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HT sieteies Sahay apererste spirits Tare ath +74 steseteisicienstess siisatitteserete tree presova ese the 4 poet seaeed| brerecress 2h 3b eee es seer TE) Ts : ste s5t prereyes see senge o4 iescteeeret tae USS SSUBE ieeciee i} ao tot i dpsed, Hip if sera tshseet ststae sesh ; e oe wo se o 3 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, etc. — The bearing of these three great classes of facts on the origin of man, CHAPTER IL On THE MANNER OF DEVELOPMENT OF MAN FROM SOME LOWER F ORM, ° ° ° ° > ° ° > e o ° Variability of body and mind in man—Inheritance—Causes of varias bility—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. CHAPTER III. CoMPARISON OF THE MENTAL POWERS OF MAN AND THE LOWER ANIMALS, . : ° : ° ° ° ° ° The difference in mental power between the highest ape and the lowest savage, immense—Certain instincts in common—The emotions Curiosity —- Imitation — Attention — Memory — Imagination< 3 | 12 CONTENTS, PAGB Reason—Progressive improvement—Tools and weapons used pe animals-—Abstraction, self-consciousness—.-Language—Sense beauty— Belief in God, spiritual agencies, superstitions, CHAPTER IV. COMPARISON OF THE MENTAL POWERS OF MAN AND THE LOWER ANIMALS—continued, a e p P " . 112 The moral sense-—-Fundamental proposition--The qualities of social animals—Origin of sociability-—-Struggle between opposed in- stincts—Man a social animal—The more enduring social instincts conquer other less persistent instincts—The social virtues alone regarded by savages—The self-regarding virtues 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. CHAPTER V, ON THE DEVELOPMENT OF THE INTELLECTUAL AND MORAL FACUL- TIES DURING PRIMEVAL AND CIVILIZED TIMES, . . . 148 Advancement of the intellectual powers through natural selection importance of imitation—Social and moral faculties—Their de- velc ment within the limits of the same tribe—Natural selection as affecting civilized nations—Evidence that civilized nations were once barbarous. CHAPTER VI. On THE AFFINITIES AND GENEALOGY OF MAN, , . oe, Position of man in the animal series--The natural system genealogical — Adaptive characters of slight value—-Various small points of re-- semblance between man and the quadrumana—Rank of man in the natural system—Birthplace and astiquity of man—Absence of fossil connecting-links— Lower stages in the genealogy of man, as inferred, firstly from his affinities and secondly from his structure—Early androgynous condition of the Vertebrata— Conclusion. CHAPTER VIL On TSE Races oF MAN, 2s ps Fae tag es ign The nature and value of specific characters—Application to the races of man—Arguments in favor of, and opposed to, ranking the soe called races of man as distinct species—-Sub-species—Monogenists and polygenists—Convergence of character—Numerous points of resemblance in body and mind between the most distinct races of rm.1—The state of man when he first spread over the earth Each race not descended from a single pair—The extinction of CONT. ENTS. *eces~-The formation of races—The effects of crossing—Slight influence «f the direct action of the conditions of life—Siight oe @o imducace of natural selection—Sexual seiection. PART II. SEXUAL SELECTION. CHAPTER VIIL PRINCIPLES OF SEXUAL SELECTION, ‘ A <é ; Pi P 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 watural selection—Inheritance at corresponding periods of life, at torresponding seasons of the year, and as limited by sex—Relae tions 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 through- out the animal kingdom—The proportion of the sexes in relation to natural selection, CHAPTER IX. SECONDARY SEXUAL CHARACTERS IN THE LOWER CLASSES OF THE ANIMAL KINGDOM, . 4 : F J 6 : These characters absent in the lowest classes—Brilliant colors—Mol- Jusca—Annelids— Crustacea, secondary sexual characters strongly developed ; dimorphism ; color ; characters not acquired before maturity—Spiders, sexual colors of ; stridulation by the males— Myriapoda. CHAPTER X. SECONDARY SEXUAL CHARACTERS OF INSECTS, . P : . Diversified structures possessed by the males for seizing the females— Differences between the sexes, of which the meaning is not un- derstood—Difference in size between the sexes—Thysanura— Diptera—Hemiptera—Homoptera, musical powers possessed by the males alone—Orthoptera, musical iistruments of the males, much diversified in structure ; pugnacity ; colors—Neuroptera, sexual differences. in color—Hymenoptera, pugnacity and colors —Coleoptera, colors; furnished with great horns, apparently as an ornament ; battles ; stridulating organs generally common to both sexes. AS PAGE 278 293 14 CONTENTS CHAPTER XL {nsecTs, continued.—ORDER LEPIDOPTERA (BUTTERFLIES AND Morus), . © 9 ° ° & . . . os . sourtship of butterflies—Battles—Ticking noise—Colors common ta both sexes, or more brilliant in the males—Examples~ Not due to the direct action of the conditions of life—Colors adapted for protection—Colors of moths—Display—Perceptive powers of the Lepidoptera—Variability—Causes of the difference in color be- tween the males and females—Mimicry, female butterflies more brilliantly colored than the males—Bright colors of caterpillars— Summary and concluding remarks on the secondary sexual chare acters of insects—Birds and insects compared. CHAPTER XIL SECONDARY SEXUAL CHARACTERS OF FisHEs, AMPHIBIANS, AND REPTILES, ° 2 s c * e e e e FisHES: Courtship and battles of the males—Larger size of the females—Males, bright colors and ornamental appendages ; other strange characters—Colors and appendages acquired by the males during the breeding-season alone—Fishes with both sexes brill- iantly colored—Protective colors—The less conspicuous colors 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 color between the sexes—Vocal organs. REPTILES: Chelonians—Crocodiles— Snakes, colors in some cases protective—Lizards, battles of— Ornamental appendages—Strange differences in structure between the sexes—Colors—Sexual differences almost as great as with birds, CHAPTER XIIL SECONDARY SEXUAL CHARACTERS OF BIRDS, - ge Sexual differences—Law of battle—Special weapons—Vocal organs— Instrumental music—Love-antics and dances—Decorations, pere manent and seasonal—Double and single annual moults-~Display of ornaments by the males, CHAPTER XIV. Birps—continued, € e e > © 2 e a 2 . Choice exerted by the female—Length of courtship—Unpaired birds ~—Mental qualities and taste tor the beautiful—Preference or ane tipathy shown by the female for particular males—Variability of Paaa 325 - 358 428 CONTENTS. 15 PAGE birds—Variations sometimes abrupt—Laws of variation—Forma- tion of ocelli—Gradations of character—Case of Peacock, Argus pheasant, and Urosticte. CHAPTER XV. Birps—continued, e ° a . ° oO e ° 8 > £65 Discussion as to why the males alone of some species, and both sexes of others, are brightly colored—On sexually-limited inheritance, as applied to various structures and to brightly-colored plumage —Nidification in relation to color—Loss of nuptial plumage dur- ing the winter. CHAPTER XVI. Birps—concluded, ° e ° ° ° ° ° ° ° ° 485 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 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 coloring — Conspicuously-colored birds — Novelty appreciated — Summary of the four chapters on birds. CHAPTER XVII. SECONDARY SEXUAL CHARACTERS OF MAMMALS,., . . «@ §23 The law of battle—Special weapons, confined to the males—Cause of absence of weapons in the female—Weapons common to both sexes, yet primarily acquired by the male—Other uses of such weapons—Their high importance—Greater size of the male— Means of defence—On the preference shown by either sex in the pairing of quadrupeds. CHAPTER XVIII. SECONDARY SEXUAL CHARACTERS OF MAMMALS—continued, - 543 Woice— Remarkable sexual peculiarities in seals—Odor—Development of the hair—Color of the hair and skin—Anomalous case of the female being more ornamented than the male—Color and orna- ments due to sexual selection—Color acquired for the sake of protection—Color, though common to both sexes, often due to sexual selection—On the disappearance of spots and stripes in adult quadrupeds—On the colors and ornaments of the Quadru- mana—Summary. 16 CONTENTS, PART III. SEXUAL SELECTION IN RELATION TO MAN, AND CONCLUSION, CHAPTER XIX, . PAa® od >; f eg Differences between man and woman—Causes of such differences, and of certain characters common to both sexes—Law of battle—Dif- ferences in mental powers, and voice—On the influence of beauty in determining the marriages of mankind—Attention paid by sav- ages to ornaments—Their ideas of beauty in woman—The ten- dency to exaggerate each natural peculiarity, SECONDARY SEXUAL CHARACTERS OF MAN, CHAPTER XX, SECONDARY SEXUAL CHARACTERS OF MAN—continued,. .« .« 608 On 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 civilized and savage nations— Conditions favorable 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—Color of the skin—Summary, CHAPTER XXL GENERAL SUMMARY AND CONCLUSION, . wbhoas = lo wine 630 Main conclusion that man is descended from some lower form— Man- ner of development—Genealogy of man—Intellectual and moral faculties—-Sexual selection—Concluding remarks. THE DESCENT OF MAN; AND SELECTION IN RELATION 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 publish, as I thought that I should thus only add to the prejudices against my views. It seemed to me sufficient to indicate, in the first edition of my ‘‘ Origin of Species,’’ that by this work ‘‘light would be thrown on the origin of man and his history ;’’ and this implies that man must be included with other organic beings in any general con- clusion respecting his manner of appearance on this earth. Now the case wears a wholly different aspect. When a naturalist like Carl Vogt ventures to say in his address as President of the National Institution of Geneva (1869), ‘* personne, en Europe au moins, n’ose plus soutenir la création indépendante et de toutes piéces, des espéces,’’ it is manifest that at least a large number of naturalists must admit that species are the modified descendants of other species ; and this especially holds good with the younger and rising naturalists. The greater number accept the agency of natural selection; though some urge, whether with justice the future must decide, that I have greatly overrated its importance. Of the older and hono‘ed chiefs in atural science, many unfortunately are still opposed to evolu- tion in every form, 13 INTRODUCTION. In consequence of the views now adopted by most naturalists, and which will ultimately, as in every other case, be followed by others who are not scientific, I have been led to put together my notes, so as to see how far the general conclusions arrived at in my former works were applicable to man. ‘This seemed all the more desirable, as I had never deliberately applied these views to a species taken singly. When we confine our attention to any one form, we are deprived of the weighty arguments derived from the nature of the affinities which connect to- gether whole groups of organisms—-their geographical distribu- tion in past and present times, and their geological succession. The homological structure, embryological development, and rudimentary organs of a species remain to be considered, whether it be man or any other animal to which our attention may be directed; but these great classes of facts afford, as it appears to me, ample and conclusive evidence in favor of the principle of gradual evolution. The strong support derived from the other arguments should, however, always be kept be- fore 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 labors of a host of emi- nent men, beginning with M. Boucher de Perthes; and this is the indispensable basis for understanding his origin. I shall, therefore, take this conclusion for granted, and may refer my readers to the admirable treatises of Sir Charles Lyell, Sir John Lubbock, and others. Nor shall I have occasion te do more than to allude to the amount of difference between man and the anthropomorphous apes ; for Prof. Huxley, in the opinion of most competent judges, has conclusively shown that in every visible character man differs less from the higher apes than these do from the lower members of the same arder 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 draught, appeared to me interesting, I thought that they might interest others. It has often and confidently been INTRODUCT/ON. 19 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-descendant with other species of some ancient, lower, and extinct form, is not in any degree new. Lamarck long ago came to this con-- clusion, which has lately been maintained by several eminent naturalists and philosophers ; for instance, by Wallace, Huxley, Lyell, Vogt, Lubbock, Biichner, Rolle, etc.,! and especially by Hackel. This last naturalist, besides his great work, ‘‘ Generelle Morphologie ’’ (1866), has recently (1868, with a second edit. in 5870), published his ‘‘ Natiirliche Schépfungsgeschichte,’’ in which he fully discusses the genealogy of man. If this work had appeared before my essay had been written, I should prob- ably never have completed it. Almost all the conclusions at which I have arrived I find confirmed by this naturalist, whose knowiedge on many points is much fuller than mine. Where- ever I have added any fact or view from Prof. Hackei’s writ- ings, I give his authority in the text; other statemencs 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. During many years it has seemed to me highly probable that sexual selection has played an important part in differentiating the races of man; but in my ‘‘ Origin of Species’’ (first edi- tion, 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 subiect in full detail.2 Con- sequently the second part of the present work, treating of sexual selection, has extended 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 ithe lower 1 As the works of the first-named authors are so well known, I need not give the titles; but as those of the latter are less well known in England, I[ will give them: ‘‘ Sechs Vorlesungen itiber die Darwin’ sche Theorie: ” zweite Auflage, 1868, von Dr. L. Biichner ; translated into French under the title ‘“‘Con- a férences sur la Théorie Darwinienne,’’ 1869. ** Der Mensch, im Lichte der Darwin’sche Lehre,” 1865, von Dr. F. Rolle. I will not attempt to give references to all the authors who have taken the same side of the ques- tion. Thus G. Canestrini has published €* Annvario della Soc. d. Nat..”” Madena. 1867, p. 81) a very curious paper on rudi- mentary characters, as bearing on the origin of man. Another work has (:869) been pub- lished by Dr. Francesco Barrago, bearing in Italian the title of “‘ Man, made in the image - of God, was also made in the image of the 2 Prof. Hickel was the only author who, at the time when this work first appeared, had discussed the subject of sexual selec- tion, and had seen its full importance, since the publication of the “ Origin ;” and this he did in a very able manner in bis varioag warks, 2c INTRODUCTION, animals. My attention was called to this subject many years ago by Sir Charles Bell’s admirable work. This illustrious anatomist maintains that man is endowed with certain muscles solely for the sake of expressing his emotions. As this view is obviously opposed to the belief that man is descended from some other and lower form, it was necessary for me to consider it. I likewise wished to ascertain how far the emotions are ex- pressed in the same manner by the different races of man. But owing to the length of the present work, I have thought it better to reserve my essay for separate publication. PART f THE DESCENT OR ORIGIN OF MAN. - CHAPTER I. THE FVIDENCE OF THE DESCENT OF MAN FROM SOME LOWER FORM. Wature of the evidence bearing on the origin of man—Homologous structures in man and the lower animals—Miscellaneous points of correspondence—Develepment—Rudimentary structures, muscles, sense-organs, hair, bones, reproductive organs, etc.—The bearing of these three great classes of facts on the origin of man. HE who wishes to decide whether man is the modified descend- ax.t of some pre-existing form would probably first inquire whether man varies. however slightly, in bodily structure and in mental faculties ; and if so, whether the variations are trans- mitted to his offspring in accordance with the laws which prevail with the lower animals. Again, are the variations the result, as far as our ignorance permits us to judge, of the same general causes, and are they governed by the same general laws, as in the case of other organisms ; for instance, by correlation, the inherited effects of use and disuse, etc.? Is man subject to similar malconformations, the result of arrested development, of reduplication of parts, etc., and does he display in any of his anomalies reversion to some former and ancient type of structure? It might also naturally be inquired 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, whea @2 THE DESCENT OF MAN. [PART L crossed, do they react on each other in the first and succeeding generations ? And so with many other points. The inquirer would next come to the important point ‘whether man tends to increase at so rapid a rate as to lead to occasional severe struggles for existence ; and consequently to beneficial variations, whether in body or mind, being preserved, and injurious ones eliminated. Do the races or species of men, whichever term may be applied, encroach on and replace one another, so that some finally become extinct? We shall see that all these questions, as indeed is obvious in respect to most of them, must be answered in the affirmative, in the same manner as with the lower animals. But the several considerations just referred to may be conveniently deferred for a time: and we will first see how far the bodily structure of man 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 mame 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 shown 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 their brains perfectly agree ; nor could perfect agreement be expected, for otherwise their mental powers would have been the same. Vulpian ’ remarks: ‘¢Les différences réelles qui existent entre l’encéphale de Vhomme et celui des singes supérieurs, sont bien minimes. I ne faut pas se faire d’illusions 4 cet égard. L’ homme est bien plus prés des singes anthropomorphes par les caractéres anato- miques de son cerveau que ceux-ci ne le sont non-seulement des autres mammiféres, mais méme de certains quadrumanes, des guenons et des macaques.’’ But it would be superfluous here to give further details on the correspondence between man and 1 *€Grosshirnwindungen des Menschen,” 2 ‘‘ Lecous sur la Physiologie” 1866, p. 1868, s. 96. The conclasions of this author, 890, as quoted by M. Dally, “‘L’Ordra as well as those of Gratiolet and Aeby, con- des Primates et le Transformisme,” 1868, cerning the brain, will be discussed by Prof. p, 29. Huxley in the Appendix alluded to in the Preface to this edition. HOMOLOGICAL STRUCTURES, 23 the higber mammals in the structure of the brain and all other parts of the body. It may, however, be worth while to specify a few points, not directly or obviously connected with structure, by which this correspondence or relationship is well shown. Man is liable to receive from the lower animals, and to com- municate to them, certain diseases, as hydrophobia, variola, the glanders, syphilis, cholera, herpes, etc.;* and this fact proves the close similarity 4 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 Rengger,® who carefully observed for a long time the Ceéus Azare in its native land, found it liable to catarrh, with the usual symptoms, and which, when often recurrent, led to consumption. ‘These monkeys suffered also from apoplexy, inflammation of the bowels, and cataract in the eye. The younger ones when shedding their 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, asI have myself seen, smoke tobacco with pleasure. Brehm asserts that the natives of northeastern Africa catch the wild baboons ‘by exposing vessels with strong beer, by which they are made drunk. He has seen some of these animals, which he kept in confinement, in this state ; and he gives a laughable account of their behavior and strange grimaces. On the following morn- ing they were very cross and dismal; they held their aching heads with both hands, and wore a most pitiable expression ; when beer or wine was offered them, they turned away with disgust, but relished the juice of lemons.’ An American mon- key, 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 cHAr,. 1] $ Dr. W. Lauder Lindsay has treated this subject at some length in the “ Journal of Mental Science,” July, 1871; and in the “* Edinburgh Veterinary Review,” July, 1858. * A Reviewer has criticised (‘* British Quarterly Review,” Oct. 1, 1871, p. 472) what I have here said with much severity and contempt ; but, as I donot use the term identity, I cannot see that I am greatly in error. There appears to mea strong analogy between the same infection or contagion pro- ducing the same result, or one closely similar, in two distinct animals, and the testing of two, distinct fluids by the same chemical reagent. 5 ‘*Naturgeschichte der Sdugethiere von Paraguay,” 1830, Ss. 50. 6 The same tastes are common to some animals much lower in the scale. Mr. A. Nicols informs me that he kept j,1 Queens- land, in Australia, three individuals of the Phaseolarctus cinereus ; and that, without having been taught in any way, they ac- quired a strong taste for rum, and for smok- ing tobacco. 7 Brehm, ‘‘Thierleben,” B. i. 1864, s. 75, 86. On the Ateles, s. 105. For other anale gous statements, see S. 25, 107. 24 THE DESCENT OF MAN. [raRT & monkeys and man, and how similarly their whole nervous system is affected. Man is infested with internal parasites, sometimes causing fatal effects ; and is plagued by external parasites, all of which belong to the same genera or families as those infesting other mammals, and in the case of scabies to the same species. Man is subject, like other mammals, birds, and even insects,® to that mysterious law which causes certain normal processes, such as gestation, as well as the maturation and duration of various diseases, to follow lunar periods. His wounds are repaired by the same process of healing; and the stumps left after the amputation of his limbs, especially during an early embryonic period, occasionally possess some power of regeneration, as in the lowest animals.” The whole process of that most important function, the reproductior. of the species, is strikingly the same in all mam- mals, from the first act of courtship by the male," to the birth and nurturing of the young. Monkeys are born ir almost as helpless a condition as our own infants; and in certain genera the young differ fully as much in appearance from the adults as do our children from their 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.8 Man differs from woman in size, bodily strength, hairiness, etc., as well asin mind, in the same manner as do the two sexes of many mammals. So that the correspondence in general structure, in the minute structure of the tissues, in 8 Dr. W. Lauder Lindsay, ‘‘ Edinburgh Vet. Review,” July, 1858, p. 13. ® With respect to insects see Dr. Laycock, **On a General Law of Vital Periodicity,” S* British Association,” 1842. Dr. Mac- culloch, ‘‘ Silliman’s North American Journal of Science,” vol. xvii. p. 305, has seen a dog suffering from tertian ague. Hereafter I shall return to this subject. ic ] have given the evidence on this head in my “ Variation of Animals and Plants under Domestication,” vol. ii. p. 15, and more could be added. 11 “Mares e diversis generibus Quadru- manorum sine dubio dignoscunt feminas humanas a maribus. Primum, credo, odor- atu, postea aspectu. Mr. Youatt, qui diu in Hortis Zoologicis (Bestiariis) medicus ani- malium erat, vir in rebus observandis cautus et sagax, hoc mihi cerdssime nrobavit, et curatores ejusdem loci et alii e ministris con- firmaverunt. Sir Andrew Smith et Brehm notabant idem in Cynoczphalo. IIlustrissi- mus Cuvier etiam narrat multa de h4e re, qua ut opinor, nihil turpius potest indicari inter omnia hominibus et Quadruma,iis com- munia. Narrat enim Cynocephalum quen- dam in furorem incidere aspectu 1eminarum aliquarum, .sed nequaquam accendi tanto © furore ab omnibus, Semper eligebat juniores, -et dignoscebat in turba, et advocabat voce gestique.” 12 This remark is made with respect te Cynocephalus and the anthropomorphous apes by Geoffroy Saint-Hilaire and F. Cuvier, ‘‘ Hist. Nat. des Mammiféres,” tom. 1. 1824. 138 Huxley, “*Man’s Place in Nature,” 1863, Ds 34 CHAP. 1.] HOMOLOGICAL STRUCTURES, 25 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-like branches, as if to carry the blood to branchiz which are not present in the higher vertebrata, though the slits on the sides of the neck still remain (f, g, fig. 1), marking their former position. At a somewhat later period, when the extremities are developed, ‘‘ the feet of liz- ards 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, _ Bays Prof. Huxley,“ ‘‘ quite in the later stages of develop- ment that the young human being presents marked differ- ences from the young ape, while the latter departs as much from the dog in its developments as the man does. Startling as this last assertion may appear to be, it is demonstrably 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 copied from two works of undoubted accuracy.” After the foregoing statements made by such high authori- ties, it would be superfluous on my part to give a number of borrowed details, showing that the embryo of man closely resembles that of other mammals. It may, however, be added, that the human embryo likewise resembles certain low forms when adult in various points of structure. For instance, the heart at first exists as a simple pulsating vessel; the excreta are voided through a cloacal passage ; and the os coccyx projects like a true tail, ‘‘extending considerably beyond the rudi- mentary legs.’’"® In the embryos of all air-breathing vertebrates, 14 “Man’s Place in Nature,” 1863, p. days old. The internal viscera have been a omitted, and the uterine appendages in both 16 The human embryo (upper fig.) is from drawings removed. I was directed to these Ecker, ‘‘Icones Phys.,” 1851-1859, tab. xxx. figures by Prof. Huxley, from whose work, fig. 2. This embryo was ten lines in length, ‘‘ Man’s Place in Nature,” the idea of giving so that the drawing is much magnified. ‘he them was taken. Hackel has also giver embryo of the dog is from Bischoff, “‘Ent- analogous drawings in his ** Schépfungs- wicklungsgeschichte des Hunde-Eies,”’ 1845, geschichte.” tab. xi. fig. 42 B. This drawing is five times 16 Prof. Wyman in “ Proc. of American @agnified, the embryo being twenty-five Acad. of Sciences,” vol. iv, 1860, p, 17. fe ae | (B)—-Vol, 2 THE DESCENT OF MAN. (PART & #1c. 1. Upper figure human embryo, from Ecker. Lower figure that of a dog, from Bischoff. a. Fore-brain, cerebral hemispheres, etc. 4. Mid-brain, corpora quadrigemina. ¢. Hind-brain, cerebellum, medulla oblongata. d. Eye. e. Ear. f First visceral arch. g- Second visceral arch. H. Vertebral columns and muscles in process of development. z. Anterior extremities. K. Posterior extremities. L. Tail or os coccyx. certain glands, called the corpora Wolffiana, correspond with and act like the kidneys of mature fishes.” Even at a later 47 Owen, “‘ Anatomy of Vertebrates,” vol. i. p. 533. CHAP. 1.3 RUDIMENTS. 29 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 fcetus 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 per- haps the most characteristic peculiarity in the human struct- ure ;’’ but in an embryo, about an inch in length, Prof. Wy- man ™ 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 ian, are identical with those of the animals immediately below him in the scale; without a doubt in these respects, he is far nearer to apes than the apes are to the dog.”’ Rudiments.—-This subject, though not intrinsically more im- portant 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 part in a rudimentary condition ; and man forms no exception to the rule. Rudimentary organs must be distinguished from those that are nascent ; though in some cases the distinction is not easy. ‘The former are either absolutely useless, such as the mammez 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 possess- ors, that we can hardly suppose that they were developed un- der the conditions which now exist. Organs in this latter state are not strictly rudimentary, but they are tending in this direction. Nascent organs, on the other hand, though not fully developed, are of high service to their possessors, and ire ca- pable of further development. Rudimentary organs are emi- 48 “Die Grosshirnwindungen des Men- ratteri rudimentali in ordine all’ origine del schen,” 1868, s. 95. uomo” (** Annuario della Soc. d. Nat.,” Mo- 4° “ Anatomy of Vertebrates,” vol. i. p. dena, 1867, p. 81), by G. Canestrini, to which 3. 2 paper I am considerably indebted. Hickel 20 “Proc. Soc. Nat. Hist.” Boston, 1863, has given admirable discussions on this vol. ix. p. 185. ; whole subject. under the title of Dysteleol- 91 *“ Man’s Place in Nature,” p. 65. ogy, in his ** Generelle Morphologie,” and 821 had written a rough copy of th’s ‘ Schépfungsgeschichte,” ghaptcr befure reading a valuable paper, *' Ca- 23 THE DESCENT OF MAN. {PART # nently variable ; and this is partly intelligible, as they are use- less, 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 re- appearance 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 maturity), and also inheritance at a corresponding period of life. The term ‘‘ dis- ’ does not relate merely to the lessened action of muscles, but includes a diminished flow of blood to a part or organ, from being subjected to fewer alternations of pressure, or from becoming in any way less habitually active. Rudiments, how- ever, may occur in one sex of those parts which are normally present in the other sex ; and such rudiments, as we shall here- after see, have often originated in a way distinct from those here referred to. In some cases, organs have been reduced by means of natural selection, from having become injurious to the species under changed habits of life. The process of reduction is probably often aided through the two principles of compen- sation and economy of growth ; but the later stages of reduc- tion, after disuse has done all that can fairly be attributed to it, and when the saving to be effected by the economy of growth would be very small,” are difficult to understand. The final and complete suppression of a part, already useless and much reduced in size, in which case neither compensation nor economy can come into play, is perhaps intelligible by the aid of the hypothesis of pangenesis. But as the whole subject of rudimentary organs has been discussed and illustrated in my former works, I need here say no more on this head. Rudiments of various muscles have. been observed in many parts of the human body,” and not a few muscles which are regularly present in some of the lower animals can occasionally be detected in man in a greatly reduced condition. Every- one must have noticed the power which many animals, espe- cially horses, possess of moving or twitching their skin ; and this 23 Some good criticisms on this subject des Sciences Nat.” 3d series. Zoolog. 1852, have been given by Messrs. Murie and tom. xviii. p. 13) describes and figures rudi- Mivart, in ‘‘ Transact. Zoolog. Soc.” 1869, ments of what he calls the “ muscle pédieux wol. vil. p. 92. de la main,” which he says is sometimes 24 “ Variation of Animals and Plants un- “‘ infiniment petit.” Another muscle, called der Domestication,” vol. ti. pp. 317 and 397. ‘‘le tibial postérieur,” is generally quite See also ‘‘ Origin of Species,” 5th edit. p. absent in the hand, but appears trom time 538: to time in a more or less rudimentary con: “or instance M. Richard (‘Annales dition. CHAP, I.} RUDIMENTS. 29, is effected by the panniculus carnosus. Remnants of this mus- cle in an efficient state are found in various parts of our bodies; for instance, the muscle on the forehead, by which the eye- brows are raised. The p/atysma myoides, which is well devel- oped on the neck, belongs to this system. Prof. Turner, of Edinburgh, has occasionally detected, as he informs me, mus- cular fasciculi in five different situations, namely in the axlile, near the scapule, etc., all of which must be referred to the system of the panniculus. He has also shown” that the mus- culus sternalts or sternalts brutorum, which is not an extension of the rectus abdominals, but is closely allied to the pannicu- Jus, occurred in the proportion of about three per cent. in upward 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 ar- rangement.’’ 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 Can- dolle 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 be- came divided eight generations ago into two branches ; so that the head of the above-mentioned branch is cousin in the sev- enth degree to the head of the other branch. This distant cousin resides in another part of France, and on being asked whether he possessed the same faculty, immediately exhibited his power. This case offers a good illustration how persistent may be the transmission of an absolutely useless faculty, prob- ably 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 of the panniculus ; they are also variable in develop- 36 Prof. W. Turner, ‘* Proc. Royal Sac. | 37 See my ‘Expression of the Emotions Edinburgh,” 1866-67, p. 65. in Man and Animals,” 1872, p. 144 30 THE DESCENT OF MAN. [enRT L «ent, or at least in function. I have seen one man who could draw the whole ear forward ; other men can draw it upward ; another who could draw it backward ; * 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 toward them, could recover some power of movement by repeated trials. The power of erecting and directing the shell of the ears to the various points of the compass is no doubt of the highest service to many animals, as they thus perceive the direction of danger; but I have never heard, on sufficient evi- dence, of a man who possessed this power, the one which might be of use to him. The whole external shell may be con- sidered a rudiment, together with the various folds ané prom- inences (helix and anti-helix, tragus and anti-tragus, etc.) which in the lower animals strengthen and support tae ear when erect, without adding much to its weight. Some au- thors, however, suppose that the cartilage of the sheli serves to transmit vibrations to the acoustic nerve; but Mr. Foyn- bee,” after collecting all the known evidence on this head, con- cludes that the external shell is of no distinct use. The ears of the chimpanzee and orang are curiously like those of man, and the proper muscles are likewise but very slightly developed.” I am also assured by the keepers in the Zoological Gardens that these animals never move or erect their ears ; so that they are in an equally rudimentary condition with those of man, ar far as function is concerned. Why these animals, as weil as the progenitors of man, should have lost the power of erecting their ears, we cannot say. It may be, though I am not satis- fied with this view, that, owing to their arboreal habits and great strength, they were but little exposed to danger, and so during a lengthened period moved their ears but little, and thus gradually lost the power of moving them. This would be a parallel case with that of those large and heavy birds which, from 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. The inability to move the ears in man and several apes is, however, partly compensated by the freedom with which they can move the head in a horizon- 28 Canestrini quotes Hyrtl. (‘‘Annuario me that he had lately been experimenting on della Soc. dei Naturalisti,” Modena, 1867, p. the function of the shell of the ear, and has 97) to the same effect. come to nearly the same conclusion as that 39 “The Diseases of the Ear,” by J. given here. Toynbee, F.R.S., 1860, p. 12. A distin- — %° Prof. A. Macallister, “‘Annals and guished physiologist, Prof. Preyer. informs Mag. c‘ Nat, History,” vol. vii., 1871, p. 342 CHAP. 1.] RUDIMENTS, 34 . tal plane, so as to catch sounds from all directions. It has been asserted that the ear of man alone possesses a lobule; but ‘ 66. 80 THE DESCENT OF MAN, ePART ©! races, that of the Bushmen, maintains itself in Southern Africa, as do the dwarfed Esquimaux in the Arctic regions. The an- cestors of man were, no doubt, inferior in intellect, and probably in social disposition, to the lowest existing savages ; but it is quite conceivable that they might have existed, or even flourished, if they had advanced in intellect, while gradually losing their brute-like powers, such as that of climb- ing trees, etc. But these ancestors would not have been exposed to any special danger, even if far more helpless and defenceless than any existing savages, had they inhabited some warm continent or large island, such as Austral'a, New Guinea, or Borneo, which is now the home of the orang. And natural selection arising from the competition of tribe with tribe, in some such large area as one of these, together with the inher- ited effects of habit, would, under favorable conditions, have sufticed to raise man to his present high position in the organic scale. CHAPTER III. COMPARISON OF THE MENTAL POWERS OF MAN AND THE LOWER ANIMALS. The difference in mental power between the highest ape and the lowest savage, immense — Certain instincts in common — The emotions — ( uriosity—Imitation-—Attention— Memory— Imagination— Reason—~ I™ogressive Improvement—Tools and weapons used by animals— 4bstraction, self- consciousness— Language—Sense of beauty—Belief in God, spiritual agencies, superstitions. WE have seen in the last two chapters that man bears in his bodily structure clear traces of his descent from some lower form ; but it may be urged that, as man differs so greatly in his mental power from all other animals, there must be some error in this conclusion. No doubt the difference in this respect is enormous, even if we compare the mind of one of the lowest savages, who has no words to express any number higher than four, and who uses hardly any abstract terms for common objects or for the affections,! with that of the most highly organized ape. The difference would, no doubt, still remain immense, even 1f one of the higher apes had been improved er civilized See the evidence on those points, as given by Lubbock, “ Prehistoric Limes,” pe % Bd CHAP, U1.) MENTAL POWERS. 81 as much as a dog has been in comparison with its parent-form, the wolf or jackal. The Fuegians rank among the lowest bar- barians ; but I was continually struck with surprise how closely the three natives on board H.M.S. Beagle, who had lived some years in England, and could talk a little English, resembled us in disposition and in most of our mental faculties. If no organic being excepting man had possessed any mental power, or if his powers had been of a wholly different nature from those of the lower animals, then we should never have been able to convince ourselves that our high faculties had been gradually developed. But it can be shown that there is no fundamental difference of this kind. We must also admit that there is a much wider interval in mental power between one of the lowest fishes, as a lamprey or lancelet, and one of the higher apes, than between an ape and man; yet this interval is filled up by num- berless gradations. Nor is the difference slight in moral disposition between a barbarian, such as the man described by the old navigator Byron, who dashed his child on the rocks for dropping a basket of sea-urchins, and a Howard or Clarkson ; and in intellect, be- tween a savage who uses hardly any abstract terms and a New- ton or Shakspeare. Differences of this kind between the highest men of the highest races and the lowest savages are connected by the finest gradations. Therefore it is possible that they _might pass and be developed into each other. _ My object in this chapter is to show that there is no funda. mental difference between man and the higher mammals in their | mental faculties. Each division of the subject might have been extended into a separate essay, but must here be treated briefly. As no classification of the mental powers has been universally accepted, I shall arrange my remarks in the order most con- venient for my purpose ; and will select those facts which have struck me most, with the hope that they may produce some effect on the reader. With respect to animals very low in the scale, I shall give some additional facts under Sexual Selection, showing that their mental powers are much higher than might have been expected. The variability of the faculties in the individuals of the same species is an important point for us, and some few illustrations will here be given. But it would be superfluous to enter into many details on this head, for I have found, on frequent inquiry, _ that it is the unanimous opinion of all those who have long at- fended to animals of many kinds, including birds, that the ine, 82 THE DESCENT OF MAN. (rarr | ; dividuals differ greatly in every mental characteristic, In what manner the mental powers were first developed in the lowest organisms is as hopeless an inquiry as how life itself first originated. These are problems for the distant future, if they are ever to be solved by man. As man possesses the same senses as the lower animals, his fundamental intuitions must be the same. Man has also some few instincts in common, as that of self-preservation, sexual love, the love of the mother for her new-born offspring, the desire possessed by the latter to suck, and so forth. But man, per- haps, has somewhat fewer instincts than those possessed by the animals which come next to him in the series. The orang in the Eastern islands, and the chimpanzee in Africa, build plat- forms on which they sleep ; and, as both species follow the same habit, it might be argued that this was due to instinct, but we cannot feel sure that it is not the result of both animals hav- ing similar wants, and possessing similar powers of reasoning. These apes, as we may assume, avoid the many poisonous fruits of the tropics, and man has no such knowledge; but as our domestic animals, when taken to foreign lands, and whew first turned out in the spring, often eat poisonous herbs, which they afterward avoid, we cannot feel sure that the apes do not learn from their own experience or from that of their parents what fruits to select. It is, however, certain, as we shall presently see, that apes have an instinctive dread of serpents, and prohabhy of other dangerous animals. The fewness and the comparative simplicity of the instincts - in the higher animals are remarkable in contrast with those of the lower animals. Cuvier maintained that instinct and intelli- gence stand in an inverse ratio to each other; and some have thought that the intellectual faculties of the higher animals have been gradually developed from their instincts. But Pouchet, in an interesting essay,” has shown that no such inverse ratio really exists. Those insects which possess the most wonderful instincts are certainly the most iatelligent. In the vertebrate series, the least intelligent members, namely fishes and amphi- — bians, do not possess complex instincts; and among mammals the animal most remarkable for its instincts, namely, the beaver, is highly intelligent, as will be admitted by everyone who has read Mr. Morgan’s excellent work.* Although the first dawnings of intelligence, according to Mr. 2 “**TInstinct chez les Insectes.” “Revue 3 “The American Beaver and his Works,” Ges Dezx Mondes,” Web., 1870, P» 690 1868, : CHAP, fi1.] MENTAL POWERS, 83 cierbert Spencer,‘ have been developed through the multiplica- tion and co-ordination of reflex actions, and although many of the simpler instincts graduate into reflex actions, and can hardly oe distinguished from them, as in the case of young animals sucking, yet the more complex instincts seem to have originated independently of intelligence. I am, however, very far from wishing to deny that instinctive actions may lose their fixed and antaught character, and be replaced by others performed by the nid of the free will. On the other hand, some intelligent actions, after being performed during several generations, become con- verted into instincts and are inherited, as when birds on oceanic islands learn to avoid man. ‘These actions may then be said to be degraded in character, for they are no longer performed through reason or from experience. But the greater number of the more complex instincts appear to have been gained in a wholly different manner, through the natural selection of varia- tions of simpler instinctive actions. Such variations appear to arise from the same unknown causes acting on the cerebral or- ganization which induce slight variations or individual differ-- ences in other parts of the body; and these variations, owing to our ignorance, are often said to arisespontaneously. Wecan, I think, come to no other conclusion with respect to the origin of the more complex instincts, when we reflect on the marvellous instincts of sterile worker-ants and bees, which leave no off- spring to inherit the effects of experience and of modified habits. Although, as we learn from the above-mentioned insects and the beaver, a high degree of intelligence is certainly compatible with complex instincts, and although actions, at first learned voluntarily, can soon through habit be performed with the quickness and certainty of a reflex action, yet it is not improb- able that there is a certain amount of interference between the development of free intelligence and of instinct—which latter “implies: some inherited modification of the brain. Little is known about the functions of the brain, but we can perceive that as the intellectual powers become highly developed, the various parts of the brain must be connected by very intricate channels of the freest intercommunication; and as a conse- quence, each separate part would perhaps tend to be less well fitted to answer to particular sensations or associations in a defi- nite and inherited—that is instinctive—manner. ‘There seems even to exist some relation between a low degree of intelligence and a strong tendency to the formation of fixed, though not in- * “The Principles of Psychology,” 2d edit., 1870, pp. 412-442 84. THE DESCENT OF MAN. [PART & herited, habits; for, as a sagacious physician remarked to me, persons why aré slightly imbecile tend to act in everything by routine or habit, and they are rendered much happier if this is encouraged. I have thought this digression worth giving, because we may- easily underrate the mental powers of the higher animals, and especially of man, when we compare their actions founded on the memory of past events, on foresight, reason, and imagina- tion, with exactly similar actions instinctively performed by the lower animals; in this latter case the capacity of performing such actions has been gained, step by step, through the varia- bility of the mental organs and natural selection, without any conscious intelligence on the part of the animal during each successive generation. No doubt, as Mr. Wallace has argued, much of the intelligent work done by man is due to imitation and not to reason ; but there is this great difference between his actions and many of those performed by the lower animals, namely, that man cannot, on his first trial, make, for instance, a stone hatchet or a canoe, through his power of imitation. He has to learn his work by practice ; a beaver, on the other hand, can make its dam or canal, anda bird its nest, as well, or nearly as well, and a spider its wonderful web quite as well,® the first time it tries, as when old and experienced. To return to our immediate subject: the lower animals, like man, manifestly feel pleasure and pain, happiness and misery. Happiness is never better exhibited than by young animals, such as puppies, kittens, lambs, etc., when playing together, like our own children. Even insects play together, as has been described by that excellent observer, P. Huber,’ who saw ants chasing and pretending to bite each other, like so many puppies. The fact that the lower animals are excited by the same emotions as ourselves is so well established, that it will not be necessary to weary the reader by many details. Terror acts in the same manner‘on them as on us, causing the muscles to tremble, the heart to palpitate, the sphincters to be relaxed, and — the hair to stand on end. Suspicion, the offspring of fear, is eminently characteristic of most wild animals. It is, I think, impossible to read the account given by Sir E. Tennent, of the behavior of the female elephants, used as decoys, without ad- § «‘Contributions to the Theory of Nat- work, ‘Harvesting Ants and Trap-door ural Selection,” 1870, p. 212. Spiders, ”? 1873, pp. 126, 128. 6 For the evidence on this head, see Mr. ‘Recherches sur les Mceurs des Four 3. Traherne Moggridge’s most interesting mis,’’ 1810, P+ 172. CHAP. 111} AENTAL POWERS. 85 mitting that they intentionally practise deceit, and well know what they are about. Courage and timidity are extremely variable qualities in the individuals of the same species, as is plainly seen in our dogs. Some dogs and horses are ill-tem- pered, and easily turn sulky ; others are good-tempered ; and these qualities are certainly inherited. _ Everyone knows how liable animals are to furious rage, and how plainly they show it. Many, and probably true, anecdotes have been published on the long-delayed and artful revenge of various animals. The accurate Rengger, and Brehm® state that the American and African monkeys which they kept tame certainly revenged themselves. Sir Andrew Smith, a zoologist whose scrupulous accuracy was known to many persons, told me the following story of which he was himself an eye-witness: At the Cape of Good Hope an officer had often plagued a certain baboon, and the animal, seeing him approaching one Sunday for parade, poured water into a hole and hastily made some thick mud, which he skilfully dashed over the officer as he passed by, to the amusement of many bystanders. For long afterward the baboon rejoiced and triumphed whenever he saw his victim. The love of a dog for his master is notorious; as an old writer quaintly says,® <‘ A dog is the only thing on this earth “hat luvs you more than he luvs himself.’’ In the agony of death a dog has been known to caress his master, and everyone has heard of the dog suffering under vivi- section, who licked the hand of the operator; this man, unless the operation was fully justified by an increase of our knowl- edge, or unless he had a heart of stone, must have felt remorse to the last hour of his life. As Whewell*® has well asked, ‘‘ who that reads the touching instances of maternal affection, related so often of the women of all nations, and of the females of all animals, can doubt that the principle of action is the same in the two cases?’’ We see maternal affection exhibited in the most trifling details; thus Rengger observed an American monkey (a Cebus) care- fully driving away the flies which plagued her infant; and Duvaucel saw a Hylobates washing the faces of her young ones in a stream. So intense is the grief of female monkeys for the loss of their young, that it invariably caused the death of cer- 8 Allthe following statements, given on the ® Quoted by Dr. Lauder Lindsay, in his authority of these two naturalists, are taken ‘‘ Physiology of Mind in the Lower Ani from Rengger’s ‘‘Naturgesch. der Sduge- mals ;’’ ‘ Journal of Mental Science,” April thiere von Paraguay,’ 1830, s. 41-57, and 1871, p. 38. &om Brehm’s ‘' Thierleben,” B. i. s. 10-87 10 “ Bridgewater Treatise,” p, 263 ix) ' THE DESCENT OF MAN, {PART LE tain kinds kept under confinement by Brehm in N. Africa, Orphan monkeys were always adopted dnd carefully guarded by the other monkeys, both males and females. One female baboon had so capacious a heart that she not only adopted young monkeys of other species, but stole young dogs and cats, which she continually carried about. Her kindness, however, did not go so far as to share her food with her adopted off- spring, at which Brehm was surprised, as his monkeys always divided everything quite fairly with their own young ones. An adopted kitten scratched this affectionate baboon, who cer- tainly had a fine intellect, for she was much astonished at be- ing scratched, and immediately examined the kitten’s feet, and without more ado bit off the claws." In the Zoclogical Gar- dens, I heard from the keeper that an old baboon (C. chacma) had adopted a Rhesus monkey; but when a young drill and mandrill were placed in the cage, she seemed to perceive that these monkeys, though distinct species, were her nearer rela- tives, for she at once rejected the Rhesus and adopted both of them. ‘The young Rhesus, as I saw, was greatly discontented at being thus rejected, and it would, like a naughty child, an- noy and attack the young Grill and mandrill whenever it could do so with safety ; this conduct exciting great indignation in’ the old baboon. Monkeys wiil also, according to Brehm, de- fend their master when attacked by any one, as well as dogs to whom they are attached, from the attacks of other dogs. But _ we here trench on the subjects of sympathy and fidelity, to which I shall recur. Some of Brehm’s monkeys took much delight in teasing a certain old dog whom they disliked, as weil as other animals, in various ingenious ways. Most of the more complex emotions are common to the higher animals and ourselves. Everyone has seen how jealous a dog is of his master’s affection, if lavished on any other creat- ure; and I have observed the same fact with monkeys. This shows that animals not only love, but have desire to be loved. Animals manifestly feel emulation. They love approbation or praise ; and a dog carrying a basket for his master exhibits in | a high degree self complacency or pride. ‘There can, I think, be no dcubt that a dog feels shame, as distinct from fear, and something very like modesty when begging too often for food. A great dog scorns the snarling of a little dog, and this may be 22 A critic, without any grounds (‘‘Quar- Therefore I tried, and found that I could terly Review,” July, 1871, p. 72), disputes readily seize with my own teeth the sharp the possibility of this act as described by httle claws of a kitten nearly five weeks old. Brehm, for the sake of discrediting my work. CHAP, 111.§ MENTAL POWERS. 89 called magnanimity. Several observers have stated that mon- keys certainly dislike being laughed at; and they sometimes invent imaginary offences. In the Zoological Gardens I saw a baboon who always got into a furious rage when his keeper took out a letter or book and read it aloud to him; and his rage was so violent that, as I witnessed on one occasion, he bit his own leg till the blood flowed. Dogs show what may be fairly called a sense of humor, as distinct from mere play ; if a bit of stick or other such object be thrown to one, he will often carry it away for a short distance; and then, squatting down with it on the ground close before him, will wait until his master comes quite close to take it away. The dog will then seize it and rush away in triumph, repeating the same manceuvre, and evidently enjoying the practical joke. 7 We will now turn to the more intellectual emotions and facul- ties, which are very important, as forming the basis for the de- velopment of the higher mental powers. Animals manifestly enjoy excitement, and suffer from ennui, as may be seen with dogs, and, according to Rengger, with monkeys. All animals feel Wonder, and many exhibit Curiosity. They sometimes suffer from this latter quality, as when the hunter plays antics and thus attracts them; I have witnessed this with deer, and so it is with the wary chamois, and with some kinds of wild- ducks. Brehm gives a curious account of the instinctive dread which his monkeys exhibited for snakes; but their. curiosity was so great that they could not desist from occasion- ally satiating their horror in a most human fashion, by lifting up the lid of the box in which the snakes were kept. I was so much surprised at his account, that I took a stuffed and coiled- up snake into the monkey-house at the Zoological Gardens, and the excitement thus caused was one of the most curious specta- cles which I ever beheld. Three species of Cercopithecus were the most alarmed ; they dashed about their cages and uttered sharp signal cries of danger, which were understood by the other monkeys. A few young monkeys and one old Anubis baboon alone took no notice of the snake. I then placed the stuffed specimen on the ground in one of the larger compart- ments. Aftera time all the monkeys collected round it ina large circle, and, staring intently, presented a most ludicrous appear- ance. They became extremely nervous ; so that when a wooden ball, with which they were familiar as a plaything, was acci- dentally moved in the straw, under which it was partly hidden, they all instantly started away. ‘These monkeys behaved very 88 THE DESCENT OF MAN. [PART & differently when a dead fish, a mouse,” a living turtle, and other new objects were placed in their cages ; for, though at first frightened, they soon approached, handled, and examined them. I then placed a live snake in a paper bag, with the mouth loosely closed, in one of the larger compartments. One of the monkeys immediately approached, cautiously opened the bag a little, peeped in, and instantly dashed away. ‘Then I witnessed what Brehm has described, for monkey after monkey, with head raised high and turned on one side, could not resist taking amomentary peep into the upright bag, at the: dreadful object lying quietly at the bottom. It would almost appear as if monkeys had some notion of zoological affinities, for those kept by Brehm exhibited a strange, though mistaken, instinc- tive dread of innocent lizards and frogs. An orang, also, has been known to be much alarmed at the first sight of a turtle.” The principle of /mz¢ation is strong in man, and especially, as | have myself observed, with savages. In certain morbid states of the brain this tendency is exaggerated to an extraor- dinary degree; some hemiplegic patients and others, at the~ commencement of inflammatory softening of the bra‘a, un- consciously imitate every word which is uttered, whether in their own or in a foreign language, and every gesture Wr action which is performed near them. Desor® has remavked that no animal voluntarily imitates an action performed by man, until in the ascending scale we come to monkeys, which are well known to be ridiculous mockers. Animals, however, some- times imitate each other’s actions ; thus two species of wolves, which had been reared by dogs, learned to bark, as does some- times the jackal,’© but whether this can be called voluntary imitation is another question. | Birds imitate the songs of their parents, and sometimes of other birds ; and parrots are notori- ous imitators of any sound which they often hear. Dureau de ia Malle gives an account™ of a dog reared by a cat, whe iearned to imitate the well-known action of a cat licking her paws, and thus washing her ears and face; this was also wit- nessed by the celebrated naturalist, Audouin. I have received » several confirmatory accounts; in one of these, a dog had not been suckled by a cat, but had been brought up with one, to- 12 T have given a short account of their 18 Quoted by Vogt, “ tery sur les behavior on this occasion in my ‘ Expres- Microcéphales,” 1867, p sion nh the Emotions,” P. 4 16 “+ The Variation ‘of Animals BS Plants W. C. L. Martin, “‘ Nat. Hist. of Mam- under Domestic ition,” vol. i. snalia” 1841, P- 405 17 ** Annalr « des Se. Nat. isP ‘(xt Soria, ‘4 Dr, Bateman On Aphasia,” 1870, Pp, tom. xxii. Pp." ge Tae -_ CHAP. IIL.) MENTAL POWERS, 59 gether with kittens, and had thus acquired the above habit, which he ever afterward practised during his life of thirteen years. Dureau dela Malle’s dog likewise learned from the kittens to play with a ball by rolling it about with his fore- paws, and springing on it. A correspondent assures me that a cat in his house used to put her paws into jugs of milk hav- ing too narrow a mouth for her head. A kitten of this cat soon learned the same trick, and practised it ever afterward, whenever there was an opportunity. The parents of many animals, trusting to the principle of imitation in their young, and more especially to their instinctive or inherited tendencies, may be said to educate them. We see this when a cat brings a live mouse to her kittens ; and Dureau de la Malle has given a curious account (in the papet above quoted) of his observations on hawks which taught their young dexterity, as well as judgment of distances, by first dropping through the air dead mice and sparrows, which the young generally failed to catch, and then bringing them live birds and letting them loose. Hardly any faculty is more important for the intellectual progress of man than A/tention. Animals clearly manifest this power, as when a cat watches by a hole and prepares to spring on its prey. Wild animals sometimes become so absorbed when thus engaged, that they may be easily approached. Mr. Bartlett has given me a curious proof how variable this faculty is in monkeys. A man who trains monkeys to act in plays used to purchase common kinds from the Zoological Society at the price of five pounds for each ; but he offered to give double the price, if he might keep three or four of them for a few days, in erder to select one. When asked how he could possibly learn so goon whether a particular monkey would turn out a good actor, he answered that it all depended on their power of attention. If, when he was talking and explaining anything to a monkey, its attention was easily distracted, as by a fly on the wall or other trifling object, the case was hopeless. If he tried by punishment to make an inattentive monkey act, it turned sulky. On the other hand, a monkey which carefully attended to him could always be trained. It is almost superfluous to state that animals have excellent Memories for persons and places. A baboon at the Cape of Good Hope, as I have been informed by Sir Andrew Smith, recognized him with joy after an absence of nine months. I had adog who was savage and averse to all strangers, and I purposely tried his iO THE DESCENT OF MAN. (PART t memory after an absence of five years and two days. I went near the stable where he lived, and shouted to him in my old manner ; he showed no joy, but instantly followed me out walk- ing, and obeyed me, exactly as if I had parted with him only half an hour before. A train of old associations, dormant during five years, had thus been instantaneously awakened in his mind. Even ants, as P. Huber has clearly shown, recognized their fellow-ants belonging to the same community after a separation of four months. Animals can certainly by some means judge of the intervals of time between recurrent events. The /magination is one of the highest prerogatives of man. By this faculty he unites former images and ideas, independently of the will, and thus creates brilliant and novel results. A poet, as Jean Paul Richter remarks, ‘* who must reflect whether he shall make a character say yes or no—to the devil with him ; he is only a stupid corpse.’’ Dreaming gives us the best notion of this power; as Jean Paul again says, ‘‘‘The dream is an in- voluntary art of poetry.’’ The value of the products of our imagination depends of course on the number, accuracy, and clearness of our impressions, on our judgment and -taste in selecting or rejecting the involuntary combinations, and to a certain extent on our power of voluntarily combining them. As dogs, cats, horses, and probably all the higher animals, even birds,” have vivid dreams, and this is shown by their movements and the sounds uttered, we must admit that they possess some power ofimagination. There must be something special which causes dogs to howl in the night, and especially during moon- light, in that remarkable and melancholy manner called baying. All dogs do not do so; and, according to Houzeau,* they do -not then look at the moon, but at some fixed point near the horizon. Houzeau thinks that their imaginations are disturbed by the vague outlines of the surrounding objects, and conjure up before them fantastic images: if this beso, their feelings may almost be called superstitious. Of all the faculties of the human mind, it will, I presume, be admitted that Reason stands at the summit. Only a few per~ sons now dispute that animals possess some power of.reasoning. Animals may constantly be seen to pause, deliberate, and re- solve. Itis a significant fact, that the more the habits of any 18 “Tes Mceurs des Fourmis,” 1810, p. 1862, p. xxi. Houzeau says that his paro- 150. keets and canary- -birds dreamt: ** Facultés 19 Quoted in Dr. Maudsley’s ‘‘Physiology Mentales,” tom. ii. p. 136. and Pathology of Mind, ”” 1868, pp. 19, 220. 2 ** Facultés,.M entales des Animavx,” "20 Dr. Jerdon, “ Birds of India,” vol. i, 1872, tom. ii. P+ 18%, CHAP. III.} ' MENTAL POWERS, er particular animal are studied by a naturalist, the more he at- tributes to reason and the less'to unlearnt instincts.” In future chapters we shall see that some animals extremely low in the scale:apparently display a certain amount of reason. No doubt it is often difficult to distinguish between the power of reason and that of instinct. For instance, Dr. Hayes, in his work on ‘« The Open Polar Sea,’’ repeatedly remarks that his dogs, in- stead of continuing to draw the sledges in a compact body, diverged and separated when they came to thin ice, so that their weight might be more evenly distributed. This was often the first warning which the travellers received that the ice was becoming thin and dangerous. Now, did the dogs act thus from the experience of each individual, or from the example of the older and wiser dogs, or from an inherited habit, that is, from instinct? ‘This instinct may possibly have arisen since the time, long ago, when dogs were first employed by the natives in drawing their sledges ; or the Arctic wolves, the parent-stock of the Esquimau dog, may have acquired an instinct impell- ing them not to attack their prey in a close pack, when on thin ice. We can only judge by the circumstances under which actions are performed, whether they are due to instinct, or to reason, or to the mere association of ideas: this latter principle, how- ever, is intimately connected with reason. A curious case has been given by Prof. Mobius,* of a pike, separated by a plate of glass from an adjoining aquarium stocked with fish, and who often dashed himself with such vioience against the glass in trying to catch the other fishes, that he was sometimes com- pletely stunned. ‘The pike went on thus for three months, but at last learned caution, and ceased to do so. The plate of glass was then removed, but the pike would not attack these particu- lar fishes, though he would devour others which were afterward introduced ; so strongly was the idea of a violent shock associ- ated in his feeble mind with the attempt on his former neighbors. If asavage, who had never seen a large plate-glass window, were to dash himseif even once against it, he would for a long time afterward associate a shock with a window-frame ; but, very differently from the pike, he would probably reflect on the nature of the impediment, and be cautious under analogous circumstances. Now with monkeys, as we shall presently see, 92 Mr. L, H. Morgan’s excellent work he goes too far in underrating the power of on “‘ The American Beaver,” published in Instinct. 1868, offers a good illustration of this re- 28 ** Die Bewegungen der Lhiere,” ett mark. Icannothelp thinking, however, that 1873, py ide 02 THE DESCENT OF MAN. {PART 4% a painfwl or merely a disagreeable impression, from an action once performed, is sometimes sufficient to prevent the animal from repeating it. If we attribute this difference between the monkey and the pike solely to the association of ideas being so much stronger and more persistent in the one than the other, though the pike often received much the more severe injury, can we maintain in the case of man that a similar difference implies the possession of a fundamentally different m nd? Houzeau relates *4 that, while crossing a wide and arid plain in Texas, his two dogs suffered greatly from thirst, and that between thirty and forty times they rushed down the hollows to search for water. ‘These hollows were not valleys, and there were no trees in them, or any other difference in the vegetation, and as they were absolutely dry there could have been no smell of damp earth. The dogs behaved as if they knew that a dip in the ground offered them the best chance of finding water, and Houzeau has often witnessed the same behavior in other animals. I have seen, as I daresay have others, that when a small object is thrown on the ground beyond the reach of one of the elephants in the Zoological Gardens, he blows through his trunk on the ground beyond the object, so that the current reflected on all sides may drive the object within his reach.. Again, a we.l-known ethnologist, Mr. Westropp, informs me that he ob- served in Vienna a bear deliberately making with his paw a current in some water, which was close to the bars of his cage, so as to draw a piece of floating bread within his reach. These actions of the elephant and bear can hardly be attributed to in- stinct or inherited habit, as they would be of little use to an animal in astate of nature. Now, what is the difference be- tween such actions, when performed by an uncultivated man, and. by one of the higher animals ? Tne savage and the dog have often found water at a low level, and the coincidence under such circumstances has become asso- ciated in their minds, A cultivated man would perhaps make ~ some general proposition on the subject ; but from all that we know of savages it is extremely doubtful whether they would do so, and a dog certainly would not. But a savage, as well asa dog, would search in the same way, though frequently dis- appointed ; and in both it seems to be equally an act of rea- gon, whether or not any general proposition on the subject is 94 “‘Facultés Mentales des Animaux,” 1872, tom. ii. p. 205. CHAP, U1] MENTAL POWERS. 93 consciously placed before the mind.* The same would apply ta the elephant and the bear making currents in the air or water. ‘The savage would certainly neither know nor care by what law the desired movements were effected ; yet his act would be guided by a rude process of reasoning, as surely as would a philosopher in his longest chain of deductions. There would no doubt be this difference between him and one of the higher animals, that he would take notice of much slighter circum- stances and conditions, and would observe any connection between them after much less experience, and this would be of paramount importance. I kept a daily record of the actions of one of my infants, and when he was about eleven months old, and before he could speak a single word, I was continually struck with the greater quickness with which all sorts of objects and sounds were associated together in his mind, compared with that of the most intelligent dogs I ever knew. But the higher animals differ in exactly the same way in this power of associa- tion from those low in the scale, such as the pike, as well as in that of drawing inferences and of observation. The promptings of reason, after very short experience, are well shown by the following actions of American monkeys, whicl, stand low in their order. Rengger, a most careful observer, states that when he first gave eggs to his monkeys in Paraguay, they smashed them, and thus lost much of their contents ; after- ward they gently hit one end against some hard body, and picked off the bits of shell with their fingers. After cutting themselves only ozce with any sharp tool they would not touch it again, or would handle it with the greatest caution. Lumps of sugar were often given them wrapped up in paper; and Rengger sometimes put a live wasp in the paper, so that in hastily unfolding it they got stung ; after this had omce happened, they always first held the packet to their ears to detect any movement within. The following cases relate to dogs. Mr. Colquhoun” winged two wild-ducks, which fell on the further side of a stream ; his retriever tried to bring over both at once, but could not suc- ceed ; she then, though never before known to ruffle a feather, 28 Prof. Huxley has analyzed with admi- rable clearness the mental steps by which a man, as well as a dog, arrives at a conclu- “The Naturalist in Nicaragua,” 1874 (p. 119), likewise describes various actions of a tamed Cebus, which, I think, clearly show sion in a case analogous to that given in my text. See his article, ‘* Mr. Darwin’s Critics,” in the ‘Contemporary Review,” Nov., 1871, p. 462, and in his “ Critiques and eg aS 1873, p. 279. %6 Mr. Belt, his most interesting work that this animal possessed some reasoning power. 27 ** The Moor and the Loch,” p. 45. Col. ee on “‘ Dog Breaking,” 1850, pe 04 deliberately killed one, brought over the other, and returned for the dead bird. Col. Hutchinson relates that two partridges were shot at once, one being killed, the other wounded ; the latter ran away, and was caught by the retriever, who on her return came across the dead bird; ‘‘she stopped, evidently greatly puzzled, and after one or two trials, finding she could not take it up without permitting the escape of the winged bird, she considered a moment, then deliberately murdered it by giving it a severe crunch, and afterward brought away both together. . This was the only known instance of her ever hav - ing wilfully injured any game.’’ Here we have reason, though not quite perfect, for the retriever might have brought the wounded bird first and then returned for the dead one, asin the case of the two wild-ducks. I give the above cases, as resting on the evidence of two independent witnesses, and because in both instances the retrievers, after deliberation, broke through a habit which is inherited by them (that of not ‘killing the game retrieved), and because they show how strong their reasoning faculty must have been to overcome a fixed habit. I will conclude by quoting a remark by the illustrious Hum- boldt.% ‘‘ The muleteers in South America say, ‘I will not give you the mule whose step is easiest, but Za mas racional~ the one that reasons best ;’’’ and, as he adds, ‘‘ this popular ex- pression, dictated by long experience, combats the system of animated machines better perhaps than all the arguments of speculative philosophy.’’ Nevertheless some writers even yet deny. that the higher animals possess a trace of reason; and they endeavor to explain away, by what appears to be mere verbiage,” all such facts as those above given. It has, I think, now been shown that man and the higher animals, especially the Primates, have some few instincts in common. All have the same senses, intuitions, and sensations —similar passions, affections, and emotions, even the more complex ones, such as jealousy, suspicion, emulation, gratitude, and magnanimity ; they practise deceit and are revengeful ; they are sometimes susceptible to ridicule, and even have a THE DESCENT OF MAN. {PART & 28 “ Personal Narrative,” Eng. translat., vol. iii. p. 106. 29 [| am glad to find that so acute a reasoner as Mr. Leslie Stephen (‘‘ Darwin- ism and Divinity, Essays on Free-think- ing,” 1873, p- 80), in speaking of the sup- posed impassable barrier between the minds of man and the lower animals, says, ‘‘ The distinctions, indeed, which have been ' @grawn, seem to us to rest upon no better foundation than a great many other meta- physical distinctions ; that is, the assump- tion that because you can give two: things different names, they must therefore have different natures. It is difficult to under- stand how anybody who has ever kept a dog or seen an elephant can have any doubts as to an animal’s power of performe ing the essential processes of reasoning.” CHAP. IIT.) MENTAL POWERS. 95 sense of humor ; they feel wonder and curiosity ; they possess the same faculties of imitation, attention, deliberation, choice, memory, imagination, the association of ideas, and reason, though in very different degrees. The individuals of the same species graduate in intellect from absolute imbecility to high excellence. They are also liable to insanity, though far less © often than in the case of man. Nevertheless, many authors have insisted that man is divided by an insuperable barrier from all the lower animals in his mental faculties. I formerly made a collection of above a score of such aphorisms, but they are almost worthless, as their wide difference and number prove the difficulty, if not the impossibility, of the attempt. It has been asserted that man alone is capable of. progressive improvement ; that he alone makes use of tools or fire, domes- ticates other animals, or possesses property; that no animal has the power of abstraction, or of forming general concepts, is self-conscious and comprehends itself ; that no animal employs language ; that man alone has asense of beauty, is liable to caprice, has the feeling of gratitude, mystery, etc.; believes in God, or is endowed with a conscience. I will hazard a few remarks on the more important and interesting of these points. Archbishop Sumner formerly maintained * that man alone is capable of progressive improvement. ‘That he is capable of incomparably greater and more rapid improvement than is any other animal, admits of no dispute; and this is mainly due to his power of speaking and handing down his acquired knowledge. With animals, looking first to the individual, everyone who has had any experience in setting traps knows that young ani- mals can be caught much more easily than old ones; and they can be much more easily approached by an enemy. Even with respect to old animals, it is impossible to catch many in the same place and in the same kind of trap, or to destroy them by the same kind of poison; yet it is improbable that all should have partaken of the poison, and impossible that all should have been caught in a trap. They must learn caution by seeing their brethren caught or poisoned. In North America, where the fur- bearing animals have long been pursued, they exhibit, accord- ing to the unanimous testimony of all observers, an almost incredible amount of sagacity, caution, and cunning ; but trap- ping has been there so lung carried on, that inheritance may 80 See “Madness in Animals,” b 31, Quoted by Sir C. L oa of W. Lauder Lindsay, in “* Jo of mn M “ig eos ir aes Antiquity ” July, 187% an,” 96 THE DESCENT OF MAN. {PART & possibly have come into play. I have received several accounts that when telegraphs are first set up in any district, many birds kill themselves by flying against the wires, but that in the course of a very few years they learn to avoid this danger, by seeing, as it would appear, their comrades killed.” If we look to successive generations, or to the race, there is no doubt that birds and other animals gradually both acquire and lose caution in relation to man or other enemies ;* and this caution is certainly in chief part an inherited habit or instinct, but in part the result of individual experience. A good observer, Leroy,* states that in districts where foxes are much hunted, the young, on first leaving their burrows, are incontestably much more wary than the old ones in districts where they are not much disturbed. Our domestic dogs are descended from wolves and jackals,® and, though they may not have gained in cunning, and may have lost in wariness and suspicion, yet they have progressed in certain moral qualities, such as in affection, trust-worthiness, temper, and probably in general intelligence. ‘The common rat has conquered and beaten several other species throughout Europe, in parts of North America, New Zealand, and recently in Formosa, as well as on the mainland of China. Mr. Swinhoe,* who describes these two latter cases, attributes the victory of the common rat over the large Aus coninga to its superior cunning; and this latter quality may probably be attributed to the habitual exercise of all its faculties in avoid- ing extirpation by man, as well as to nearly all the less cunning or weak-minded rats having been continuously destroyed by him. It is, however, possible that the success of the common rat may be due to its having possessed greater cunning than its fellow-species, before it became associated with man. ‘To maintain, independently of any direct evidence, that no animal during the course of ages has progressed in intellect or other mental faculties, is to beg the question of the evolution of species. We have seen that, according to Lartet, existing mammals belonging to several orders have larger brains than their ancient tertiary prototypes. It has often been said that no animal uses any tool; but the $2 For additional evidence, with details, $4 “‘Tettres Phil. sur Pintelligence des see M. Houzeau, ‘‘ Les Facultés Mentales,” Animaux,” nouvelle édit., 1802, p. 86. tom. ii., 1872, p. 147. 35 See the evidence on this head in chap. 33 See, with respect to birds on oceanic i. vol. i., “On the Variation of Animals ang islands, my “ Journal of Researches during Plants under Domestication.” tne Voyage of the Beagle,” 1845, p, 398. 3¢ “ Proc. Zoolog. Soc.,” 1864, p. 186, “ Origin of Species,” sth edit., p. 260. Chae. iJ MENTAL POWFRS, 97 chimpanzee in a state of nature cracks a native fruit, some- what like a walnut, with a stone.” Rengger ® easily taught an American monkey thus to break open hard palm-nuts; and afterward, of its own accord, it used stones to open other kinds of nuts, as well as boxes. It thus.also removed the soft rind of fruit that had a disagreeable flavor. Another monkey was taught to open the lid of a large box with a stick, and after- ward it used the stick as a lever to move heavy bodies; and I have myself seen a young orang put a stick into a crevice, slip his hand to the other end, and use it in the proper manner as a lever. The tamed elephants in India are well known to break off branches of trees and use them to drive away the flies ; and this same act has been observed in an elephant in a state of nature.¥ I have seen a young orang, when she thought she was going to be whipped, cover and protect herself with a blanket or straw. In these several cases stones and sticks were em- ployed as implements ; but they are likewise used as weapons. Brehm states, on the authority of the well-known traveller, Schimper, that in Abyssinia when the baboons belonging to one species (C. ge/ada) descend in troops from the mountains to plunder the fields, they sometimes encounter troops of another species (C. hamadryas), and then a fight ensues. The Geladas roll down great stones, which the Hamadryas try to avoid, and then both species, making a great uproar, rush furiously against each other. Brehm, when accompanying the Duke of Coburg- Gotha, aided in an attack with fire-arms on a troop of baboons, in the pass of Mensa in Abyssinia. The baboons in return rolled so many stones down the mountain, some as large as aman’s head, that the attackers had to beat a hasty retreat, and the pass was actually closed for a time against the caravan. It deserves notice that these baboons thus acted in concert. Mr. Wallace“ on three occasions saw female orangs, accompanied by their young, ‘* breaking off branches and the great spiny fruit of the Durian tree, with every appearance of rage; causing sucha shower of missiles as effectually kept us from approaching too near the tree.’’ As I have repeatedly seen, a chimpanzee will throw any object at hand at a person who offends him ; and the before-mentioned baboon at the Cape of Good Hope prepared mad for the purpose. In the Zoological Gardens, a monkey, which had weak teeth, $7 Savage and Wyman in “Boston Jour: 8° The ‘‘ Indian Field,” ee 4) 187% tal of Nar. Hist.,” vol. iv., 1843-44, p. 383. 40 **Thierleben,” B. i. s. “ Sdugethiere von Paraguay,” 1830, s. 860. 7 Malay Dechigoaan” vol. the : 38 Dp. O7- : Ri Vok F 98 THE DESCENT OF MAN; (PART 4 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 ave 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 peculiar 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. Lub- bock’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 feshion them rudeiy. This lafter 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 oc- casionally flows through forests. The anthropomorphous apes, guided probably by instinct, build for themselves temporary platforms; but as many instincts are largely controlled by reason, the simpler ones, such as this of building a platform, might readily pass into a voluntary and conscious act. The orang is known to cover itself at night with the leaves of the Pandanus ; and Brehm states that one of his baboons used to protect itself from the heat of the sun by throwing a straw- mat over its head. In these several habits we probably see the first steps toward some of the simpler arts, such as rude ‘architecture and dress, as they arose among the early progeni- tors of man. - Abstraction, General Conceptions, Self-consciousness Mental Lndtviduality.—\t would be very difficult for anyone 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 _ 4&8 “Primeval Man,” 1869, pp. 145, 147 #2 « Prehistoric Times,” 1865, p- 473, ett CHAP. 1u.} MENTAL POWERS. e 3) 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 absenc¢ 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 «lear that he perceives that it is a dog 11 the abstract; for. when he gets nearer his whole manner suldenly changes, if the other dog be a friend. A recent writer 1emarks, 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 asin man. If 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 asign 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 neighbor- ing tree for a squirrel. Now do not these actions clearly show that she had in her mind a general idea or concept that some animal is to be discovered and hunter? 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 shown by his dreams, never reflects on his past pleasures or pains in the chase? And this would be a form of self-con- sciousness. On the other hand, as Biichner “ has remarked, how little can the hard-worked wife of a degraded Australian Savage, who uses very few abstract words, and cannot count above four, exert her self-consciousness, or reflect on the nature of her own existence. It is generally admitted that the higher atuimals possess memory, aitention, association, and even some imagination and reason. If these powers, which differ much in different animals, are capable of improvement, there seems no great improbability in more complex faculties, such as the higher forms of abstraction, and self-consciousness, etc., having been evolved through the development and combination of the simpler ones, It has been urged against the views here main- 44 Mr, Hookham, in a letter to Prof. Max #8 «* Conferences sur la Théorie Darwk ot in the “ Birmingham News,” May, nienne,” French translat., 1869, p. 138 Bo au THE DESCENT OF MAN, {PART & tained, that it is impossible to say at what point in the ascend- ing scale animals become capable of abstraction, etc. ; but who can say at what age this occurs in our young children? We see at least that such powers are developed in children by im- perceptible 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 for- ward the argument lately advanced to crush all evolutionists, and said, ‘I abide amid all mental moods and all material changes. . . . The teaching that atoms leave their impres- sions as legacies to other atoms falling into the places they have vacated is contradictory of the utterance of conscious- ness, and is therefore false; but it is the teaching necessi- tated by evolutionism, consequently the hypothesis is a false ane.’’46 Language.—This faculty has justly heen considered as one of the chief distinctions between man and che lower animals. But man, as ahighly competent judge, Archbishop Wakely remarks, is not the only animal that can make use of language to ex- press what is passing in his mind, and can understand, more or less, what is so expressed by another.’7 In Paraguay the Cebus azare when excited utters at least six distinct sounds, which excite in other monkeys similar emotions.“ ‘The move- ments of the features and gestures of monkeys are understood by us, and they partly understand ours, as Rengger and others declare. It is a more remarkable fact that the dog, since being domesticated, has learned to bark * in at least four or five dis- tinct 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, as when starting on a walk with his master; and the very distinct one of demand or supplication, as when wishing for a door or window to be opened. Ac- cording to Houzeau, who paid particular attention to the 48 The Rev. Dr. Re M’Cann, *“ Anti-Dar- 48 Rengger, ibid., s.45. winism,” 1869, p. 1 49 See my “Variation of Animals and 47 enais in ‘ : Acithropolopical Review,” Plants under Domestication,” vol. i. p. 29 3864, p. 158 cHAP, III] ‘MENTAL POWERS, EOs! subject; the domestic fowl utters at least a dozen significant sounds.” The habitual use of articulate language is, ftunistinen: peculiar to man; but he uses, in common with the lower animals, inar- ticulate’ 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 feelings, which are but little connected with our higher intelligence. Our cries of pain, fear, surprise, anger, together with their appropriate ac~ tions, 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 articu- late sounds, for, as everyone 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- etringly 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 sounds and ideas; and this obviously depends on the high develop- ment 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 learned. 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 90 “ Facultés Mentales des Antena’ pe ii., 1872, pp. 346-349. 1 See a discussion on this subject in Mr, E. "B. Tylor’s very interesting work, ‘* Re- searches into the Early History of Man- kind,” 1865, chaps. ii. to iv. ®2 ( have received several detailed - ac- sounts to this effect, Admiral Sir J. Sulli- van, whom [ know to be a careful observer, assures me that an African parrot, long kept in his father’s house, invariably called eer tain persons of the household, as well as vis- itors, by theirnames. He said “ Good morn: ing” to eVeryOne at breakfast, arid’ ‘Good night ” to each as they left the room at night, and never reversed these salutations. ‘Io Sir J. Sullivan’s father, he used to add to the ‘Good morning ” a short sentence, which was never once repeated after his father’s death, .He scolded. violently a strange dog which came into the room through the open window ; and he scolded another parrot (saying ‘f You naughty polly’) which°had got out of its cage, and was éating apples on the kitchen table. See also, to the same effect, Houzeau on parrots, **Facultés Mentales,’=tom. ii. p. 309. Dre Av’ Moschkau informs»me that he knew a strrling which never made a mistake in say- ing in German “f Good morning” to persons arriving. and: ‘“Good-by, iold fellow,” te those departing. 1 could add several other such cases,: 102 THE DESCENT OF MAN. (PART 1. young children; while no child has an instinctive tendency to brew, bake, or write. Moreover, no philologist now supposes that any language has been deliberately invented; it has been slowly and unconsciously developed by many steps. The sounds uttered by birds offer in several respects the nearest analogy to language, for all the members of the same species utter the same instinctive cries expressive of their emotions ; and all the kinds which sing, exert their power instinctively ; but the actual song, and even the call-notes, are learned from their parents or foster-parents. ‘These sounds, as Daines Bar- rington®™ has proved, ‘fare no more innate than language is in man.’’ ‘The first attempts to sing ‘‘ may be compared to the imperfect endeavor in a child to babble.’’ The young males continue practising, or as the bird-catchers say, ‘‘ record- ing,’’ 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 learned 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 in the same species inhabiting different districts may be appositely compared, as Barrington remarks, ‘‘ to provincial dialects,’’ and the songs of allied though distinct species may be com- pared with the languages of distinct races of man. I have - given the foregoing details to show 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. Hens- leigh Wedgwood, the Rev. F. Farrar, and Prof. Schleicher,® and the celebrated lectures of Prof. Max Miiller, 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 53 Sce some good remarks on this head by Prof. Whitney, in his ‘‘ Oriental and Lin- guistic Studies,” 1873, p. 354. He observes that the desire of communication between man is the living force, which, in the devel- opment of language, ‘‘ works both con- sciously and unconsciously ; consciously as regards the immediate end to be attained ; unconsciously as regards the further conse- quences of the act.” 54 Hon. Daines Barrington, in ‘* Philo- goph. Transactions,” 1773, p. 262. See also Dureau de la Malle, in ‘‘Ann. des. Sc. Nat.,” 3d series, Zoolog., tom, x. p. 119. 68 **On the Origin of language,” by H. Wedgwood, 1866. ‘‘ Chapters on Lan- guage,” by the Rev. F. W. Farrar, 1865. These works are most interesting. See also “De la Phys. et de Parole,” par Albert Le moine, 1865, p. 190. The workon this sub- ject, by the late Prof. Aug. Schleicher, has been translated by Dr. Bikkers into Eng- lish. under the title of “* Darwinism testea by the Science of Language,” 2869. CHAP. IIL} MENTAL POWERS. 103 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 expressive 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, intelligible 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 progenitor of man must have been more highly developed than in any existing ape, before even the most imperfect form of speech could have come into use; but we may confidently believe that the continued use and advancement of this power would have reacted on the mind itself, by enabling and encourag- ing 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 ordi- tary train of thought almost requires, or is greatly facilitated by, 5° Vogt, *‘Mémoire sur les Microcé- ghalles,* 1867, p. 169. With respect to savages, 1 have given some facts in my ** Journal of Researches,” etc., 1845, p. 87 See clear evidence on this head in the two works so often quoted, by Brehm and Rengger. 68 Ffouzeau gives a very curious account of his observations on this subject in hig **Facultés Mentales des Animaux,” tom ii. p. 348. [04 THE DESCENT OF MAN, {PART %, some form of language, for the dumb, deaf, and blind) gist, Laura Bridgman, was observed to use her fingers while dreams ing. 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 dur- ing theirdreams. We have, also, seen that animals are able to reason to a certain extent, manifestly without, the aid of lan- guage, The intimate connection between the brain, as it is now developed in us, and the faculty of speech, is well shown by those curious cases of brain disease in. which speech is specially affected, as when the power to remember substantives is. lost, while 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- ability in the continued use of the mental and vocal organs leading to inherited changes in their. structure and functions, than in the case of handwriting, which depends partly on the form of the hand and partly on the disposition of the mind ; and handwriting is certainly inherited.” 3 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 endeavored 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 connect certain sounds with certain general ideas as quickly as they do, unless ‘such 59 See remarks on this head by Dr. Maudsley, “‘The Physiology and Pathol- “ogy of Mind,” 2d edit., 1868, p. 199. 80 Many curious cases have been record- éd. See. for instance, Dr. Bateman “ On Aphasia,” 1870, pp. 27,/31, 535 100, etc. Also, ** Inquiries Concerning the Intellectual Powers,” by Dr. Abercrombie, 1838; p. 1so. $1 « The Variation of Animals and Plants under Domestication,” vol. ii. p. 6 62 Lectures on ‘ Mr. Darwin’s Pi lnc of Language,” 1873. 83 The cdot of a distinguished phi- lologist, such as Prof. Whitney, will have far more weight on this point than anything that Ican say. He remarks (‘‘ Oriental and Linguistic Studies,” 1873, P. 207), in speak- ing of Bleek’s views: ‘* Because on the and scale language is the’ necessary aux- tliary of thought, indispensable'to the devel- 9pment of the power of thinking, to the dis- tinctness and varie iol complexity of cognitions, to the full mastery of conscious- ness; therefore he would fain make thought absolutely impossible without speech, identi- fying the faculty with its instrument He mightjust as reasonably assert that the hu- man hand cannot act without a tool. With such a doctrine to start from, he cannot stop short of Miiller’s worst paradoxes, that an infant ‘(2a fans, not speaking) is not a hu- man being, and that deaf-mutes do ‘not be- come possessed of reason until they learn to twist ‘their fingers into imitation of spoken words.” Max Miiller gives in italics (‘* Lect- ures on Mr. Darwin’s Philosophy of Lan: guage,” 1873, third lecture) the following aphcrism: ‘‘ There is no. thought without words. as little as there are words. without thought.” What a strange definition musé here be given to the word thought! CHAP, ITT. MENTAL POWERS, . 10s ideas were aJready formed in their minds... The same .remark “may be extended to the more intelligent 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 philoso- pher. And the capacity, to understand is as-good a proof, of vocal intelligence, though in an inferior sie as the capacity to speak.”’ Why the organs. now used for speech. s10uld,.have. bees originally perfected for this, purpose, rather shan any. other or- gans, it is not difficult to see. Ants have considerable powers of intercommunication by means of their,antenne, as,shown by Huber, who devotes a whole chapter to. their language.;,.We “might have used our fingers..as. efficient instruments, for-a person with practice confessing that the happiness and misery of _.?4 ‘Mental and Moral Science,” 1868, pe others are not spectacles altogether indiffer- 254. , dae emt to us, but that the view of the former CHAP. IV.} MORAL SENSE, 125 Consequently 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 of his’ fellow-men, and, unfortunately, very often by his own 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 impellzd, apart from any transitory pieasure or pain, to certain lines of con- duct. He might then declare—not that any barbatian or un- cultivated man could thus think—I am the suprerue 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 theless persistent Instincts.—We have not, however, as yet cousiaered the main point on which, from our present point of view, the whole question of the moral sense turns. Why shouid a man feel that he ought to obey one instinctive desire racher than another? Why is he bitterly regretful, if he has yielded to a strong sense of self-preservation, and has not risked ‘ris life to save that of a fellow-creature ? or why does he regre. having stolen food from hunger ? | It is evident, in the first place, that with mankind the instinc- tive impulses have different degrecs of strength; a savage will risk his own life to save that of a member of the same com- munity, 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 mre 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 dis- regarded 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 Arnerican 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 ins 126 THE DESCENT OF MAN. {PART L stantaneously 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 moral. They confine this term to actions done deliberately, after a victory over opposing desires, or when prompted by some exalted motive. But it appears scarcely possible to draw any clear line of distinction of this kind.* As far as exalted motives are con- cerned, many instances have been recorded of savages, destitute of any feeling of general benevolence toward 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 qualities are innate. He who is forced to overcome his fear or want of sympathy before he acts, deserves, however, in one way higher credit than the man whose innate disposition leads him to a good act without effort... As we cannot distinguish between motives, we rank all actions of a certain class as moral, if per- formed by amoral being. A moral being is one who is capa- ble of comparing his past and future actions or motives, and of 2° T refer here to the distinction between what has been called #zaterzaland formal morality. I am glad to find that Prof. Hux- ley (“Critiques and Addresses,’’ 1873, p. 287) takes the same view on this subject as Ido. Mr. Leslie Stephen remarks (‘* Es- says on Freethinking and Plain Speaking,” 3873, P- 83), “‘ the metaphysical distinchon between material and formal morality is as irrelevant as other such distinctions.” 28 | have given one such case, namely, of three Patagonian Indians who preferred be- ing shot, one after the other, to betraying the plans of their companions in waft (** Journal of Researches,” 1845, p. 103} CHAP. {V.]_ MORAL SENSE, BaRez approving or disapproving of them. We have no reason to suppose that any of the lower animals have this capacity ; therefore, when a Newfoundland dog drags a child out of the water, or a monkey faces danger to rescue its comrade, or takes charge of an orphan monkey, we do not call its conduct moral. But in the case of man, who alone can with certainty be ranked as a moral being, actions of a certain class are called moral, whether performed deliberately, after a struggle with opposing motives, or impulsively through instinct, or from the 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 corresponding actions, yet it is untenable that in man the so- cial 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, etc. Why then does man regret, even though trying to banish such regret, that he has followed the one natu- tal impulse rather than the other; and why does he further feel that he ought to regret his conduct ? Man in this respect differs profoundly from the lower animals. Nevertheless we can, I think, see with some degree of clearness the reason of this difference. Man, from the activity of his mental faculties, cannot avoid reflection ; past impressions and images are incessantly and clearly passing through his mind. Now with those animals which live permanently in a body, the social instincts are ever present and persistent. Such animals are always ready to utter the 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 desire, some degree of love and sympathy for them ; they are unhappy if long separated from them, and always happy to be again in their company. So it is with ourselves. Even when we are quite alone, how often do we think with pleasure or pain of what others think of us—of their imagined approbation or dis- approbation ; and this all follows from sympathy, a fundamen- tal element of the social instincts. A man who possessed no trace of such instincts would be an unnatural monster. On the other hand, the desire to satisfy hunger, or any passion such as vengeance, is in its nature temporary, and can for a time be fully satisfied. Nor is it easy, perhaps hardly possible, to call up with complete vividness the feeling, for instance, of hunger 5 128 THE DESCENT OP MAN, (PARTE nor indeed, as has often been remarked, of any suffering... The instinct of self-preservation is not felt excey»t in the presence of danger ;, and many a coward has thought himself brave vuntil -he has met his enemy face to face. The wish for another man’s property is perhaps as persistent a desire as any that ¢an 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 an habitual one, after success has wondered why he stole some article.” | A man cannot prevent past impressions often repassing ihrough his mind ; he will thus be driven to make a compari- son between the impressions of past hunger, vengeance satisfied, or dangez 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 blamable.. This knowledge cannot be banished from his mind, and from in- stinctive sympathy is esteemed of great moment. He will then feel as if he had been balked in following a present in- stinct or habit, and this with all aniinals causes dissatisfaction, or even misery. The above case of the swallow affords an illustration, though of a reversed nature, of a temporary, though for the time stronglv persistent, instinct conquering another instinct which is usually dominant over all others. At the proper season these birds seem all day long to be impressed with the desire _to migrate; their habits change; they become restless, are noisy, and congregate in flocks. While 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 persistent gains the victory, and at last, at a moment, when her young ones are not in sight, she ‘takes flight and deserts them. When arrived at the end of her:long jour- 37 Enmity or hatred seems also to be a highly persistent feeling, perhaps more so “than any other that can be named. Envy is defined as hatred of another for some excel- lence or success ; and Bacon insists (Essay ix.), ‘‘ Of all other affections envy is the most importune and continual.” Dogs are very apt to hate both strange men and strange dogs, especially if they live near at hand, but do not belong to the same family, tribe, or clan; this feeling would thus seem to be innate, and is certainly a most persist- ent one, It seems to be the complement and converse of the true social instinct.” From what we hear of savages, it would appear that something of the same kind holds geod _ with them. If this be so, it would be a “small step in any one to transfer such feel- ings to any member of the same tribe if he had done him an injury and had become his enemy. Nor is it probable that the primi- tive conscience would reproacha man for in- juring his enemy: rather it would reproach him if he had not revenged himself, . To-do good in return for evil, to love your enemy, is a height of morality to which it may be doubted whether the social instincts would, by themselves, have ever led us. It is nec- essary that these imstincts,, ether with sympathy. should have been highly culti- vated and extended by the aid of reason, instruction, and the love or fear of God, be- fore any such golden rule would ever be theught of and obeyed. — Ww at so CHAP. IV.] MORAL SENSE. 1290 ney, 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 colistantly passing through her mind, of her young ones perish- ing in the bleak north from cold and hunger. _ At the moment of action man will no doubt be apt to fol- low. 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, re- gret, or shame; this latter feeling, however, relates almost. ex- clusively. to the judgment of others. He will consequently re- solve more or less firmly to act differently for the future; and this is consci nce; for conscience looks backward, 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 cur 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 re- mote consequences of his acts. Another element is ‘most im- portant, although not necessary—the reverence or. fear of thé Gods or Spirits believed in by each man; and this applies especially in cases of remorse. Several critics have objected that, though some slight regret or repentance may be explained by the yiew advocated in this chapter, it is impossible thus to.ac- count for the soul-shaking feeling of remorse. . But I can see lit- tle force in this objection. My critics do not define what they mean by remorse, and I can find no definition implying more than an overwhelming sense of repentance. . Remorse seems to bear the same relation to repentance as rage does to anger, or agony to pain. It is far from strange that an instinct so strong and so generally admired as maternal love should, if dis- obeyed, lead to the deepest misery, as. soon as the impression of the past cause of disobedience is weakened. _ Even when an action is opposed to no special instinct, merely to know that our friends and equals despise us for it is enough to cause great misery. Who can doubt that the refusal to fight a, duel 430 THE DESCENT OF SIAN. (PART 3 through fear has caused many men an agony of shame? Many a Hindoo, it is said, has been stirred to the bottom of his soul by having partaken of unclean food. Here is another case of what must, I think, be called remorse. Dr. Landor acted as a magistrate in West Australia, and relates * that a native on his farm, after losing one of his wives from disease, came and - 3aid that ‘‘ he was going to a distant tribe to spear a woman, to satisfy his sense of duty to his wife. I told him that if he did so, I would send him to prison for life. le remained about the farm for some months, but got exceedingly thin, and complained that he could not rest or eat, that his wife’s spirit was haunting him, because he had not taken a life for hers. I was inexorable, and assured him that nothing should save him if he did.’’ Nevertheless the man disappeared for more than a year, and then returned in high condition; and his other wife told Dr. Landor that her husband had taken the life of a woman belonging to a distant tribe; but it was im- possible to obtain legal evidence of the act. The breach of a rule held sacred by the tribe will thus, as it seems, give rise to the deepest feelings—and this quite apart from the social instincts, excepting in so far as the rule is grounded on the judgment of the community. How so many strange supersti- tions have arisen throughout the world we know not; nor can we tell how some real and great crimes, such as incest, have come to be held in an abhorrence (which is not however quite universal) by the lowest savages. It is even doubtful whether in some tribes incest would be looked on with greater horror than would the marriage of a man with a woman bearing the same name, though not arelation. ‘‘ 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 killa girl of a foreign tribe or to marry a girl of one’s own, an an- swer just opposite to ours would be given without hesitation.’’ We may, therefore, reject the belief, lately insisted on by some writers, that the abhorrence of incest is due to our possessing : special God-implanted conscience. On the whole it is in- telligible that a man urged by so powerful a sentiment as re- morse, 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. 38 “Insanity in Relation to Law;” On- °F. B. Tylor in “Contemporary Rae gario, United States, 1871, p. 14. view,” April, 1873, p. 707+ m —)— CHAP, IV. MORAL SENSE, 138 Man, prompted by his conscience, will through long habit acquire such perfect self-command, that his desires and passions will at Jast yield instantly and without a struggle to his social sympathies and instincts, including his feeling for the judgment of his fellows. ‘The still hungry or the still revengeful man will not think of stealing food or of wreaking his vengeance. It is possible, or, as we shall hereafter see, even probable, that the habit of self-command may, like other habits, be inherited. Thus at last man comes to feel, through acquired and perhaps inherited habit, that it is best for him to obey his more per- sistent impulses. The imperious word ought seems merely to imply the consciousness of the existence of a rule of conduct, however it may have originated. Formerly it must have been often vehemently urged that an insulted gentleman ought to fight a duel. We even say that a pointer ough? 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 realized. If he has no such sympathy, and if his desires leading to bad actions are at the time strong, and when recalled are not overmastered by the persistent social instincts and the judgment of others, then he is essentially a bad man ;* and the sole restraining motive left is the fear of punisnment, 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 everyone may with an easy conscience gratify his own desires, if they do not interfere with his social instincts, that is with the good of others ; but in order to be quite free from self-reproach, or at least of anxiety, it is almost necessary for him to avoid the disapprobation, whether reason- able 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 likewise avoid the reprobation of the one God or gods 80 Dr. Prosper Despine, in his “‘ Psychol- worst criminals, who apparently have heen ogie Naturelle,” 1823 (tom. i. p. 243; tom. entirely destitute of conscience, Pp. 169) gives many curious cases of the . &32 THE DESCENT OF MAN, {PART L. in whom, according to his knowledge or superstition, he may believe ; but in this case the additional fear of divine geo ment often supervenes. Lhe strictly Social Virtues at first alone regarded. The above view of the origin and nature of the moral sense, which tells us what we ought to do, and of the conscience which re- proves us if we disobey it, accords well with what we see of the early and undeveloped condition of this faculty in man- kind. ‘The virtues which must be practised, at least generally, by rude men, so that they may associate in a body, are those which are still recognized as the most important. But they are practised almost exclusively in relation to the men of the same tribe ; and their opposites are not regarded as crimes in relation to the men of othex tribes. No tribe could hold together if murder, robbery, treachery, etc., were common; consequently such crimes within the limits of the same tribe “ are branded with everlasting infamy ;’’ *! but excite no such sentiment be- yond these limits. A North American Indian is well pleased with himself, and is honored ‘by others, when he scalps a man of another tribe; and a Dyak cuts off the head of an unoffend- ing person, and dries it as a trophy. The murder of infants has prevailed on the largest scale throughout the world,® and has met with no reproach 3 but infanticide, especially of fe- males, has been thought to be good for the tribe, or at least not injurious. Suicide during former times was not generally con- sidered as a crime,® but rather, from the courage displayed, as an honorable act; and it is still practised by some semi-civil- ized and savage nations without reproach, for it does not ob- viously concern others of the tribe. It has been recorded that an Indian Thug ‘conscientiously regretted that he had ‘not robbed and strangled as many travellers as did his father before him. In arude state of civilization the robbery of strangers is, indeed, generally considered as honorable. Slavery, although in some ways beneficial during ancient 31 See an able article in the “‘ North nee Review,” 1867, p. 395- See also Mr. Bagehot’s articles on the Importance “e Obedience and Coherence to area Suicide in Lecky’s ‘‘ History of European Morals,” vol. i., 1869, p. 223. With respect to savages, Mr. Winwood Reade inferms me that the negroes of West Africa ofien commit suicide. Itis well known how com- Man, in the “ Fortnightly Review,” 1867, p 529, and 1868, p. 457, etc. 2 The fullest account which I have met with is by Dr. Gerland, in his ‘‘ Ueber das Aussterben der Naturvilker,” 1868 ; but I shall have to recur to the subject of infanti- eide in a future chapter. $$ See the geo interesting discussion on mon it was among the miserable aborigines of South America, after the Spanish con- quest. For New Zealand, see the voyage of the Novara, and for the Aleutian Islands, Miiller, as quoted by Houzeau, “* Les Facultés Mentales,” etc., tom. ii. p. 336, cnAp. 1v.] MORAL SENSE. 133 times, is a great crime ; yet it was not so regarded until quite recently, even by the most civilized nations. And this was especially the case, because the slaves belonged in general to a race different from that of their masters. As barbarians do not regard the opinion of their women, wives are commonly treated like slaves. Most savages are utterly indifferent to the suffer- ings of strangers, or even delight in witnessing them. It is well known that the women and children of the North American Indians aided in torturing their enemies. Some savages take a horrid pleasure in cruelty to animals,® and humanity is an unknown virtue. Nevertheless, besides the family affections, kindness is common, especially during sickness, between the members of the same tribe, and is sometimes extended beyond these limits. Mungo Park’s touching account of the. kindness of the negro women of the interior to him is well known. Many instances could be given of the noble fidelity of savages toward each other, but not to strangers ; common experience justifies the maxim of the Spaniard, ‘‘ Never, never trust an Indian.’’ There cannot be fidelity without truth ; and this fundamental virtue is not rare between the members of the same tribe: thus Mungo Park heard the negro women teacning their young children to love the truth. This, again, is one of the virtues which becomes so deeply rooted in the mind that it is sometimes practised by savages, even at a high cost; toward strangers; but to lie to your enemy has rarely been thought a sin, as the history of modern diplomacy too piainiy shows. As soon as a tribe has a recognized leader, disobedi- ence becomes a crime, and even abject submission is looked at as a sacred virtue. As during rude times no man can be useful or faithful to his tribe without courage, this quality has universally been placed in the highest rank ; and although in civilized countries a good yet timid man may be far more useful to the community than a brave one, we cannot help instinctively honoring the latter above a coward, however benevolent. Prudence, on the other hand, which does not concern the welfare of others, though a very useful virtue, has never been highly esteemed. As no man can practise the virtues necessary for the welfare of his tribe without self-sacrifice, self-command, and the power of endurance, these qualities have been at all times highly and 84 See Mr. Bagehot, “‘ Physics and Poli- count of the Kaffirs, ‘‘ Anthropylogica) tics,” 1872, p. 72+ : Review,” 1870, p. xv. 86 See, for instance, Mr. Hamilton’s ac- 134 THE DESCENT OF MAN. {PA2? + 4 most justly valued. The American savage voluntarily submits to the most horrid tortures without a groan, to prove and strengthen his fortitude and courage; and we cannot help admiring him, or even an Indian Fakir, who, from a foolish religious motive, swings suspended by a hook buried in ln. flesh. The other so-called self-regarding virtues, which do not ob- viously, though they may really, affect the welfare of the tribe, have never been esteemed by savages, though now highly appreciated by civilized nations. ‘The greatest intemperance is no reproach with savages. . Utter licentiousness and un- natural crimes prevail to an astounding extent. As soon, however, as marriage, whether polygamous or monogamous, becomes common, jealousy will lead to the inculcation of female virtue ; and this, being honored, will tend to spread to the un- married females. How slowly it spreads to the male sex, we see at the present day. Chastity eminently requires self-com- mand ; therefore it has been honored from a very early period in the moral history of civilized man. As a consequence of this, the senseless practice of celibacy has been ranked from a remote period as a virtue.’ The hatred of indecency, which appears to us so natural as to be thought innate, and which is so valuable an aid to chastity, is a modern virtue, appertaining exclusively, as Sir G. Staunton remarks,*® to civilized life. This is shown by the ancient religious rites of various nations, by the drawings on the walls of Pompeii, and by the practices of many Savages. We have now seen that actions are regarded by savages, and were probably so regarded by primeval man, as good or bad, solely as they obviously affect the welfare of the tribe—not that of the species, nor that of an individual member of the tribe. This conclusion agrees well with the belief that the so-called moral sense is aboriginally derived from the social instincts, for both relate at first exclusively to the community. The chief causes of the low morality of savages, as judged by our stand- ard, are, firstly, the confinement of sympathy to the same tribe. Secondly, powers of reasoning insufficient to recognize the bearing of many virtues, especially of the self-regarding virtues, on the general welfare of the tribe. Savages, for in- stance, fail to trace the multiplied evils consequent on a want 86 Mr. M‘Lennan has given (‘Primitive 87 Lecky, ‘* History of European Morals,® Marriage,” 1865, p. 176) a good collection of vol. i., 1869, p. 109. . | : facts on this head. #5 “« Embassy to China,” vol. il. p 348, ——— cc CHAP. iVv.] MORAL SENSE 535 of temperance, chastity, etc. And, thirdly, weak power of selfcommand; for this power has not been strengthened through long-continued, perhaps inherited, habit, instruction, and religion. I have entered into the above details on the immorality of savages, because some authors have recently taken a high view of their moral nature, or have attributed most of their crimes to mistaken benevolence.” These authors appear to rest their conclusion on savages possessing those virtues which are serviceable, or even necessary, for the existence of the family and of the tribe—qualities which they undoubtedly do possess, and often in a high degree. Concluding Remarks.—It was assumed formerly by philos- ophers of the derivative “ school of morals that the foundation of morality lay in a form of Selfishness ; but more recently the ‘«¢ Greatest happiness principle’’ has been brought prominently forward. It is, however, more correct to speak of the latter principle as the standard, and not as the motive of conduct. Nevertheless, all the authors whose works I have consulted, with a few exceptions,” write as if there must bea distinct motive for every action, and that this must be associated with some pleasure or displeasure. But man seems often to act im- pulsively, that is from instinct or long habit, without any con- sciousness of pleasure, in the same manner as does probably a bee or ant, when it blindly follows its instincts. Under cir- cumstances of extreme peril, as during a fire, when a man en- deavors to save a fellow-creature without a moment’s hesitation, he can hardly feel pleasure ; and still less has he time to reflect on the dissatisfaction which he might subsequently experience if he did not make the attempt. Should he afterward reflect over his own conduct, he would feel that there lies within him 39 See on this subject copious evidence in Chap. vii. of Sir J. Lubbock, ** Origin of Civilization,” 1870. 49 For instance, Lecky, ‘* History of Euro- pean Morals,” vol. i. p. 124. *) This term is used in an able article in the ‘‘ Westminster Review,” Oct , 1869, p. 498. For the ‘‘ Greatest happiness Beas: see J. S. Mill, “* Utilitarianism,” p. 17 42 Mill recognizes (‘* System of Logic,” vol. ii. p. 422) in the clearest manner, that actions may be performed throngh habit without the anticipation of pleasure. Mr. H. Sidgwick also, in his Essay on Pleasure and Desire (‘The Contemporary Review,” April, 1872, p. 671), remarks: ‘‘ To sum up, in contravention of the doctrine that our con- scious active impulses are always directed toward the production of agreeable sensa- tions in ourselves, I would maintain that we find everywhere in consciousness extra-re- garding impulse, directed toward something that is not pleasure ; that in many cases the impulse is so far incompatible with the self- regarding that the two do not easily co exist in the same moment of consciousness.” A dim feeling that our impulses do not by any means always arise from any contempora- neous or anticipated pleasure, has, I cannot but think, been one chief cause of the ac- ceptance of the intuitive theory of morality, and of the rejection of the utilitarian or ‘* Greatest happiness’’ theory. With respect to the latter theory, the standard and the motive of conduct have no doubt often been confused, but they are really in some degree blended. 136 THE DESCENT OF MAN. [PART §, an impulsive power widely different from a search after pleas- ure or happiness; and this seems to be the deeply planted social instinct. In the case of the lower animals it seems much more appro- priate to speak of their social instincts as having been de- veloped for the general good rather than for the general hap- piness of the species. The term, general good, may be defined as the rearing of the greatest number of individuals in full vigor and health, with all their faculties perfect, under the conditions to which they are subjected. As the social instincts both of man and the lower animals have no doubt been developed by - nearly the same steps, it would be advisable, if found practi- cable, to use the same definition in both cases, and to take as the standard of morality the general good or welfare of the community, rather than the general happiness ; but this defini- tion would perhaps require some limitation on account of polit- ical ethics. When a man risks his life to save that of a fellow-creature, it seems also more correct to say that he acts for the general good, rather than for the general happiness of mankind. No doubt the welfare and the happiness of the individual usually coincide ; and a contented, happy tribe will flourish better than one that is discontented and unhappy. We have seen that, even at an early period in the history of man, the expressed wishes of the community will have naturally influenced to a large extent the conduct of each member; and as all wish for happiness, the ‘« Greatest happiness principle ’’ will have become a most im- portant secondary guide and object; the social instinct, how- ever, together with sympathy (which leads to our regarding the approbation and disapprobation of others), having served as the primary impulse and guide. Thus the reproach is re- moved of laying the foundation of the noblest part of our nature in the base principle of selfishness; unless, indeed, the satisfaction which every animal feels, when it follows its proper instincts, and the dissatisfaction felt when prevented, be called selfish. The wishes and opinions of the members of the same com- munity, expressed at first orally, but later by wviting also, either form the sole guides of our conduct or greatly reinforce the social instincts; such opinions, however, have sometimes a tendency directly opposed to these instincts. This latter fact is well exemplified by the Zaw of Honor, that is, the law ef the opinion of our equals, and not of all our countrymen. 4 ‘ eHAP. 1V.] MORAL SENSE. 137 The breach of this law, even when the breach is known to be strictly accordant with true morality, has caused many a man more agony than a real crime. We recognize the same influ- ence in the burning sense of shame which most of us have felt, even after the interval of years, when calling to mind some accidental breach of a trifling, though fixed, rule of etiquette. The judgment of the community will generally be guided by some rude experience of what is best in the long run for all the members ; but this judgment will not rarely err from ignorance and weak powers of reasoning. Hence the strangest customs and superstitions, in complete opposition to the true welfare and happiness of mankind, have become all-powerful through- out the world. We see this in the horror felt by a Hindoo who breaks his caste, and in many other such cases. It would be difficult to distinguish between the remorse felt by a Hindoo who has yielded to the temptation of eating unclean food, from that felt after committing a theft; but the former would prop- ably be the more severe. How so many absurd rules of conduct, as well as so many absurd religious beliefs, have originated, we do not know ; nor how it is that they have become, in all quarters of the world, so deeply impressed on the mind of men; but it is worthy of _Yemark that a belief constantiy inculcated during the early years of life, while the brain is impressible, appears to acquire almost the nature of an instinct; and the very essence of an instinct is that it is followed independently of reason. Neither can we say why certain admirable virtues, such as the love of truth, are much more highly appreciated by some savage tribes than by others;* nor, again, why similar differences prevail even among highly civilized nations. Knowing how firmly fixed many strange customs and superstitions have become, we need feel no surprise that the seif-regarding virtues, supported as they are by reason, should now appear to us so natural as to be thought innate, although they were not valued by man in his early condition. Notwithstanding many sources of doubt, man can generally and readily distinguish between the higher and lower moral rules. The higher are founded on the social instincts, and re- late to the welfare of others. They are supported by the ap- probation of our fellow-men and by reason. The lower rules, thouga some of them when implying self-sacrifice hardly de- #3 Good instances are given by Mr. Wal- and more fully in his “ Contributions to the lace in ** Scientific Opinion,” Sept. 15, 1869; ‘Theory of Natural Selection,” 1870, p- 353¢ ¥35 THE DESCENT OF MAN. [PART £ / serve to be called lower, relate chiefly to self, and arise from public opinion, matured by experience and cultivation ; for they are not practised by rude tribes. As man advances in civilization, and small tribes are united into larger communities, the simplest reason would tell each individual that he ought to extend his social instincts and sympathies to all the members of the same nation, though per- sonally unknown to him. This point being once reached, there is only an artificial barrier to prevent his sympathies ex- tending to the men of all nations and races. If, indeed, such men are separated from him by great differences in appearance or habits, experience unfortunately shows us how long ‘t is before we look at them as our fellow-creatures. Sympathy beyond the confines of man, that is, humanity to the lower animals, seems to be one of the latest moral acquisitions. It is apparently unfelt by savages, except toward their pets. How little the old Romans knew of it is shown by their abhorrent gladiatorial exhibitions. The very idea of humanity, as far as I could observe, was new to most of the Gauchos of the Pam- pas. This virtue, one of the noblest with which man is en- dowed, seems to arise incidentally from our sympathies becom- ing more tender and more widely diffused, until they are extended to all sentient beings. As soon as this virtue is honored and practised by some few men, it spreads through instruction and example to the young, and eventually becomes incorporated in public opinion. The highest possible stage in moral culture is when we rec- ognize that we ought to control our thoughts, and ‘‘ not even in inmost thought to think again the sins that made the past so pleasant to us.’’ # Whatever makes any bad action familiar to the mind, renders its performance by so much the easier. As Marcus Aurelius long ago said, ‘‘Such as are thy habitual thoughts, s such also will be the character of thy mind ; for the soul is dyed by the thoughts.’’ ® Our great philosopher, Herbert Spencer, has recently ex- plained his views on-the moral sense. He says,* ‘‘1 believe that the experiences of utility, organized and consolidated through all past generations of the human race, have been pro- ducing corresponding modifications, which, by continued transmission and accumulation, have become in us certain fa/ 44 Tennyson, ‘‘Idylls of the King,” p. edit., 1869, p. 112. Marcus Aurelius wa 244. born A.D. 121. 46 ‘The Thoughts of the Emperor M. ‘4° Letter to Mr. Mill in Bain’s “ Ment Aurelius Antoninus,’? Eng, translat., 2d and Moral Science,’’ 1868, p. 722. ‘ 4 a CHAP. tV.} MORA™ SENSE .. [39 ulties of moral intuition—certain emotions responding to right and wrong conduct, which have no apparent basis in the in- dividual experiences of utility.’’ There is not the least inherent improbability, as it seems to me, in virtuous tendencies being more or less strongly inherited ; for, not to mention the vari- ous dispositions and habits transmitted by many of our domes- tic animals to their offspring, I have heard of authentic cases in which a desire to steal and a tendency to lie appeared to run in families of the upper ranks; and as stealing is a rare crime in the wealthy classes, we can hardly account by acci- dental coincidence for the tendency occurring in two or three members of the same family. If bad tendencies are transmitted, it is probable that good ones are likewise transmitted. That the state of the body, by affecting the brain, has great influence on the moral tendencies, is known to most of those who have suf: fered from chronic derangements of the digestion or liver. The same fact is likewise shown by the ‘*‘ perversion or destruc- tion of the moral sense being often one of the earliest symp. toms of mental derangement ;’’ “ and insanity is notoriously often inherited. Except through the principle of the trans- mission of moral tendencies, we cannot understand the differ- ences believed to exist in this respect between the various races of mankind. Even the partial transmission of virtuous tendencies would be an immense assistance to the primary impulse derived di- rectly and indirectly from the social instincts. Admitting for a moment that virtuous tendencies are inherited, it appears probable, at least in such cases as chastity, temperance, human- ity to animals, etc., that they become first impressed on the mental organization through habit, instruction, and example, continued during several generations in the same family, and in a quite subordinate degree, or not at all, by the individuals possessing such virtues having succeeded best in the struggle for life. My chief source of doubt with respect to any such inheritance is that senseless customs, superstitions, and _ tastes, such as the horror of a Hindoo for unclean food, ought on the same principle to be transmitted. I have not met with any evidence in support of the transmission of superstitious customs or senseless habits, although in itself it is perhaps not less prob- able than that animals should acquire inherited tastes for cer- tain kinds of food or fear of certain foes. #? Maudsley, “‘ Body and Mind,” 1890, p. 60 140 THE DESCENT OF MAN (PART L Finally the social instincts, which no doubt were acquired © by man as by the lower animals for the good of the commu- nity, will from the first have given to him some wish to aid his fellows, some feeling of sympathy, and have compelled him to regard their approbation and disapprobation. Such impulses will have served him at a very early period as a rude rule of right and wrong. But as man gradually advanced in intellect- ual power, and was enabled to trace the more remote conse- quences of his actions ; as he acquired sufficient knowledge to reject baneful customs and superstitions ; as he regarded more and more not only the welfare, but the happiness of his fel- low-men ; as from habit, following on beneficial experience, instruction, and example, his sympathies became more tender and widely diffused, extending to men of all races, to the imbecile, maimed, and other useless members of society, and finally to the lower animals—so would the standard of his morality rise higher and higher. And it is admitted by moral- ists of the derivative school, and by some intuitionists, that the standard of morality has risen since an early period in the history of man.® As a struggle may sometimes be seen going on between the various instincts of the lower animals, it is not surprising that there should be a struggle in man between his social instincts, with their derived virtues, and his lower, though momentarily stronger, impulses or desires. ‘This, as Mr. Galton® has re- marked, is all the less surprising, as man has emerged from a state of barbarism within a comparatively recent period. After having yielded to some temptation we feel a sense of dissatis- - faction, shame, repentance, or remorse analogous to the feelings caused by other powerful instincts or desires, when left unsatis- fied or balked. We compare the weakened impression of a past temptation with the ever-present social instincts, or with habits gained in early youth and strengthened during our whole lives, until they have become almost as strong as instincts. If with the temptation still before us we do not yield, it is because either the social instinct or some custom is at ‘the moment predominant, or because we have learned that it will appear to us hereafter the stronger, when compared with the 48 A writer in the “North British Review” 49 See his remarkable work on “ Heredi- July, 1860, p. 531), well capable of forming tary Genius,” 1869, p. 349. The Duke of 2 sound judgment, expresses himself strong- Argyll (‘‘ Primeval Man,” 1869, p. 188) has ty in favor of this conclusion. Mr. Lecky some good remarks on the contest in man’s ( “ Hist. of Morals,” vol. i. p- 143) seems to nature between right and wrong. Scertain e: tent to coincide therein. : | CHAP. 1V.} SUMMARY, 147 weakened impression of the temptation, and we realize that its violation would cause us suffering. Looking to future genera- tions, there is no cause to fear that the social instincts will grow weaker, and we may expect that virtuous habits will grow stronger, becoming perhaps fixed by inheritance. In this case the struggle between our higher and lower impulses will be less severe, and virtue will be triumphant. Summary of the last Two Chapters.—There can be no doubt that the difference between the mind of the lowest man and that of the highest animal is immense. An anthropomorphous ape, if he could take a dispassionate view of his own case, would admit that, though he could form an artful plan to plunder a garden—though he could use stones for fighting or for break- ing open nuts—yet that the thought of fashioning a stone into a tool was quite beyond his scope. | Still less, as he would ad- mit, could he follow out a train of metaphysical reasoning, or solve a mathematical problem, or reflect on God, or admire a grand natural scene. Some apes, however, would probably declare that they could and did admire the beauty of the col- ored skin and fur of their partnersin marriage. They would admit that, though they could make other apes understand by cries some of their perceptions and simpler wants, the notion of expressing definite ideas by definite sounds had never crossed their minds. ‘They might insist that they were ready to aid their fellow-apes of the same troop in many ways, to risk their lives for them, and to take charge of their orphans ; but they would be forced to acknowledge that disinterested love for all fiving creatures, the most noble attribute of man, was quite beyond their comprehension. Nevertheless the difference in mind between man and the higher animals, great as it is, certainly is one of degree and not of kind. We haveseen that the senses and intuitions, the various emotions and faculties, such as love, memory, attention, curiosity, imitation, reason, etc., of which man boasts, may be found in an incipient, or even sometimes in a well-developed condition, in the lower animals. ‘They are also capable of some inherited improvement, as we see in the domestic dog compared with the wolf or jackal. If it could be proved that certain high mental powers, such as the formation of general concepts, self-consciousness, etc., were absolutely peculiar to man, which seems extremely doubtful, it is not improbable that these qualities are merely the incidental results of other highly advanced intellectual faculties ; and these again mainly 742 THE DESCENT OF MAN. trArt iL the result of the continued use of a perfect language. At what age does the new-born infant possess the power of abstraction, : or become self-conscious, and reflect on its own existence ? | We cannot answer ; nor can we answer in regard to the ascend- ing organic scale. ‘The half-art, half-instinct of language still — bears the stamp of its gradual evolution. The ennobling belief in God is not universal with man ; and the belief in spiritual agencies naturally follows from other mental powers. ‘The moral sense perhaps affords the best and highest distinction between man and the lower animals ; but I need say nothing on this head, as I have so lately endeavored to show that the social instincts —the prime principle of man’s moral constitution "—with the aid of active intellectual powers and the effects of habit, natu- rally lead to the golden rule, ‘‘ As ye would that men should do to you, do ye to them likewise ;’’ and this lies at the founda- tion of morality. In the next chapter I shall make some few remarks on the probable steps and means by which the several mental and moral faculties of man have been gradually evolved. ‘That such evolution is at least possible, ought not to be denied, for we daily see these faculties developing in every infant ; and we may trace a perfect gradation from the mind of an utter idiot, lower than that of an animal low i in the scale, to the mind of 2 Newton. CHAPTER V. ON THE DEVELOPMENT OF THE INTELLECTUAL AND MORAL FACULTIES DURING PRIMEVAL AND CIVILIZED TIMES. Advancement of the intellectual powers through natural seleccion—Im- portance of imitation—Social and moral faculties—Their development within the limits of the same tribe—Natural selection as affecting civil- ized nations—Evidence that civilized nations were once barbarous, THE subjects to be disctissed in this chapter are of the highest ite but are treated by me in an imperfect and fragmen- tary manner. Mr. Wallace, in an admirable paper before re- ferred to,! argues that man, after he had partially acquired those intellectual and moral faculties which distinguish him from the lower animals, would have been but little liable to 50 «« The Thoughts of Marcus Aurelius, 7 1 Anthropological Review,” May, 1864, Ste.y Ps 139 p. clviii. selec ; CHAP. V.] INTELLECTUAL FACULTIES. 143 bodily modifications through natural selection or any other means. For man is enabled through his mental faculties ‘‘ to keep with an unchanged body in harmony with the changing universe.’’ He has great power of adapting his habits to new conditions of life. He invents weapons, tools, and various stratagems to procure food and to defend himself. When he migrates into a colder climate he uses clothes, builds sheds, and makes fires; and by the aid of fire cooks food otherwise indigestible. He aids his fellow-men in many ways, and an- ticipates future events. Even at a remote period he practised some division of labor. The lower animals, on the other hand, must have their bod- ily structure modified in order to survive under greatly changed conditions. They must be rendered stronger, or acquire more effective teeth or claws, for defence against new enemies; or they must be reduced in size, so as to escape detection and danger. When they migrate into a colder climate, they must become clothed with thicker fur, or have their constitutions altered. If they fail to be thus modified, they will cease to exist. The case, however, is widely different, as Mr. Wallace has with justice insisted, in relation to the intellectual and moral faculties of man. These faculties are variable ; and we have every reason to believe that the variations tend to be inherited. Therefore, if they were formerly of high importance to prime- val man and to his ape-like progenitors, they would have been perfected or advanced through natural selection. Of the high importance of the intellectual faculties there can be no doubt, for man mainly owes to them his predominant position in the world. We can see that, in the rudest state of society, the individuals who were the most sagacious, who invented and used the best weapons or traps, and who were best able to de: fend themselves, would rear the greatest number of offspring. The tribes which included the largest number of men thus en- dowed would increase in number and supplant other tribes. Numbers depend primarily on the means of subsistence, and this depends partly on the physical nature of the country, but in a much higher degree on the arts which are there practised. As a tribe increases and is victorious, it is often still further increased by the absorption of other tribes. The stature and 2 After a time the members or tribes which 1861, p. 131), thatthey are the co-descende are absorbed into another tribe assume, as ants ‘of the same ancestors, Sir Henry Maine remarks (‘‘ Ancient Law,” 144 THE DESCENT OF MAN. [PART ¥, strength of the men of a tribe are likewise of some importance for its success, and these depend in part on the nature and amount of the food which can be obtained. In Europe the men of the Bronze period were supplanted by a race more _ powerful, and, judging from their sword-handles, with larger hands ;° but their success was probably still more due to their superiority in the arts. All fhat we know about savages, or may infer from their traditions and from old monuments, the history of which is _ quite forgotten by the present inhabitants, show that from the : remotest times successful tribes have supplanted other tribes. Relics of extinct or forgotten tribes have been discovered throughout the civilized regions of the earth, on the wild — plains of America, and on the isolated islands in the Pacific — Ocean. At the present day civilized nations are everywhere supplanting barbarous nations, excepting where the climate opposes a deadly barrier ; and they succeed mainly, though not exclusively, through their arts, which are the products of the intellect. It is, therefore, highly probable that with man- kind the intellectual faculties have been mainly and gradually perfected through natural selection; and this conclusion is sufficient for our purpose. Undoubtedly it would be interest- ing to trace the development of each separate faculty from the state in which it exists in the lower animals to that in which it exists in man; but neither my ability nor knowledge permits the attempt. It deserves notice that, as soon as the progenitors of man be- came social (and this probably occurred at a very early period), the principle of imitation, and reason, and experience would have increased, and much modified the intellectual powers in a way of which we see only traces in the lower animals. Apes are much given to imitation, as are the lowest savages ; and the simple fact previously referred to, that after a time no ani- mal can be caught in the same place by the same sort of trap, shows that animals learn by experience, and imitate the cau- tion of others. Now, if some one man in a tribe, more saga- cious than the others, invented a new snare or weapon, or other means of attack or defence, the plainest self-interest, without the assistance of much reasoning power, would prompt the other members to imitate him ; and all would thus profit. The habitual practice of each new art must likewise in some sight degree strengthen the intellect. If the new invention # Morlot, “ Soc, Vaud. Sc Nats,” 1860, Ds 3946 CHAP. v.] MORAL FACULTIES. 145 were an important one, the tribe would increase in number, spread, and supplant other tribes. In a tribe thus rendered more numerous there would always be a rather greater chance of the birth of other superior and inventive members. If such men left children to inherit their mental superiority, the chance of the birth of still more ingenious members would be some- what better, and in a very small tribe decidedly better. Even if they left no children, the tribe would still include their blood-relations ; and it has been ascertained by agriculturists 4 that by preserving and breeding from the family of an animal which, when slaughtered, was found to be valuable, the desired character has been obtained. Turning now to the social and moral faculties. In order that primeval men, or the ape-like progenitors of man, should become social, they must have acquired the same instinctive feelings which impel other animals to live in a body; and they no doubt exhibited the same general disposition. They would have felt uneasy when separated from their comrades, for whom they would have felt some degree of love; they would have warned each other of danger, and have given mutual aid in attack or defence. All this implies some degree of sympathy, fidelity, and courage. Such social qualities, the paramount importance of which to the lower animals is. dis- puted by no one, were no doubt acquired by the progenitors of man in a similar manner, namely, through natural selection, aided by inherited habit. When two tribes of primeval man, living in the same country, came into competition, if (other circumstances being equal) the one tribe included a great num- ber of courageous, sympathetic, and faithful members, who were always ready to warn each other of danger, to aid and defend each other, this tribe would succeed better and conquer the other. Let it be borne in mind how all-important, in the never-ceasing wars of savages, fidelity and courage must be. The advantage which disciplined soldiers have over undis- ciplined hordes follows chiefly from the confidence which each man feels in his comrades. Obedience, as Mr. Bagehot has well shown,° is of the highest value, for any form of govern- ment is better than none. Selfish and contentious people will not cohere, and without coherence nothing can be effected. A * T have given instances in my “ Variation ‘‘ Physics and Politics,’’ in the “‘ Fortnightly of Animals under Domestication,” vol. ii, p. Review,’’ Nov., 1867; April 1, 1868; July t% 1869, since separately published. iG)—~Voal, 8 196. ® See a remarkable series of articles on 146 THE DESCENT OF MAN, {PART 2.' tribe rich in the above qualities would spread and be victorious _ over other tribes ; but in the course of time it would, judging from all past history, be in its turn overcome by some other tribe still more highly endowed. ‘Thus the social and moral qualities would tend slowly to advance and be diffused through- out the world. But it may be asked, how within the limits of the same tribe did a large number of members first become endowed with these social and moral qualities, and how was the standard of excellence raised ? It is extremely doubtful whether the off- spring of the more sympathetic and benevolent parents, or of those who were the most faithful to their comrades, would be reared in greater numbers than the children of selfish and treacherous parents belonging to the same tribe. He who was ready to sacrifice his life, as many a savage has been, rather than betray his comrades, would often leave no offspring to in- herit his noble nature. The bravest men, who were always willing to come to the front in war, and who freely risked their lives for others, would on an average perish in- larger numbers than other men. ‘Therefore it hardly seems probable that the number of men gifted with such virtues, or that the standard of their excellence, could be increased through nat- ural selection, that is, by the survival of the fittest; for we are not here speaking of one tribe being victorious over an- other. | Although the circumstances leading to an increase in the number of those thus endowed within the same tribe are too complex to be clearly followed out, we can trace some of the probable steps. In the first place, as the reasoning powers and foresight of the members became improved, each man would soon learn that if he aided his fellow-men, he would commonly receive aid in return. From this low motive he might acquire the habit of aiding his fellows; and the habit of performing benevolent actions certainly strengthens the feeling of sympathy which gives the first impulse to benevolent actions. Habits, moreover, followed during many generations, probably tend to be inherited. But another and much more powerful stimulus to the devel- opment of the social virtues is afforded by the praise and the blame of our fellow-men. To the instinct of sympathy, as we have already seen, it is primarily due that we habitually be- stow both praise and blame on others, while we love the for- mer and dread the latter when applied to eurselves ; and this = =? CHAP. V.] MORAL FACULTIES, 147 instinct no doubt was originally acquired, like aii the other social instincts, through natural selection. At how early a period the progenitors of man, in the course of their develop- ment, became capable of feeling and being impelled by the praise or blame of their fellow-creatures, we cannot, of course, say. But it appears that even dogs appreciate encouragement, praise, and blame. ‘The rudest savages feel the sentiment of glory, as they clearly show by preserving the trophies of their prowess, by their habit of excessive boasting, and even by the extreme care which they take of their personal appearance and decora- tions ; for unless they regarded the opinion of their (COA aEy such habits would be senseless. They certainly feel shame at the breach of some of their lesser rules, and apparently remorse, as shown by the case of the Australian who grew thin and could not rest from having de- layed to murder some other woman, so as to propitiate his dead wiie’s spirit. ‘Though I have not met with any other recorded case, it is scarcely credible that a savage who will sacrifice his life rather than betray his tribe, or one who will deliver him- self up as a prisoner rather than break his parole,® would not feel remorse in his inmost soul if he had failed in a duty which he held sacred. We may therefore conclude that primeval man, at a very remote period, was influenced by the praise and blame of his fellows. It is obvious that the members of the same tribe would approve of conduct which appeared to them to be for the general good, and would reprobate that which appeared evil. To do good unto others—to do unto others as ye would they should do unto you—is the foundation-stone of morality. It is, therefore, hardly possible to exaggerate the importance, during rude times, of the love of praise and the dread of blame. A man who was not impelled by any deep, instinctive feeling to sacrifice his life for the good of others, yet was roused to such actions by a sense of glory, would by his example excite the same wish for glory in other men, and would strengthen by exercise the noble feeling of admiration. He might thus do far more good to his tribe than by begetting offspring with a tendency to inherit his own high character. With increased experience and reason, man perceives the more remote consequences of his actions, and the self-regarding virtues, such as temperance, chastity, etc., which during early 6 Mr. Wallace gives cases in his “Contributions to the Theory of Natural Selection,” 1870, P» 354s 148 THE DESCENT OF MAN. (PART i times are, as we have before seen, utterly disregarded, come ta be highly esteemed or even held sacred. I need not, however, repeat what I have said on this head in the fourth chapter. Ultimately our moral sense or conscience becomes a highly complex sentiment—originating in the social instincts, largely guided by the approbation of our fellow-men, ruled by reason, self-interest, and in later times by deep religious feelings, and confirmed by instruction and habit. . It must not be forgotten that although a high standard of morality gives but a slight or no advantage to each individual man and his children over the other men of the same tribe, yet that an increase in the number of well-endowed men and an advancement in the standard of morality will certainly give an immense advantage to one tribe over another. A tribe includ- ing many members who, from possessing in a high degree the spirit of patriotism, fidelity, obedience, courage, and sympathy, were always ready to aid one another, and to sacrifice them- selves for the common good, would be victorious over most other tribes; and this would be natural selection. At all times throughout the world tribes have supplanted other tribes ; and as morality is one important element in their success, the standard of morality and the number of well-endowed men will thus everywhere tend to rise and increase. It is, however, very difficult to form any judgment why one particular tribe and not another has been successful and has risen in the scale of civilization. Many savages are in thesame condition as when first discovered several centuries ago. As Mr. Bagehot has remarked, we are apt to look at progress as normal in human society ; but history refutes this. The an- cients did not even entertain the idea, nor do the Oriental nations at the present day. According to another high author- ity, Sir Henry Maine,’ ‘‘the greatest part of mankind has never shown a particle of desire that its civil institutions should be improved.’’ Progress seems to depend on many concurrent favorable conditions, far too complex to be followed out. But it has often been remarked that a cool climate, from leading to industry and to the various arts, has been highly favorable thereto. The Esquimaux, pressed by hard necessity, have succeeded in many ingenious inventions, but their climate has been too severe for continued progress. Nomadic habits, whether over wide plains or through the 7“ Ancient Law,’ 1861, p. 22. For Mr. Bagehot’s remarks, “‘ Fortnightly Review,” April 1, 1868, p. 452. ™“ CIVILIZED NATIONS. 149 CHAP. V.} dense forests of the tropics, or along the shores of the sea, have in every case been highly detrimental. While observing the barbarous inhabitants of Tierra del Fuego, it struck me that the possession of some property, a fixed abode, and the union of many families under a chief, were the indispensable requi- sites for civilization. Such habits almost necessitate the culti- vation of the ground ; and the first steps in cultivation would probably result, as I have elsewhere shown,’ from some such accident as the seeds of a fruit-tree falling on a heap of refuse, and producing an unusually fine variety. The problem, how- ever, of the first advance of savages toward civilization is at present much too difficult to be solved. Natural Selection as Affecting Civilized Nations.—\ have hitherto only considered the advancement of man from a semi- human condition to that of the modern savage. But some remarks on the action of natural selection on civilized nations may be worth adding. ‘This subject has been ably discussed by Mr. W. R. Greg,® and previously by Mr. Wallace and Mr. Galton.” Most of my remarks are taken from these three authors. With savages, the weak in body or mind are soon eliminated ; and those that survive commonly exhibit a vigor- ous state of health. We civilized men, on the other hand, do our utmost to check the process of elimination; we build asylums for the imbecile, the maimed, and the sick; we ‘insti- tute poor-laws ; and our medical men exert their utmost skill to save the life of everyone to the last moment. There is reason to believe that vaccination has preserved thousands who from a weak constitution would formerly have succumbed to small-pox. - Thus the weak members of civilized societies propagate their kind. No one who has attended to the breed- ing of domestic animals will doubt that this must be highly injurious to the race of man. It is surprising how soon a want of care, or care wrongly directed, leads to the degeneration of a domestic race; but, excepting in the case of man himself, hardly any one is so ignorant as to allow his worst animals to breed. ® “The Variation of Animals and Plants under Domestication,’ vol. i. p. 309. ® “Fraser’s Magazine,’ Sept., 1868, p. 353. ‘This article seems to have struck many persons, and has given rise to two remarkable essays and a rejoinder in the “Spectator,” Oct. 3d and 17th, 1868. It has also been discussed in the ‘*Q. Journal of Science,” 1860, p. 152, and by Mr. Law- son Tait in the ‘‘ Dublin Q. Journal of Medi- cal Science,” Feb., 1869, and by Mr. E. Ray Lankester in his ‘Comparative Longevity,” 1870, p. 128. Similar views appeared pre. viously in the ‘* Australasian,” July 13, 1867, I have borrowed ideas from several of these writers. 10 Kor Mr. Wallace, see ‘‘ Anthropolog. Review,” as before cited. Mr. Galton in **Macmillan’s Magazine,” Aug., 1865, p. 318; also his great work, ‘Hereditary Genius,” 1890. O52 THE DESCENT OF MAN. [PART 4 The ad which we feel impelled to give to the helpless is wiainly an incidental result of the instinct of sympathy, which was originally acquired as part of the social instincts, but sub- sequently rendered, in the manner previously indicated, more tender and more widely diffused. Nor could we check our sympathy, even at the urging of hard reason, without deterio- ration in the noblest part of our nature. ‘The surgeon may harden himself while performing an operation, for he knows that he is acting for the good of his patient; but if we were inten- tionally to neglect the weak and helpless, it could only be for a. contingent benefit, with an overwhelming present evil. We must therefore bear the undoubtedly bad effects of the weak surviving and propagating their kind; but there appears to be at least one check in steady action, namely, that the weaker and inferior members of society do not marry so freely as the sound ; and this check might be indefinitely increased by the weak in body or mind refraining from marriage, though this is more to be hoped for than expected. In every country in which a large standing army is kept up, the finest young men are taken by the conscription or are enlisted. They are thus exposed to early death during war, are often tempted into vice, and are prevented from marrying dur- ing the prime of life. On the other hand, the shorter and feebler men, with poor constitutions, are left at home, and consequently have a much better chance of marrying and propagating their kind." Man accumulates property and bequeaths it to his children, so that the children of the rich have an advantage over the poor in the race for success, independently of bodily or mental su- periority. On the other hand, the children of parents who are short-lived, and are therefore on an average deficient in health and vigor, come into their property sooner than other children, and will be likely to marry earlier, and leave a larger number of offspring to inherit their inferior constitutions. But the inheri- tance of property by itself is very far from an evil; for without the accumulation of capital the arts could not progress ; and it is chiefly through their power that the civilized races have extended, and are now everywhere extending their range, so as to take the place of the lower races. Nor does the moderate accumulation of wealth interfere with the process of selection. When a poor man becomes moderately rich, his children entcr 11 Prof, H. Fick (‘‘ Einfluss der Natur- has some good remarks on this head, and om wissenschaft auf das Recht,” June, 1872) other such points. | { : : Pees ee CHAP. V.§ CIVILIZED NATIONS. 153 trades or professions in which there is struggle enough, so that the able in body and mind succeed best. The presence of a body of well-instructed men, who have not to labor for their daily bread, is important to a degree which cannot be over- estimated ; as all high intellectual work is carried on by them, and on such work material progress of all kinds mainly de- pends, not to mention other and higher advantages. No doubt wealth when very great tends to convert men into useless drones, but their number is never large; and some degree of elimination here occurs, for we daily see rich men, who hap- pen to be fools or profligate, squandering away their wealth. Primogeniture with entailed estates is a more direct evil, though it may formerly have been a great advantage by the creation of a dominant class, and any government is better than none. Most eldest sons, though they may be weak in body or mind, marry, while the younger sons, however superior in these respects, do not so generally marry. Nor can worthless eldest sons with entailed estates squander their wealth. But here, as elsewhere, the relations of civilized life areso complex that some compensatory checks intervene. The men who are rich through primogeniture are able to select generation after generation the more beautiful and charming women ; and these must generally be healthy in body and active in mind. The evil consequences, such as they may be, of the continued preservation of the same line of descent, without any selection, are checked by men of rank always wishing to increase their wealth and power ; and this they effect by marrying heiresses. But the daughters of parents who have produced single children are themselves, as Mr. Galton * has shown, apt to be sterile ; and thus noble families are continually cut off in the direct line, and their wealth flows into some side channel ; but, unfortunately, this channel is not determined by superiority of any kind. Although civilization thus checks in many ways the action of natural selection, it apparently favors the better development of the body, by means of good food and the freedom from occasional hardships. This may be inferred from civilized men having been found, wherever compared, to be physically stronger than savages.'® They appear also to have equal powers of endurance, as has been proved in many adventurous expedi- tions. Even the great luxury of the rich can be but little det- 18 “Hereditary Genius,” 1870, pp. 132- __ 1° Quatrefages, ‘‘ Revue des Cours Sciex: 140 ~ tifiques,” 1867-68, p. 659, eer 152 THE DESCENT OF MAN. (PART L rimental, for the expectation of life of our aristocracy, at all ages and of both sexes, is very little inferior to that of healthy English lives in the lower classes." We will now look to the intellectual faculties. Ifin each grade of society them embers were divided into two equal bod- ies, the one including the intellectually superior and the other the inferior, there can be little doubt that the former would succeed best in all occupations, and rear a greater number of children. Even in the lowest walks of life, skill and ability must be of some advantage; though in many occupations, owing to the great division of labor, a very smallone. Hence in civilized nations there will be some tendency to an increase both in the number and in the standard of the intellectually able. But I do not wish to assert that this tendency may not be more than counterbalanced in other ways, as by the multi- plication of the reckless and improvident ; but even to such as these, ability must be some advantage. It has often been objected to views like the foregoing, that the most eminent men who have ever lived have left no offspring to inherit their great intellect. Mr. Galton says,” ‘refully written. are extracted from the same striking paper. 156 THE DESCENT OF MAN. [PART & that widows and widowers in France suffer in comparison with the married avery heavy rate of mortality; but Dr. Farr attributes this to the poverty and evil habits consequent on the disruption of the family, and to grief. On the whole, we may conclude with Dr. Farr that the lesser. mortality of married than of unmarried men, which seems to be a general law, ‘‘ is mainly due to the constant elimination of imperfect types, and to the skilful selection of the finest individuals out of each suc- cessive generation ;’’ the selection relating only to the mar- riage state, and acting on all corporeal, intellectual, and moral qualities.» We may, therefore, infer that sound and good men who, out of prudence, remain for a time unmarried, do not suf- fer a high rate of mortality. If the various checks specified in the two last paragraphs, and perhaps others as yet unknown, do not prevent the reckless, the vicious, and otherwise inferior members of society from increasing at a quicker rate than the better class of men, the nation will retrograde, as has too often occurred in the history of the world. We must remember that progress is no invariable tule. It is very difficult to say why one civilized nation rises, becomes more powerful, and spreads more widely, than another ; or why the same nation progresses more quickly at one time than at another. We can only say that it depends on, an in- crease in the actual number of the population, on the number of the men endowed with high intellectual and moral faculties, as well as on their standard of excellence. Corporealstructure appears to have little influence, except so far as vigor of body leads to vigor of mind. It has been urged by several writers that as high intellectual powers are advantageous to a nation, the old Greeks, who stood some grades higher in intellect than any race that has ever existed,* ought, if the power of natural selection were real, to have risen still higher in the scale, increased in number, and stocked the whole of Europe. Here we have the tacit assump- tion, so often made with respect to corporeal structures, that there is some innate tendency toward continued development in | mind and body. But development of all kinds depends on many concurrent favorable circumstances. Natural selection acts only tentatively. Individuals and races may have acquired 25 Dr. Duncan remarks (‘ tiene leaving the unmarried columns crowded with Fertility,” etc., 1871, page 334) on this sub- the sickly and unfortunate.” ject : 26 See the ingenious and original argu- ** At every age the healthy and beautiful go ment on this subject by Mr. anes “Hes ever from the unmarried side to the married, reditary Genius,” pp. 340-34@ CHAP. v.] CIVILIZED NATIONS, 157 certain indisputable advantages, and yet have perished from failing in other characters. ‘The Greeks may have retrograded from a want of coherence between the many small states, from the small size of their whole country, from the practice of slavery, or from extreme sensuality ; for they did not succumb until **they were enervated and corrupt to the very core.’’* The western nations of Europe, who now so immeasurably surpass their former savage progenitors, and stand at the sum- mit of civilization, owe little or none of their superiority to direct inheritance from the old Greeks, though they owe much to the written works of that wonderful people. Who can positively say why the Spanish nation, so dominant at one time, has been distanced in the race? ‘The awakening of the nations of Europe from the dark ages is astill more perplex- ing problem. At that early period, as Mr. Galton has remarked, almost all the men of a gentle nature, those given to meditation or culture of the mind, had no refuge except in the bosom of a Church which demanded celibacy ;*° and this could hardly fail to have had a deteriorating influence on each successive generation. During this same period the Holy Inquisition se- lected with extreme care the freest and boldest men in order to burn or imprison them. In Spain alone some of the best men—those who doubted and questioned, and without doubting there can be no progress—were eliminated during three cen- turies at the rate of a thousand a year. The evil which the Catholic Church has thus effected is incalculable, though no doubt counterbalanced to a certain, perhaps to a large, extent in other ways ; nevertheless, Europe has progressed at an un- paralleled rate. The remarkable success of the English as colonists, compared to other European nations, has been ascribed to their ‘‘ daring and persistent energy ;’’ a result which is well illustrated by comparing the progress of the Canadians of English and French extraction ; but who can say how the English gained their en- ergy? There is apparently much truth in the belief that the wonderful progress of the United States, as well as the character of the peopie, are the results of natural selection ; for the more energetic, restless, and courageous men from all parts of Europe have emigrated during the last ten or twelve generations to that 37 Mr. Greg, “‘ Fraser’s Magazine,” Sep- already (‘ Principles of Geology,” vol. ii., tember, 1868, p. 357. 1868, p. 489) in a striking passage called 28 ‘* Hereditary Genius,’’ 1870, pp. 357— attention to the evil influence of the Holy 59. The Rev. F. W. Farrar, (‘‘Fraser’s Inquisition in having, through selection, Maz.” Aug., 1870, p. 257) advances argu- lowered the general standard of intelligence ments on the other side. Sir C. Lyell had in Europe, 158 THE DESCENT OF MAN. {PART 1 great country, and have there succeeded best.” Looking to the distant future, I do not think that the Rev. Mr. Zincke takes an exaggerated view when he says: ® «‘ All other series of events—as that which resulted in the culture of mind in Greece, and that which resulted in the empire of Rome—only appear to have purpose and value when viewed in connection with, or rather assubsidiary to . . .. the great stream of Anglo- Saxon emigration to the west.’’. Obscure as is the problem of the advance of civilization, we can at least see that a nation which produced during a lengthened period the greatest num- ber of highly intellectual, energetic, brave, patriotic, and benev- olent men, would generally prevail over less favored nations. Natural selection follows from the struggle for existence ; and this from a rapid rate of increase. It is impossible not to regret bitterly, but whether wisely is another question, the rate at which man tends to increase; for this leads in barbarous tribes to infanticide and many other evils, and in civilized nations to ubject poverty, celibacy, and to the late marriages of the prudent. But as man suffers from the same physical evils as the lower animals, he has no right to expect an immunity from the evils consequent on the struggle forexistence. Had he not been sub- jected during primeval times to natural selection, assuredly he would never have attained to his present rank. Since we seein many parts of the world enormous areas of the most fertile land capable of supporting numerous happy homes, but peopled only by a few wandering savages, it might be argued that the struggle for existence had not been sufficiently severe to force man up- ward to his highest standard. Judging from all that we know of man and the lower animals, there has always been sufficient variability in their intellectual and moral faculties for a steady advance through natural selection. No doubt such advance demands many favorable concurrent circumstances ; but it may well be doubted whether the most favorable would have sufficed, had not the rate of increase been rapid, and the consequent struggle for existence extremely severe. It even appears from what we see, for instance, in parts of South America, that a people which may be called civilized, such as the Spanish set- tlers, is liable to become indolent and to retrograde, when the conditions of life are very easy. With highly civilized nations continued progress depends in a subordinate degree on natural 29 Mr. Galton,‘* Macmillan’s Mag.,”Aug., 2° ‘‘ Last Winter in the United States,” 1865, p. 325. See, also, * Nature,” “On Dar- 1268, P. 29- winism and National Life,” Dec. 1869,p. 184 CHAP. Vv.) CIVILIZED NATIONS. 150 selection ; for such nations do not supplant and exterminate one another as do savage tribes. Nevertheless, the more intelligent members within the same community will succeed better in the long run than the inferior, and leave a more numerous progeny, and this is a form of natural selection. ‘The more efficient causes of progress seem to consist of a good education during youth while the brain is impressible, and of a high standard of excellence, inculcated by the ablest and best men, embodied in the laws, customs, and traditions of the nation, and enforced by public opinion. It should, however, be borne in mind that the enforcement of public opinion depends on our appreciation of the approbation and disapprobation of others; and this appreciation is founded on our sympathy, which it can hardly be doubted was originally developed through natural selection as one of the most important elements of the social instincts.*! On the Evidence that all Civilized Nations were once Bar- barous.—The present subject has been treated in so full and admirable a manner by Sir J. Lubbock,® Mr. Tylor, Mr. M‘Lennan, and others that I need here give only the briefest summary of their results. ‘The arguments recently advanced by the Duke of Argyll,® and formerly by Archbishop Whately, in favor of the belief that man came into the world as a civil- ized being, and that all savages have since undergone degra- dation, seein to me weak in comparison with those advanced on the other side. Many nations, no doubt, have fallen away in civilization, and some may have lapsed into utter bar- barism, though on this latter head I have met with no evidence. The Fuegians were probably compelled by other conquering hordes to settle in their inhospitable country, and they may have become in consequence somewhat more degraded ; but it would be difficult to prove that they have fallen much below the Botocudos, who inhabit the finest parts of Brazil. The evidence that all civilized nations are the descendants of barbarians, consists, on the one side, of clear traces of their former low condition in still-existing customs, beliefs, lan- guage, etc.; and on the other side, of proofs that savages are independently able to raise themselves a few steps in the scale of civilization, and have actually thus risen. The evidence on the first head is extremely curious, but cannot be here given ; I refer to such cases as that of the art of enumeration, which, 31 Tam much indebted to Mr. John Mor- 32 “* On the Origin of Civilization,” ‘* Proc, ley for some good criticisms on this subject: of the Ethnological Society,” November 26, see, also, Broca, ‘‘ Les Sélections,” “ Revue 1867. : d’Anthropologie,” 1872, *“* « Primeval Man,” 1869, 160 THE DESCENT OF MAN. [PART 1. as Mr. Tylor clearly shows by reference to the words still used in some places, originated in counting the fingers, first of one hand and then of the other, and lastly of the toes. We have traces of this in our own decimal system, and in the Roman numerals, where, after the V., which is supposed to be an ab- breviated picture of a human hand, we pass on to VI., etc., when the other hand no doubt was used. So again, ‘‘ when we speak of threescore and ten, we are counting by the vigesi- mal system, each score thus ideally made standing for 20—for ‘one man’ as a Mexican or Carib would put it.’’ #4 According to a large and increasing school of philologists, every language bears the marks of its slow and gradual evolu- tion. So it is with the art of writing, for letters are rudiments of pictorial representations. It is hardly possible to read Mr. M‘Lennan’s work® and not admit that almost all civilized nations still retain traces of such rude habits as the forcible capture of wives. What ancient nation, as the same author asks, can be named that was originally monogamous? The primitive idea of justice, as shown by the law of battle and other customs of which vestiges still remain, was likewise most rude. Many existing superstitions are the remnants of former false religious beliefs. ‘The highest form of religion—-the grand zdea of God hating sin and loving righteousness—wes unknown during primeval times. | Turning to the other kind of evidence: Sir J. Lubbock has shown that some savages have recently improved a little in some of their simpler arts. From the extremely curious ac- count which he gives of the weapons, tools, and arts in use among savages in various parts of the world, it cannot be doubted that these have nearly all been independent discover- ies, excepting perhaps the art of making fire. The Australian boomerang is a good instance of one such independent discov- ery. The Tahitians when first visited had advanced in many respects beyond the inhabitants of most of the other Polyne- sian islands. There are no iust grounds for the belief that the high culture of the native Peruvians and Mexicans was de- 34 “Royal Institution of Great Britain,” March 15, 1867. Also, ‘‘ Researches into the Early History of Mankind,” 186s. 35 * Primitive Marriage,’ 1865. See, likewise, an excellent article, evidently by the same author, in the ‘‘ North British Re- view,”’ July; 1869. Also, Mr. L. H. Morgan, “ A Conjectural Solution of the Origin of the Class System of Relationship,” in ** Proc. American Acaa. of Sciences,”’ vol. vii., February, 1868. Prof. Schaaffhausen (** Anthropolog. Review,” October, 1869, p. 373) remarks on *‘ the vestiges of human sacrifices found both in Homer and the Old Testament.” 36 Sir J. Lubbock, “‘ Prehistoric Times,” 2d edit. 1869, chap. xv. and xvi. et assim. See, also, the excellent ninth chapter in Ty- lor’s *“* Early History of Mankind,” 2d edit, 1870. : ; _ CHAP. VI.) AFFINITIES AND GENEALOGY. 165 rived from abroad ; * many native plants were there cultivated, and a few native animals domesticated. We should bear in mind that, judging from the small influence of most mission- aries, a wandering crew from some semi-civilized land, if washed to the shores of America, would not have produced any marked effect on the natives, unless they had already be- come somewhat advanced. Looking to a very remote period in the history of the world, we find, to use Sir J. Lubbock’s well-known terms, a paleolithic and neolithic period; and no one will pretend that the art of grinding rough flint tools was a borrowed one. In all parts of Europe, as far east as Greece, in Palestine, India, Japan, New Zealand, and Africa, including Egypt, flint tools have been discovered in abundance; and of their use the existing inhabitants retain no tradition. There is also indirect evidence of their former use by the Chinese and ancient Jews. Hence there can hardly be a doubt that the inhabitants of these countries, which include nearly the whole civilized world, were once in a barbarous condition. To believe that man was aboriginally civilized and then suf- fered utter degradation in so many regions, is to. take a pitia- bly low view of human nature. It is apparently a truer and more cheerful view that progress has been much more general than retrogression ; that man has risen, though by slow and interrupted steps, from a lowly condition to the highest stand- ard as yet attained by him in knowledge, morals, and religion. CHAPTER VI. ON THE AFFINITIES AND GENEALOGY OF MAN. | Position of man in the animal series—The natural system genealogical- Adaptive characters of slight value—Various small points of resem- blance between man and the Quadrumana—Rank of man in the natu- ral system—Birthplace and antiquity of man—Absence of fossil con- necting-links—Lower stages in the genealogy of man, as inferred, firstly from his affinities, and secondly from his structure—Early an- drogynous condition of the Vertebrata—Conclusion. Even if it be granted that the difference between man and his nearest allies is as great in corporeal structure as some natural- ists maintain, and although we must grant that the difference 87 Dr. F. Miiller has made some good Novara: Anthropolog. Theii,” Abtheil, iid, remarks to this effect in the ‘Reise der 1868, s. 127. 162 THE DESCENT OF MAN. {PART & between them 1s immense in mental power, yet the facts given in the earlier chapters appear to declare, in the plainest man- ner, that man is descended from some lower form, notwith- standing that connecting-links have not hitherto been discov- ered. Man is liable to numerous slight and diversified variations, which are induced by the same general causes, are governed and transmitted in accordance with the same general laws, as in the lower animals. Man has multiplied so rapidly that he has necessarily been exposed to struggle for existence, and con- sequently to natura] selection. He has given rise to many races, some of which differ so much from each other that they have often been ranked by naturalists as distinct species. His body is constructed on the same homological plan as that of other mammals. He passes through the same phases of embry- ological development. He retains many rudimentary and use- less structures, which no doubt were once serviceable. Char- acters occasionally make their re-appearance in him, which we have reason to believe were possessed by his early progenitors. If the origin of man had been wholly different from that of all other animals, these various appearances would be mere empty deceptions ; but such an admission is incredible. These ap- pearances, on the other hand, are intelligible, at least to a large extent, if man is the co-descendant with other mampals of some unknown and lower form. Some naturalists, from being deeply impressed with the men- tal and spiritual powers of man, have divided the whole organic world into three kingdoms—the Human, the Animal, and the Vegetable—thus giving to man a separate kingdom.’ Spiritual powers cannot be compared or classed by the naturalist ; but he may endeavor to show, as I have done, that the mental fac- ulties of man and the lower animals do not differ in kind, although immensely in degree. A difference in degree, how- ever great, does not justify us in placing man in a distinct kingdom, as will perhaps be best illustrated by comparing the mental powers of two insects, namely, a coccus or scale-insect and an ant, which undoubtedly belong to the same class. The difference is here greater than, though of a somewhat different kind from, that between man and the highest mammal. The female coccus, while young, attaches itself by its proboscis to 1 Isidore Geoffroy St.-Hilaire gives a de- cations: ‘‘ Hist. Nat. Gén.,” tam. ii, 1859, tailed account of the position assigned to pp. 170-189. man by various naturalists in their classifi- wmar.vij AFFINITIES AND GENEALOGY. 103 a plant; sucks the sap, but never moves again; is fertilized and lays eggs ; and this is its whole history. On the other hand, to describe the habits and mental powers of worker- ants, would require, as Pierre Huber has shown, a large vol- ume; I may, however, briefly specify a few points. Ants certainly communicate information to each other, and several unite for the same work, or for games of play. They recog- nize their fellow - ants after months of absence, and feel sym- pathy for each other. ‘They build great edifices, keep them clean, close the doors in the evening, and post sentries.. They make roads as well as tunnels under rivers, and temporary bridges over them, by clinging together. ‘They collect food for the community, and when an object too large for entrance is brought to the nest, they enlarge the door, and afterward build it up again. ‘They store up seeds, of which they pre- vent the germination, and which, if damp, are brought up to the surface to dry. They keep aphides and other insects as milch-cows. They go out to battle in regular bands, and freely sacrifice their lives for the common weal. They emi- grate according to a preconcerted plan. ‘They capture slaves. They move the eggs of their aphides, as well as their own eggs and cocoons, into warm parts of the nest, in order that they may be quickly hatched ; and endless similar facts could be given.” On the whole, the difference in mental power between an ant and a coccus is immense ; yet no one has ever dreamed of placing these insects in distinct classes, much less in distinct kingdoms. No doubt the difference is bridged over by other insects ; and this is not the case with man and the higher apes. But we have every reason to believe that the breaks in the series are simply the results of many forms having become ex- ‘tinct. Prof. Owen, relying chiefly on the structure of the brain, has divided the mammalian series into four sub-classes. One of these he devotes to man; in another he’places both the Marsupials and the Monotremata; so that he makes man as distinct from all other mammals as are these two latter groups conjoined. This view has not been accepted, as far as I am aware, by any naturalist capable of forming an independent judgment, and therefore need not here be further considered. We can understand why a classification founded on any single 2 Some of the most interesting facts ever mirable work, ‘‘ Harvesting Ants,” etc.,1873, ee on the habits of ants are given also, ‘‘L’Instinct chez les Insectes,” by Ir. Belt, in his ‘* Naturalist in Nicara- M. George Pouchet, ‘‘Revue des Deux qua,” 1874. See, also, Mr, Moggridge’s ad- Mondes,” February, 1870, p. 682, 164. THE DESCENT OF MAN, [PART 1, character or organ—even an organ so wonderfully complex and important as the brain—or on the high development of the mental faculties, is almost sure to prove unsatisfactory. This principle has indeed been tried with hymenopterous insects ; but when thus classed by their habits or instincts, the arrange- ment proved thoroughly artificial.* Classifications may, of course, be based on any character whatever, as on size, color, or the element inhabited ; but naturalists have long felt a pro- found conviction that there is a natural system. This system, it is now generally admitted, must be, as far as possible, genea- logical in arrangement—that is the co-descendants of the same form must be kept together in one group, apart from the co- descendants of any other form ; but if the parent-forms are re- lated, so will be their descendants, and the two groups together will form a larger group. The amount of difference between the several groups-—that is the amount of modification which each has undergone—is expressed by such terms as genera, families, orders, and classes. As we have no record of the lines of descent, the pedigree can be discovered only by ob- serving the degrees of resemblance between the beings which are to be classed. For this object numerous points of resem- blance are of much more importance than the amount of simi- larity or dissimilarity in a few points. If two languages were found to resemble each other in a multitude of words and points of construction, they would be universally recognized as having sprung from a common source, notwithstanding that they differed greatly in some few words or points of construc- tion. But with organic beings the points of resemblance must not consist of adaptations to similar habits of life: two animais may, for instance, have had their whole frames modified for living in the water, and yet they will not be brought any nearer to each «ther in the natural system. Hence we can see how it is thac resemblances in several unimportant structures, in useless and rudimentary organs, or not now functionally active, or in an embryological condition, are by far the most serviceable for classification ; for they can hardly be due to adaptations within a late period ; and thus they reveal the old lines of descent or of true affinity. We can further see why a great amount of modification in some one character ought not to lead us to separate widely any two organisms. A part which already. differs much from the same part in other allied forms has already, according to the 8 Westwood, ‘* Modern Class of Insects,” vol. ii., 1840, p. 87. cuar.vi.) | AFFINITIES AND GENEALOGY, 165 theory of evolution, varied much; consequently it would (as long a@ the organism remained exposed to the same exciting conditions) be liable to further variations of the same kind ; and these, if beneficial, would be preserved, and thus be con- tinually augmented. In many cases the continued develop- ment of a part, for instance, of the beak of a bird, or of the teeth of a mammal, would not aid the species in gaining its food, or for any other object; but with man we can see no definite limit to the continued development of the brain and mental faculties, as far as advantage is concerned. ‘lherefore in determining the position of man in the natural or genealogi- eal system, the extreme development of his brain ought not to outweigh a multitude of resemblances in other less important or quite unimportant points... The greater number of naturalists who have taken into con- sideration the whole structure of man, including his mental faculties, have followed Blumenbach and Cuvier, and have placed man in a separate Order, under the title of the Bimana, and therefore on an equality with the orders of the Quad- rumana, Carnivora, etc. Recently many of our best natural- ists have recurred to the view first propounded by Linnzeus, so remarkable for his sagacity, and have placed man in the same Order with the Quadrumana, under the title of the Primates. The justice of this conclusion will be admitted ; for, in the first place, we must bear in mind the comparative insignificance for classification of the great development of the brain in man, and that the strongly marked differences between the skulls of man and the Quadrumana (lately insisted upon by Bischoff, Aeby, and others) apparently follow from their differently de- veloped brains. In the second place, we must remember that nearly all the other and more important differences between man and the Quadrumana are manifestly adaptive in their nature, and relate chiefly to the erect position of man; such as the structure of his hand, foot, and pelvis, the curvature of his spine, and the position of his head. The family of Scals offers a good illustration of the small importance of adaptive char- acters for classification. ‘These animals differ from all other Carnivora, in the form of their bodies and in the structure of their limbs, far more than does man from the higher apes; yet in most systems, from that of Cuvier to the most recent one by Mr. Flower,‘ seals are ranked as a mere family in the Order of the Carnivora. If man had not been his own classifier, he 4 “ Proc. Zoolog. Soc.,” 1863, Pr q . 166 THE DESCENT OF MAN. [PART L would never have thought of founding a separate order for his own reception. It would be beyond my limits, and quite beyond my knowl- edge, even to name the innumerable points of structure in which man agrees with the other Primates. Our great anat- omist and philosopher, Prof. Huxley, has fully discussed this subject,® and concludes that man in all parts of his organization differs less from the higher apes than these do from the lower members of the same group. Consequently there ‘‘ is no justi- fication for placing man in a distinct order.”’ In an early part of this work I brought forward various facts, showing how closely man agrees in constitution with the higher mammals; and this agreement must depend on our close simi- larity in minute structure and chemical composition. I gave, as instances, our lability to the same diseases, and to the attacks of allied parasites; our tastes in common for the same stimulants, and the similar effects produced by them, as well as by various drugs, and other such facts. As small unimportant points of resemblance between man and the Quadrumana are not commonly noticed in systematic works, and as, when numerous, they clearly reveal our relation- ship, I will specify a few such points. The relative position of our features is manifestly the same ; and the various emotions are displayed by nearly similar movements of the muscles and skin, chiefly above the eyebrows and round the mouth. Some few expressions are, indeed, almost the same, as in the weep- ing of certain kinds of monkeys and in the laughing noise made by others, during which the corners of the mouth are drawn backward, and the lower eyelids wrinkled. The external ears are curiously alike. In man the nose is much more prominent than in most monkeys; but we may trace the commencement of an aquiline curvature in the nose of the Hoolock Gibbon ; and this in the Semnopithecus nasica is carried to a ridiculous extreme. The faces of many monkeys are ornamented with beards, whiskers, or mustaches. The hair on the head grows to a great length in some species of Semnopithecus ; ® and in the Bonnet monkey (Macacus radiatus) it radiates from a point on the crown, with a parting down the middle. It is com- monly said that the forehead gives to man his noble and intel- lectual appearance ;. but the thick hair on the head of the Bon- 5 “Evidence as to Man’s Placein Nature,” | © Isid. Geoffroy, “ Hist. Nat. Gén., "tom. 1863, PD. 70 €¢ Passtme Un 1859, D. 217+ . : : uz. CHAP. vi) AFFINITIES AND GENEALOGY. 157 net monkey terminates downward abruptly, and is succeeded — by hair so short and fine that at a little distance the forehead, with the exception of the eyebrows, appears quite naked. It has been erroneously asserted that eyebrows are not present in any monkey. In the species just named the degree of naked- ness of the forzhead differs in different individuals; and Esch- richt states‘ that in our children the limit between the hairy scalp and the naked forehead is sometimes not well defined ; so that here we seem to have a trifling case of reversion to a pro- genitor in whom the forehead had not as yet become quite naked. It is well known that the hair on our arms tends to converge from above and below to a point at the elbow. ‘This curious arrangement, so unlike that in most of the lower mammals, is common to the gorilla, chimpanzee, orang, some species of Hylobates, and even to some few American monkeys. But in Hylobates agtlis the hair on the forearm is directly downward or toward the wrist in the ordinary manner ; andin 4. /ar itis nearly erect, with only a very slight forward inclination ; so that in this latter species it is in a transitional state. It can hardly be doubted that with most mammals the thickness of the hair on the back and its direction is adapted to throw off the rain ; even the transverse hairs on the fore-legs of a dog may serve for this end when he is coiled up asleep. Mr. Wallace, who has carefully studied the habits of the orang, remarks that the convergence of the hair toward the elbow on the arms of the orang may be explained as serving to throw off the rain, for this animal during rainy weather sits with its arms bent, and with the hands clasped round a branch or over its head. Ac- cording to Livingstone, the gorilla also ‘‘ sits in pelting raia with his hands over his head.’’® If the above explanation is correct, as seems probable, the direction of the hair on our own arms offers a curious record of our former state ; for no one supposes that it is now of any use in throwing off the rain; nor, in our present erect condition, is it properly directed for this purpose. It would, however, be rash to trust too much to the principle of adaptation in regard to the direction of the hair in man or his early progenitors ; for it is impossible to study the figures given by Eschricht of the arrangement of the hair on the hu- 7 “Ueber die Richtung der Haare,” etc. 8 Quoted by Reade, ‘‘ The African Sketch Miiller’s “Archiv fiir Anat. und Phys.,” 1837, Book,” vol. i., 1873, p. 152. & 63. 168 THE DESCENT OF MAN, (PART & man foetus (this being the same as in the adult) and not agree with this excellent observer that other and more complex causes have intervened. ‘lhe points of convergence seem to stand in some relation to those points in the embryo which are last closed in during development. ‘There appears also to exist some relation between the arrangement of the hair on the limbs and the course of the medullary arteries.? It must not be supposed that the resemblances between man and certain apes in the above and many other points—such as in having a naked forehead, long tresses on the head, etc.—are all necessarily the result of unbroken inheritance from a com- mon progenitor, or of subsequent reversion. Many of these resemblances are more probably due to analogous variation, which follows, as I have elsewhere attempted to show,! from co-descended organisms having a similar constitution, and hav- ing been acted on by like causes.inducing similar modifications. With respect to thesimilar direction of the hairon the forearms of man and certain monkeys, as this character is common to almost all the anthropomorphous apes, it may probably be attributed to inheritance ; but this is not certain, as some very distinct American monkeys are thus characterized. Although, as we have now seen, man has no just right to form a separate Order for his own reception, he may perhaps claim a distinct Sub-order or Family. Prof. Huxley, in his last work," divides the Primates into three Sub-orders ; namely, the Anthropidz with man alone, the Simiadz. including monkeys of all kinds, and the Lemuridz with the diversified genera of lemurs. As far as differences in certain important points of structure are concerned, man may no doubt rightly claim the rank of a Sub-order ; and this rank is too low, if we look chiefly to his mental faculties. Nevertheless, from a genealogical point of view, it appears that this rank is too high, and that man ought to form merely a Family, or possibly even only a Sub-family. If we imagine three lines of descent pro- ceeding from a common stock, it is quite conceivable that two of them might after the lapse of ages be so slightly changed as still to remain as species of the same genus, while the third line might become so greatly modified as to deserve to rank as 9 On the hair in Hylobates, see ‘‘Nat. ‘Contributions to the Theory of Natural History of Mammals,” by C. L. Martin, Selection,” 1870, p. 344. : 1841, p. 415. Also, Isid. Geoffroy on the 10 ** Origin of Species,’’ 5th edit., 1869, p. American monkeys and other kinds, ‘‘Hist. 194. ‘‘The Variation of Animals and Plants Nat. Gén.,” vol. ii, 1859, pp. 216, 243. Esch- under Domestication,” vol. i.. 1868, p. 348. ticht, ibid.’ s. 46, 55, 61. Owen, ‘‘Anat. of _*! “ An Introduction to the Classification Vertebrates,” vol. ili. p. 619. Wallace, of Animals,” 1869, p. og- ; : { CHAP. VI.) AFFINITIES AND GENEALOGY, 16 a distinct Sub-family, Family, or even Order. But in this case it is almost certain that the third line would still xecain 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 differences in some few points —that is, to the amount of modification undergone ; and how much to close resemblance in numerous unimportant points, as indicating the lines of descent or genealogy. To attach much weight to the few but strong differences is the most. obvious and perhaps the safest course, though it appears more correct to pay great attention to the many small 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 Simiade.. This family is divided by almost all naturalists into the Catarrhine group, or Old World monkeys, all of which are characterized (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 characterized 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 Catar- rhine or Old World division ; nor does he resemble the Platy- rhines more closely than the Catarrhines in any characters, ex- cepting 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 pro- duced a man-like 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 Catarrhine division.” The anthropomorphous apes, namely, the gorilla, chimpanzee, orang, and hylobates, are by most naturalists separated from the other Old World monkeys, as a distinct sub-group. I am 43 This is nearly the same classification whichanswer to the Catarrhines, the Cebide, as that provisionally adopted by Mr. St. and the Hapalida—these two latter groups George Mivart (‘‘Transact. Philosoph. answering to the Platyrhines. Mr. Mivart Soc.,” 1867, p. 300), who, after separating still abides by the same view; see ‘ Nat- the Lemuridz, divides the remainder of the ure,” 1871, p. 481. tes into the Hominida, the Simiadze te (H)—Vol. 3 170 THE DESCENT OF MAN. {Part rf. 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 Mr. 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. Gaudry’s wonderful discover- ies 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 groups 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 Cat- arrhine group, but in other peculiar characters, such as the ab- sence of a tail and of callosities, and in general appearance, we may infer that some ancient member of the anthropomorphous sub-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-like creature, resembling the higher anthropomorphous apes in so many re- spects. 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 Simiadz, namely, the Catarrhine 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 di- verged to any considerable extent from each other, would still have formed a single natural group; but some of the species or incipient genera would have already begun to indicate by their diverging characters the future distinctive marks of the Cat- arrhine and Platyrhine divisions. Hence the members of this supposed ancient group would not have been so uniform in their dentition, or in the structure of their nostrils, as are the existing Catarrhine monkeys in one way and the Platyrhines in 13 “Transact. Zoolog. Soc.,” vol. vi, | 4 Mr. St.G. Mivart, “Transact. Phil, 1867, p. 214. Soc.” 1867, p. 410 ? CHAP. VI., AFFINITIES AND GENEALOGY, 171 another way, but would have resembled in this respect the allied Lemuride, which differ greatly from each other in the form of their muzzles,® and to an extraordinary degree in their dentition. The Catarrhine and Platyrhine monkeys agree in a multitude of characters, as is shown by their unquestionably belonging to one and the same Order. ‘The many characters which they possess in common can hardly have been independently ac- quired by so many distinct species; so that these characters must have been inherited. But a naturalist would undoubt- edly have ranked as an ape or a monkey, an ancient form which possessed many characters common to the Catarrhine and Platy- rhine monkeys, other characters in an intermediate condition, and some few, perhaps, distinct from those now found in either group. And as man from a genealogical point of view belongs to the Catarrhine or Old World stock, we must conclude, how- ever much the conclusion may revolt our pride, that our early progenitors would have been properly thus designated.* But we must not fall into the error of supposing that the early pro- genitor of the whole Simian stock, including man, was identi- cal with, or even closely resembled, any existing ape or mon- key. On the Birthplace and Antiquity of Man.—We are naturally led to inquire, where was the birthplace of man at that stage of descent when our progenitors diverged from the Catarrhine stock ?. The fact that they belonged to this stock clearly shows 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 speculate on this subject ; for two or three anthropomorphous apes, one the Dryopithecus ™ of Lartet, nearly as large as a man, and closely allied to Hylobates, existed in Europe during 15 Messrs. Murie and Mivart on the Lem- uroidea, ** Transact. Zoolog. Soc.,”’ vol. vii., 1869, Dp, 4 16 Hickel has come to this same con- clusion. See ‘“ Ueber die Entstehung des Menschengeschlechts,” in Virchow’s $ ung. gemein, wissen. Vortrage,” 1868, s. 61. Also his ‘‘ Natiirliche Schép- fungsgeschichte,” 1868, in which he gives in detail his views on the genealogy of man. 17 Dr. C. Forsyth Major, ‘* Sur les Sin- ges Fossiles trouvés en Italie ;” ** Soc, Ital. des Sc. Nat.,” tom. xv., 1872. 172 THE DESCENT OF MAN, (PART L 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 hairy covering, he probably inhabited a hot country—a circumstance favorable for the frugiferous diet on which, judging from analogy, he subsisted. We are far from knowing how long ago it was when man first diverged from the Catarrhine stock ; but it may have occurred at an epoch as remote as the Eocene period ; for that the higher apes had diverged from the lower apes as early as the Upper Mio- cene period is shown 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 favor- able circumstances ; we know, however, that some have’ re- tained 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 amount of modification in certain characters in com- parison 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 evolu- tion. 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 Lemuridze—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 centuries, the civilized races of man will almost certainly exterminate, and replace, the savage races throughout the world. At the same time the anthropamorphous apes, as Prof. Schaaffhausen has remarked, will no doubt be exterminated. The break between man and his nearest allies will then be wider, for it will inter- vene between man in a more civilized state, as we may hope, 48 “Anthropological Review,” April, 1867, p. 236 . cnap.vi] AFFINITIES AND GENEALOGY. 173 even than the Caucasian, and some ape as low as a baboon, instead of, as now, between the negro or Australian and the gorilla. With respect to the absence of fossil remains, serving to connect man with his ape-like progenitors, no one will lay much stress on this fact who reads Sir C. Lyell’s discussion,’ where he shows 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 ex- tinct ape-like creature have not as yet been searched by geol- ogists. Lower Stages in the Genealogy of Man.—We have seen that man appears to have diverged from the Catarrhine or Old World division of the Simiade, after these had diverged from the New World division. We will now endeavor to follow the remote traces of his genealogy, trusting principally to the mutual affin- ities between the various classes and orders, with some slight reference to the periods, as far as ascertained, of their succes- sive appearance on theearth. The Lemuridz stand below and near to the Simiadz, and constitute a very distinct. family of the Primates, or, according to Hiackel and others, a distinct Order. ‘This group is diversified and broken to an extraor- dinary 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 Ma- layan archipelago, where they have not been exposed to so seyere 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 vari- ous considerations it is probable that the Simiadz were origi- nally developed from the progenitors of the existing Lemuridee ; 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 geologi- cal period, and their range was formerly much more extensive than at present. Hence the Placentata are generally supposed 28 “ Elements of Geology,’’ 1865, pp. 58 30 ‘* Man’s Place in Nature,” p. 10 g8s. “ Antiquity of Man,’ 1863, P+ 145+ - . wathccee 174 THE DESCENT OF MAN. {PART & to have been derived from the Implacentata or Marsupials ; not, however, from forms closely resembling the existing Mar- supials, but from their early progenitors. ‘The Monotremata are plainly allied to the Marsupials, forming a third and still lower division in the great mammalian series. ‘They are repre- sented 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 favorable concur- rence of circumstances. ‘The Monotremata are eminently in- teresting, as leading in several important points of structure toward the class of reptiles. | In attempting to trace the genealogy of the Mammalia, and therefore of man, lower down in the series, we become involved in greater and greater obscurity ; but, as a most capable judge, Mr. Parker, has remarked, we have good reason to believe that no true bird or reptile intervenes in the direct line of de- scent. He who wishes to see what ingenuity and knowledge can effect, may consult Prof. Hackel’s works.*4 J 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, espe- cially during their embryonic state. As the class of fishes is the most lowly organized, 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 an- imals so distinct as a monkey, an elephant, a humming-bird, asnake, a frog, and a fish, etc., could all have sprung from the same parents, will appear monstrous to those who have not attended to the recent progress of natural history. For this belief implies the former existence of links binding closely to- cether all these forms, now so utterly unlike. Nevertheless, it is certain that groups of animals have ex- isted, 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 toward reptiles ; and Prof. Huxley has discovered, and is confirmed by Mr. Cope and 21 Elaborate tables are gilen in his 42), says, that he considers the phylum or ** Generelle Morphologie” (B. ii s. cliii. and lines of descent of the Vertebrata to be ad- s. 425) ; and with more especial reference to mirably discussed by Hackel, although he man in his ‘‘Natiirliche Schéd,fungsge- differs on some points. He expresses, also, schichte,” 1868. Prof. Huxley, inreviewing his high estimate of the general tenor and this latter work (‘‘The Academy,” 1869, p. spirit of the whole work. AFFINITIES AND GENEALOGY, 175 others, that the Dinosaurians are in many important characters intermediate between certain reptiles and certain birds—the birds referred to being the ostrich-tribe (itself evidently a widely diffused remnant of a lasger group) and the Archeop- teryx, that strange Secondary bird, with a long lizard-like tail. Again, according to Prof. Owen,” the Ichthyosaurians—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 con- structed on what is called a generalized 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 alsosome few Ganoid fishes, have been preserved from utter extinction by inhabiting rivers, which are harbors 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, etc. ; so that it was classed by the older naturalists among 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 Mollusca; but they have recently been placed by some naturalists among the Vermes or worms. Their larvze somewhat resemble tadpoles in shape,* and have the power of swimming freely about. M. Kovalevsky* has lately observed that the larve of Ascidians are related to the CHAP, VI.J filament. It was, as sketched by me, under 22 ‘* Palzontology,” 1860, p. 1 a simple microscope, plainly divided by 99- 33 At the Falkland Islands [I had the satisfaction of seeing, in April, 1833, and therefore some years before any other nat- uralist, the locomotive larvz of a compound Ascidian, closely allied to Synoicum, but apparently generically distinct from it. The tail was heat five times as long as the ob- long head, and terminated in a very fine transverse opaque partitions, which I pre- sume represent the great cells figured by Kovalevsky. Atan early stage of develop. ment the tail was closely coiled round the head of the larva. 24 ‘*Mémoires de l’Acad. des Sciences de St. Pétersbourg,” tom. x No. 15, 1866, 176 THE DESCENT OF MAN. [PART L Vertebrata in their manner of development, in the relative position of the nervous system, and in possessing a structure closely like the chorda dorsalis of vertebrate animals ; and in this he has been since confirmed by Prof. Kupffer. M. Kovalevsky writes to me from Naples, that he has now carried these observations yet further; and, should his results be well established, the whole will form a discovery of the very great- est value. ‘Thus, if we may rely on embryology, ever the safest guide in classification, it seems that we have at last gained a clew to the source whence the Vertebrata were derived.” We should then be justified in believing that at an extremely re- mote period a group of animals existed, resembling in many respects the larvz 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 kingdom by giving birth to the Vertebrata. We have thus far endeavored rudely to trace the genealogy of the Vertebrata by the aid of their mutual affinities. We will now look to man as he exists; and we shall, J think, be able partially to restore the structure of our early progenitors, during successive, periods, but not in due order of time. This can be effected by means of the rudiments which man still retains, by the characters which occasionally make their appearance in him through reversion, and by the aid of the principles of morphology and embryology. ‘The various facts 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 provided with a tail, having the proper muscles. Their limbs and bodies were also acted on by many muscles which now only occasionally reappear, but are normally present in the Quadrumana. At this or some.earlier period, the great artery and nerve of the humerus ran through a supra-condyloid fora- men. ~The intestine gave forth a much larger diverticulum or cecum than that now existing. The foot was then prehensile, 26 But I am bound to add that some com- petent judges dispute this conclusion ; for instance, M. Giard, in a series of papers in the ‘‘ Archives de Zoologie Expérimentale,” for 1872. Nevertheless, this naturalist re- marks, p. 281, ‘‘ L’organisation de la larve ascidienne en dehors de toute hypothése et de toute théorie, nous montre comment la nature peut produire la disposition fonda- mentale du type vertebré (l’existence d’une corde dorsale) chez un invertébré par la seule condition vitale de l’adaptation, et cette simple possibilité du passage supprime Vabime entre les deux sous-régnes, encore bien qu’on ignore par ou le passage s'est fait en réalité,”* AFFINITIES AND GENEALOGY. 177 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 great canine teeth, which served them as formidable weapons. At a much earlier period the uterus was double; the excreta were voided through a cloaca; and the eye was protected by a third eyelid or nictitating membrane. At a still earlier period the progenitors of man must have been aquatic in their habits ; for morphology plainly tells us that our lungs consist of a modified swim-bladder, which once served as a float. The clefts on the neck in the embryo of man show where the branchize once existed. In the lunar or weekly recurrent periods of some of our functions we apparently still retain traces of our primordial birthplace, a shore washed by the tides. At about this same early period the true kidneys were replaced by the corpora wolffiana, The heart existed asa simple pulsating vessel ; and the chorda dorsalis took the place ef 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 organized 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 ap- pears to have been hermaphrodite or androgynous. But here we encounter a singular difficulty. In the mammalian class the males possess rudiments of a uterus with the adjacent pas- sage, in their vesiculze prostaticee ; they bear also rudiments of Mammz, and some male Marsupials have traces of a marsupial sac.** Other analogous facts could be added. Are we, then, to suppose that some extremely ancient mammal continued androgynous, after it had acquired the chief distinctions of its class, and therefore after it had diverged from the lower classes of the vertebrate kingdom? This seems very improbable, for CHAP, V1.) 46 This is the conclusion of Prof. Gegen- baur, one of the highest authorities in com- parative anatomy; see ‘f Grundziige der vergleich. Anat.,’’ 1870, s.876 The result has been arrived at chiefly from the study of the Amphibia ; but it appears from the re- searches of Waldeyer (as quoted in “ Jour- gal of Anat. and Phys.,” 1869, p. 161), that the sexual organs of even ‘‘the higher verte- brata are, in their early condition, hermaph- rodite.’”? Similar views have long been held by some authors, though until recently without a firm basis. 27 ‘The male ‘Thylacinus offers the best instance. Owen, ‘‘ Anatomy of Verte- brates,” vol uli. p. 77% 178 THE DESCENT OF MAN. [PART L we have to look to fishes, the lowest of all the classes, to find any still existent androgynous forms.** ‘That various accessory parts, proper to each sex, are found in a rudimentary con- dition in the opposite sex, may be explained by such organs having been gradually acquired by the one sex, and then trans- mitted 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 colors, acquired for battle or orna- ment by male birds, and inherited by the females in an imper- fect 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 ori- fices, but no nipples ; and as these animals stand at the very base of the mammalian series, it is probable that the progeni- tors 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 Prof. Turner informs me, on the author- ity of Kélliker and Langer, that in the embryo the mam- mary glands can be distinctly traced before the nipples are in the least visible ; and the development of successive parts in the individual generally represents and accords with the devel- opment of successive beings in the same line of descent. The Marsupials differ from the Monotremata by possessing nipples ; so that probably these organs were first acquired by the Mar- supials, 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 stil! re- mained androgynous after they had approximately acquired their present structure. . How then are we to account for male mammals possessing mammz? 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. 28 Hermaphroditism has been observed in ranus. Prof. Ercolani has recently shown several species of Serranus, as well as in some other fishes, where it is either normal and symmetrical or abnormal and uni- lateral. Dr. Zouteveen has given me refer- ences on this subject, more especially to a paper by Prof. Halbertsma, in the ‘‘ Trans- act. of the Dutch Acad. of Sciences,” vol. xvi. Dr. Giinther doubts the fact, but it has now been recorded by too many good observers to be any longer disputed. Dr. M. Lessona writes to me that he has verified the observations made by Cavolini on Ser- (‘* Accad. delle Scienze,” Bologna, Dec. 28, 1871) that eels are androgynous. 29 Prof. Gegenhbaur has shown (“ Jena- ische Zeitschrift,” d. vii. p. 212) that two distinct types of nipples prevail throughout the several mammahan orders, but that it is quite intelligible hew both could have Lecn derived from the nipples of the Marsupials,, and the latter from tose of the Mon«ire- mata. See, also, a wemoir by Tir Max Huss, on the mammary glands, thid.; 4. vias Ds 176, PL —- ———_—-—————_ CHAP. VI.J AFFINITIES AND GENEALOGY, 179 It may be suggested, as another view, that long after the progenitors of the whole mammalian class had ceased to be androgynous, both sexes yielded milk, and thus nourished their young ; and in the case of the Marsupials, that both sexes car- ried their young in marsupial sacs. ‘This will not appear altogether improbable, if we reflect that the males of existing syngnathous fishes receive the eggs of the females in their ab- dominal pouches, hatch them, and afterward, 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 own thighs, keeping them there until the tadpoles are born; that certain male birds undertake the whole duty of incubation, and that male pigeons, as well as the females, feed their nestlings with a secretion from their crops. But the above suggestion first occurred to me from the mammary glands of male mammals being so much more per- fectly developed than the rudiments of the other accessory re- productive parts, which are found in the one sex though proper to the other. The mammary glands and nipples, as they exist in male mammals, can indeed hardly be called rudimen- tary ; they are merely not fully developed, and not function- ally active. They are sympathetically affected under the in- fluence of certain diseases, like the same organs in the female. They often secrete afew 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 mammez. In man and some other male mammals these organs have been known occasionally to become so well developed during maturity as to yield a fair supply of milk. Now if we suppose that dur- ing a former prolonged period male mammals aided the females in nursing their offspring,*! and that afterward from some cau=e (as from the production of a smaller number of young) tne 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 3° Mr. Lockwood believes (as quoted in “ Quart. Journal of Science,’? April, 1868, p- 269), from what he has observed of the Boston Soc. of Nat. Hist.,” Sept. 15, 1857; also Prof, Turner, in “* Journal of Anat. and Phys.,’? Nov. 1, 1866, p. 78. Dr. Giinther development of Hippocampus, that the walls 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, has likewise described similar cases, 31 Mdlle, C. Royer has suggested a sim- ilar view in her “ Origine oe Homme,” etc., 1870, 180 THE DESCENT OF MAN. corresponding age of maturity. But at an earlier age these organs would be left unaffected, so that they would be almost equally well developed in 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 specialization of the several parts of a being—when arrived at maturity, as I should be in- clined to add. Now as organisms have become slowly adapted to diversified lines of life by means of natural selection, their parts will have become more and more differentiated and specialized for various functions, from the advantage gained by the division of physiological labor. The same part appears often to have been modified first for one purpose, and then long afterward for some other and quite distinct purpose; and thus all the parts are rendered more and more complex. But each organisrn still retains the general type of structure of the pro- genitor from which it was aboriginally derived. In accord- ance with this view it seems, if we turn to geological evidence, that organization 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, how- ever, be supposed that groups of organic beings are always supplanted, and disappear as soon as they have given birth te other and more perfect groups. ‘The latter, though victorious over their predecessors, may not have become better adapted for ali places in the economy of nature. Some old forms ap- pear 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 organized group as perfect representatives of their an- cient predecessors. The most ancient progenitors in the kingdom of the Verte- brata, at which we are able to obtain an obscure glance, ap- parently consisted of a group of marine animals,” resembling (rar 1, 82 The inhabitants of the seashore must be greatly affected by the tides; animals living either about the mcaxz high-water mark, or about the 2zea7 low-water mark, pass through a complete cycle of tidal changes in a fortnight. Consequently, their food supply will undergo marked changes week by week. The vital functions of such, animals, living under these condi- tions for many generations, can hardly fail to run their course in regular weekly periods. New it is a mysterious fact that in the higher and now terrestrial Vertebrata, as well as in other classes, many normal and abnormal processes have one or more whole weeks as their periods ; this would be ren- dered intelligible if the Vertebrata are de- scended from an animal allied to the exist- ing tidal Ascidians. Many instances of such periodic processes might be given, as -emar.vi.j} AFFINITIES AND GENEALOGY, 181 the larvee of existing Ascidians. ‘These animals probably gave rise to a group of fishes, as lowly organized as the lancelet ; and from these the Ganoids, and other fishes like the Lepidosiren, must have been developed. From such fish a very small advance would carry us on to the Amphibians. We have seen that birds and reptiles were once intimately connected together ; and the Monotremata now connect mammals with reptiles in a slight degree. But no one can at present say by what line of descent the three higher and related classes, namely, mammals, birds, and reptiles, were derived from the two lower vertebrate classes, namely, amphibians and fishes. In the class of mam- mals 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 Lemuridz ; and the interval is not very wide from these to the Simiadz. The Simiadz then branched off into two great stems, the New World and Old World mon- keys; and from the latter, at a remote period, Man, the won- der and glory of the Universe, proceeded. Thus we have given to man a pedigree of prodigious length, but not, it may be said, of noble quality. The world, it has often been remarked, appears as if it had long been preparing for the advent of man ; and this, in one sense, is strictly true, for he owes his birth to a long line of progenitors. If any sin- gle 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 rec- Ognize our parentage ; nor need we feel ashamed of it. The most humble organism is something much higher than the in- organic 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 gestation of mammals, the duration of fevers. etc. The hatching of eggs affords also a good example, for, according to Mr. Bartlett (“Land and Water,” Jan. 7, 1871), the eggs of the pigeon are hatched in two weeks; those of the fowl in three; those of the duck in four ; those of the goose in five ; and those of the ostrich in seven weeks. As far as we can judge, a recurrent period, if approximately of the right duration for any Process or function, would not, when once gained, be liable to change; consequently it might be thus transmitted through aimost 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 peri- od of gestation in each mammal, and the hatching of each bird’s eggs, and many other vital processes, thus betray to us the primordial birthplace of these animals. 182 THE DESCENT OF MAN. {PART &, CHAPTER VIL. ON THE RACES OF MAN. The nature and value of specific characters—Application to the races of man—Arguments in favor 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 cf races—The formation of races —The effects of crossing—Slight influence of the direct action of the conditions of life—Slight or no influence of naturai selection—Sexual selection. It is not my intention here to describe the several so-called races of men; but I am about to inquire what is the value of the differences between them under a classificatory point of view, and how they have originated. In determining whether two or more allied forms ought to be ranked as species or va- rieties, naturalists are practically guided by the following con- siderations, namely: the amount of difference between them, and whether such differences relate to few or many points of structure, and whether they are of physiological importance ; but more especially whether they are constant. Constancy of character is what is chiefly valued and sought for by naturalists. Whenever it can be shown, or rendered probable, that the forms in question have remained distinct for a long period, this becomes an argument of much weight in favor of treating them as species. Even a slight degree of sterility between any two forms when first crossed, or in their offspring, is generally considered as a decisive test of their specific distinctness; and their continued persistence without blending within the same area is usually accepted as sufficient evidence, either of some degree of mutual 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 to- gether any two closely allied forms, is probably the most im- portant of all the criterions of their specific distinctness; and this is a somewhat different consideration from mere constancy of character, for two forms may be highly variable and yet not yield intermediate varieties. Geographical distribution is often —— — a 183 4 ‘CHAP. VII] THE RACES OF MAN. brought into play unconsciously and sometimes consciously ; so that forms living in two widely separated areas, in which most of the other inhabitants are specifically distinct, are them- selves usually looked at as distinct ; but in truth this affords no aid in distinguishing geographical 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 differ- ence between the races, we must make some allowance for our nice powers of discrimination gained by the long habit of ob- serving 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 supposed ; certain negro tribes must be excepted, while others, as Dr. Rohlfs writes to me, and as I have myself seen, have Caucasian features. ‘This general similarity is well shown by the French photographs in the Collection Anthropologique du Muséum 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 shown them have remarked. Never- theless, these men, if seen alive, would undoubtedly appear very distinct, so that we are clearly much influenced in our judgment by the mere color of the skin and hair, by slight dif- ferences in the features, and by expression. There is, however, no doubt that the various races, when carefully compared and measured, differ much from each other —as in the texture of the hair, the relative proportions of all parts of the body,” the capacity of the lungs, the form and capacity of the skull, and even in the convolutions of the brain.? But it would be an endless task to specify the numer- ous points of difference. The races differ also in constitution, in acclimatization, and in liability to certain diseases. Their mental characteristics are likewise very distinct; chiefly as it ? “ History of India,” 1841, vol. i. p. 323. the capacity of the lungs,” p. 4712. See also Father Ripa makes exactly the same remark with respect to the Chinese. A vast number of measurements of Whites, Blacks, and Indians are given in the “ Investigations in the Military and An- ire Statistics of American Soldiers,” by B. A. Gould, 1869, pp. 298-358; ‘On the numerous and valuable tables, by Dr. Weisbach, from the observations of Dr. Scherzer and Dr. Schwarz in the ‘* Reise der Novara: Anthropolog. Theil,” 1867. 3 See, for instance, Mz. Marshall’s ac count of the brain of a Bushwoman, i@ *‘ Phil. Transact,,” 1864, P. 519. ad 134 THE DESCENT OF MAN. would appear in their emotional, but partly in their intellectual faculties. Everyone who has had the opportunity of compari- son must have been struck with the contrast between the taci- turn, even morose, aborigines of South America and the light- hearted, talkative negroes. ‘There is a nearly similar contrast between the Malays and the Papuans,‘ who live under the same physical conditions, and are separated from each other only by a narrow space of sea. We will first consider the arguments which may be advanced in favor of classing the races of man as distinct species, and then the arguments on the other side. If a naturalist, who had never before seen a Negro, Hottentot, Australian, or Mon- golian, were to compare them, he would at once perceive that they differed in a multitude of characters, some of slight and some of considerable importance. On inquiry he would find that they were adapted to live under widely different climates, an] that they differed somewhat in bodily constitution and ruental disposition. If he were then told that hundreds of similar specimens could be brought from the same countries, he would assuredly declare that they were as good species as many to which he had been in the habit of affixing specific names. This conclusion would be greatly strengthened as soon as he had ascertained that these forms had all retained the same character for many centuries; and that negroes, appar ently identical with existing negroes, had lived at least 4,000 years ago.> He would also hear, on the authority of an excel- lent observer, Dr. Lund,® that the human skulls found in the caves of Brazil, entombed with many extinct mammals, be- longed to the same type as that now prevailing throughout the American Continent. Our naturalist would then perhaps turn to geographical dis- 4 Wallace, * The Malay Archipelago,” tan (‘‘ Races of Man,” 1850, p. 201), speak- (PART 1 ~ vol. ii., 1869, p. 178. 5 With respect to the figures in 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 recognizable representations of the dozen or more nations which some au- thors believe that they can recognize. Even some of the most sirongly marked races cannot be identified with that degree of unanimity which might have been expected from what has been written on the subject. Thus Messrs. Nott and Gliddon (‘‘ Types of Mankind,” p. 148) state that Rameses II., or the Great, has features superbly Euro- ean ; whereas Knox, another firm believer the specific distinctness of the races of ing of young Memnon (the same as Ra- meses IJ., as I am informed 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 sta- tue of Amunoph III., I agreed with two officers of the establishment, both competent judges, that he had a strongly marked ne- gro type of features; but Messrs. Nott and Gliddon (ibid., p. 146, fig. 53) describe him as a hybrid, but not of “ negro intermixt- ure.’ 6 As quoted by Nott and Glidden, ‘* Types of Mankind,” 1854, p. 439. They give also corroborative evidence ; but C. Vogt thinks that the subject requires further investige- tion, _ a. r CHAP, VII.] THE RACES OF MAN. ° 185 tribution, and he would probably declare that those forms must be distinct species which differ not only in appearance, but are fitted for hot as well as damp or dry countries, and for the Arctic regions. He might appeal to the fact that no species in the group next to man, namely, the Quadrumana, can resist a low temperature, or any considerable change of climate ; and that the species which come nearest to man have never been reared to maturity, even under the temperate climate of Europe. He would be deeply impressed with the fact, first noticed by Agassiz,’ that the different races of man are distributed over the world in the same zoclogical provinces as those inhabited by undoubtedly distinct species and genera of mammals. ‘This is manifestly the case with the Australian, Mongolian, and Negro races of man; in a less well-marked manner with the Hot- tentots; but plainly with the Papuans and Malays, who are separated, as Mr. Wallace has shown, by nearly the same line which divides the great Malayan and Australian zoological provinces. ‘The Aborigines of America range throughout the Continent ; and this at first appears opposed to the above rule, for most of the productions of the Southern and Northern halves differ widely : yet some few living forms, as the opossum, range from the one into the other, as did formerly some of the gigantic Edentata. The Esquimaux, like other Arctic animals, extend round the whole polar regions. It should be observed that the amount of difference between the mammals of the several zoo- logical provinces does not correspond with the degree of separa- tion 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 ot 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 naturalist would lay much stress on the fact of their external parasites being specifically distinct. All the more stress would be laid on this fact, as it would be an exceptional one ; for I am informed by Mr. Denny that the most different kinds of dogs, fowls, and pigeons, in England, are infested by the same species of Pediculi or lice. Now Mr. A. , 7 “ Diversity of Origin of the Human Races,” in the “ Christian Examiner Tuly, 1850 186 THE DESCENT OF MAN. (PART L Murray has carefully examined the Pediculi collected in differ- ent countries from the different races of man ; * and he finds that they differ not only in colur, but in the structure of their claws and iimbs. In every case in which many specimens were ob- tained the differences were constant. ‘The surgeon of a whaling ship in the Pacific assured me that when the Pediculi with which some Sandwich Islanders on board swarmed, strayed on to the bodies of the English sailors, they died in the course of three or four days. ‘These Pediculi were darker colored, and appeared different from those proper to the natives of Chiloe, in South America, of which he gave me specimens. ‘These, again, appeared larger and much softer than European lice. Mr. Murray procured four kinds from Africa, namely, from the Negroes. of the Eastern and Western coasts, from the Hottentots and Kaffirs; two kinds from the natives of Australia; two from North and two from South America. In these latter cases it may be presumed that the Pediculi came from natives inhab- iting different districts. With insects slight structural differ- ences, if constant, are generally esteemed of specific value: and the fact of the races of man being infested by parasites which appear to be specifically distinct might fairly be urged as an argument that the races themselves ought to be classed as dis- tinct species. Our supposed naturalist, having proceeded thus far in his in- vestigation, would next inquire whether the races of men, when crossed, were in any degree sterile. He might consult the work9 of Prof. Broca, a cautiovg 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 shown to be almost valueless. The half-castes are killed by the pure blacks: and an account has lately been published of eleven half- caste youtks murdered and burnt at the same time, whose re- mains were found by the police.” Again, it has often been said that when mulattoes intermarry they produce few children ; 8 «Transact. R. Soc. of Edinburgh,” vol. who have borne children to a white mam Xxii., 1861, p. 567. are afterward sterile with their own race, is 2*°On the Phenibaiees of Hybridity in disproved. M.A. de Quatrefages has also the Genus Homo,” Eng. translat., 1864. collected (‘*‘ Revue des Cours Scientifiques,” +9 See the interesting letter by Mr. T. A. March, 1869, p. 239) much evidence that Murray, in the “ Anthropoleg. Review,” Australians and Europeans are not sterile April, 1868; p. liu. In this letter Count when crossed, Strzelecki’s statement,that Australian women 4 5 vv 3 ; CHAP. VII. THE RACES OF MAN. 187 on the other hand, Dr. Bachman, of Charleston," positively as- serts that he has known mulatto families which have intermarried for several generations, and have continued on an average as fertile as either pure whites or pure blacks. Inquiries formerly made by Sir C. Lyell on this subject led him, as he informs 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 number, considering all the circumstances of the case, seems small ; but it may partly be accounted for by the degraded and anomalous position of the class, and by the profligacy of the women. A certain amount of absorption of wulattoes into negroes must always be in progress; and this would lead to’an apparent diminution of the former. The in- ferior vitality of mulattoes is spoken of in a trustworthy work ® as a well-known phenomenon; and this, alihough a different consideration from their lessened fertility, may perhaps be advanced as a proof of the specific distinctness of the parent races. No doubt both animal and vegetable hybrids, when produced from extremely distinct species, are liable to pre- mature death; but the parents of mulattoes cannot be put under the category of extremely distinct species. The com- mon Mule, so notorious for long life and vigor, and yet so ‘sterile, shows how little necessary connection there is in hy- _brids between lessened fertility and vitality; other analogous cases could be cited. Even if it should hereafter be proved that all the races of men were perfectly fertile together, he who was inclined from other reasons to rank them as distinct species might with justice argue that fertility and sterility are not safe criterions of specific dis- tinctness. We know that these qualities are easily affected by changed conditions of life, or by close interbreeding, and thar 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 11 “An Examination of Prof. Agassiz’s Sketch of the Nat. Provinces of the Animal World,” Charleston, 1855, p. 44. 12 Dr, Rohifs writes to me that he found the mixed races in the Great Sahara, de- rived from Arabs, Berbers, and Negroes of three tribes, extraordinarily fertile. On the other hand, Mr. Winwood Reade informs me that the negroes on the Gold Coast, though admiring white men and mulattoes, have a maxim that mulattoes should not intermarry, as the children are few and sickly. This be- lief, as Mr. Reade remarks, deserves atten- tion, 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. 13 “* Military and SoA pen Statistics of American Soldiers,” by B. A. Gould, 1869, P- 319 LOU THE DESCENT OF MAN. {PART I. fertile. The degrees of sterility do not coincide strictly with the degrees of difference between the parents in external struct- ure 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 favor of the Pal- lasian doctrine, that domestication tends to eliminate the sterility which is so general a result of the crossing of species in a state of nature. From these several considerations it may be justly urged that the perfect fertility of the intercrossed races of man, if established, would not absolutely preclude us from tanking them as distinct species. Independently of fertility, the characters presented by the offspring 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 concJusion that no general rules of this kind can be trusted. The ordinary result of a cross is the production of a blended or intermediate form; but in certain cases some of the offspring take closely after one 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. Rohlfs in- forms 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 14 “The Variation of Animals and Plants under Domestication,” vol. ii. p. 109. may here remind the reader that the sterility of species when crossed is not a specially acquired quality, but, like the incapacity of certain trees to be grafted together, is inci- dental on other acquired differoages. ‘The nature of these differences is unknown, but they relate more especially to the reproduc- tive system, and much less so to external structure or to ordinary differences in consta- tution. One important element in the ste- rility of crossed species apparently lies in one or both having been long habituated to fixed conditions ; for we know that changed conditions have a special influence on the reproductive system, and we have good rea- son to believe (as before remarked) that the fluctuating conditions of domestication tend to eliminate that sterility which is so general with species, in a natural state,when crossed. It has elsewhere been shown by me (ibid., vol. ii. p. 185, and ‘‘Origin of Species,” 5th edit., p. 317), that the sterility of crossed spe- cies has not been acquired through natural selection : we can see that when two forms have already been rendered very sterile, it as scarcely possible that their sterility should rarely piebald. On the other be augmented by the preservation or sur- vival of the more and more sterile individe uals; for as the sterility increases, fewer and fewer offspring will be produced from which to breed, and at last only single individuals will be produced, at the rarest intervals. But there is even a higher grade of sterility than this. Both Gartner and KOlreuter have proved that in genera of plants includ- img 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 shown by. the swelling of the germen. It is here mani- festly impossible to select the more sterile individuals, which have already ceased to yield seeds; so that the acme of sterility, when the germen alone is affected, cannot have been gained through selection. This acme, and no doubt the other grades of sterility, are the incidental results of certain unknown differences in the constitution of the reproductive system of the species which are crossed. __ 75 “The Variation of Animals,” etc., vel li. P. 92. EEE el oe CHAP. vil.” THE RACES OF MAN, 189 hand, it is notorious that in America mulattoes commonly present an intermediate appearance. We have now seen that a naturalist might feel himself fully justified in ranking the races of man as distinct species ; for he has found that they are distinguished by many differences in structure and constitution, some being of importance. These differences have also remained nearly constant for very long periods of time. Our naturalist will have been in some degree influenced by the enormous range of man, which is a great anomaly in the class of mammals, if mankind be viewed as a single species. He will have been struck with the distribution of the several 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 their specific identity. On the other side of the question, if our supposed naturalist were to inquire whether the forms of man keep distinct like ordinary species, when mingled together in large numbers in the same country, he would immediately discover that this was by no means the case. In Brazil he would behold an immense mongrel population of Negroes and Portuguese ; in Chiloe and other parts of South America he would behold the whole population consisting of Indians and Spaniards blended in various degrees. In many parts of the same continent he would meet with the most complex crosses between Negroes, Indians, and Europeans ; and, judging from the vegetable king- dom, 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 Eng- lish blood ; and in the Fiji Archipelago a population of Poly- nesian and Negritos crossed in all degrees. Many analogous cases could be added; for instance, in Africa. Hence the races of man are not sufficiently distinct to inhabit the same country without fusion; and the absence of fusion affords the usual and best test of specific distinctness. Our naturalist would likewise be much disturbed as soon as he perceived that the distinctive characters of all the races were highly variable. This fact strikes everyone cn first be- 16M. de Quatrefages has given (‘‘ Anthro- of the Paulistas in Brazil, who are a much- log. Review,” January, 1869, p. 22) an crossed race of Portuguese and Indians, with teresting account ef the success andenergy a mixture of the blood of other races, 190 THE DESCENT OF MAN. [PART Bh holding 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, color and hairiness differ considerably ; as does color to a certain degree, and the shape of the features greatly, in the Negroes of Africa. The shape of the skull varies much in some races ;'“ and so it is with every other character. Now all naturalists have learned by dearly bought experience how rash it is to attempt to define species by the aid of incon- stant characters. But the most weighty of all the arguments against treating the races of man as distinct species is that they graduate into each other, independently in many cases, as far as we can judge, of their having intercrossed. Man has been studied more carefully than any other animal, and yet there is the greatest possible diversity among 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 shows that they graduate into each other, and that it is hardly possible to dis- cover 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 17 For instance with the aborigines of | 18 See a good discussion on this subject @merica and Australia. Prof. Huxley says in Waitz, “Introduct. to Anthropology,” (‘‘ Transact. Internat. Congress of Prehist. Eng. translat., 1863, pp. 198-208, 227. Arch.,” 1868, p. 105) that the skulls of many have taken some of the above statements South Germans and Swiss are ‘‘as short from H. Tuttle’s ‘‘ Origin and Antiquity of and as broad as those of the Tartars,” etc. | Physical Man,” Boston, 1866, p. 35- Ce CHAP, VII} THE RACES OF MAN. "TOI genera of monkeys; while in other genera, as in Cercopithecus, most of the species can be determined with certainty. In the American genus Cebus, the various forms are ranked by some naturalists as species, by others as mere geographical races. Now if numerous specimens of Cebus were collected from all parts of South America, and those forms which at present ap- pear to be specifically distinct were found to graduate inte 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. Neverthe- less, it must be confessed that there are forms, at least in the vegetable kingdom,” which we cannot avoid naming as species, but which are connected together by numberless gradations, in- dependently of intercrossing. Some naturalists have lately employed the term ‘‘sub- species ’’ to designate forms which possess many of the charac- teristics of true species, but which hardly deserve so high a rank. Now if we reflect on the weighty arguments above given, for raising the races of man to the dignity of species, and the insuperable difficulties on the other side in defining them, it seems that the term ‘‘ 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. | Un- fortunately this can rarelv be done: for the larger genera gen. erally include closely ailied forms, which can be distinguished _ only with much difficulty, while the smaller genera within the same family include forms that are perfectly distinct; yet all must be ranked equally as species. So again, species within the same large genus by no means resemble each other to the same degree ; on the contrary, some of them can generally be arranged in little groups round other species, like satellites sound planets.” The question whether mankind consists of one or several species has of late years been much discussed by anthropolo- gists, who are divided into the two schools of monogenists and polygenists. Those who do not admit the principle of evolu- tion must look at species as separate creations, or as in some 19 Prof. Nageli has carefully described some intermediate forms in the Composite several striking cases in his ‘* Botanische of North America. Vattheilurgen,” B. ii., 1866, s. 294-369. Prof. 20 ** Origin of Species,” sth edit., p. 68, Gray has made analogous remarks on 192 THE DESCENT OF MAN. [PART 1, 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 endeavor to decide this point, until some definition of the term ‘‘species’’ is generally ac- cepted ; 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 Amer- ica and Europe, should be ranked as species or geographical races ; and the like holds true of the productions of many isl- ands situated at some little distance from the nearest conti- nent. Those naturalists, on the other hand, who admit the prin- ciple of evolution, and this is now admitted by the majority of rising men, will feel no doubt that all the races of man are de- scended from asingle primitive stock ; whether or not they may think fit to designate the races as distinct species, for the sake of expressing their amount of difference.*! With our do- mestic animals the question whether the various races have arisen from one or more species is somewhat different. Al- though it may be admitted that all the races, as well as all the natural species within the same genus, have sprung from the same primitive stock, yet it is a fit subject for discussion, whether all the domestic races of the dog, for instance, have acquired their present amount of difference since some one species was first domesticated by man; or whether they owe some of their characters to inheritance from distinct species, which had already been differentiated in a state of nature. With man no such question can arise, for he cannot be said to have been domesticated at any particular period. During an early stage in the divergence of the races of man from a common stock, the differences between the races and their number must have been small; consequently, as far as their distinguishing characters are concerned, they then had less claim to rank as distinct species than the existing so-called 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 ex- 83 Sec Prof, Huxley to this effect in the “ Fortnightly Review,” 1865, Pp. 375 J ~ , ee a ee ee ee ee ee a ee ee ee CHAP. ViI.] THE RACES OF MAN. 193 tremely slight, had been more constant than they are at present, and had not graduated 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 offspring of two distinct species for the same object, he some- times induces a considerable amount of convergence, as far as general appearance is concerned. ‘This is the case, as shown 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 anatom- ist, 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 structure among the modified descendants of widely distinct beings. ‘The form of acrystal is determined solely by the mo- lecular forces, and it is not surprising that dissimilar substances should sometimes assume the same form ; but with organic be- ings we should bear in mind that the form of each depends on : an infinity of complex relations, namely, on variations due to causes far too intricate to be followed—on the nature of the variations preserved, these depending on the physical condi- tions, and still 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 had 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, 22 ““Tectures on Man,” Eng. translat., Schweineschidel,” 1864, s. 104. With re- 1864, Pp. 468 spect to cattle, see M. de Quatrefages, 3 “Die Racen des Schweines,” 1860, s. ‘‘ Unité de l’Espéce Humaine,” 1861, p. 119. 46> ‘“‘Vorstudien fiir Geschichte, etc., a (D—Vol. 3 194 THE DESCENT OF MAN. [PART f should ever afterward converge so closely as to lead to a near approach to identity throughout their whole organization. In the case of the convergent races of pigs above refersed to, evi- dence of their descent from two primitive stocks is, according so 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 to.a the gorilla, it can hardly be doubted that marked differ- ences in the structure of certain bones would still be discover- able 1a man as he now exists. Although the existing races of man differ in many respects, gs in colur, hair, shape of skull, proportions of the body, etc., yet, if their whole structure be taken into consideration, they are found ¢o 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 heen independently acquired by aboriginally distinct species or races. ‘The san.e 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 abo- rigines, Negroes, and Europeans are as different from each other in mind as any three races that can be named; yet I was in- cessantly struck, while tiving with the Fuegians on board the Beagle, with the many little traits of character, showing 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 why will read Mr. Tylor’s and Sir J. Lubbock’s interest- ing works* can hardly fail to be deeply impressed with the close similarity between the men of all races in tastes, disposi- tions, and habits) This is shown by the pleasure which they all take in dancing, rude music, acting, painting, tattooing, and otherwise decorating then.selves ; in their mutual comprehension of gesture-language, by the same expression in their features, and by the same inarticulate cries, when excited by the same emotions. This similarity, or rather identity, is striking, when contrasted with the different expressions and cries made by distinct species uf monkeys. There is good evidence that the art of shooting with bows and arrows has not been handed down from any commen progenitor of mankind ; yet, as West- 24 Tylor’s ‘Early History of Menkind,” p. 54. Lubbock’s “ Prehistoric Times,” 26 a86s ; with respect to gesture-languaye, see edit., 1869. : a "= CHAP, VI1.J THE RACES OF MAN, 195 ropp and Nilsson have remarked,® the stone arrow-heads, brought from the most distant parts of the world, and manu- factured 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 archzologisis** with respect to certain widely . prevalent ornaments, such as zigzags, etc.; and with respect to various simple beliefs and customs, such as the burying of the dead under megalithic structures. I reinember observing in South America,” that there, as in so many other parts of the world, men have generally chosen the suinmits of lofty hills to throw up piles of stones, either as a recor! 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 conse- quently 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 bod- ily structure and mental faculties (I do not here refer to sim- ilar 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 separ- ated by the sea, no doubt, preceded any great amount of di- vergence of character in the several races; for otherwise we should sometimes meet with the same race in distinct conti- nents ; and this is never the case. Sir J. Lubbock, after com- paring the arts now practised by savages in all parts of the world, specifies those which man could not have known when he first wandered from his original birthplace; for if once earned they would never have been forgotten.% He thus shows that ‘the spear, which is but a development of the knife- point, and the club, which is but a long hammer, are the only _ 38 “On Analogous Forms of Implements,” * Poa of Ethnological Soc.,” as given ip in ** Memoirs of Anthropolog. Soc.,” by H. ‘Scientific Opinion,” June 2, 1869, p. 3. M. Westropp. ‘‘ The Primitive Inhabitants 27 ** Journal of Researches: Voyage @§ of Scandinavia,” Eng. translat., edited by the Beagle,” p. <6. Sir J. Lubbock, 1868, p. 104. 28 ** Prehistoric Times,” 1869, p. 574 3¢ Westropp, ‘‘On Cromlechs,” etc., 196 THE DESCENT OF MAN. [CART E things left.’’ We adinits, however, that the art of making fire probably had been already discovered, for it is common to al] the races now existing, and was known 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 our earliest ances- tors could have ‘‘ counted as high as ten, considering that so many races now in existence cannot get beyond four.’’ Neyer- theless, at this early period, the inteilectua! 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. From the fundamental differences between certain languages, some philologists have inferred that when man first became widely diffused, he was not a speaking animal; but it may be suspected that languages, far less perfect than any now spoken, aided by gestures, might have been used, and yet have left no traces on subsequent and more highly developed tongues. Without the use of some language, however imperfect, it ap- pears 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 asspecies or sub-species ; but the latter term appears the more appropriate. Finally, we may conclude that when the principle of evolution is generally accepted, as it surely will be before long, the dispute between the monogenists and polygenists will die a silent and unob- served.death. One other question ought not to be passed over without notice, namely, whether, as is sometimes assumed, each sub- t 7 CHAP, VII.] THE EXTINCTION OF RACES. 197 species. or race of man has sprung from a single pair of pro- genitors. With our domestic animals a new race can readily be formed by carefully matching the varying offspring from a single pair, or even from a single individual possessing some new character; but most of our races have been formed, not intentionally from a selected pair, but unconsciously by the preservation of many individuals which have varied, however slightly, in some useful or desired manner. If in one country stronger and heavier horses, and in another country lighter and fleeter ones, were habitually preferred, we may feel sure that two distinct 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, while those which have run wild on the Pampas have acquired larger and coarser heads; and such changes are manifestly due, not to any one pair, but to all the individuals having been subjected to the same conditions, aided, perhaps, by the principle of reversion. ‘The new sub- breeds in such cases are not descended from any single pair, but from many individuals which have varied in different degrees, but in the same general manner ; and we may conclude that the races of man have been similarly produced, the modifications being either the direct result of exposure to different conditions, or the indirect result of some form of selection. But to this latter subject we shall presently return. 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, indi- cate much extinction. Some small and broken tribes, rem- nants 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 thai the rudest living savages ;’’ they must therefore have differed, to a certain extent, from any existing race. The remains de- scribed by Prof. Broca from Les Eyzies, though they unfors %° Translation in “ Anthropological Review,” October, 1868, p. 431: 198 THE DESCENT OF MAN. [PART \ tunately appear to have belonged to a single family, indicate a race with a most singular combination of low or simious, and of high characteristics. ‘This race is ‘‘ entirely different from any other, ancient or modern, that we have ever heard of.’’ It differed, therefore, from the quaternary race of the caverns of Belgium. Man can long resist conditions which appear extremely un- favorable for his existence.*! He has long lived in the extreme regions of the North, with no wood for his canoes or imple- ments, and with only blubber as fuel, and melted snow as drink. In the southern extremity of America the Fuegians survive without the protection of clothes, or of any building worthy to be called a hovel. In South Africa the aborigines wander over arid plains, where dangerous beasts abound. Man can withstand the deadly influence of the Terai at the foot of the Himalaya, and the pestilential shores of tropical Africa. Extinction follows chiefly from the competition of tribe with tribe, and race with race. Various checks are always in ac- tion, serving to keep down the numbers of each savage tribe— such as periodical famines, nomadic habits, and the consequent deaths of infants, prolonged suckling, wars, accidents, sickness, licentiousness, the stealing of women, infanticide, and espe- cially lessened fertility. If any one of these checks increases in power, even slightly, the tribe thus affected tends to decrease ; and when of two adjoining tribes one becomes less numerous and less powerful than the other, the contest is soon settled by war, slaughter, cannibalism, slavery, and absorption. Even when a weaker tribe is not thus abruptly swept away, if it once begins to decrease, it generally goes on decreasing until it becomes extinct.” When civilized 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 civilized 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 wiil 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 30 “Transact. Internat. Congress of Pre- 1 Dr. Gerland ‘‘ Ueber das Aussterben historic Arch.,’’ 1868, pp. 172-175. Seealso der Naturvélker,” 1868, s. 82. Broca (transiation) in ‘‘Anthropological 32 Gerland (ibid., s. 12) gives facts in supe Review,” October, 1868, p. 410. port of this statement. : a CHAP, VII. ] THE EXTINCTION OF RACES. 199 out ;* and so it may be with the evil effects from spirituous liquors, as well as with the unconquerably strong taste for them shown by so many savages. It further appears, mysterious as is the fact, that the first meeting of distinct and separated peo- ple generates disease.*4 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 civilization seems to be a most important element in the success of competing nations. A few centuries ago Europe feared the inroads of Eastern barbarians ; now any such fear would be ridiculous. It is a more curious fact, as Mr. Bagehot has remarked, that savages did not formerly waste away before the classical nations, as they now do before mod- ern civilized 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 potent of all the causes of extinction appears in many cases to be lessened fertility and ill-health, especially among the children, arising from changed conditions of life, notwith- scanding that the new conditions may not be injurious in them- selves. I am much indebted to Mr. H. H. Howorth for hav- ing called my attention to this subject, and for having given me information respecting it. Ihave collected the following cases. When Tasmania was first colonized the natives were roughly estimated by some at 7,000, 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 individ- uals,** who were in 1832 transported to Flinders Island. This island, situated between Tasmania and Australia, is forty miles long, and from twelve to eighteen miles broad: it seems 88 See femarks to this effect in Sir H. _ 35 Sproat, ‘* Scenes and Studies of Savage Holland's ** Medical Notes and Reflections,” Life,’? 1868, p. 284. 1839) P. 390 Rare is, 2 a 86 Bagehot, ‘* Physics and Politics,” ected (‘‘ Journal of Re ‘Fortnightly Review,” April 1, 1868, p. searches: Voyage of the Beagle,” p. 435) 455- a good many cases bearing on this subject; 37 All the statements here given are taken see also Gcilaud (ibid., s. 8). Poeppig from ‘* The Last of the Tasmanians,” by J. speaks of the “breath of civilization as Bonwick, 1870. poisonous to favages,.” 200 THE DESCENT OF MAN. {PART & 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 r11 souls. In 1835 only one hundred were left. As they continued rapidly to decrease, and as they themselves thought that they should not perish so quickly elsewhere, they were removed in 1847 to Oyster Cove, in the southern part of Tasmania. ‘They then consisted (Decem- ber 20, 1847) of fourteen men, twenty-two women, and ten chil. dren.® But the change of site did no good. Disease and decth still pursued them, and in 1864 one man (who died in 1869), and three elderly women alone survived. ‘The infer- tility of the women is even a more remarkable fact than the liability of all 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 civilize the natives. ‘‘ If left tothemselves to roam as they were wont and undisturbed, they would have reared more children, and there would have been less mortality.’? Another careful ov- server 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 Die- men’s Land, and consequent depression of spirits’’ (Bonwick, Pp. 388, 390). Similar facts have been observed in two widely different parts of Australia. The celebrated explorer, Mr. Gregory, told Mr. Bonwick, that in Queensland ‘‘ the want of repro- duction was being already felt with the blacks, even in the most recently settled parts, and that decay would setin.’”’? OF thirteen aborigines from Shark’s Bay who visited Murchison River, twelve died of consumption within three months.* The decrease of the Maories of New Zealand has been care- fully investigated by Mr. Fenton, in an admirable Report, from which all the following statements, with one exception, are taken.” ‘The decrease in number since 1830 is admitted by $8 This is the statement of the Governor ‘*The Last of the Tasmanians,” 1870, py of Tasmania, Sir W. Denison, * Varieties of 386. ‘ Vice-Regal Life,” 1870, vol. i. p. 67. 40 ‘* Observations on the Aboriginal In< 29 For these cases, see Bonwick’s “* Daily habitants of New Zealand,” published by Life of the Tasmanians,” 1870, p. 90; and the Government, 1859. Se cuar. vi.) ZAE EXTINCTION OF RACES. 201 everyone, including the natives themselves, and is still steadily progressing. Although it has hitherto been found impossible to take an actual census of the natives, their numbers were carefully estimated by residents in many districts. The result seems trustworthy, and shows that during the fourteen years previous to 1858 the decrease was 19.42 per cent. Some of the tribes thus carefully examined lived above a hundred miles apart, some on the coast, some inland ; and their means of subsistence and habits differed to a certain extent (p. 28). The total number in 1858 was believed to be 53,700, and in 1872, after a second interval of fourteen years, another census was taken, and the number is given as only 36,359, showing a decrease of 32.29 per cent.!4! Mr. Fenton, after showing in detail the insufficiency of the various causes usually assigned in explanation of this extraordinary decrease, such as new diseases, the profligacy of the women, drunkenness, wars, etc., concludes on weighty grounds that it depends chiefly on the unproductiveness of the women, and on the extraordinary mor- tality of the young children (pp. 31, 34). In proof of this he shows (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 born than males. To this lat- ter point, depending perhaps on a widely distinct cause, I shall return in a future chapter. Mr. Fenton contrasts with aston- ishment the decrease in New Zealand with the increase in Ire- land—countries not very dissimilar in climate, and where the inhabitants now follow nearly similar habits. The Maories themselves (p. 35) ‘‘ attribute their Gecadence, in some meas- ure, to the introduction of new food and clothing, and the attendant change of habits; ’’ and it will be seen, when we con- sider the influence of changed conditions on fertility, that they are probably right. The diminution began between the years 1830 and 1840; and Mr. Fenton shows (p. 40) that about 1830 the art of manufacturing putrid corn (maize), by long steeping in water, was discovered and largely practised ; and this proves that a change of habits was beginning among the natives even when New Zealand was only thinly inhabited by Euro- peans. When I visited the Bay of Islands in 1835, the dress and food of the inhabitants had already been much modified : they raised potatoes, maize, and other agricultural produce, _, & “New Zealand,” by Alex. Kennedy, 1873, p49. — 202 “THE DESCENT OF MAN, {PART & and exchanged 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 neighboring archipelagoes suffered to an extraordinary degree in health, and perished in large numbers, when they were removed to New Zealand, Norfolk Island, and other salubrious places, in order to be educated as 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 subse- quent periods, an accurate census was Officially taken, but I have been able to obtain only the following returns: NaTIVE PopuLaTion. |Annual rate of decrease per cent., assuming it to have (Except during 1832 and! been uniform between the VEAR. 1836, when the few for-|_ successive censuses; these eigners in the islands} censuses being taken at irreg- were included.) ular intervals. 1832. acoccscccscccceces 130, 313 4.46 1826, 1, coptacndvcesenes 108,579 ) f 2.47 FOSS. ccncccceccescacess 71,019 t 0.8f SEROMA Ge wld see Ste iss 67,084 t 2.18 1 Te eee 58,765 J t 2.17 HO72 UE, ahi Ce weet : 51,531 TTY We here see that in the interval of forty years, between 1832 and 1872, the population has decreased no less than sixty- éight per cent.! This has been attributed by most writers to the profligacy of the women, to former bloody wars, and to the severe labor 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 extraordi- 43 “Life of J. C. Patteson,” by C. M. Yonge, 1874, see more especially vol. is D. 530. CHAP, VII.} THE EXTINCTION OF RACES, 203 nary rate of decrease between the years 1832 and 1836; but the most potent of all the causes seems to be lessened fertility. According to Dr. Ruschenberger of the U. S. Navy, who visited these islands between 1835 and 1837, in one district of Hawaii, only twenty-five men out of 1,134, and in another dis- trict only ten out of 637, had a family with 2s many as three children. Of eighty married women, only thirty-nine had ~ ever borne children ; and ‘‘ the official report gives an average of half a child to each married couple in the whole island.’’ This is almost exactly the same average as with the Tasmanians at Oyster Cove. Jarves, who published his History in 1843, says that ‘‘ families who have three children are freed from all taxes; those having more, are rewarded by gifts of land and other encouragements.’’ This unparalleled enactment by the government well shows how infertile the race had become. The Rev. A. Bishop stated in the Hawaiian Sfectator, in 1839, that a large proportion of the children die at early ages, and Bishop Staley informs me that this is still the case, just as in New Zealand. ‘This has been attributed to the neglect of the children by the women, but it is probably in large part due to innate weakness of constitution in the children, in relation to the lessened fertility of their parents. There is, moreover, a further resemblance to the case of New Zealand, in the fact that there is a large excess of male over female births: the census of 1872 gives 31,650 miales to 25,247 females of all ages, that is 125.36 males for every 100 females; whereas :n all civilized 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 tor the increased mortality, especially of the children. The is- lands 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 already abolished, and other changes effected by the king. After this period there was a rapid change in almost all the habits of life of the natives, and they soon became ‘‘the most civilized of the Pacific Islanders.’’ One of my informants, Mr. Coan, who was born on the islands, remarks that the natives have under- gone a greater change in their habits of life in the course of fifty years than Englishmen during a thousand years. From information received from Bishop Staley, it does not appear that the poorer classes have ever much changed their diet, 204 THE DESCENT OF MAN. (PART £.' although many new kinds of fruit have been introduced, 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 alcoholic drinks became very general. Although these changes appear incon- siderable, I can well believe, from what is known with respect to animals, that they might suffice to lessen the fertility of the natives. * Lastly, Mr. Macnamara states“ that the low and degraded inhabitants of the Andaman Islands, on the eastern side of the Gulf of Bengal, are ‘‘ eminently susceptible to any change of climate ; in fact, take them away from their island homes, and they are almost certain to die, and that independently of diet or extraneous influences.’’ He further states that the inhabi- tants of the Valley of Nepal, which is extremely hot in summer, and also the various 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 changed conditions or habits of life, and not exclusively from being transported to a new climate. Mere alterations in habits, which do not appear injurious in themselves, seem to have this same effect ; and in several cases the children are particularly liable to suffer. It has often been said, as Mr. Macnamara remarks, that man can resist with impunity the greatest diversities of climate and other changes ; but this is true only of the civilized races. Man in his wild condition seems to be in this respect almost as suscep- tible as his nearest allies, the anthropoid apes, which have never yet survived long, when removed from their native country. Lessened fertility from changed conditions, as in the case of the Tasmanians, Maories, Sandwich Islanders, and apparently the Australians, is still more interesting than their liability to 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, 43 The foregoing statements are taken chiefly from the following works: ‘* Jarves’s History of the Hawaiian Islands,” 1843, pp. qo0-407. Cheever, ‘‘ Life in the Sandwich slands,” 1851, p. 277. Ruschenberger is quoted by Bonwick, ‘‘ Last of the Tasma- pians,” 1870, p. 378. Bishop is quoted by Sir E. Belcher, *‘ Voyage Round the World,” 1843, vol. i. p. 272. I owe the census of the would sooner or later lead to several years to the kindness of Mr. Coan, at the request of Dr. Youmans, of New York; and in most cases I have compared the Youmans figures with those given in several of the above-named works. I have omitted the census for 1850, as [ have seen two widely different numbers given. 44 *The Indian Medical Gazette,” No vember 1, 1871, P. 240. ‘ / cuar. vit = THE EXTINCTION OF RACES. 205 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 shown that this explana- tion by no means suffices with the New Zealanders, nor does it with the Tasmanians. In the paper above quoted, Mr. Macnamara gives reasons for believing that the inhabitants of districts subject to malaria are apt to be sterile; but this cannot apply in several of the above cases. Some writers have suggested that the aborigines of islands have suffered in fertility and health from long-continued interbreeding ; but in the above cases infertility has coincided too closely with the arrival of Europeans for us to admit this explanation. Nor have we at present any reason to believe that man is highly sensitive to the evil effects of interbreeding, especially in areas so large as New Zealand, and the Sandwich archipelago with its diversified stations. On the contrary, it is known that the present inhabitants of Norfolk Island are nearly all cousins or near relations, as are the Todas in India, and the inhabitants of some of the Western Islands of Scotland ; and yet they seem not to have suffered in fertility.® A much more probable view is suggested by the analogy of the lower animals. The reproductive system can be shown to be susceptible to an extraordinary degree (though why we know not) to changed conditions of life; and this susceptibil- ity leads both to beneficial and to evil results. A large col- lection of facts on this subject is given in chapter xviii. of volume ii. of my ‘‘ Variation of Animals and Plants under Domestication,’’ I can here give only the briefest abstract ; and everyone interested in the subject may consult the above work. Very slight changes increase the health, vigor, and fertility of most or all organic beings, while other changes are known to render a large number of animals sterile. One of the most familiar cases is that of tamed elephants not breeding in India, though they often breed in Ava, where the females are allowed to roam about the forests to some extent, and are thus placed under more natural conditions. ‘The case of various American monkeys, both sexes of which have been kept for many years together in their own countries, and yet have very rarely or “never bred, is a more apposite instance, because of their rela- tionship to man. It is remarkable how slight a change in the #5 On the close relationship of the Norfolk 1873, p. 110. For the Western Islands of Islyaters, see Sir W. Denison, “ Varieties Scotland, Dr. Mitchell, ‘‘ Edinburgh Med& of Vice-Regal Tafe,” vol. i., 1870, p. 410. cai Journal,” March to June, 1865. For the ‘Todas, see Colonel Marshall’s work, | 206 THE DESCENT OF MAN. {PART & conditions often induces sterility in a wild animal when capt: ured; 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 condi- tions with undiminished fertility.“° Certain groups of animals are much more liable than others to be affected by captivity ; and generally all the species of the same group are affected in the same manner. But sometimes a single species in a group is rendered sterile, while the others are not so; on the other hand, a single species may retain its fertility while 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 circum- stanced frequently unite but never produce offspring ; others again produce some offspring, but fewer than in a state of nat- ure; and, as bearing on the above cases of man, it is impor- tant 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 in- habited 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. Civilized 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, Faro- pean dogs in India), yet they are rarely rendered sterile, though a few such instances have been recorded.” The im- munity of civilized races and domesticated animals is probably due to their having been subjected to a greater extent, and therefore having grown somewhat more accustomed, to diversi- fied or varying conditions, than the majority of wild animals ; 46 For the evidence on this head, see 47 * Variation of Animals,” etc., vol i * Variation of Animals,” etc., vol. ii. p. azz. D. iG | | CHAP. ViI.] THE EXTINCTION OF RACES. 207 and to their having formerly immigrated or been carried from country to country, and to different families or sub races hay- ing intercrossed. It appears that a cross with civilized races at once gives to an aboriginal race an immunity from the evil consequences of changed conditions. Thus the crossed off- spring from the Tahitians and English, when settled in Pitcairn Island, increased so rapidly that the island was soon over- stocked; and in June, 1856, they were removed to Norfolk Island. They then consisted of 60 married persons and 134 children, making a total of 194. Here they likewise increased so rapidly that, although sixteen of them returned to Pitcairn Island in 1859, they numbered in January, 1868, 300 souls—the males and females being in exactly equal numbers. What a con- trast does this case present with that of the Tasmanians; the Nor. folk Islanders cxcreased in only twelve and a half years from 194 to 300; whereas the Tasmanians decreased during fifteen years from 120 to 46, of which latter number only ten were children.48 So again in the interval between the census of 1866 and 1872 the natives of full blood in the Sandwich Islands decreased by 8,081, while 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 immi- gration of civilized men. But sterility and ill-health would probably follow, if savages were compelled by any cause, such as the inroad of a conquering tribe, to desert their homes and to change their habits. It is an interesting circumstance that the chief check to wild animals becoming domesticated, which im- plies the power of their breeding freely when first captured, and one chief check to wild men, when brought into contact with civilization, surviving to form a civilized race, is the same, namely, sterility from changed conditions of life. Finally, although the gradual decrease and ultimate extinc- tion of the races of man is a highly complex problem, depend- ing on many causes which differ in different places and at dif- ferent times; it is the same problem as that presented by the extinction of one of the higher animals—of the fossil horse, for 48 These details are taken from ‘*The Commons, May 29, 1863. The following Mutineers of the Bounty,” by Lady Bel- statements about the Sandwich Islanders cher, 1870; and from ‘‘ Pitcairn Island,” are from the ‘ Honolulu Gazette,” and ordered to be printed by the House of from Mr. Coan, 208 THE DESCENT OF MAN. (PART & instance, which disappeared from South America, soon after ward to be replaced, within the same districts, by countiess troops of the Spanish horse. ‘The New Zealander seems con- scious of this parallelism, for he compares his future fate with that of the native rat now almost exterminated by the European rat. ‘Though the difficulty is great to our imagination, and really great, if we wish to ascertain the precise causes and their manner of action, it ought not to be so to our reason, as long as we keep steadily in mind that the increase of each species and each race is constantly checked in various ways; so that if any new check, even a slight one, be superadded, the race will surely decrease in number ; and decreasing numbers will sooner or later lead to extinction; the end, in most cases, being promptly determined by the inroads of conquering tribes. On the Formation of the Races of Man.—In some cases the crossing 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, while 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 gradations may be traced ‘‘ from the black, squat tribes of the mountains to the tall, olive-colored 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 San- talis or Hindoos.® Whether a heterogeneous people, such as the inhabitants of some of the Polynesian islands, formed by the crossing of two distinct races, with few or no pure mem- bers 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 care- ful 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 4° “¢On Anthropology,” meu ee *““An- 52 “The Variation of Animals and Plants thropolog. Review,” Jan.,18 usder Domestication,” vol, ii. p. 95. &@ *“*Annals of Rural Bengal! bs, Pp. 134. OHAP. VII.] THE FORMATION OF RACES. 209 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 color of the skin is the most conspicuous and one of the best marked. It was formerly thought that differences of this kind could be accounted for by long exposure to different climates ; but Pallas first showed that this is not tenable, and he has since been tol- lowed by almost all anthropologists. This view has been re- jected chiefly because the distribution of the variously colored races, most of whom must have long inhabited their present homes, does not coincide with corresponding differences of climate. Some little weight may be given to such cases as that of the Dutch families, who, as we hear on excellent author- ity, have not undergone the least change of color after resid- ing for three centuries in South Africa. An argument on the same side may likewise be drawn from the uniform appearance in various parts of the world of gypsies and Jews, though the uniformity of the latter has been somewhat exaggerated.4 A very damp or a very dry atmosphere has been supposed to be more influential in modifying the color of the skin than mere heat ; but as D’Orbigny in South America, and Livingstone in Africa, arrived at diametrically opposite conclusions with re- spect 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 color of tne skin and hair is sometimes correlated in a surpris- ing manner with a complete immunity from the action of cer- tain 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 afterward 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, 52 Pallas, “ Act. Acad. St. Petersburg,” 1780, part ii. p. 69. He was followed by in S. Africa,” 1857, pp. 338, 329. D’Or- bigny, as quoted by Godron, *‘* De ?Espéce,” Rudolphi, i in his ** Beytrage zur Anthropolo- gie,” 1812. An excellent summary of the evidence is given by Godron, ** De I’ Espéce,” 1859, vol. il. p. 246, etc. Sir Andrew Smith, as quoted by Knox, ** Races of Man,” 1850, Pp: 473- 64 See De Quatrefages on this head, **Revue des Cours Scientifiques,” Oct. 17, 1868, Pp. 731 8’ Livingstone’s “Travels and Researches vol. ii. p. 266. 56 See a paper read before the Royal Soc. in 1813, and published in his Essays in 1818. I have given an account of Dr. Wells’ s views in the Historical Sketch (p. xvi.) to my ** Origin of Species.” Various cases of color correlated with constitutional peculiarities are given in my “ Variation of Animals uns der Domestication,” vol. ii. pp. 227, 335 210 THE DESCENT OF MAN. [PART 1. so destructive in tropical America. They likewise escape to a large extent the fatal intermittent fevers that prevail along at least 2,600 miles of the shores of Africa, and which annually cause one-fifth of the white settlers to die, and another fifth to 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 acclimatization. Pou- chet ® 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 origi- nally brought from various parts of Africa and accustomed to the climate of the West Indies. That acclimatization plays a part, is shown by the many cases in which negroes have be- come somewhat liable to tropical fevers after having resided for some time in a colder climate. The nature of the climate under which the white races have long resided likewise has some influence on them; for during the fearful epidemic of yellow fever in Demerara during 1837, Dr. Blair found that the death-rate of the immigrants was proportional to the lati- tude of the country whence they had come. With the negro the immunity, as far as it is the result of acclimatization, im- plies exposure during a prodigious length of time; for the abo- rigines of tropical America who have resided there from time immemorial are not exempt from yellow fever ; and the Rev. H. B. Tristram states that there are districts in Northern Africa which the native inhabitants are compelled annually to leave, though the negroes can remain with safety. That the immunity of the negro is in any degree correlated with the color of his skin is a mere conjecture: it may be cor- related with some difference in his blocd, nervous system, or other tissues. Nevertheless, from the facts above alluded ia, and from some connection apparently existing between com- plexion and a tendency to consumption, the conjecture seemed to me not improbable. Consequently I endeavored, with but little success," to ascertain how far it holds good. The late 67 See, for instance, Nott and Gliddon, “Types of Mankind,” p. 68. 38 M Major Tulloch, in a paper read before the Statistical Society, April 20, 1840, and iven in the *‘ Atheneum,” 1840, p. 353. 89 “The Plurality of the Human Race” (translat.), 1864, p. ° Quatrefages, ‘ Unité de VEspéce Hu- maine,” 1861, p. 205. Waitz, * Introduct. to Anthropology,” translat., vol. i., 1863, p 194. Livingstone gives analogous cases in his oT; Travels.” 61 In the spring of 1862 I obtained per- mission from the Director-General of the Medical Department of the Army to trans- mit to the surgeons of the various regiments on foreign service a blank table, with the fol- lowing appended remarks, but I have re- ceived noreturns. ‘** As several well-marked cases have been recorded with our domestic animals of a relation between the color of the dermal appendages and the constitution, and it being notorious that there is some limited degree of relation between the cela — CHAP. VII. THE FORMATION OF RACES. 21 Dr. Daniell, who had long lived on the West Coast of Africa, told me that he did not believe in any such relation. € was himself unusually fair, and had withstood the climate in a wonderful manner. When he first arrived as a boy on the coast, an old and experienced negro chief predicted from his appearance that this would prove the case. Dr. Nicholson, of Antigua, after having attended to this subject, writes to me that he does not think that dark-colored Europeans escape the yellow fever more than those that are light-colored. Mr. J. M. Harris altogether denies that Europeans with dark hair withstand a hot climate better than other men: on the con- trary, experience has taught him, in making a selection of men for service on the coast of Africa, to choose those with red hair. As far, therefore, as these slight indications go, there seems no foundation for the hypothesis that blackness has re- sulted 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 chil- dren only six or eight months old are often carried about naked, and are not affected. I have been assured by a medical man that some years ago during each summer, but not during the winter, his hands became marked with light brown patches, like, although larger than freckles, and that these patches were never affected by sun-burning, while the white part- of his of the races of man and the climate in- habited by them, the following investiga- tion seems worth consideration: Namely, whether there is any relation in Europeans between the color of their hair and their liability to the diseases of tropical countries. If the surgeons of the several regiments, when stationed in unhealthy tropical dis- tricts, 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-colored hair, and hair of in- termediate or doubtful tints ; and if a simi- lar account were kept by the same medical gentlemen, of all the men who suffered from malarious and yellow fevers, or from dysen- tery, it would soon be apparent, after some thousand cases had been tabulated, whether there exists any relation between the color of the hair and constitutional liability to tropi- cal diseases. Perhaps no such relation would be discovered, but the investigation is well worth making. In case any positive results were obtained, it might be of some practical use in selecting men for any particular ser- wice. Theoretically the result would be of p. Xxi. high interest, as indicating one means by which a race of men inhabiting from a re- mote period an unhealthy tropical climate, might have become dark-colored by the better preservation of dark-haired or dark- complexioned individuals during a long suc- cession of generations.” 62 ** Anthropological Review,” Jan., 1866, Dr. Sharpe also says, with respect to India (‘* Man a Special Creation,” 1873, p. 118), that ‘‘it has been noticed by some medical officers that Europeans with light hair and florid complexions suffer less from diseases of tropical countries than persons with dark hair and sallow complexions ; and, so far as I know, there appear to be good grounds for this remark.” On the other hand, Mr. Heddle, of Sierra Leone, ‘‘who has had more clerks killed under him than any other man,” by the climate of the West African Coast (W. Reade, ** African Sketch Book,” vol. ii. p. 522), holds a di- rectly opposite view, as does Capt. Burton. 08. 98 Man a Special Creation,” 1873, pe IIQg. : 212 THE DESCENT OF MAN. skin have on several occasions been much inflamed and blis- tered. With the lower animals there is, also, a constitutional difference in liability to the action of the sun between those parts of the skin clothed with white hair and other parts. Whether the saving of the skin from being thus burned is of suf- ficient importance to account for a dark tint having been grad- ually acquired by man through natural selection, [ 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 south- ern parts of the Malay archipelago, just as the lighter-colored Hindoos have resided in India for a shorter time than the darker aborigines of the central and southern parts of the pen- insula. Although with our present knowledge we cannot account for the differences of color in the races of man, through any ad- vantage 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 gen- erally admitted, the European settlers in the United States un- dergo aslight but extraordinarily rapid change of appearance. Their bodies and limbs become elongated; and I hear from Col. Bernys that during the late war in the United States, good evidence was afforded of this fact by the ridiculous ap- pearance presented by the German regiments, when dressed in ready-made clothes manufactured for the American market, and which were much too long for the men in every way. There is, also, a considerable body of evidence showing that in the Southern States the house-slaves of the third generation present a markedly different appearance from the field-slaves.© If, however, we look to the races of man as distributed over the world, we must infer that their characteristic differences cannot be accounted for by the direct action ef different con- [PART & 64 * Variation of Animals and Plants un- der Domestication,” vol. ii, pp. 336, 337. 65 See, for instance, Quatrefages (“ Revue des Cours Scientifiques,” Oct. 10, 1868, p. 724) on the effects of residence in Abyssinia and Arabia, and other analogouscases. Dr. Rolle (‘‘ Der Mensch, seine Abstammung,” etc., 1865, s. 99) states, on the authority of Khanikof, that the greater number of Ger- man families settled in Georgia have ac- quired in the course of two generations dark hair and eyes. Mr. D. Forbes informs me that the Quichuas in the Andes vary sige in color, according to the position of the val- leys inhabited by them. 66 Harlan, ‘* Medical Rese eae Pp. 532. Quatrefages (‘Unité de l’Espéce Humaine,” 1861, p. 128) has collected much evidence on this head. ‘ ” ee CHAP. VII.] THE FORMATION OF RACES, 213 ditions of life, even after exposure to them for an enormous period of time. The Esquimaux live exclusively on animal - food ; they are clothed in thick fur, and are exposed to intense cold and to prolonged darkness ; yet they do not differ in any extreme degree from the inhabitants of Southern China, who live entirely on vegetable food, and are exposed almost naked to a hot, glaring climate. The unclothed Fuegians live on the marine productions of their inhospitable shores ; the Botocudos of Brazil wander about the hot forests of the interior and live chiefly on vegetable productions ; yet these tribes resemble each other so closely that the Fuegians on board the Beagle were mistaken by some Brazilians for Botocudos. ‘The Boto- cudos 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 habit- ually 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 alittle modified. With civilized 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 greater 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 previously adduced case of rabbits) have given to some races an elongated skull of the 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 color of the skin and hair are plainly correlated, as is the texture of the hair with its color in the Mandans of North America.® The color also of the skin, and the odor $7 See Prof. Schaaffhausen, translat. in in ten or twelve of the members, of all ages “Anthropological Review,” Oct., 1868, p. and both sexes, have bright silvery gray 2G. ; hair, which is hereditary. Now this hair is °° Mr. Catlin states (‘*N. American In- as coarse and harsh as that of a horse dians,” 3d edit., 1842, vol.-i. p. 49) that in mane, while the hair of other colors is fine dhe whole tribe of the Mandans, about one and soft, 214 THE DESCENT OF MAN. [PART & emitted by it, are likewise in some manner connected. With the breeds of sheep the number of hairs within a given space and the number of the excretory pores are related. If we may judge from the analogy of our domesticated animals, many modifications of structure in man probably come under 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 whether slight individual differences, to which man is emi- nently lable, may not have been preserved and augmented during a long series of generations through natural selection. But here we are at once met by the objection that beneficial variations alone can be thus preserved; and as far as we are enabled to judge, although always liable to err on this head, none of the differences between the races of man are of any direct or special service to him. ‘The intellectual and moral or social faculties must of course be excepted from this remark. The great variability of all the external differences between the raees of man likewise indicates that they cannot be of much inrportance ; for, if important, they would long ago have been either fixed and preserved, or eliminated. In this respect man resembles those forms, called by naturalists protean or polymorphic, which have remained extremely variable, owing, as it seems, to such variations being of an indifferent nature, and to their having thus escaped the action of natural selec- tion. We have thus far been baffled in all our attempts to account for the differences between the races of man; but there re- mains one important agency, namely Sexual Selection, which appears to have acted powerfully on man, as on many other animals. Ido not intend to assert that sexual selection will account for all the differences between the races. An unex~ plained residuum is left, about which we can only say, in our ignorance, that as individuals are continually born with, for instance, heads a little rounder or narrower, and with noses a little longer or shorter, such slight differences might become fixed and uniform, if the unknown agencies which induced 69 On the odor of the skin, Godron, “Sur the skin, Dr. Wilckens, ** Die Aufgaben deg PEspéce,” tom. ii. p- 217. On the pores in Landwirth. Zootechnik,” 1 3869, S a CHAP. VII} STRUCTURE OF THE BRAIN. 21§ them were to act in a more constant manner, aided by long- continued intercrossing. Such variations come under the pro- visional 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 shown that it would be an inexplicable fact if man had not been modified by this agency, which appears to have acted powerfully on innumerable ani- mals. Itcan further be shown that the differences between the races of man, as in color, hairiness, form of features, etc., are of a kind which might have been expected to come under the influence of sexual selection. But in order to treat this subject properly, I have found it necessary to pass the whole animal kingdom in review. I have therefore devoted to it the Second Part of this work. At the close I shall return to man, and, after attempting to show how far he has been modified through sexual selection, will give a brief summary of the chapters in this First Part. NoTE ON THE RESEMBLANCES AND DIFFERENCES IN THE STRUCTURE AND THE DEVELOPMENT OF THE BRAIN IN MAN AND APES, By Pror. HuXx.Ley, F.R.S. The controversy respecting the nature and the extent of the differences in the structure of the brain in man and the apes, which arose some fifteen years ago, has not yet come to an end, though the subject-matter of the dis- pute is, at present, totally different from what it was formerly. It was originally asserted and reasserted, with singular pertinacity, that the brain of all the apes, even the highest, differs from that of man, in the absence of such conspicuous structures as the posterior lobes of the cerebral hemi- spheres, with the posterior cornu of the lateral ventricle and the 2ippo- campus minor, contained in those lobes, which are so obvious in man. But the truth that the three structures in question are as well developed in apes’ as in human brains, or even better ; and that it is characteristic of all the Primates (if we exclude the Lemurs) to have these parts well de- veloped, stands at present on as secure a basis as any proposition in coms parative anatomy. Moreover, it is admitted by every one of the long series of anatomists who, of late years, have paid special attention to the arrange- ment of the complicated sulci and gyri which appear upon the surface of the cerebral hemispheres in man and the higher apes, that they are dis- posed 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 aman, so that the terminology which applies to the one answers for the other, On this point there is no difference of opinion. Some years since. Prof, Bischoff published a memoir on the cerebral convolutions of man 70 “ Die Grosshirn-Windungen des Menschen ;” ‘“Abhandl der K. Bayerisch Akademie,” Bd. x., 1868. 4 es Menschen Abr ungen der ayerischem 216 THE DESCENT OF MAN. [PART P-) and apes; and as the purpose of my learned colleague was certainly not — to diminish the value of the 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 organization, much nearer than to any other animal, is a well-known fact, disputed by nobody, Looking at the mat- ter from the point of view of organization alone, no one probably would ever have disputed the view of Linnzus, that man should be placed, merely as a peculiar species, at the head of the mammalia and of those apes. Both show, in all their organs, so close an affinity, that the most exact anatomical investigation is needed in order to demonstrate those differences which really exist. So it is with the brains, The brains of man, the orang, the chimpanzee, the gorilla, in spite of all the important differences which they present, come very close to one another” (1. c., pe IOI). There remains, then, no dispute as to the resemblance, in fundamental characters, between the ape’s brain and man’s ; nor any as to the wonder- fully close similarity between the chimpanzee, orang, and man, in even the details of the arrangement of the gyri and sulci of the cerebral hemispheres, Nor, turning to the differences between the brains of the highest apes and that of man, is there any serious question as to the nature and extent of these differences. It is admitted that the man’s cerebral hemispheres are absolutely and relatively larger than those of the orang and chimpanzee ; that his frontal lobes are less excavated by the upward protrusion of the roof of the orbits ; that his gyri and sulci are, as a rule, less symmetri- cally disposed, and present a greater number 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 differences constitute a sharp demarcation between the man’s and the ape’s brain. In respect to the external perpendic- ular fissure of Gratiolet, in the human brain, tor instance, Prof. Turner remarks ;: 7! ; ‘‘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 outward. I saw it in the right hemisphere of a female brain pass more than two inches outward; and in another specimen, also the right hemisphere, it proceeded for four-tenths of an inch outward, and then extended downward as far as the lower margin of the outer surface of the hemisphere. The imperfect definition of this fissure in the majority of human brains, as compared with its remarkable distinctness in the brain of most Quadrumana, is owing to the presence, in the former, of certain superficial, well-marked, secondary convolutions which bridge it over and connect the parietal with the occipital lobe. The cioser the first of these © bridging gyri lies to the longitudinal fissure, the shorter is the externaa parieto-occipital fissure ’’ (1. c., p. 12). The obliteration of the external perpendicular fissure of Gratiolet, there- fore, is not aconstant character of the human brain. On the other hand, its full development is not a constant character of the higher ape’s brain, For, in the chimpanzee, the more or less extensive obliteration of the exe ternal perpendicular sulcus by ‘‘ bridging convolutions,”’ on one side or the other, has been noted over and over again by Prof. Rolleston, Mr. Mars ™2 “ Convolutions of the Human Cerebrum Topographically Considered,” 1866, py ta0/ CHAP, VII.} STRUCTURE OF THE BRAIN, 217 shall, M. Broca, and Prof. Turner. At the conclusion of a special paper on this subject the latter writes : “The three specimens of the brain of a chimpanzee just described, prove that the generalization which Gratiolet has attempted to draw of the complete absence of the first connecting convolution and the conceal- ment of the second, as essentially characteristic features in the brain of this animal, is by no means universally applicable. In only one specimen did the brain, in these particulars, follow the law which Gratiolet has expressed. As regards the presence of the superior bridging convolution, I am inclined to think that it has existed in one hemisphere, at least, in z majority of the brains of this animal which have, up to this time, been figured or described, The superficial position of the second bridging con- volution is evidently less frequent, and has as yet, I believe, only been seen in the brain (A) recorded in this communication. The asymmetrical ar- rangement in the convolutions of the two hemispheres, which previous ob- servers 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 perpen- dicular, 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 Catarrhine or Old World apes, it is never very strongly developed in the New World apes; it is absent in the smaller Platyrhini; rudimentary in P2thecza ,; 78 and more or less obliterated by bridging convolutions in A Zeles, 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 convo- lution of the two sides in the human brain is subject to much individual variation ; and that, in those individuals of the Bushman race who have been examined, the gyri and sulci of the two hemispheres are considerably less complicated and more symmetrical than in the European brain, while in some individuals of the chimpanzee their compiexity and asymmetry be- come notable. This is particularly the casein 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 greater than the difference between the smallest healthy human brain and the largest chimpanzee’s or orang’s brain. Moreover, there is one circumstance in which the orang’s and chim- Ppanzee’s brains resemble man’s, but in which they differ from the lower apes, and that is the presence of two corpora candicantia—the Cynomorpha 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 structure goes, therefore, it is clear that man differs less from the chimpanzee or the orang than these do even from the mons keys, and that the difference between the brain of the chimpanzee and of man is almost insignificant, when compared with that between the chim- panzee brain and that of a Lemur.” ~ 72 Notes more especially on the bridging 7° Flower ‘‘On the Anatomy of Pithecia convolutions in the Brain of the Chimpan- Jfonachus,” ‘ Proceedings of the Zoological zee, ‘‘ Proceedings of the Royal Society of Society,” 1862, E Bdinburgh,” 1865-6, 74 “* Man’s Place in Nature,” p. 102. (J)—Vol. 3 218 THE DESCENT OF MAN. [PART & In the paper to which I have referred, Prof. Bischoff does not den the second part of this statement, but he first makes the irrelevant remar that it is not wonderful if the brains of an orang and a Lemur are very different ; and secondly, goes on to assert that, ‘* If we successively com- pare the brain of a man with that of an orang ; the brain of this with that of achimpanzee ; of this with that of a gorilla, and so on of a Hy/obates, Semnopithecus, Cynocephalus, Cercopithecus, Macacus, Cebus, Callithrix, Lemur, Stenops, /Tapale, we shall not meet with a greater, or even as great a, break in the degree of development of the conyolutions, 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 developnrent of the convolu- tions alone, but to the structure of the whole brain, If Prof. Bischoff had taken the trouble to refer to p. 96 of the work he criticises, in fact, he would have found the following passage: ‘*And it is a remarkable circumstance that though, so far as our present knowledge extends, there zs 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 anc 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 pos- sesses 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 develop- ment of the posterior lobes in the Siamang and in the Howling monkey. Notwithstanding the exceptional brevity of the posterior lobes in these two species, no one will pretend that their brains, in the slightest degree, ap- proach those of the Lemurs. And if, instead of putting Wapale out of its natural place, as Prof. Bischoff most unaccountably does, we write the series of animals he has chosen to mention as follows: Homo, Pithecus, Trog- lodytes, Hylobates, Semnopithecus, Cynocephalus, Cercopithecus, Macacus, Cebus, Callithrix, Hapale, Lemur, Stenops, I venture to reaffirm that the great break in this series lies between Hapale and Lemur, and that this break is considerably greater than that between any other two terms of that series. Prof. Bischoff ignores the fact that long before he wrote, Gratiolet had suggested the separation of the Lemurs from the other Przmates on the very ground of the difference in their cerebral characters ; and that ~ Prof. Flower had made the following observations in the course of his de- scription of the brain of the Javan Loris: ™ ‘**And it is especially remarkable that, in the development of the pos- terior 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 of the Platyrhine group.” So far as the structure of the adult brain is concerned, then, the very considerable additions to our knowledge, which have been made by the researches of so many investigators, during the past ten years, fully justify %6 “Transactions of the Zoological Society,” vol. v., 1862. —— CHAP, VII. STRUCTURE OF THE BRAIN. 219 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 never- theless, in reality, widely different, because they exhibit fundamental dif- ferences 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 con- trary, there is a fundamental agreement in the development of the brain in men and apes, Gratiolet originated the statement that there is a fundamental difference in the development of the brains of apes and that of man—consisting in this ; that, in the apes, the sulci which first make their appearance are situated on the posterior region of the cerebral hemispheres, while, in the human foetus, the sulci first become visible on the frontal lobes.7® 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 fcetus at the 22d or 23d week of utero-gestation, in which Gratiolet notes that the insula was uncovered, but that, nevertheless, ‘‘ des incisures sément le lobe antérieur ; une scissure peu profonde indique la séparation du lobe occipital, trés-réduit d’ailleurs dés cette époque. Le reste de la surface cérébrale est encore absolument lisse.” Three views of this brain are given in Plate IL., figs. 1, 2, 3, of the work cited, showing the upper, lateral, and inferior views of the hemispheres, but not the inner view. It is worthy of note that the figure by no means bears out Gratiolet’s description, inasmuch as tlie fissure (antero-temporal) on the posterior half of the face of the hemisphere, is more marked than any of those vaguely indicated in the anterior half. If the figure is correct, it in no way justifies Gratiolet’s conclusion: ‘‘Il y a donc entre ces cer- veaux [those of a Callithrix and of a Gibbon] et celui du foetus humain une différence fondamentale. Chez celui-ci, longtemps 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. 76 **Chez tous les singes, les plis posté- rieurs se développentles premiers; les plis antérieurs se développent plus tard, aussi la vertébre occipitale et la pariétale sont-elles relativement trés-grandes chez le fcetus. L’Homme présente une exception remarqua- ble quant a l’époque de l’apparition des plis frontaux, qui sont les premiers iudiqués ; mais le développement général du lobe fron- tal, envisagé seulement par rapport a son volume, suit les mémes lois que dans les singes.” Gratioiet, ‘“‘ Mémoire sur les plis cérébraux de l’Homme et des Primates,” p. 39, tab. iv. fig. 3. 77 Gratiolet’s words are (l. ¢., p. 39): “Dans le foetus dont il s’agit les plis céré- braux postérieurs sont bien développés, tan- dis que les plis du lobe frontal sont a peine in- diqués.” ‘The figure, however (PI. iv. fig. 3), shows the fissure of Rolando, and one of the frontal sulci, plainly enough. Neverthe- less, M. Alix, in his ‘* Notice sur Jes travaux anthropologiques de Gratiolet” (“* Mém. de la Societe d’Anthropologie de Paris,’”’ 1868, p. 32), writes thus: “ Gratiolet a eu entre les mains le cerveau d’un fcetus de Gibbon, singe éminemment supérieur, et tellement rapproché de l’orang, que des naturalistes trés compétents l’ont rangé parmi les an- thropoides. M. Huxley, par exemple, n’hésite pas sur ce point. Eh bien, c’est sur le cerveau d’un foetus de Gibbon que Gratiolet a vu les circonvolutions du lobe temporo-sphénoidal déja développées lors- gwil wexiste pas encore de plis sur le lobe frontal. ll était done bien autorise & dire que, chez homme les circonvolutions apparaissent d’a en w, tandis que chez les singes elles se développent d’w en a.”’ 78 “*Ueber die typische Anordnung der Furchen und Windungen auf den Grosshirn- Tdemisphiaren des Menschen und der Affen.” ‘* Archiv fiir Anthropologie,”’ iii., 1868. 7 “ Zur Entwickelungs Geschichte der Furchen und Windungen der Grosshirn- Hemispharen im Foetus des Menschen ‘* Archiv fiir Anthropologie,” iii., 1868. ee ee . — - ? 220 THRE DESCENT OF MAN. [PART L The final results of their inquiries may be summed up as follows: 1. In the human feetus, the Sylvian fissure is formed in the course of the third month of utero-gestation. In this and in the fourth month the cerebral hemispheres are smooth and rounded (with the exception of the Sylvian depression), and they project backward far beyond the cerebellum. 2. The sulci, properly so called, begin to appear in the interval between the end of the fourth and the beginning of the sixth month of foetal life, but Ecker is careful to point out that not only the time, but the order, of their appearance is subject to considerable individual variation, In no case, however, are either the frontal or the temporal sulci the earliest, The first which appears, in fact, lies on the inner face of the hemisphere (whence doubtless Gratiolet, who does not seem to have examined that face in his foetus, overlooked it), and is either the internal perpendicular (occipito-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-pari- etal,’ or “ Fissure of Rolando” is developed, and it is followed, in the course of the sixth month, by the other principal sulci of the frontal, pari- etal, temporal, and occipital lobes. There is, however, no clear evidence that one of these constantly appears before the other; and it is remark- able that, in the brain at the period described and figured by Ecker (I. c., p. 212-13, Taf. II. figs. 1, 2, 3, 4), the antero-temporal sulcus (sctssure paralléle), so characteristic of the ape’s brain, is as well if not better de- veloped than the fissure of Rolando, 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 per- fect harmony with the general doctrine of evolution, and with the view that man has been evolved from some ape-like form ; though there can be no doubt that that form was, in many respects, different from any mem- ber of the Primates now living. Von Baer taught us, half a century ago, that, in the course of their de- velopment, allied animals put on, at first, the characters of the greater groups to which they belong, and, by degrees, assume those which restrict them within the limits of their family, genus, and species ; and he proved, at the same time, that no developmental stage of a higher animal is pre- cisely similar to the adult condition of any lower animal. It is quite cor- rect to say that a frog passes through the condition of a fish, inasmuch as at one period of its life the tadpole has all the characters of a fish, and, if it went no further, would have to be grouped among fishes. But it is equally true that the tadpole is very different from any known fish, In like manner, the brain of a human feetus, at the fifth month, may correctly be said to be not only the brain of an ape, but that of an Arcto- pithecine or marmoset-like ape; for its hemispheres, with their great pos- terior lobes, and with no sulci but the Sylvian and the calcarine, present the characteristics found only in the group of the Arctopithecine Przmates. But itis equally true, as Gratiolet remarks, that, in its widely open Sylvian fissure, it differs from the brain of any actual marmoset. No doubt it would be much more similar to the brain of an advanced foetus of a mar- moset. 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 foetal Cebus Apella, in addition to the Sylvian fissure and the deep calcarine —--- CHAP. VII.) STRUCTURE OF THE BRAIN. 22! fissure, only a very shallow antero-temporal fissure (scissure parallele of Gratiolet). Now this fact, taken together with the circumstance that the antero-tem- poral 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 evi- dence in favor of Gratiolet’s hypothesis, that the posterior sulci appear before the anterior, in the brains of the Platyrhiniz. But it by no means follows that the rule which may hold good for the P/atyrhinz extends to the Catarrhini. We have no information whatever respecting the devel- opment of the brain in the Cyxomorpha : and, as regards the Anthropo- morpha, 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 show that the sulci of a chimpanzee’s, or orang’s, brain do not appear in the same order as a man’s. Gratiolet opens his preface with the aphorism, ‘‘II est dangereux dans les sciences de conclure trop vite.” I fear he must have forgotten this sound maxim by the time he had reached the discussion of the differences between men and apes, in the body of his work. No doubt, the excel- lent author of one of the most remarkable contributions to the just under- standing of the mammalian brain which has ever been made, would have been the first to admit the insufficiency of his data had he lived to profit by the advance of inquiry. The misfortune is that his conclusions have been employed by persons incompetent to appreciate their foundation, as arguments in favor of obscurantism. But it is important to remark that, whether Gratiolet was right or wrong in his hypothesis respecting the relative order of appearance of the tem- poral and frontal sulci, the fact remains that, before either temporal or frontal sulci appear, the foetal brain of man presents characters which are found only in the lowest group of the Primates (leaving out the Lemurs); and that this is exactly what we should expect to be the case, if man has resulted from the gradual modification of the same form as that from which the other Primates have sprung. 80 For example, M. Abbé Lecomte in his terrible pamphlet, “Le Darwinins..’ Joak plme dev Homm e,’” 1873. PART IL SEXUAL SELECTION. CHAPTER VIIL. PRINCIPLES OF 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 selec- tion—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 propor- tional numbers of the two sexes throughout the animal kingdom— The proportion of the sexes in relation to natural selection, WiTH animals which have their sexes separated, the males necessarily differ from the females in their organs of reproduc- tion ; and these are the primary sexual characters. But the sexes often differ in what Hunter has called secondary sexual characters, which are not directly connected with the act of reproduction ; for instance, the male possesses certain organs of sense or locomotion of which the female is quite destitute, or has them more highly developed, in order that he may readily find or reach her ; or again, the male has special organs of prehension ior holding her securely. ‘These latter organs, of infinitely diversified kinds, graduate into those which are commonly ranked as primary, and in some cases can hardly be distinguished from them; we see instances of this in the com- plex appendages at the apex of the abdomen in male insects. Unless indeed we confine the term ‘‘ primary ’’ to the repro- ductive glands, it is scarcely possible to decide which ought ta be called primary and which secondary. CHAP. VIIL] SEXUAL SELECT.ON.. aa. The female often differs from the male in having organs for the nourishment or protection of her young, such as the mam- mary glands of mammals, and the abdominal sacs of the mar- supials. In some few cases also the male possesses similar or- gans, which are wanting in the female, such as the receptacles for the ova in certain male fishes, and those temporarily de- veloped 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 de- fence of the larvs: =nd the community. Many sirnilar cases could be given, but they do not here concern us. ‘There are, however, other sexual differences quite unconnected with the primary reproductive organs, and it is with these that we are more especially concerned—such as the greater size, strength, and pugnacity of the male, his weapons of offence or means of defence against rivals, his gaudy coloring and various orna- ments, his power of song, and other such characters. Besides the primary and secondary sexual differences, suck as the foregoing, the males and females of some animals differ in structures related to different habits of life, and not at all, or only indirectly, to the reproductive functions. Thus the females of certain flies (Culicidze and Tabanidze) are blood- suckers, while the males, living on flowers, have mouths desti- tute of mandibles.‘ The males of certain moths and of some crustaceans (¢.g., Tanais) have imperfect, closed mouths, and cannot feed. The complemental males of certain Cirripedes live like epiphytic plants either on the female or the hermaph- rodite 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 pos- sess. 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 their cocoons. Many female parasitic crustaceans have lost their natatory legs. In some weevil-beetles (Curculionide) 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 structure between the two sexes in relation to different habits of life are generally confined to the lower animals ; but with 2 Westwood, ‘* Modern Class-of Insects,” 2 See Kirby and Spence’s work, “ Intro« vol, ii, 1840, p. 541. Forthe statement about duction to Entomology,” volume iii, 2%. Tanais, wnentioned below, Iam indebted to page . Fritz Miiller. : ONE 224 THE DESCENT OF MAN. [PART IL some few birds the beak of the male differs from that of the female. In the Huia of New Zealand the difference is wonder- fully great, and we hear from Dr. Buller* that the male uses his strong beak in chiselling the larvee of insects out of decayed wood, while 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 propaga- tion of the species: thus a female, which has to nourish a mul- titude of ova, requires more food than the male, and conse- quently requires special means for procuring it. _A male animal which lives for a very short time might lose its organs for pro- curing 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. We are, however, here concerned only with sexual selection, This depends on the advantage which certain individuals have over others of the same sex and species solely in respect of reproduction. When, as in the cases above mentioned, the two sexes differ in structure in relation to different habits of life, they have no doubt been modified through natural selection, and by inheritance limited to one and the same sex. So again the primary sexual organs, and those for nourishing or protect- ing the young, come under the same influence ; for those indi- viduals which generated or nourished their offspring best would leave, ceteris paribus, the greatest number to inherit their superiority, while 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 told 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 antennz modified in an extraordinary manner for the prehension of the female ; hence we may suspect that it is because these animals are 3 “Birds of New Zealand,” 1872, p. 66, . . = CHAP. VIII] SEXUAL SELECTION. 225 washed about by the waves of the open sea, that they require these organs in order to propagate their kind, and if so, their development has been the result of ordinary or natural selection. Some animals extremely low in the scale have been modified for this same purpose; thus the males of certain parasitic worms, when fully grown, have the lower surface of the terminal part of their bodies roughened like a rasp, and with this they coil round and permanently hold the females.4 When the two sexes follow exactly the same habits of life, and the male has the sensory or locomotive organs more highly developed than those of the female, it may be that the per- fection 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 dis- tinction which led me to designate this ferm of selection as Sexual Selection. So again, if the chief service rendered to the male by his prehensile organs is to prevent the escape of the female before the arrival of other males, or when assaulted by them, these organs will have been perfected through sexual selec- tion, that is by the advantage acquired by certain individuals over their rivals. But in most cases of this kind it is impossible to distinguish between the effects of natural and sexual selection. Whole chapters could be filled with details on the differences between the sexes in their sensory, locomotive, and prehensile organs. As, however, these structures are not more interest- ing than others adapted for the ordinary purposes of life, I shall pass them over almost entirely, giving only a few instances under each class. 4M. 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 the differ- ences between the sexes to sexual selection. This distinguished naturalist, therefore, like so many other Frenchmen, has not taken the trouble to understand even the first principles of sexual selection, An English. naturalist insists that the claspers of certain male animals could not have been developed through the choice of the female! Had I not met with this remark, I should not have thought it possible for any one to have read this chapter and to have imagined that I maintain that the choice of the female had anything to do with the development of the prehensile organs in the male ! 226 THE DESCENT OF MAN. [PART 11, 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—thcir various ornaments—their contrivances for producing vocal or instrumental music—and their glands for emitting odors, 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 un- armed, 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 ‘emales, which are unarmed and unornamented, are able to survive and procreate their kind. Secondary sexual characters of the kind just referred to will be fully discussed in the following chapters, as being in many respects interesting, but especially as depend- ing on the will, choice, and rivalry of the individuals of either sex. When we behold two males fighting for the possession of the female, or several male birds displaying their gorgeous plumage, and performing strange antics before an assembled body of females, we cannot doubt that, though led by instinct, they know what they are about, and 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 cock-pit, so it appears that the strongest and most vigorous males, or those provided with the best weapons, have prevailed under nature, and have !ed to the improvement of the natural breed or species. A slight degree of variability leading to some ad- vantage, however slight, in reiterated deadly contests would suffice for the work of sexual selection ; and it is certain that secondary sexual characters are eminently variable. Just as man can give beauty, according to his standard of taste, to his male poultry, or more strictly can modify the beauty originally ~ acquired by the parent species, can give to the Sebright ban- tam a new and elegant plumage, an erect and peculiar carriage —so it appears that female birds in a state of nature have, by a long selection of the more attractive males, added to their beauty or other attractive qualities. No doubt this implies powers of discrimination and taste on the part of the female which will at first appear extremely improbable; but, by the facts to be adduced hereafter, I hope to be able to show CHAP. VIIT.} SEXUAL SEZECTION. 227 that the females actually have these powers. When, however, it is said that the lower animals have a.sense of beauty, it must not be supposed that such sense is comparable with that of a cultivated man, with his multiform and complex associated ideas. A more just comparison would be between the taste for the beautiful in animals, and that in the lowest savages, who admire and deck themselves with any brilliant, glittering, or curious object. From our ignorance on several points, the precise manner in which sexual selection acts is somewhat uncertain. Neverthe- less, if those naturalists who already believe in the mutability of species will read the following chapters, they will, I think, agree with me that sexual selection has played an important part in the history of the organic world. It is certain that among almost all animals there is a struggle between the males for the possession of the female. This fact is so notorious that it would be superfluous to give instances. Hence the females have the opportunity of selecting one out of several males, on the supposition that their mental capacity suffices for the exer- tion of a choice. In many cases special circumstances tend to make the struggle between the males particularly severe. Thus the males of our migratory birds generally arrive at their piaces of breeding before the females, so that many males are ready to contend for each female. Iam informed by Mr. Jenner Weir that the bird-catchers assert that this is invariably the case with the nightingale and blackcap, and with respect to the latter he can himself confirm the statement. Mr. Swaysland, of Brighton, has been in the habit, during the last forty years, of catching our migratory birds on their first arrival, and he has never known the females of any species to arrive before their males. During one spring he shot thirty-nine males of Ray’s wagtail (Budytes Raii) before he saw a single female. Mr. Gould has ascertained, by the dissection of those snipes which arrive the first in this - country, that the males come before the females. And the like holds good with most of the migratory birds of the United States.5 The majority of the male salmon in our rivers, on coming up from the sea, are readv 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 papal state, so that they generally abound for a time ® J. A. Allen, on the ‘‘Mammals and Winter Birds of Florida,” Bull. Comp. Zool- ogy, Harvard College, p. 268. 228 THE DESCENT OF MAN. [PART 11, 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 an- nually first migrated into any country, or which in the spring were first ready to breed, or were the most eager, would leave the largest number of offspring; and these would tend to inherit similar instincts and constitutions. It must be borne in mind that it would have been impossible to change very ma- terially 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 all animals, in which the sexes are separate, there is a constantly recurrent struggle between the males for the posses- sion of the females. Our difficulty in regard to sexual selection lies in under- standing how it is that the males which conquer other males, or those which prove the most attractive to the females, leave a greater number of offspring to inherit their superiority than their beaten and less attractive rivals. Unless this result does follow, the characters which give to certain males an advantage over others could not be perfected and augmented through sexual selection. When the sexes exist in exactly equal num- bers, 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. From various facts and considerations, I formerly inferred that with most animals in which secondary sexual characters are well developed the males considerably exceeded the females in number ; but this is not by any means always true. If the males were to the females as two to one, or as three to two, or even in a somewhat lower ratio, the whole affair would be simple; for the better-armed or more attractive males would leave the largest number of offspring. But after investigating, as far as possible, the numerical pro- portion of the sexes, I do not believe that any great inequality in number commonly exists. In most cases sexual selection appears to have been effective in the following manner. 6 Even with those plants in which the sexes time, so that they cannot be self-fertilized. are separate, the male flowers are generally Now in such flowers, the pollen is in gen- mature before the female. As first shown eral matured before the stigma, though there by C. K. Sprengel, many hermaphrodite are exceptional cases in which the female gine are dichogamous; that is, their male organs are beforehand. : and female organs are not ready at the same CHAP, VIII.] SEXUAL SELECTION. 229 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 individ- uals, and the other of the less vigorous and healthy. The for- mer, 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 vigor- ous, best-nourished, 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 females ; the strongest, and with some species the best armed, of the males drive away the weaker; and the former would then unite with the more vigorous and_better-nourished females, because they are the first to breed.8 Such vigorous pairs would surely rear a larger number of offspring than the retarded females, which would be compelled to unite with the conquered and less powerful males, supposing the sexes to be numerically equal; and this is all that is wanted to add, in the course of successive generations, to the size, 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 pairing with, the more orna- mented 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 observa- tion. Thus the more vigorous females, which are the first to breed, will have the choice of many males; and, though they may not always select the strongest or best armed, they will select those which are vigorous and well armed, and in other respects the most attractive. 7 Here is excellent evidence on the char- acter of the offspring from an experienced ornithologist. Mr. J. A. Allen, in speaking ¢“* Mammals and Winter Birds of E. Flori- da,” p. 229) of the later broods, after the z 248 THE DESCENT OF MAN. [PART IL ing 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, while variations which first appear early in life in either scx tend to be developed in both sexes. I am, however, far from supposing that this is the sole deter- mining cause. As J 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 gained. On the other hand, after this power has been gained and the sexes have come to differ in constitution, the gemmules (if I may again use the language of pangenesis) which are cast off from each varying part in the one sex. would be much more likely to possess the proper affin- ities for uniting with the tissues of the same sex, and thus be- coming 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, amphibians, and fishes; also with many crustaceans, spiders, and some few insects, such as certain orthoptera and libellule. In all these cases the variations, through the accu- mulation of which the male acquired his proper masculine char- acters, must have occurred at a somewhat late period of life ; otherwise the young males would have been similarly charac- terized ; 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 sule, during youth. But there is here room for doubt, for characters are sometimes transferred to the offspring at an ear- lier age than that at which they first appeared in the parents, so that the parents may have varied when adult, and have transferred their characters to their offspring while young. There are, moreover, many animals in which the two sexes closely resemble each other, and yet both differ fam the:r | % j ; B ‘ ‘CHAP, VIII.J SEXUAL SELECTION. 249 young ; and here the characters of the adults must have been acquired late in life; nevertheless, these characters, in appar- ent contradiction to our rule, are transferred to both sexes. We must not, however, overlook the possib@ity, or even prob- abilty, of successive variations of the same nature occurring, under exposure to similar conditions, simultaneously in both sexes at a rather late period of life; and in this case the vari- ations would be transferred to the offspring of both sexes at 6 corresponding late age ; and there would then be no real contra- diction to the rule that variations occurring late in life are trans- ferred exclusively to thesex in which they first appeared. This latter rule seems to hold true more generally than the second one, namely, that variations which occur in either sex early in life tend to be transferred to bothsexes. As it was obviously impos- sible even to estimate in how large a number of cases through- out 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 family. In all the species but one the horns are developed only in the males, though certainly transmitted through the females, and capable of abnormal development in them. In the reindeer, on the other hand, the female is provided with horns ; so that in this species the horns ought, according to our rule, to appear early in life, long before the two sexes are mature and have come to differ much in constitution. In all the other species the horns ought to appear later in life, which would iead to their development in that sex alone in which they first appeared in the progenitor of the whole Family. Now in seven species, belonging to distinct sections of the family and inhabiting different regions, in which the stags alone bear horns, I find that the horns first appear at periods varying from nine months after birth in the roebuck, to ten, twelve, or even more months, in the stags of the six other and larger species. But with the reindeer the case is widely dif- ferent ; for, as I hear from Prof. Nilsson, who kindly made special inquiries for me in Lapland, the horns appear in the young animals within four or five weeks after birth, and at the 8° Tam much obliged to Mr. Cupples for ‘ h obl Cervus alces of N. America, see ‘* Land and having made inquiries for me in regard to Water,’’ 1868, pp. 221 and 254; and for the the Roebuck and Red Deer of Scotland from Mr. Robertson, the experienced head forest- er to the Marquis of Breadalbane. In re- d to Fallow-deer, I have to thank Mr. yton and others for information. For the C. Virginianus and strongyloceros of the same continent, see J. D. Caton, in “ Otta- wa Acad. of Nat. Sc.” 1868, p. 13. For Cervus Eldi of Pegu, see Lieut, Beavan, “Proc. Zoolog. Soc.” 1867, p. 762. > 250 THE DESCENT. OF MAN. (PART Tr. same time in both sexes. So that here we have a structure, developed at a most unusually early age in one species of the family, and likewise common to both sexes in this one’ species alone. In several kinds of antelopes, only the males are provided with horns, while in the greater number both sexes bear horns. With respect to the period of development, Mr. Blyth informs me that there was at one time in the Zoological Gar- dens a young koodoo (Avt. strepsiceros), of which the males alone are horned, and also the young of a closely allied species, the eland (Axz¢. ‘oreas), in which both sexes are horned. Now it is in strict conformity with our rule, that in tne young male koodoo, although ten months old, the horns were remarkably small, considering the size ultimately attained by them ; while in the young male eland, although only three months old, the horns were already very much larger than in the koodoo. It is also a noticeable fact that in the 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 py the males alone, this species is in an intermediate condi- tion, and the horns do not appear until about five or six months atter birth. Therefore, in comparison with what little we know of the development of the horns in other antelopes, and from what we do knuw with respect to the horns of deer, cattle, etc., those of the prong-horned antelope appear at an intermediate period of lite—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 afterward.44 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 inquiry “ that the horns are developed later in life in this breed than in ordinary. 40 Antilocapra Americana. I have to. 421 am greatly indebted to Prof. Victor thank Dr. Canfield for information with re- Carus for having made inquiries for me, spect to the horns of the female : see alsohis - from the highest authorities, with respect paper in ‘t Proc. Zoolog. Soc.” 1866, p. 109. Also Owen, ‘‘ Anatomy of Vertebrates,” vol. lii. p. 627. 41 T have been assured that the horns of the sheep in North Wales can always be felt, and are sometimes even an inch in length, at birth. Youatt says (‘‘ Cattle,” 1834. p. 277), that the prominence of the frontal bone in cattle penetrates the cutis at birth, and pet the horny matter is soon formed over t to the merino sheep of Saxony. On the Guinea coast of Africa there is, however, a breed of sheep in which, as with merinos, the rams alone bear horns; and Mr.. Winwood Reade informs me that in one case observed by him a young ram, born on Feb. roth, first showed horns on March 6th, so that in this instance, in conformity with rule, the development of the horns occurred at a latet. period of life than in Welsh sheep, in which both sexes are horned. : CHAP. VIIt.} SEXUAL SELECTION. 255° 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 birds, and he comes to the following conclusion: that with those species in which they are confined to the males they are developed late in life ; whereas with those species in which they are common to the two sexes, they are developed at a very early period. This is certainly a striking confirmation of my two laws of inheritance. In most of the species of the splendid family of the Pheas- ants, the males differ conspicuously from the females, and they acquire their ornaments.at arather late period of life. The eared pheasant (Crossoptilon auritum), however, offers a re- markable 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 with our rule, these do not begin to be de- veloped before the age of six months, as I am assured by Mr. Bartlett, and even at this age the two sexes can hardly be dis- tinguished:“ , The male and female Peacock differ conspicu- ously 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 some- what smaller in the female, and it is developed early in life, while the curled tail-feathers and other ornaments of the male are developed later.” Between such extreme cases of close 43 ** Ueber die knéchernen Schadelhécker der Vogel,” in the ‘“‘ Niederlandischen Ar- chiy fiir Zoologie,” Band I. Heft 2, 1872. 44 In the common peacock (Pavo crista- tus) the male alone possesses spurs, while both sexes of the Java peacock (P. muticus) offer the unusual case of being furnished with spurs. Hence I fully expected that in the latter species they would have been de- veloped earlier in life than in the common Ss ; but M. Hegt of Amsterdam in- rms me that with young birds of the Previous year, of both species, compared on April 23, 1869, there was no difference in the development of the spurs. The spurs, however, were as yet represented merely by slight knobs or elevations. I presume that I should have been informed if any difference in the rate of development had been ob- served subsequently. 45 In some other species of the Duck family the speculum differs in a greater de- gree in the two sexes; but I have not been able to discover whether its full development occurs later in life in the males of such species than in the male of the common 252 THE DESCENT OF MAN. {PART IL sexual resemblance and wide dissimilarity as those of the Crossoptilon and peacock, many intermediate ones could be given, in which the characters follow our two rules in their order of development. As most insects emerge from the pupal state in a mature con- dition, it is doubtful whether the period of development can determine the transferrence of their characters to one or to both sexes. But we do not know that the colored scales, for in- stance, in two species of butterflies, in one of which the sexes differ in color, while 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 colored marks are confined to one sex, while others are common to both sexes. A difference of this kind in the period of development is not so improbable as it may at first appear; for with the Orthoptera, which assume their adult state not by @ single metamorphosis, but by a succession of moults, the young males of some species at first resemble the females, and acquire their distinctive masculine characters only at a later moult. Strictly analogous cases occur at the successive moults of certain male crustaceans. We have as yet considered the transferrence of characters, relatively to their period of development, only in species in a natural state ; we will now turn to domesticated animals, and first touch on monstrosities and diseases. The presence of supernumerary digits, and the absence of certain phalanges, must be determined at an early embryonic period—the ten- dency to profuse bleeding is at least congenital, as is probably color-blindness—yet these peculiarities, and other similar ones, are often limited in their transmission to one sex ; so that the rule that characters developed at an early period tend to be transmitted to both sexes, here wholly fails. But this rule, as before remarked, does not appear to be nearly so general as the | converse one, namely, that characters which appear late in life in one sex are transmitted exclusively to the same sex. From the fact of the above abnormal peculiarities becoming attached to one sex long before the sexual functions are active, we may duck, as ought to be the case according to our rule. With the allied Mergus cuculla- ¢#us we have, however, 2 case of this kind : the two sexes differ conspicuously in general the young males at first entirely resemble the females, and have a erayishewiee speculum, which becomes pure white at an earlier age than that at which the adult male acquires pkimage, and to a_ sonsiderable degree in tae speculum, which is pure white in_ the male and grayish-white in the female. Now his other and more strongly marked sex differences ; see Audubon, “ Ornithologieal Biography,” vol. ii. 1835, pp. 249-250- + CHAr, ¥211.} SHXUAL SELECTION, — 253 infer that there must be some difference between thesexes at an extremely early age. With respect to sexually limited diseases, we know too little of the period at which they originate, to draw any safe conclusion. Gout, however, seems to fall under our rule, for it is generally caused by intemperance during ‘manhood, and is transmitted from the father to his sons in a much more marked manner 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 development of their horns, forehead, mane, dewlap, tail, and hump on the shoulders ; and these peculiarities, in accordance with our rule, are not fully developed until a rather late period of life. The sexes of dogs do not differ, except that in certain breeds, especially in the Scotch deer-hound, the male is much larger and heavier than the female ; and, as we shall see in a fut- ure chapter, the male goes on increasing in size to an unusually late period of life, which, according to rule, will account for his increased size being transmitted to his male offspring alone. On the other hand, the tortoise-shell color, which is confined to female cats, is quite distinct at birth, and this case violates the rule. There is a breed of pigeons in which the males alone are streaked with black, and the streaks can be detected even in the nestlings ; but they become more conspicuous at each suc- cessive moult, so that this case partly opposes and partly sup- ports 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 fol- lowing 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 pe- riod ; 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 color 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 char- acters by one or both sexes seems generally determined by the 4° ~ Das Ganze der Taubenzucht,” 1837, s. eons, see Dr. Chapuis, ‘Le pigeon voy %t, <4. For she case of the streaked pig- ageur Belge,” 1865, p. 87. 254 THE DESCENT OF MAN. (PART 1, period at which such characters are developed. Thus in all the many breeds in which the adult male differs greatly in color from the female, as well as from the wild parent-species, he differs also from the young male, so that the newly acquired characters must have appeared at a rather late period of life. On the other hand, in most of the breeds in which the two sexes resemble each other, the young are colored in nearly the same manner as their parents, and this renders it probable that their colors 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 transferrence to both sexes ; for the males alone of many natural species are either black or white, the females be- ing differently colored. 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 colored in nearly the same manner. ‘The laced plumage of the Sebright bantam is the same in both sexes, and in the young chickens the wing-feathers are distinctly, though imperfectly, laced. Spangled Hamburgs, however, offer a partial exception ; for the two sexes, though not quite alike, resemble each other more closely than do the sexes of the aboriginal parent-species ; yet they acquire their characteristic plumage late in life, for the chickens are distinctly pencilled. With respect to other char- acters besides color, 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 de- veloped 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 won- derfully early age, of which curious proofs could be given ; and this character is transmitted to both sexes, so that the hens, from their extreme pugnacity, are now generally ex- hibited in separate pens. With the Polish breeds the bony protuberance of the skull which supports the crest is partially developed even before the chickens are hatched, and the crest itself soon begins to grow, though at first feebly ; “ and in this breed the adults of both sexes are characterized by a great bony protuberance and an immense crest. 47 For full particulars and references on 256. In regard to the higher animals, the ail these points respecting the several breeds sexual differences which have arisen under of the Fowl, see ‘Variation of Animals and domestication are described in the samg Plants under Domestication,” vol, i. pp. 25g work under the head of each species. — . iia oop 9 CHAP, VIII.} SEXOCAL SELECTION. 255 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 man- ner of their transmission—for example, the striking fact of the early growth of the horns in the reindeer, in which both sexes bear horns, in comparison with their much later growth in the other species in. which the male alone bears horns—we may conclude that one, though not the sole, cause of characters being exclusively inherited by one sex is their development at alate 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, while the sexes differ but little in constitution. It appears, however, that some difference must exist between the sexes even during a very early embry- onic period, for characters.developed at this age not rarely become attached to one sex. Summary and Concluding Remarks.—¥rom the foregoing discussion on the various laws of inheritance, we learn that the characters of the parents often, or even generally, tend to be- come developed in the offspring of the same sex at the same - age, and periodically at the same season of the year, in which they first appeared in the parents. But these rules, owing to unknown causes, are far from being fixed. Hence, during the modification of a species, the successive changes may readily be transmitted in. different ways; some to one sex, and some to both ; some to the offspring at one age, and some to the offspring at all ages. Not only are the laws of inheritance extremely complex, but so are the causes which induce and govern variability. The variations thus induced are preserved and accumulated by sexual selection, which is in itself an extremely complex affair, depending, as it does, on the ardor 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 toward 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 256 THE DESCENT OF MA V. [PART at period of life in one sex or in both, and be transmitted to both sexes at all ages, and then all the individuals of the species are similarly modified. In the following chapters it will be seen that all these cases frequently occur in nature. Sexual selection can never act on any animal before the age for reproduction arrives. rom 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 hold- ing the female, and for exciting or charming her. When the sexes differ in these respects, it is also, as we have seen, an extremely general law that the adult male differs more or less from the young male; and we may conclude from this fact that the successive variations by which the adult male became modified did not generally occur much before the age for reproduction. Whenever some or many of the variations oc- curred early in life, the young males would partake more or less of the characters of the adult males ; and differences of this kind between the old and young males may be 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— as by acquiring bright colors, which would render them con- spicuous to their enemies, or by acquiring structures, such as great horns, which would expend much vital force in their development. Variations of this kind occurring in the young males would almost certainly be eliminated through natural selection. With the adult and experienced males, on the othe: hand, the advantazes derived from the acquisition of such characters would more than counterbalance some exposure te danger, and some loss of vital force. As variations which give to the male a better chance of con- quering other males, or of finding, securing, or charming the opposite sex, would, if they happened to arise in the female, be of no service to her, they would not be preserved in her through sexual selection. We have also good evidence with domesticated animals that “variations of all kinds are, if not carefully selected, soon lost through intercrossing and acciden- tal deaths. Consequently, in a state of nature, if variations of the above kind chanced to arise in the female line, and to be transmitted exclusively in this line, they would be extremely liable to be lost. If, however, the females varied and trans- cuap. vi} SEXUAL SELECTION. 257 mitted their newly acquired characters to their offspring of both sexes, the characters which were advantageous to the males would be preserved by them through sexual selection, and the two sexes would in consequence be modified in the same manner, although such characters were of no use to the females ; but I shall hereafter have to recur to these more intricate con- _ tingencies. . Lastly, the females may acquire, and apparently have often acquired by transferrence, characters from the male Sex. As variations occurring late in life, and transmitted to one sex alone, have incessantly been taken advantage of and accu- mulated through sexual selection in relation to the reproduc- tion of the species; therefore it appears, at first sight, an unaccountable fact that similar variations have not frequently been accumulated through natural selection, in relation to the ordinary habits of life. If this had occurred, the two sexes would often have been differently modified, for the sake, for instance, of capturing prey or of escaping from danger. Dif- ferences of this kind between the two sexes do occasionally occur, especially in the lower classes. But this implies that the two sexes follow different habits in their struggles for existence, which is a rare circumstance with the higher animals. The case, however, is widely different with the reproductive fune- tions, in which respect the sexes necessarily differ. For varia- tions in structure which are related to these functions have often proved of value to one sex, and, from having arisen at a late period of life, have been transmitted to one sex alone; and such variations, thus preserved and transmitted, have given rise to secondary sexual characters. In the following chapters I shall treat of the secondary sex- ual characters in animals of all classes, and shall endeavor in each case to apply the principles explained in the present chap- ter. The lowest classes will detain us for a very short time, but the higher animals, especially birds, must be treated at considerable length. It should be borne in mind that, for reasons already assigned, I intend to give only a few illustra- tive 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 wayé the most interesting. 258 THE DESCENT OF MAN. (PART ™ Supplement on the Proportional Numbers of the Two Sexes tii 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 king- dom, I will here give such materials as I have been able to coi- lect, 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 cer- tainty 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 born alive yearly was 707,120, in the proportion of 104.5 males to 100 females. But in 1857 the male births throughout England were as 105.2, and in 1865 as 104.0 to 100. Looking to separate districts, in Bucking- hamshire (where about 5,000 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; while in North Wales (where the average annual births are 12,873) it was as high as 106.2 to 100. ‘Taking a still smaller district, viz., Rutlandshire (where the annual births average only 739), in 1864 the male births were as 114.6, and in 1862 as only 97.0 to 100; but even in this small district the average of the 7,385 births, during the whole ten years, was as 104.5 to 100; that is in the same ratio as throughout England.® ‘The pro- portions are sometimes slightly disturbed by unknown causes ; thus Prof. Faye states ‘‘ that in some districts of Norway there has been during a decennial period a steady deficiency of boys, while 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 births have exceeded the males. In Russia the average proportion is as high as 108.9, and in Philadelphia, in the United States, as 110.5 to 100. The average for Europe, de- duced by Bickes from about seventy million births, is 106 48 “*T'wenty-ninth Annual Report of the nuaire pour l’An 1867,” p. 213. For Philadel- Registrar-General for 1866.” In this report phia, Dr. Stockton-Hough, ** Social Science (p. xii.) a special decennial table is given. Assoc.” 1874. For the Caje of Good Hope, 49 For Norway and Russia, see abstract Quetelet as quoted by Dr. H. H. Zouteveen, of Prof. Faye’s researches, in ‘‘ British and in the Dutch translation of this work (vol. i Foreign Medico-Chirurg. Review,” April, P- 417), where much information is given o@ 3867, pp. 343> 345- a or France, the “An- the praportion of the sexes. _ PROPORTION OF THE SEXES. 259 males to 100 females. On the other hand, with white chil- dren born at the Cape of Good Hope, the proportion of males is so 10w as to fluctuate during successive years between go and 99 males for every 100 females. It is a singular fact that with Jews the proportion of male births is decidedly larger than with Christians: thus in Prussia the proportion is as 113, in Breslau as 114, and in Livonia as 120 to 100; the Christian births in these countries being the same as usual, for instance, in Livonia as 104 to 100. Prof. Faye remarks that, ‘a still greater preponderance of males would be met with if death struck both sexes in equal proportion in the womb and during birth. But the fact is, that for every 100 still-born females, we have in several countries from 134.6 to 144.9 still-born males. During the first four or five years of life, also, more male children die than females ; forexample, in England, dur- ing the first year, 126 boys die for every 100 girls—a propor’ tion which in France is still more unfavorable.’’* = Dr. Stockton-Hough accounts for these facts in part by the more frequent defective development of males than of females. We have before seen that the male sex is more variable in struct- ure than the female ; and variations in important organs would generally be injurious. But the size of the body, an 1 especially of the head, being greater in male than female infants is an- other 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 competent 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 subsequently, and owing to the exposure of grown men to various dangers, and to their tendency to emigrate, the females in all old-settie countries, where statistic2! records have been kept, are found to preponderate considerably over the males. BAP. VIII.) 50 In regard to the Jews, see M. Thury, “La Loi de Production des Sexes,” 1863, P25. ; $1 “ British and Foreign Medico-Chirurg. Review,” April, 1867, p. 343. Dr. Stark also remarks (‘Tenth Annual Report of Births, Deaths, etc., in Scotland,” 1867, p. xxvill.) that ‘These examples may suffice to show that, at almost every stage of life, the males in Scotland have a greater liability to death anda higher death-rate than the females. The fact, however, of this pecu- liarity being most strongly developed at that infantile period cf life when the dress, food, end general treatment of both sexes are seems to prove that the higher male death-rate is an impressed, natural, and constitutional peculiarity due to sex alone.” 52 «West Riding Lunatic Asylum Re- orts,” vol. i. 1871, p. 8. Sir J. Simpson fina proved that the head of the male infant exceeds that of the female by three-eighths of an inch in circumference, and by one- eighth in transverse diameter. Quetelet has shown that woman is born smaller than man ; see Dr. Duncan, ‘‘Fecundity, Fertility, Sterility.”’ 1871, p. 382. 53 With the savage Guaranys of Paraguay, according to the accurate Azara (*‘ Voyages dans lAmerique mérid.” tom. ii. 1809, Pp) 60, 17y), the women are to the men in proportion of 14 to 13. 260 THE DESCENT OF MAN, (PART IL It seems at first sight a mysterious fact that in different na- tions, under different conditions and climates, in Naples, Prus- sia, 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 ex- plained by different writers in many different ways, as from the mothers being generally young, from the large proportion of first pregnancies, etc. But we have seen that male infants, from the large size of their heads, suffer more than female in- fants during parturition, and as the mothers of illegitimate children must be more liable than other women to undergo bad labors, from various causes, such as attempts at concealment by tight lacing, hard work, distress of mind, etc., their male in- fants would proportionably suffer. And this probably is the most efficient of all the causes of the proportion of ‘males to females born alive being less among illegitimate childten than among the legitimate. With. most animals the greater size of the adult male than of the femaie is due to the stronger males having conquered the weaker in their struggles for the posses- sion of the females, and no doubt it is owing to this fact that the two sexes of at least some animals differ in size at birth. Thus we have the curious fact that we may attribute the more frequent deaths of male than female infants, especially among 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. Leuck- art © has advanced what he considers sufficient evidence, with respect to man and certain domesticated animals, that this is one important though not the sole factor in the result. So again the period of impregnation relatively to the state of the female has been thought by some to be the efficient cause; but recent observations discountenance this belief. According to Dr. Stockton-Hough,® the season of the year, the poverty or wealth of the parents, residence in the country or in cities, the crossing of foreign immigrants, etc., all influence the propor- tion 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 sub- ject in the harems of Siam, and concludes that the proportion 84 Babbage, ‘‘ Edinburgh Journal of Sci- | 55 Leuckart (in Wagner “ Handwortere ence,” «82y, vol. i. p. 88; also p. 90, on buch der Phys.” B. iv, 1853, S- 774+ still-born children. On illegitimate children 58 Social Science Assoc, of Phila., 1874. fa England, see ‘Report of Registrar- 57 ‘‘ Anthropulogical Review,” April, ga General for 266,” p. xv. D+ CVille ~. ‘CHAP. vi] PROPORTION OF THE SEXES. 261 of male to female births is the same as from monogamous unions. Hardly any animal has been rendered so highly po- lygamous 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 vari ous animals; and will then briefly discuss how far selection has come into play in determining the result. .Lorses.—Mr. ‘Tegetmeier has been so kind as to tabulate for me from the ‘‘ Racing Calendar ”’ the births of race-horses dur- ing a period of twenty-one years, viz., from 1846 to 1867; 1849 being omitted, as no returns were that year published. The total births were 25,560, consisting of 12,763 males and 12,797 females, or in the proportion of 99.7 males to 100 females. As these numbers are tolerably large, and as they are drawn from all parts of England, during several years, we may with much confidence conclude that with the domestic horse, or at least with the race-horse, the two sexes are produced in almost equal numbers. ‘The fluctuations in the proportions during successive years are closely like those which occur with mankind, when a small and 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 guccessive years ; and the females exceeded the males during two periods each of four years: this, however, may be acci- dental; at least I can detect nothing of the kind with man in the decennial table in the Registrar’s Report for 1866. Dogs.—During a period of twelve years, from 1857 to 1868, the births of a large number of greyhounds, throughout England, were sent to the /ze/d newspaper ; and I am again indebted to Mr. Tegetmeier for carefully tabulating the results. The recorded births were 6,878, consisting of 3,605 males and 3,273 females, that is, inthe proportion of t10.1 males to 100 females. The greatest fluctuations occurred in 1864, when the proportion was as 95.3 males, and in 1867, as 116.3 males to 100 females. ‘The above average proportion of 110.1 to 100 is probably nearly correct in the case of the greyhound, but whether it would hold with other domesticated breeds is in $8 During eleven years a record was kept from one-third of the mares failed to produce of the nunfber of mares which proved barren living foals. Thus during 1866, 809 male or prematurely .tipped their foals; and it colts and 816 female colts were born, and deserves notice, as showing how infertile 743 mares failed S produce offspring. Dur- these highly nurtured and rather closely-. ing 1867, 836 males and goz Elen war interbied animals have become, that not far born, and 794 mares failed. —- aoe ae ‘262 THE DESCENT OF MAN. [PART 11. some degree doubtful. Mr. Cupples has inquired from several great breeders of dogs, and finds that all, without exception, be- lieve 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 im- pression on the mind. Sheep.—The sexes of sheep are not ascertained by agricult- urists until several months after birth, at the period when the males are castrated ; so that the following returns do not give the proportions at birth. Moreover, I find that several great breeders in Scotland, who annually raise some thousand sheep, are firmly convinced that a larger proportion of males than of females die during the first year or two. ‘Therefore the pro- portion of males would be somewhat larger at birth than at the age of Castration. This isa remarkable coincidence with what, as we have seen, occurs with mankind, and both cases proba- bly depend on the same cause. I have received returns from four gentlemen in England who have bred Lowland sheep, chiefly Leicesters, during the last ten to sixteen years; they amount altogether to 8,965 births, consisting of 4,407 males and 4,558 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 1867-69, but some of the returns extend back to 1862. The total num- ber recorded amounts to 50,685, consisting of 25,071 males and 25,614 females, or in the proportion of 97.9 males to 100 females. If we take the English and Scotch returns together, the total number amounts to 59,650, consisting of 29,478 males and 30,172 females, or as 97.7 to 100. So that with sheep at the age of castration the females are certainly in excess of the males, but probably this would not hold good at birth.® 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-calves; 7.e., in the proportion of 94.4 males to 100 females. The Rev. W. D. Fox informs me that in 1867, out of 34 calves born on a farm in Derbyshire, only one was a bull. Mr. Harrison Weir has inquired from severai breeders of Pigs, and most of them estimate the male to the 59 T am much indebted to Mr. Cupples for premature deaths of the males—a statemen? having procured for me the above returns subsequently confirmed by Mr. Aitchison €rom Scotland, as well as some of the follow- and others. To this latter gentleman, and ing returns on cattle. Mr. R. Elliot, of to Mr. Payan, I owe my for |; wood, first called my attention to the returns as to sheep cHaP. vil.] PROPORTION OF THE SEXES. 2063 female births as about 7 to 6. ‘This same gentleman has bred Rabbits for many years, and has noticed that a far greater num- ber 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 con- flicting statements. Mr. R. 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 himself subsequently examined some hundred old ones, and found the statement true. Mr. F. Buckland has bred a large number of white rats, and he also believes that the males greatly exceed the females. In regard to Moles, it is said that ‘‘the males are much more numerous than the females; ’’ ® 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 South Africa (Kobus ellipsiprymnus), remarks that, in the herds of this and other spe- cies, the males are few in number compared with the females: the natives believe that they are born in this proportion ; others believe that the younger males are expelled from the herds, and Sir A. Smith says that, though he has himself never seen herds consisting of young males alone, others affirm that this does occur. It appears probable that the young, when expelled from the herd, would often fall a prey to the many beasts of prey of the country. Birds.—With respect to the Fow/, I have received only one account, namely, that out of 1,001 chickens of a highly bred stock of Cochins, reared during eight years by Mr. Stretch, 487 proved males, and 514 females; 7.¢., 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- meéier informs me, can always be purchased cheaper than females. Usually the two birds reared from the two eggs laid in the same nest are a male and a female, but Mr. Harrison Weir, who has been so large a breeder, says that he has often bred two cocks from the same nest, and seldom two hens; moreover, the hen is generally the weaker of the two, and more liable to perish. With respect to birds in astate of nature, Mr. Gould and 6° Bell, “ History of British Quadrupeds,” 61 ‘‘[llustrations of the Zoology ef S, P. 100, Africa,” 1849, pl. 29. 2 264. THE DESCENT OF MAN, [PART 11 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 wild birds, and he in- forms Mr. Jenner Weir that four or five males to one female are generally produced. An experienced observer remarks ™ that in Scandinavia the broods of the capercailzie and blackcock contain more males than females; and that with the Dal-ripa (a kind of ptarmigan) more males than females attend the /eks or places of courtship ; but this latter circumstance is accounted for by some observers by a greater number of hen birds being killed by vermin. From various facts given by White, of Selborne,™ it seems clear that the males of the partridge must be in considerable excess in the south of England; and I have been assured that this is the case in Scotland. Mr. Weir, on inquiring from the dealers, who receive at certain seasons large numbers of ruffs (Alachetes pugnax), was told that the males are much the more numerous. ‘This same naturalist has also inquired for me from the bird-catchers, who annually catch an astonishing number of various small species alive for the London market, and he was unhesitatingly answered by an old and trustworthy man, that with the chaffinch the males are in large excess; he thought as high as 2 males to 1 female, or at least as high as 5 to 3.® ‘The males of the blackbird, he like- wise 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 (Lizaria mon- tana), 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, how- ever, be borne in mind that the chief season for catching birds does not begin till September, so that with some species par- tial migrations may have begun, and the flocks at this period often consist of hens alone. Mr. Salvin paid particular at- “2 Brehm (‘ Illust. Thierleben,” B. iv. s. following year. To show the number of 990) comes to the same conclusion. living chaffinches caught, 1 may mention 68 On the authority of L. Lloyd, “‘Game_ that in 1869 there was a match between two Birds of Sweden,” 1867, pp. 12, 132. experts, and one man caught ina day 62, 64 «* Nat. Hist. of Selborne,” letter xxix. and another 40, male chaffinches. The edit. of 1825, vol. i. p. 139. greatest number ever caught by one man 13 6* Mr. Jenner Weir received similar in- a single day was 70. ih formation, on making inquiries during the se Ce ~ a9 CHAP. VII.) PROPORTION OF THE SEXES. 265 tention 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 sea- sons 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 bear- ing on this latter point, I may add, that Mr. Powys found in Corfu and Epirus the sexes of the chaffinch keeping apart, and ‘«the females by far the most numerous;’’ while in Palestine Mr. Tristram found ‘‘ the male flocks appearing greatly to ex- ceed the female in number.’’* So again with the Quzscalus major, Mr. G. Taylor -says that in Florida there were ‘< very few females in proportion to the males,’’ while in Honduras the proportion was the other way, the species there having the character of a polygamist. fish.—With Fish the proportional numbers of the sexes can be ascertained only by catching them in the adult or nearly adult state; and there are many difficulties in arriving at any just conclusion.” Infertile females might readily be mistaken for males, as Dr. Giinther has remarked to me in regard to trout. With some species the males are believed to die soon after fertilizing the ova. With many species the males are of much smaller size than the females, so that a large number of males would escape from the same net by which the females were caught. M. Carbonnier “” who has especially attended to the natural history of the pike (sox /uctus), 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 propor- tional numbers have been actually observed, the males ap- pear to be largely in excess. Thus Mr. R. Buist, the superin- tendent of the Stormontfield experiments; says that in 1865, out of 7o salmon first landed for the purpose of obtaining the ova, upward of 60 were males. In 1867 he again ‘‘ calls attention to the vast disproportion of the males to the females. We had 46 ** Ibis,” vol, ii. p. 260, as quoted in 69 Leuckart quotes Pia (Wagner, Gould’s ‘* Trochilidz,” 1861, p- 52. For ‘‘Handwéorterbuch der Phys,” B. iv. 1853, the foregoing proportions I am indebted to s. 775), that with fish there are twice as Mr, tee for a table of his results. many males as females. ‘* Ibis,’ 1860, p. 137; and 1867, p. 369. 70 Quoted in the ‘‘ Farmer,” March 18, es Ibis,” 1862, DP. 137- ; 1869, Pp. 369. (L)—Vol. 3 20356 THE DESCENT OF MAN, (PART 11. at the outset at least ten males to one female.’’. Afterward 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 zzvariably hap- pens 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 cap- tive. 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 care- fully 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 Lord Portsmouth’s park, 150 were males, and 62 females. The males of the Cyprinidz likewise seem to be in excess ; but several members of this Family, viz., the carp, tench, bream, and minnow, appear regularly to follow the practice, rare in she animal kingdom, of polyandry; for the female while spawning is always attended by two males, one on each side, and in the case of the bream, by three or four males. This fact is so well known, that it is always recommended to stock a pond with two male tenches to one female, or at least with three males to two females. With the minnow, an excellent observer states that on the spawning-beds the males are ten times as numerous as the females; when a female comes among the males, ‘‘she is immediately pressed closely by a male on each side ; and when they have been in that situation for a time, are superseded by other two males.’’ ® Insects.—In this great Class the Lepidoptera almost alone afford means for judging of the proportional numbers of the © sexes ; for they have been collected with special care by many good observers, and have been largely bred from the egg or caterpillar state. I had hoped that some breeders of silk-moths might have kept an exact record, but after writing to France and Italy, and consulting various treatises, I cannot find that 71 The Stormontfield Piscicultural Ex- 1826, p. 307; on the Cyprinus carpio, p. periments,” 1866, p. 23. The “Field” 331; on the Tinca vulgarts, p. 331; on the newspaper, June 29, 1867. Abramis brama, p. 336. See, for the 72 “Land and Water, j 1868, p minnow (Leuciscus phoxinus), ‘* Loudon’ 73 Yarrell, “‘ Hist. British F ishes,”” vol. i. Mag. of Nat. Hist.” vol. v. 1832, p- 682. a. ~- CHAP, VIII.) PROPORTION OF THE SEXES. 207 this has ever been done. The general opinion appears to be that the sexes are nearly equal; but in Italy, as I hear from Prof. Canestrini, many breeders are convinced that the females are produced in excess. ‘This same naturalist, how- ever, informs me that in the two yearly broods of the Ailan- thus silk-moth (Bombyx cynthia), the males greatly prepon- derate in the first, while 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 preponder- ance 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 proportion of a hundred to one. In North America, Edwards, who had great experience, estimates in the genus Papilio the males to the females as four to one ; and Mr. Walsh, who informed me of this statement, says that with P. ¢urnus this is certainly the case. In South Africa, Mr. R. Trimen found the males in excess in 19g 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 perhaps offer an exception. Mr. Wallace® states that the females of Ornithoptera cresus, in the Malay archipelago, are more com- mon and more easily caught than the males; but this is a rare butterfly. JI may here add, that in Hyperythra, a genus of moths, Guenée says that from four to five females are sent in collections from India for one male. When this subject of the proportional numbers of the sexes of insects was brought before the Entomological Society,” it was generally admitted that the males of most Lepidoptera, in the adult or imago state, are caught in greater numbers than 74 Leuckart quotes Meinecke (Wagner, Trimen in his ‘‘Rhopalocera Africe Aus “Handworterbuch der Phys.” B. iv. 1853, tralis.” &. 775) that the males of Butterflies are three 77 Quoted by Trimen, “Transact. Ent. or four times as numerous as the females. Soc.” vol. v. part iv. 1866, p. 330. _ 78 “*The Naturalist on the Amazons,” vol. 78 **'Transact. Linn. Soc.” vol. xxv. P- 3% Ki. 1863, pp. 228, 347. 79 Proc. Mntomolog. Soc.” Feb, xy, , 7 Four of these cases are given by Mr. 1868 : ; 268 THE DESCENT OF MAN. (PART 7m. the females ; but this fact was attributed by various observers to the more retiring habits of ‘the females, and to the males emerging earlier from the cocoon. ‘This latter circumstance is well known to occur with most Lepidoptera, as well as with other insects. So that, as M. Personnat remarks, the males of the domesticated Bombyx Yamamai are useless at the begin- ning 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 butterflies which are extremely common in their native countries. Mr. Stainton, who has paid very close atten- tion during many years to the smaller moths, informs me that when he collected them in the imago state, he thought that the males were ten times as numerous as the females, but that, since he has reared them on a large scale from the caterpillar state, he is convinced that the females are the more numerous. Several entomologists concur in this view. Mr. Doubleday, however, and some others take an opposite view, and are convinced that they have reared from the eggs and caterpillars a larger proportion of males than of females. Besides the more active habits of the males, their earlier emergence from the cocoon, and in some places their frequenting more open stations, other causes may be assigned for an appar- ent or real difference in the proportional numbers of the sexes of Lepidoptera, when captured in the imago state, and when reared from the egg or caterpillar state. I hear from Prof. Canestrini, that it is believed by many breeders in Italy that the female caterpillar of the silk-moth suffers more from the recent disease than the male, and Dr. Staudinger informs me that in rearing Lepidoptera more females die in the cocoon | than males. With many species the female caterpillar is larger than the male, and a collector would naturally choose the finest specimens, and thus unintentionally collect a larger number of females. Three collectors have told me that this was their practice ; but Dr. Wallace is sure that most collectors take all the specimens which they can find of the rarer kinds, which alone are worth the trouble of rearing. Birds when surrounded by caterpillars would probably devour the largest ; and Prof. Canestrini informs me that in Italy some breeders believe, though on insufficient evidence, that in the first broods of the Ailanthus silk-moth the wasps destroy a larger number of the female than of the male caterpillars. Dr. Wallace further ®0 Quoted by Dr. Wallace in * Proc. Ent, Soc,” 3d series, vol. v. 1867, p. 487. CHAP, VIII.) PROPORTION OF THE SEXES. 26g remarks that female caterpillars, from being larger than the meles, require more time for their development, and consume more food and moisture; and thus they would be exposed during a longer time to danger from ichneumons, birds, etc., and in times of scarcity would perish in greater numbers. Hence it appears quite possible that, in a’state of nature, fewer female Lepidoptera may reach maturity than males; and for our special object we are concerned with their 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 Elachista rufocinerea. It is well known that if a virgin Lasio- campa 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 endeavored to gain admittance. In Australia, M. Verreaux, having placed the fe- male 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 of well-marked varieties of butter- flies (Rhopalocera). The prices for both sexes of the very common species are of course the same; but in 114 of the rarer species they differ ; the males being in all cases, excepting one, the cheaper. On an average of the prices of the 113 species, the price of the male to that of the female is as too to 149 ; and this apparently indicates that inversely the males ex- ceed the females in the same proportion. About 2,000 species or varieties of moths: (Heterocera) are catalogued, those with wingless females being here excluded on account of the differ- ence in habits between the two sexes: of these 2,000 species, 8! Blanchard, ‘‘Métamorphoses, Moeurs — ®2_ ‘‘ Lepidopteren~ Doubletten Liste,” des ” 1868, pp. 225-226, : Berlin, Nox. ~~ Me . 4 270 THE DESCENT OF MAN. {PART 1% 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 Eng- land has had more experience) that there is nothing in the habits of the species which can account for the difference in the prices of the two sexes, and that it can be accounted for only by an excess in the number of the males. But I am bound to add that Dr. Staudinger informs me that he is himself of a different opinion. He thinks that the less active habits of the females and the earlier emergence of the males will account for his collectors securing a larger number of males than of females, and consequently for the lower prices of the former. With respect to specimens reared from the caterpillar state, Dr. Staudinger believes, as previously stated, that a greater number of females than of males die while confined in the cocoons. He 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 from eggs or caterpillars, I have received only the few following cases : Males. Females. The Rev. J. Hellins, ** of Exeter, reared, que 1868, imagos of 73 species, which consisted of | Mr. Albert Jones, of Eltham, reared, during 1868, imagos of g species, which consisted of | During 1869 he reared imagos from 4 species, Phd sisting of . Mr. Buckler, of Emsworth, Hants, during 1869, }| 180 169 reared imagos from 74 species, consisting of . 5 Dr. Wallace, of Colchester, reared from one brood of ) Bombyx cynthia . i Dr. Wallace raised, from cocoons of “Bombyx “Pernyi ) sent from China, during 1869 . | Dr. Wallace raised, during 1868 and 1869, from two “ns lots of cocoons of Bombyx yama-mai . . Total e e e e e e e e e o e e e 934 76% So that in these eight lots of cocoons and eggs, males were produced in excess. ‘Taken together, the proportion of males 88 This naturalist has been so kind as to but so many of the figures were estimates, send me some results from former years, in that I found it impossible to tabulate them, which the females seemed to preponderate; 7 CHAP. VII} PROPORTION OF THE SEXES, 27? is as 122.7 to 100 females. But the numbers are hardly large enough to be trustworthy. On the whole, from these various sources of evidence, all pointing in the same direction, I infer that with most species of Lepidoptera, the mature males generally exceed the females in number, whatever the proportions may be at their first emer- gence 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 (Zucanus cervus) ‘‘ the males appear to be much more numerous than the females;’’ but when, as Cornelius re- marked during 1867, an unusual number of these beetles ap- peared in one part of Germany, the females appeared to exceed the males as six to one. With one of the Elateridz, 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 polyandry seems to prevail.’’ With Siagonium (Staphylinidze), 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 fe- males of the bark-feeding Zomzcus villosus are so common as to be a plague, while the males are so rare as to be hardly known. It is hardly worth while saying anything about the propor- tion 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; exam- ples of this are afforded by several of the Cynipide.® In all the gall-making Cynipidze known to Mr. Walsh, the females are four or five times as numerous as the males; and so it is, as he informs me, with the gall-making Cecidomyiiz (Dip- tera). With some common species of Saw-flies (Tenthredinz) Mr. F. Smith has reared hundreds of specimens from larve 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 ; while 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 84 Giinther’s “‘ Record of Zoological Lit- 85 Walsh, in “The American Entomolo- erature,” 1867, p. 260. On the excess of gist,” vol. i. 1869, p. 103. F. Smith, ‘‘ Rec- female Lucanus, ibid. p. 250. Onthe males ord of Zoological Literature,” 1867, p. 328. of Lucanus in England, Westwood, *‘ Mod- 86 ** Farm Insects,” pp. 45-46. ern Class. of Insects,” vol. i, p. 187. On the 87 ** Anwendung der Darwin’schen Lehre,” Siagonium, ibid. p. 172. “Verh, d. n. V. Jahrg.”’ xxiy. 272 THE DESCENT OF MAN, [PART It, 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 ex- cess. Miiller 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 Miiller, has noticed in Brazil that the two sexes of the same species of bee sometimes frequent different kinds of flowers. With respect to the Orthoptera, I know hardly anything about the relative number of the sexes ; Korte,** however, says that, out of 500 locusts which he examined, the males were to the females as five to six. With the Neuroptera, Mr. Walsh states that in many, but by no means in all the species of the Odona- tous group, there is a great overplus of males; in the genus Heteerina, 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, while in two other species the females are twice or thrice as numerous as the males. In some European species of Psocus thousands of fe- males may be collected without a single male, while with other species of the same genus both sexes are common.® In Eng- land, Mr. MacLachlan has captured hundreds of the female Apatania mulicbris, but has never seen the male; and of Boreus hyemalis only four or five males have been seen here.” With most of these species (excepting the Tenthredinz) there is at present no evidence that the females are subject to par- thenogenesis ; 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 less information. With Spiders, Mr. Blackwall, who has carefully attended to this class during many years, writes to me that the males, from their more erratic habits, are more commonly seen, and therefore appear more numerous. This is actually the case with a few species ; but he mentions 88“ Die Strich-, Zug- oder Wanderheu- “Proc. Ent. aa Philadelphia,” Oct. 1863, schrecke, »” 1828, p. 20. pp. 168, 223, 2 ‘Observations on N. American Neu- 9° * Proc. Ent Soc. London,” Feb. 13 capeien? by H. Hagen and B. D, Walsh, 1868. cuAp. vit.) PROPORTION OF THE SEXES. _ 273 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 sometimes carried to an extreme degree), and their widely dif- ferent appearance, may account in some instances for their rarity in collections.” Some of the lower Crustaceans are able to propagate their kind asexually, and this will 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 among 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 shorter lived than the females ; and this would explain their scarcity, supposing the two sexes to be at first equal in number. On the other hand, Miiller has invariably taken far more males than females of the Diastylidz 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 pre- ponderance may be due to some unknown difference in the habits of the two sexes. With one of the higher Brazilian crabs, namely, a Gelasimus, Fritz Miiller found the males to be more numerous than the females. According to the large ex- perience of Mr. C. Spence Bate, the reverse seems to be the case with six common British crabs, the names of which he has given me. Lhe Proportion of the Sexes tn 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 Mr. Wright, of Yeldersley House, informs me that one of his Arab mares, though put seven times to different horses, produced seven fillies. Though I have very little evidence on this head, analogy would lead to the belief that the tendency to produce either sex would be inherited like almost every other peculiar- $1 Another great authority with respect to 2 See, on this subject, Mr. O. P. Cam- this class, Prof. Thorell of Upsala (*‘On_ bridge, as quoted in “‘ Quarterly Journal of European Spiders,” 1869-70, parti. p. 205) Science,” 1868, p. 429. speaks as if female spiders were generally °° “‘ Beitrage zur Parthenogenesis,” $e eemmoner than the males, 174 274 THE DESCENT OF MAN [PART IL ity, for instance, that of producing twins ; and concerning the above tendency a good authority, Mr. J. Downing, has com- municated 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, consist of 112 males and 84 females of all ages—that is in a ratio of 133.3 malesto roo females, ‘The Todas, who are polyandrous in their marriages, during former times invariably practised female infanticide ; but this practice has now been discontinued for a considerable period. Of the children born within late years, the males are more numerous than the females, in the proportion of 124 to 100. Col. Marshall accounts for this fact in the following ingenious man- ner: ‘‘ Let us for che purpose of illustration take three families as representing an average of the entire tribe; say that one mother gives birth to six daughters and no sons; a second mother has six sons only, while the third mother has three sons and three daughters. The first mother, following the tri- bal custom, destroys four daughters and preserves two. ‘The second retains her six sons. The third kills two daughters and keeps one, as also her three sons. We have, then, from the three families, nine sons and three daughters, with which to continue the breed. But while 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 form of infanti- cide seems almost certain ; that is if we assume that a sex-pro- ducing tendency is inherited. But as the above numbers are so extremely scanty, I have searched for additional evidence, but cannot decide whether what I have found is trustworthy ; nevertheless the facts are, perhaps, worth giving. The Maories of New Zealand have long practised infanticide; and Mr. Fenton® states that he ‘‘ has met with instances of women who have destroyed four, six, and even seven chiidren, mostly females. However, the universal testimony of those best quali- fied 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 among the New Zealanders, as with the Todas, male births are considerably in 9 “ The Todas,” 1873, pp. 100, III, 194, % ** Aboriginal Inhabitants of New Zea 396, : land ; Government Report,” 1899; D- 36. CHAP. Vils.} PROPORTION OF THE SEXES, 275 excess. Mr. Fenton remarks (p. 30): ‘‘ One fact is certain, although the exact period of the commencement of this singu- lar condition of the disproportion of the sexes cannot be de- monstratively fixed, it is quite clear that this course of decrease was in full operation 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 are not large, and as the census was not accu- rate, 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 civil- ized 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 fe- males of all ages, that is in the ratio of 130.3 males to 100 females. But during this same year, and in certain limited dis- tricts, the numbers were ascertained with much care, and the males of all ages were here 753 and the females 616; that is in the ratio of 122.2 males to 100 females. It is more important for us that during this same year of 1858 the xon-adu/t males within the same district were found to be 178, and the zon- 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 ~on-adu/¢t males in one district were 25r, and the zon-adult 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 fright- ful extent, but was by no means confined to female infants, as is shown by Mr. Ellis,® and as I have been informed by Bishop Staley and the Rev. Mr. Coan. Nevertheless, another appar- ently trustworthy writer, Mr. Jarves,” whose observations ap- ply to the whole archipelago, remarks: ‘‘ Numbers of women are to be found who confess to the murder of from three to six or eight children ;’’ and he adds, ‘‘ females, from eiag considered less useful than males, were more often destroyed.’’ From what is known to occur in other parts of the world, this statement is probable, but must be received with much cau- tion. The practice of infanticide ceased about the year 1819, 96 ** Narrative of a Tour through Hawaii,” °7 ‘‘ History ef the Sandwicb isiards,® 2826, p. 298. 1843, P> 9% . 276 THE DESCENT OF MAN. (PART rt. 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 4,723 males and 3,776 females ; that is in the ratio of 125.08 to 100. At the same time the number of males under fourteen years in Kauai, and under eighteen in Oahu was 1,797, and of females of the same ages 1,429; and here we have the ratio of 125.75 males to 100 females. In a census of all the islands in 1850, the males of all ages amount to 36,272, and the females to 33,128, or as 109.49 to 1oo. ‘The males under seventeen years amounted to 10,773, and the females under the same age to 9,593, or as 112.3 to too. 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 fe. males, and not of the births; and, judging from all civilized countries, the proportion of males would have been consider- ably higher if the numbers had referred to births.” From the several foregoing cases we have some reason to be- lieve that infanticide practised in the manner above explained tends 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. 98 This is given in the Rev. H.'T. Chee- ver’s “* Life in the Sandwich Islands,” 1851, . 277. Poe Dr. Coulter, in describing (‘' Journal R. Geograph. Soc.” vol. v. 1835, p. 67), the state of California about the year 1830, says that the natives, reclaimed by the Spanish missionaries, have nearly all perished, or are perishing, although well treated, not driven from their native land, and kept from the use of spirits. He attributes this, in great part, to the undoubted fact that the men greatly exceed the wo.:nen in number; but he does not know whether this is due to a failure of female offspring, or to more fe- males dying during early youth. The latter alternative, according to all analogy, is very improbable. He adds that ‘infanticide, properly so called, is not common, though very frequent recourse. is had to abortion.” If Dr. Coulter is correct about infanticide, this case cannot be advanced in support of Col. Marshall’s view. From the rapid de- crease of the reclaimed natives, we may sus- ct that, as in the cases lately given, their Fertility has been diminished from changed habits of life. There may be some unknown law lead- I had hoped to gain some light on this subject from the breeding of dogs; inas- much 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 noth- ing of 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 inguiries made from many . breeders, it seems that the females are in some respects more esteemed, though other- wise troublesome ; and it does not appear that the female puppies of the best-bred dogs are systematically destroyed more than the males, though this does sometimes take place to a limited extent. Therefore I am unable to decide whether we can, on the above principles, account for the preponder- ance of male births’in greyhounds. On the other hand, we have seen that with horses, cattle, and sheep, which are too valuabie for the young of either sex to be destroyed, if there is any difference, the are slightly in excess. cuap. vi.) PROPORTION OF THE SEXES. 277 ing to this result in decreasing races which have already be- come somewhat infertile. Besides the several causes previously alluded to, the greater facility of parturition among 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 Tahi- tians now inhabiting Norfolk Isiand. 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 asI 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 comparison with the males, and to whom this preponderance is of paramount importance, we can see that those communities would flourish best which contained females having a strong inherited tendency to produce more and more females; and in guch cases an unequal sex-producing tendency would be ulti- mately gained through natural selection. With animals living in herds or troops, in which the males come to the front and defend the herd, as with the bisons of North America and cer- tain 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 mcre numerous descend- ants. In the case of mankind the advantage arising from having a preponderance of men in the tmbe 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 ine dividuals 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 couid not be gained through natural selection. Nevertheless, there are certain animals (for instance, fishes and cirripedes) in which two or more males appear to be necessary for the fertilization 9f the female; and the males accordingly largely preponderate, 278 THE DESCENT OF MAN. {PART ft, out it is by no means obvious how this male-producing ten- dency could have been acquired. I formerly thought that when a tendency to produce the two sexes in equal numbers was advantageous to the species, it would follow from natural selection, but I now see that the whole problem is so intricate that it is safer to leave its solution for the future. CHAPTER IX. SECONDARY SEXUAL CHARACTERS IN THE LOWER CLASSES OF THE ANIMAL KINGDOM. These characters absent in the lowest classes—Brilliant colors—Mollusca —Annelids—Crustacea, secondary sexual characters strongly devel- oped ; dimorphism ; color; characters not acquired before maturity —Spiders, sexual colors of ; stridulation by the males—Myriapoda, WiTH animals belonging to the lower classes, the two sexes are not rarely united in the same individual, and therefore sec- endary sexual characters cannot be developed. In many cases where the sexes are separate, both are permanently attached to some support, and the one cannot search or struggle for the other. Moreover, it is almost certain that these animals have too imperfect senses and much too low mental powers to appreciate each other’s beauty or other attractions, or to feel rivalry. Hence in these classes or subkingdoms, such as the Protozoa, Coelenterata, Echinodermata, Scolecida, secondary sexual char- acters, of the kind which we have to consider, do not occur ; and this fact agrees with the belief that such characters in the higher classes have been acquired through sexual selection, which depends on the will, desire, and choice of either sex. Nevertheless some few apparent exceptions occur; thus, as I hear from Dr. Baird, the males of certain Entozoa, or internal parasitic worms, differ slightly in color 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 hermaphroaites or with separate sexes, are ornamented with the most brilhant tints, or are shaded and striped in an elegant manner; yor instaare, CHAP, IX.) SEXUAL SELECTION. 279 many corals and sea-anemones (Actiniz), some jelly-fish (Me- dusz, Porpita, etc.), some Planariz, many star-fishes, Echini, Ascidians, etc.; but we may conclude from the reasons al- ready indicated, namely, the union of the two sexes in some of these animals, the permanently affixed condition of others, and the low mental powers of all, that such colors do not serve as a sexual attraction, and have not been acquired through sexual selection. It should be borne in mind that in no case have we sufficient evidence that colors have been thus acquired, except where one sex is much more brilliantly or conspicu- ously colored than the other, and where there is no difference in habits between the sexes sufficient to account for their dif- ferent colors. But the evidence is rendered as complete as it can ever be, only when the more ornamented individuals, almost always the males, voluntarily display their attractions before the other sex ; for we cannot believe that such display is useless, and if it be advantageous, sexual selection will al- most inevitably follow. We may, however, extend this con- clusion to both sexes, when colored alike, if their colors 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 gor- geous colors of many animals in the lowest classes? It appears doubtful whether such colors often serve as a protection; but that we may easily err on this head will be admitted by every- one who reads Mr. Wallace’s excellent essay on this subject. It would not, for instance, at first occur to any one that the transparency of the Medusz, or jelly-fishes, is of the highest service to them as a protection ; but when we are reminded by Hackel that not only the medusze, but many floating mollusca, crustaceans, and even small oceanic fishes partake of this same glass-like appearance, often accompanied by prismatic colors, 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 pro- tection. Conspicuous colors are likewise beneficial to many animals 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 nat- ure or the minute structure of their tissues, independently of any } “Archives de Zoolog. Expér.” Oct, 1872, p. 563 bg 280 THE DESCENT OF MAN. [PART ft benefit thus derived. Hardly any color is finer than that of arterial blood ; but there is no reason to suppose that the color of the blood is in itself any advantage ; and, though it adds to the beauty of the maiden’s cheek, no one will pretend that it has been acquired for this purpose. So again with many ani- mals, especially the lower ones, the bile is richly colored ; thus, as Iam informed by Mr. Hancock, the extreme beauty of the Eolidz (naked sea-slugs) is chiefly due to the biliary glands being seen through the translucent integuments—this beauty being probably of no service to these animals. The tints of the decaying leaves in an American forest are described by everyone as gorgeous ; yet no one supposes that these tints are of the least advantage to the trees. Bearing in mind how many substances closely analogous to natural organic compounds have been re- cently formed by chemists, and which exhibit the most splendid coJors, it would have been a strange fact if substances similiarly colored had not often originated, independently of any useful end thus gained, in the complex laboratory of living organisms. The Subkingdom of the Mollusca.—Throughout this great division of the animal kingdom, as far as I can discover, sec- ondary 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 (constitut- ing the Molluscoida of some authors), for most of these animals are permanently affixed to a support or have their sexes united in the same individual. In the Lamellibranchiata, or bivalve shells, hermaphroditism is not rare. In the next higher class of the Gasteropoda, or univalve shells, the sexes are either united or separate. But in the latter case the males never possess special organs for finding, securing, or charming the females, or for fighting with other males. As I am informed by Mr. Gwyn Jeffreys, the sole external difference between the sexes consists in the shell sometimes differing a little in form ; for instance, the shell of the male periwinkle (Letforina “Lit- torea) isenarrower 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 fur- nished with imperfect eyes, do not appear to be endowed with suffictent mental powers for the members of the same sex to Xruggle together in rivalry, and thus to acquire secondary sexual characters. Nevertheless, with the pulmoniferous gass "CHAP, 1X.} MOLLUSCS. 281 terspods, or land-snails, the pairing is preceded by courtship ; for these animals, though hermaphrodites, are compelled by their structure to pair together. Agassiz remarks,” ‘‘ Qui- conque a eu l’occasion d’observer les amours des limacons, ne saurait mettre en doute laséduction déployée dans les mouve- ments et les allures qui préparent et accomplissent le double emibrassement de ces hermaphrodites.’’ These animals ap. pear also susceptible of some degree of permanent attachment : am accurate observer, Mr. Lonsdale, informs me that he placed a pair of land-snails (Helix pomatia), one of which was weakly, into a small and ill-provided 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 returned, and apparently communicated the result of its suc- cessful exploration, for both then started along the same track and disappeared over the wall. Even in the highest class of the Mollusca, the Cephalopoda, er 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 surprising circumstance, as these animals possess highly developed sense-organs and have considerable mental powers, as will be admitted by everyone who has watched their artful endeavors to escape from anenemy.® Cer- tain Cephalopoda, however, are characterized by one extraor- dinary 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 under the name of Hectocotyle. But this marvellous structure may be classed as a primary rather than as a second- ary sexual character. Although with the Mollusca sexual selection does not seem to have come into play, yet many univalve and bivalve shells, such as volutes, cones, scallops, etc., are beautifully colored and shaped. The colors 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 pat- terns and the sculpture of the shell depending on its manner of 2 “De l’Espéce et de la Class.” etc., 1869, have given in my ‘* Journal of Researches,” “ine 1845 P- 7+ See, for instance, the account which I 282 2ViHiE DESCENT OF MAN. (PART 11, growth. ‘The amount of light seems to be influential to a cer- tain extent ; for although, as repeatedly stated by Mr. Gwyn Jeffreys, the shells of some species living at a profound depth are brightly colored, yet we generally see the lower surfaces, as well as the parts covered by the mantle, less highly colored than the upper and exposed surfaces.‘ In some cases, as with shells living among corals or brightly tinted sea-weeds, the bright colors may serve as a protection.® But that many of the nudibranch mollusca, or sea-slugs, are as beautifully colored as any shells, may be seen in Messrs. Alder and Hancock’s mag- nificent work ; and, from information kindly given me by Mr. Hancock, it seems extremely doubtful whether these colors usually serve as a protection. With some species this may be the case, as with one kind which lives on the green leaves of alge, and is itself bright-green. But many brightly colored, white, or otherwise conspicuous species do not seek conceal- ment ; while again some equally conspicuous species, as well as other dull-colored kinds, live under stones and in dark recesses. So that with these nudibranch molluscs, color apparently does not stand in any close relation to the nature of the places which they inhabit. These naked sea-slugs are hermaphrodites, yet they pair together, as do land-snails, many of which have extremely pretty shells. It is conceivable that two hermaphrodites, attracted by each other’s greater beauty, might unite and leave offspring which would inherit their parents’ greater beauty. But with such lowly organized creatures this is extremely im- probable. Nor is it at all obvious how the offspring from the more beautiful pairs of hermaphrodites would have any advan- tage over the offspring of the less beautiful, so as to increase in number, unless indeed vigor 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 se- lected by the more vigorous females. If, indeed, brilliant col- ors were beneficial to an 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. Subkingdom of the Vermes: Class, Annedida (or Sea- 4 I have given (‘‘ Geolog. Observationson = ® Dr. Morse has lately discussed this sub- Volcanic Islands,” 1844, p- 53) a curious in- ject in his paper on the Adaptive Coloration stance of the influence of light on the colors of of Mollusca. *‘ Proceedings of the Boston a frondescent incrustation, deposited by the Society of Natural History,” vol. xiy., April, surf on the coast-rocks of Ascension. and 1871. fermed by the solution of triturated sea-shells. CHAP, 1X.] CRUSTACEANS. 283 worms).—In this class, although the sexes, when separate, sometimes differ from each other in characters of such impor- tance that they have been placed under distinct genera or even families, yet the differences do not seem of the kind which can be safely attributed to sexual selection. These animals are often beautifully colored, but as the sexes do not differ in this respect, we are but little concerned with them. Even the Nemertians, though so lowly organized, ‘‘ vie in beauty and variety of coloring with any other group in the invertebrate series ;’’ yet Dr. McIntosh® cannot discover that these colors are of any service. The sedentary annelids become duller- colored, according to M. Quatrefages,’ after the period of re- production ; and this I presume may be attributed to their less vigorous condition at that time. All these worm-like animals apparently stand too low in the scale for the individuals of either sex to exert any choice in selecting a partner, or for the individuals of the same sex to struggle together in rivalry. Subkingdom of the Arthropoda: Class, Crustacea.——In this great class we first meet with undoubted secondary sexual characters, often developed in a remarkable manner. Unfort- unately 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 swimming- legs, antennze, and sense-organs ; the females being destitute of these organs, with their bodies often consisting of a mere dis- torted mass. But these extraordinary differences between the two sexes are, no doubt, related to their widely different habits of life, and, consequently, do net concern us. In various crustaceans, belonging to distinct families, the anterior antenn are furnished with peculiar thread-like bodies, which are be- tieved 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, would almost certainly be able sooner or later to find the females, the increased number of the smelling-threads has prob- ably been acquired through sexual selection, by the better pro- vided males having been the more successful in finding partners and in producing offspring. Fritz Miiller has described a re- markable dimorphic species of Tanais, in which the male is represented by two distinct forms, which never graduate into 6 See his beautiful popean ee on *Brit- d’aprés Darwin,” ‘‘ Revue Scientifique,” ish Annelids,”’ part i. Feb. 1873, p. 866, M, Perrier, ** POugae de (Homme 284 THE DESCENT OF MAN. [PART IL 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 chelz, or pincers, which serve to hold the female. Fritz Miiller 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 smelling-threads, while other individuals varied in the shape and size of their chelz ; so that of the former, those which were best able to find the female, and of the latter, those which were best able to hold her, have left the greatest number of progeny to inherit their respective advantages.§ In some of the lower crustaceans, the right anterior antenna a of the male differs greatly in structure from the left, the latter resembling in its simple tapering joints the antennz of the female. In the male the modi- fied antenna is either swollen in the middle or angularly bent, or con- verted (fig. 4) into an elegant, and sometimes wonderfully complex, pre- hensile 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 (4) on the same side of the body is converted into a forceps. In another family the inferior or posterior antenne are ‘‘curiously zigzagged’’ in the males alone. In the higher crustaceans the an: terior legs are developed into chele, or pincers; and these are generally larger in the male than in the female (erepasTuskanky tos Peet oF ree —so much so that the market value of anterior antenna. of male, form- the. male edible; crabi( Gagcer,; pagurus)s ing a prehensile organ. 4. Pos terioe painof-therpticlegsiof male: according to Mr. C. Spence Bate, is. ogee Sap a ae five times as great as that of the female. In many species the chelz are &**Facts and Arguments for Darwin,” Eng. 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 Nor- wegias crustacean, the Pontoporeia afinis. *See Sir J. Lubbock in **Annals and of unequal size on the opposite Mag. of Nat. Hist.” vol. xi. 1853, pl. i. and x. ; and vol, xii. (1853) pl. vii. See also Lub- bock in ‘‘ Transact. Ent. Soc.” vol. iv. new series, 1856-1858, p. 8. With respect to the zigzagged antennz mentioned below, see Fritz Miiller, “*Facts and Arguments for Darwin,” 1869, p. 40, foot-note, ~ ses = € CHAP, IX.] CRUSTACEANS. 285 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 chelz of the male often differ in struct- ure (figs. 5, 6, and 7), the smaller one resembling that of the female. What advantage is gained by their inequality in size on the opposite sides of the body, and by the inequality being much greater in the male than in the female ; and why, when they are of equal size, both are often much larger in the male Fic. 5.—Anterior part of body of Callianassa (from Milne-Edwards), showing the un- equal and differently constructed right- and left-hand chelz of the male. N.B.—The artist by mistake has reversed the drawing, and made the left-hand chela the largest. Fic, 6,—Second leg of male Orchestia Fic. 7.—Ditto of female. Tucuratinga (from Fritz Miiller). than in the female, is not known. As I hear from Mr. Bate, the chelze are sometimes of such length and size that they can- not possibly be used for carrying food to the mouth. In the males of certain fresh-water prawns (Palazmon} the right leg is 286 THE DESCENT OF MAN, | [PART 1 actually longer than the whole body.” The great size of the one leg with its chelz may aid the male in fighting with his rivals ; but this will not account for their inequality in the female on the opposite sides of the body. In Gelasimus, ac- cording to a statement quoted by Milne-Edwards," the male and the female live in the same burrow, and this shows that they pair ; the male closes the mouth of the burrow with one of its chele, which is enormously developed ; so that here it indirectly serves as a means of defence. ‘Their main use, how- ever, is probably to seize and to secure the female, and this in some instances, as with Gammarus, is known to be the case. The male of the hermit or soldier crab (Pagurus) for weeks to- gether carries about the shell inhabited by the female.” The sexes, however, of the common shore-crab (Carcinus menas), as Mr. Bate informs me, unite directly after the female has moulted her hard shell, when she is so soft that she would be injured if seized by the strong pincers of the male ; but as she is caught and carried about by the male before moulting, she could then be seized with impunity. Fritz Miiller states that certain species of Melita are distin- guished from all other amphipods by the females having ‘‘ the coxal lamellze of the penultimate pair of feet produced into ‘hook-like 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 during the act of reproduction having left the largest number of offspring. Another Brazilian amphi- pod (Orchestia Darwinit, fig. 8) presents a case of dimorphism, like that of Tanais; for there ar2 two maie’ forms, which differ in the structure of their chelz."® As either chela would cer- tainly 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, andsome 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 _ 10 See a paper by Mr. C. Spence Bate, 11 ** Hist. Nat. des. Crust.” tom. ii, 1837. with figures, in ‘‘ Proc. Zool. Soc.” 1868, p. p . 50. : 63; and on the nomenclature of the genus, 12Mr. C. Spence Bate, Brit. Assoc., — ibid. p. 585. I am greatly indebted to Mr. ‘‘Fourth Report on the Fauna of South Spence Bate for nearly all the above state- Devon.” ments with respect to the chelz of the higher 13 Fritz Miiller, ‘*Facts and Arguments orustaceaas, for Darwin,” 1869, pp. 25-28. CHAP. LX} - CRUSTACEANS, 287 to owe his greater size to his ancestors having fought with other males during many generations. In most of the orders, especially in the highest or the Brachyura, the male is larger than the female.; the parasitic genera, however, in which the Fic. 8.—Orchestia Darwinii (from Fritz Miiller), showing the differently constructed chelze of the two male forms. sexes follow different habits of life, and most of the Ento- mostraca must be excepted. The chelze of many crustaceans are weapons well adapted for fighting. Thus when a Devil- crab (Portunus puber) was seen by a son of Mr. Bate fighting with a Carcinus menas, the latter was soon thrown on its back, 288 THE DESCENT OF MAN. {PART 11, and had every limb torn from its body. When several males of a Brazilian Gelasimus, a species furnished with immense pincers, were placed together in a glass vessel by Fritz Miiller, they mutilated and killed one another. Mr. Bate put a large male Carcinus m@nas into a pan of water, inhabited by a female which was paired with a smaller male ; ; but the latter was soon dispossessed. Mr. Bate adds, ‘‘if they fought, the victory was a bloodless one, for I saw no wounds.’’ This same naturalist separated a male sand-skipper (so common on our sea-shores), Gammarus marinus, from its female, both of whom were imprisoned in the same vessel with many indi- viduals of the same species. The female, when thus divorced, soon joined the others. After a time the male was put again into the same vessel ; and he then, after swimming about for a time, dashed into the crowd, and without any fighting at once took away his wife. This fact shows that in the Amphipoda, an order low in the scale, the males and females recognize each other, and are mutually attached. The mental powers of the Crustacea are probably higher than at first sight appears probable. Any one who tries to catch one of the shore-crabs, so common on tropical coas‘s, will perceive how wary and alert they are. ‘There is a larse crab (Birgus latro) found on coral islands which makes a thick. bed of the picked fibres of the cocoa-nut, at the bottom of a deep burrow. It feeds on the fallen fruit of this tree by tear- ing off the husk, fibre by fibre; and it always begins a. 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 prob- ably instinctive, so that they would be performed as well by a young animal as by an old one. The following case, however, can hardly be so considered: A trustworthy naturalist, Mr. Gardner," while watching a shore-crab (Gelasimus) making its burrow, threw some shells toward 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 cf a foot ; it then saw the three other shells lying near, and, evi- dently thinking that they might hkewise roll in, carried them to the spot where it had laid the first. It would, I think, be ~ 14 Travels in the Interior of Brazil,” of Researches,” p. 8 an account of the — 3846, p. 111. I have given, in my « Journal habits of the Birgus. na ae tenes CMAP. 1X.] CRUSTACEANS. 289 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 color in the two sexes of our British crustaceans, in which respect the sexes of the higher animals so often differ. In some cases, however, the males and females differ slightly in tint, but Mr. Bate thinks not more than may be accounted for by their different habits of life, such as by the male wandering more about, and being thus more exposed to the light. Dr. Power tried to distinguish by color the sexes of the several species which inhabit the Mauritius, but failed, except with one species of Squilla, probably \S. styifera, the male of which is described as being ‘‘ of a beautiful bluish green,’’ with some of the appendages cherry-red, while the female is clouded with brown and gray, ‘‘ 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 belieye that even the lowest crustaceans can distinguish colors. With Saphirina (an oceanic genus of Entomostraca), the males are furnished wich minute shields or cell-like bodies, which exhibit beautiful changing colors ; 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. Iam informed by Fritz Miiller that ‘n the female of a Brazilian species of Gelasimus the whole body is of a nearly uniform grayish-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 colors are liable to change in the course of a few minutes—the white becoming dirty gray or even black, the green ‘‘ losing much of its brilliancy.’’ It de- serves especial notice that the males do not acquire their bright . colors until they become mature. They appear to be much more numerous than the females; they differ also in the larger size of their chelz. 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. F'rom these various con- siderations it seems probable that the male in this species has be- come gayly ornamented in order to attract or excite the female. 18 Mr. Ch. Fraser, in ‘ Proc, Zoolog, 16 Claus, *t Die freilebenden Co den,* Soc.” 1869, p. 3. I am indebted to Mr. Bate 1863, s. 35 pres for Dr. Power’s statement. 290 THE DESCENT OF MAN. [PART It. It has just been stated that the male Gelasiraus does not ac- quire his conspicuous colors until mature and nearly ready to breed. This seems a general rule in the whole class in respect to the many remarkable structural differences between the sexes. We shall hereafter find the same law prevailing throughout the great subkingdom of the Vertebrata ; and in all cases it is em- inently distinctive of characters which have been acquired through sexual selection. Fritz Miiller™ gives some striking instances of this law; thus the male sand-hopper (Orchestia) does not, until nearly full grown, acquire his large claspers, which are very differently constructed from those of the female ; while young, his claspers resemble those of the female. Class, Arachnida (Spiders).—The sexes do not generally differ much in color, but the males are often darker than the females, as may be seen in Mr. Blackwall’s magnificent work.® In some species, however, the difference is conspicuous ; thus the female of Sparassus smaragdulus is dullish green, while the adult male has the abdomen of a fine yellow, with three longi- tudinal 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 be- long; but Mr. Blackwall thinks that, as a general rule, it is the male; and Canestrini remarks that in certain genera the males can be specifically distinguished with ease, but the females with great difficulty. I am informed by Mr. Blackwall that the sexes while young usually resemble each other ; and both often undergo great changes in color during their succes- sive moults, before arriving at maturity. In other cases the male alone appears to change color. Thus the male of the above bright-colored Sparassus at first resembles the female, and acquires his peculiar tints only when nearly adult. Spiders are possessed of acute senses, and exhibit much intelligence ; — as is well known, the females often show the strongest affec- tion 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 »ossession of them. This same author says that the unior of the two 27 «Facts and Arguments,” etc., p. valuable essay on the “‘ Caratteri sessuali 18 “ A History of the Spiders of Great secondarii degli Arachnidi,” in the “Atti Britain,” 1861-64. For the following facts, della Soc. Veneto Trentina di Sc. Nat. Pa- see pp. 77, 88, 102. dova,” vol. i, Fasc. 3, 1873. 19 This author has recently published a : CHAP. Ix.]} SPIDERS, 291 sexes has been observed in about twenty species; and he as- serts 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 color 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 maie of his ornaments. From the extreme variability of color in the male of some species, for instance of Zheridion lineatum, it would appear that these sexual characters of the males have not as yet become well fixed. Canestrini draws the same con- clusion from the fact that the males of certain species present two forms, differing from each other in the size and length of their jaws ; and this reminds us of the above cases of dimorphic crustaceans. The male is generally much smaller than the female, some- times to an extraordinary degree,” and he is forced to be ex- tremely cautious in making his advances, as the female often carries her coyness to a dangerous pitch. De Geer saw a male that ‘‘in the midst of his preparatory caresses was seized by the object of his attentions, enveloped by her in a web, and then devoured, a sight which, as he adds, filled him with _hor- ror and indignation.’’*! The Rev. O: P. Cambridge™ ac- counts in the following manner for the extreme smallness of the male in the genus Nephila: ‘‘ M. Vinson gives a graphic account of the agile way in which the diminutive male escapes from the ferocity of the female, by gliding about and playing hide and seek over her body and along her gigantic limbs: in such a pursuit it is evident that the chances of escape would be in favor 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, é.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.’’ 20 Aug. Vinson (‘‘ Arandides des Iles de between the sexes have been recorded la Réunion,” pl. vi. figs. 1 and 2) givesa (‘* Quarterly Journal of Science,” 1868, July, good instance of the small size of the male pp. 429); but I have not seen the original ac- in Hpetra nigra. Inthis species,as I may counts. add, the male is testaceous and the female 3! Kirby and Spence, * Introduction to black, with legs banded with red. Other Entomology,” vol. i. 1818, p. 280. even more striking cases of ineauality in size 22 ‘* Proc. Zoolog. Soc.” 1871, p. 62%. ~ 292 THE DESCENT OF MAN. [PART IL Westring has made the interesting discovery that the males of several species of Theridion* have the power of making a — stridulating sound, while the females are mute. . The apparatus consists of a serrated ridge at the base of the abdomen, against which the hard hinder part of the thorax is rubbed ; and of this structure not a trace can be detected in the females. It deserves notice that several writers, including the well-known arachnologist, Walckenaer, have declared that spiders are at- tracted by music.** From the analogy of the Orthoptera and Homoptera, to be described in the next chapter, we may feel almost sure that the stridulation serves, as Westring also be- lieves, 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, Mystapoda.—In neither of the two orders in this class, the millipedes and centipedes, can I find any well-marked in- stances of such sexual differences as more particularly concera us. In Glomeris limbata, however, and perhaps in some few other species, the males differ slightly in color from the fe- males; but this Glomeris is a highly variable species, In the males of the Diplopoda, the legs belonging either to one of the anterior or of the posterior segments of the body are modified into prehensile hooks which serve to secure the female. In some species of Iulus the tarsi of the male are furnished with membranous suckers for the same purpose. As we shall see when we treat of Insects, it is a much more unusual circum- stance that it is the female in Lithobius which is furnished with prehensile appendages at the extremity of her body for holding the male.” 23 Theridion (Asagena, Sund.) serra- 25 Hilgendorf, however, has lately called tipes, 4-punctatum et guttatum; see attention to an analogous structure in some Westring, in Kroyer, ‘‘ Naturhist. Tids- of the higher crustaceans, which seems / iat krift,” vol. iv. 1842-43, p- 349; and vol, ii. 1846-49, p- 342. See also, for other species, ** Aranez Suecice,” p. 184. 24 Dr. H. H. van Zouteveen, in his Dutch translation of this work (vol. i. p. 444), has collected several cases. adapted to produce sound; see ‘* Zoological Record,” 1869, p. 603. 26 Walckenaer et P. Gervais “ Hist. Nat. des Insectes: AptereS,” tom, iv. 1847, Ppp- 17, 19, 68. baal ile SHAP, X.] 4NSECTS, 293 CHAPTER X. SECONDARY SEXUAL CHARACTERS OF INSECTS. Diversified structures possessed by the males for seizing the females— Differences between the sexes, of which the meaning is not understood —Difference in size between the sexes—Thysanura—Diptera—Hemip- tera—Homoptera, musical powers possessed hy the males alone—Or- thoptera, musical instruments of the males, much diversified in struct- ure 5 pugnacity ; colors—Neuroptera, sexual differences in color— Hymenoptera, pugnacity and colors—Coleoptera, colors ; 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 the pectinated and beautifully plumose antennze of the males In Chloéon, one of the Ephemerz, the male many species. in of has great pillared eyes, of which the female is entirely desti- *ute.! The ocelli are absent in the females of certain insects, as in the Mutillidz ; 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 court- ship, 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. Besices the complex structures at the apex of the abdomen, which ought perhaps to be ranked as primary organs,” ‘‘ it is aston- ishing,’’ as Mr. B. D. Walsh® has remarked, ‘‘ how many dif- ferent organs are worked in by nature for the seemingly ins ig- nificant object of enabling the male to grasp the female firmly.’’ The mandibles or jaws are sometimes used for this purpose; thus the male Corydalis cornutus (a neuropterous insect in some degree allied to the Dragon-flies, etc.) has immense curved jaws, many times longer than those of the female; and 1 Sir J. Lubbock, “Transact. Linnean Soc.” vol. xxv. 1866, p. 484. With respect to the Mutillidz see Westeosd, “ Modern Class. of Insects,” vol. ii. p. 213. ? These organs in the male often differ in closely allied species, and afford excellent specific characters. But their importance, from a functional point of view, as Mr. R. MacLachlan has remarked to me, has prob- ably been overrated. It has been suggested that slight differences 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- stance, Bronn, “* Geschichte der Natur,” B. ii. 1843, s. 1643 and Westwood, ** Transact. Ent. Soc.’’ vol. iii. 1842, p. 195) of distinct species having been observed in union. Mr. MacLachlan informs me (vide “ Stett. Ent. Zeitung,” 1867, s. 155) that when several species ot Phryganida, which present strong- ly pronounced differences of this kind, were confined together by Dr. Aug. Meyer, they coupled, and one pair produced fertile ova. ’ “The Practical Entomologist,” Philae delphia, vol. ii. May, 1867, p. 88. - ———4 204 THE DESCENT OF MAN. [PART It, they are smooth instead of being toothed, so that he is thus en- abled to seize her without injury.‘ One of the stag-beetles of North America (Zucanus elaphus) uses his jaws, which are much larger than those of the female, for the same purpose, but probably likewise for fighting. In one of the sand-wasps (Ammophila) the jaws in the two sexes are closely alike, but are used for widely different purposes: the males, as Prof. Westwood observes, ‘‘ are exceedingly ardent, seizing their partners round the neck with their sickle-shaped jaws ;’’® while the females use their organs for burrowing in sand-banks and making their nests. The tarsi of the front legs are dilated in many male beetles, or are furnished with broad cushions of hairs; 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 fe- male. It is a much more un- usual circumstance that the female of some water-beetles (Dytiscus} have their elytra deeply grooved, and in Acithus sulcatus thickly set with hairs, as an aid to the male. The females of some othet water-beetles (Hydroporus) have their elytra punctured for the same purpose. In the male of Cradbro cribrarius (fig. 9), it is the tibia which is dilated into a broad horny plate, with minute membraneous dots, giving to it a singular ap- pearance like that of a riddle.? Ir the male of Penthe (a genvs of beetles) a few of the middle jo‘nty of the antenne are dilated and ‘ur- nished on the inferior surface with cushions of hair, exactly Fic. 9.—Crabro cribrarius. Upper figure, male ; lower figure, female. tions between the sulcated or punctured ar ? the quite smooth elytra have been observed See Dr. H. Schaum, as quoted in the “‘ Zo- ologist,” vol. v.—vi. 1847-48, p. 1896. Also Kirby and Spence, ‘* Introduction to Ento- 4 Mr. Walsh, ibid. p. 107. 5 ** Modern Classification of Insects,” vol. ii. 1840, pp. 205, 206. Mr. Walsh, who called my attention to the double use of the jaws, says that he has repeatedly observed this fact. 6 We have here a curious and inexplicable case of dimorphism, for some of the females of four European species of Dytiscus, and of certain species of Hydroporus, have their elytra smaoth ; and no intermediate grada- mology,” vol. iii. 1826, p. 305. 3 7 Westwood, ‘* Modern Class.” vol. ii. p. 193. The following statement about Penthe, and others in inverted commas, are taken from Mr. Walsh, ‘‘ Practical. Entomologist,” Philadelphiz, vol. i. p. 88 J CHAP, X.} INSECTS. 295 like those on the tarsi of the Carabidz, ‘‘ 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 embrace the neck of the female.’’ Lastly, in the males of many insects, the legs are furnished with pecu- liar spines, knabs or spurs; or the whole leg is bowed or thickened; but this is by no means ‘nvariably a sexual character ; or one pair or all three 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 Carabidous beetle, Eurygnathus,® we have the case, unique as far as known to Mr. Wollaston, of the head of the fe- B male being much broader and larger, thoughina §~ variable degree, than that of the male. Any num- ber of such cases could be given. They abound in the Lepidoptera: one of the most extraordi- ‘nary is that certain male’ butterflies have their forelegs more or less atrophied, with the tibize and tarsi reduced to mere rudimentary knobs. The wings, also, in the two sexes often diffe. in neuration,!? and sometimes considerably in out- line, as in the Avicoris epitus, which was shown to me in the British Museum by Mr. A. Butler. The males of certain South Americar butterflies have tufts of hair on the margins of the wings, and horny excrescences on the discs of the pos- 4c" n apes terior pair.’ In several British butterflies, as {much enlarged). shown by Mr. Wonfor, the males alone are in male: lower figure, parts clothed with peculiar scales. ene The use of the bright light of the female glow-worm has been subject to much discussion. The male is feebly lumin- Qus, as are the larvae and even the eggs. It has been sup- ® Kirby and Spence, “*Introduct.” etc. Shuckard, ‘‘ Fossorial Hymenop.” 1837, pp. vol. ili. pp. 332-336. 39- 43) differ in neuration psec = to sex. ® “Insecta Maderensia,” 1854, p. 20. ‘HH. W. Bates, in “Journal of Proc, 410 E. Doubleday, ‘* Annals and Mag. of Linn. Soc.” vol. vi. 1862, p. 74. Mr. Won- Nat. Hist.” vol. i. 1848, p. 379 I may add for’s observations are quoted in ‘‘ Popular that the wings ix certain Hymenoptera (see Science Review,” 1868, p. 343- 206 THE DESCENT OF MAN. (PART 1. posed by some authors that the light serves to frighten away enemies, and by others to guide the male to the female. At last, Mr. Belt ' appears to have solved the difficulty : he finds that all the Lampyridz which he has tried are highly dis- tasteful to insectivorous mammals and birds. Hence it is in accordance with Mr. Bates’s view, hereafter to be explained, that many insects mimic the Lampyridz closely, in order to be mistaken for them, and thus to escape destruction. He further believes that the luminous species profit by being at once recognized as unpalatable. It is probable that the same ex- planation may be extended to the Elaters, both sexes of which are highly luminous. It is not known why the wings of the fe- male glow-worm have not been developed; but in her present state she closely resembles a larva, and as larvie 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 larve themselves are likewise luminous. Difference in Size between the Sexes.—With insects of all kinds the males are commonly smaller than. the females; and this difference can often be detected even in the larval state. So considerable is the difference between the male and female cocoons of the silk-moth (Bombyx mort), that in France 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 enor- mous 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 attend- ing to the development of the caterpillars of Bombyx cynthia and yamamat, and especially to that of some dwarfed. caterpillars reared from a second brood on unnatural food, ‘‘ that in pro- portion as the individual moth is finer, so is the time required for its metamorphosis longer ; and for this reason the female, which is the larger and heavier insect, from having to carry her numerous eggs, will be preceded by the male, which is smaller and has less to mature.’’ 4 Now, as most insects are short-lived, and as they are exposed to many dangers, it would manifestly be advantageous to the female to be impregnated as soon as possible. ‘This end would be gained by the males being first matured in large numbers ready for the advent of the 42 ‘The Naturalist in Nicaragua,” 1874, 23 Robinet, “ Vers a Sole,” 1848, p. 207. Pp. 316-320. Onthe phosphorescence of the 44 ‘‘ Transact. Ent. Soc,” 3d series, vol. Ve eggs, see “‘ Annals and Mag. of Nat. Hist.” p. 486, 1871,” Nov., p. 372+ CHAP. X.] INSECTS, 297 females ; and this again would naturally follow, as Mr. A. R. Wailace has remarked,” through natural selection; for the smaller males would be first matured, and thus would procreate a large number of offspring which would inherit the reduced size of their male parents, while the larger males, from being matured later, would leave fewer offspring. There are, however, exceptions to the rule of male insects being smaller than the females, and some of these exceptions are intelligible. Size and strength would be an advantage to the males which fight for the possession of the females; and in _these cases, as with the stag-beetle (Lucanus), the males are larger than the females. There are, however, other beetles which are not known to fight together, of which the males exceed the females in size, and the meaning of this fact is not known ; but in some of these cases, as with the huge Dynastes and Megasoma, we can at least see that there would be no necessity for the males to be smaller than the females, in order to be matured before them, for these beetles are not short-lived, and there would be ample time for the pairing of the sexes. So again, male dragon-flies (Libellulidz) are sometimes sensibly larger, and never smaller, than the females ; and, as Mr. Mac- Lachlan believes, they do not generally pair with the females until a week or fortnight has elapsed, and until they have assumed their proper masculine colors. But the most curious case, showing 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 among the Bees, the males of Apis mellifica, Anthidium manicatum, and Anthophora acervorum, and among the Fos- sores, the males of the AZethoca ichneumonides are larger than the females. ‘The explanation of this anomaly is that a mar- riage flight is absolutely necessary with these species, and the male requires great strength and size in order to carry the female through the air. Increased size has here been acquired in opposition to the usual relation between size and the period of development, for the males though larger, emerge before the smaller females. 36 « Journal of Proc. Ent. Soc.” Feb. 4, size of the sexes, see Kirby and Spence, 1867, p. Lxxi. ibid. vol. iii. p. 300; on the duration of life »4° For this and other statements on the in insects, see p. 344. ~ 298 THE DESCENT OF MAN. (PAR? it 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, Zhysanura.—The members of this lowly organized order are wingless, dull-colored, minute insects, with ugly, almost misshapen heads and bodies. Their sexes do not differ ; but they are interesting as showing us that the males pay sed- ulous court to the females even low down in the animal scale. Sir J. Lubbock ™ says: ‘It is very amusing to see these little creatures (Smynthurus luteus) coquetting together. ‘The male, which is much smaller than the female, runs round her, and they butt one another, standing face to face, and moving back- ward and forward like two playful lambs. Then the female pre- tends to run away and the male runs after her with a qveer appearance of anger, gets in front and stands facing her agai. , then she turns coyly round, but he, quicker and more active, scuttles round too, and seems to whip her with his antennez ; then for a bit they stand face to face, play with their antenne, and seem to be all in all to one another.”’ Order, Diptera (Flies).—The sexes differ little in color. The greatest difference, known to Mr. F. Walker, is in the genus Bibio, in which the males are blackish or quite black, and the females obscure brownish-orange. The genus Elaphomyia, dis- covered by Mr. Wallace *in New Guinea, is highly remarkable, as the males are furnished with horns, of which the females are quite destitute. The horns spring from beneath the eyes, and curiously resemble those of a stag, being either branched or pal- mated. In one of the species they equal the whole body in length. They might be thought to be adapted for fighting, but as in one species they are of a beautiful pink color, edged with black, with a pale central stripe, and as these insects have altogether a very elegant appearance, it is perhaps more prob- able that they serve as ornaments. ‘That the males of some Diptera fight together is certain; for Prof. Westwood ” has several times seen this with the Tipule- The males of other Diptera apparently try to win the females by their music: H. Miiller ® watched for some time two males of an Eristalis court- ing a female; they hovered above her, and flew from side to side, making a high humming noise at the same time. Gnats_ 17 See ‘‘The Transactions of the Lin- 49 ‘* Modern Classification of insects,” vol. pe Society,” volume xxvi. 1868, page ii. 1840; p- 526. 296. 20 Anwendung, etc., ‘Verh, d. n.. V. 18 “The Malay Archipelago,” vol. ii. 1869, Jahrg.” xxix. p. 80, Mayer, in ‘* Americas P. 313. Naturalist,” 1874, p. 236, -_-_—- ~~ a ee CHAP. X.] HEMIPTERA AND HOMOPTERA, 299 and mosquitoes (Culicidz) also seem to attract each other by humming; and Prof. Mayer has recently ascertained that the hairs on the antennz of the male vibrate in unison with the notes of a tuning-fork, within the range of the sounds emitted by the female. The longer hairs vibrate sympathetically with the graver notes, and the shorter hairs with the higher ones. Landois also asserts that he has repeatedly drawn down a wholv swarm of gnats by uttering a particular note. It may be added that the mental faculties of the Diptera are probably higher than in most other insects, in accordance with their highly developed nervous system. *! Order, Hemiptera (Field-Bugs).—Mr. J. W. Douglas, who has particularly attended to the British species, has kindly given me an account of their sexual differences. The males of some species are furnished with wings, while the females are wing- less ; the sexes differ in the form of their bodies, elytra, antennz, and tarsi; but, as the signification of these differences are un- known, they may be here passed over. ‘The females are gener- ally larger and more robust than the males... With British, and, as far as Mr. Douglas knows, with exotic species, the sexes do not commonly differ much in color; but in about six British species the male is considerably darker than the female, and in about four other species the female is darker than the male. Both sexes of some species are beautifully colored ; and as these insects emit an extremely nauseous odor, their conspicuous colors may serve as a signal that they are unpalatable to insec- tivorous animals. In some few cases their colors appear to be directly protective; thus Prof. Hoffmann informs me that he could hardly distinguish a small pink and green species from the buds on the trunks of lime-trees, which this insect frequ nts. Some species of Reduvidz make a stridulating noise ; ai.d, in the case of Pirates stridulus, this is said* to be effected by the movement of the neck within the pro-thoracic cavity. Accord- ing to Westring, Reduvius personatus also stridulates. But I have no reason to suppose that this is a sexual character, except- ing that with non-social insects there seems to be no use for sound-producing organs, unless it be as a sexual call. Order, Homoptera.—Everyone who has wandered in a tropi- cal forest must have been astonished at the din made by the male Cicadz. The females are mute; as the Grecian poet 22See Mr. B. T, Lowne’s interesting culiar plaintive note, and that this sound work, ‘‘On the Anatomy of the Blow-fly, causes other flies to disappear.” Musca vomitoria,” 1870, p. 14. Heremarks 22 Westwood, ‘‘ Modern Class. of Insects,” (P- 33) that “the captured flies utter ape vol. i p. 473 : & er 300 THE DESCENT OF MAN, (PART 11. Xenarchus says, *‘ Happy the Cicadas live, since they all have voiceless wives.’’ The noise thus made could be plainly heard on board the Beagle, when anchored at a quarter of a mile from the shore of Brazil; and Captain Hancock says it can be heard at the distance of a mile. ‘The Greeks formerly kept, and the Chinese now keep, these insects in cages for the sake of their song, so that it must be pleasing to the ears of some men. The Cicadidez usually sing during the day, while the Fulgoride appear to be night-songsters. The sound, according to Landois,™ is produced by the vibration of the lips of the spiracles, which are set into motion by a current of air emitted from the trachee; but this view has lately been disputed. Dr. Powell appears to have proved” that it is produced by the vibration of a membrane, set into action by aspecial muscle. In the living insect, while stridulating, this membrane can be seen to vibrate; and in the dead insect the proper sound is heard, if the muscle, when a little dried and hardened, is pulled with the point of a pin. In the fe- male the whole complex musical apparatus is present, but is much less developed than in the male, and is never used for producing sound. With respect to the object of the music, Dr. Hartman, in speaking of the Cicada septemdecim of the United States, says, ‘¢the drums are now (June 6 and 7, 1851) heard in all direc- tions. This I believe to be the marital summons from the males. Standing in thick chestnut sprouts about as high as my thead, where hundreds were around me, I observed the females coming around the drumming males.’’ He adds: ** This season (August, 1868) a dwarf pear-tree in my garden produced about fifty larvee of Circ. pruinosa ; and I several times noticed the females to alight near a male while he was uttering his “ clanging notes.’’ Fritz Miiller writes to me from South Brazil that he has often listened to a musical contest between two or three males of aspecies with a particularly loud voice, seated at a consider- able distance from each other: as soon as one had finished his song, another immediately began, and then another. As there is so much rivalry between the males, it is probable th-t the females not only find them by their sounds, but that, like femate 23 These particulars are taken from West- 25:°*Transact. New Zealand Institute,” wood’s ‘’ Modern Class. of Insects,” vol. ii, vol. v. 1873, p. 286. 1840, p. 422. See also, on the Fulgoride, 26 [ am indebted to Mr. Walsh for haying Kirby and Spence, * Introduct.” vol. ii. p. sent me this extract froma ‘Journal of a 401. Doings of Cicada Septem fecim”’ by ‘Dr 34 «4 Zeitschrift fiir wissenschaft Zoolog.” Hartman. B. avii. 1867, 5. 152-158. enap, x.] ORTHOPTERA. 301 birds, they are excited or allured by the male with the rnost attractive voice. Ihave not heard of any well-marked cases of ornamental differences between the sexes of the Homoptera. Mr. Douglas informs me that there are three British species in which the male is black or marked with black bands, while the females are pale-colored or obscure. _ Order, Orthoptera (Crickets and Grasshoppers).—The males in the three saltatorial families in this Order are remarkable for their musical powers, namely, the Achetidz, or crickets, the Locustidee, for which there is no equivalent English name, and the Acridiidz, or grasshoppers. The stridulation produced by some of the Locustidz is so loud that it can be heard dur- ing the night at the distance of a mile;* and that made by certain species is not un- Ff musical even to the human {| ear, so that the Indians on the Amazons keep them in wicker cages. All observers agree that the sounds serve either to call or excite the mute females.. With respect to the migratory locusts of Russia, Kérter has given an Fic. _11.—Gryllus campestris (from Lan- interesting case of selection ##). Righthand figure, under side of part of by the female of a male. teeth. s¢. Left-hand figure, upper surface of y i wing-cover, with the projecting, smooth nerve The males of this Species ure, 7, across whieh the teeth (sz) are scraped. (Pachytylus migratorius) while coupled with the female stridulate from anger or jealousy if approached by other males. The house-cricket when sur- prised at night uses its voice to warn its fellows.*® In North America the Katy-did (Platyphyllum concavum, one of the Lo- custidz) is described ® as mounting on the upper branches of a tree, and in the evening beginning ‘‘ his noisy babble, while rival notes issue from the neighboring trees, and the groves re- sound with the call of Katy-did-she-did the livelong night.’’ Mr. Bates, in speaking of the European field-cricket (one of 87 Guilding, Trans. Linn. Soc., vol. xv. 154. 29 Gilbert White, “Nat. Hist. of Sew %€ | state this on the authority of Képpen, borne,” vol. ii. 1825, p. 262. “U-ber die Heuschrecken in Siidrussland,” 39 Harris, ‘“*Insects of New England,” 1866, p. 32, for I have in vain endeavored 1842, p. 128. @ procure Kérte’s work. a 262 THE DESCENT OF MAN. [PART tt the Achetidz), says, ‘‘the male has been observed to place himself in the evening at the entrance of his burrow, and strid- ulate until a female approaches, when the louder notes are suc- ceeded by a more subdued tone, while the successful musician caresses with his antennz the mate he has won.’’*! Dr. Scud- der was able to excite one of these insects to answer him, by rubbing on a file with a quill.” In both sexes a remarkable auditory apparatus has been discovered by Von Siebold, situated in the front legs.* In the three Families the sounds are differently produced. In the males of the Achetidz both wing-covers have the same apparatus ; and this in the field-cricket (Gryllus campestris, fig. 11) consists, as described by Landois,* of from 131 to. 138 sharp, transverse ridges or teeth (sf) on the under side of one of the nervures of the wing-cover. ‘This toothed nervure is rapidly scraped across a projecting, smooth, hard nervure (7) on the upper surface of the opposite wing. First one wing is rubbed over the other, and then the movement is reversed. Both wings are raised a little at the same time, so as to increase the resonance. In some species the wing-covers of the males are furnished at the base with a talc-like plate. I here give a drawing (fig. 12) of the teeth on the under side of the nervure of another species of Gryllus, viz., G. of Nervare of Gayl domesticus. With respect to the formation of tus domesticus these teeth, Dr. Gruber has shown ® that they (from Landois). have been developed by the aid of selection, from the minute scales and hairs with which the wings and body are covered, and I came to the same conclusion with respect to those of the Coleoptera. But Dr. Gruber further shows that their development is in part directly due to the stimulus from the friction of one wing over the other. In the Locustide the opposite wing-covers differ from each other in structure (fig. 13), and the action cannot, as in the ast family, be reversed. The left wing, which acts as the bow, lies over the right wing, which serves as the fiddle. One - 4 The Naturalist on the Amazons, vol. i. 34 ** Zeitschrift net Wissenschaft. Zoolog.” 1863, p. 252. Mr. Bates gives a very interest- B. xvii. 1867, Ss. ing discussion on the gradations in the musi- 35 Were “ oda Class. of Insects,” cal apparatus of the three families. Seealso vol. 1 Westwood, Mod. Class. vol. ii. pp. 445 & 453. 36 4 Nice den Tonapparat der Locus- 32 ** Proc, Boston Soc. of Nat. Hist.” vol. tiden, ein Beitrag zum_ Darwinismus,” «i. April, 1868. ‘‘ Zeitsch. fiir Wissensch. Zoolog.” B. xxii. 33 **Nouveau Manuel d’Anat. Comp.” 1872, p. 100. (French translat.), tem. i. 1850, p. 567. CHAP. X.]} ORTHOPTERA, 303 of the nervures (a) on the under surface of the former is finely serrated, and is scraped across the prominent nervures on the upper surface of the opposite or right wing. In our British Phasgonura viridissima it appeared to me that the serrated nervure is rubbed against the rounded hind-corner of the oppo- site wing, the edge of which is thickened, colored brown, and very sharp. In the right wing, but not in the left, there is a little plate, as transparent as talc, surrounded by nervures, and GU, ‘ eit co‘ ri Me ile \N-Re SRO YN Fic. 13.-~Chloroccelus Tanana (from Bates). a, 4. Lobes of opposite wing-covers. called the speculum. In Zphippiger vitium, a member of this same family, we have a curious subordinate modification ; for the wing-covers are greatly reduced in size, but ‘ the posterior part of the pro-thorax is elevated into a kind of dome over the wing-covers, and which has probably the effect of increasing the sound.’’ * We thus see that the musical apparatus is more differentiated er specialized in the Locustide (which include I believe, the #7 Westwood. “‘ Modern Class. of Insects,” vol. i. p. 452, ’ 304 THE DESCENT OF MAN. [PART IL most powerful performers in the Order), than in the Achetide, in which both wing-covers have the same structure and the same function.® Landois, however, detected in one of the Locustidz, namely, in Decticus, ashort and narrow row of small teeth, mere rudiments, on the inferior surface of the right wing- cover, which underlies the other and is never used as the bow. I observed the same rudimentary structure on the under side of the right wing-cover in Phasgonura viridissima. Hence we may infer with confidence that the Locustide are descended from a form in which, as in the existing Achetidz, both wing- covers had serrated: nervures on the under surface, and could be indifferently used as the bow; but that in the Locustide the two wing-covers gradually became differentiated and per- fected, on the principle of the exclusively as the bow, and the other as the fiddle. Dr. Gruber takes the same view, and has shown that rudimentary teeth are commonly found on the in- ferior surface of the right wing. By what steps the more simple apparatus in the Achetidee orig- Fig. 14.—Hind-leg of Stenobothrus pra- inated, we do not know, but it torum; 7, the stridulating ridge; lower is probable that the basal por- cee omiog ridge, much tions of the wing-covers origi- nally overlapped each other as they do at present ; and that the friction of the nervures pro- duced a grating sound, as is now the case with the wing-covers of the females.*® A grating sound thus occasionally and acci- dentally made by the males, if it served them ever so little as a love-call to the females, might readily have been intensified through sexual selection, by variations in the roughness of the nervures having been continually preserved. In the last and third Family, namely, the Acridiidz, or grasshoppers, the stridulation is produced in a very different manner, and, according to Dr. Scudder, is not so shrill asin the preceding Families. The inner surface of the femur (fig. 14, 7) is furnished with a longitudinal row of minute, elegant, lancet- DAS: DiS nf 88 Landois, “‘Zeitsch. f. Wiss. Zoolog.” Zum concavum, ‘‘when captured, makes a B. xvii. 1867, S. I2I, 122. feeble grating noise by shuffling her wing- 89 Mr. Walsh also informs me that he covers together,” has noticed that the female of the Platyphyl- division of labor, the one to act EE —— /CHAP. X. ‘ ORLHOPTERA, 205 shaped, elastic teeth, from 85 to 93 in number; and these are scraped across the sharp, projecting nervures on the wing- covers, which are thus made to vibrate and resound. Harris“ says that when one of the males begins to play, he first ‘« bends the shank of the hind-leg beneath the thigh, where it is lodged in a furrow designed to receive it, and then draws the leg briskly up and down. He does not play both fid: Pic. 15.—Pneumora (from specimens in the British Museum). Upper figure, male, lower figure, female. tiles together, but alternately, first upon one and. then on the other.’’ In many species the base of the abdomen is hollowed out into a great cavity which is believed to act as a resounding board. In Pneumora (fig. 15), a South African Landois, ibid.s. 113. 44“ Tusects of New England,” 1842, p. 133. 306 THE DESCENT OF MAN. (PART n. genus belonging to the same family, we meet with a new and remarkable modification ; in the males a small notched ridge projects obliquely from each side of the abdomen, against which the hind femora are rubbed.” As the male is furnished with wings (the female being wingless), it is remarkable that the thighs are not rubbed in the usual manner against the wing- covers ; but this may perhaps be accounted for by the unusually small size of the hind-legs. I have not been able to examine the inner surface of the thighs, which, judging from analogy, would be finely serrated. ‘The species of Pneumora have been more profoundly modified for the sake of stridulation than any other orthopterous insect ; for in the male the whole body has been converted into a musical instrument, being distended with air, like a great pellucid bladder, so as to increase the reson- ance. .Mr. Trimen informs me that at the Cape of Good Hope these insects make a wonderful noise during the night. In the three foregoing families the females are almost always destitute of an efficient musical apparatus. But there are a few exceptions to this rule, for Dr. Gruber has shown that both sexes of Ephippiger vitium are thus provided, though the organs differ in the male and female to a certain extent. Hence we cannot suppose that they have been transferred from the male to the female, as appears to have been the case with the sec- ondary sexual characters of many other animals. They must have been independently developed in the two sexes, which no doubt mutually call to each other during the season of love, In most other Locustidz (but not according to Landois in Decticus) the females have rudiments of the striduiatory organs proper to the male, from whom it is probable that these have been transferred. Landois also found such rudiments on the under surface of the wing-covers of the female Achetidz, and on the femora of the female Acridiide. In the Homoptera, also, the females have the proper musical apparatus in a func- tionless state ; and we shall hereafter meet in other divisions of the animal kingdom with many instances of structures proper to the male being present in a rudimentary condition in the female. Landois has observed another important fact, namely, that in the females of the Acridiide, the stridulating teeth on the femora remain throughout life in the same condition in which they first appear during the larval state in both sexes. In the males, on the other hand, they become further developed. and $3 Westwood, “‘ Medern Classification,” vel i. p. 462s CHAP, x.) ORTHOPTERA. 407 acquire their perfect structure at the last moult, when the insect is mature and ready to breed. From the facts now given, we see that the means by which the males of the Orthoptera produce their sounds are extremely diversified, and are altogether different from those employed by the Homoptera.“ But throughout the animal kingdom we often find the same object gained by the most diversified means ; this seems due to the whole organization having undergone multifarious changes in the course of ages, and as part after part varied different variations were taken advantage of for the same general purpose. ‘The diversity of means for producing sound in the three families of the Orthoptera and in the Homoptera impresses the mind with the high importance of these structures to the males, for the sake of calling or alluring the females. We need feel no surprise at the amount of modi- fication which the Orthoptera have undergone in this respect, as we now know, from Dr. Scudder’s remarkable discovery, that there has been more than ample time. This naturalist has lately found a fossil insect in the Devonian formation of New Brunswick, which is furnished with ‘‘ the well-known tympanum or stridulating apparatus of the male Locustidz.”’ The insect, though in most respects related to the Neuroptera, appears, as is so often the case with very ancient forms, ta connect the two related Orders of the Neuroptera and Orthop- tera. I have but little more to say on the Orthoptera. Some ol the species are very pugnacious. When two male field-crickets (Gryllus campestris) are confined together, they fight till cne kills the other; and the species of Mantis are described as manceuvring with their sword-like front limbs, like hussars with their sabres. The Chinese keep these insects in little bamboo cages, and match them like game-cocks.* With respect to color, some exotic locusts are beautifully ornamented; the posterior wings being marked with red, blue, and black; but as throughout the Order the sexes rarely differ much in color, ‘it is not probable that they owe their bright tints to sexual selection. Conspicuous colors may be of use to these insects, by giving notice that they are unpalatable. Thus it has been observed “ that a bright-colored Indian locust was invariably 43 Landois has recently found in certain ni “Transact. Ent. Soc.” 3d series, vol, Orthoptera rudimentary structures closely ii. (‘ Journal of Proceedings,” p. 117.) similar to the sound-producing organs in the as Westwood, “Modern Class. of In- Homoptera ; and this is a surprising ait sects,” vol. i. p. 427; for crickets, P 445- See “ Zeitschr. fiir Wissensch, oolog.” B. 46 Mr. Ch. Horne, in “ Prog. Ent. Soc. axii. Heft. 3, 1871, p. 348, May 3, 1869, p. xii, —_— ———, 308 THE DESCENT OF MAN. [PART It. rejected when offered to birds and lizards. Some cases, how- ever, are known of sexual differences of color in this Order. The male of an American cricket is described as being as white as ivory, while the female varies from almost white to greenish-yellow or dusky. Mr. Walsh informs me that the adult male of Spectrum femoratum (one of the Phasmidz) ‘* is of a shining brownish-yellow color; the adult female being of a dull, opaque, cinereous brown ; the young of both sexes being green.’’ Lastly, I may mention that the male of one curious kind of cricket “ is furnished with ‘‘ along membranous append- age, which falls over the face like a veil;’’ but what its use may be, is not known. Order, Weuroptera.—Littie need here be said, except as to color. In the Ephemeride the sexes often differ slightly in their obscure tints; but it is not probable that the males are thus rendered attractive to the females. The Libellulidz, or dragon-flies, are ornamented with splendid green, blue, yellow, and vermilion metallic tints; and thesexes often differ. ‘Thus, as Prof. Westwood remarks,” the males of some of the Agrionide ‘‘are of a rich blue with black wings, while the females are fine green with colorless wings.’’ But in Agrion Raméburit these colors are exactly reversed in the two sexes. * In the extensive North American genus of Heterina, the males alone have a beautiful carmine spot at the base of each wing. In Anax junivs the basal part of the abdomen in the male is a vivid ultramarine blue, and in the female grass-green.. In the allied geuus Gomphus, on the other hand, and in some: other genera, the sexes differ but little in color. In closely allied forms throughout the animal kingdom, similar cases of the sexes differing greatly, or very little, or not at all, are of ‘frequent occurrence. Although there is so wide a difference in color between the sexes of many Libellulide, it is often difficult to say which is the more brilliant ; and the ordinary coloration of the two sexes is reversed, as we have just seen, in one species of Agrion. It isnot probable that their colors in any case have been gained as a protection. Mr. MacLachlan, who has closely attended to this family, writes to me that dragon- -flies—the tyrants of the insect-world—are the least liable of any insect to 47 The Gcanthus nivalis. Harris, “In- 4° B. D. Walsh, the “ Pseudo-neuroptera sects of New England,” 1842. p. 124.. The of Illinois,” in “Proc. Ent. Soc. of Phila- two sexes of CE. pellucidus of Europe dif- delphia,” 1862, p. 361. fer, as I hear from Victor Carus, in nearly 50 ““ Modern Class. ” vol. ii. Pp. 37: the same manner. 51 Walsh, ibid. p. 381. Iam reid to 48 Platyblemnus: Westwood, “ Modern this naturalist for the following facts om Class.” vol. i. p. 447: Hetzrina, Anax, and Gomphus. ; ; d ‘ j “CHAP, X.} NEUROPTERA. 3209 be attacked by birds or other enemies, and he believes that their bright colors serve as a sexual attraction. Certain dragon- flies apparently are attracted by particular colors. Mr. Patter- son observed ** that the Agrionide, of which the males ae blue, settled in numbers on the blue float of a fishing line, while two other species were attracted by shining white colors. It is an interesting fact, first noticed by Schelver, that, in several genera belonging to two sub-families, the males on first emergence from the pupal state are colored exactly like the females; but that their bodies in a short time assume a con- spicuous milky-blue tint, owing to the exudation of a kind of oil, soluble in ether and alcohol. Mr. MacLachlan believes that in the male of Lzbe//ula depressa this change of color does not occur until nearly a fortnight after the metamorphosis, when the sexes are ready to pair. _, Certain species of Neurothemis present, according to Brauer, acurious case of dimorphism, some of the females having ordinary wings, while others have them ‘‘ very richly netted, as in the males of the same species.’’ Brauer ‘‘ ex- plains the phenomenon on Darwinian principles by the suppo- sition that the close netting of the veins is a secondary sexual character in the males, which has been abruptly transferred to some of the females instead of, as generally occurs, to all of them.’’ Mr. MacLachlan informs me of another instance of dimorphism in several species of Agrion, in which some indi- viduals are of an orange color, and these are invariably females. This is probably a case of reversion ; for in the true Libellule, when the sexes differ in color, the females are orange or yellow ; so that, supposing Agrion to be descended from some primor- dial form which resembled the typical Libellulee in its sexual characters, it would not be surprising that a tendency to vary an this manner should occur in the females alone. Although many dragon-flies are large, powerful, and fierce insects, the males have not been observed by Mr. MacLachlan to fight together, excepting, as he believes, in some of the smaller species of Agrion. In another group in this Order, namely, the ‘Termites, or white ants, both sexes at the time of swarming may be seen running about, ‘‘ the male after the female, sometimes two chasing one female, and contending with great eagerness who shall win the prize.’’ 4 The Azropos 62 Trans. Ent. Soc., vol. i., 1836, p. lxxxi. 5* Kirby and Spence, ‘* Introduct, te Ear ®3 See abstract in the ‘Zoological Rec- tomology,” vol. i. 1818, p. 35. @id” for 1867, p. 450 310 THE DESCENT OF MAN. (PART 11 pulsatorius is said to make a nvise with its jaws, which is answered by other individuals.’’ ® Order, H/ymenoptera.—That inimitable observer, M. Fabre,® in describing the habits of Cerceris, a wasp-like insect, remarks that ‘‘ fights frequently ensue between the males for the pos- session of some particular female, who sits an apparently uncon- cerned beholder of the struggle for supremacy, and, when the victory is decided, quietly flies away in company with the conqueror.’’ Westwood™ says that the males of one of the saw-flies (Tenthredinz) ‘‘ have been found fighting together, with their mandibles locked.’’ As M. Fabre speaks of the males of Cerceris striving to obtain a particular female, it may be well to bear in mind that insects belonging to this Order have the power of recognizing each other after long intervals of time, and are deeply attached. For instance, Pierre Huber, whose accuracy no one doubis, separated some ants, and when, after an interval of four months, they met others which had formerly belonged to the same community, they recognized and caressed one another with their antenne. Had they been strangers they would have fought together. Again, when two communities engage in a battie, the ants on the same side sometimes attack each other in the general confusion, but they soon perceive their mistake, and the one ant soothes the other.* In this Order slight differences in color, according to sex, are common, but conspicuous differences are rare except in the family of Bees; yet both sexes of certain groups are so brill- iantly colored—for instance in Chrysis, in which vermilion and metallic greens prevail—that we are tempted to attribute the result to sexual selection. In the Ichneumonide, accord- ing to Mr. Walsh,® the males are almost universally lighter- colored than the females. On the other hand, in the Ten- thredinidz the males are generally darker than the females. In the Siricide the sexes frequently differ; thus the male of Sirex juvencus is banded with orange, while the female is dark purple ; but it is difficult to say which sex is the more orna- mented: In Zyremex columbe the female is much brighter- colored than the male. Iam informed by Mr. F. Smith that the male ants of several species are black, the females being testaceous. 68 Houzeau, ‘Les Facultés Mentales,” the Entomological Society” for September Ctc., tom. i. Pp. 104 Jy 3863, p 169. 68 See an interesting article, ‘* The Writ- 8 Pp: Fides “* Recherches sur les Moeurs ings of Fabre,” in “ Nat. Hist. Review,” aes Fourmis,” 1870, pp. 150, 165. April, 1862, P. 122 59 ** Proc, Entomolog. Soc. of Philadele 87 See the ‘ ‘ Journal of the Proceedings of phia,” 1866, pp. 238-239. 5 | 4 CHAP. X.] HYMENOPTERA. 318 In the family of Bees, especially in the solitary species, as I hear from the same entomologist, the sexes often differ in color. The males are generally the brighter, and, in Bombus as well as in Apathus, much more variable in color than the females. In Axnthophora retusa the male is of a rich fulvous- brown, while the female is quite black ; so are the females of sev- eral species of Xylocopa, the males being bright yellow. On the other hand, the females of some species, as of Andrena fulva, are much brighter-colored than the males. Such differences in color can hardly be accounted for by the males being de- fenceless and thus requiring protection, while the females are well defended by their stings. H. Miiller, who has particu- larly attended to the habits of bees, attributes these differences in color in chief part to sexual selection. That bees have a keen perception of color is certain. Hesays that the males search eagerly and fight for the possession of the females; and he accounts through such contests for the mandibles of the males being in certain species larger than those of the females. In some cases the males are far more numerous than the fe- males, either early in the season, or at all times and places, or locally ; whereas the females in other cases are apparently in excess. In some species the more beautiful males appear to have been selected by the females, and in others the more beau- tiful females by the males. Consequently, in certain genera (Miiller, p. 42), the males of the several species differ much in appearance, while the females are almost indistinguishable ; in other genera the reverse occurs. H. Miiller believes (p. 82) that the colors gained by one sex through sexual selection have often been transferred in a variable degree to the other sex, just as the pollen-collecting apparatus of the female has often been transferred to the male, to whom it is absolutely use- less. Mutilla Europea makes a stridulating noise ; and according 60 ** Anwendung der Darwin’schen Lehre auf Bienen.” Verh. d. n. Jahrg. xxix. 64M, Perrier in his article, ‘‘ La Sélection sexuelle d’?aprés Darwin” (‘‘ Revue Scienti- fique,” Feb. 1873, p. 868), without apparently having reflected niuch on the subject, objects that as the males of social bees are known to be produced from unfertilized ova, they could not transmit new characters to their male offspring. This is an extraordinary objection. A female bee fertilized by a male, which presented some character facili- tating the union of the sexes, or rendering him more attractive to the female, would lay eggs which would produce only females ; but these young females would next year produce males; and will it be pretended that such males would not inherit the char- acters of their male grandfathers? To take a case with ordinary animals as nearly paral- lel 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 pre- tended that the grandchildren would not in- herit a tendency to blackness from their male grandfather? The acquirement of new characters by the sterile worker-bees is a much more difficult case, but I have endeav- ored to show in my “Origin of Species” how these sterile beings are subiected to the power of natural selection. 312 THE DESCENT OF MAN. {PART IL to Goureau ® both sexes have this power. He attributes the sound to the friction of the third and preceding abdominal segments, and I find that these surfaces are marked with very fine concentric ridges ; but so is the projecting thoracic collar, into which the head articulates, and this collar, when scratched with the point of a needle, emits the proper sound. It is rather surprising that both sexes should have the power of stridulating, as the male is winged and the female wingless. It is notorious that Bees express certain emotions, as of anger, by the tone of their humming; and, according to H. Miiller (p. 80), the males of some species make a peculiar singing noise while pur- suing the females. Order, Coleoptera (Beetles).—-Many beetles are colored 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 colors, which are often arranged in stripes, spots, crosses, and other elegant patterns. Such colors 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 recogni- tion, on thesame principle as the phosphorescence of the glow- worm. As with beetles the colors of the two sexes are gener- ally 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 well-marked secondary sexual characters. Blind beetles, which cannot, of course, behold each other’s beauty, never, as I hear from Mr. Waterhouse, Jr., exhibit bright colors, though they often have polished coats ; but the explanation of their obscurity may be that they gen- erally inhabit caves and other obscure stations. Some Longicorns, especially certain Prionidz, offer an exception to the rule that the sexes of beetles do not differ in color. Most of these insects are large and splendidly colored. The males in the genus Pyrodes,® which I saw in Mr. Bates’s 62 Quoted by Westwood, ** Modern Class. of Insects,” vol. ii. p. 214. 63 Pyrodes pulcherrimus, in which the sexes differ conspicuously, has been de- scribed 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 color between the sexes of beetles. Kirby and Spence (‘*Introduct. to Entomology,” vol, iii. p. 301) mention a Cantharis, Meloe, Rhagium, and the Leftura testacea; the male of the latter being testaceous. with a black thorax, and the female of a dull red all over. These two latter beetles belong to the family of Longicorns. Messrs. R. Trimen and Waterhouse, Jr., inform me of two Lamellicorns, viz., a Peritrichia and Trichius, the male of the latter being more cbscurely colored than the female. In 77iJus elon- gatus the male is black, and the female ab CHAP. x.] COLEOPTERA. 313 collection, are generally redder but rather duller than the females, the latter being colored 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 purple. In the genus Esmeralda thesexes differ so greatly in color 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 Prionidze in which the sexes differ are colored Fic. 16.—Chalcosoma atlas. Upper figure, aa (reduced) ; lower figure, female (nat, s1ze . more richly than the males, and this does not accord with the commor rule in regard to color, 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 quadru- peds, such as stags, rhinoceroses, etc., and are wonderful both from their size and diversified shapes. Instead of describing ways, as it is believed, of a dark blue color, is black, the female (the so-called O. rufe with a red thorax. The male, aiso, of Or- odds) having a rufous thorax. sodacna atra,as 1 he» from Mr. Walsh, , Sen (N)—Vol, 3 314 THE DESCENT OF MAN. [PART IL 3 ; ; i. Fic. 18.—Phangeus faunus. Fic. 20.—Onthophagus rangifer, enlarged. CHAP. x.] COLEOPTERA. 315 them, I have given figures of the males and females of some of the more remarkable forms. (Figs. 16 to 20.) The females generally exhibit rudiments of the horns in the form of small knobs or ridges; but some are destitute of even the slightest rudiment. On the other hand, the horns are nearly as well | developed in the female as in the male of Phaneus 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. In almost all cases the horns are remarkable from their excessive variability ; so that a graduated series can be formed from the most highly developed males to others so degenerate that they can barely be distinguished from the females. Mr. Walsh ™ found that in Phaneus carnifex the horns were thrice as long in some males as in others. Mr. Bates, after examin- ing above a hundred males of Onthophagus rangifer (fig. 20), thought that he had at last discovered a species in which the horns did not vary ; but further research proved the contrary. The extraordinary size of the horns, and their widely dif- ferent 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 suppose ® 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 suffh- cient 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 Copridz, did not find any 64“ Proc, Entomolog. Soc. of Philadel- © Kirby and Spence, “ Introduci. Ente phia,” 1864, p. 228. moleg.’’ vol. iii, p. 300, 31 THE DESCENT OF MAN. [PART IL marked aifference in this respect among well-developed indi- viduals. In Lethrus, moreover, a beetle belonging to the same great division of the Lamellicorns, the males are known to fight, but are not provided with horns, though their mandi- bles are much larger than those of the female. { The conclusion that the horns have been acquired as orna- ments is that which best agrees with the fact of their having been so immensely, yet not fixedly, developed—as shown by their extreme variability in the same species, and by their extreme diversity in closely allied 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 purpose. The males of Onzdvs furcifer (fig. 21) and of some other species of the genus are furnished with singular projections on their an- terior femora, and with a great fork or pair of horns on the lower surface of the thorax. Judging from other insects, these may aid the male in clinging to the female. Al- though the males have not even a trace of a horn on the upper surface of the body, yet the females plainly exhibit a rudiment of a single horn on the head (fig. 22, a), and of a crest (4) on the thorax. That the slight __. ... thoracic crest in the female is a rudiment me ed ee rete of a projection proper to the male, though entirely absent in the male of this particu- lar species, is clear: for the female of Aubas bison (a genus which comes next to Onitis) has a similar slight crest on the Fic. 22.—Left-hand figure, male of Onitis furcifer, viewed laterally. Right-hand figure, female, @. Rudiment of cephalic horn. 4. Trace of thoracic horn or crest. thorax, and the male bears a great projection in the same situation. So, again, there can hardly be a doubt that the CHAP. x.] COLEOPTERA, 217 little point (2) on the head of the female Onitis furcifer, as well as on the head of the females of two or three allied species, is a rudimentary representative of the cephalic horn, which is common tothe males of so many Lamellicorn beetles, as in Phanzeus (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. We may reasonably suspect that the males originally bore horns and transferred them to the females in a rudimentary con- dition, as in so many other Lamellicorns. Why the males subse- quently lost their horns, we know not; but this may have been caused through the principle of compensation, owing to the de- velopment of the large horns and projections on the lower sur- face ; and as these are confined to the males, the rudiments of the upper horns on the females would not have been thus obliterated. The cases hitherto given refer to the Lamellicorns, but the males of some few other beetles, belonging to two widely dis- tinct groups, namely, the Curculionidz and Staphylinidz, are furnished 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 Staphylinidz the horns of the males are extraordinarily variable in the same species, just as we have seen with the Lamellicorns. In Siagonium we have a case of dimorphism, for the males can be divided into two sets, differing greatly in the size of their bodies and in the development of their horns, without intermediate gradations. Ina species of Bledius (fig. Fic. 23.—Bledius taurus, magnified. Left-hand figure, male; right-hand figure, female, 23), also belonging to the. Staphylinide, Prof. Westwood states that, ‘‘male specimens can be found in the same locality in which the central horn of the thorax is very large, but the horns of the head quite rudimental; and others, in which the thoracic horn is much shorter, while the protu- berances on the head are long.’ Here we apparently have 6° Kirby and Spence, “‘Introduct. Ento- British Museum I noticed one male spect molog.” yol. iii. p. 329. ' men of Siagonium in an intermediate condi+ 67 “*Modern Classification of Insects,” tion, so that the dimorphism is not strict, vol. i. p. 172: Siagonium, p. 172. In the 318 THE DESCENT OF MAN. (PART 1L 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 (Zucanus cervus) the males of which emerge from the pupal state about a week before the other sex, so that several may often be seen pursuing the same female. At this season they engage in fierce conflicts. When Mr. A. H. Davis® inclosed 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 Lucanidz, as well as of the above- mentioned Leptorhynchus, are larger and more powerful insects than the females. The two sexes of Lethrus cephalotes (one of the Lamellicorns) inhabit the same burrow, and the male has larger mandibles than the female. If, during the 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 continually 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 de- posited ; and if she is removed, he becomes much agitated. 68 ‘The Malay Archipelago,” vol. ii, species, Kirby and Spence, ibid. vol. iii. p. 1869, p. 276. Riley, Sixth ‘Report on In- 314; and Westwood, ibid. vol. i. p. 187. sects of Missouri,’”’ 1874, p. 115. 70 Quoted from Fischer, in “‘ Dict. Class. : 69 ** Entomological Magazine,” vol. i. d’Hist. Nat” tom. x. p. 324 2833, D- 82, See also on the conflicts of this CHAP. X.] COLEOPTERA, 319. If the male is removed the female ceases all work, and, as M. Brulerie “ believes, would remain on the seme spot until she died. The great mandibles of the male Lucanidz are extremely variable both in size and structure, and in this re- spect resemble the horns on the head and thorax of many male Lamelli- corns and Staphylinide. A perfect series can be formed from the best- provided to the worst-provided or de- generate males. Although the mandi- bles of the common stag-beetle, and probably of many other species, are used as efficient weapons for fighting, it is doubtful whether their great size can thus be accounted for. We have seen that they are used by the Zucanus elaphus of North America for seizing the female. As they are so conspic- uous and so elegantly branched, and as owing to their great length they are not weil adapted for pinching, the sus- picion has crossed my mind that they may in addition serve as an ornament, like the horns on the head and thorax of the various species above described. The male Chiasognathus grantit of South Chile—a splendid beetle belong- ing to the same family—has enormous- ly developed mandibles (fig. 24); he is bold and pugnacious ; when threat- ened 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. Fic. 24.—Chiasognathus grantil, Sexual selection, which implies the [Swerfure, "ad, Soopers possession of considerable perceptive powers and of strong passions, seems to have been more effec tive with the Lamellicorns than with any other family of beetles. With some species the males are provided with weap- 74 * Ann. Soc. Entomolog. France,” 1866, as quoted in “‘ Journal of Travel,’’ by A. Mur way, 1868, p. 135+ 320 THE DESCENT OF MAN, [PART IL. ons for fighting ; some live in pairs and show mutual affec- tion; many have the power of stridulating when excited ; many are furnished with the most extraordinary horns, ap- parently for the sake of ornament; and some, which are diurnal in their habits, are gorgeously colored. Lastly, sev- eral of the largest beeties in the world belong to this family, which was placed by Linnzeus and Fabricius at the head of the Order.” Stridulating Organs.—Beetles belonging to many and widely distinct families possess these organs. The sound thus pro- duced 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, slightly raised surface, crossed by very fine, parallel ribs, sometimes so fine as to cause iridescent colors, and having a very elegant appearance under the microscope. In some cases, as with Typhceus, minute, bristly, or scale-like prominences, with which the whole surrounding surface is covered in approxi- mately parallel lines, could be traced passing into the ribs of the rasp. The transition takes place by their becoming con- fluent 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. Fic. 25.—Necrophorus (from Landois). ». 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) two parallel rasps (7, fig. 25) stand on the dorsal surface of the fifth abdominal segment, 72 Westwood, ‘‘ Modern Class.” vol. i. p. culionide,’’ “Annals and i of Nat 384. Hist.” vol. vi. 1860 P- 14. 73 Wollaston, ‘*On Certain Musical Cur- oHAr. X%.] COLEOPTERA. 321 each rasp“ consisting of 126 to 140 fine ribs. ‘These ribs are seraped against the posterior margins of the elytra, a small por- tion of which projects beyond the general outline. In many Crioceridz, and in Clythra 4-punctata (one of the Chrysome- lide), and in some Tenebrionidz, etc.,” 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 Curculionidee and Carabide“ the parts are completely reversed in position, for the rasps are seated on the inferior surface of the elytra, near their apices, or along their outer margins, and the edges of the abdominal segments serve as the scrapers. In Pelobius Her- manni (one of Dytiscide, 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 be- coming gradually finer at both ends, espe- cially at the upper end; when this insect is held under water or in the air, a stridu- lating noise is produced by the extreme Fic. 26.-—Hind-leg of horny margin of the abdomen being scraped Geotrupes | stercorarius é rom Landois). re against the rasps. Ina great number of long- . Rasp. c. Coxa. /f, horned beetles (Longicornia) the organs are {ime" * Tbe situated quite otherwise, the rasp being on the meso-thorax, which is rubbed against the pro-thorax ; Lan- dois counted 238 very fine ribs on the rasp of Cerambyx heros. Many Lamellicorns have the power of stridulating, and the organs differ greatly in position. Some species stridulate very ‘oudly, so that when Mr. F. Smith caught a Zyox sabulosus, a 74 Landois, ‘‘Zeitschrift fiir Wiss. Zoolog.” B. xvii. 1867, s. 127. 75 | 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 in- formation and specimens. I may add that my son, Mr. F. Darwin, finds that Devszes- tes murinus stridulates, but he searched in Vain for the apparatus. Scolytus has lately been described by Dr. Chapman asa stridu- lator, in the ‘* Entomologist’s Monthly Mag- azine,” vol. vi. p. 130. 76 Schiédte, translated in ‘* Annals and Mag. of Nat. Hist.” vol. xx. 1867, p. 37. 77 Westring has described (Kroyer, ** Nat- urhist. ‘Tidskrift,” B. ii. 1848-49, p. 334) the stridulating organs of these two, as well as in other families. In the Carabide I have examined Klaphrus uliginosus and Blethix sa multipunctata, sent to-me by Mr. Crotch, In Blethisa the transverse ridges on the furrowed border of the abdominal segment do not, as far as I could judge, come into play in scraping the rasps on the elytra, 322 THE DESCENT OF MAN. {PART 11 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 (7, fig. 26) the coxa of each hind-leg (having in G. stercorarius 84 ribs), which 1s scraped by a specially projecting part of one of the abdominal segments. In the nearly allied Copris luna- vis, an excessively narrow fine rasp runs along the sutural margin of the elytra, with another sharp rasp near the basal outer margin; 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, on the under surface of the elytra. Lastly, Westring states that in Omaloplia brunnea the rasp is placed on the pro-sternum, and the scraper on the meta-sternum, the parts thus occupy- ing the under surface of the body, instead of the upper sur- face, as in the Longicorns. We thus see that in the different coleopterous families the stridulating organs are wonderfully diversified in position, but not much in structure. Within the same family some species are provided with these organs, and others are destitute of them. This diversity is intelligible, if we suppose that origi- nally various beetles made a shuffling or hissing noise by the rubbing together of any hard and rough parts of their bodies which happened to be in contact; and that, from the noise thus produced being in some way useful, the rough surfaces were gradually developed into regular stridulating organs. Some beetles, as they move, now produce, either intentionally or unintentionally, a shuffling noise, without possessing any proper organs for the purpose. Mr. Wallace informs me that the Luchirus longimanus (a Lamellicorn, with the anterior legs wonderfully elongated in the male) ‘‘ makes, while moving, a low hissing sound by the protrusion 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 hissing sound is clearly due to a narrow rasp running along the sutural margin of each elytron; and I could likewise make the grating sound by rubbing the shagreened surface of the femur against the granulated margin of the corresponding elytron ; but I could not here detect any proper rasp; nor is it likely that I could have overlooked it in so large an insect. After 78 T am indebted to Mr. Walsh, of Illinois, for having sent me extracts from Leconte’s *¢ Introduction to Entomolugy,” pp. 101, 142. CHAP, X.} COLEOPTERA, 323 examining Cychrus, and reading what Westring has writ- ten about this beetle, it seems very doubtful whether it pos- sesses any true rasp, though it has the power of emitting a sound. From the analogy of the Orthoptera and Homoptera, I ex- pected to find the stridulating organs in the Coleoptera differ- ing according to sex ; but Landois, who has carefully examined several species, observed no such difference ; nor did Westring ; nor did Mr. G. R. Crotch in preparing the many specimens which he had the kindness to send me. Any difference in these organs, if slight, would, however, be difficult to detect, on account of their great variability. Thus, in the first pair of specimens of Vecrophorus humator and of Pelobius which I ex- amined, the rasp was considerably larger in the male than in the female; but not so with succeeding specimens. In Geo- trupes stercorarius the rasp appeared to me thicker, opaquer, and more prominent in three males than in the sams 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 living specimens, which he separated into two lots, according as they made a greater or lesser noise, when held in the same manner. He then examined all these spe- cimens, and found that the males were very nearly in the same proportion to the females in both the lots. Mr. F. Smith has kept alive numerous specimens of Monoynchus pseudacori (Cur- culionidz) and is convinced that both sexes stridulate, and ap- parently in an equal 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. (Tenebrionide) possess stridulating organs. I examined five males of H. gvbéus, and in all these there was a well-developed rasp, partially divided into two, on the dorsal surface of the terminal abdom- inal segment ; while 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 ZH. cribratostriatus the male has a similar rasp, excepting that it is not partially divided into two portions, and the female is completely destitute of this organ ; the male, in addition, has on the apical margins of the elytra, on each side of the suture, three or four short longitudinal ridges, which are crossed by extremely fine ribs, parallel to and resembling those on the abdominal rasp; whether these ridges serve as an independent 574 THE DESCENT OF MAN. {PART I. 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 »f the Lamellicorn genus Oryctes we have a nearly parallel case. In the females of O. gryphus and nasicornis the ribs on the rasp of the 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 O. senegalensis the difference between the sexes is more strongly marked. and this is best seen when tre proper abdominal segment is cleaned and viewed asatransparent object. Inthe female the whole surface is covered with little separate crests, bearing spines ; while in the male these crests in proceeding toward 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 1s pushed backward and forward. In the case of the Heliopathes and Oryctes there can hardly be a doubt that the males stridulate in order to call or to excite the females; but with most beetles the stridulat'on apparently serves both sexes as a mutual call. SHeetles stridu- late under various emotions, in the same manner as birds use their voices for many purposes besides singing to their mates. The great Chiasognathus stridulates in anger or defiance ; many species do the same from distress or fear, if held so that they cannot escape ; by striking the hollow stems of trees in the Canary Islands, Messrs. Wollaston and Crotch were able to discover the presence of beetles belonging to the genus Acalles by their stridulation. Lastly, the male Ateuchus stridulates to encourage the female in her work, and from distress wnen 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 cCevour a large beetle, would be frightened by so slight asound. The belief that the stridu- lation serves as asexual call is supported by the fact that death- ticks (Anobium tessellatum) are well known to answer each 79 M. P. de la Brulerie, as quoted in “Journal of Travel,” A. Murray, vol, i. 1868, Gs CHAP. XI.J BUTTERFLIES AND MOTHS 325 other’s ticking, and, as I have myself observed, a tapping noise artificially made. Mr. Doubleday also informs me that he has sometimes observed a female ticking,® and in an hour or two afterward he 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 en- abled 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. CHAPTER XI. INSECTS, continued.—ORDER, LEPIDOPTERA. (BUTTERFLIES AND MOTHS.) Courtship of butterflies—Battles—Ticking noise—Colors common to both sexes, or more brilliant in the males—Examples—Not due to tha direct action of the conditions of life—Colors adapted for protection _ —Colors of moths—Display—Perceptive powers of the Lepidoptera— Variability—Causes of the difference in color between the males and females—Mimicry, female butterflies more brilliantly colored than the males—Bright colors 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 color between the sexes of the same species, and between the distinct species of the same genus. Nearly the whole of the following chapter will be devoted to this subject ; but I will first make a few remarks on one or two other points. Several males may often be seen pursuing and crowding round the same female. Their courtship appears to be a prolonged affair, for I have frequently watched one or more males pirouet- ting round a female until I was tired, without seeing the end 80 According to Mr. Doubleday, “ the noise y : led B. xvii. s. 131. Oliver says (as quoted by is produced by the insect raising itself on its Kirby and Spence, ‘‘Introduct.” vol, u. py legs as high as it can, and then striking its thorax five or six times, in rapid succession, against the substance upon which it is sit- ting.” For references on this subject see Landois, ‘‘ Zeitschrift fiir Wissen. Zoolog.” 395) that the female of Pimelia striata pro duces a rather loud sound by striking her abdomen against any hard substance, “‘an@ that the male, obedient to this call, soon af tends her, and they pair.’ ; 326 THE DESCENT OF MAN. {PART It, 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 addresses. Although butterflies are weak and fragile creatures, they are pugnacious, and an Emperor butterfly 1 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 Avgeronia feronia makes a noise like that produced by a toothed wheel passing under a spring catch, and which can be heard at the distance of several yards: I noticed this sound at Rio de Janeiro, only when two of these butterflies were chasing each other in an irregular course, so that it is probably made during the courtship of the sexes.’ Some moths also 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 Aylophila prasinana, and which he believes to be produced, as in Cicada, by an elastic membrane, furnished with a muscle. He quotes, also, Guenée, 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 odor which is emitted by two species of Sphinx moths is peculiar to the males ;4 and in the higher classes we shall meet with many _ instances of the males alone being odoriferous. Everyone must have admired the extreme beauty of many 1 Apatura Iris: ‘‘The Entomologist’s production of the sound. For the case of Weekly Intelligence,” 1859, p. 139. Forthe ‘Thecophora, see ‘‘ Zoological Record,” 1869, Bornean Butterflies, see C. Coilingwood, ** Rambles of a Naturalist,’’ 1868, p. 183. 2 See my ‘* Journal of Researches,” 1845, p. 33» Mr. Doubleday has detected (“ Proc. Ent. Soc.’’ March 3, 1845, p. 123) a peculiar membranous sac at the base of the front wings, which is probably connected with the p. 401. For Mr. Buchanan White’s observa- tions, ‘‘The Scottish Naturalist,” July, 1872, Pp. 214. ; 3 **The Scottish Naturalist,” July, 1872, Pp. 213. : * “ Zoological Record,” 1869, p. 347+ cuapP. x1.J BUTTERFLIES AND MOTHS. 327 butterflies and of some moths; and it may be asked, are their colors and diversified patterns the result of the direct action of the physical conditions to which these insects have been ex- posed, without any benefit being thus derived ? Or have suc- cessive variations been accumulated and determined as a pro- tection, or for some unknown purpose, or that one sex may be attractive to the other? And, again, what is the meaning of the colors being widely different in the males and females of certain species, and alike in the two sexes of other species of the same genus? JBefore attempting to answer these questions a body of facts must be given. With our beautiful English butterflies, the admiral, peacock, and painted lady (Vanessz), as well as many others, the sexes are alike. ‘This is also the case with the magnificent Heli- conidz, and most of the Danaidz in the tropics. But in cer- tain other tropical groups, and in some of our English butter- flies, as the purple emperor, orange-tip, etc. (Apatura Iris and Anthocharis cardamines), the sexes differ either greatly or slightly in color. No language suffices to describe the splendor of the males of some tropical species. Even within the same genus we often find species presenting extraordinary differences between the sexes, while others have their sexes closely alike. Thus in the South American genus Epicalia, Mr. Bates, to whom I am indebted for- most of the following facts, and for looking over this whole discussion, informs me that he knows twelve species the two sexes of which haunt the same stations (and this is not aiways the case with butterflies), and which, therefore, cannot have been differently affected by external conditions.* In nine of these twelve species the males rank among 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 chey 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 colored in nearly the same manner. In the tenth species the female still retains the same general coloring, but the male resembles her, so that he is colored in a much less gaudy and contrasted § See also Mr. Bates’s paper in ‘‘ Proc. regard to Diadema, in ‘Transact. Ente Ent. Soc. of Philadelphia,” 1865, p. 206. molog. Soc. of London,” 1869, p. 278 es Also Mr. Wallace on the same subject, in 328 THE DESCENT OF MAN. [PART 1. manner than the males of the previous species. In the elev- enth and twelfth species the females depart from the usual type, for they are gayly decorated almost like the males, but in a somewhat less degree. Hence in these two latter species the bright colors of the males seem to have been transferred to the females ; while in the tenth species the male has either retained or recovered the plain colors of the female, as well as of the parent-form of the genus. ‘The sexes in these three cases have thus been rendered nearly alike, though in an opposite man- ner. In the allied genus Eubagis, both sexes of some of the species are plain-colored and nearly alike; while with the greater number the males are decorated with beautiful metallic tints in a diversified manner, and differ much from their fe- males. The females throughout the genus retain the same general style of coloring, so that they resemble one another much more closely than they resemble their own males. In the genus Papilio, all the species of the Aineas group are remarkable for their conspicuous and strongly contrasted colors, and they illustrate the frequent tendency to gradation in the amount of difference between the sexes. In a few species, for instance in P. ascanius, the males and females are alike; in others the males are either a little brighter or very much more superb than the females. The genus Junonia, allied to our Vanessz, offers a nearly parallel case, for although the sexes of most of the species resemble each other, and are destitute of rich colors, yet in certain species, as in /. enone, the male is rather more bright-colored than the female, and in a few (for instance /. andremiaja) the male is so differ- ent 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 Ameri- can Thecle, in which both sexes are nearly alike and wonder- fully splendid; in another species the male is colored ina similarly gorgeous manner, while the whole upper surface of the female is of a dull uniform brown. Our common little English blue butterflies of the genus Lyczena illustrate the various differences in color between the sexes almost as well, though not in so striking a manner, as the above exotic genera. In Lycena agestis both sexes have wings of a brown color, bordered with small ocellated orange spots, and are thus ~ alike. In Z. wgon the wings of the male are of a fine blue, bordered with black; while those of the female are brown, — CHAP, XI.) BUTTERFLIES AND MOTHS. 329 with a similar border, closely resembling the wings of Z. agestts. Lastly, in Z. arton both sexes are of a blue color 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 from the usual type of coloring of the group to which the species be- longs. Hence in most groups the females of the seve.al species resemble each other much more closely than do the males. In some cases, however, to which I shall hereafter allude, the fe- males are colored more splendidly than the males. In the sec- ond 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 color 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 ap- pears due either to the male having transferred his colors to the female, or to the male having retained, or perhaps recovered, the primordial colors of the group. It also deserves notice that in those groups in which the sexes differ the females usually somewhat resemble the males, so that when the males are beautiful to an extraordinary degree, the females almost in- variably exhibit some degree of beauty. From the many cases of gradation in the amount of difference between the sexes, and from the prevalence of the same general type of coloration throughout the whole of the same group, we may conclude that the causes have generally been the same which have determined the brilliant coloring 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 colors to the great heat and moisture of these zones; but Mr. Bates ® has shown, by the comparison of various closely allied groups of insects from the temperate and tropical regions, that this view cannot be maintained; and the evidence becomes conclusive when brilliantly colored males and plain-colored females of the same species inhabit the same district, feed on the same food, and follow exactly the same habits of life. Even when the sexes resemble each other, we can hardly believe that their brilliant $ “The Naturalist on the Amazons,” vol, i. 1863, P. 1Q- 330 THE DESCENT OF MAN. {PART 11 and beautifully arranged colors are the purposeless result of the nature of the tissues and of the action of the surrounding con- ditions. With animals of all kinds, whenever color 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 be- tween the sexes. With many species of butterflies the upper surfaces of the wings are obscure; and this in all probability leads to their escaping observation and danger. But butter- flies would be particularly liable to be attacked by their ene- mies when at rest; and most kinds while resting raise their wings vertically over their backs, so that the lower surface alone is exposed to view. Hence it is this side which is often colored so as to imitate the objects on which these insects commonly rest. Dr. Réssler, I believe, first noticed the sim- ilarity of the closed wings of certain Vanessze and other butter- flies 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 (Kallima), which disappears like magic when it settles on a bush ; for it hides its head and antennze between its closed wings, which, in form, color, and veining, cannot be dis- tinguished from a withered leaf with its footstalk. In some other cases the lower surfaces of the wings are brilliantly colored, and yet are protective; thus in Zhecla rubi the wings when closed are of an emerald green, and resemble the young leaves of the bramble, on which in spring this butterfly may often be seen seated. It is also remarkable that in very many species, in which the sexes differ greatly in color 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 upper and under sides of many butterflies no doubt serve to conceal them, yet we can- not extend this view to the brilliant and conspicuous colors on the upper surface of such species as our admiral and peacock Vanessz, our white cabbage-butterflies (Pieris), or the great swallow-tail Papilio which haunts the open fens—for these but- terflies 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 * See a very interesting article in the Science Gossip” for September, 1867, page “Westminster Review” for July, 1867, 196. [ page to. A wood-cut of the Kallima 1s & Mr. G. Fraser, in ‘‘Nature,” April, given by Mr. Wallace in ** Hardwicke’s 1871, p. 489. CHAP, XI} BUTTERFLIES AND MOTHS. 331 yellow, while the female is much paler; and in the orange-tip Anthocharis cardamines) the males alone have their wings tipped with bright orange. Both the males and females in these cases are conspicuous, and it is not credible that their difference in color should stand in any relation to ordinary protection. Prof. Weismann remarks ® that the female of one of the Lycanz expands her brown wings when she settles on the ground, and is then almost invisible; the male, on the other hand, as if aware of the danger incurred from the bright blue of the upper surface of his wings, rests with them closed; and this shows that the blue color cannot be in any way protective. Never- theless, it is probable that conspicuous colors are indirectly beneficial to many species, as a warning that they are unpal- atable. 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. genutia) probably show us the primordial colors of the parent-species of the genus ; for bothsexes of four or five widely distributed species are colored in nearly the same man- mer. As in several previous cases, we may here infer that it is the males of Anth. cardamines and genutia which have departed from the usual type of the genus. In the Anzh. sara from Cali- fornia, the orange-tips to the wings have been partially devel- oped in the female; but they are paler than in the mals, and slightly different in some other respects. In an allied Iadian form, the /phias glaucippe, the orange-tips are fully developed in both sexes. In this Iphias, as pointed out to me by Mr. A. Butler, the under surface of the wings marvellously resembles a pale- colored leaf; and in our English orange-tip, the vader surface resembles the flower-head of the wild parsley, on which the butterfly often rests at night.!°. The same reason which compels us to believe that the lower surfaces have here been col- ored for the sake of protection, leads us to deny that the wings have been tipped with bright orange for the same purpose, és- ' pecially when this character is confined to the males. Most Moths rest motionless during the whole or greater ® “Einfluss der Isolirung auf die Art- T. W. Wood, “The Student,” Sept >48, bildung,” 1872, p. 58. p. 81. 19 See the interesting observations by Mr. 332 THE DESCENT OF MAN, [PART IL part of the day with their wings depressed, and the whole upper surface is often shaded and colored in an admirable manner, as Mr. Wallace has remarked, for escaping detection. The front-wings of the Bombycidz and Noctuidz," when at rest, generally overlap and conceal the hind-wings, so that the latter might be brightly colored without much risk; and they are in fact often thus colored. During flight, moths would often be able to escape from their enemies ; neverthe- less, as the hind-wings are then fully exposed to view, their bright colors must generally have been acquired at some little risk. But the following fact shows how cautious we ought to be in drawing conclusions on this head. ‘The common Yellow Under-wings (Triphzena) often fly about during the day or early evening, and are then conspicuous from the color of their hind-wings. It would naturally be thought that this woula 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 colored and fragile surfaces, instead of at the body. For instance, Mr. Weir turned into his aviary a vig- crous specimen of Zrishena pronuba, which was instantly pursued by a robin; but the bird’s attention being caught by the colored 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 7. fiméria,; but the large size of this moth probably interfered with its capture.” We are thus reminded of a statement made by Mr. Wallace,® namely, that in the Brazilian forests and Malayan 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 wings, as if they had been seized by birds, from which they had escaped; if the wings had been much smaller in proportion to the body, it seems probable that the insect would more frequently have been struck or pierced in a vital part, and thus the increased expanse of the wings may have been indirectly beneficial.’’ Display.—The bright colors of many butterflies and of some moths are specially arranged for display, so that they may be readily seen. During the night colors are not visible, and there can be no doubt that the nocturnal moths, taken as 43 Mr. Wallace in ‘* Rn ee Science paper in ‘‘ Transact. Ent. Society,” 1869, p. Gossip. ” Sept. 1867, p. 19 23. , 2 See also, on this A ae Mr. Weir’s 23 ‘* Westminster Rev.’’ July, 1867, p. 16. CHAP. X1.] BUTTERFLIES AND MOTHS. 333 a body, are much less gayly decorated than butterflies, all of which are diurnal in their habits. But the moths of certain families, such as the Zygzenidz, several Sphingide, Uraniide, some Arctiidz and Saturniide, fly about during the day or early evening, and many of these are extremely beautiful, be- ing far brighter colored than the strictly nocturnai kinds. A few exceptional cases, however, of bright-colored nocturnal} 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 while basking in the sunshine often alternately raise and depress them, thus exposing both surfaces to full view ; and although the lower surface is often colored in an obscure man- ner as a protection, yet in many species it is as highly dec- orated as the upper surface, and sometimes in a very different manner. In some tropical species the lower surface is even more brilliantly colored than the upper.’ In the English fritil’aries (Axgynnis) the lower surface alone is ornamented with shining silver. Nevertheless, as a general rule, the upper surface, which is probably more fully exposed, is colored more brightly and diversely than the lower; hence the lower sur- face generally affords to entomologists the more useful character for detecting the affinities of the various species. Fritz Miiller informs me that three species of Castnia are found near his house in South Brazil: of two of them the hind-wings are ob- scure, 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 rests. Other such cases could be added. If we now turn to the enormous group of moths which, as I hear from Mr. Stainton, do not habitually expose the under surface of their wings to full view, we find this side very rarely colored with a brightness greater than, or even equal to, that of the upper side. Some exceptions to the rule, either real or apparent, must be noticed, as the case of Hypopyra’® Mr. Trimen inform me that in Guenée’s great work three moths 14 For instance, Lithosia; but Prof, West- wood (‘‘ Modern Class. of Insects,” vol. ii. Pp. 390) seems surprised at this case. On and lower surfaces of the wings of several species of Papilio may be seen in the beau- tiful plates to Mr. Wallace’s ‘* Memoir on the relative colors of diurnal and nocturnal Lepidoptera, see ibid. pp. 333 and 392; also Harris, ‘‘Treatise on the Insects of New aca 1842, p. 315. Such differences between the upper the Papilionidz of the Malayan Region,” in & Tranmagt Linn. Soc.” vol. xxv. part. i. 1865. 48 See Mr. Wormald on this moth* “* Prote Ent. Soc.” March = R48. ; an ag 334 THE DESCENT OF MAN, {PART IL are figured, in which the under surface is much the more brill- iant. For instance, in the Australian Gastrophora the upper surface of the fore-wing is pale grayish-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-yellow, and this by bluish-white. But the habits of these three moths are unknown, so that no explanation can be given of their unusual style of coloring. Mr. Trimen also in- forms me that the lower surface of the wings in certain other Geometre ! and quadrifid Noctuz are either more variegated or more brightly colored 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 consid- erable 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 sur- face in certain moths is not so anomalous as it at first appears. The Saturniidze 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 if for display, which is more characteristic of diurnal than of nocturnal Lepidoptera.’’ . It is a singular fact that no British moths which are brill- iantly colored, and, as far as I can discover, hardly any for- eign species, differ much in color according to sex ; though this is the case with many brilliant butterflies. The male, however, of one American moth, the Saturnia Jo, is described as having its fore-wings deep yellow, curiously marked with purplish-red spots; while the wings of the female are purple- brown, marked with gray lines. The British moths which differ sexually in color 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, 17 See also an account of the S. American cabinet that the males are darker than the genus Erateina (one of the Geometra) in females in the Lastocampa guercus, Odo- “Transact. Ent, Soc.” new series, vol. v. pl. zestis potatoria, Hypogymna dispar, Da- xv. and xvi. sychira pudibunda, and Cycenia mendica. 48 “Proc. Ent. Soc. of London,” July 6, In this latter species the difference in color 1868, p. xxvii. between the two sexes is strongly marked ; 19 Harris, “Treatise,” etc., edited by and Mr. Wallace informs me that we here Flint, 1862, p. 395- Lave, as he believes, an instance of pro- %0 For instance, I observe in my son’s tective mimicry confined to one sex, as BUTTERFLIES AND MOTHS. 335 CHAP. XLJ 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 (Hefialus humuli) the difference is more strongly marked ; the males being white, and the females yellow with darker markings. It is probable that in these cases the males are thus rendered more conspicuous, and more easily seen by the females while flying about in the dusk. From the several foregoing facts it is impossible to admit that the brilliant colors of butterflies, and of some few moths, have commonly been acquired for the sake of protection. We have seen that their colors and elegant patterns are arranged and exhibited as if for display. Hence I am led to believe that the females prefer or are most excited by the more brilliant males ; for on any other supposition the males would, as far as we can see, be ornamented to no purpose. We know that ants and certain Lamellicorn beetles are capable of feeling an attach- ment for each other, and that ants recognize their fellows after an interval of several months. Hence there is no abstract im- probability in the Lepidoptera, which probably stand nearly or quite as high in thescale as these insects, having sufficient mental capacity to admire bright colors. They certainly dis- cover flowers by color. The Humming-bird Sphinx may often be seen to swoop down from a distance on a bunch of flow- ers in the midst of green foliage ; and I have been assured, by two persons abroad, that these moths repeatedly visit flowers painted on the walls of a room, and vainly endeavor to insert their proboscis into them. Fritz Miiller informs me that sev- eral kinds of butterflies in South Brazil show an unmistakable preference for certain colors over others: he observed that they very often visited the brilliant red flowers of five or six genera of plants, but never the white or yellow flowering species of the same and other genera, growing in the same garden; and I have received other accounts to the same effect. As I hear from Mr. Doubleday, the common white butterfly often flies hereafter be more fully explained. The — 21 It is remarkable that in the Shetland white female of the Cycnia resembles the very common Sfzlosoma menthrasti, both sexes of which are white ; and Mr. Stainton observed that this latter moth was rejected with utter disgust by a whole brood of young turkeys, which were fond of eating other moths ; so that if the Cycnia was commonly mistaken by British birds for the Spilosoma, it would escape being devoured, and its white as color would thus be highly Islands the male of this moth, instead of differing widely from the female, frequently resembles her closely in color (see Mr. Mac- Lachlan, ‘‘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 islands, the whiteness of the males would not be needed to render them visible to the females in the twilight night. 336 THE DESCENT OF MAN. (PART 11 down to a bit of paper on the ground, no doubt mistaking it ror one of its own species. Mr. Collingwood,” in speaking of the difficulty in collecting certain butterflies in the Malay Archipelago, states that ‘‘a dead specimen pinned upon a conspicuous twig will often arrest an insect of the same species in its headlong flight, and bring it down within easy reach of the net, especially if it be of the opposite sex.”’ The courtship of butterflies is, as before remarked, a pro- longed affair. The males sometimes fight together in rivairy ; and many may be seen pursuing or crowding round the same female. Unless, then, the females prefer one male to another, the pairing must be left to mere chance, and this does not appear probable. If, on the other hand, the females habitually, or even occasionally, prefer the more beautiful males, the colors of the latter will have been rendered brighter by de- grees, and will have been transmitted to both sexes or to one sex, according to the law of inheritance which has prevailed. The process of sexual selection will have been much facilitated, if the conclusion can be trusted, arrived at from various kinds of evidence in the supplement to the ninth chapter ; namely, that the males of many Lepidoptera, at least in the imago state, greatly exceed the females in number. Some facts, however, are opposed to the belief that female butterflies prefer the more beautiful males; thus, as I have been assured by several collectors, fresh females may frequently be seen paired with battered, faded, or dingy males ; but this is a circumstance which could hardly fail often to follow from the males emerging from their cocoons earlier than the females, With moths of the family of the Bombycidz the sexes pair immediately after assuming the imago state; for they cannot feed, owing to the rudimentary condition of their mouths. The females, as several entomologists have remarked to me, lie in an almost torpid state, and appear not to evince the least choice in regard to their partners. This is the case with the common silk-moth (B. mor), as I have been told by some continental and English breeders. Dr. Wallace, who has had great experience in breeding Bombyx cynthia, is convinced that the females evince no choice or preference. He has kept above 300 of these moths together, and has often found the most vigorous females mated with stunted males. The reverse appears to occur seldom ; for, as he believes, the more vigorous males pass over the weakly females, and are attracted by those $3 «* Rambles of a Naturalist in the Chinese Seas,” 2868, p. 3982, CHAP. XI.) BUTTERFLIES AND MOTHS, 337 endowed with most vitality. Nevertheless, the Bombycide, though obscurely colored, are often beautiful to our eyes from their elegant and mottled shades. I have as yet only referred to the species in which the males are brighter colored than the females, and I have attributed their beauty to the females for many generations having chosen and paired with the more attractive males. But converse cases occur, though rarely, in which the females are more brill- iant than the males; and here, as I believe, the males have selected the more beautiful females, and have thus slowly added to their beauty. Wedo not know why in various classes of animals the males of some few species have selected the more beautiful females instead of having gladly accepted any female, as seems to be the general rule in the animal kingdom ; but if, contrary to what generally occurs with the Lepidoptera, the females were much more numerous than the males, the latter would be likely to pick out the more beautiful females. Mr. Butler showed me several species of Callidryas in the British Museum, in some of which the females equalled, and in others greatly surpassed, the males in beauty ; for the females alone have the borders of their wings suffused with crimson and orange, and spotted with black. The plainer males of these species closely resemble each other, showing that here the females have been modified ; whereas in those cases where the males are the more ornate, it is these which have been modified, the females remaining closely alike. In England we have some analogous cases, though not so marked. The females alone of two species of Thecla have a bright-purple or orange patch on their fore-wings. In Hip- parchia the sexes do not differ much ; but it is the female of HT. janira which has a conspicuous light-brown patch on her wings ; and the females of some of the other species are brighter colored than their males. Again, the females of Colias edusa and hyale have ‘‘ orange or yellow spots on the black mar- ginal border, represented in the males only by thin streaks ;’’ and in Pieris it is the females which ‘‘ are ornamented with black ‘‘spots on the fore-wings, and these are only partially present in the males.’’ Now, the males of many butterflies are known to support the females during their marriage flight ; but in the species just named it is the females which support the males ; so that the part which the two sexes play is reversed, as is their relative beauty. Throughout the animal kingdom the males commonly take the more active share in wooing, and (O)—-Vol. 8 THE DESCENT OF MAN, {PART It, 338 their beauty seems to have been increased by the females hav- ing accepted the more attractive individuals; but with these butterflies the females take the more active part in the final marriage ceremony, so that we may suppose that they likewise do so in the wooing ; and in this case we can understand how it is that they have been rendered the more beautiful. Mr. Meldola, from whom the foregoing statements have been taken, says in conclusion: ‘* Though I am not convinced of the ac- tion of sexual selection in producing the colors of insects, it cannot be denied that these facts are strikingly corroborative of Mr. Darwin’s views.’’ * As sexual selection primarily depends on variability, a few words must be added on this subject. In respect to color there is no difficulty, for any number of highly variable Lepidop- tera could be named. One good instance will suffice. Mr. Bates showed me a wholeseries of specimens of Pafpzlio sesostris and P. childrene ; in the latter the males varied much in the extent of the beautifully enamelled green patch on the fore- wings, and in the size of the white mark, and of the splendid crimson stripe on the hind-wings; so that there was a great contrast among the males between the most and the least gaudy. The male of Papilio sesostris is much less beautiful than of P. childrene ; and it likewise varies a little in the size of the green patch on the fore-wings, and in the occasional appearance of the small crimson stripe on the hind-wings, borrowed, as it would seem, from its own female; for the females of this and of many other species in the Aineas group possess this crim- son stripe. Hence, between the brightest specimens of P. se- sostris and the dullest of P. chitldreng, there was but a small interval ; and it was evident that, as far as mere variability is concerned, there would be no difficulty in permanently in- creasing the beauty of either species by means of selection. The variability is here almost confined to the male sex ; but Mr. Wallace and Mr. Bates have shown that the females of some species are extremely variable, the males being nearly constant. In a future chapter I shall have occasion to show 33 “Nature,” April 27, 1871, p. 508. Mr. Meldola quotes Donzel, in *‘ Soc. Ent. de France,” 1837, p. 77, on the flight of butter- flies while pairing. See also Mr. G. Fraser, in “‘ Nature,” April 20, 1871, p. 489, on the sexual differences of several British butter- es. _ 34 Wallace on the Papilionide of the Malayan Region, in “‘ Transact. Linn. Soc.” ~ vol. xxv. 1865, pp. 8, 36. A striking case of a rare variety, strictly intermediate be- tween two other well-marked female varie- ties, is given by Mr. Wallace. Seealso Mr. Bates, in ‘Proc. Entomolog, Soc..” Now, 19, 1866, p. xi, Y: CHAP. Xt] BUTTERFLIES AND MOTHS. 339 that the beautiful eye-like spots, or ocelli, found on the wings of many Lepidoptera, are eminently variable. I may here add that these ocelli offer a difficulty on the theory of sexual selec- tion ; for though appearing to us so ornamental, they are never present in one sex and absent in the other, nor do they ever differ much in the two sexes.” ‘This fact is at present inexpli- cable ; but if it should hereafter be found that the formation of an ocellus is due to some change in the tissues of the wings, for instance, occurring at a very early period of development, we might expect, from what we know of the laws of inheritance, that it would be transmitted to both sexes, though arising and perfected in one sex alone. On the whole, although many serious objectietXs may be urged, it seems probable that most of the brilliantly colored species of Lepidoptera owe their colors to sexual selection, ex- cepting in certain cases, presently to be mentioned, in which conspicuous colors have been gained through mimicry as a protection. From the ardor of the male throughout the ani- mal kingdom, he is generally willing to accept any female ; and it is the female which usually exerts a choice. Hence, if sexual selection has been efficient with the Lepidoptera, the male, when the sexes differ, ought to be the more brilliantly colored, and this undoubtedly is the case. When both sexes are brilliantly colored and resemble each other, the characters acquired by the males appear to have been transmitted to both. Weare led to this conclusion by cases, even within the same genus, of gradation from an extraordinary amount of difference to identity in color between the two sexes. But it may be asked whether the differences in color he- 4ween the sexes may not be accounted for by other means be- sides sexual selection. Thusthe males and females of the same species of butterfly are in several cases known” to inhabit different stations, the former commonly basking in the sup shine, the latter haunting gloomy forests. It is therefore pos- sible that different conditions of life may have acted directly on the two sexes ; but this is not probable,” as in the adult state they are exposed to different conditions during a very short period ; and the larvee of both are exposed to the same con- ditions. Mr. Wallace believes that the difference between the %# Mr. Bates was so kind as to lay this subject before the Entomological Society, and [ have received answers to this effect from several entomologists. 39 H. W. Bates, “ The Naturalist in the fanazons,” vol. ii. 1863, p. 228. A, R. Wal- lace, in ‘“‘ Transact. Linn, Soc.” vol. xxWe 1865, p. 10. 37 bn this whole subject see ‘‘ The Variae tion of Animals and Plants under Domes® cation,” 1868, vol, ii. chap. xXxtil. v¢ y - CHAP. x11] FISHES, 368 Prof. 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 Chromids, as Prof. Agassiz likewise informs me, sexual differences in color may be observed, ‘‘ whether they lay their eggs in the water among aquatic plants or deposit them in holes, leaving them to come out without further care, or build shallow nests in the river mud, over which they sit, as our Pomotis does. It ought also to be observed that these sitters are among the brightest species in their respective families; for instance, Hygrogonus is bright green, with large black ocelli, encircled with the most brilliant red.’’ Whether with all the species of Chromids it is the male alone which sits on the eggs is not known. It is, however, manifest that the fact of the eggs being protected or unprotected by the parents has had little or no influence on the differences in color between the sexes. It is further manifest, in all the cases in which the males take ex- clusive charge of the nests and young, that the destruction of the brighter colored males would be far more influential on the character of the race than the destruction of the brighter colored females ; fer 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 colored than the females. In most of the Lophobranchii (Pipe-fish, Hippocampi, etc.) the males have either marsupial sacks or hemispherical depres- sions on the abdomen, in which the ova laid by the female are hatched. The males also show great attachment to their young. The sexes do not commonly differ much in color; but Dr. Giinther believes 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 colored and spotted than the male, and she alone has a marsupial sack and hatches the eggs; so that the female of Turner, in “ Journal of Anatomy and Phys,” 40 Dr. Giinther, since publishing an ac- Novy. 1, 1866, p. 78. Dr. Giinther has fike- count of this species in *‘ The Fishes of Zan- wise described other cases. zibar,” by Col. Playfair, 1866, p. 137, has re 8° Yarrell, ‘* Hist. of British Fishes,” vol. examined the specimens, and has given me ti, 1836, pp. 329, 338. the above information. 266 THE DESCENT OF MAN, {part me Solenostoma differs from all the other Lophobranchii in this iatter respect, and from almost all other fishes, in being more brightly colored than the male. It is improbable that this re- markable double inversion of character in the female should be an accidental coincidence. As the males of several fishes, which take exclusive charge of the eggs and young, are more brightly colored 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 colors of that sex, which is the more important of the two fcr the welfare of the off- spring, must be in some manner protective. But from the large number of fishes of which the males are either perma- nently or periodically brighter than the females, but whose life is not at all more important for the welfare of the species than that of the female, this view can hardly be maintained. When we treat of birds we shall meet with analogous cases, where there has been a complete inversion of the usual attributes of the two sexes, and we shall then give what appears to be tke probable explanation, namely, that the males have selected the more attractive females, instead of the latter having selected, in accordance with the usual rule throughout the animal kingdom, the more attractive males. On the whole, we may conclude that, with most fishes in which the sexes differ in color or in other ornamental charac- ters; the males originally varied, with their variations trans- mitted to the same sex, and accumulated through sexual selec- tion 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 colored alike for the sake of protection; but in no instance does it appear that the female alone has had her colors or other characters specially modified for this latter pur- ose. : 2 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. Dufossé, 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 pharyn- geal bones—by the vibration of certain muscles attached to the swim-bladder, which serves as a resounding board—and by © i the vibration of the intrinsic 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 ine CHAP, XII.) AMPHIBIANS. 307 teresting 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.“4 The drum- ming of the Umbrinas in the European seas is said to be audi- ble from a depth of twenty fathoms; and the fishermen of Rochelle 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 Vertebrata, as with so many in- sects and spiders, sound-producing instruments have, at least in some cases, been developed through sexual selection, as a means for bringing the sexes together. AMPHIBIANS. Urodela.—I will begin with the tailed amphibians. The sexes of salamanders or newts often differ much both in color Pic. ae cristatus (half natural size, from Bell’s ‘ British Reptiles’’), * . r gure, male during the breeding season: lower figure, female. Vere and structure. In some species prehensile claws are dey , veloped on the fore-legs of the males during the. breeding season :, wid 41 « : : nk get a prs a 1858, the Dutch translation of this work (vol. ,ii + 353- : » 1856, p. 5 m. liv. 36), ie i , the: 1862, p. 393. The noise made by the Ury- sduindsimade by Ache eee ve thes brinas ( Sciena aguila), is said by some 42. The Rev;Ci'Kinesley, in “Nature.” authors to be more like that of a flute or ‘or- ‘ee ee : > May, 18 ’ % gan than drumming. Dr. Zoufeveen, in ee "i - : a a i ; 368 THE DESCENT OF MAN. [PART 1 at this season in the male 7yzton palmipes the hind feet are pro- vided with a swimming-web, which is almost completely ab- sorbed during the winter ; so that their feet then resemble those of the female.“® This structure no doubt aids the male in his eager search and pursuit of the female. While courting her he rapidly vibrates the end of his tail. With our common newts ( Triton punctatus and cristatus) a deep, much indented crest is developed along the back and tail of the male during the breeding season, which disappears during the winter. Mr. St. George Mivart informs me that it is not furnished with muscles, and therefore cannot be used for locomotion. As during the season of courtship it becomes edged with bright colors, there can hardly be a doubt that it is a masculine ornament. In many species the body presents strorzly contrasted, though lurid tints, and these become more vivid during the breeding season. The male, for instance, of our common little newt (Triton punctatus) is ‘‘ brownish - gray above, passing into yellow beneath, which in the spring becomes a rich bright orange, marked everywhere with round dark spots.’’ The edge of the crest also is then tipped with bright red or violet. The female is usually of a yellowish-brown color with scattered brown dots, and the lower surface is often quite plain.“4 The young are obscurely tinted. The ova are fertilized during the act of deposition, and are not subsequently tended by either parent. We may therefore conclude that the males have acquired their strongly marked colors and ornamental append- ages through sexual selection ; these being transmitted either to the male offspring alone, or to both sexes. Anura or Batrachia.—With many frogs and toads the colors evidently serve as a protection, such as the bright green tints of tree frogs and the obscure mottled shades of :nany terrestrial species. The most conspicuously colored toad which I ever saw, the Phryniscus nigricans,® hat the wnole upper surface of the body as black as ink, with the soics of the feet and parts of the abdomen spotted with the brigiitest vermilion. It crawled about the bare sandy or open grassy plains of La Plata under a scorching sun, and could not fail to catch the eye of every passing creature. These colors are probably beneficial by making this animal known to all birds of prey as a nauseous mouthful. 43 Bell, ‘‘ History of British Reptiles,” 8 “ Zoology of the Voyage of the ‘ Bear 2d edit. 1849, pp. 156-159. gle,’” 1843. Bell, ibid, p, 49, 4 Tbid., Pp- 146, 151, 7 CHAP. XII] AMPHIBIANS. 360 In Nicaragua there is a little frog ‘‘ dressed in a bright livery of red and blue’’ which does not conceal itself like most other species, but hops about during the daytime, and Mr. Belt says “6 that as soon as he saw its happy sense of security, he felt sure that it was uneatable. After several trials he succeeded in tempting a young duck to snatch up a young one, but it was instantly rejected ; and the duck ‘‘ went about jerking its head, as if trying to throw off some unpleasant taste.’’ With respect to sexual differences of color, Dr. Giinther does not know of any striking instance either with frogs or toads; yet he can often distinguish the male from the female by the tints of the former being a little more intense. Nor does he know of any striking difference in external structure between the sexes, excepting the prominences which become developed during the breeding season on the front legs of the male, by which he is enabled to hold the female.“ It is sur- prising that these animals have not acquired more strongly marked sexual characters ; for, though cold-blooded, their pas- sions are strong. Dr. Giinther informs me that he has several times found an unfortunate female toad dead and smothered from having been so closely embraced by three or four males. Frogs have been observed by Prof. Hoffman in Giessen fizhting all day long during the breeding season, and with so much violence, that one had its body ripped open. Frogs and toads offer one interesting sexual difference, namely, in the musical powers possessed by the males; but to speak of music, when applied to the discordant and overwhelm- ing sounds emitted by male bull-frogs and some other spe- cies, seems, according to our taste, a singularly inappropriate expression. Nevertheless, certain frogs sing in a decidedly pleasing manner. Near Rio Janeiro I used often to sit in the evening to listen to a number of little Hyle, perched on blades of grass close to the water, which sent forth sweet chirping * notesin harmony. ‘The various sounds are emitted chiefly by the males during the breeding season, as in the case of the croaking of our common frog.® In accordance with this fact the vocal organs of the males are more highly developed than those of the females. In some genera the males alone are pro- vided with sacs which open into the larynx.” For instance, in 46 “The Naturalist in Nicaragua,” 1874, gers, which perhaps subserve the same end . 32I. , as the above-mentioned prominences. 47 I'he male alone of the Bujo stkinzmen- *8 Bell, ‘* History of British Reptiles,” sés (Dr. Anderson, ‘‘ Proc, Zoolog. Soc.” 1849, p. 93- 1871, p. 204) has two plate-like callosities on *9 J. Bishop, in ** Todd’s Cyclop. of Ana the thorax and certain rugosities on the fin- and Phys.” vol. iv. p. 1503. 379 THE DESCENT OF MAN. [PART IL the edible frog (Rana esculenta) ‘‘ the sacs are peculiar to the males, and become, when filled with air in the act of croaking, large globular bladders, standing out one on each side of the head, near the corners of the mouth.’’ ‘The croak of the male is thus rendered exceedingly powerful, while that of the female is only a slight groaning noise.” In the several genera of the family the vocal organs differ considerably in structure, and their development in all cases may be attributed to sexual selection. REPTILES. Chelonia.—Tortoises and turtles do not offer well-marked sexual differences. In some species the tail of the male is longer than that of the female. In some the plastron or lower surface of the shell of the male is slightly concave in relation to the back of the female. ‘The male of the mud-turtle of the United States (Chrysemys picta) has claws on its front feet twice as long as those of the female; and these are used when the sexes unite.*! With the huge tortoise of the Galapagos Islands ( Testudo nigra) the males are said to grow to a larger size than the females: during the pairing season, and at no other time, the male utters a hoarse bellowing noise, which can be heard at the distance of more than a hundred yards ; the female, on the other hand, never uses her voice.™ With the Zestudo elegans of India, it is said ‘‘ that the com- bats of the males may be heard at some distance, from the noise they produce in butting against each other.’’ Crocodilia.—The sexes apparently do not differ in color ; nor do I know that the males fight together, though this is probable, for some kinds make a prodigious display before the females. Bartram *! describes the male alligator as striving to win the female by splashing and roaring in the midst of a lagoon, ‘‘swollen to an extent ready to burst, with its head and tail lifted up, he spins or twirls round on the surface of the water, like an Indian chief rehearsing his feats of war.’ During the season of love a musky odor is emitted by the submaxillary glands of the crocodile, and pervades their haunts.® < Bell, ibid. p. 112-1: 63 Dr. esos ‘Reptiles of British In- 1 Mr. C, he ee, -¢ Ps American dia,’ ? "3864, P N: tie Dec.. 1869, p. RS Be sg eens Carolina,” etc., 1791, 52 See my ‘ Journal of peel dur- p. oe ing the Voyage of the ‘ Beagle,’”’ 1845, p. 55 Oy wos “* Anatomy of Vertebrates.” vob a4. i, 1806, De O45, ~ CHAP, X11.j REPTILES. 371 Ophidia.—Dr. Giinther informs me that the males are always smaller than the females, and generally have longer and slen- derer tails; but he knows of no other difference in external structure. In regard to color, he can almost always dis- tinguish the male from the female by his more strongly pro- nounced tints ; thus the black zigzag band on the back of the male English viper is more distinctly defined than in the female. The difference is much plainer in the rattlesnakes of North America, the male of which, as the keeper in the Zoological Gardens showed me, can at once be distinguished from the female by having more lurid yellow about its whole body. In South Africa the Bucephalus capensis presents an analogous difference, for the female ‘‘is never so fully variegated with yellow on the sides as the male.’’ ® The male of the Indian Dipsas cynodon, on the other hand, is blackish-brown, with the belly partly black, while the female is reddish or yellowish- olive, with the belly either uniform yellowish or marbled with black. In the Zragops dispar of the same country, the male is bright green, and the female bronze-colored.** No doubt the colors of some snakes are protective, as shown by the green tints of tree-snakes, and the various mottled shades of the species which live in sandy places; but it is doubtful whether the colors of many kinds, for instance of the common English snake and viper, serve to conceal them; and this is still more doubtful with the many foreign species which are colored with extreme elegance. ‘The colors of certain species are very differ- ent in the adult and young states.*® During the breeding season the anal scent-glands of snakes are in active function ;* and so it is with the same glands in lizards, and, as we have seen, with the submaxillary glands of crocodiles. As the males of most animals search for the females, these odoriferous glands probably serve to excite or charm ‘ns ‘emale, rather than to guide her to the spot where the male may be found. Male snakes, though appearing so slug- gish, are amorous ; for many have been observed crowding round the same female, and even round her dead body. ‘They are not known to fight together from rivalry. Their intellect- ual powers are higher than might have been anticipated. In the Zoological Gardens they soon learn not to strike at the iron bar with which their cages are cleaned; and Dr. Keen of 66 Sir Andrew nan Fg of S. $8 Dr. Stoliczka, ‘* Journal of Asiatic Soc. pipes: Reptilia,” 1849, p of Bengal,” vol. xxxix. 1870, pp. 205, 211. r. A. Giinther, “ Retiles of British 59 Owen, “‘ Anatomy of Vertebrates,’ vol, India,” Re™ ““c. 1864, pp. 304, 308. i, 1866, p, Gre. 392 THE DESCENT OF MAN. {PART 11, Philadelphia informs me that some snakes which he kept, learned after four or five times to avoid a noose with which they were at first easily caught. An excellent observer in Cey- lon, Mr. E. Layard, saw a cobra thrust its head through a narrow hole and swallow a toad. ‘‘ With this encumbrance he could not withdraw himself; finding this, he reluctantly dis- gorged the precious morsel, which began to move off ; this was too much for snake philosophy to bear, and the toad was again seized, and again was the snake, after violent efforts to escape, compelled to part with its prey. This time, however, a lesson had been learned, and the toad was seized by one leg, with- drawn, and then swallowed in triumph.”’ The keeper in the Zoological Gardens is positive that certain snakes, for instance Crotalus and Python, distinguish him from all other persons. Cobras kept together in the same cage apparently feel some attachment toward each other. It does not, however, follow, because snakes have some reasoning power, strong passions, and mutual affection, that they should likewise be endowed with sufficient taste to admire brilliant colors in their partners, so as to lead to the adornment of the species through sexual selection. Nevertheless; it is difficult to account in any other manner for the extreme beauty of certain species; for instance, of the coral-snakes of South America, which are of a rich red with black and yellow transverse bands. I well remember how much surprise I felt at the beauty of the first coral-snake which I saw gliding across a path in Brazil. Snakes colored in this peculiar manner, as Mr. Wallace states on the authority of Dr. Giinther,® are found nowhere else in the world except in South America, and here no less than four genera occur. One of these, Elaps, is venomous; a second and widely distinct genus is doubtfully venomous, and the two others are quite harmless. ‘The species belonging to these dis- tinct genera inhabit the same districts, and are so like each other, that no one ‘but a naturalist would distinguish the harmless from the poisonous kinds.’’ Hence, as Mr. Wallace believes, the innocuous kinds have probably acquired their colors as a protection, on the principle of imitation ; for they would naturally be thought dangerous by their enemies. The cause, | however, of the bright colors of the venomous Elaps remains to be explained, and this may perhaps be sexual selection. 30 “ Rambles in Ceylon, ” in “ Annals and 64 Dr. Giinther, ‘* Reptiles of British In- Mag. of Nat. Hist.” 2d series, vol. ix. 1852, dia,” 2864, P 340. D+ 333 “ Westminster Rev.” July 1, 1867, P- 32 CHAP, X11.) REPTILES. 373 Snakes produce other sounds besides hissing. The deadly Fichis cavinata has on its sides some oblique rows of scales of a peculiar structure with serrated edges; and when this snake is excited, these scales are rubbed against each other, which produces ‘‘a curious prolonged, almost hissing sound.’’ ® With respect to the rattling of the rattlesnake, we have at last some definite information: for Prof. Aughey states, that on two occasions, being himself unseen, he watched from a little distance a rattlesnake coiled up with head erect, which continued to rattle at short intervals for half an hour: and at last he saw another snake approach, and when they met they paired. Hence he is satisfied that one of the uses of the rattle is to bring the sexes together. Unfortunately he did not as- certain whether it was the male or the female which remained stationary and called for the other. But it by no means follows from the above fact that the rattle may not be of use to these snakes in other ways, as a warning to animals which would otherwise attack them. Nor can I quite disbelieve the several accounts which have appeared of their thus paralyzing their prey with fear. Some other snakes also make a distinct noise by rapidly vibrating their tails against the surrounding stalks of plants ; and | have myself heard this in the case of a Tri- gonocephalus in South America. Lacertiia.—The males of some, probably of many, kinds of lizards fight together from rivalry. Thus the arboreal Anolis cristatellus of South America is extremely pugnacious: ‘‘ Dur- ing 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 fevy 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. Giinther has been able to ascertain, is the general rule with lizards of all kinds. The males alone of the Cyrtodactlylus vubidus of the Andaman Islands possesses pre-anal pores : and 63 Dr. Seer *“* Proc. Zoolog. Soc.” *5 Mr. N. L. Austen kept these animals alive for a considerable time; see “‘ Land o . 196. The American Naturalist,” 1873, p. and Water,” July, 1867, p. 9. 374 THE DESCENT OF MAN. SPART IL these pores, judging from analogy, probably serve to emit an odor. The sexes often differ greatly in various external characters. The male of the above-mentioned Anolis is furnished with a crest which runs along the back and tail, and can be erected at pleasure; but of this crest the female does not exhibit a trace. In the Indian Cophotis ceylanica, the female has a dorsal crest, though much less developed than in the male ; andso it is, as Dr. Giinther informs me, with the Fic. 33.—Sitana minor. Male with the females of many Iguanas, Cha- lar pouch expanded (from Giinther’s Reptiles of India ”). meleons, and other lizards. In some species, however, the crest is equally developed in both sexes, as in the /ewana tuberculata. In the genus Sitana, the males alone are furnished with a large throat-pouch (fig. 33), which can be folded up like a fan, and is colored blue, black, and red ; but these splendid colors are exhibited only during the pairing season. The female does not possess even a rudiment of this appendage. In the Anolis cristatellus, according to Mr. Austen, the throat-pouch, which is bright red marbled with yellow, is present in the female, though in a rudimental condition. Again, in certain other lizards, both sexes are equally well provided with throat-pouches. Here we see with species belonging to the same group, as in so many previous cases, the same character either confined to Fic. 34.—Ceratophora Stoddartik Upper figure, male; lower figure, fe male. the males or more largely developed in them than in the females, or again equally developed in both sexes. ‘The little lizards of the genus Draco, which glide through the air on their rib-supported parachutes, and which in the beauty of their colors baffle description, are furnished with skinny ap- pendages to the throat «‘ like the wattles of gallinaceous birds.”” These become erected when the animal is excited. ‘They oc- 8 Stoliczka, ‘‘ Journal of Asiatic Soc. of Bengal,” vol. xxxiv. 1870, p. 106. LE ee CU erhUrl Clee. CHAP. x11] REPTILES. 375 cur in both sexes, but are best developed when the male arrives at maturity, at which age the middle appendage is sometimes twice as long as the head. Most of the species likewise have a low crest running along the neck ; and this is much more developed in the full-grown males than in the fe- males or young males.™ A Chinese species is said to live in pairs during the spring ; Fic. 35.—Chamzleon bifurcus. Upper figure, male; lower figure, female. ‘¢and if one is caught, the other falls from the tree to the sround, and allows itself to be captured with impunity ’’—I presume from despair.® There are other and much more remarkable differences be- tween the sexes of certain lizards. The male of Ceratophora §7 All the foregoing statements and quo- nificent work on the ‘Reptiles of British tations, in regard to Cophotis, Sitana, and India,” Ray Soc. 1864, pp. 122, 130, 135. Draco, as well as the following facts in ree © Mr. Swinhoe, ‘ Proc. Zoolog. Soc.” ard to Ceratophora and Chameleon, are 1870, p. 240, ; WY mee Dr, Giinther himself, or from his mag- 379 THE DESCENT OF MAN. {PART 1 aspera bears on the extremity of his snout an appendage half as long as the head. It is cylindrical, covered with scales, flexi- ble, and apparently capable of erection; in the female it is quite rudimental. In a second species of the same genus a terminal scale forms a minute horn on the summit of the flex- ible appendage ; and in a third species (C. Stoddartit, fig. 34) the whole appendage is converted into a horn, which is usually of a white color, 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. Giin- ther has remarked to me, may be compared with the combs of gallinaceous birds, and apparently serve as ornaments. In the genus Cha- mzleon 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 Mada- gascar, is produced into two great, solid, bony — projections, covered with scales like the rest of the . 26,—Chameleon Owenii. Upper figure, male ; ‘ ; a lower figure, female. head; and of this wonderful modifica- tion of structure the female exhibits only a rudiment. Again, in Chameleon Owenitt (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 oonsist of an excrescence of bone covered with a smooth sheath, forming part of the general integuments of the body, so that they are identical in structure with those of a bull, goat, or other sheath- horned ruminant. Although the three horns differ so much in appearance from the two great prolongations of the skull in C. bifurcus, we can hardly doubt that they serve the same general purpose in the economy of these two animals. The first conjecture, which will occur to everyone, is that they are used by the males for fighting together ; and, as these animals EEE, rerlc ee erl eee CHAP XItJ REPTILES. 37? are very quarrelsome,™ this is probably a correct view. Mr T. W. Wood also informs me that he once watched two in dividuals of C. pumilus fighting violently on the branch of ¢ tree; they flung their heads about and tried to bite each other; they then rested for a time, and afterward continued their battle. With many lizards, the sexes differ slightly in color, 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 South 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, while 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 grayish green without spots.’’ We have seen that the males alone of Sitana possess a throat-pouch; and this is splendidly tinted with blue, black, and red. In the Proctotretus tenuis of Chile the male alone is marked with spots of blue, green, and coppery red.“ In many cases the males retain the same colors throughout the year, but in others they become much brighter during the breeding season ; I may give as an additional instance the Ca/otes maria, which at this season has a bright red head, the rest of the body being green.” Both sexes of many species are beautifully colored exactly alike ; and there is no reason to suppose that such colors are protective. No doubt with the bright green kinds, which live in the midst of vegetation, this color serves to conceal them, and in North Patagonia I saw a lizard (Proctotretus multimaculatus) which, when frightened, flattened its body, closed its eyes, and then from its mottled tints was hardly distinguishable from the surrounding sand. But the bright colors with which so many lizards are ornamented, as well as their various curious append- ages, were probably acquired by the males as an attraction, and then transmitted either to their male offspring alone, or te both sexes. Sexual selection, indeed, seems to have played 69 Dr. Bucholz, ‘Monatsbericht K. ‘Zoology of S, Africa: Reptiles,” by Sir Preuss. Akad.” Jan., 1874, p. 78. Andrew Smith, pl. 25. and 39. For the 70 Bell, “ History of British Reptiles,” Indian Calotes, see ‘* Reptiles of British 2d edit. 1849, p. 40. India,” by Dr. Giinther, p. 143. 1 For Proctotretus see ‘' Zoology of the. 72 Giinther in ‘* Proc. Zoolog. Sac.” 187% Voyage of the ‘ Beagle’: Reptiles,” by Mr. p. 778, with a colored figu?*- Be » P. 8. For the Lizards of S. Africa. sae . Sih i é 378 THE DESCENT OF MAN. (PART IL almost as important a part with reptiles as with birds; and the Jess conspicuous colors 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 XIII. SECONDARY SEXUAL CHARACTERS OF BIRDS. Sexual differences—Law of battle—Special weapons—Vocal organs— Instrumental music— Love-antics and dances—Decorations, permanent and seasonal—Double and single annual moults—Display of orna- ments by the males, SECONDARY 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 with each other. They charm the female by vocal or instrumental music of the most varied kinds. They are orna- mented by all sorts of combs, wattles, protuberances, horns, air-distended sacks, top-knots, naked shafts, plumes and lengthened feathers gracefully springing from all parts of the body. The beak and naked skin about the head, and the feathers, are often gorgeously colored. ‘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 odor, which we may suppose serves to charm or excite the female ; for that excellent observer, Mr. Ramsay,! says of the Australian musk-duck (Azziwra lobata) that ‘“‘the smell which the male emits during the summer months is confined to that sex, and in some individuals is re- tained throughout the year; I have never, even in the breed- ing season, shot a female which had any smell of musk.’’ So powerful is this odor during the pairing season, that it can be detected long before the bird can be seen.? On the whole, birds appear to be the most esthetic of all animals, excepting of course man, and they have nearly the same taste for the 1“ Phis,” vol. iii. (new series) 1867, p, a Gould. Z Pegayiie tics Birds of ooge ustralia,”’ 1865, vol. 1. DP. 3 —_—_—s CHAP. x111.J BIRDS, 379 beautiful as we have. This is shown by our enjoyment of the singing of birds, and by our women, both civilized and savage, decking their heads with borrowed plumes, and using gems which are hardly more brilliantly colored than the naked skin and wattles of certain birds. In man, however, when culti- vated, 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 ¢ommon in the lower, are rare in the higher, classes. Two humming-birds belonging to the genus Eustephanus, which inhabit the island of Juan Fernandez, were long thought to be specifically distinct, but are now known, as Mr. Gould informs me, to be the male and female of the same species, and they differ slightly in the form of the beak. In another genus of humming-birds (Gryfus), the beak of the male is serrated along the margin and hooked at the extremity, thus differing much from that of the female. In the Neomorpha of New Zealand, there is, as we have seen, a still wider difference in the form of _ the beak in relation to the manner of feeding of the two sexes. Something of the same kind has been observed with the gold- finch (Carduelis elegans), for I am assured by Mr. J. Jenner Weir that the birdcatchers can distinguish the males by their slightly longer beaks. The flocks of males are often found feeding on the seeds of the teazle (Dipsacus), which they can reach with their elongated beaks, while the females more com- ‘monly 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, how- ever, it is possible that the beaks of the males may have been first modified in relation to their contests with other males; and that this afterward 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 or 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 $ Quoted by Mr. Gould, “ Introduction tc the Trochilidz,” 1861, p. 29, 380 THE DESCENT OF MAN. (PART 11, — Oca, in speaking of another genus of humming-bird, says that two males rarely meet without a fierce aérial encounter: when kept in cages ‘‘ their fighting has mostly ended in the splitting of the tongue of one of the two, which then surely dies from being unable to feed.’’4 With Waders, the males of the common water-hen (Gadiinula chloropus) ‘* when pairing, fight violently for the females: they stand nearly upright in the water and strike with their feet.’’ ‘Two were seen to be thus engaged for half an hour, until one got hold of the head of the other, which would have been killed, had not the observer interfered ; the female all the time looking on as a quiet spec- tator.» Mr. Blyth informs me that the males of an allied bird (Gallicrex cristatus) are a third larger than the females, and are so pugnacious during the 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 purpose, for instance, . the bulbuls (Pycnonotus hemorrhous) which ‘fight with great spirit.’’ 6 The polygamous ruff (AZachetes pugnax, fig. 37) is notorious for his extreme pugnacity ; and in thespring, the males, which are considerably larger than the females, congregate day after day at a particular spot, where the females propose to lay their eggs. The fowlers discover these spots by the turf being trampled somewhat bare. Here they fight very much like game-cocks, seizing each other with their beaks and striking with their wings. ‘The great ruff of feathers round the neck is then erected, and, according to Col. Montagu, ‘‘ sweeps the ground as a shield to defend the more tender parts ; ’’ and this is the only instance known to me, in the case of birds, of any structure serving as a shield. ‘The ruff of feathers, however, from its varied and rich colors, probably serves in chief part as an ornament. Like most pugnacious birds, they seem always ready to fight, and when closely confined often kill each other ; but Montagu observed that their pugnacity becomes greater during the spring, when the long feathers on their necks are fully developed ; and at this period the least movement by any one bird provokes a general battle.‘ Or the pugnacity of web- footed birds, two instances will suffice: in Guiana ‘‘ bloody fights occur during the breeding season between the males of the wild musk-duck (Cazrina moschata) ; and where these fights 4 Gould, ibid. p. 52. 6 Jerdon, ‘ Birds of India,” 1863, vol. ii. 5 W. Thompson, ‘“‘The Natural History p. 96 of Ireland: Birds,’’ volume ii. 1850, page 7 Macgillivray, “Hist. Brit. Birds,” vol. 327: iv. 1852, pp. 177-181. . CHAP, XIII] LAW OF BATTLE. 381 have occurred the river is covered for some distance with feathers.’’® Birds which seem ill-adapted for fighting engage in fierce conflicts ; thus the stronger males of the pelican drive away the weaker ones, snapping with their huge beaks and giving heavy blows with their wings. Male snipe fight to- Fic. 37.—The Ruff or Machetes pugnax (from Brehm’s ‘‘ Thierleben ’’). gether, ‘‘ 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 aura- tus), although ‘‘ the hens are followed by even half a dozen of their gay suitors.’’ ° 8 Sir R. Schomburgk, in “ joumal of ® ‘Ornithological Biography,” vol. i. p+ Royal G-ographical Society,” vol. xiii. 1843, 191. For pelicans and snipes, see vol, ith p- 31- pp- 138, 477: 382 THE DESCENT OF MAN. [PART 11. The males of many birds are larger than the females, and this no doubt is the result of the advantage gained by the larger and stronger males over their rivals during many gener- ations. 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 Crncloramphus cruralis (allied to our pipits) are by measurement actually twice as large as their respective females.'? With many other birds the females are larger than the males ; and, as formerly remarked, the explanation often given, namely, that the females have most of the work in feeding their young, will not suffice. In some few cases, as we shall hereafter see, the females apparently have acquired their greater size and strength for the sake of conquering other females and obtaining possession of the males. The males of many gallinaceous birds, especially of the polygamous kinds, are furnished with special weapons for fighting with their rivals, namely, spurs, which can be used with fearful effect. It has been recorded by a trustworthy writer “ that in Derbyshire a kite struck at a game-hen accom- panied by her chickens, when the cock rushed to the rescue, and drove his spur right through the eye and skull of the ag- gressor. ‘The spur was with difficulty drawn from the skull, and as the kite, though dead, retained his grasp, the two birds were firmly locked together ; but the cock when disentangled was very little injured. The invincible courage of the game- cock is notorious: a gentleman who long ago witnessed the brutal scene, told me that a bird had both its legs broken by some accident in the cock-pit, and the owner laid a wager that if the legs could be spliced so that the bird could stand up- right, he would continue fighting. This was effected on the spot, and the bird fought with undaunted courage until he re- ceived his death-stroke. In Ceylon a closely allied, wild species, the Gallus Stan/eyi, 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 quarrelsome, ‘‘ that the scars of former fights disfigure the breast of almost every bird you kill.’’ ® The males of almost all gallinaceous birds, even those which 10 Gould, ‘‘ Handbook of Birds of Aus- 12 Layard, “ Annals Pas Mag. of Nat. tralia, ” vol. i. p. 395, vol. ii. p. 383. Hist.” vol, xiv. 1854, p 1 Mr. Hewitt in the “ Poultry Book by 3% Jerdon, ‘‘ Birds me india,” vol. iji. pe Tegenncier,” 1866, p. 137- 574, ra . ey eS, CHAP. XIil.) LAW OF BATTLE, 333 are not furnished with spurs, engage during the breeding season in fierce conflicts. ‘The Capercailzie and Black-cock ( Zetrao urogallus and Z. tetrix), which are both polygamists, have regular appointed places, where during many weeks they con- gregate in numbers to fight together and to display their charms before the females. Dr. W. Kovalevsky informs me that in Russia he has seen the snow all bloody oan the arenas where the capercailzie have fought; and the black-cocks ‘‘make the feathers fly in every direction,’’ when severai ‘‘ engage ina bat- tle 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 agains: the ground that the chin feathers are rubbed off. During these movements he beats his wings and turns round and round. ‘The more ardent he grows, the more lively he becomes, until at last the bird appears like a frantic creature.’’ At such times the black- cocks are so absorbed that they become almost blind and deaf, but less so than the capercailzie: hence bird after bird may be shot on the same spot, or even caught by the hand. After performing these antics the males begin to fight: and the same black-cock, in order to prove his strength over several antago- nists, will visit in the course of one morning several Baiz-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 Rev. W. Darwin Fox informs tae that at some little dis- tance from Chester two peacocks became so excited while 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 pro- vided, is generally single; but Polyplectron (see fig. 51, p. 417) has two or more on each leg; and one of the Blood- pheasants (/thaginis cruentus) has been seen with five spurs. The spurs are generally confined to the male, being represented by mere knobs or rudiments in the female; but the females of the Java peacock (Pavo muticus) and, as I am informed by 34 Brehm, “TIllust. Thierleben,” 1867, B. are taker from L. Lloyd, ‘The Game Birds fv. s. 351. Someoftheforegoingstatements of Sweden,” etc., 1867, Pp. 7 284 THE DESCENT OF MAN, . {PART IL Mr. Blyth, of the small fire-backed pheasant (Luplocamus ery- thropthalmus) possess spurs. In Galloperdix it is usual for the males to have two spurs, and for the females to have only one on each leg.® Hence spurs may be considered as a masculine structure, which has been occasionally more or less transferred to the females. Like most other secondary sexual characters, the spurs are highly variable, both in number and develop- ment, in the same species. Various birds have spurs on their wings. But the Egyptian goose (Chenalopex egptiacus) has only ‘‘ bare obtuse knobs,”’ and these probably show us the have been developed in other goose, Plectropterus gambensts, first steps by which true spurs species. In the spur-winged the males have much. larger spurs than the females ; and they use them, as I am informed by Mr. Bartlett, in fighting together, so that, in this case, the wing-spurs serve as sexual weapons ; but, according to Living- stone, they are chiefly used in the defence of the young. ‘The Palamedea (fig. 38) is armed with a pair of spurs on each wing; and these are such formidable weapons, that a single blow has been known to drive a dog howling away. But it dses not appear that the spurs in this case, or in that of some of the spur-winged rails, are larger in the male than in the female. '¢ common peewit (Vanellus cri. In certain plovers, however, the wing-spurs must be considered as a sexual character. Thus in the male of our /atus) the tubercle on the shoul- der of the wing becomes more prominent during the breeding season, and the males fight together. In some species of Lobi- vanellus a similar tubercle becomes developed during the breeding season ‘‘ into a short horny spur.’’ In the Australian L. lobatus both sexes have spurs, but these are much larger in the males than in the females. In an allied bird, the Hop- lopterus arimatus, 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 times with fatal results. mies. 15 Jerdon, “ Birds of India: on Ithaginis,”’ vol. ili. p. 523; on Galloperdix, p. 541. 16 For the Egyptian goose. see Macgilli- vray, ‘‘ British Birds,” vol. iv. p. 639. ‘For Plectropterus, ‘‘ Livingstone’s Travels.” p- 254. For. Palamedea, Brehm’s ‘* Thier- leben,” B.-iv. s. 740. See also on this bird Azara, “ Voyages dans l’ Amérique mérid.” tom. iv. 1809, Pp. 179, 253+ sideways at each other, some- Thus also they drive away other ene- 17 See, on our peewit, Mr. R. Carr in ‘*Land and Water,” August 8, 1868, p. 46. In_ regard to Lobivanellus, see Jerdon’s “Birds of India,” vol. iii, p. 647. and Gould’s ‘‘ Handbook of Birds of Austra- lia,” vol. ii. p. 220, For the Holopterus, see Be Allen in the “ Ibis,’”’ vel. v. 1863, P 15 ~~ ees lS se! — > Ay CHAP. x11} LAW OF BATTLE, 385 The season of love is that of dattle; but the males of some birds, as of the game-fowl and ruff, and even the young males ea { ~ yi s \ cj s BiG. 38.—Palamedea cornuta (from Brehm), showing the double wing-spurs, and the filament on the head. of the wild turkey and grouse, are ready to fight whenever 18 Audubon, ‘* Ornith, Biography,” vol. ii. p. 492; vol. i. pp. 4-13. (Q)—Vol. 3 386 THE DESCENT OF MAN, (Pare 1. they meet. The presence of the female is the ¢eterima belli causa. ‘The Bengali baboos make the pretty little males of the amadavat (/strelda amandava) fight together by placing three small cages in a row, with a female in the middle; after a little time the two males are turned loose, and immediately a desperate battle ensues. When many males congregate at the same appointed spot and fight together, as in the case of grouse and various other birds, they are generally attended by the females, which afterward pair with the victorious com- batants. But in some cases the pairing precedes instead of succeeding the combat: thus, according to Audubon,*! several males of the Virginian goat-sucker (Caprimulgus virginianus) ‘*court, in a highly entertaining manner, the female, and no sooner lias she made her choice than her approved gives chase to all intruders, and drives them beyond his dominions.’’ Gen- erally the males try to drive away or kill their rivals before they pair. It does not, however, appear that the females in- variably prefer the victorious males. I have indeed been as- sured by Dr.W. Kovalevsky that the female capercailzie some- times steals away with a young male who has not dared to enter the arena with the older cocks, in the same manner as occasion- ally happens with the does of the red deer in Scotland. When two males contend in presence of a single female, the victor, no doubt, commonly gains his desire ; but some of these battles are caused by wandering males trying to distract the peace of an already mated pair.” 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 deco- rated with various ornaments, which often become more brill- iant during the breeding season. and which are sedulously displayed before the females. The males also endeavor 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 com- 19 Mr. Blyth, ‘Land and Water,” 1867, . 212. . 20 Richardson on Tetrao umbellus, ‘‘Fauna Bor. Amer.: Birds,” 1831, Pp. 343. L. Lloyd, “‘ Game Birds of Sweden,” 1867, pp. 22, 79, on the capercailzie and black- cock. ben,” etc., B. iv. s. 352) that in Germany the gray-hens do not generally attend the Balzen of the black-cocks, but this is an ex- Brehm, however, asserts (‘‘Thierle- 275 ception to the common rule; possibly the hens may lie hidden in the surrounding bushes, as is known to be the case with the gray-hens in Scandinavia, and with other species in North America. bs 21 ‘Ornithological Biography,” vol. ii. p. 75- e 22 Brehm, ‘‘Thierleben,” etc., B. iv. 1867, p. 990. Audubon, ‘ Ornith. Bioge raphy,” vol. i. p. 492. 3 se aw ee EE ee - _ CHAP. XItt.) LAW OF BATTLE, 3897 pelled to yield to the victorious males. It is more probable that the females are excited, either before or after the conflict, by certain males, and thus unconsciously prefer them. In the case of Zetrao umbellus, a good observer * goes so far as to be- lieve that the battles of the males ‘‘ are all asham, 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 Ze¢rao cupido of the United States, about a score of males assemble at a particular spot, and, strutting about, make the whole air resound with their extraordinary noises. At the first answer from afemale 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 (Sturnella ludoviciana) the males engage in fierce conflicts, ‘‘ but at the sight of a femaie they all fly after her as if mad.’’ * Vocal and instrumental music.—With birds the voice serves to express various emotions, such as distress, fear, anger, tri- umph, or mere happiness. It is apparently sometimies used to excite terror, as in the case of the hissing noise made vy some nestling-birds. Audubon * relates that a night-heron (4raca 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 to- gether by chirp answering chirp. During the nocturnal mi- grations 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, 8¢ “Land and Water,” July 25, 1868, p. whey ** Ornithological Biograph.” vol. v. p. 24. I. 24 Audupon’s “ Ornitholog. Biography ;’ 6 The Hon. Daines Barrington, “ Philo on Zetrao cufpido, vol. ii, p. 492; On the soph. Transact.” 1773, (2. 252. Sturons, vol, ti. p. 279, er 8388 THE DESCENT OF MAN. [PART 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 breeding 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. Bechste‘n, 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 ttend to each other’s song. Mr. Weir has told me of the cae of a bullfinch which had been taught to pipe a German waltz, and who was so good a performer that he cost cen guineas; when this bird was first introduced into a room where other birds were kept and he began to sing, all the others, consisting of about twenty linnets and canaries, ranged themselves on the nearest side of their cages, and listened with the greatest interest to the new performer. Many naturalists believe that the singing of birds is almost exclusively ‘< the ef- fect of rivalry and emulation,’’ and not for the sake of charm- ing their mates. This was the opinion of Daines Barrington and White of Selborne, who both especially attended to this subject.” Barrington, however, admits that ‘‘ superiority in song gives to birds an amazing ascendancy over others, as is well known to bird-catchers.”’ It is certain that there isan intense degree cf rivalry between the males in their singing. Bird-fanciers match their birds to see which will sing longest ; and I was told by Mr. Yarrell that a first-rate bird will sometimes sing till he drops down almost 2 “ Ornithological Dictionary,” 1833, p. best singing males generally get a mate 475- first, when they are bred in the same room,’? 28 «“*Naturgeschichte der Stubenvégel,” 29 « Philosophical Transactions,” "77% Bs 3840, s. 4. Mr. Harrison Weir likewise 263. White’s “ Natural History writes tome: “I am informed that the borne,” 1825, vol i. p. 246 - ——=— =