer, ‘Die Grenzen der Thierwelt ; eine Betrachtung zu Darwin’s Lehre,’ 1868, s. 54. -- ‘ A Journey from Prince of Wales Fort.’ 8vo. edit. 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 S. America see Azara, ‘Voyages,’ &u. tom. ii. p. 94. 2 0 The Descent of Man. Paut 111. 562 says ; — “ It lias ever been tlie custom among these people for “ the men to wrestle for any woman to whom they are at- “ tached ; and, of coui-se, the strongest party always carries oil “ the prize. A weak man, unless he bo a good hunter, and Avell- “ beloved, is seldom permitted to keep a wife that a stronger “ man thinks worth his notice. Tliis custom prevails through- “ out -all the tribes, and causes a great spirit of emulation among “ their youth, ivho ai’e upon all occasions, from their childhood, “ trying their strength and skill in wresthng.” 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,®^ 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 lirobability a case of reversion to a former state, when the progenitors of man were provided with these weapons, hke 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 lus 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 tvt^o sexes of mankind would ultimately have been oblite- rated. The case is almost parallel with that of many male Euminants, in which the canine teeth hav’e 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 change in his appearance. -3 On the fighting of the male p. 423. On Preshjtis entcUus, see gorillas, see Dr. Savage, in ‘Boston the ‘Indian Field,’ 1859, p. 14tJ Journal of Nat. Hist.’ voL v. 1847, Chap. XIX. Mental powers of Man and Woman 5^3 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 in~ heritauce from his half-human 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 sti-ength will have been kept up. Difference in the Mental Powers of the tiuo Sexes. — With respect to differences of this nature between man and umman, 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 wdld-boar 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 well-known passage in Mmigo 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 ; there- fore it is likely that she would often extend them towards her fellow-creatures. 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 bo 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 5&4 The Descent of Man. Part III. 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 woman — whether 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 (iuclusive both of composition and performance), history, science, and philosophy, with half-a-dozen names under each subject, the two lists would not bear comparison. AVe may also Mer, from the law of the deviation from averages, so weU illustrated by Mr. Galton, in his work on ‘ Hereditary Genius,’ that if men arc capable of a decided pre-eminence over women in many subjects, the average of mental power in man must be above that of woman. Amongst the half-human 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, imless associated with courage, perseverance, and. determined energj". With social animals, the young males have to pass througl?. 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 lands, 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 cliiefly to the male offspring at the corresponding period of manhood. Now, when two men are put into competition, or a man with a woman, both possessed of every mental quality in equal per- fection, save that one has higher energy, perseverance, an-, courage, the latter will generally become more eminent in every pursuit, and will gain the ascendancy.®* He may be said to possess genius — for genius has been declaied by a great J. Stuart Mill remarks (‘The “require most plodding, and long Subjection ofWomen,’ 1869, p. 122), “hammering at single thoughts.” “ The things in which man most What is this but energy and per- “ excels woman are those which severance ? Chap. XIX. Mental powers of Ma7i and Woman. 565 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 imagi- nation 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 re-inforcement of many of our mental faculties by sexual selection, that, firstly, they notoriously undergo a considerable change at puberty,-'^ and, secondly, that eunuchs remain throughout life inferior in tliese 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 the peahen. It must be borne in mind that the tendency in characters acquhed by either sex late in hfe, to be transmitted to the same sex at the same age, and of early acquh’ed 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 hoys 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 traming. 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 genera^ tions 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 udves, 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 “ Maudsley, ‘Mind and Body,’ p. 31. 566 The Desceiit of Man. I'AKT HI. mental powers, and, as a consequence, the present inequality between the sexes.““ Tbice and Musical Powers. — In some species of Quadi'umaua there is a great difference between the adult sexes, in the power of their Yoices and in the develoi>ment of the vocal organs ; and man appears to have inherited this difference from his earlj' progenitors. His vocal cords are about one-third 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 pro- “ minent growth of the thyroid, &c., which accompanies the “ elongation of the cords.”-’ 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 long- continued use of the vocal organs by the male under the ex- citement of love, rage and jealousy. According to Sir Duncan Gibb,“® the voice and the form of the larynx differ in the difterent races of mankind ; but with the Tartars, Chinese, &c., the voice of the male is said not to differ so much from that of the female, as in most other races. 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 pro- duced consist, I believe in all cases, of the same note, repeated rhythmically ; ^ and this is sometimes pleasing even to the eai's of man. The chief and, in some cases, exclusive juirposo appears to be either to call or charm the opposite sex. Tbe sounds imoduccd by fishes are said in some cases to bo made only by the males during the breeding-season. All the An observ.ition by Vogt bears on this subject : he says, “ It is .a “ remarkable circumstance, that the “ difTerence between the sexes, ns “ regards the cranial cavity, in- “ creases with the development of *• the race, so that the male Euro- “ pean excels much more the female, “ than the negro the negress. “ Welcker confirms this statement ‘■of Huschke from liis moasurc- “ ments of negro and German “ skulls.” But Vogt admits (‘ Lec- tures on Man,’ Eng. translat. 18G4. p. 81) that more observations are requisite on this point. Owen, ‘Anatomy of Verte- brates,’ vol. iii. p. 603. "* ‘ Journal of the Antbropolog. Soc.’ April, 1869, p. Ivii. and Ixvi. Dr. Scudder, ‘Notes on Stri- ; 568 The Descent of Man. Pai’.t 111. 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 powers more esjiecially during the season of courtship. This gibbon is not the only species in the genus which sings, for my son, Francis Darwin, attentively listened in the Zoo- logical Gardens to 11. leticiscus 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. AVe have, how- ever, at last a clear account by a well-known observer, the Eev. S. Lockwood,"^ of the musical powers of an American species, the Eesperomys cognatus, belonging to a genus distinct from that of the English mouse. This little animal w'as kept in confine- ment, 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 shai"p “ and D, to 0 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 jnouse “ had no ear for time, yet she would keep to the key of B “ (two fiats) 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 co-existence 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 con- tinuity of such vibrations, and in their want of harmony wter se, that a noise differs from a musical note. Thus an ear to bo capable of discriminating noises — and the high importance ot this power to all animals is admitted by every one — must be sen- sitive 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 arc struck.®^ As stated The ‘American Naturalist,’ Helmholtz, ‘Thwric Phys. de 1871, p. 761. la Musique,’ 1868, ji. 187. Chap. XIX. Man — -Musical Powers. 569 in a previous chapter, similiar observations have been made on the haii-s of the antennse 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 par- ticular tones.^'* 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.” 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. Hehnholtz has explained on physio- logical principles why concords are agreeable, and discords dis- agreeable to the human ear ; but we are little concerned with these, as music in harmony is a late invention. We are more con- cerned with melody, and here again, according to Hehnholtz, 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 mai-ked are the octave, the twelfth, the second octave, &c., all harmonies of the fundamental pre- dominant note ; any two notes of our scale have many of these harmonic over-tones 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 common — that 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, Avould be useless ; and this it is impossible to believe. Human song is generally admitted to bo the basis or origin of instrumental music. As neither the enjoyment nor the capacity of producing musical notes are faculties of the least Several accounts have been another instance of a dog always j iiblished to this effect. Mr. Peach whining, when one note on a con- writes to me that he has repeatedly certina, wliich w.as out of tunc, was found that an old dog of his howls played. when B flat is sounded on the flute, Mr. K. Brown, in ‘ Proc. Zool. and to no ether note. I may add Soc.’ ISdS, ji. 410. 570 The Descent of Man. r.MiT II 1. use to man in reference to his daily habits of life, they must be ranked amongst the most mysterious with which ho is endowed. They are present, though in a very rude condition, in men of all races, even the most savage ; hut 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,®® “ doubts “ whether even amongst the nations of Western Europe, in- “ timately connected as they are by close and frequent intcr- “ course, the music of the one is interpreted in the same sense by “ the others. By travelling eastwards we find that there is cer- “ tainly a different language of music. Songs of joy and dancc- “ accompaniments are no longer, as with us, in the major keys, “ but always in the minor.” Whether or not the half-human 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, Ibund 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 Uke- wise so ancient, that many persons have felt astom'shed that it should have arisen during the earhest 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 Hot- tentots and Negi’oes 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 bh-ds which never naturally sing, can without much difficulty be taught to do so; thus a house-sparrow has learnt the song of a mmet. As these two species are closely allied, and belong to the order of Insessorcs, which includes nearly all the singing-birds in the world, it is possible that a progenitor of the sparrow may liave been a songster. It is more remarkable that parrots, belonging to a group distinct from the Insessores, and having difi’crcntly ‘.Journal of Anthropolog. Soc.’ com! edition, J8C9, which cont.nin Oct. 1870, ]). civ. See also the an admirable account of the habitf several later chapters in Sir .Tolm of .savages. Lubbock’s ‘ Prehistoric Times,’ .se- Chap. XTX. Man — Musical Poivers. 571 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 bo 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 pui-pose, having been utilised for some distinct purpose.^® Hence the capacity for high musical development, which the savage races of man possess, may be due either to the practice by our semi-human progenitors of some rude form of music, or simply to their- having acquired the proper vocal organs for a. different purpose. J3ut in this latter case we must assume, as in the above instance of parrots, and as seems to occur with many animals, that they already possessed some sense of melody. Music arouses in us various emotions, but not the more terrible ones of horror, fear, rage, &c. It awakens the gentler feehngs 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 ardoiu’ for war. These powerful and mingled feelings may well give rise to the sense of subhmity. 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 com- monest 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 Eichter says, tells us of things we have not seen and shall “ not see.” Conversely, when vivid emotions are felt and ex- pressed 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, “ while the company, as if touched by a musical wave, murmur Since this chapter was printed, I have seen a valuable article by Mr. Chauncey Wright (‘ North Ainer. Keview,’ 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 use- “ ful power will bring with it many “ resulting advantages as well as “ limiting disadvantages, actual or “ possible, which the principle of “ utility m.ay not h.ave comprehended “ in its action.” As I have attempted to shew in an early chapter of this work, this princiide has an impor- tant bearing on the acquisition by man of some of his mental charac- teristics. 572 The Descent of Man. Pakt hi. “ a chorus in perfect unison.” Even monkeys express strong feelings in different tones— anger and impatience by low, — fear and pain by high notes.®® The sensatio»s 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 thoughts of a long-past age. 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 half-human an- cestors, 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 long- joast 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 deve- loped from the tones used in impassioned speech. We must suppose that the rhythms and cadences of oratory are derived from previously developed musical powers.” 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."*® Win-.vood Keade, ‘The Martyr- dom of Man,’ 1872, p. 441, and ' African Sketch Book,’ 1873, vol. ii. p. 313. Eenggei', ‘ Saugethiere von Paraguay ,’ s. 49. See the very interesting dis- cussion on the ‘ Origin and Function of Music,’ by Mr. Herbert Spencer, in his collected ‘ Essays,’ 1858, p. 359. Mr. Spencer comes to an ex- actly opposite conclusion to that at which 1 have arrived. He con- cludes, as did Diderot formerly, that the cadences used in emotional speech afi’ord 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 arc 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 in- teresting discussion on the relations between poetry, recitative, and song. I find in Lord Monboddo’s ‘Origin of L.anguage,’ vol.i. (1774), p. 409, that Dr. Blacklock Ivkewise thought “ that the first language “among men was music, and that “ before our ideas were expressed by Chap. XIX. Man — Love of Ornament. 573 As the males of several quaclrumauous animals have their vocal organs much more developed than in the females, and as a gibbon, one of the anthropomorphous apes, pours forth a wholo octave of musical notes and may be said to sing, it appears pro- bable 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.'^ Eut if so, this must have occurred long ago, before our ancestors had become suflaciently 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 half-human ancestors long ago aroused each other’s ardent passions, during their courtship aud rivalry. Tilt Influence of Beauty in determining the Marriages of Man- kind.— In civilised life man is largely, but by no means exclu- sively, 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 tliis subject is to study the habits of existing semi-civilised 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 ginatest attention to their personal appearance.''^ That they have “ iu'ticuliite sounds, they were com- “ municated by tones, varied accord- “ ing to difl'erent. degrees of gravity “ .and acuteness.” ■*' See an interesting discussion on this subject by Hiickel, ‘ Gene- rclle Morph,’ B. ii. 1866, s. 24G. A full and excellent account of the manner in which sav.ages in all parts of the world ornament them- selves, is given by the Italian tra- a'eller. Prof. Mantegazza, ‘ Rio de la Plata, Viaggi e Studi,’ 1867, ]>p. 525-545 ; all the following state- ments, when other references are not given, are t.aken from this work. See, also, Waitz, ‘ Introduct. to Anthropolog.’ Eng. transl. vol. i. 1863, p. 275, et passim. Lawrence also gives very full details in his 574 The Descent of Man. Paet III. 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 cliica necessary to paint “ liimself red.” The ancient barbarians of Europe during the Eeindeer 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, necklace.s, armlets, ear-rings, &c. 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 gaiments.” In one part of Africa the eyelids are coloured black ; in another the nails are colomed yellow or purple. In many places the hair is dyed of various tints. In different countries the teeth are stained black, red, blue, &c., 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 Avas followed by the Jews of old, and by the ancient Britons. In AMca 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 imtil the cheeks “or temples have been gashed.” In South America, as Humboldt remarks, “ a mother would be accused of “ culpable indifference towards her childi’en, 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 ‘ 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 Hud hair, and piercing their teeth. Humboldt, ‘ Personal Narr.ative,’ 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 Nile Tributaries,’ 1867; ‘ The Albert N’yanza,’ 1866, vol. i, p. 218. Chap. XIX. Man — Love of Ornament. 575 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^® deem a much flattened head “an “ essential point of beauty.” The hah- is ti-eated with especial care in various countries ; it is allowed to grow to full length, so as to reach to the ground, oi- ls combed into “ a compact frizzled mop, which is the Papuan’s “pride and glory.”-"* In Northern Africa “a man requires a “ period of from eight to ten years to perfect liis 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*^ 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 Eurojpeans, 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 those of a saw, or pierce them with holes, into which they insert studs. 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 in- serted 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 Avood, 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 colom-ed piece of wood which is passed through the hole. In Central Africa the women perforate the lower lip and Avear a crystal, Avhich, from the movement of the tongue, has “ a “ Avrigghng motion, indescribably ludicrous during conversation.” '** Quoted by Prichard, ‘Phys. 445. Ou the coiffure of the Afri- Hist. of Maukiud,’ 4th edit. vol. i. caus. Sir S. Baker, ‘The Albert 1851, p. 321. N’yauza,’ vol. i. p. 210. ■*“ On the Papuans, Wallace, ‘ Travels,’ p. 533. The JIalay Archipelago,’ vol. ii. ]>. 576 The Descent of Man. Paut nr. The -wife of the chief of Latoolca told Sir S. Baker” 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 v ould she “ ‘ be without the pelele ? She would not be a woman at all “ ' with a mouth like a man, but no beard.’ ”” 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 apjDear 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,^ and thus mutilations, from whatever cause first made, soon come to be valued as distinctive marks. But self-adornment, vanity, and the admiration of others, seem to be the emnmonest motives. In regard to tattoo- ing, I was told hy 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®' 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.®- ‘ The Albert K’y.inza,’ I860, vol. i. p. 217. Livingstone, ‘ British Associa- tion,’ 1860 ; report given in the ‘ AthenKiim,’ July 7, 1860, p. 29. Sir S. Baker (ibid. vol. i. p. 210) speaking of 1 he natives of Central Africa says, “every tribe “has a distinct .and unchanging “ fashion for dressing the hair.” See Agassiz (‘Journey in Br.azil.’ 1868, p. 318) on the invariability of the tattooing of the Amazonian Indians. Rev. R. Taylor, ‘ New Zealand and its Inhabitants,’ 1855, p. 152. Mantegazza, ‘ Viaggi o StuJi, p. 542. CnAP. XIX. Man — Beauty. 577 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 orna- mented. As the women are made by savages to perform the gi-eatest 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, &c., 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 rude pictures. 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“ gives an amusing account of a Bush-woman 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 Eeade 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.®^ In several regions the women wear charms and use love-philters to gain the affections of the men; and Mr. Brown enumerates four plants used for this purpose by the women of North-Western America.^® ” ‘Travels in S. Africa,’ 1824, vol. i. p. 414. *'• See, for references, Gerland ‘ Ueber das Aussterben der Natnrvol- ker,’ 1868, s. 51, 53, 55 ; also Azara, • Voyages,’ &c. tom. ii. p. 116. On the vegetable productions used by the North-Western Ameri- can Indians, ‘ Pharmaceutical Jour- nal,’ vol. X. 2 P 578 The Descent of Man. Part III. Hearne,®* 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 cheek-bones, three or four broad “ black lines across each cheek, a low forehead, a large broad “ cliin, 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 cheek- “ bones, very broad noses, and enormous ears ; ” 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 red-haired barbarians.” It is well known, as Hue 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.’” Einlayson, 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 cheek-bones. It is, therefore, not wonderful that “ beauty, “ according to our notion is a stranger to them. Yet they con- “ sider their own females to be much more beautiful than those “ of Europe.”®® 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.®* He once saw a ‘ A Journey from Prince of W.iles Fort,’ 8vo. edit. 1796, p. 89. Quoted 'by Prichard, ‘ Php. Hist, of Mankind,’ 3rd edit. 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. *“ Prichard, as taken from Craw- ford and Finlayson, ‘ Phys. Hist, of Mankind,’ vol. iv. pp. 534, 535. ““ Idem illustrissimus viator dixit mihi prsecinctorium vel tabulam foemin.T:, quod nobis teterrimum est, quondam pcrm.agno o:stimari ab hominibus in hSc gente. Nunc res mutata est, et consent talem con- formationcm miuime optandam esse. Chap. XIX. Man — Beauty. 579 ■^oman 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 pecu- liarity ; 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 Ur go. Nothing can be more “ hateful to a negro than the opposite form.” 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 conforma- “ tions.” He in return praised the glossy jet of their skins and the lovely depression of their noses ; this they said was, “ honey- “ mouth,” nevertheless they gave him food. The African Moors, also, “ knitted their brows and seemed to shudder ” at the white- ness 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 " hke a white ape ? ” On the western coast, as Mr. Winwood Eeade 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 are white, and partly to their thinking it a sign of ill-health. The Banyai of the more southern part of the continent are negroes, but “ a great many of them are of a light cofifee-and-milk “ colour, and, indeed, this colour is considered handsome “ throughout the whole country ; ” so that here we have a different standard of taste. With the Kafirs, 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 comphment by “ a Kafir. 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.” Mr. Galton, in speaking to me about the natives of S. Africa, remarked that their ideas of ‘The Anthropological Review,’ November, 1864, p. 237. For ad- ditional references, see Waitz, ‘ In- troduce to Anthropology,’ Eng. translat. 1863, vol. i. p. 105. Mungo Park’s ‘ Travels in Africa,’ 4to. 1816, pp. 53, 131. Burton’s statement is quoted by Schaaff hausen, ‘ Archiv fiir Anthro- polog.’ 1866, s. 163. On the Banyai, Livingstone, ‘Travels,’ p. 64. On the Kafirs, the Rev. J. Shooter ‘The Kafirs of Natal and the Zulu Country,’ 1857, p. 1. 2 P 2 580 The Descent of Man. Part III. iKiauty seem very different from ours ; for in one tribe two slim, slight, and pretty girls were not admired by the natives. 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 liad 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 Yura- caras, who inhabit the wooded, damp slopes of the eastern Cordillera, are remarkably pale-coloured, as their name in their own language expresses ; nevertheless they consider European women as very inferior to their own.®^ 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 oflice 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 con- sidered 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 he 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 hairs 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.®® •* For the Javans and Cochin- Chinese, see Waitz, ‘Intrcduct. to Anthropology,’ Eng. translat. vol. i. p. 305. On the Ynra-caras, A. •J’Orligny, as quoted in Prichard, ‘ Phys. Hist, of Mankind,’ vol. v. 3rd edit. p. 476. ‘ North American Indians,’ by G. Gatlin, 3rd edit. 1842, vol. i. p. 49 ; vol. ii. p. 227. On the natives of Vancouver’s Island, see Sproat, ‘ Scenes and Studies of Savage Life,’ 1868, p. 25. On the Indians of Paraguay, Azara, ‘ Voyages,’ tom. iL p. 105. Chap. XIX. Man — Beauty. 581 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.®^ On the other hand, bearded races admire and greatly value their beards ; among the Anglo-Saxons 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.”®® 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 archi- pelagoes 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.” ®® We thus see how widely the different races of man differ in their taste for the beautiful. In every nation sufficiently ad- vanced 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.®’ Under this point of view it is weU to compare in our mind the Jupiter or Apollo of the Greeks with the Egyptian or Assyrian statues ; and these with the hideous bas-rehefs on the ruined buil^ngs of Central America. I have met with very few statements opposed to this conclusion. On the Siamese, Prichard, ibid. Tol. iv. p. 533. On the Japanese, Veitch in ‘Gardeners’ Chronicle,’ 1860, p. 1104. On the New Zea- landers. Mantegazza, ‘ Viaggi e Studi,’ 1867, p. 526. For the other nations mentioned, see references in Lawrence, ‘ Lectures on Physiology,’ &c. 1822, p. 272. Lubbock, ‘ Origin of Civilisa- tion,’ 1870, p. 321. Dr. Barnard Davis quotes Mr. Prichard and others for these facts in regard to the Polynesians, iu ‘ Anthropological Review,’ April, 1870, p. 185, 191. Ch. Comte has remarks to this effect in his ‘ Traits de Legislation,’ 3rd edit. 1837, p. 136. 582 The Descent of Man. Part III. Mr. Winwood Eeade, however, who has had ample oppor- tunities for observation, not only with the negroes of the West Coast of Africa, hut 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. Kohlfs writes to me to the same effect with respect to Bornu and the countries inhabited by the Pullo tribes. Mr. Eeade 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. Eeade 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 aro exceptional types with the inhabitants of Africa. Notwithstand- ing the foregoing statements, Mr. Eeade 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 hps 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 good-looking negress.®* The general truth of the principle, long ago insisted on by Humboldt,®® that man admires and often tries to exaggerate whatever chai-acters 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 The ‘African Sketch Book,’ vol. ii. 1873, pp. 253, 394, 521. The Fnegians, as I have been in- formed by a missionary who long resided with them, consider Euro- pean 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 in- deed 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, ‘ Anthropological Review,’ March, 1864, p. 245. ‘ Personal Karrative,’ Eng. tr.anslat. vol. iv. p. 518, and else- where. M.antegazza, in his ‘ Viaggi e Studi,’ 1867, strongly insists on this same principle. Chap. XTX. Man — Beatity. 583 peculiarity. Many American Indians are known to admire a head so extremely flattened as to appear to us idiotic. The natives on the north-western 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 “ ii^creasing 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 new-born children.” On the other hand, “ a broad, “ well-rounded occiput is considered a great beauty ” by the natives of the Fiji islands.™ 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 long-nose is considered as an insult, and they compress the noses and fore • heads 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.’'^ The Chinese have by nature un- usually small feet ; ™ 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 had any such intention in painting themselves. 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 di'63sing their hair ; they never imitate other tribes, " but simply On the skulls of the American tribes, see Nott and Gliddon, ‘Types of Mankind,’ 1854, p. 440 ; Prichard, ‘ Phys. Hist, of Mankind,’ vol. i. 3rd edit. p. 321 ; on the natives of Arakhan, ."bid. vol. iv. p. 537. Wilson, ‘ Physical Ethnology,’ Smithsonif.n Institution, 1863, p. 288 ; on the Kijians, p. 290. Sir .1. Lubbock (‘ Prehistoric Times,’ 2nd edit. 1869, p. 506) gives an excellent rdsum^ on this subject. ” On the Huns, Godron, ‘ De I’Espfece,’ tom. ii. 1859, p. 300. On the Tahitians, Waitz, ‘Anthro- polog.’ 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. This fact was ascertained in the ‘Reise der Novara : Anthropolog. ’riiiel,’ Dr. Weisbach, 1867, s. 265, 584 The Descent of Man. Part III. “ vie with each other in the superlativoness of their own style.” Dr. Wilson, in speaking of the compressed skulls of various American races, adds, “ such usages are among the least eradi- “ cable, and long survive the shock of revolutions that change “ dynasties and efface more important national peculiarities.”'* The same principle comes into play in the art of breedmg; and we can thus understand, as I have elsewhere explained,''^ 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 more developed. The senses of man and of the lower animals seem to be so constituted that brilliant colours and certain forms, as weU 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’® 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 endmu any great change ; but they like variety, and admii'e each cha- racteristic carried to a moderate extreme.’® 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 cheek-bones, a depressed nose, and a black skin, admire these peculiarities when strongly marked. ‘ Smithsonian Institution,’ 1863, p. 289. On the fashions of Arab women, Sir S. Baker, ‘The Nile Tributaries,’ 1867, p. 121. ‘The Variation of Animals and Plants under Domestication,’ vol. i. p. 214 ; vol. ii. p. 240. Schaaffbausen, ‘Archly fUr Anthropologie,’ 1866, s. 164. Mr. Bain hiis collected (‘ Men- tal and Moral Science,’ 1868, pp. 304-314) about a dozen more or loss different theories of the idea of beauty ; but none are quite the same us that here given. Chap. XX. Mu71 — Sexual Selection. 585 No doubt characters of all kinds may be too much developed for beauty. Hence a perfect beauty, which impli^ 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 samo 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 cha- racters a little exaggerated beyond the then existing common standard. CHAPTHK XX. Seoondaet Sexual Chabactees op Man — continued. Ou the effects of the continued selection of women .nccording to a different standard of beauty in each race — On the causes which interfere with sexual selection in civilised and savage nations — Conditions favourable to sexual selection during primeval times — On the manner of action of sexual selection with mankind — On the women in savage tribes having some power to choose their husbands — Absence of hair on the body, and development of the beard — Colour of the skin — Summary. 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 pre- ference and the consequent selection dm’ing 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 aU kinds are inherited equally by the males and females ; we might therefore expect that with man- kind 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 modified, as each has its own standard of beauty. 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 586 The Descent of Man. Part III. 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. Ko excuse is needed for treating this subject in some detail ; for, as the German philo- sopher 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.” ^ There is, however, reason to believe that in certain civilised and semi-civilised nations sexual selection has effected some- thing 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 beau- tiful 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 chiefly due to their better food and manner of life. 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.” * Here is a more curious case ; the priestesses ' ‘Schopenhauer and Darwinism,’ &c. 1822, p. 393), who attributes in ‘Journal of Anthropology,’ Jan. the beauty of the upper classes in 1871, p. 323. England to the meu having long '■* These quotations are taken from selected the more beautiful women. I.awrence Lectures on Physiology,’ Chap. XX, Man — Checks to Sexual Selection. 587 •who attended the temple of Venus Erycina at San-Giuliano in Sicily, -were selected for theii’ beauty out of the whole of Greece ; they -were not vestal -virgins, and Quatrefages,® who states the foregoing fact, says that the women of San-Giuliano are now famous as the most beautiful in the island, and are sought by artists as models. But it is obvious that the evidence in all the above cases is doubtful. The following case, though relating to savages, is well worth giving from its curiosity. Mr. Winwood Eeade 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 youi’ women ?” The Jollof answered, “ It is very easily explained : it has always “ been our custom to pick out our worse-looking 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 long-continued elimination of the ugly women is not so surprising as it may at first appear ; for I have elsewhere shewn * that negroes fully appreciate the importance of selection in the breeding of their domestic animals, and I could give from Mr. Eeade additional evidence on this head. The Causes which prevent or check the Action of Sexual Selection with Savages. — The chief causes are, first, so-called communal marriages or promiscuous intercourse ; secondly, the consequences of female infanticide ; thirdly, early betrothals ; and lastly, the low estimation in which women are held, as mere slaves. These four points must be considered in some detail. 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 an- other. The licentiousness of many savages is no doubt astonish- ing, but it seems to me that more e-vidence is requisite, before we fully admit that their intercourse is in any case promiscuous. Nevertheless all those who have most closely studied the subject,® ’ ‘ Anthropologic,’ ‘ Revue des Cours Scientifiques,’ Oct. 1868, p. 721. ■* ‘ The Variation of Animals and Plants under Domestication,’ vol. i. p. 207. ’ Sir J. Lubbock, ‘The Origin of Civilisation,’ 1870, chap. iii. especi- 588 Past III. The Descent of Man. 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, in- cluding 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, ex- pressed 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 duiing the breeding-season 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 sufiBces for the work of sexual selection. But I know that some of the writers above referred to, imply by the term mannage, a recog- nised 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 cliild 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 ally pp. 60-67. 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 licentious- ness of savages at the present time. Mr. L. H. Morgan, in his interesting memoir on the classificatory system of relationship (‘ Proc. American Acad, of Sciences,’ vol. vii. Feb. 1868, p. 475), concludes that poly- gamy and ail forms of marriage during primeval times were essen- tially unknown. It appears also, from Sir J. Lubbock’s work, that Bachofen likewise believes that communal interccurse originally prevailed. Ohap. XX. Man — Checks to Sexual Selection. 589 tribe alone, to the exclusion even of tlie mother. It seema 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 abso- lutely 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 httle whether the unions last for hfe or only for a season. 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 widely-extended habit of exogamy — ^that 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,® 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 • Address to British Association dition r.f the Lower Races of Man » On the Social and Religious Con- 1870, p. 20. ' 590 The Descent of Man. Part III. intelligible, if we admit that promiBCuous intercourse was the aboriginal, and therefore long revered custom of the tribe.’ 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'Lennau, and Sir J. Ijubbock, yet from the foregoing and several other lines of evidence it seems probable® that the habit of marriage, in any strict sense of the word, has been gi-adually developed ; and that almost promiscuous or very loose intercourse was once ex- tremely common throughout the world. Nevertheless from the strength of the feeling of jealousy aU through the animal kingdom, as weU as from the analogy of the lower animals, more particularly of those which come nearest to man, I cannot beheve 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 ape-hke creatme. With the existing Qiradrumana, 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 or ang seems to afford an instance. Several kinds, for example some of the Indian and American monkeys, are strictly monogamous, and associate all the year roimd with their wives. Others are poly- gamous, for example the gorilla and several American species, and each family lives separate. Even when this occurs, the families inliabiting the same distinct ai’e 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, hve associated in a body, as with several species of baboons.® 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 ' ‘Origin of Civilisation,’ 1870, p. 8G. In the several works above quoted, there will be found copious evidence on relationship through the females alone, or with the tribe ilone. ® Mr. C. Staniland Wake argues strongly (‘ Anthropologia,’ March, 1874, p. 197) against the views held oy these three writers on the former prevalence of almost promiscuous mtercoursc; and he thinks that the classificatory system of relationship can be otherwise explained. ® Brehm (‘ Illust. Theirleben,’ B. i. p. 77) s.ays Cynocephalm hama- dryas lives in great troops contain- ing twice as many adult females as adult males. See Rengger on Ame- rican polygamous species, and Owen (‘Anat. of Vertebrates,’ vol. iii. p. 746) on American . monog.amous species. Other references might be added, GnAP. XX. Man — Checks to Sextial Selection. 59T 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 suffice for sexual selection. 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.” The younger males, being thus expelled and wandering about, would, when at last successful in finding a partner, prevent too close interbreeding within the limits of the same family. 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,” “ 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 poly- gamous 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 promiscuous intercourse, I will not pretend to conjecture. Infanticide. — This practice is now very common throughout the world, and there is reason to believe that it prevailed much more extensively during former times.** Barbarians find it Dr. Savage, ia ‘ Boston Journ.ll ** Mr. M'Lennan, ‘Primitive of Nat. Hist.’ vol. v. 1845—47, p. Marriage,’ 1865. See especially on 423. exogamy and infanticide, pp. 130; “ ‘Prehistoric Times,’ 1869, p. 138, 165. 424. 592 The Descent of Man. Paiit III. 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 Poly- nesian 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*^ prevails the struggle for existence will be in so far less severe and all the members of the tribe wiU 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, tbe 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 cnrious customs and ceremonies, of which Mr. M‘Lennan has given an interesting account. In our own marriages the “ best man ” seems origin- ally 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. ” Dr. Gerland (‘ Ueber das Aus- sterben der Naturvolker,’ 1868) has collected much information on in- fanticide, see especially s. 27, 51, 54. Azara Voyages,’ &c. 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 test. Chap. XX. Man — Checks to Sextial Selection. 593 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 power of sexual selection in differentiating the tribes. 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 Jlr. McLennan boheves, prevailed almost universally ; but this latter conclusion is doubted by Mr. IVIorgan and Sir J. Lubbock.** 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 acceptiog 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.*'* A very ugly man m these cases would perhaps altogether fail in getting a wife, or get one later in hfe ; but the handsomer men, although more successful in obtaining wives, would not, as far as wo can see, leave more offspring to inherit their beauty than the less handsome husbands of the same women. Early Betrothals and Slavery of 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 handsomest slaves according to their standard of beauty. 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 ‘ Primitive Marriage,’ p. 208 ; polyandry. Sir J. Lubbock, ‘ Origin of Civilisa- Azara, ‘Voyages,’ &c. tom. ii. tion,’ p. 100. See also Mr. Morgan, pp. 92-95, Colonel Marshall, loo. cit., on the former prevalence of ‘Amongst the Todas, p. 212. 2 Q 594 The Descent of Man. Pakt III. wMcli savages are exposed, and some of their habits, are favour- able 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,^ and generally marry whilst young. Consequently they must be subjected to occasional hard struggles for existence, and the favoured indi- viduals 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 hfe, and in defend- ing their females, as well as their offspring, from enemies of all kinds. At this early period the ancestors of man would not bo 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 offsijring ; and consequently they would not have practised female infanticide. Women would not have been thus rendered scarce, and poly- andry 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 stepping-stone to communal marriages or almost pro- miscuous intercourse ; though the best authorities believe that this latter habit preceded polyandry. During primordial times there would bo 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 weU as the males were per- mitted 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, Burch ill says (‘Travels in S. Azara (‘Voyages dans I’Amdrique Africa,’ vol. ii. 1824, p. 58), that Merid.’ tom. ii. 1809, p. 21) makes among the wild nations of Southern precisely the same remark in regard Africa, neither men nor women ever to the wild Indians of South Ame- ])ass their lives in a state of celibacy, rica. Chap, XX. Man — Mode of Sexual Selection. 595 and all the offspring, as far as that was possible, would be reared ; so that the struggle for existence would be periodically ex- cessively 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 than at the present day, though probably not yet wholly lost. The Manner of Action of Sexual Selection xcith, ManJcind. — With primeval men 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 in- fanticide, early betrothals, &c. The strongest and most vigorous men,— those who could best defend and himt for their famihes, 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,^'^ “ 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, orna- ments, 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 inex- plicable 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 ” ‘Anthropological Review,’ Jan. 1870, p. xvi- 2 Q 2 596 Part 111. The Desce7tt of Man. 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 imconscious selection during a long series of generations — that is, the preservation of the most approved individuals — ■without 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. Each breeder has impressed, as Von Nathusius well expresses it, the character of his o^wn mind — his o^wn taste and judgment— on his animals. What reason, then, can be assigned why similar results should not follow from the long-continued selection of the most admired women by those men of each tribe, who were able to rear the gi-eatest 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 aU 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 occm’red, each isolated tribe would form for itself a slightly different standard of beauty ; 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 less increased. 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 semi-human 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 ‘ The Variation of Animals and Plants under Domestication,’ vol. ii. pp. 210-217. 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 translat. p. 278. Chap. XX. Man — Mode of Sextcal Selection. 597 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 orna- mented 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 Ehesus 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 sur- prising 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 dehght in deco- ratiug 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 succes- sive 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 then- 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 gamed 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 evidence as I have been able to collect. Heame describes how a woman in one of the tribes of Arctic 598 The Descent of Man. Part III. 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 Abiponos, 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 pai-ents “ 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 tho 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 “Jiei' : 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 of North-Eastern Asia. 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 Eev. 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 Kafii-s, 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 “ ho would dispose of a cow.” Amongst the degraded Bush- men of S. Africa, “ when a girl has grown up to womanhood Chap. XX. Man — Mode of Sexual Selection. 599 “ without haTing been betrothed, which, however, does not often “ happen, her lover must gain her approbation, as well as that of “the parents.”-® Mr, Winwood Eeade 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 faithful attachments.” Additional cases could be given. 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 dhection, 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 well- endowed pairs would commonly rear a larger number of offepring than the less favoui'ed. 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 to have occui’red, especially during the earlier periods of our long history. W e will now examine a little more closely some of the charac- ters 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 -® Azara, ‘Voyages,’ &c. tom. ii. p. 23. DobrizhofFer, ‘An Account of the Abipones,’ vol. ii. 1822, p. 207. Capt. Musters, in ‘Proc. E. Geograph. Soc.,’ vol. .vv. p. 47. Williams on the Fiji Islanders, as quoted by Lubbock, ‘Origin of Civilisation,’ 1870, p. 79. On the Fuegians, King and FitzRoy, ‘Voy- ages of the Adventure and Beagle,’ vol. ii. 1839, p. 182. On the Kal- mucks, quoted by M'Lennan, ‘Pri- mitive Marriage,’ 1865, p. 32. On the Malays, Lubbock, ibid. p. 76. The Rev. J. Shooter, ‘On the Kafirs of Natal,’ 1857, pp. 52-60. Mr. D. Leslie, ‘Kafir Character and Customs,’ 1871, p. 4. On the Bush-men, Burchell, ‘Travels in S. Africa,’ vol. ii. 1824, p. 59. On the Koraks by McKennan, as quoted by Mr. Wake, in ‘ Anthropologia,’ Oct. 1873, p. 75. 6oo Part III The Descent of Man. respects. These characters -will therefore probably have beoE 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 faculties of man have likewise been already discussed. Absence of Hair on the Body, and its Development on the Face and Head. — 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 aU countries are glad to larotect 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 divestetl of hair through natural selection. 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 some- times, as with the male mandrill and female rhesus, much more vividly in the one sex than in the other, especially dui-mg the breeding-season. 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, how- ever, appears to have been removed, not for the sake of nudity, but that the colour of the skin may be more fully displayed. So ** ‘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 hair- less condition of the skin as coming under this head. The Rev. T. K. Stebbing, in commenting on this view (‘ Transactions of Devonshire Assoc, for Science,’ 1870) remarks, that had Mr. Wallace “employed “his usual ingenuity on the ques- “tion 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.’’ Chap. XX. Man — Absence of Hair. 6oi again with many birds, it appears as if the head and neck had been divested of feathers through sexual selection, to exhibit the brightly-coloured skin. 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 semi-human ancestors who were first divested of hah’, 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 bh’ds, 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 ape-hke 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 shghtly injurious character should have been thus acquired ; for we know that this is the case with the plumes of certain bu’ds, and with the horns of certain stags. 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 off- spring of both sexes.^^ Some races are much more hau-y than others, especially the males ; but it must not be assumed that the more haii-y 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 hau-iness 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 ‘The Valuation of Animals and Plants 1868, p. 327. under Domestication,’ vol. ii 602 Part llf. The Descent of Man. negroes, who have been reared during several generations in the United States, and possibly with the Ainos, who inhabit the northern islands of the Japan archipelago. But the laws of inheritance are so complex than 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 bo remarkable.®^ 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 them 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®® 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 almosi. completely divested of hair. Even the colour of our beards seems to have been inherited from an ape-like progenitor ; for when ‘ Investigations into Military .mJ 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 be- “ tween the white and the black “ races in this respect.” It is, how- ever, certain that negroes in their na- tive and much hotter land of Africa, have remarkably smooth bodies. It should be particularly observed, that both pure blacks and mu- lattoes were included in the above enumeration ; and this is an unfor- tunate circumstance, as in accordance •vrith 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 ape- like progenitors. “■' Hardly any view advanced in this work has met with so much disfavour (see for instance, Spengel, ‘ Die Fortschritte des Darwinismus,’ 1874, p. 80) as the above explana- tion 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 foots shewing that the nudity of the skin is to a certain extent a secondary sexual character in man and in some of the Quad- rumana. ‘ Ueber die Richtung der Ilaare am Menschlichcn Kbrper,' in Muller’s ‘Archiv filr Anat. und Phys.’ 1837, s. 40. Chap. XX. Beards, 603 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 gi’eat variability in different races, and even within the same race ; for this indicates reversion, — long lost characters being very apt to vary on re-appearance. 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 feeUngs, 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 long-continued habit of eradicating the hair may have produced an inherited effect. Dr. Brown-Sequardhas 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^“ 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.^^ Nevertheless with man- kind, the habit of eradicating the beard and the hairs on the body would probably not have arisen until these had already become by some means reduced. 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^® states that in the human foetus the hair on the face dming the fifth month is longer than that on the head; and this indicates that our semi-human progenitors were not furnished with long tresses, which must therefore have been a late acquisition. This is likewise indicated by the extra- ordinary difference in the length of the hair in the different races ; in the negro the hair forms a mere curly mat ; with us ‘ On the ta.l-feathers of Momo- Some distinguished ethnologists, tus’ ‘ Proc. Zoolog. Soc.,’ 1873, p. amongst others M. Gosse of Geneva, 429. believe that artificial modifi3ation.s Mr. Sproat has suggested of the skull tend to be inherited. (‘ Scenes and Studies of Savage -* ‘ Ueber die Richtung,’ ibid. s. Life,’ 1868, p. 25) this same view. 40. 6o4 TJi£ Descent of Man. Paet III. 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. Colour of the Skin. — 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 occtUTed in innumerable instances with the lower animals. It seems at first sight a monstrous supposition that the jet-blackncss of the negi’o should have been gained through sexual selection ; but this view is supported by various analogies, and we know that negi-oes 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 minature of Fithecia satanas with his jet black skin, white rolhng 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 fm’, and the ornamental tufts about the head, have all been acquiiud 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 have occurred at a very early period in the history of man. Chap. XX. Summary on Man. 605 Summary. — ■'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 subse- quently 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 ofispring. As far as the extreme intricacy of the subject permits us to judge, it appears that our male ape-like 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 acquired sweeter voices and become more beautiful than men. It deserves attention that with mankind the conditions wero 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 as yet any record, the races of man had ab-eady come to differ nearly or quite as much as they do at the present day. 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 6o6 Part III. The Descent of Man. 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 hail' 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, sexual selection has been the most efficient. CHAPTEE XXI. &ENBEAL Summary and Conclusion. Main conclusion that man is descended from some lower form — Manner of development — Genealogy of man — Intellectual and moral faculties — Sexual selection — Concluding remarks. A BREEP summary will be sufficient to recall to the reader’s mind the more salient pomts in this work. Many of the views which have been advanced are highly speculative, and some no doubt wih 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 at the same time opened. 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 fom. 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, — Chap. XXI. General Summary. 607 are facts which cannot be disputed. They have long been Imown, but until recently they told us nothing with respect to the origin of man. Now when viewed by the Light of our know- ledge of the whole organic world, their meaning is unmistakable. The great principle of evolution stands up clear and firm, when these groups of facts are considered in connection with others, such as the mutual affinities of the members of the same gi’oup, 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 dog — the construction of his skuU, limbs and whole frame on the same plan with that of other mammals, independently of the uses to which the parts may be put — the occasional re-appearance of various structures, for instance of several muscles, which man does not normally possess, but which are common to the Quadrumana — and a crowd of analogous facts— all point in the plainest manner to the conclusion that man is the co-descendant with other mammals of a common progenitor. We have seen that man incessantly presents individual differ- ences 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 the lower animals. In both cases similar laws of inheritance prevail. Man tends to increase at a greater rate than his means of subsistence ; con- sequently he is occasionally subjected to a severe struggle for existence, and natural selection will have effected whatever lies within its scope. A succession of strongly-marked variations of a similar nature is by no means requisite ; slight fluctuating differences in the individual suffice for the work of natural selec- tion ; 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 long-continued 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 6o8 The Descent of Man. Part III, importance, some indeed of considerable importance, have been gained throngb sexual selection. No doubt man, as well as every other animal, presents structures, which seem to our limited knowledge, not to bo now of any service to him, nor to have been so formerly, either for the general conditions of hfe, 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 disnsf! of parts. We know, however, that many strange and strongly- marked peculiarites 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 modi- fications, especially through the study of monstrosities: hence the labours of experimentalists, such as those of M. Camille Dareste, are full of promise for the futiiro. 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 exciting organic changes of many kinds. 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, sub- species. Some of these, such as the Negro and European, are so distinct that, if specimens had been brought to a naturah'st 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 pro- genitor 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 well-fitted. 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 xmconsciously forms a new strain. So with respect Chap. XXI. General Stimmary. 609 to modifications acquired independently of selection, and due to variations arising from the nature of the organism and the action of the sru-rounding 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 ho 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 ha^ve been classed amongst the Quadrumana, as surelv as the still more ancient progenitor of the Old and New World monkeys. The Quadrumana and all the higher mammals are prebahly derived from an ancient marsupial animal, and this through a long line of diversified forms, from some amphibian-like creature, and this again from some fish-like 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 branchise, 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 larvae of the existing marine Ascidians than any other known form. The high standard of our intellectual powers and moral dis- position is the greatest difiBculty which presents itself, after wo liave 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 scale-insect, 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 all-important to him, even at a very OIO The Descent of Man. Part III, remote period, as enabling him to invent and use language, to make weapons, tools, traps, &c., whereby witli the aid of liis social habits, he long ago became the most dominant of all living creatures. A great stride in the development of the intellect will have followed, as soon as the half-art and half-instinct of language came into use ; for the continued use of language will have reacted on the brain and produced an inherited effect ; and thi.s again will have reacted on the improvement of language. As Mr. Chauncey Wright' 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 ratiocinatior. abstraction, self-consciousness, &c., probably follow from the con- tinued improvement and exercise of the other mental faculties. 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 im- portant elements are love, and the distinct emotion of sympathy. Animals endowed with the social instincts take pleasui'e 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 Ineir motives — of 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 ever-present nature of the social instincts ; secondly, from man’s appreciation of the appro- bation and disapprobation of his fellows ; and thirdly, from the high activity of his mental faculties, with past impressions ex- tremely vivid ; and in these latter respects he difters from the lower animals. Owing to this condition of mind, man cannot * ‘On the Limits of Natural Selection,’ in the ‘North American Keview,’ Oct. 1870, p. 295. •I Chap. XXI. Gejieral Simimary. 6ir aToid 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 ever- present social instincts ; and he then feels that sense of dissatis- faction 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 passing temptation of hunting it. 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 desh-es by words, which thus become a guide to the aid requmed and bestowci The motive to give aid is hkewise 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 greatest-happiness 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 indi- vidual, and on the general good, are perceived ; and then the self- regarding virtues come within the scope of public opinion, and receive praise, and their opposites blame. But wth 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 heavy crimes. The moral faculties are generally and justly esteemed as of higher value than the intellectual powers. But wo 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 2 R 2 6i2 , The Descent of Mail. Past HI. eveiy liuinan being. ISTo 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 strengthen.s the habit of recalling and comparing past impressions, will make the conscience more sensitive, and may even somewhat compensate for weak social affections and sympathies. 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 virtuoms tendencies may be inherited. With the more civilised races, the conviction of the existence of an all-seeing 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 foxmdation 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 lower animals, through natural selection. 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 all-pervading spiritual agencies seems to be universal ; and apparently follows from a considerable advance in man’s reason, and from a stiU 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 thiis 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 long-continued culture. 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 ; CuAi'. XXL General Summary. 613 but ai'giunents derived from the primeval beliefs of savages ai’e, 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 traco 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. * I am aware that the conclusions arrived at in this work will be denounced by some as highly ii’religious; 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 bh-th 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 such events, have all been ordained for some special purpose. 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, wo come to the Arthropoda and Vertebrata, even to the lowest classes in these two great Sub-Kingdoms, sexual selection has cfiected much. 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, - The Kev. J. A. Picton ejives a discussion to this cfT’ect in his ‘New Theories and the Old Faith, 1870. 6i4 The Descent of Man. Pakt iir. and are endowed with the requisite qualities of courage and pugnacity. They are provided, cither exclusively or in a much higher degree than the females, with organs for vocal or instru- mental music, and with odoriferous glands. They are ornamented with infinitely diversified appendages, and Avith the most brilliant or conspicuous colours, often arranged in elegant patterns, whilst the females are unadorned. "Whon the sexes differ in more important structui-es, it is the male which is provided with special sense-organs for discovering the female, with locomotive organs for reaching her, and often uith 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 breeding-sea.son. 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 oflspring through- out 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 lands ; in the one it is between the 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 agi'eeable 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 CuAP. XXI. General Stivimary. 6rs sani6 SGXj or to both ; as well as the age at which they shall be •leveloped. It appears that Yariatious arising late in life are commonly transmitted to one and the same sex. Variability is the necessai-y 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 propaga- tion 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 bo 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 strongly-marked diffexences must be in some manner highly important; and wo know that they have been acquired in some instances at the cost not only of inconvenience, but of exposure to actual danger. 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 breeding-season. 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 aU this should be purposeless. Lastly we have distinct evidence with some quad- rupeds and buds, that the individuals of one sex are capable of feeling a strong antipathy or preference for certain individuals of the other sex. 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, charac- terised 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 6i6 The Descent of Man. Paet III. larger mimber of offspring to inherit their superiority in oma- ments or other charms than the less attractive males; but 1 liave 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 victorious males. Although we have some positive evidence that birds appre- ciate bright and beautiful objects, as with the bower-bii-ds 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 bo 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 male, remained widows during a whole season rather than pair with another bii-d. Nevertheless I know of no fact in natural history more wonder- ful than that the female Argus pheasant should appreciate the exquisite shading of the ball-and-socket ornaments and the elegant patterns on the wing-feathers 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 coiu’tship and at no other time iu 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 appre- ciating such ornaments. I differ only in the conviction that the male Argus pheasant acquired his beauty gradually, through the preference of the females dui-ing many generations for the more highly ornamented males ; the msthetic capacity of the females having been advanced through exej’cisc or habit, just as our own taste is gradually improved. In tho male thi-ough 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 tho wonderful ball-and-socket ornaments; and it is probable that they were actirally thus developed. Everyone who admits the princiifle of evolution, and yet feels great difficulty in admitting that female mammals, birds, CuAP. XXI. General Summary. 617 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 nerve-cells 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 same degree. The reader who has taken the trouble to go through the several chapters devoted to sexual selection, wiU 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 superfluoris 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 lowly-organised 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. Comagc, 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 ho is in so far superior to them that he highly values mental charms and virtues. On the other hand ho 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. Botlv sexes ought to rcfi'ain from marriage if they are in any marked degree inferior in body or mind; but such hopes are Utopian and 6iS The Descent of Man. Pai'.t hi. ■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 in- heritance are better understood, we shall not hear ignorant members of our legislature rejecting with scorn a plan for ascertaining -n^hether or not consanguineous marriages are injurious to man. 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 .*till 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 e-vils, 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, &c., than through natural selection; though to this latter agency may bo 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 regz-et to think, be highly distasteful to many. But there can hardly be a doubt that we are descended from barbarians. The aston- ishment which I felt on first seeing a pai'ty of Feugians on a wild and broken shore will never be forgotten by me, for the reflection at once rushed into my mind— such were our ancestors. These men were absolutely naked and bedaubed with paint, their long hair was tangled, their mouths frothed with excite- ment, and their expression was wild, startled, and distrustful. Chap. XXL General Summary. 619 They possessed kai-dly 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 ha.? 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. Tor 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, cai’ried away in triumph his young comrade from a crowd of astonished dogs — as from a savage who delights to torture his enemies, offers up bloody sacrifices, practises infanticide without remorse, treats his wives like slaves, knows no decency, and is haunted by the grossest superstitions. 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 god-hke intellect which has penetrated into the movement.s and constitution of the solar system — with all these exalted powers — Man still bears in his bodily frame the indelible stamp of his lowly origin. ( 620 ) SUPPLEMENTAL NOTE ON SEXUAL SELECTION IN RELATION TO MONKEYS, (Reprinted from Nature, November 2, 1876, 18.) In the discussion on Sexnal Selection in my ‘ Descent of Man,’ no case interested and perplexed me so much as the brightly- coloured 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 bright-red hinder end than that a peacock should display his magnificent tail. I had, however, at that time no evidence of monkeys exliibiting this part of their bodies during their conrtship ; 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 Job. von Kscher, 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 shows that the author is a careful and acute observer. In this article there is an account of the behavioiu’ of a young male mandrill when he fii’st beheld himself in a looking-glass, and it is added, that after a time he tui-ned round and presented his red hinder end to the glass. Accordingly I wrote to Herr J. von Eischer 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 him- self at fiii’st perplexed by the above action, and was thus led carefully to observe several individuals of various otlier species of inonkeys, which he has long kept in his house. He linds that 621 Supplemental Note. not only the mandi-ill {Cynocephalus mm-mon') but the drill (6. leucophoe.ua) and three other kinds of baboons (C. hamadryas, sphinx, and balouin), also Cynopithecus niger, sindi Macacus rhesus and nemestrinus,taxn this part of their bodies, which in all these species is more or less brightly coloured, to him when they arc Ijleased, and to other persons as a sort of greeting. He took pains to cure a ilfacacws 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 fii-st 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 spon- taneously 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 look- ing-glass (viz. the mandrill, di’ill, Cynopithecus niger, Macacus rhesus and nemestrinus) acted as if them 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 mot at all coloured. This remark applies to many individuals of Macacus cynomolgus and Cercocebus radiatus (which is closely alhed 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 622 The Descent of Man. that Ids 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 eertaia 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 gur- gelnden Tonen die stark gerothete Sitzflache zeigtc, was ich friiher nie an diesem Thier bemerkt hatte. Beim Aublick dieses Gegenstandes erregte sich das Mannchen sichtlich, denn es polterte heftig an den Staben, ebenfalls gui’gelnde Laute aus- stossend.” 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 aU surprising that it should have been this part of then- 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, thi’ough 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 atti'action during the season of love, and that the leks, or great congregations of the black grouse, 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 of the year. 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 Supplemental Note. 623 tlie 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 liind 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 j)rinciple 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 brillant colourmg. 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 orna- ments. We may infer from what we see of the variation of animals tmder domestication, that the above several ornaments of the mandrill were gradually acquired by one individual vary- ing 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 foi-mer, 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 unifonnly, 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 iimbs ; 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 624 'J-'he Descent of Man. ages have intemigrated and intercrossed, and where, moreover, the variations will probably not have been identically the same, sexual selection might causo 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 closely-allied birds inhabiting distinct countries, of which the young and the females cannot be distin- guished, whilst the adult males differ considerably, and this may be attributed with much probability to the action of sexual selection. ABBorr. AQHIOX. A. Abbot, C., on the battles of seals, 500. Abductor of the fifth metatarsal, presence of, in man, 42. Abercrombie, Dr., on disease of the brain affecting speech, 88. Abipones, marriage customs of the, 598. Abou-Simbol, caves of, 168. Abortion, prevalence of the practice of, 46. Abstraction, power of, in animals, 83. Acalles, stridulation of, 306. Acanthodactylus capensis, sexual dif- ferences of colour in, 357. Accentor modular is, 473. Acclimatisation, difference of, in dif- ferent races of men, 167. Achotida:, stridulation of the, 282, 283, 285 ; rudimentary stridulating organs in female, 288. Acilius sulcatus, elytra of the female, 276. Acomus, development of spm’s in the female of, 450. Acridiidoe stridulation of the, 282, 286 ; rudimentary stridulating or- gans in female, 288. Acromio-basilar muscle, and quad- rupedal gait, 42. Acting, 178. Actinia:, bright colours of, 260. Adams. Mr., migration of birds, 108 ; intelligence of nut-hatch, 418 ; on the Bomhydlla carolinensis, 461. .\dmiral butterfly, 312. Adoption of the young of other ani- mals by female monkeys, 70. Advancement in the organic scale. Von Baer’s definition of, 164. Aeby, on the difierence between the skulls of man and the quadrumana, 149. jEsthetic faculty, not highly deve- loped in savages, 93. Affection, maternal, 70 ; manifestation of, by animals, 70 ; parental and filial, partly the result of natural selection, 105 ; mutual, of birds, 410; shewn by birds in confine- ment, for certain persons, 411, Africa, probably the birthplace of man, 155 ; South, crossed popula- tion of, 174 ; South, retention of colour by the Dutch in, 193 ; South, proportion of the sexes in the but- terflies of, 250 ; tattooing practised in, 574 ; Northern, coiffure of natives of, 575. Agassiz, L., on conscience in dogs, 103; on the coincidence of the races of man with zoological pro- vinces, 169 ; on the number of species of man, 174 ; on the court- ship of the land-snails, 262 ; on the brightness of the colours of male fishes during the breeding season, 340 ; on the frontal protuberance of the males of Gcophagus and Cichla, 340, 345 ; male fishes hatching ova in their mouths, 345 ; sexual differences in colour of chro- mids, 345 ; on the slight sexual differences of the South Americans, 561 ; on the tattooing of the Ama- zonian Indians, 676. Age, in relation to the transmission of characters in birds, 463 ; va- i-iation in accordance with, in birds, 484. Agalceus phoeniccus, 22b, 4:\Q. Ageronia feronia, noise produced bv, 307. Agrion, dimorphism in, 290. 2 S 626 AGUION. INDEX. ANTELOPE. Agrion Jlamburii, sexes of, 290. Agrionidffi, difference in the sexes of, 290. Agrotis exclamationis, 316. Ague, tertian, dog suffering from, 8. Aithuras polytinus, young of, 487. Ainos, hairiness of the, 560. Albino birds, 419. Alca torda, young of, 486. Alecs pahnata, 515. Alder and Hancock, MM., on the nudi-branch mollusca, 264. Allen, J. A., vigour of birds earliest hatched, 212, 213; effect of dif- ference of temperature, light, &c., on birds, 225 ; colours of birds, 422 ; on the relative size of the se.xes of Callorhimis ursinus, 515 ; on the mane of Otaria jubata, 521 ; on the pairing of seals, 523 ; on sexual differences in the colour of bats, 534. —— S., on the habits of Hoplo- pterus, 366 ; on the plumes of herons, 391 ; on the vernal moult of Herodias bubulcus, 393. Alligator, courtship of the male, 221, 351 ; roaring of the male, 567. Amadavat, pugnacity of male, 366. Amadina Lathami, display of plumage by the male, 402. castanotis, display of plumage by the male, 402. Amazons, butterflies of the, 250 ; fishes of the, 343. America, variation in the skulls of aborigines of, 26 ; wide range of aborigines of, 169 ; lice of the natives of, 170; general beardless- ness of the natives of, 560. , North, butterflies of, 250 ; Indians of, women a cause of strife among the, 561 ; Indians of, theii- notions of female beauty, 577, 580. , South, character of the natives of, 168 ; population of parts of, 173 ; piles of stones in, 179 ; e.x- tinction of the fossil horse of, 191 ; desert-birds of, 490 ; slight sexual difference of the aborigines of, 561 ; prevalence of infanticide in, 592. American languages, often highly artificial, 91. Americans, wide geographical range of, 29; native, variability of, 174; and negroes, difference of, 197 ; aversion of, to hair on the face, 580. Ammopltila, on the jaws of, 275. Ammoiragus tragelaphus, hairy fore- legs of, 531, 533. Amphibia, affinity of, to the ganoid fishes, 159 ; vocal organs of the, 566. Amphibians, 165, 348 ; breeding whilst immature, 485 Amphioxus, 159. Amphipoda, males sexually mature while young, 485. Amunoph III., negro character of features of, 168. Anal appendages of insects, 275. Analogous variation in the plumage of birds, 385. Anas, 462. acuta, male plumage of, 393. boschas, male plumage of, 393. histrionica, 484. punctata, 374. Anastomus oscitans, sexes and young of, 486 ; white nuptial plumage of, 492. Anatidaj, voices of, 374. Anax junius, differences in the sexes of, 290. Andaman islanders, susceptible to change of climate, 188. Anderson, Dr., on the tail of Macacus brunneus, 59 ; the Bufo sVdmincu- sis, 349 ; sounds of Echis carinata, 353. Andrcena fulva, 292. Anglo-Saxons, estimation of the beard among the, 581. Animals, domesticated, more fertile than wild, 45 ; cruelty of savagc^ to, 118; characters common to man and, 146 ; domestic, change of breeds of, 596. Annelida, 264 ; colours of, 265. Anobiun tessellatum, sounds produced by, 306. Anolis cristatcUus, male, crest of, 354 ; pugnacity of the male, 354 ; throat- pouch of, 354. Anser canadensis, 416. cygnoides, 415 ; knob at the base of tile beak of, 426. hyperboreus, whiteness of, 492. Antelope, prong-horned, horns of, 234. ANTELOPES. INDEX. ARDEA. 627 Antelopes, generally polygamous, 217 ; horns of, 234, 604 ; canine teeth of some male, 502 ; use of horns of 509 ; dorsal crests in, 530 ; dew- laps of, 531 ; winter change of two species of, 543 ; peculiar markings of, 543. Antennae, furnished with cushions in the male of Fentlie, 276. A nthidium manicatum, lai-ge male of, 279. Anthocharis cardamines, 308, 312; sexual difference of colour in, 322. genutia, 312. Sara, 312. Anthophora acervorum, large male of, 279. retusa, difference of the sexes in, 292. Anthropid®, 152. Anthus, moulting of, 392. Antics of birds, 380. Antigua, Dr. Nicholson’s observations on yellow fever in, 195. Antilocapra americana, horns of, 234, 504, 507. Antilope hezoartica, horned females of, 505, 506, 507 ; sexual difference in the colour of, 535. ■ Dorcas and euchore, 504. euchore, horns of, 509. montana, rudimentary canines in the young male of, 514. nigar, sing-sing, caama, and gor- gon, sexual differences in the colours of, 536. oreas, horns of, 234. saiga, polygamous habits of, 217. strepsiceros, horns of, 234. ■ subgutturosa, absence of sub- orbital pits in, 529. Antipathy, shewn by birds in confine- ment, to certain persons, 411. Ants, 147 ; large size of the cerebral ganglia in, 54 ; soldier-, large jaws of, 63 ; playing together, 69 ; memory in, 74 ; intcommunication of, by means of the antenn®, 89 ; habits of, 147 : difference of the sexes in, 292 ; recognition of each other by, after separation, 292. White, habits of, 291. Anura, 349. Apatania muliebris, male unknown, 264. Apathus, difference of the sexes in, 292. Apatura Iris, 307, 308. Apes, difference of the young, from the aluit, 8 ; semi-erect attitude of some, 52 ; mastoid processes of, 63 ; influences of the jaw-muscles on the physiognomy of, 54 ; female, destitute of large canines, 63 ; building platforms, 82 ; imitative faculties of, 129 ; anthropomor- phous, 153 ; probable speedy ex- termination of the, 156 ; Gratiolet on the evolution of, 177 ; canine teeth of male, 502 ; females of some, less hairy beneath than the males, 601. long-armed, their mode of pro- gression, 52. Aphasia, Dr. Bateman on, 88. Apis mellijica, large male of, 279. Apollo, Greek statues of, 581. Apoplexy in Cehus Azarx, 7. Appendages, anal, of insects, 276. Approbation, influence of the love of, 109, 116, 131. Aprosmictus scapulatus, 457. Apus, proportion of sexes, 255. Aquatic birds, frequency of white plumage in, 495. Aquila chrysaetos, 408. Arab women, elaborate and peculiar coiffure of, 583. Arabs, fertility of crosses with other races, 171 ; gashing of cheeks and temples among the, 574. Arachnida, 272. Arakhan, artificial widening of the forehead by the natives of, 583. Arhoricola, young of, 468. Archeopteryx, 158. Arctiid®, coloration of the, 314. Ardea asha, rufescens, and cxrulea, change of colour in, 494, 495. cmrulea, breeding in immature plumage, 484. gularis, change of plumage in, 495. herodias, love-gestures of the male, 380. ludoviciana, age of mature plu- mage in, 483; continued growth of crest and plumes in the male of, 485. nycticorax, cries of, 368. 2 s 2 628 ARDEOrjV. INDEX. AUSTRALIA. Ardeola, young of, 468. Ardctta, changes of plumage in, 461. Argenteuil, 22. Argus pheasant, 384, 403, 462 ; dis- play of plumage by the male, .198 ; ocellated spots of the, 428 ; grada- tion of characters in the, 434. Argyll, Duke of, on the physical weakness of man, 63 ; the fashion- ing of implements peculiar to man, 82 ; on the contest in man between right and wrong, 125 ; on the pri- mitive civilisation of man, 143 ; on the plumage of the male Argus pheasant, 398 ; on Urosticte Ben- yamini, 442, 443 ; on the nests of birds, 453. Argynnis, colouring of the lower sur- face of, 314. Aricoris opitus, se-rual differences in the wings of, 277. Aristocracy, increased beauty of the, 586. Arms, proportions of, in soldiers and sailors, 32 ; direction of the hair on the, 151. and hands, free use of, indi- rectly correlated with diminution of canines, 53. Arrest of development, 35, 36. Arrow-heads, stone, general resem- blance of, 179. Arrows, use of, 179. Arteries, variations in the course of the, 26. Artery, effect of tying, upon the lateral channels, 32. Arthropoda, 265. Arts practised by savages, 179. Ascension, coloured incrustation on the rocks of, 263. Ascidia, affinity of the lancelet to, 159 ; tadpole-like larva: of, 159. Ascidians, 262; bright colours of some, 260. Asinus, Asiatic and African species of, 548. tamiopus, 548. Ass, colour-variations of the, 547. Aides, efi'ects of brandy on an, 7 ; absence of the thumb in, 51. beeUehuth, ears of, 15. marginatus, colour of the ruff of, 537 ; hair on the head of, 549. Atcuchus, stridulation of, 306. Ateuchns, cioatricosus, habits of, 300. Athalia, proportions of the sexes in, 254. Atropus pulsatorius, 291. Attention, manifestations of, in ani- mals, 73. Audouin, V., on a hyraenopterous pa- rasite with a sedentary male, 221. Audubon, J. J., on the pinioned goose, 105; on the speculum oi Mcrgus citcullaius, 236 ; on the pugnacity of male birds, 362, 366 ; on Tetrao cupido, 367 ; on Ardea nycticorax, 368 ; on Stumella ludoviciana, 368 ; on the vocal organs of Tetrao cupido, 371 ; on the drumming of the male Tetrao umbeUus, 315', on sounds produced by the nightjar, 376; on Ardea herodias and Cath- artes jota, 380 ; on Mimus poly- glottus, 393 ; on display in male birds, 394 ; on the spring change of colour in some finches, 394 ; recog- nition of a dog by a turkey, 412 ; selection of mate by female birds, 416 ; on the turkey, 411, 412, 419 ; on variation in the male scarlet tanager, 424; on the musk-rat, 542 ; on the habits of Fyranga cestiva, 453 ; on local differences in the nests of the same species of birds, 456 ; on the habits of wood- peckers, 458 ; on Bombycilla caro- linensis, 461; on young females of Tyranga cestiva acquiring male cha- racters, 462 ; on the immature plumage of thrushes, 464; on the immature plumage of birds, 465 ct seq. ; on birds breeding in immature plumage, 484 ; on the growth of the crest and plumes in the male Ardea ludoviciana, 485 ; on the change of colour in some species of Ardea, 494 Audubon and Bachman, M.M., on squirrels fighting, 500 ; on the Canadian lynx, 521. Aughey, Prof., on rattlesnakes, 353. Austen, N.L., on Anolis cristatollus, 354. Australia, not the birthplace of man, 155 ; half-castes killed by the natives of, 170 ; lice of the natives of, 170 ; prevalence of female in- fanticide in, 592. AUSTRALIA. INDEX. liARRINQTON. 629 Australia, South, variation in the skulls of aborigines of, 26. Australians, colour of newborn chil- dren of, 557 ; relative height of the sexes of, 559 ; women a cause ot war among the, 561. Axis deer, sexual difference in the colour of the, 537. Aymaras, measurements of the, 34 ; no grey hair among the, 559 ; hairlessness of the face in the, 561 ; long hair of the, 580. Az.ira, on the proportion of met and women among the Guaranys, 244 ; on Talamedea comuta, 366 ; on the beards of the Guaranys, 561 ; on strife for women among the Guanas, 561 ; on infanticide, 577, 592 ; on the eradication of the eyebrows and eyelashes by the Indians of Para- guay, 580 ; on polyandry among the Guanas, 593 ; celibacy unknown among the savages of South Ame- rica, 594 ; on the freedom of divorce among the Charruas, 598. B. B.abbage, C., on the greater proportion of illegitimate female births, 244. Babirusa, tusks of the, 518. Baboon, revenge in a, 69 ; rage ex- cited in, by reading, 71 ; manifes- tation of memory by a, 74; em- ploying a mat for shelter against the sun, 82 ; protected from punish- ment by its companions, 103. , Cape, mane of the male, 521 ; Hamadryas, mane of the male, 521. Baboons, effects of intoxicating li- quors on, 7 ; eai-s of, 15 ; diversity of the mental faculties in, 27 ; hands of, 50 ; habits of, 51 ; variability of the tail in, 58 ; manifestation of maternal affection by, 70; using stones and sticks as weapons, 81 ; co-operation of, 101 ; silence of, on plundering expeditions, 104; ap- parent polygamy of, 217; poly- gamous and social habits of, 590. Bachman, Dr., on the fertility of mu- lattoes, 171. Baer, K. E. von, on embryonic deve- lopment, 9. Bagehot, W., on the social virtues among primitive men, 117 ; slavery formerly beneficial, 117 ; on the value of obedience, 130 ; on human progress, 132 ; on the persistence of savage tribes in classical times, 183. Bailly, E. M., on the mode of fighting of the Italian buffalo, 508 ; on the fighting of stags, 510. Bain, A., on the sense of duty, 98 ; aid springing- from sympathy, 103 ; on the basis of sympathy, 106 ; on love of approbation, &c., 109 ; on the idea of beauty, 584. Baird, W., on a difference in colour between the males and females of some Entozoa, 260. Baker, Hr., observation on the pro- portion of the sexes in pheasant- chicks, 247. , Sir S., on the fondness of the Arabs for discordant music, 380 ; on sexual difference in the colours of an antelope, 536 ; on the elephant and rhinoceros attacking white or grey horses, 540 ; on the disfigure- ments practised by the negroes, 541 ; on the gashing of the cheeks and temples practised in Arab countries, 574 ; on the coiffure of the North Africans, 575 ; on the perforation of the lower lip by the women of Latooka, 575 ; on the distinctive characters of the coiffure of central African tribes, 576 ; on the coiffure of Arab women, 584. “ Balz ” of the Black-cock, 363, 405. Bantam, Sebright, 211, 238. Banteng, horns of, 505 ; sexual dif- ferences in the colours of the, 536. Banyal, colour of the, 579. Barbarism, primitive, of civilised nations, 143. Barbs, filamentous, of the feathers, in certain birds, 385, 430. Barrage, F., on the Simian resem- blances of man, 3. Barr, Mr., on sexual preference in dogs, 524. Barrington, Daines, on the language of birds, 86 ; on the clucking of the hen, 368 ; on the object of the song of birds, 369 ; on the singing of female birds, 370 • on birdo 630 BAUROW. INDEX. BEDDOE. acquiring the songs of other birds, 370; on the muscles of the larynx in song birds, 371 ; on the want of the power of song by .^emale birds, 450. Barrow, on the widow-bird, 403. Bartels, Dr., supernumerary mamma: in men, 37. Bartlett, A. D., period of hatching of birds’ eggs, 165 ; on the tragopan, 220 ; on the development of the spurs in Crossoptilon auritum, 236 ; on the fighting of the males of Plectropterus gambensis, 364 ; on the knot, 391 ; on display in male birds, 394 ; on the display of plu- mage by the male Folyplectron, 396 ; on Crossoptilon auritum and Phasianus WallicMi, 400 ; on the habits of Lophophorus, 420 ; on the colour of the mouth in Buceros bicornis, 426 ; on the incubation of the cassowary, 478 ; on the Cape Buffalo, 508 ; on the use of the horns of antelopes, 509 ; on the fighting of male wart-hogs, 520 ; on Ammotragus tragelaphus, 531 ; on the colours of Cercopithecus ceplius, 537 ; on the colours of the faces of monkeys, 550 ; on the naked surfaces of monkeys, 600. Bertram, on the courtship of the male alligator, 351. Basque language, highly artificial, 91. Bate, C. S., on the superior activity of male Crustacea, 221 ; on the proportions of the sexes in crabs, 255 ; on the chelse of Crustacea, 266 ; on the relative size of the sexes in ci'ustacea, 268 ; on the colours of Crustacea, 270. Bateman, Dr., tendency to imitation in certain diseased states, 72 ; on Aphasia, 88. Bates, H. W., on variation in the form of the head of Amazonian Indians, 28 ; on the proportion of the sexes among Amazonian but- terflies, 250 ; on sexual differences in the wings of butterflies, 277 ; on the field - cricket, 283 ; on Pyrodes pulcherrimus, 294 ; on the horns of Lamellicorn beetles, 295, 297 ; on the colours of Epicalia:, &c., 309 ; on the coloration of tropical butterflies, 311 ; on the variability of Papilio Sesostris and ChildrcntB, 320 ; on male and fe- male butterflies inhabiting different stations, 321 ; on mimicry, 323 ; on the caterpillar of a Spjhinx, 325 ; on the vocal organs of the um- brella-bird, 374; on the toucans, 492 ; on Brachjurus calvus, 550. Batokas, knocking out two upper in- cisors, 575. Batrachia, 349 ; eagerness of male, 221. Bats, scent-glands, 529 ; sexual dif- ferences in the colour of, 534; fur of male frugivorous, 534. Battle, law of, 144; among beetles, 299 ; among birds, 360 ; among mammals, 500 et seq. ; in nuin, 561. Beak, sexual difference in the forms of the, 359 ; in the colour of the, 383. Beaks, of birds, bright colours ofj 491. Beard, development of, in man, 557 ; analogy of the, in man and the quadrumana, 558 ; variation of the development of the, in different races of men, 559 ; estimation of, among bearded nations, 581 ; pro- bable origin of the, 602. , in monkeys, 150 ; of mammals, 531. Beautiful, taste for the, in birds, 410 ; in the quadrumana, 540. Beauty, sense of, in animats, 92 ; ap- preciation of, by birds, 413 ; in- fluence of, 573, 576 ; variability of the standard of, 596. Beavan, Lieut., on the development of the horns in Cervus Eldi, 234. Beaver, instinct and intelligence of the, 67, 68 ; voice of the, 527 ; castoreum of the, 529. Beavers, battles of male, 500. Bechstein, on female birds choosing the best singers among the males, 368 ; on rivalry in song-birds, 369 ; on the singing of female birds, 370 ; on birds acquiring the songs or other birds, 370; on pairing the canary and siskin, 415 ; on a sub- variety of the monk pigeon, 427 ; on spurred hens, 449. Beddoe, Dr., on causes of difference in stature, 31. BEE-EATER. INDEX. BIRB3. 631 Bee-eater, 371. Bees, 99; pollen-baskets and stings of, 63 ; destruction of drones and queens by, 106 ; female, secondary se.xual characters of, 208 ; propor- tion of sexes, 254; difference of the sexes in colour and sexual selection, 292. Beetle, luminous larva of a, 277. Beetles, 294 ; size of the cerebral ganglia in, 54; dilatation of the fore tarsi in male, 275 ; blind, 294 ; stridulatiou of, 301. Belgium, ancient inhabitants of, 182. Bell, Sir C., on emotional muscles in man, 3 ; “ snarling muscles,” 41 ; on the hand, 51. , T., on the numerical proportion of the sexes in moles, 247 ; on the newts, 348 ; on the croaking of the frog, 350 ; on the difference in the coloration of the sexes in Zootoca vivipara, 357 ; on moles fighting, 500. Bell-bird, sexual difference in the colour of the, 389. Bell-birds, colours of, 492. Belt, Mr., on the nakedness of tropical mankind, 57 ; on a spider-monkey and eagle, 102 ; habits of ants, 147 ; LampyridiE distasteful to mammals, 277 ; mimicry of Leptalides, 325 ; colours of Nicaraguan frogs, 349 ; display of humming-birds, 443 ; on the toucans, 492 ; protective co- louring of skunk, 543. Benevolence, manifested by birds, 411. Bennett, A. W., attachment of mated birds, 411; on the habits of Dro- nucus irroratus, 478. , Dr., on birds of paradise, 396. Berbers, fertility of crosses with other races, 171. Bernida antarctica colours of, 492. Bernicle gander pairing with a Canada goose, 414. Bert, M., crustaceans distinguish colours, 271. Bertillon, M., an-ested development and polydactylism, 37. Bettoui, E., on local differences in the nests of Italian birds, 456. Beyle, M., see Bombet. Bhoteas, colour of the beard in, 558. Bhringa, disciform tail-feathers of, 392. Bianconi, Prof., on structures as ex- plained through mechanical prin- ciples, 24. Bibio, sexual differences in the genus, 280. Bichat, on beauty, 585. Bickes, proportion of sexes in man, 243. Bile, coloured, in many animals, 261. Bimana, 149. Birds, imitations of the songs of other birds by, 73 ; dreaming, 74 ; killed by telegraph wires, 80 ; language of, 86 ; sense of beauty in, 92 ; pleasure of, in incubation, 105 ; male, incubation by, 163; and rep- tiles, alliance of, 165 ; sexual dif- ferences in the beak of some, 208 ; migratory, arrival of the male be- fore the female, 212 ; apparent relation between polygamy and marked sexual differences in, 220 ; monogamous, becoming polygamous under domestication, 220 ; eager- ness of male in pursuit of the fe- male, 221 ; wild, numerical propor- tion of the sexes in, 247 ; secondary sexual characters of, 358 ; differ- ence of size in the sexes of, 362 ; fights of male, witnessed by females, 367 ; display of male, to captivate the females, 367 ; close attention of, to the songs of others, 368 ; ac- quiring the song of their foster- parents, 37 0 ; brilliant, rarely good songsters, 371; love -antics and dances of, 380 ; coloration of, 385 et seq. ; moulting of, 390 et seq. ; unpaired, 407 ; male, singing out of season, 409 ; mutual affection of, 410 ; in confinement, distinguish persons, 411 ; hybrid, production of, 414; Albino, 419; European, number of species of, 422 ; varia- bility of, 422 ; geographical distri- bution of colouring, 422 ; gradation of secondary sexual characters in, 430 ; obscurely coloured, buildi.ig concealed nests, 454 ; young female, acquiring male characters, 462 ; breeding in immature plumage 484 ; moulting of, 484 ; aquatic, 632 niRQDS. INDEX. BLYTH. frequency of white plum.nge in, 493 ; vocal courtship of, 567 ; naked skin of the head and neck in, 601. Birgus latro, habits of, 270. Birkbeck, Mr., on the finding of new mates by golden eagles, 408. Birthplace of man, 155. Births, numerical proportions of the sexes in, in animals and man, 215, 216 ; male and female, numerical proportion of, in England, 242. Bischofif, Prof., on the agreement be- tween the brains of man and of the orang, 6 ; figure of the embryo of the dog, 10 ; on the convolutions of the brain in the human foetus, 11 ; on the difference between the skulls of man and the quadrumana, 149 ; resemblance between the ape’s and man’s, 200. Bishop, J., on the vocal organs of frogs, 350 ; on the vocal organs of corvine birds, 370 ; on the trachea of the Merganser, 374. Bison, American, co-operation of, 101; mane of the male, 521. Bitterns, dwarf, coloration of the sexes of, 461. Biziura lobata, musky odour of the male, 359 ; large size of male, 362. Blackbird, sexual differences in the, 219 ; proportion of the sexes in the, 248 ; acquisition of a song by, 370 ; colour of the beak in the sexes of the, 383, 491 ; pairing with a thrush, 414 ; colours and nidification of the, 455 ; young of the, 487 ; sexual difference in colo- ration of the, 491. Black-buck, Indian, sexual difference in the colour of the, 535. Blackcap, arrival of the male, before the female, 212; young of the, 487. Black-cock, polyg.amous, 219; pro- portion of the sexes in the, 248 ; pugnacity and love-dance of the, 363; call of the, 375 ; moulting of the, 392 ; duration of the court- ship of the, 405 ; and pheasant, hybrids of, 414 ; sexual difference in coloration of the, 491 ; crimson eye-cere of the, 491. Blacklock, Dr., on music. 572. Black-grouse, characters of young, 465, 471. Blackwall, J., on the speaking of the magpie, 90; on the desertion ot their young by swallows, 108 ; on thesuperior activity of male spiders, 221 ; on the proportion of the sexes in spiders, 254; on sexual variation of colour in spiders, 272 ; on male spiders, 272. Bladder-nose Seal, hood of the, 528. Blaine, on the affections of dogs, 523. Blair, Dr., on the relative liability of Europeans to yellow fever, 194. Blake, C. C., on the jaw from La Naulette, 40. Blakiston, Capt., on the American snipe, 377 ; on the dances of Tetrao phasianellus, 381. Blasius, Dr., on the species of Euro- pean birds, 422. Bledius taurus, hornlike processes of male, 299. Bleeding, tendency to profuse, 237. Blenkiron, Mr., on sexual preference in horses, 524. Blennies, crest developed on the head of male, during the breeding sea- son, 338. Blethisa multipunctata, stridulation of, 302. Bloch, on the proportions of the sexes in fishes, 249. Blood, arterial, red colour of, 261. pheasant, number of spurs in, 364. Bluebreast, red-throated, sexual dif- ferences of the, 472. Blumenbach, on Man, 28 ; on the large size of the nasal cavities in American aborigines, 34; on the position of man, 149 ; on the num- ber of species of man, 174. Blyth, E., on the structure of the hand in the species of Ilglobates, 61 ; observations on Indian crows, 102; on the development of the horns in the Koodoo and Eland an- telopes, 234; on the pugnacity of the males of Gallinula cristata, 360 ; on the presence of spurs in the female Euplocamm ergthrophthaltnus, 364 ; on the pugnacity of the amadavat, 366; on the spoonbill, 374 ; on the BOAR. INDEX BOURBON. moulting of Anthus, 392 ; on the moulting of bustards, plovers, and Gallus bankiva, 392 ; on the Indian honey-buzzard, 424 ; on sexual dif- ferences in the colour of the eyes of hornbills, 425 ; on Oriolus me- lanocephalus, 460 ; on Falceornis javanicus, 461; on the genus Ar- detta, 461 ; on the peregrine falcon, 461 ; on young female birds acquir- ing male characters, 461; on the immature plumage of birds, 465 ; on representative species of birds, 468 ; on the young of Turnix, 476 ; on anomalous young of Lanius rufus and Colyrribus glacialis, 482 ; on the sexes and young of the spar- rows, 483 ; on dimorphism in some herons, 484 ; on the ascertainment of the sex of nestling bullfinches by pulling out breast-feathers, 484 ; on orioles breeding in immature plumage, 484 ; on the sexes and young of Buphus and Anastomus, 486 ; on the young of the black- cap and blackbird, 487 ; on the young of the stonechat, 487 ; on the white plumage of Anastomus, 493 ; on the horns of Bovine ani- mals, 505 ; on the horns of Antilope bezoartica, 507 ; on the mode of fighting of Ovis cycloceros, 508 ; on the voice of the Gibbons, 527 ; on the crest of the male wild goat, 531 ; on the colours of Fortax picta, 535 ; on the colours of Anti- lope bezoartica, 536 ; on the colour of the Axis deer, 536 ; on sexual difference of colour in Hylobates hoolook, 537 ; on the hog-deer, 546 ; on the beard and whiskers in a monkey becoming white with age, 559. Boar, wild, polygamous in India, 217 ; use of the tusks by the, 513 ; fight- ing of, 518. Boardman, Mr., Albino birds in U. S., 419. Bcitard and Corbie, MM., on the transmis.sion of sexual peculiarities in pigeons, 230 ; on the antipathy shewn by some female pigeons to certain males, 418. Bold, Mr., on the singing of a sterile hybrid canary, 369. 60 O Bombet, on the variability of the standard of beauty in Europe, 596. Bombus, difference of the sexes in, 292. Bombycid®, coloration of, 313 ; pair- ing of the, 318 ; colours of, 318. Bombycilla carolinensis, red append- ages of, 461. Bonibyx cyntMa, 278 ; proportion of the sexes in, 250, 253 ; pairing of, 318. mori, difference of size of the male and female cocoons of, 278 ; pairing of, 318. Fernyi, proportion of sexes of, 253. Yamamai, 278 ; M. Personnaton, 251 ; proportion of sexes of, 253. Bonaparte, C. L., on the call-notes of the wild turkey, 375. Bond, F., on the finding of new mates by crows, 408. Bone, implements of, skill displayed in making, 49. Boner, C., on the transfer of male characters to an old female chamois, 504; on the habits of stags, 515 ; on the pairing of red deer, 522. Bones, increase of, in length and thickness, when carrying a greater weight, 32. Bonizzi, P., difference of colour in sexes of pigeons, 230. Bonnet monkey, 151. Bonwick, J., extinction of Tasma- nians, 183, 184. Boomerang, 145. Borens hyemalis, scarcity of the male, 254. Bory St. Vincent, on the number of species of man, 174 ; on the colours of Zabrus paw, 342. Bos etruscus, 505. gaums, horns of, 505. moschalus, 529. primigenius, 501. sondaicus, horns of, 505 ; colours of, 536. Botocudos, 144; mode of life of, 197 ; disfigurement of the ears and lower lip of the, 575. Boucher de Perthes, J. C. de, on the antiquity of man, 2. Bourbon, proportion of the sexes in a species of Favilio from, 250 634 BODRIEX. INDEX. BUOC/.. Bourien, on the marriage-customs of the savages of the Malay Archi- pelago, 598. Bovida:, dewlaps of, 531. Bower-birds, 406 ; habits of the, 381 ; ornamented playing-places of, 92, 413. Bows, use of, 179. Brachycephalic structure, possible explanation of, 56. Brachyura, 268. Brachyurus calvus, scarlet fixce of, 550. Bradley, Mr., abductor ossis metatarsi quinti in man, 42. Brain, of man, agreement of the, with that of lower animals, 6 ; convolu- tions of, in the human foetus, 1 1 ; influence of development of mental faculties upon the size of the, 54 ; influence of the development of, on the spinal column and skull, 55 ; larger in some existing mammals than in their tertiary prototypes, 81 ; relation of the development of the, to the progress of language, 87 ; disease of the, affecting speech, 88 ; difference in the convolutions of, in different races of men, 167 ; supplement on, by Prof. Huxley, 1 99 ; development of the gyri and sulci, 204. Brakenridge, Dr., on the influence of climate, 32. Brandt, A., on hairy men, 19. Braubach, Prof., on the quasi-religious feeling of a dog towards his master, 96 ; on the self-restraint of dogs, 103. Brauer, F., on dimorphism in Weuro- thcmis, 291. Brazil, skulls found in caves of, 168 ; population of, 173 ; compression of the nose by the natives of, 583. Break between man and the apes, 156. Bream, proportion of the sexes in the, 249. Breeding, age of, in birds, 484. • season, sexual characters making their appearance in the, in birds, 390. Brehm, on the effects of intoxicating liquors on monkeys, 7 ; on the recognition of women by male Cyno^ cephali, 8 ; on the divei-sity of the mental faculties of monkeys, 27 ; on the habits of baboons, 51 •, ou revenge taken by monkeys, 69; on manifestations of maternal affection by monkeys and baboons, 70 ; on the instinctive dre-ad of monkeys for serpents, 71 ; on the use of stones as missiles by baboons, 81 : on a baboon using a mat for shelter from the sun, 82 ; on the signal- cries of monkeys, 87 ; on sentinels posted by monkeys, 101 ; on co-ope- ration of animals, 101 ; on an eagle attacking a young Cercopithecus, 101 ; on baboons in confinement pro- tecting one of their number from punishment, 103 ; on the habits of baboons when plundering, 104; on polygamy in Cynocephalus and Cebus, 217 ; on the numerical pro- portion of the sexes in birds, 247 ; on the lox'e-dance of the black-cock, 363 ; on Palamedea cornuta, 366 ; on the habits of the Black-grouse, 366 ; on sounds produced by birds of paradise, 376 ; on assemblages of grouse, 405 ; on the finding of new mates by birds, 409 ; on the fight- ing of wild boars, 518 ; on the- habits of Cynocephalus hamadryas, 590. Brent, Mr., on the courtship of fowls. 417. Breslau, numerical proportion of male and female births in, 243. Bridgman, Laura, 88. Brimstone butterfly, 312 ; sexual dif- ference of colour in the, 322. British, ancient, tattooing practised by, 574, Broca, Prof., on the occurrence of the supra-condyloid foramen in the human humerus, 22 ; anthropo- morphous apes more bipedal than quadrupedal, 53; on the c.apacityof Parisian skulls at different periods, 55 ; comparison of modern and mediaxv.al skulls, 55 ; on tiiils of quadrupeds, 58 ; on the influence of natural selection, 61 ; on hybridity in man, 170 ; on human remtiins from Lcs Eyzies, 181 ; on the cause of the difference between Eurojxeans- and Hindoos, 192. BRODIE. INDEX. BURCHELL. 635 Brodie, Sir B., on the origin of the moral sense in man, 98. Bronn, H. G., on the copulation of insects of distinct species, 275. Bronze period, men of, in Europe, 128. Brown, R., sentinels of seals generally females, 100 ; on the battles of seals, 500 ; on the narwhal, 502 ; on the occasional absence of the tusks in the female walrus, 502 ; on the bladder-nose seal, 528 ; on the colours of the seres in Fhoca Grxnlandica, 535 ; on the appre. ciation of music by seals, 569 ; on plants used as love-philters, by North American women, 577. Brown, Dr. Crichton, injury to infants during parturition, 244. Brown-Sequard, Dr., on the inheri- tance of the effects of operations by guinea-pigs, 60, 603. Bruce, on the use of the elephant’s tusks, 507. Brulerie, P. de la, on the habits of Ateuchus cicatricosus, 300 : on the stridulation of Ateuchus, 306. Briinnich, on the pied ravens of the Feroe islands, 424. Bryant, Dr., preference of tame pigeon for wild mate, 418. , Capt, on the courtship of Callorhinus ursinus, 522, Bubas bison, thoracic projection of, 298. Bucephalus aapensis, difference of the seres of, in colour, 351. Buceros, nidification and incubation of, 454. ■ bicomis, serual differences in the colouring of the casque, beak, and mouth in, 425, — corrugatus, sexual differences in the beak of, 383. Biichner, L., on the origin of man, 3 ; on the use of the human foot as a pi-ehensile organ, 52 ; on the mode of progression of the apes, 52 ; on want of self-consciousness, &c,, in savages, 83. Bucholz., Dr., quarrels of chama:leons, 357. Buckland, F., on the numerical pro- portion of the seres in rats, 247 ; on the proportion of the sexes in the trout, 249 ; on Chimcera man- strosa, 338. Buckland, W., on the complexity of crinoids, 91. Buckler, W., proportion of sexes of Lepidoptera reared by, 253. Buckinghamshire, numerical propor- tion of male and female births in, 242. Bucorax abyssinicus, inflation of the neck-wattle of the male during courtship, 383. Budytes Bail, 212. Buffijlo, Cape, 508. , Indian, horns of the, 505. , Italian, mode of fighting of the, 508. Buffon, on the number of species of man, 174. Bufo sikimmensis, 349. Bup, 281. Buist, R., on the proportion of the sexes in salmon, 249 ; on the pug- nacity cf the male salmon, 332. Bulbul, pugnacity of the male, 360 ; display of under tail-coverts by the male, 402. Bull, mode of fighting of the, 508 ; curled frontal hair of the, 531. Buller, Di\, on the Huia, 208 ; the attachment of birds, 410. Bullfinch, sexual differences in the, 219 ; piping, 369 ; female, singing of the, 370 ; courtship of the, 401 ; widowed, finding a new mate, 408 ; attacking a reed-bunting, 412; nestling, sex ascertained by pulling out breast-feathers, 484, Bullfinches distinguishing persons, 412 ; rivalry of female, 420. Bulls, two young, attacking an old one, 101 ; wild, battles of, 501. Bull-trout, male, colouring of, during the breeding season, 340. Bunting, reed, head feathers of the male, 402 ; attacked by a bullfinch, 412. Buntings, characters of young, 464. Buphus coromandus, sexes and young of, 486 ; change of colour in, 494, 495. Burchell, Dr., on the zebra, 545 ; on the extravagance of a bushwoman in adorning herself, 577 ; celibaov unknown among the savages o'f bouth Africa, 594 ; on the mar- 636 BURKE. INDEX. CANINE. riage-customs of the Bushwomen, 598. Burke, on the number of species of man, 174. Burmese, colour of the beard in, 558. Burton, Capt., on negro ideas of female beauty, 579 ; on a universal ideal of beauty, 582. Bushmen, 64. Bushvsroman, extravagant ornamenta- tion of a, 577. Bushwomen, hair of, 167 ; marriage- ousioms or, ot?cs. Busrara, tnroat-pouch of the male, 373 ; humming noise produced by a male, 377 ; Indian, ear-tufts of, 384. Bustards, occurrence of sexual dif- ferences and of polygamy among the, 219 ; love-gestures of the male, 380 ; double moult in, 390, 392. Butler, A. G., on sexual differences in the wings of Aricoris epitus, 277 ; courtship of butterflies, 307 ; on the colouring of the sexes in species of Theola, 310 ; on the re- semblance of Ip/lias glaucippe to a leaf, 313 ; on the rejection of cer- tain moths and caterpillar’s by lizards and frogs, 326. Butterfly, noise produced by a, 307 ; Emperor, 307, 308 ; meadow brown, instability of the ocellated spots of, 428. Butterflies, proportion of the sexes in, 250 ; forelegs atrophied in some male, 277 ; sexual difference in the neuration of the wings of, 277 ; pugnacity of male, 307 ; protective resemblances of the lower surface of, 311 ; display of the wings by, 314; white, alighting upon bits of paper, 317 ; attracted by a dead specimen of the same species, 317 ; courtship of, 317 ; male and female, inhabiting different stations, 321. Buxton, C., observations on macaws, 102 ; on an instance of benevolence in a parrot, 411. Buzzard, Indian honey-, variation in the crest of, 424. C. Cabbage butterflies, 312. Cachalot, large head of the male, 502. Cadences, musical, perception of, by animals, 569. Caicum, 20 ; large, in the early pro- genitors of man, 160. Cairina moschata, pugnacity of the male, 362. Californian Indians, decrease of, 258. Callianassa, chelae of, figured, 267, Callidryas, colours of sexes, 318. Callionymus lyra, characters of the male, 33.5. Callorhinus ursinu-s, relative size of the sexes of, 515 ; courtship of, 522. Cedotes maria, 358. nigrilabris, sexual difference in the colour of, 357. Cambridge, 0. Pickard, on the sexc.’i of spiders, 255 ; on the size of male Nephila, 273. Camel, canine teeth of male, 502, 514. Campbell, J., on the Indian elephant. 218 ; on the proportion of male and female births in the harems of Siam, 245. Campyloptenis hemileitcunts, 248. Canaries distinguishing persons, 412 Canary, polygamy of the, 220 ; change of plumage in, after moulting, 238 , female, selecting the best singing male, 268 ; sterile hybrid, singing of a, 369 ; female, singing of the, 370; selecting a greenfinch, 415; and siskin, pairing of, 415. Canestrini, G., on rudimentai’y cha- racters and the origin of man, 3 ; on rudimentary characters, 11; on the movement of the ear in man, 14; on the variability of the ver- miform appendage in man, 21; on the abnormal division of the malar bone in man, 39 ; on abnormal con- ditions of the human uterus, 39 ; on the persistence of the frontal suture in man, 39 ; on the propor- tion of the sexes in silk-moths, 250, 251 ; secondary sexual characters of spiders, 272. Cancer pagurus, 266. Canfield, Dr., on the horns of the Antilocapra 234. Canine teeth in man, 46 ; diminution of, in man, 53; diminution of, in horses, 53 ; disappearance of, in CANINES. INDEX. CEBUS. 637 male ruminants, 53 ; large, in the early progenitors of man, 160. Canines, and horns, inverse develop- ment of, 514. Canoes, use of, 48, 180. Canthans, difference of colonr in the sexes of a species of, 294. Cantharus lineatus, 341. C.apercailzie, polygamous, 219 ; pro- portion of the sexes in the, 248 ; pugnacity of the male, 363 ; pairing of the, 367 ; autumn meetings of the, 370; call of the, 375; dura- tion of the courtship of, 405 ; beha- viour of the female, 419; inconve- nience of black colour to the female, 444 ; sexual difference in the colora- tion of the, 491 ; crimson eye-cere of the male, 491. Capitonidie, colours and nidification of the, 455. Capra wgagrus, 508 ; crest of the male, 531 ; sexual difference in the colour of, 536. Capreolus Sibirious subecaudatus, 542. Caprice, common to man and animals, 93. Caprimulgus, noise made by the males of some species of, with their wings, 376. virginianus, pairing of, 366. Garabidse, 302. C.arbonnier, on the natural hi.story of the pike, 249 ; on the relative size of the .sexes in fishes, 335 ; court- ship of Chinese Macropus, 341. Carcineutes, sexual difference of colour in, 457. Carcinus manas, 268, 269. Cardinalis virginianus, 225. Carduelis elegans, sexual differences of the beak in, 360. Carnivora, marine, polygamous habits of, 218 ; sexual differences in the colours of, 534. Carp, numerical proportion of the sexes in the, 249. Carr, K., on the peewit, 366. Carrier pigeon, late development of the wattle in the, 238. Carrion beetles, stridulation of, 302. Cams, Prof. V., on the development of the horns in merino sheep, 235. Cassowary, sexes and incubation of the, 478. Castina, mode of holding wings, 315. Castoreum, 529. Casuarius galeatus, 478. Cat, convoluted body in the extremity of the tail of a, 23 ; sick, sympathy of a dog with a, 103. Cataract in Cebus Azarw, 7. Catarrh, liability of Cebus Azarce to, 7. Catarrhine monkeys, 153. Caterpillars, bright colours of, 325. Cathartes aura, 416. jota, love-gestures of the male, 380. Gatlin, G., correlation of colour and texture of hair in the Mandans, 197; on the development of the beard among North American Indians, 560 ; on the gi-eat length of the hair in some North American tribes, 580. Caton, J. D., on the development of the horns in Cervus virginianus and strongyloceros, 234 ; on the presence of traces of horns in the female wapiti, 504; on the fighting of deei-, 510 ; on the crest of the male wapiti, 531 ; on the coloui-s of the Virginian deei-, 535 ; on sexual dif- ferences of colonr in the wapiti, 536 ; on the spots of the Virginian deer, 546. Cats, dreaming, 74 ; tortoise-shell, 230, 232, 237 ; enticed by valerian, 530 ; colours of, 543, Cattle, rapid increase of, in South America, 47 ; domestic, lighter iu winter in Siberia, 229 ; horns of, 234 505 ; domestic, sexual differences of. late developed, 238 ; numerical pro- portion of the sexes in, 246. Caudal vertebrse, number of, in ma- caques and baboons, 58 ; basal, of monkeys, imbedded in the body, 59. Cavolini, observations on Serranus, 162. Cebus, maternal affection in a, 70.; gradation of species of, 175. Apella, 205. Azarce, liability of, to the same diseases as man, 7 ; distinct sounds produced by, 84 ; early maturity of the female, 558. capucinus, polygamous, 217 ; sexual differences of colour in, 537 ; hair on the head of, 549. 638 CEBUS. INDEX. CHELOXIA. Cebus veltorosus, hair on the head of, 549. Cecidomyidae, proportions of the sexes in, 354. Celibacy, unknown among the savages of South Africa and South America, 594. Centipedes, 274. Cephalopoda, absence of secondary sexual characters in, 263. Cephaloptcrus ornatus, 373. penduUger, 374. Cerambyx heros, stridulant organ of, 303. Ceratodus, paddle of, 37. Ceratophora aspera, nasal appendages of, 355. Stoddartii, nasal horn of, 355. Ccrceris, habits of, 291. Cereocebus athiops, whiskers, &c., of, 550. Cercopithecus, young, seized by an eagle and rescued by the troop, 101; definition of species of, 175. • cephus, sexual diflerence of colour in, 537, 552. cynosurus and griseoviridis, colour of the scrotum in, 537. • Diana, sexual differences of colour in, 537, 552, 553. griseo-viridis, 101. petaurista, whiskers, &c., of, 550. Ceres, of birds, bright colours of, 491. Ceriornis Temminc/cii, swelling of the wattles of the male during court- ship, 383. Corvulits, weapons of, 514. moschatus, rudimentary horns of the female, 504. Cervus alces, 234. campestris, odour of, 529. canadensis, traces of horns in the female, 504 ; attacking a man, 511 ; sexual difference in the colour of, 536. elaphus, battles of male, 501 ; horns of, with numerous points, 510. Eldi, 234. mantchuriens, 546. paludosus, colours of, 536. strongyloceros, 234. virginianua, 234 ; horns of, in course of modification, 511. Ceryle, male black-belted in some species of, 457. Cetacea, nakedness of, 56. Ceylon, frequent absence of beard in the natives of, 560. Cliaifinch, proportion of the sexes in the, 248 ; courtship of the, 401. Chaffinches, 369 ; new mates found by, 408. Chalcophaps indiciis, characters of young, 465, Chalcosoma atlas, sexual difierences of, 295. Chamxko, sexual differences in the genus, 356. bifurcus, 356, 357. Owenii, 357. pumilus, 357. Chamcepetes •vnicohr, modified wing- feather in the male, 377. Chameleons, 354. Chamois, danger-signals of, 100; transfer of male characters to an old female, 504. Champneys, Mr., acromio-basilar muscle and quadrupedal gait, 42. Chapuis, Dr., on the transmission of sexual peculiarities in pigeons, 230; on streaked Belgian pigeons, 238, 446. Char, male, colouring of, during the breeding season, 340. Characters, male, developed in fe- males, 227 ; secondary sexual, transmitted through both sexes, 227 ; natural, artificial, exaggera- tion of, by man, 582. Charadrius hiaticula and pluvialis, sexes and young of, 485. Chardin on the Persians, 586. Charms, worn by women, 577. Charruas, freedom of divorce among the, 598. Chasmorhynchus, difference of colour in the se.xes of, 389 ; colours of, 492. niveus, 389. tricartmculatiis, 389. Chastity, early estimation of, 119. Chatterers, sexual differences in, 219. Cheever, Rev. H. T., census of the Sandwich Islands, 257. Cheiroptera, absence of secondary sexual characters in, 218. Chela: of Crustacea, 266, 271. Chelonia, sexual differences in 350. CHENALOPEX. INDEX. COCHIN-CHINA. 639 ■Chenalopex cngyptiacus, wing-knobs of, 364. Chera progne, 392, 419. Cliest, proportions of, in soldiers and sailors, 32 ; large, of the Quechua and Aymara Indians, 34. ■Chevrotains, canine teeth of, 514. Chiasognathus, stridulation of, 306. Grantii, mandibles of, 300. Children, legitimate and illegitimate, proportion of the sexes in, 243. Chiloe lice of the natives of, 170 ; population of, 173. Chiincera monstrosa, bony process on the head of the male, 338. Chimseroid fishes, prehensile organs of male, 331. ■Chimpanzee, 561; ears of the, 14; representatives of the eyebrows in the, 19 ; hands of the, 50 ; absence of mastoid processes in the, 53 ; platforms built by the, 66 ; crack- ing nuts with a stone, 81 ; direc- tion of the hair on the arms of the, 151 ; supposed evolution of the, 177 ; polygamous and social habits of the, 590. China, North, idea of female beauty in, 578. , Southern, inhabitants of, 197 Chinese, use of flint tools by the, 145 ; difficulty of distinguishing the races of the, 167 ; colour of the heard in, 558 ; general beardless- ness of the, 560 ; opinions of the, on the appearance of Europeans and Cingalese, 578: compression of the feet of, 583. Chin.surdi, his opinion of beards, 576, 581. Ghlamydera maculata, 382. ■Chloeon, pedunculated eyes of the male of, 274. Chloephaga, coloration of the sexes in, 460. Chlorocoelus Tanana (figured), 285. Chorda Dorsalis, 161. Chough, red beak of the, 491. Chromida:, frontal protuberance in male, 340 ; sexual differences in colour of, 345. Chrysemys picta, long claws of the male, 350. Chrysococcyx, characters of younc of, 465. ^ Chrysomelida:, stridulation of, 302. Cicada pruinosa^ 282. • septendecim, 282. CicadsB, songs of the, 281 ; rudimen- tary sound-organs in females of, 288. Cicatrix of a burn, causing modifica- tion of the facial bones, 55. , Cichla, frontal protuberance of male. 340. Cimetibre du Sud, Paris, 22. Cincloramphus cruralis, large size of male, 362. Cinclus aqiiaticus, 455. Cingalese, Chinese opinion of the ap- pearance of the, 578. Cirripedes, complemental males of, 208. Civilisation, effects of, upon natural selection, 133 ; influence of, in the competition of nations, 183. Clanging of geese, &c., 368. Claparbde, E., on natural selection applied to man, 49. Clarke, on the marriage-customs of the Kalmucks, 598. Classification, 148. Claus, C., on the sexes of Saphirina, 271. Cleft-palate, inherited, 35. Climacteris erythrops, sexes of, 479. Climate, 31 ; cool, favourable to hu- man progress, 133 ; power of sup- porting extremes of, by man, 182 ; want of connexion of, with colour, 192. Cloaca, existence of a, in the early progenitors of man, 161. Cloacal passage existing in the hu- man embryo, 9. Clubs, used as weapons before disper- sion of mankind, 180. Clucking of fowls, 368. Clythra i-punctata, stridulation of, 302. Coan, Mr., Sandwich-islanders, 187. Cobbe, Miss, on morality in hypothe- tical bee-community, 99. Cobra, ingenuity of a, 352. Coccus, 147. Coccyx, 22, 23 ; in the human em- bryo, 9 ; convoluted body at the extremity of the, 23 ; imbedded in the body, 59. Cochin-China, notions of beauty of the inhabitants of, 578, 580. 640 COCK. INDEX. COSMETOUNIS. Cock, blind, fed by its companions, 103 ; game, killing a kite, 363 ; comb and wattles of the, 403 ; pre- ference shewn by the, for young hens, 420 ; game, transparent zone in the hackles of a, 430. Cock of the rock, 405. Cockatoos, 491, 492, 493 ; nestling, 411 ; black, immature plumage of, 467. Coelenterata, absence of secondary sexual characters in, 260. Coflfee, fondness of monkeys for, 7. Cold, supposed effects of, 32 ; power of supporting, by man, 182. Coleoptera, 294 ; stridulation of, 284 ; stridulant organs of, discussed, 303. Colias edusa and hyale, 319. Collingwood, C., on the pugnacity of the buttei-flies of Borneo, 307 ; on butterflies being attracted by a dead specimen of the same species, 317. Colobus, absence of the thumb, 51. Colombia, flattened heads of savages of, 575. Colonists, success of the English as, 142. Coloration, protective, in birds, 489. Colour, supposed to be dependent on light and heat, 32 ; correlation of, with immunity from certain poisons and parasites, 193 ; purpose of, in lepidoptera, 316 ; relation of, to sexual functions, in fishes, 343 ; difference of, in the sexes of snakes, 351 ; sexual differences of, in lizards, 357 ; influence of, in the pairing of birds of different species, 415 ; relation .of, to uidification, 453, 456 ; sexual differences of, in mammals, 533, 540 ; recognition of, by quadrupeds, 540 ; of children, in different races of man, 557 ; of the skin in man, 604. Colours, admired alike by man and animals, 93 ; bright, due to sexual selection, 261 ; bright, among the lower animals, 261, 262; bright, protective to butterflies and moths, 313; bright, in male fishes, 335, 340 ; transmis.sion of, in birds, 448. Colquhonn, example of reasoning in a retriever, 78. Columba p'lsserina, young of, 467. Colywbus glacialis, anomalous young of, 482. Comb, development of, in fowis, 239. Combs and wattles in male birds, 403. Community, preservation of variations useful to the, by natural selection, 62. Composita:, gradation of species among the, 175. Comte, C., on the expression of the ideal of beauty by sculpture, 581. Conditions of life, action of changed, upon man, 30 ; influence of, on plumage of birds, 472. Condor, eyes and comb of the, 472. Conjugations, origin of, 91. Conscience, 114, 126; absence of, in some criminals, 116. Constitution, difference of, in different races of men, 168. Consumption, liability of Cehns Azarce to, 7 ; connexion between com- plexion and, 194. Convergence of characters, 177. Cooing of pigeons and doves, 374. Cook, Capt., on the nobles of the Sandwich Islands, 586. Cope, E. D., on the Dinosauria, 158. Cophotis ceylanica, sexual difl'erences of, 354, 357. Copris, 295. Isidis, sexual differences of, 296. ' lunaris, stridulation of, 303. Corals, bright colours of, 260. Coral-snakes, 353. Cordylus, sexual difference of colour ■ in a species of. 357. Corfu, habits of the Chaffinch in, 248. Cornelius, on the proportions of the sexes in Lucanus Cervus, 253. Corpora Wolffiana, 161 ; agreement of, with the kidneys of fishes, 11. Correlated variation, 43. Correlation, influence of, in the pro- duction of races, 197. Corse, on the mode of fighting of the elephant, 514. Corvus corone, 408. graculits, red beak of, 491. pica, nuptial assembly of, 406. Corydalis comutus, large jaws of the male, 275. Cosmetomis, 462. COSMETORNIS. INDEX. CYANECULA. 641 Cosmetomis vexillarius, elongation of wing-feathers in, 384, 403. CotingidsB, sexual differences in, 219 ; coloration of the sexes of, 460 ; re- semblance of the females of distinct species of, 470. Cottus scorpius, sexual differences in, 337. Coulter, Dr., on the Californian In- dians, 258. Counting, origin of, 144 ; limited power of, in primeval man, 180. Courage, variability of, in the same species, 69 ; universal high appre- ciation of, 118 ; importance of, 130 ; characteristic of men, 564. Courtship, greater eagerness of males in, 221 ; of fishes, 331, 341 ; of birds, 367, 405. Cow, winter change of colour, 542. Crab, devil, 269. , shore, habits of, 268. C'rabro cribrarius, dilated tibiae of the male, 276. Crabs, proportions of the sexes in, 255. Cranz, on the inheritance of dexterity in seal catching, 33. Crawfurd, on the number of species of man, 174. Crenilabrus massa and C. melops, nests built by, 345. Crest, origin of, in Polish fowls, 231. Crests, of birds, difference of, in the sexes, 467 ; dorsal hairy, of mam- mals, 530. Cricket, field-, stridulation of the, 283 ; pugnacity of male, 289. , house-, stridulation of the 283, 284. Crickets, sexual differences in, 289. Crioceridae, stridulation of the, 302. Crinoids, complexity of, 91. Croaking of frogs, 350. Crocodiles, musky odour of, during the breeding season, 351. Crocodilia, 351. Crossbills, characters of young, 464. Crosses in man, 173. Crossing of races, effects of the, 192. Crossoptilon auritum, 400, 452, 472 • adornment of both sexes of, 235 • sexes alike in, 460. Crotch, G. R., on the stridulation of beetles, 302, 304; on the stridu- j lation of Heliopathes, 305; on the stridulation of Acalles, 306 ; habit of female deer at breeding time, 503. Crow Indians, long hair of the, 580. , young of the, 481. Crows, 491 ; vocal organs of the, 370 ; living in triplets, 409. — carrion, new mates found by, 407. , Indian, feeding their blind com- panions, 103. Cruelty of savages to animals, 118. Crustacea, parasitic, loss of limbs by female, 208 ; prehensile feet and antenme of, 209 ; male, more active than female, 221 ; parthenogenesis in, 255 ; secondary sexual charac- ters of, 265 ; amphipod, males sexually mature while young, 485 ; auditory hairs of, 568. Crystal worn in the lower lip by some Central African women, 575. Cuckoo fowls, 238. Culicidae, 208, 280 ; attracted by each other’s humming, 280. Cullen, Dr., on the throat-pouch of the male bustard, 373. Cultivation of plants, probable origin of, 133. Cupples, Mr., on the numerical pro- portion of the sexes in dogs, sheep, and cattle, 246 ; on the Scotch deerhound, 516 ; on sexual pre- ference in dogs, 524. Curculionida;, sexual difference in length of snout in some, 208 ; hornlike processes in male, 299 ; musical, 301, 302. Curiosity, manifestations of, by ani- mals, 71. Curlews, double moult in, 390. Cursores, comparative absence of sexual differences among the-, 219. Curtis, J., on the proportion of the sexes in Athalia, 254. Cuvier, F., on the recognition of women by male quadrumana, 8. , G., on the number of caudal vertebrie in the mandrill, 58 ; on instinct and intelligence, 67 ; views of, as to the position of man, 149 ; on the position of the seals, 150; on Hectocotyle, 263. Cyanecula auecica, sexual differences of, 472. 2 T 642 CrANALCYON. INDEX. DENDaOPHlLA. Cyanalcym, sexual difiference in colours of, 457 ; immature plu- mage of, 467. Cychrus, sounds produced by, 304. Cycnia mendica, sexual difference of, in colour, 316. Cygnus fertis, trachea of, 374. olor, white young of, 482. Cyllo Leda, instability of the ocellated spots of, 428. Cynanthus, variation in the genus, 423. CynipidsE, proportions of the sexes in, 254. Cynoccphalus, difference of the young from the adult, 8 ; male, recogni- tion of women by, 8 ; polygamous habits of species of, 217. chacma. 70. gelada, 81. ■ /latnadryas, 81, 590 ; sexual dif- ference of colour in, 537. leucophus, colours of the sexes of, 538. mormon, colours of the male, 538, 540, 550. porcarius, mane of the male, 521. Cypridina, proportions of the sexes in, 255. Cyprinida:, proportion of the sexes in the, 249. , Indian, 343. Cyprinodontidse, sexual differences in the, 335, 337. Cyprinus auratus, 342. Cypris, relations of the sexes in, 255. Cyrtodactylus rubidus, 354. Cystophora cristata, hood of, 528. D. Bacelo, sexual difference of colour in, 457. Gaudichaudi, young male of, 467. Dal-ripa, a kind of ptarmigan, 248. Bamalis albifrons, peculiar markings of, 544. pyg<^’’g<’^j peculiar markings of, 543. Dampness of climate, supposed influ- ence of, on the colour of the skin, 32, 193. Danaidre, 308. Dances of birds, 380. Dancing, universality of, 178. Daniell, Dr., his experience of resi- dence in West Africa, 195. Darfur, protuberances artificially pro- duced by natives of, 574. Darwin, K., on the stridulation of Dermestes murinus, 302. Dasychira pvdibunda, sexual difference of colour in, 316. Davis, A. H., on the pugnacity of the male stag-beetle, 300. , J. B., on the capacity of the skull in various races of men, 54 ; on the beards of the Polynesians, 560. Death-rate higher in towns than in rural districts, 139. Death-tick, 306. De Candolle, Alph., on a case of in- herited power of moving the scalp, 13. Declensions, origin of, 91. Decoration in birds, 381. Decticus, 285. Deer, 233 ; development of the horns in, 233 ; spots of young, 464, 546 ; horns of, 503, 506 ; use of horns of, 510, 518 ; horns of a, in course of modification, 511; size of the horns of, 515 ; female, pairing with one male, whilst others are fighting for her, 522 ; male, attracted by the voice of the female, 527 ; male, odour emitted by, 529. , Axis, sexual difference in the colour of the, 537. , fallow, different coloured herds of, 540. , Mantchurian, 546. • , Virginian, 546 ; colour of the, not affected by castration, 535; colours of, 536. Deerhound, Scotch, greater size of the male, 237, 516. Defensive organs of mammals, 518. De Geer, C., on a female spider de- stroying a male, 273. Dekay, Dr., on the bladder-nose seal, 528. Delorenzi, G., division of malar bone, 39. Demerara, yellow fever in, 194. JDendrocygna, 465. Dendrophila frontalis, young of, 487. DENISON. INDEX. DOGS. 643 Denison, Sir W., manner of ridding themselves of vermin among the Australians, 57 ; extinction of Tas- manians, 184. Denny, H., on the lice of domestic animals, 169. Dermestes murimts, stridulation of, 302. Descent traced through the mother alone, 588. Deserts, protective colouring of ani- mals inhabiting, 489. Desmarest, on the absence of sub- orbital pits in Antilope subguttu- rosa, 529 ; on the whiskers of Macacus, 531 ; on the colour of the opossum, 534 ; on the colours of the se.ves of Mus minutus, 534 ; on the colouring of the ocelot, 534 ; on the colours of seals, 535 ; on Antilope caama, 536 ; on the colours of goats, 536 ; on sexual difference of colour in Aides mar- ginatus, 537 ; on the mandrill, 539 ; on Macacus cynomolgus, 558. Desmoulins, on the number of species of man, 174 ; on the musk-deer, 530. Desor, on the imitation of man by monkeys, 72. Despine, P., on criminals destitute of conscience, 116. Development, embryonic, of man, 9, 11 ; correlated, 426. Devil, not believed in by the Fue- gians, 95. Devil-crab, 269. Devonian, fossil insect from the, 289. Dewlaps, of cattle and antelopes, 531. Diadema, sexual differences of colour- ing in the species of, 309. Diamond-beetles, bright colours of, 294. Diastema, occurrence of, in man, 35. Diastylidse, proportion of the sexes in, 255. Dicrurus, racket-shaped feathers in, 384 ; nidification of, 453. macrocercus, change of plumage in, 461. Didelphis opossum, sexual difference in the colour of, 533. Differences, comparative, between dif- ferent species of birds of the same sex, 470. Digits, supernumerary, more frequent in men than in women, 223 ; super- numerary, inheritance of, 232 ; supernumerary, early development of, 237. Dimorphism in females of water- beetles, 276 ; in Neurothemis and Agrion, 291. Diodorus, on the absence of beard in the natives of Ceylon, 560. Dipelicus Cantori, sexual differences of, 296. Diplopoda, prehensile limbs of the male, 274. Dipsas cynodon, sexual difference in the colour of, 351. Diptera, 280. Disease, generated by the contact of distinct peoples, 183. Diseases common to man and the lower animals, 7 ; difference of liability to, in different races of men, 167 ; new, effects of, upon savages, 182 ; sexually limited, 237. Display, coloration of Lepidoptera for, 314 ; of plumage by male birds, 394, 402. Distribution, wide, of man, 48 ; geo- graphical, as evidence of specific distinctness in man, 169. Disuse, effects of, in producing rudi- mentary organs, 12; and use of parts, effects of, 32 ; of parts, in- fluence of, on the races of men, 197. Divorce, freedom of, among the Char- ruas, 598. Dixon, E. S., on the pairing of different species of geese, 415 ; on the court ■ ship of peafowl, 419. Dobrizhoffer, on the marriage-customs of the Abipones, 599. Dobson, Dr., on the Cheiroptera, 218 ; scent-glands of bats, 529 ; fru- givorous bats, 534. Dogs, suffering from Tertian ague, 8 ; memory of, 74; dreaming, 74; diverging when drawing sledges over thin ice, 75; exercise of reason- ing faculties by, 78 ; domestic, pro- gress of, in moral qualities, 80; distinct tones uttered by, 84 ; parallelism between his affection for his master and religious feeling, 96 ; sociability of the, 100; sympathy of, 2 T 2 DOLICHOCEPHALIC. INDEX. EAGLE. with a sick cat, 103 ; sympathy of, with his master, 103 ; their posses- sion of conscience, 103 ; possible use of the hair on the fore-legs of the, 151; races of the, 176; numerical proportion of male andfemalebirths in, 246; sexual affection between in- dividuals of, 524; howling at certain notes, 569 ; rolling in carrion, 530. Dolichocephalic structure, possible cause of, 56. Dolphins, nakedness of, 56. Domestic animals, races of, 176; change of breeds of, 596. Domestication, influence of, in re- moving the sterility of hybrids, 172 D’Orbigny, A., on the influence of dampness and dryness on the colour of the skin, 193 ; on the Yuracaras, 582. Dotterel, 477. Doubleday, E., on sexual differences in the wings of butterflies, 277. , H. on the proportion of the sexes in the smaller moths, 251 ; males of Lasiocampa quercus and on the attraction of the Sa- turnia carpini by the female 252 ; on the proportion of the sexes in the Lepidoptera, 252 ; on the tick- ing of Anobium tesselatum, 306 ; on the structure of Ageronia foronia, 307 ; on white buttei'flies alighting upon paper, 317. Douglas, J. W., on the sexual differ- ences of the Hemiptera, 281 ; on the colours of British Homoptera, 282. Down, of birds, 390. Draco, gular appendages of, 355. Dragonet, Gemmeons, 336. Dragon-flies, caudal appendages of male, 276 ; relative size of the sexes of, 279 ; difference in the sexes of, 290 ; want of pugnacity by the male, 291. Drake, breeding plumage of the, 393. Dreams, 74; a possible source of the belief in spiritual agencies, 94. Drill, sexual difference of colour in the, 538. Dromwus, irroratua, 478. Dromolaia, Saharan species of, 456. Drongo shrike, 461. Drongos, racket-shaped feathers in the tails of, 384, 392. Dryness, of climate, supposed influence of, on the colour of the skin, 193. Dryopithecus, 155. Duck, harlequin, age of mature plu- mage in the, 483 : breeding in im- mature plumage 484. , long-tailed, preference of male, for certain females, 420. , pintail, pairing with a wigeon, 414. , voice of the, 374 ; pairing with a shield-drake, 414 ; immature plumage of the, 466. • , wild, sexual differences in the 219 ; speculum and male charac- ters of, 236 ; pairing with a pintail drake, 415. Ducks, wild, becoming polygamous under partial domestication, 219 ; dogs and cats recognised by, 412. Dufosse, Dr., sounds produced by fish, 347. Dugong, nakedness of, 56 ; tusks of, 502. Dujardin, on the relative size of the cerebral ganglia In insects, 54. Duncan, Dr., on the fertility of early marriages, 138 ; comparative health of married and single, 140. Dupont, M., on the occurrence of the supra-condyloid foramen in the humerus of man, 22. Durand, J. P., on causes of variation, 30. Dureau de la Malle, bn the songs of birds, 86 ; on the acquisition of an air by blackbirds, 370. Dutch, retention of their colour by the, in South Africa, 193. Duty, sense of, 97. Duvaucel, female Ilylobates washing her young, 70. Dyaks, pride of, in mere homicide, 117. Dynastes, large size of males of, 279. Dynastini, stridulation of, 303. Dytiscus, dimorphism of females of, 276 ; grooved elytra of the female, 276. E. Eagle, young Cercopithecus rescued from, by the troop, 101. , white-headed, breeding in im- mature plumage, 484. EAGLES INDEX. ENGLEHEAKT. 645 Eagles, golden, new mates found by, 408. Ear, motion of the, 13 ; external shell of the, useless in man, 14; rudimentary point of the, in man, 15. Ears, more variable in men than women, 224; piercing and orna- mentation of the, 575. Earwigs, parental feeling in, 106. Echidna, 156. Echini, bright colours of some, 260. Echinodermata, absence of secondary sexual characters in, 260. Echis carinata, 353. Ecker, figure of the human embryo, 10 ; on the development of the gyri and sulci of the brain, 204 ; on the sexual differences in the pelvis in man, 557 ; on the pre- sence of a sagittal crest in Austra- lians, 558. Edentata, former wide range of, in America, 169; absence of secondary sexual characters in, 218. Edolius, racket-shaped feathers in, 384. Edwards. Mr., on the proportion of the sexes in North American species oiFapilio, 250. Eels, hermaphroditism of, 162. Egerton, Sir P., on the use of the antlers of deer, 510 ; on the pairing of red deer, 522 ; on the bellowing of stags, 526. Eggs, hatched by male fishes, 345. Egret, Indian, sexes and young of, 486. Egrets, breeding plumage of, 391 ; white, 492. Ehrenberg, on the mane of the male Hamadryas baboon, 521. Ekstrom, M., on Harelda glacialis, 420. Elachista rufocinerea, habits of male, 252. Eland, development of the horns of the, 234. Elands, sexual differences of colour in 535 Elaphomyia, sexual differences in, 280. Elaphrus iiliginosue, stridulation of, 302. Elaps, 353. Elaterida;, proportions of the sexes in, 253. Elaters, luminous, 278. Elephant, 156; rate of increase of the, 47 ; nakedness of the, 57 ; In- dian, forbearance to his keeper, 104; polygamous habits of the, 218 ; pugnacity of the male, 501 ; tusks of, 502, 503, 507, 515 ; Indian, mode of fighting of the, 513 ; male, odour emitted by the, 529; attacking white or grey horses, 540. Elevation of abode, modifying in- fl^uence of, 35. Elimination of inferior individuals, 137. Elk, 507; winter change of the, 542. , Irish, horns of the, 515. Ellice Islands, beards of the natives, 560, 581. Elliot, E., on the numerical pro- portion of the sexes in young rats, 247 ; on the proportion of the sexes in sheep, 246. , D. G., on Pelecanus ergthro- rhynchus, 390. , Sir W., on the polygamous habits of the Indian wild boar, 218. Ellis, on the prevalence of infiinticide in Polynesia, 592. Elphinstone, Mr., on local differences of stature among the Hindoos, 31 ; on the difficulty of distinguishing the native races of India, 167. Elytra, of the females of Egtiscus, Acilius, Hydroporus, 276. Emberiza, characters of young, 464. miliaria, 464. sclueniclus, 412; head-feathers of the male, 402. Embryo of man, 9, 10 ; of the dog, 10. Embryos of mammals, resemblance of the, 25. Emigration, 137. Emotions experienced by the lower animals in common with man, 69 ; manifested by animals, 71. Emperor moth, 315. Emulation of singing-birds, 369. Emu, sexes and incubation of, 478. Endurance, estimation of, 118. Energy, a characteristic of men, 565. England, numerical proportion of male and female births in, 242. Engleheart, Mr., on the finding of new mates by starlings, 408. 646 ENGLISH. INDEX. FACDLTIES. English, success of, as colonists, 142. Engravers, short-sighted, 33. Entomostraca, 268. Entozoa, difference of colour between the males and females of some, 260. Envy, persistence of, 112. Eocene period, possible divergence of man during the, 156. Eolidse, colours of, produced by the biliary glands, 261. Epeira nigra, small size of the male of, 273 Ephemeral, 274. Ephemeridai, 290. EpMppigcr vitium, stridnlating organs of, 284, 288. Epicalia, sexual differences of colour- ing in the species of, 309. Equus hemionus, winter change of, 542. Eratcina, coloration of, 315. Ercolani, Prof., hermaphroditism in eels, 162. Erect attitude of man, 51, 52. Eristalis, courting of, 280. Eschricht, on the development of hair in man, 18; on a lanuginous moustache in a female foetus, 19 ; on the want of definition between the scalp and the forehead in some children, 151 ; on the arrangement of the hair in the human foetus, 152 ; on the hamness of the face in the human foetus of both sexes, 602, 603. Esmeralda, difference of colour in the sexes of, 294. Esox Indus, 249. reticulatus, 340. Esquimaux, 64, 133 ; their belief in the inheritance of dexterity in seal-catching, 33 ; mode of life of, 197. Estrelda amandava, pugnacity of the male, 366. Eubagis, sexual differences of colour- ing in the species of, 309. Euchirus longimanus, sound produced by, 304. Eudromias morinellus, 477. Eulampis jugularis, colours of the female, 454. Euler, on the rate of increase in the United States, 44. Eumomota superdliaris, racket-shaped feathers in the tail of, 384. Eupetomena macroura, colours of the female, 453. Euphema splendvda, 457. Euplocamus erythrophthalmus, posses- sion of spurs by the female, 364. Europe, ancient inhabitants of, 181. Europeans, difference of, from Hin- doos, 192; hairiness of, probably due to reversion, 601. Eurostopodus, sexes of, 479. Eurygnathus, different proportions of the head in the sexes of, 276. Eustephanus, sexual differences of spe- cies of, 359 ; young of, 487. Exaggeration of natural characters by man, 582. Exogamy, 588, 591. Expression, resemblances in, between man and the apes, 150. Extinction of races, causes of, 181. Eye, destruction of the, 32 ; change of position in, 55 ; obliquity of, regarded as a beauty by the Chinese and Japanese, 578. Eyebrows, elevation of, 13 ; develop- ment of long hairs in, 19 ; in mon- keys, 151 ; eradicated in parts of South America and Africa, 57 5 ;. eradication of, by the Indians of Paraguay, 580. Eyelashes, eradication of, by the In- dians of Paraguay, 580. Eyelids, coloured black, in part of Africa, 574. Eyes, pillared, of the male of Chloeon,. 274; difference in the colour of, in the sexes of birds, 425. Eyton, T. C., observations on the de- velopment of the horns in the fallow-deex’, 234. Eyzies, Les, human remains from, 181. r. Fabre, M., on the habits of Cerceris, 291. Facial bones, causes of modification of the, 55. Faculties, diversity of, in the same race of men, 26 ; inheritance of, 27 ; diversity of, in animals of the same species, 28 ; mental, variation of, in the same species, 66 ; of birds, 410. FAKIRS. INDEX. FISH. 647 Fakirs, Indian, tortures undergone by, 118. Falco leucocephdlus, 484. peregrinus, 408, 461. tinnunculus, 408. Falcon, peregrine, new mate found by, 408. Falconer, H., on the mode of lighting of the Indian elephant, 513 ; on canines in a female deer, 514; on Hgomoschus aqmticus, 547. Falkland Islands, horses of, 181. Fallow-deer, different coloured herds of, 540. Famines, frequency of, among savages, 46. Farr, Dr., on the structure of the uterus, 38 ; on the effects of pro- fligacy, 137 ; on the influence of marriage on mortality, 139, 140. Farrar, F. W., on the origin of lan- guage, 87 ; on the crossing or blend- ing of languages, 91 ; on the absence of the idea of God in cer- tain races of men, 93 ; on early marriages of the poor, 138 ; on the middle ages, 141. Fashions, long prevalence of, among savages, 576, 584. Faye, Prof., on the numerical propor- tion of male and female births in Norway and Russia, 243 ; on the greater mortality of male children at and before birth, 243. Feathers, modified, producing sounds, 377 et aeq., 450 ; elongated, in male birds, 383, 403 ; racket- • shaped, 384 ; barbless and with filamentous barbs in certain birds, 385 ; shedding of margins of, 393. Feeding, high, probable influence of, in the pairing of birds of different species, 415. Feet, thickening of the skin on the soles of the, 33 ; modification of, in man, 52. Felis canadensis, throat-ruff of, 521. pardalxa and F. mitis, sexual ^ differences in the colouring of, 634. Female, behaviour of the, durinc' coui'tship, 222. ° birds, differences of, 470. Females, presence of rudimentary male organs in, 162 ; preference of, for certain males, 214 ; pursuit of, by males, 221 ; occurrence of secondary sexual characters in, 225 ; development of male charac- ters by, 227. Females and males, comparative num- bers of, 213, 215; comparative mor- tality of, while young, 216. Femur and tibia, proportions of, in the Aymara Indians, 34. Fenton, Mr., decrease of Maories, 184 ; infanticide amongst the Maories, 256. Ferguson, Mr., on the courtship of fowls, 417. Fertility lessened under changed con- ditions, 188. Fertilisation, phenomena of, in plants, 222 • in the lower animals, 222. Fevers, immunity of Negroes and Mulattoes from, 193. Fiber zibethicus, protective colouring of it, 542. Fick, H., effect of conscription for militaiy service, 134. Fidelity of savages to one another, 118 ; importance of, 124. Field-slaves, difference of, from house- slaves, 196. Fijians, burying their old and sick parents alive, 102 ; estimation of the beard among the, 581 ; admi- ration of, for a broad occiput, 583. Fiji Archipelago, population of the, 173. Islands, beards of the natives, 560, 581 ; marriage-customs of the, 598. Filial affection, partly the result of natural selection, 105. Filum terminale, 23. Finch, racket-shaped feathers in the tail of a, 384. Finches, spring change of colour in, 393 ; British, females of the, 460. Fingers, partially coherent, in species of Hylobates, 61. Finlayson, on the Cochin Chinese, 578. Fire, use of, 49, 145, 180. Fischer, on the pugnacity of the male of Lethrus cephalotes, 300. Fish, eagerness of male, 221 ; propor- tion of the sexes in, 249 ; sounds produced by, 347. 648 risiiEs. INDEX. FUINGILLID/C:. Fishes, kidneys of, represented by Corpora WolfSaua in the human embryo, 11 ; male, hatching ova in their mouths, 163 ; receptacles for ova possessed by, 208 ; iclative size of the sexes in, 335 ; fresh- water, of the tropics, 343 ; protec- tive resemblances in, 344; change of colour in, 344 ; nest-building, 345 ; spawning of, 345 ; sounds produced by, 347, 566 ; continued growth of, 485. Flamingo, age of mature plumage, 483. Flexor pollicis longus, similar variation of, in man, 42. Flint tools, 145. Flints, difficulty of chipping into form, 49. Floresuga mellivora, 443. Florida, Quiscalus major in, 248. Flounder, coloration of the, 344. Flower, W. H., on the abductor of the fifth metatarsal in apes, 42 ; on the position of the Seals, 150 ; on the Pithecia monachus, 201 ; on the throat-pouch of the male bustard, 373. Fly-catchers, colours and uidification of, 455. Feetus, human, woolly covering of the, 19; arrangement of the hair on, 152. Food, influence of, upon stature, 31. Foot, prehensile power of the, re- tained in some savages, 52 ; pre- hensile, in the early progenitors of man, 160. Foramen, supra - condyloid, excep- tional occurrence of in the humerus of man, 21, 43 ; in the early pro- genitors of man, 160. Forbes, D., on the Aymara Indians, 34; on local variation of colour in the Quichuas, 196 ; on the hair- lessness of the Aymaras and Qui- chuas, 561 ; on the long hair of the Aymaras and Quichuas, 559, 580. Foi'el, F., on white young swans, 282. Formica rufa, size of the cerebral ganglia in, 54. Fossils, absence of, connecting man with the apes, 156. Fowl, occurrence of spurs in the female, 227 ; game, early pugnacity of, 239 ; Polish, early development of cranial peculiarities of, 239; variations in plumage of, 385 ; ex- amples of correlated development in the, 426 ; domestic, breeds and subbreeds of, 460. Fowls, spangled Hamburgh, 229, 238 ; inheritance of changes of plumage by, 229 ; sexual peculiarities in, transmitted only to the same sex, 230 ; loss of secondary sexual cha- racters by male, 231 ; Polish, origin of the crest in, 231 ; period of in- heritance of characters by, 238 ; cuckoo-, 238 ; development of the comb in, 239 ; numerical propor- tion of the sexes in, 247 ; courtship of, 417 ; mongrel, between a black Spanish cock and different hens, 427 ; pencilled Hamburgh, differ- ence of the sexes in, 447 ; Spanish, sexual differences of the comb in, 447 ; spurred, in both sexes, 449. Fox, W. l3., on some half-tamed wild ducks becoming polygamous, and on polygamy in the guinea-fowl and canary-bird, 220 ; on the proportion of the sexes in cattle, 247 ; on the pugnacity of the peacock, 364 ; on a nuptial assembly of magpies, 406 ; on the finding of new mates by crows, 407 ; on partridges living in triplets, 409 ; on the pairing of a goose with a Chinese gander, 415. Foxes, wariness of young, in hunting districts, 80 ; black, 540. Frasei', C., on the difl’erent colours of the sexes in a species of Squillu, 271. , G., colours of Theda, 312. Frere, Hookham, quoting Theognis on selection in mankind, 29. Fringilla cannabina, 394. ciris, age of mature plumage in, 483. cyanea, age of mature plumage in, 483. leucophrys, young of, 486. spinus, 415, tristis, change of colour in, in spring, 393 ; young of, 485. Fringillid.'E, rssemblance of the fe- males of distinct species of, 470. I'ROGS. INDEX. GELASIMDS. 649 Frogs, 349; male, temporary recep- tacles for ova possessed by, 208 ; ready to breed before the females, 212; fighting of, 349 ; vocal organs of, 350. Frontal bone, persistence of the suture in, 39. Fruits, poisonous, avoided by animals, 66. Fuegians, 133, 143 ; difference of sta- ture among the, 31 ; power of sight in the, 33 ; skill of, in stone-throw- ing, 49 ; resistance of the, to their severe climate, 63, 182; mental capacity of the, 65 ; quasi-religious sentiments of the, 95 ; resemblance of, in mental characters, to Euro- peans, 178; mode of life of the, 197 ; aversion of, to hair on the face, 580 ; said to admire European women, 582. Fulgoridae, songs of the, 281. Fur, whiteness of, in arctic animals, in wintei’, 229. Fur-bearing animals, acquired saga- city of, 80. G. Gallicrex, sexual difference in the colour of the irides in, 425. cristatus, pugnacity of male, 360 ; red caruncle occurring in the male during the breeding- season, 339. Gallinaceae, frequency of polygamous habits and of sexual differences in the, 219 ; love-gestures of, 380 ; decomposed feathers in, 385 ; stripes of young, 464 ; comparative sexual difi'erences between the species of, 470, 471 ; plumage of, 472. Gallinaceous birds, weapons of the male, 362 ; racket-shaped feathers on the heads of, 384. Gallinula chloropus, pugnacity of the male, 360. : cristate, pugnacity of the male, 360. Galloperdix, spurs of, 364 ; develop- ment of spurs in the female, 450. GaUophasis, young of, 468. Gallus bankiva, 447 ; neck-hackles of, 392. Stanleyi, pugnacity of the male, 363. Galls, 60. Galton, Mr., on hereditary genius, 28 • gregariousness and independence in animals, 104; on the struggle between the social and personal impulses, 125 ; on the effects of natural selection on civilised na- tions, 133 ; on the sterility of sole^ daughters, 135 ; on the degree ot fertility of people of genius, 136 ; on the early marriages of the poor, 138 ; on the ancient Greeks, 140 ; on the Middle Ages, 141 ; on the progress of the United States, 142 ; on South African notions of beauty, 579. Gammarus, use of the chela of, 268. marinus, 270. Gannets, white only when mature, 492. Ganoid fishes, 159, 165. Gaour, horns of the, 505. Gap between man and the apes, 156. Gaper, sexes and young of, 486. Gardner, on an example of rationality in a Gelasimus, 270. Garrulus glandarius, 407. Gartner, on sterility of hybrid plants, 172. Gasteropoda, 272 ; pulmoniferous, courtship of, 262. Gasterosteus, 220 ; nidification of, 345. ■ leiurus, 331, 340, 345. trachurus, 332. Gastrophora, wings of, brightly co- loured beneath, 315. Gauchos, want of humanity among the, 123. Gaudry, M., on a fossil monkey, 154. Gavia, seasonal change of plumage in, 493. Geese, clanging noise made by, 368 pairing of different species of, 415 ; Canada, selection of mates by, 416. Gegenbaur, C., on the number of digits in the Ichthyopterygia, 37 ; on the hermaphroditism of the remote progenitors of the verte- brata, 161 ; two types of nipple in mammals, 162. Gelasimus, proportions of the sexes in a species of, 354 ; use of the enlarged chelae of the male, 268 ; pugnacity of males of, 269; rational 0EMMCLK3. INDEX. GONEITERYX. 650 actions of a, 270; difference of colour in the sexes of a species of, 271. Geramules, dormant in one sex, 231. Genius, 28 ; hereditary, 564. ■ , fertility of men and women of, 136. Geoffroy-Saint-Hilaire, Isid., on the recognition of women by male quadrumana, 8; on monstrosities, 30 ; coincidences of arrested devel- opment with polydactylism, 37 ; on animal-like anomalies in the human structure, 40 ; on the cor- relation of monstrosities, 44; on the distribution of hair in man and monkeys, 57 ; on the caudal ver- tebrse of monkeys, 58 ; on cor- related variability, 60 ; on the classification of man, 147 ; on the long hair on the heads of species of Semnopithecus, 151 ; on the hair in monkeys, 152; on the develop- ment of horns in female deer, 504 ; and F. Cuvier, on the mandrill, 539 ; on Hylobates, 558, 559. Geographical distribution, as evidence of specific distinctions in man, 169. Geometiae, brightly coloured beneath, 315. Goophagus, frontal protuberance of male, 340, 345; eggs hatched by the male, in the mouth or bran- chial cavity, 345. Georgia, change of colour in Germans settled in, 196. Geotrupes, stridulation of, 303, 304. Gerbe, M., on the nest-building of Crenilahrus massa and C. melops, 345. Gerland, Dr., on the prevalence of infanticide, 117, 577, 592 ; on the extinction of races, 182. Gei-vais, P., on the hairiness of the gorilla, 57 ; on the mandrill, 538. Gesture-language, 178. Ghost-moth, sexual difference of colour in the, 316. Gibbs, Sir D., on differences of the voice in different races of men, 566. Gibbon, Hoolock, nose of, 150. Gibbons, voice of, 527. Gill, Dr., male seals larger than females, 219 ; sexual differences in seals, 515 Giraffe, its mode of using the horns, 508 ; mute, except in the rutting season, 526. Girard, M., disputes descent of vcrti- brates from Ascidians, 160 ; colour of sponges and Ascidians, 261 ; musky odour of Sphinx, 308. Giraud-Teulon, on the cause of short sight, 34. Glanders, communicable to man from the lower animals, 7. Glands, odoriferous, in mammals, 529, 530. Glareola, double moult in, 390. Glomeria limbata, difference of colour in the sexes of, 274. Glow-worm, female, apterous, 208 ; luminosity of the, 277. Gnats, dances of, 280 ; auditory powers of, 569. Gnu, sexual differences in the colour of the, 536. Goat, male, wild, falling on his horns, 508 ; male, odour emitted by, 529 ; male, wild, crest of the, 531 ; Berbura, mane, dewlap, &c., of the male, 532 ; Kemns, sexual differ- ence in the colour of the, 536. Goats, sexual differences in the horns of, 230 ; horns of, 235, 505 ; mode of fighting of, 508 ; domestic, sexual differences of, late developed, 237 ; beards of, 531. Goatsucker, Virginian, pairing of the, 366. Gobies, nidification of 345. God, want of the idea of, in some races of men, 93. Godron, M., on variability, 29 ; on difference of stature, 31 ; on the want of connexion between climate and the colour of the skin, 192 ; on the odour of the skin, 198 ; on the • colour of infants, 558. Goldfinch, 371, 394; proportion of the sexes in the, 248 ; sexual dif- ferences of the beak in the, 359 ; courtship of the, 401. , North American, young of, 485 Gold-fish, 342. Gotnphus, proportions of the sexes in, 254; dill’erence in the sexes of, 290. Goncpteryx Jthamni, 312 ; sexual dif- ference of colour in, 322. GOODSIR, INDEX. GRAr. 651 Goodsil', Prof., on the affinity of the lancelet to the ascidians, 159. Goosander, young of, 467. Goose, Antarctic, colours of the, 492. , Canada, pairing with a Ber- nicle gander, 414. , Chinese, knob on the beak of the, 426. , Egyptian, 364. , Sebastopol, plumage of, 385. , Snow-, whiteness of the, 492. , Spur-winged, 364. Gorilla, 561 ; semi-erect attitude of the, 52 ; mastoid processes of the, 53 ; direction of the hair on the arms of the, 151 ; manner of sit- ting, 151 ; supposed to be a kind of mandrill, 177 ; polygamy of the 217, 590, 591 ; voice of the, 527 ; cra- nium of, 558 ; fighting of male, 562. Gosse, P. H., on the pugnacity of the male Humming-bird, 360. , M., on the inheritance of artifi- cial modifications of the skull, 603. Gould, B. A., on variation in the length of the legs in man, 26 ; measurements of American soldiers, 30, 32 ; on the proportions of the body and capacity of the lungs in different races of men, 167 ; on the the inferior vitality of mulattoes, 171. , J., on migration of swifts, 108 ; on the arrival of male snipes before the females, 212; on the numerical proportion of the sexes in birds, 247 ; on Neomorpha Grypus, 359 ; on the species of Eustephanus, 359 ; on the Australian musk-duck, 359 ; on the relative size of the sexes in Briziura lobata and Cincloramphus cruralis, 362 ; on Lobivanellus loha- tus, 366 ; on the habits of Menura Alberti, 371 ; on the rarity of song | in brilliant birds, 371 ; on Selas- ' phorus platycercus, 378; on the Bower-birds, 381, 406; on the ornamental plumage of the Hum- ming-birds, 387 ; on the moulting of the ptarmigan, 392 ; on the dis- play of plumage by the male Hum- ming-birds, 394 ; on the shyness of adorned male birds, 403; on the decoration of the bowers of Bower- birds, 413; on the decoration of their nests by Humming-birds, 413 ; on variation in the g^nus Cynan- thus, 423 ; on the colour of the thighs in a male parakeet, 424 ; on Urosticte Benjainini, 442, 443 ; on the nidification of the Orioles, 454 ; on obscurely-coloured birds build- ing concealed nests, 454; ontrogons and kingfishers, 456 ; on Austra- lian parrots, 458 ; on Australian pigeons, 458 ; on the moulting of the ptarmigan, 462 ; on the imma- ture plumage of birds, 466 et seq. ; on the Australian species of Turnie, 473 ; on the young of AUhurus poly- tmus, 487 ; on the colours of the bills of toucans, 491 ; on the relative size of the sexes in the marsupials of Australia, 515 ; on the colours of the Marsupials, 533. Goureaux, on the stridulation of Mu- tilla europcea, 293. Gout, sexually transmitted, 237. Graba, on the Pied Ravens of the Feroe Islands, 424 ; variety of the Guillemot, 424. Gradation of s’econdaiy sexual cha- racters in birds, 430. Grallatores, absence of secondary sexual characters in, 219 ; double moult in some, 390. Grallina, nidification of, 454. Grasshoppers, stridulation of the, 286. Gratiolet, Prof., on the anthropo- morphous apes, 154 ; on the evo- lution of the anthropomorphous apes, 177 ; on the diffex’ence in the development of the brains of apes and of man, 203. Gray, Asa, on the gradation of species among the Composita;, 175. , .1. E., on the caudal vertebrae of monkeys, 58 ; on the presence of rudiments of horns in the female of Cermlits moschatus, 504; on the horns of goats and sheep, 505 ; on the beard of the ibex, 531 ; on the Berbura goat, 533 ; on sexual dif- ferences in the coloration of Rodents, 534 ; ornaments of male sloth, 534; on the colours of the Elands, 535 , on the Sing-sing antelope, 536 ; on the colours of goats, 536 ; on the hog-deer, 546. 6S2 GREATEST. mDEX. nACKEE. “ Greatest happiness principle,” 120, 121. Greeks, ancient, 140. Green, A. H., on beavers fighting, 500 ; on the voice of the beaver, 527. Greenfinch, selected by a female canary, 415. Greg, W. R., on the effects of natural selection on civilised nations, 133 ; on the early marriages of the poor, 138 ; on the Ancient Greeks, 141. Grenadiers, Prussian, 29. Greyhounds, numerical proportion of the sexes in, 215, 21(5 ; numerical proportion of male and female births in, 246, 258. Grouse, red, monogamous, 219 ; pug- nacity of young male, 366 ; pro- ducing a sound by scraping their wings npon the ground, 374 ; dura- tion of courtship of, 405 ; colours and nidification of, 455. Gruber, Dr., on the occurrence of the supra-condyloid foramen in the humerus of man, 21 ; on division of malar bone, 39 ; stridulation of locust, 284. Grus americanus, age of mature plu- mage in, 483; breeding in im- mature plumage, 484. virgo, trachea of, 374. Gryllus campestris, 284; pugnacity of male, 289. doniesticus, 284. Grypus, sexual differences in the beak in, 359. Guanacoes, battles of, 500 ; canine teeth of, 514. Guanas, strife for women among the, 562 ; polyandry among the, 593. Guanche skeletons, occurrence of the supra-condyloid foramen in the humerus of, 22. Guaranys, proportion of men and women among, 244 ; colour of new- born children of the, 557 ; beards of the, 561. Guende, A., on the sexes of Hypery- thra, 251. Guilding, L., on the stridulation of the Locustida:, 283. Guillemot, variety of the, 424. Guinea, sheep of, with males only horned, 234. Guinea-fowl, monogamous, 219 ; occa- sional polygamy of the, 220; markings of the, 429. Guinea-pigs, inheritance of the efiects of operations by, 603. Gulls, seasonal change of plumage in, 492 ; white, 492. Gunther, Dr., on paddle of Ceratodas, 37 ; on hermaphroditism in Serra- nus, 162 ; on male fishes hatching ova in their mouths, 163, 345 ; on mistaking infertile female fishes for males, 249 ; on the prehensile organs of male Plagiostomous fishes, 331 ; spines and brushes on fishes, 331 ; on the pugnacity of the male salmon and trout, 332 ; on the relative size of the sexes in fi.shes. 335 ; on sexual differences in fishes, 336 et seq. ; on the genus Callio- nymus, 337 ; on a protective re- semblance of a pipe-fish, 344 ; on the genus Solcnostotna, 346 ; on the coloration of frogs and toads, 349 ; combat of Testudo elegans, 351 ; on the sexual differences in the Ophidia, 351 ; on differences of the sexes of lizards, 354 et seq. Gynanisa Isis, ocellated spots of, 428. Gypsies, uniformity of, in various parts of the world, 193. H. Habits, bad, facilitated by familiarity, 123 ; variability of the force of, 125. Hiickel, E., on the origin of man, 3 ; on rudimentary characters, 11 ; on death caused by inflammation of the vermiform appendage, 21 ; on the canine teeth in man, 40 ; on the steps by which man became a biped, 52 ; on man as a member of the Catarrhine group, 155 ; on the position of the Lemuridae, 157 ; on the genealogy of the Mammalia, 158 ; on the lancelet, 159 ; on the transparency of pelagic animals, 261 ; on the musical powers of women, 573. HAGEN. INDEX. HEHITRAGUS. 653 Hagen, H., and Walsh, B. D., on Anaerican Neuroptera, 254. Hair, development of, in man, 18 ; character of, supposed to be deter- mined by light and heat, 32 ; distri- bution of, in man, 57, 600 ; possibly removed for ornamental purposes, 58 ; arrangement and direction of, 151 ; of the early progenitors of man, 160 ; different texture of, in distinct races, 167 ; and skin, cor- relation of colour of, 197 ; develop- ment of, in mammals, 530 ; manage- ment of, among different peoples, 575 ; great length of, in some North American tribes, 580 ; elon- gation of the, on the human head, 603. Hairiness, difference of, in the sexes in man, 559 ; variation of, in races of men, 559. Hairs and excretory pores, numerical relation of, in sheep, 198. Hairy family, Siamese, 601. Halbertsma, Prof., hermaphroditism in Serranus, 162. Hamadryas baboon, turning over stones, 101 ; mane of the male, 521. Hamilton, G., on the cruelty of the Kaffirs to animals, 118 ; on the engrossment of the women by the Kaffir chiefs, 595. Hammering, difficulty of, 49. Hancock, A., on the colours of the nudibranch Mollusca, 261, 264. Hands, larger at birth, in the chil- dren of labourers, 33 ; structure of, in the quadrumana, 50 ; and arms, freedom of, indirectly correlated with diminution of canines, 53. Handwriting, inherited, 88. Handyside, Dr., supernumerary mam- ma: in men, 37. Harcourt, E. Vernon, on Fringilla cannabina 394. JIarelda glacialis, 420. Hare, protective colouring of the, 542. Hares, battles of male, 500. Harlan, Dr., on the difference be- tween field- and house-slaves, 196. Harris, J. M., on the relation of com- plexion to climate, 195. , T. W., on the Katy-did locust, 283 ; on the stridulation of the grasshoppers, 286 ; on (Ecanthus nivalis, 289 ; on the colouring of Lepidoptera, 314 ; on the colouring of Saturnia lo, 316. Harting, spur of the Ornithorhynchus, 502. Hartman, Dr., on the singing of Cicada septondecim, 282. Hatred, persistence of, 112. Haughton, S., on a variation of the flexor pollicis longus in man, 42. Hawks, feeding orphan nestling, 409. Hayes, Dr., on the diverging of sledge- dogs on thin ice, 75. Haymond, R., on the drumming of the male Tetrao •umbellus, 375 ; on the drumming of birds, 37 6. Head, altered position of, to suit the erect attitude of man, 55 ; hairiness of, in man, 57 ; processes of, in male beetles, 295 ; artificial alte- rations of the form of the, 583. Hearne, on strife for women among the North American Indians, 361 ; on the North American Indians’ notion of female beauty, 578 ; re- peated elopements of a North Ame- rican woman, 597. Heart, in the human embryo, 9. Heat, supposed effects of, 32. Hectocotyle, 263. Hedge-warbler, 473 ; voung of the, 481. Heel, small projection of, in the Aymara Indians, 35. Hegt, M., on the development of the spurs in peacocks,. 236. Heliconidse, 308 ; mimicry of, by other butterflies, 323. Ueliopathes, stridulation peculiar to the male, 305. Ileliothrix auriculata, vouna: of, 467, 468. Helix pomatia, example of individual attachment in, 263. Hellins, J., proportions of sexes of Lepidoptera reared by, 253. Helmholtz, on pleasure derived from harmonies, 92 ; on the vibration of the auditory hairs of Crustacea, 568; the physiology of harmony. 659. Hemiptera, 281. Hermtragus, beai'dless in both sexes, 531, IIEMSBACH. INDEX. H0H8ES. 654 Herasbach, M. von, on medial mamma in man, 37. Hepburn, Mr., on the autumn song of the water-ouzel, 370. Hepialus humuli, sexual difference of colour in the, 316. Herbs, poisonous, avoided bv .animals, 66. Hermaphroditism of embryos, 161. Herodias bubulcus, vernal moult of, 393. Heron, Sir R., on the habits of pe.a- fowl, 418, 419, 443. love-gestures of a, 380 Herons, decomposed feathers in, 385 ; breeding plumage of, 391, 392 ; young of the, 481 ; sometimes dimorphic, 484 ; continued growth of crest and plumes in the males of some, 485 ; change of colour in some, 494. Hesperomys cognatus, 568. Hetmrina, proportion of the sexes in, 254 ; difference in the sexes of, 290. Ueterocerus, stridulation of, 302. Hewitt, Mr., on a game-cock killing a kite, 363 ; on the recognition of dogs and cats by ducks, 412 ; on the pairing of a wild duck with a pintail drake, 415 ; on the court- ship of fowls, 417 ; on the coupling of pheasants with common hens, 420. Hilgendorf, sounds produced by crus- taceans, 274. Hindoo, his horror of breaking his caste, 122, 124. Hindoos, loc.al difference of stature among, 31 ; difference of, from Europeans, 192 ; colour of the beard in, 558. Hipparchia Janira, 319; instability of the ocellated spots of, 428. Hippocampus, development of, 163 ; marsupial receptacles of the male, 346. minor, 202. Hippopotamus, nakedness of, 56. Hips, proportions of, in soldiers and sailors, 32. Hodgson, S., on the sense of duty, 97. Hoffberg, on the horns of the rein- deer, 503 ; on sexual pi’eferences shown by reindeer, 525. Hoffman, Prof., protective colours 281 ; fighting of frogs, 350. Hog-deer, 546 Hog, wart-, 519 ; river-, 520. Holland, Sir H., on the effects of new diseases, 182. Homologous structures, correlated variixtion of, 43. Homoptera, 281 ; stridulation of the, and Orthoptera, discussed, 28«. Honduras, Quiscalus major in, 248. Honey-buzzard of India, variation in the crest of, 424. Honey-suckers, moulting of the, 392 . Australian, nidificatiou of, 454. Honour, law of, 121. Hooker, Dr., forbearance of elephant to his keeper, 104 ; on the colour of the beard in man, 558. Hookham, Mr., on mental concepts in animals, 83. Hoolock Gibbon, nose of, 150. Hoopoe, 371; sounds produced by the male, 376. Hoplopterus armatus, wing-spurs of, 366. Hornbill, African, inflation of the neck-wattle of the male during courtship, 383. Hornbills, sexual difference in the colour of the eyes in, 425 ; nidifi- cation and incubation of, 454. Horne, C., on the rejection of a brightly-coloured locust by lizards and birds, 289. Horns, sexual differences of, in sheep and goats, 230 ; loss of, in female merino sheep, 231 ; development of, in deer, 233; development of, in antelopes, 234; from the head and thorax, in male beetles, 297 ; of deer, 503, 506, 515 ; and canine teeth, inverse development of, 514. Horse, fossil, extinction of the, in South America, 191; polygamous, 217 ; canine teeth of male, 502 ; winter change of colour, 542. Horses, rapid increase of, in South America, 47 ; diminution of canine teeth in, 53 ; dreaming, 74 ; of the Falkland Islands and Pam- pas, 181 ; numerical proportion of the sexes in, 215, 216; lighter in winter in Sibcri.a, 229 ; sexual HOTTENTOT. INDEX. HYDROPORUS. 65 5 preferences in, 524; pairing pre- ferently with those of the same colour, 540; numerical proportion of male and female births in, 245 ; formerly striped, 547. Hottentot women, peculiarities of,174. Hottentots, lice of, 170; readily be- come musicians, 570 ; notions of female beauty of the, 578; com- pression of nose by, 583. Hough, Dr. S., men’s temperature more variable than women’s, 224 ; proportion of sexes in man, 243. House-slaves, difference of, from field- slaves, 196. Houzeau, on the baying of the dog, 75; on reason in dogs, 76; birds killed by telegraph wires, 80 ; on the dies of domestic fowls and parrots, 85, 87 ; animals feel no pity, 102 ; suicide in the Aleutian islands, 117. Howorth, H. H., extinction of savages, 183. Huber, P., on ants playing together, 69 ; on memory in ants, 74; on the intercommunication of ants, 89 ; on the recognition of each other by ants after separation, 292. Hue, on Chinese opinions of the ap- pearance of Europeans, 578. Huia, the, of New Zealand, 208. Human, man classed alone in a, king- dom, 147. sacrifices, 96. Humanity, unknown among some •savages, 118 ; deficiency of, among savages, 123. Humboldt, A. von, on the rationality of mules, 78 ; on a parrot preserv- ing the language of a lost tribe, 181 ; on the cosmetic arts of savages, 574 ; on the exaggeration of natural characters by man, 582 ; on the red painting of American Indians, 583. Hume, D., on sympathetic feelings, 109. Humming-bird, racket-shaped feathers in the tail of a, 384; display of plumage by the male, 394. Humming-birds, ornament their nests, 92, 413; polygamous, 219; pro- portion of the sexes in, 248, 488 ; sexual differences in, 359, 442 ; pugnacity of male, 360; modified primaries of male, 378 ; coloration of the sexes of, 387 ; display by, 443 ; nidification of the, 453 ; colours of female, 453 ; young of, 487. Humphreys, H. N., on the habits of the stickle-back, 220, 332. Hunger, instinct of, 112. Huns, ancient, flattening of the nose by the, 583. Hunter, J., on the number of species of man, 174; on secondary sexual characters, 207 ; on the general behaviour of female animals during courtship, 222 ; on the muscles ot the larynx in song-birds, 371; on the curled frontal hair of the bull, 531 ; on the rejection of an ass by a female zebra, 540. Hunter, W. W., on the recent rapid increase of the Santali, 45 ; on the Santali, 192. Huss, Dr. Max, on mammary glands, 162. Hussey, Mr., on a partridge distin- guishing persons, 412. Hutchinson, Col., example of reason- ing in a retriever, 78. Hutton, Capt., on the male wild goat falling on his horns, 507. Huxley, T. H., on the structural agreement of man with the apes, 2 ; on the agreement of the brain in man with that of lower animals, 6 ; on the adult age of the orang, 8 ; on the embryonic development of man, 9 ; on the origin of man, 3, 11 ; on variation in the skulls of the natives of Australia, 26; on the abductor of the fifth meta- tarsal in apes, 42 ; on the nature of the reasoning power, 77 ; on the position of man, 150 ; on the sub- orders of primates, 152; on the Lemuridae, 157 ; on the Dinosauria, 158 ; on the amphibian affinities of the Ichthyosaurians, 159 ; on vari- ability of the skull in certain races of man, 174; on the races of man, 176 ; supplement on the brain, 199. Hybrid birds, production of, 414. Hydrophobia communicable between man and the lower animals, 7. Ilydroporus, dimorphism of femalea of, 276. HYELAPHUS. INDEX. iKSEcrrrvop.A, Hyelaphus porcinus, 546. Hygrogonus, 345. Hyla, singing species of, 350. Hyldbatcs, absence of the thumb in, 51 ; upright progression of some species of, 52 ; maternal affection in a, 70; direction of the hair on the arms of species of, 151 ; females of, less hairy below than males, 558. • agilis, 51 ; hair on the arms of, 151 ; musical voice of the, 527 ; superciliary ridge of, 558 ; voice of, 567. hoolooh, sexual difference of colour in, 537. Jar, 51 ; hair on the arms of, 151. laitciscus, 51 ; song of, 568. syndactylus, 51 ; laryngeal sac of, 527. Hylophila prasinana, 308. Hyraenoptera, 291 ; large size of the cerebral ganglia in, 54; classifica- tion of, 148 ; sexual differences in the wings of, 277 ; aculeate, rela- tive size of the sexes of, 279. Hymenopteron, parasitic, with a sedentary male, 221. Ilyomoschus aquations, 547. Hyperythra, proportion of the sexes in, 251. Hypogymna dispar, sexual difference of colour in, 316. Eypopyra, coloration of, 315. I. Ibex, male, falling on his horns, 508 ; beard of the, 531. Ibis, white, change of colour of naked skin in, during the breeding season, 389 ; scarlet, young of the, 481. tantalus, age of mature plumage in, 483 ; breeding in immature plumage, 484. Ibises, decomposed feathers in, 385 ; white, 492 ; and black, 493. Ichneumomda:, diiierence of the sexes in, 292. Ichthyopterygia, 37. Ichthyosaurians, 159. Idiots, . microcephalous, their charac- ters and habits, 35 ; hairiness and animal nature of their actions, 36 ; microcephalous, imitative faculties of, 87. Igtiana tubcroulata, 354. Iguanas, 354. Illegitimate and legitimate children, proportion of the sexes in, 244. Imagination, existence of, in animals, 74. Imitation, 68 ; of man by monkeys, 72 ; tendency to, in monkeys, micro- cephalous idiots and savages, 87 ; influence of, 129. Immature plumage of birds, 463, 466. Implacentata, 157. Implements, employed by monkeys, 81 ; fashioning of, peculiar to man, 82. Impregnation, period of, influence of, upon sex, 245. Improvement, progressive, man alone supposed to be capable of, 79. Incisor teeth, knocked out or filed by some savages, 575. Increase, rate of, 44 ; necessity of checks in, 47. Indecency, hatred of, a modern virtue, 119. India, difficulty of distinguishing the native races of, 167 ; Cyprinida: of, 343; colour of the beard in races of men of, 558. Indian, North American, honoured for scalping a man of another tribe. 117. Individuality, in animals, 83. Indopicus carlotta, colours of the sexes of, 458. Infanticide, prevalence of, 46, 117, 256 ; supposed cause of, 677 ; pre- valence and causes of, 591 et seq. Inferiority, supposed physical, of man, 64. Inflammation of the bowels, occur- rence of, in Cebus Azarm, 7. Inheritance, 27 ; of long and short sight, 33 ; of effects of use of vocal and mental organs, 83 ; of moral tendencies, 123, 126; laws of, 227; sexual, 232; sexually limi- ted, 444. Inquisition, influence of the, 141. Insanity, hereditary, 28. Insect, fossil, from the Devonian, 289. Insectivora, 534; absence of secondary sexual characters in, 218. INSECTS. INDEX. JERDON. 657 Insects, relative size of the cerebral ganglia in, 54; male, appearance of, before the females, 212 ; pursuit of female, by the males, 221 ; period of development of sexual characters in, 236; secondary sexual cha- racters of, 274 ; stridulation, 566. Insessores, vocal organs of, 370. Instep, depth of, in soldiers and sailors, 32. Instinct and intelligence, 67. , migratory, vanquishing the maternal, 107, 113. Instinctive actions, the result of in- heritance, 105. impulses, difference of the force of, 110, 111; and moral impulses, alliance of, 110. Instincts, 66 ; complex origin of, through natural selection, 67 ; possible origin of some, 67 ; ac- quired, of domestic animals, 104 ; variability of the force of, 107 ; difference of force between the social and other. 111, 126 ; utilised for new purposes, 571. lustrumenta) music of birds, 375, 378. Intellect, influence of, in natural selection in civilised society, 136. Intellectual faculties, their influence on natural selection in man, 127 ; probably perfected through natural selection, 128. Intelligence, Mr. H. Spencer on the dawn of, 67. Intemperance, no reproach among savages, 119; its destructiveness, 137. Intoxication in monkeys, 7. Iphias glaucippe, 313. Iris, sexual difference in the coionr of the, in birds, 383, 425. Ischio-pubic muscle, 41. Ithaginis crucntus, number of spurs in, 364. lulus, tarsal suckers of the males of, 274 J. Jackals learning from dogs to bark, 73. Jack-snipe, coloration of the, 491 Jacquinot, on the number of species of man, 174. Jaeger, Dr., length of bones increased from carrying weights, 32 ; on the difficulty of approaching herds of wild animals, 100 ; male Silver- pheasant, rejected when his plu- mage was spoilt, 419. Jaguars, black, 539. Janson, E. W., on the proportions of the sexes in Tomicus villosus, 253 ; on stridulant beetles, 302. Japan, encouragement of licentious- ness in, 46. Japanese, general beardlessness of the, 560 ; aversion of the, to whiskers, 581. Jardine, Sir W., on the Argus phea- sant, 384, 403. Jarrold, Dr., on modifications of the skull induced by unnatural position, 56. Jarves, Mr., on infanticide in the Sandwich Islands, 257. Javans, relative height of the sexes of, 559 ; notions of female beauty, 580. Jaw, influence of the muscles of the, upon the physiognomy of the apes, 54. Jaws, smaller proportionately to the extremities, 33 ; influence of food upon the size of, 33 ; diminution of, in man, 53 ; in man, reduced by correlation, 562. Jay, young of the, 481 ; Canada, young of the, 481. Jays, new mates found by, 407 ; dis- tinguishing persons, 412. Jeffreys, J. Gwyn, on the form of the shell in the sexes of the Gastero- poda, 262 ; on the influence of light upon the colours of shells, 263. Jelly-fish, bright colours of some, 260. Jenner, Dr., on the voice of the rook, 375 ; on the finding of new mates by magpies, 407 ; on retardation of the generative functions in birds, 409. Jenyns, L., on the desertion of their young by swallows, 108 ; on male birds singing after the proper season, 409. Jerdon, Dr., on birds dreaming, 74; on the pugnacity of the male bul- bul, 360 ; on the pugnacity of the m.ale Ortygomis gularis, 363 ; on the spurs of Galloperdix, 364 ; on 2 U 658 JEVONS. INDEX. KiaBy. tho habits of Ldbimnellus, 366 ; on the spoonbill, 374; on the drum- ming of the Kalij-pheasant, 376 ; on Indian bustards, 378; on Otis bengalensis, 381 ; on the ear-tufts of Sypheotides auritus, 384 ; on the double moults of certain birds, 391 ; on the moulting of the honey- suckers, 392 ; on the moulting of bustards, plovers, and drongos, 393 ; on the spring change of colour in some finches, 393 ; on display in male birds, 394 ; on the display of the under-tail coverts by the male bulbul, 402 ; on the Indian honey- buzzard, 424 ; on sexual differences in the colour of the eyes of horn- bills, 425 ; on the markings of the Tx-agopan pheasant, 428 ; on the nidification of the Orioles, 453 ; on the nidification of the hoimbills, 454 ; on the Sultan yellow-tit, 458 ; on PalcBomisjavanicus, 461 ; on the immature plumage of birds, 465 et seq. ; on representative species of birds, 468 ; on the habits of Turnix, 476 ; on the continued increase of beauty of the peacock, 485; on coloi'ation in the genus Falceomis, 494. Jevons, W. S., on the migrations ot man, 47. Jews, ancient use of flint tools by the, 145 ; uniformity of, in various parts of the world, 193 ; numerical pi'oportion of male and female births among the, 243 ; ancient, tattooing practised by, 574. Johnstone, Lieut., on the Indian ele- phant, 218. Jollofs, fine appearance of the, 587. Jones, Albert, px'oportion of sexes of Lepidoptera, reai'ed by, 253. Juan Fernandez, humming-birds of, 487. Junonia, sexual differences of colour- ing in species of, 310. Jupitei-, comparison with Assyrian effigies, 581. K. Kaffir skull, occurrence of the dia- stema in a, 40. Kaffirs, their cruelty to animals, 118 ; lice of the, 170 ; colour of ^he, 579 ; engrossment of the hand- somest women by the chiefs of the, 595 ; marriage-customs of the, 598. Kalij-pheasant, drumming of the male, 375 ; young of, 468. Kallima, resemblance of, to a withered leaf, 311. Kalmucks, general beardlessness of, 560 ; aversion of, to hairs on the face, 581 ; maridage-customs of the, 598. Kangaroo, gi'eat red, sexual difference in the colour of, 533. Kant, Imm., on duty, 97 ; on self- restraint, 110; on the number of species of man, 174. Katy-did, striduiation of the, 283. Keen, Dr., on the mental powers of snakes, 352. Keller, Dr., on the difficulty of fashioning stone implements, 49. Kent, W. S., elongation of dorsal fin of Callvonymus lyra, 336 ; court- ship of Labrus mixtus, 341 ; colours and courtship of Cuntharus lineatus. 341. Kestrels, new mates found by, 408. Kidney, one, doing double work in disease, 32. King, W. R., on the vocal organs of Tetrao eupido, 371 ; on the drum- ming of grouse, 376 ; on the rein- deei', 503; on the attraction of male deer by the voice of the female, 526. King and Fitzroy, on the marriage- customs of the Fuegians, 599. King-crows, nidification of, 453. Kingfisher, 371; racket-shaped feathers in the tail of a, 384. Kingfishers, coloui's and nidification of the, 455, 457, 459 ; immature plumage of the, 467, 468 ; young of the, 481. King Lory, 457 ; immatui'e plumage of the, 467. Kingsley, C., on the sounds pi-oduced by Umbrina, 347. Kirby and Spence, on sexual differ- ences in the length of the snout in Curculionidse, 208; on the court- ship of insects, 221 ; on the elytra of Vytiscus, 276 ; on peculiarities in the legs of male insects, 276 : KITE. INDEX. LANIUa 659 on the relative size of the sexes in insects, 279 ; on the Fulgoridae, 281 ; on the habits of Termites, 291 ; on difference of colour in the sexes of beetles, 294 ; on the horns of the male laraellicorn beetles, 297 ; on hornlike processes in male Cnrculionidas, 299 ; on the pug- nacity of the male stag-beetle, 299. Kite, killed by a game-cock, 363. Knot, retention of winter plumage by the, 391 Knox, R., on the semilunar fold, 17 ; on the occurrence of the supra- condyloid foramen in the humerus of man, 21 ; on the features of the young Memnon, 168. Koala, length of the ccecum in, 20. Kobus ellipsiprymnus, proportion of the sexes in, 247. Kolreuter, on the sterility of hybrid plants, 172. Koodoo, development of the horns of the, 234 ; markings of the, 543. Koppen, F. T., on the migratory lo- cust, 283. Kordofan, protuberances artificially produced by natives of, 574. Koraks, marriage customs of, 598. Korte, on the proportion of sexes in locusts, 254 ; Russian locusts, 283. Kovalevsky, A., on the aflinity of the Ascidia to the Vertebrata, 159, 160. , W., on the pugnacity of the male capercailzie, 363 ; on the pairing of the capercailzie, 367. Krause, on a convoluted body at the extremity of the tail in a Macacus and a cat, 23. Kupffer, Prof., on the affinity of the Ascidia to the Vertebrata, 160. L. Lahidocera Darminii, prehensile organs of the male, 266 Lahrus, splendid colours of the species of, 342. mixtus, sexual differences in, 337, 341. pavo, 342. Lacertilia, sexual differences ( f, 354. I.afresnaye, M. de, on birds of para- dise, 385. Lamarck, on the origin of man, 3. Lamellibranchiata, 262. Laraellicorn beetles, horn-like pro- cesses from the head and thora.r of, 295, 298 ; influence of sexual selec- tion on, 301. Lamellicornia, stridulation of, 303. Lament, Mr., on the tusks of the walrus, 502 ; on the use of its tusks by the walrus, 513 ; on the bladder-nose seal, 528. Lampornis porphyrurus, colours of the female, 454. Lampyridae, distasteful to mammals, 277. Lancelot, 159, 165. Landois, H., gnats attracted by sound, 280 ; on the production of sound by the Cicadse, 281 ; on the stridu- lating organ of the crickets, 284 ; on Decticus, 285 ; on the stridula- ting organs of the Acridiidae, 286 ; stridulating apparatus in Orthop- tera, 288 ; sounds produced by Atropus, 291 ; on the stridulation of Necrophorus, 302 ; on the stridu- lant organ of Cerambyx heros, 303 ; on the stridulant organ of Geo- trupes, 303 ; on the stridulating organs in the Coleoptera, 304; on the ticking of Anobium, 306. Landor, Dr., on remorse for not obey ing tribal custom, 114. Language an art, 86 ; articulate, origin of, 86 ; relation of the progress of, to the development of the brain, 87 ; effects of inheritance in pro- duction of, 88 ; complex structure of, among barbarous nations, 91 ; natural selection in, 91 ; gesture. 178 ; primeval, 180 ; of a lost tribe preserved by a parrot, 181, Languages, presence of rudiments in, 90 ; classification of, 90 ; variability of, 90 ; crossing or blending of, 90 ; complexity of, no test of perfection or proof of special creation, 92 ; re- semblance of, evidence of commu- nity of origin, 148. and species, identity of evidence of their gradual development, 90. Lanius, 462 ; characters of young, 464. rufus, anomalous young of, 482. 2 u 2 660 LANKE8TER. INDEX. LIRELUJUDjE. Lankester, E. R., on comparative lon- gevity, 133, 136 ; on the destruc- tive effects of intemperance, 137. Lanugo, of the human foetus, 19, 600. Lapponian language, highly artificial, 91. Lark, proportion of the sexes in the, 248 ; female, singing of the, 370. Larks, attracted by a mirror, 413. Lartet, E., comparison of cranial ca- pacities of skulls of recent and tertiary mammals, 55 ; on the size of the bruin in mammals, 81; on Dryopithecus, 155 ; on pre-historic flutes, 570. Lams, seasonal change of plumage in, 492. Larva, luminous, of a Brazilian beetle, 278. Larynx, muscles of the, in song-birds, 371. Lasiocampa quercus, attraction of males by the female, 252 ; sexual difference of colour in, 316. Latham, R. G., on the migrations of man, 48. Latooka, perforation of the lower lip by the women of, 576. Laurillard, on the abnormal division of the malar bone in man, 39. Lawrence, W., on the superiority of savages to Europeans in power of sight, 33 ; on the colour of negro infants, 558 ; on the fondness of savages for ornaments, 578 ; on beardless races, 581 ; on the beauty of the English aristocracy, 586. Layard, E. L., on an instance of ra- tionality in a cobra, 352 ; on the pugnacity of Gallus Stanlcyi, 363. Laycock, Dr., on vital periodicity, 8 ; theioid nature of idiots, 36. Leaves, autumn, tints useless, 262. Lecky, Mr., on the sense of duty, 97 ; on suicide, 117; on the practice of celibacy, 119; his view of the crimes of savages, 119 ; on the gradual rise of morality, 125. Leconte, J. L., on the stridulant organ in the Coprini and Dynastini, 303. Lee, H., on the numerical proportion of the sexes in the trout, 249. Leg, calf of the, artificially modified, 574. Legitimate and illegitimate children, proportion cf the sexes in, 244. Legs, variation of the length of the, in man, 26 ; proportions of, in sol- diers and sailors, 32 ; front, atro- phied in some male butterflies, 277 ; peculiarities of, in male insects, 277. Leguay, on the occurrence of the supra-condyloid foramen in the humerus of man, 22. “ Lek ” of the black-cock and caper- cailzie, 405. Lemoine, Albert, on the origin of lan- guage, 87. Lemur macaco, sexual difference of colour in, 537. Lemurida:, 152 ; ears of the, 15 ; variability of the muscles in the, 41 ; position and derivation of the, 157 ; their origin, 165. Lemurs, uterus in the, 38. Lenguas, disfigurement of the ears of the, 575. Leopards, black, 539. Lepidoptera, 307 ; numerical propor- tions of the sexes in the, 250 ; colouring of, 308 ; ocellated spots of, 427. Lepidosiren, 159, 165. Leptalides, mimicry of, 325. Leptorhynchus angustatus, pngnacity of male, 299. Leptura testacea, difference of colour in the sexes of. 294. Leroy, on the wariness of young foxes in hunting-districts, 80; on the desertion of their young by swal- lows, 108. Leslie, D., marriage customs of Kaflirs, 598. Lesse, valley of the, 22. Lesson, on the birds of paradise, 219, 403 ; on the sea-elephant, 528. Lessona, M., observations on Serraniis, 162. Lcthrus cephalotes, pugnacity of the males of, 297, 300. Leuckart, R., on the vesicula prosta- tica, 24 ; on the influence of the age of parents on the sex of off- spring, 245. Levator claviculai muscle, 42. Libellula depressa, colour of the male, 290. Libellulido!, relative size of the eexcf UCE. INDEX. LUBBOCK. 66 1 of, 279 ; difierence in the sexes of, 290. Lice cf domestic animals and man, 169. Licentiousness, a check upon popula- tion, 46 ; prevalence of, among savages, 119. Lichtenstein, on Chera progne, 419. Life, inheritance at corresponding periods of, 228, 232. Light, effects on complexion, 32 ; in- fluence of, upon the colours of shells, 263. Lilford, Lord, the ruff attracted by bright objects, 413. Limosa lapponica, 478. Linaria, 462. montana, 248. Lindsay, Dr. W. L., diseases commu- nicated from animals to man, 7 ; madness in animals, 79 ; the dog considers his master his God, 96. Linnaeus, views of, as to the position of man, 149. Linnet, numerical proportion of the sexes in the, 248 ; crimson fore- head and breast of the, 394 ; court- ship of the, 401. Lion, polygamous, 218 ; mane of the, defensive, 521 ; roaring of the, 526. Lions, stripes of young, 464. Lips, piercing of the, by savages, 575. Lithobius, prehensile appendages of the female, 274. Zithosia, coloration in, 314. Littorina littorea, 262. Livingstone, Dr., manner of sitting of gorilla, 151 ; on the influence of dampness and dryness on the colour of the skin, 193 ; on the liability of negroe." to tropical fevers after residence in a cold climate, 194; on the spui’-winged goose, 364 ; on weaver-birds, 376 ; on an African night-jar, 384, 403 ; on the battle- scars of South .African male mam- mals, 500 ; on the removal of the upper incisors by the Batokas, 575; on the perforation of the upper lip by the Makalolo, 576 ; on the Banyai, 579. Livonia, numerical proportion of male and female births in, 215, 243. Lizards, relative size of the sexes of, 354 ; gular pouches of, 354. Lloyd, L., on the polygamy of the capercailzie and bustard, 219 ; on the numerical proportion of the sexes in the capercailzie and black- cock, 248 ; on the salmon, 333 ; on the colours of the sea-scorpion, 337 ; on the pugnacity of male grouse, 364 ; on the capercailzie and black-cock, 366, 370; on the call of the capercailzie, .375 ; on assemblages of grouse and snipes, 405 ; on the pairing of a shield- drake with a common duck, 414 ; on the battles of seals, 500 ; on the elk, 507. Lobivanellus, wing-spurs in, 366. Local influences, effect of, upon sta- ture, 31. Lockwood, Mr., on the development of Hippocampus, 163. , Rev. S., musical mouse, 568. Locust, hi-ight-coloured, rejected by lizards and birds, 289. , migi-atory, 283; selection by female, 283. Locusts, proportion of sexes in, 254 ; stridulation of, 284. Locustidae, stridulation of the, 282, 284 ; descent of the, 285. Longicorn beetles, difference of the sexes of, in colour, 294 ; stridula- tion of, 303. Lonsdale, Mr., on an example of per soual attachment in Helix pomatia, 263. Lophobranchii, marsupial receptacles of the males, 346. Lophophorus, habits of, 420. Zophorina atra, sexual difference in coloration of, 491. Lophornis ornatus, 387 Loi'd, J. K., on Salmo lyoaodon, 333. Lory, King, 457 ; immature plumage of the, 467. Love-antics and dances of birds, 380. Lowne, B. T., on Musca vomitoria, 54, 280. Loxia, characters of young of, 464. Lubbock, Sir J., on the antiquity of man, 2 ; on the origin of man, 3 ; on the mental capacity of savages, 65 ; on the origin of implements, 82 ; on the simplification of lan- guages, 92 ; on the absence of the idea of God among certain races ot 662 LUCANID^. INDEX.. MA.CGILLIVKAY. men, 94; on the origin of the belief in spiritual agencies, 95, on superstitions, 96 ; on the sense of duty, 97 ; on the practice of burying the old and sick among the Fijians, 102 ; on the im- morality of savages, 119 ; on Mr. Wallace’s claim to the origination of the idea of natural selection, 49 ; on the absence of remorse among savages, 131 ; on the former barbarism of civilised nations, 143 ; on improvements in the arts among savages, 144 ; on resemblances of the mental characters in different races of men, 178 ; on the arts practised by savages, 179 ; on the power of counting in primeval man, 180; on the prehensile organs of the male Labidocera Darwinii, 266 ; on Chloeon, 274 ; on Smynthurus luteus, 279 ; finding of new mates by jays, 407 ; on strife for women among the North American Indians, 561 ; on music, 570; on the orna- mental practices of savages, 574 ; on the estimation of the beard among the Anglo-Saxons, 581 ; on artificial deformation of the skull, 583 ; on “ communal mar- riages,” 587, 588; on exogamy, 589, 592 ; on the Veddahs, 591 ; on polyandry, 593. Lucanidse, variability of the mandibles in the male, 300. Lucanus, large size of males of, 278. cervus, numerical proportion of sexes of, 253 ; weapons of the male, 299. elaphus, use of mandibles of, 300 ; large jaws of male, 275. Lucas, Prosper, on pigeons, 418 ; on sexual preference in horses and bulls, 525. Lunar periods, 8, 164. Lund, Dr., on skulls found in Bra- zilian caves, 168. Lungs, enlargement of, in the Qui- chua and Aymara Indians, 34; a modified swim-bladder, 161 ; different capacity of in races of man, 167. Luminosity in insects, 277. Luschka, Prof., on the termination of the coccyx, 23. Luxui’y, expectation of life uniu- fiuenced by, 136. LyccBna, sexual differences of colour- ing in species of, 310. Lyell, Sir C., on the antiquity o£ man, 2 ; on the origin of man, 3 ; on the parallelism of the de- velopment of species and languages, 90; on the extinction of lan- guages, 90 ; on the Inquisition, 141 ; on the fossil remains of ver- tebrata, 157 ; on the fertility of mulattoes, 171. Lynx, Canadian, throat-ruff of the, 521. Lyre-bird, assemblies of, 406. H. Macoxus, ears of, 15 ; convoluted body in the extremity of the tail of, 23 ; variability of the tail in species of, 58 ; whiskers of species of, 531. brunneus, 59. cynomolgus, superciliaiy’ ridge of, 558 ; beard and whiskers of, becoming white with age, 559. ecaiidatus, 60. lasiotus, facial spots of, 550. • radiatus, 151. rhesus, sexual difference in the colour of, 539, 550. Macalister, Prof., on variations of the palmaris accessorius muscle, 27 ; on muscular abnormalities in man, 42, 43 ; on the greater varia- bility of the muscles in men than in women, 223. Macaws, Mr. Buxton’s observations on, 102 ; screams of, 375. McCann, J., on mental individuality, 84. McClelland, J., on the Indian Cypri- nidse, 343. Macculloch, CoL, on an Indian vil- lage without any female children, 592. , Dr., on tertian ague in a dog, 8. Macgillivray, W., on the vocal organs of birds, 90; on the Egyptian goose, 365 ; on the habits of wood- pec’Kers, 376 ; on the habits of the snipe, 377; on the whilethroat, 381 ; on the moulting of the snipes MACHETES. IKDEX. MAMMALIA. 663 391 ; on the moulting of the Anatidae, 393 ; on the finding of new mates by magpies, 407 ; on the pairing of a blackbird and thrush, 414 ; on pied ravens, 424 ; on the guillemots, 424 ; on the colours of the tits, 458 j on the immature plumage of birds, 466 et seq. Machetes, sexes and young of, 485 ; pugnax, supposed to be polyga- mous, 219 ; numerical proportion of the sexes in, 248 ; pugnacity of the male, 360 ; double moult in, 390. McIntosh, Dr. colours of the Nemer- tians, 265. McKennan, marriage customs of Koraks, 598. Mackintosh, on the moral sense, 97. MacLachlan, R., on Apatania mulie- bris and Boreus hyemalis, 254; on the anal appendages of male insects, 275 ; on the pairing of dragon-flies, 279 ; on dragon-flies, 290, 291 ; on dimorphism in Agrion, 291 ; on the want of pug- nacity in male dragon-flies, 291 ; ^ colour of ghost-moth in the Shet- land Islands, 316. McLennan, Mr., on infanticide, 46, 591 ; on the origin of the belief in spiritual' agencies, 94; on the pre- valence of licentiousness among savages, 119, 588; on the primi- tive barbarism of civilised nations, 143 ; on traces of the custom of the forcible capture of wives, 144, 592 ; on polyandry, 593. Macnamara, Mr., susceptibility of Andaman islanders and Nepalese to change, 188. McNeill, Mr., on the use of the ant- lers of deer, 510 ; on the Scotch deerhound, 516; on the long hairs on the throat of the stag, 522 ; on the bellowing of stags, 526. Macropus, courtship of, 341. Alacrorhinus proboscideus, structure of the nose of, 528. Magpie, power of speech of, 90 ; nuptial assemblies of, 406 ; new mates found by, 407 ; stealing bright objects, 413 ; young of the, 481 ; coloration of the, 493. Magpies, vocal organs of the, 370 Maillard, M., on the proportion of the sexes in a species of Papilio from Bourbon, 250. Maine, Sir Henry, on the absorption of one tribe by another, 128; a desire for improvement not general, 132. Major, Dr. C. Forsyth, on fossil Italian apes, 155; skull of Bos etruscus, 505 ; tusks of miocene pigs, 521. Makalolo, perforation of the upper lip by the, 57 6. Malar bone, abnormal division of, in man, 39. Malay, Archipelago, marriage-cus- toms of the savages of the, 598. Malays, line of separation between the Papuans and the, 169 ; general beardlessness of the, 560 ; staining of the teeth among, 574 ; aversion of some, to hairs on the face, 581. and Papuans, contrasted cha- racters of, 168. Male animals, struggles of, for the possession of the females, 212, 213 ; eagerness of, in courtship, 221, 222 ; generally more modified than female, 221, 223 ; diflhr in the, same way from females and young, 232. characters, developed in females, 227 ; transfer of, to female birds, 471. , sedentary, of a hymenopterous parasite, 221. Malefactors, 137. Males, presence of rudimentary female organs in, 162. • and females, comparative num- bers of, 213, 215 ; comparative mortality of, while young, 216. Malherbe, on the woodpeckers, 458. Mallotus peronii, 331. villosus, 331. Malthus, T., on the rate of increase of population, 44, 45. 46. Maluridee, nidification of the, 454. Malurus, young of, 485. Mammae, 208 ; rudimentary, in male mammals, 11, 23, 161, 162, 163 ; supernumerary, in women, 36 ; of male human subject, 37. Mammalia, Prof. Owen’s classification of, 148 ; genealogy of the, 158. 664 MAMMALS. INDEX. MAYHEW. iiammals, recent and tertiary, com- parison of cranial capacity of, 55 ; nipples of, 162 ; pursuit of female, by the males, 221 ; secondary sexual characters of, 500 ; weapons of, 501 ; relative size of the sexes of, 515 ; parallelism of, with birds in secondary sexual characters, 541 ; voices of, used especially during the breeding season, 567. Man, variability of, 26 ; erroneously regarded as more domesticated than other animals, 28 ; migrations of, 47; wide distribution of, 48 ; causes of the nakedness of, 57 ; supposed physical inferiority of, 64 ; a mem- ber of the Catarrhine group, 155 ; early progenitors of, 160; transition from ape indefinite, 180; numerical proportions of the sexes in, 215 ; difference between the sexes, 223 ; proportion of sexes amongst the illegitimate, 244; different com- plexion of male and female negroes, 556 ; secondary sexual characters of, 556 ; primeval condition of, 594. Mandans, correlation of colour and texture of hair in the, 197. Mandible, left, enlarged in the male of Taphroderes distortus, 276. Mandibles, use of the, in AmmopMla, 275 ; large, of Corydalis comutus, 27 5 ; large, of male Lucanus ela- phus, 275. Mandrill, number of caudal vertebrae in the, 58 ; colours of the male, 538, 541, 550. Mantegazza, Prof., on last molar teeth of man, 20 ; bright colours in male animals, 224 ; on the orna- ments of savages 573 et seq. ; on the beardlessness of the New Zea- landers, 581 ; on the exaggeration of natural characters by man, 582. Mantell, W., on the engrossment of pretty girls by the New Zealand chiefs, 595. Mantis, pugnacity of species of, 289. Maories, mortality of, 184 ; infanti- cide and proportion of sexes, 256 ; distaste for hairiness amongst men, 581. Marcus Aurelius, on the origin of the moral sense, 98 ; on the influence of habitual thoughts, 123. Mareca penelope, 414. Marks, retained throughout groups of birds, 427. Marriage, restraints upon, among sa- vages, 46; influence of, upon morals, 119; influence of, on mortality, 139 ; development of, 590. Marriages, early, 138, 139 ; com- munal, 587, 589. Marshall, Dr. W., protuberances on birds’ heads, 235, 383 ; on the moulting of birds, 393 ; advantage to older birds of paradise, 485. , Col., interbreeding amongst Todas, 189 ; infanticide and pro- portion of sexes with Todas, 255 ; choice of husbands amongst Todas, 593. , Mr., on the brain of a Bush- woman, 167. Marsupials, 157 ; development of the nictitating membrane in, 17 ; uterus of, 39 ; possession of nipples by, 162; their origin from Monotre- mata, 165 ; abdominal sacks of, 208 ; relative size of the sexes of, 515 ; colours of, 533. Marsupium, rudimentary, in male marsupials, 161. Martin, W. C. L., on alarm manifested by an orang at the sight of a turtle, 72 ; on the hair in Hyldbates, 152 ; on a female American deer, 514 ; on the voice of Hylobates agilis, 527 ; on Semnopithecus netnosus, 552. . on the beards of the inhabitants of St. Kilda, 560. Martins deserting their young, 108. , C., on death caused by inflam- mation of the vermiform appen- dage, 21. Mastoid processes in man and apes, 53. Maudsley, Dr., on the influence of the sense of smell in man, 18; on idiots smelling their food, 36 ; on Laura Bridgman, 88 ; on the de- velopment of the vocal organs, 89 ; moral sense failing in incipient madness, 124 ; change of mental faculties at puberty in man, 565. Mayers, W. F., on the domestication of the goldfish in China, 343. Mayhew, E., on the affection between individuals of different sexes in the dug, 523. MAYNARD. INDEX. MOGGRIDGE. 665 Maynard, C. J-, on the sexes of Chry- semi/s picta, 351. Meckel, on :orrelate4 variation of the muscles of the arm and leg, 44. Medicines, effect produced by, the same in man and in monkeys, 7. Meduses, bright colours of some, 260. Megalithic structures, prevalence of, 179. Megapicus validus, sexual difference of colour in, 458. Megasoma, large size of males of, 279. Meigs, Dr. A., on variation in the skulls of the natives of America, 26. Meinecke, on the numerical propor- tion of the sexes in butterflies, 250. Melanesians, decrease of, 185. Meldola, Mr., colours and marriage flight of Colias and Pieris, 319. Meliphagidae, Australian, nidification of, 454. Melita, secondary sexual characters of, 268. Meloe, difference of colour in the sexes of a species of, 294. Memory, manifestations of, in ani- mals, 74. Memnon, young, 168. Mental characters, difference of, in different races of men, 167. faculties, diversity of, in the same race of men, 26 ; inheritance of, 27 ; variation of, in the same species, 27, 66 ; similarity of the in different races of man, 178 ; of birds, 410. powers, difference of, in the two sexes in man, 563. Menura Alberti, 406 ; song of, 371. superba, 406 ; long tails of both sexes of, 451. Merganser, trachea of the male, 374. serrator, male plumage of, 393. Mergus cucuUatus, speculum of, 236. merganser, young of, 467. Metallura, splendid tail-feathers of, 443. Methoca ichneumonides, large male of, 279. Meves, M., on the drumming of the snipe, 377. Mexicans, civilisation of the, not foreign, 145. Meyer, on a convoluted body at the extremity of the tail in a Macacus and a cat, 23. , Dr. A., on the copulation of Phryganidaj of distinct species, 275. , Prof. L., on development of helix of ear, 15, 16 ; men’s ears more variable than women’s, 224 ; antennae serving as ears, 280. Migrations of man, effects of, 47. Migratory instinct of birds, 105 ; vanquishing the maternal, 107, 113. Mill, J. S., on the origin of the moral sense, 98 ; on the “ greatest hap- piness principle,” 120 ; on the dif- ference of the mental powers in the sexes of man, 564. Millipedes, 274. Milne-Edwards, H., on the use of the enlarged chelae of the male Qelasi- mus, 267. Milvago leucurus, sexes and young of, 479. Mimicry, 323. Mimus polyglottus, 411. Mind, difference of, in man and the highest animals, 126 ; similarity of the, in different races, 178. Minnow, proportion of the sexes in the, 249. Mirror, larks attracted by, 413. Mitchell, Dr., interbreeding in the Hebrides, 189. Mitford, selection of children in Sparta, 29. Mivart, St. George, on the reduction of organs, 12 ; on the ears of the lemuroidea, 15; on variability of the muscles in lemuroidea, 41, 48 ; on the caudal vertebras of monkeys, 58 ; on the classification of the primates, 153 ; on the oraug and on man, 154 ; on differences in the lemuroidea, 155 ; on the crest of the male newt, 348. Mobius, Prof., on reasoning powers in a pike, 75. Mocking-thrush, partial migration of, 411 ; young of the, 487. Modifications, unserviceable, 62. Moggridge, J. T., on habits of spiders, 69 ; on habits of ants, 147. 666 MOLES. INDEX. MOTAOILLiE. Moles, numerical proportion of the sexes in, 247 ; battles of male, 500. Mollienesia potenensis, sexual dififer- ence in, 337. Mollusca, beautiful colours and shapes of, 263 ; absence of secondary sexual characters in the, 262. Molluscoida, 159, 262. Mojiacanthus scopas and M, Peronii, 331. ttongolians, perfection of the senses in, 34. Monkey, protecting his keeper from a baboon, 103, 110; bonnet-, 151; rhesus-, sexual difference in colour of the, 539, 550 ; moustache-, colours of the, 537. Monkeys, liability of, to the same diseases as man, 7 ; male, recog- nition of women by, 8 ; diversity of the mental faculties in, 27 ; breaking hard fruits with stones, 50 ; hands of the, 50, 51 ; basal caudal vertebrae of, imbedded in the body, 59 ; revenge taken by, 69 ; maternal affection in, 70 ; varia- bility of the faculty of attention in, 74 ; American, manifestation of reason in, 77 ; using stones and sticks, 81 ; imitative faculties of, 87 ; signal-cries of, 87 ; mutual kindnesses of, 101 ; sentinels posted by, 101 ; human characters of, 150; American, direction of the hair on the arms of some, 151 ; gradation of species of, 175; beai’ds of, 531 ; ornamental characters of, 549 ; analogy of sexual differences of, with those of man, 558; dif- ferent degrees of difference in the sexes of, 561 ; expression of emo- tions by, 572 ; generally mono- gamous habits of, 590 ; polygamous habits of some, 590 ; naked surfaces of, 600. Monogamy, not primitive, 144. Monogenists, 176. Mononychus pseudacori, stridulation of, 305. Monotremata, 157 ; development of the nicitating membrane in, 17 ; lactiferous glands of, 162 ; connect- ing mammals with reptiles, 165. Monstrosities, analogous, in man and lower animals, 30 ; caused by arrest of development, 35 ; correlation of, 44 ; transmission of, 173. Montagu, G., on the habits of the black and red grouse, 219 ; on the pugnacity of the ruff, 361 ; on ttie singing of birds, 368 ; on the double moult of the male pintail, 393. Monteiro, Mr., on Bucorax abyssi- nicus, 383. Montes de Oca, M., on the pugnacity of male Humming-birds, 360. Monticola cyanea, 456. Monuments, as traces of extinct tribes, 181. Moose, battles of, 501 ; horns of the, an incumbrance, 515. Moral and instinctive impulses, alli- ance of. 111. faculties, their influence on natural selection in man, 127. rules, distinction between the higher and lower, 122. sense, so-called, derived from the social instincts, 120, 121; origin of the, 124. tendencies, inheritance of, 124. Morality, supposed to be founded in selfishness, 120 ; test of, the general welfare of the community, 121 ; gradual rise of, 125 ; influence of a high standard of, 132. Morgan, L. H., on the beaver, 67 ; on the reasoning powers of the beaver, 75 ; on the forcible capture of wives, 144 ; on the castoreum of the beaver, 529 ; marriage unknown in primeval times, 588 ; on poly- andry, 593. Morley. J., on the appreciation of praise and fear of blame, 146. Morris, F. 0., on hawks feeding an orphan nestling, 409. Morse, Dr., colours of mollusca, 264. Morselli, E., division of the malar bone, 39. Mortality, comparative, of females and males, 216, 243. Morton, on the number of species of man, 174. Moschkau, Dr. A., on a speaking starling, 85. Moschus TTioschifcrus, odoriferons or- gans of, 529. Motacillce, Indian, young of, 468. MOTHS. INDEX. MUSIC. 667 Moths, 313; absence of mouth in some males, 208 ; apterous female, 208 ; male, prehensile use of the tarsi by, 209 ; male, attracted by females, 252; colox’ation of, 315; sexual difiFerences of colour in, 316. Motmot, inheritauce of mutilation of tail feathers, 60, 603 ; racket- shaped feathers in the tail of a, 384. Moult, double, 463; double annual, in birds, 390. Moulting of birds, 484. Moults, partial, 392, Mouse, song of, 568. hloustache-monkcy, colours of the, 537, 552. Moustaches, in monkeys, 150. Mud-turtle, long claws of the male, 350. ilulattoes, persistent fertility of, 171 ; immunity of, from yellow fever, 193. Mule, sterility and strong vitality of the, 171. Mules, rational, 78. Muller, Ferd., on the Mexicans and Peruvians, 145. , Fritz, on astomatous males of Tanais, 208 ; on the disappearance of spots and stripes in adult mam- mals, 547 ; on the proportions of the sexes in some Crustacea, 255 ; on secondary sexual characters in various Crustaceans, 265 et seq. ; musical contest between male Ci- cada;, 282 ; mode of holding wings in Castnia, 315 ; on birds shewing a preference for certain colours, 317 ; on the sexual maturity of young amphipod Crustacea, 485. , Hermann, emergence of bees from pupa, 214; pollen-gathering of bees, 228 ; proportion of sexes in bees, 254 ; courting of Eristalis, 280 ; colour and sexual selection with bees, 292. , J., on the nictitating membrane and semilunar fold, 17. , Max, on the origin of language, 87 ; language implies power of general conception, 88 ; struggle for life among the words, &c., of languages, 91. , S., on the banteng, 536 ; on the colours of Semnopithecus chry- somelas, 537. Muntjac-deer, weapons of the, 514. Murie, J., on the reduction of organs, 12 ; on the ears of the Lemuroidea, 15 ; on variability of the muscles in the Lemuroidea, 41, 48 ; basal caudal vertebra: of Macacus hrun- neus imbedded in the body, 59 ; on the manner of sitting in short- tailed apes, 59 ; on differences in the Lemuroidea, 155 ; on the throat-pouch of the male bustard, 373; on the mane of Otaria juhata, 521 ; on the sub-orbital pits of Kuminants, 529 ; on the colours of the sexes in Otaria nigrescens, 535. Murray, A., on the Pediculi of dif- ferent races of men, 169. T. A., on the fertility of Austra- lian women with white men, 170. Mus coninga, 80. minutus, sexual difference in the colour of, 534. Musca vomitoria, 54. Muscicapa grisola, 455. luctuosa, 455. ruticilla, breeding in immature plumage, 484. Muscle, ischio-pubic, 41. Muscles, rudimentary, occurrence of, in man, 12 ; variability of the, 26 ; effects of use and disuse upon, 32 ; animal-like abnormalities of, in man, 41 ; correlated variation of, in the arm and leg, 44 ; variability of, in the hands and feet, 48 ; of the jaws, influence of, on the phy- siognomy of the Apes, 54 ; habitual spasms of, causing modifications of the facial bones, 55 ; of the early progenitors of man, 160 ; greater variability of the, in men than in women, 223. Musculns sternalis. Prof. Turner on the, 13. Music, 178 ; of birds, 368 ; discord- ant, love of savages for, 380 ; rea- son of power of perception of notes in animals, 568 ; power of distin- guishing notes, 569 ; its connection with primeval speech, 570; differ- ent appreciation of, by diffei-ent peoples, 570; origin of, 569, 573 effects of, 571. 668 MUSICAL. INDEX. NEW ZEALAND. Musical cadences, perception of, by animals, 569 ; powers of man, 566 et seq. Musk-deer, canine teeth of male, 502, 513, 514 ; male, odiferous organs of the, 529 ; winter change of the, 542. Musk-duck, Australian, 359 ; large size of male, 362 ; of Guiana, pug- nacity of the male, 362. Musk-ox, horns of, 505. Musk-rat, protective resemblance of the, to a clod of earth, 542. MusophagcB, colours and nidification of the, 455 ; both sexes of, equally brilliant, 460. Mussels opened by monkeys, 50. Mmtela, winter change of two species of, 542. Musters, Capt., on Rhea JDarwinii, 479 ; marriages amongst Patago- nians, 598. Mutilations, healing of, 8 ; inheri- tance of, 60. Mutilla europ w , j. »\ ■■ r. ~- t ..:V ■ • H 1 1 ■ 1 S '- ■ ®Tfia j --L. ■ • ; J- ‘ ■ ^