bibliotheek
r
;
*
THE DESCENT OF MAN,
AND
SELECTION IN RELATION TO SEX.
BY THE SAME AUTHOR.
ON THE ORIGIN OF SPECIES BY MEANS OF NATURAL
SELECTION ; or. The Preservation op Favoured Races in the Struggle for Life; Fifth Edition ( Tenth Thousand), with Additions and Corrections. 1869. Murray.
THE VARIATION OF ANIMALS AND PLANTS UNDER
DOMESTICATION. In two vola. With Illustrations. 1868. Murray.
ON THE VARIOUS CONTRIVANCES by which BRITISH
AND FOREIGN ORCHIDS ARK FERTILISED BY INSECTS; and on the Goon Effects of Chossing. With numerous Woodcuts. Murray.
A NATURALIST’S VOYAGE ROUND THE WORLD ; or,
A Journal op Researches into the Natural History and Geology of the Countries visited during the voyage of H.M.S, * Bougie.' under the command of Captain FitzRoy, R.N. Eleventh Thousand. Murray.
ON THE STRUCTURE AND DISTRIBUTION OF CORAL
REEFS. Smith, Elder, & Co.
GEOLOGICAL OBSERVATIONS ON VOLCANIC ISLANDS.
Smith, Elder, & Co.
GEOLOGICAL OBSERVATIONS ON SOUTH AMERICA.
Smith, Elder, & Co.
A MONOGRAPH OF THE CIRRIPEDIA. With numerous
Illustrations. 2 vols. 8vo. Hardwick e.
ON THE MOVEMENTS AND HABITS OF CLIMBING
PLANTS. With Woodcuts. Williams & Norgate,
LONDON: PRINTED BY WILLTAM CLOWES AND SONS, STAMFORD STREET, AND CHARING CROSS.
Introduction
Page 1-5
CONTENTS.
PAET I.
ON THE DESCENT OF MAN.
CHAPTER I.
The Evidence op the Descent of man from some Lower Form.
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, hones, reproductive organs, &c. The hearing of these three great classes of facts on the origin of
man
9-33
CHAPTER II.
Comparison of the Mental Powers of Man and tiie 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 Ima- gination Reason — Progressive improvement Tools and
weapons used by animals — Language feelf-consciousness Sense of beauty— Belief in God, spiritual agencies, superstitions
34-69
CHAPTER HI.
Comparison of the Mental Powers of Man and the Lower Animals — continued.
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
VI
CONTENTS OP VOL. 1.
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 — Trans- mission of moral tendencies — Summary .. .. Tage 7C-1C6
CHAPTEE IV.
Off the Manner op Development of Man prom some Lower Form.
Variability of body and mind in man — Inheritance — Causes of variability — Laws of variation the same in man as in the lower animals — Direct action of the conditions of life — Effects of the increased use and disuse of parts — Arrested development — Ke- version — Correlated variation — Late 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 hecoming 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 107-157
CHAPTER V.
On the Development of the Intellectual and Moral Faculties during Primeval and Civilised Times.
The advancement of the intellectual powers through natural selec- tion—Importance of imitation — Social and moral faculties — Their development within the limits of the same tribe — Natural selection as affecting civilised nations — Evidence that civilised nations were once barbarous 158-184
CHAPTEE VI.
On the Affinities and Genealogy of Man.
Position of man in the animal series — The natural system genea- logical— Adaptive characters of slight value — Similar small points of resemblance between man and the Quadrumana — Bank of man in the natural system — Birthplace and antiquity
CONTENTS OF VOL. I. Y11
of man — Absence of fossil connecting-links — Lower stages in the genealogy of man, as inferred, firstly from his affinities and secondly from liis structure — Early androgynous condition of the Vertebrata — Conclusion .. .. : .. •• Page 185-213
CHAPTER VII.
On the Races of Man.
I he nature and value of specific characters — Application to the races of man — Arguments in favour of, and opposed to, ranking the so-called races of man as distinct species — Sub-species— Mono- genists and polygenists — 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 raco not descended from a single pair The ex- tinction of races — The formation of races — The effects of cross- ing— Slight influence of the direct action of the conditions of lile — - Slight or no influence of natural selection — Sexual selection
214-250
PART II.
SEXUAL SELECTION.
CHAPTER VIII.
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 selection — Inheritance at corresponding periods of life, at corresponding seasons of the year, and as limited by sex — Relations between the several forms of inheritance — Causes why one sex and the young are not modified through sexual selection — Supplement on the proportional numbers ol the two sexes throughout the animal kingdom — On the limita- tation of the numbers of the two sexes through natural selection
253-320
Vlll
CONTENTS OF YOL. I.
CHAPTER IX.
Secondary Sexual Characters in the Lower Classes of the Animal Kingdom.
These characters absent in the lowest classes — Brilliant colours — Mollnsca — Annelids — Crustacea, secondary sexual characters strongly developed ; dimorphism ; colour ; characters not acquired before maturity — Spiders, sexual colours of ; stridulation by the males — Myriapoda Page 321-340
CHAPTER X.
Secondary Sexual Characters of Insecst.
Diversified structures possessed by the males for seizing the females — Differences betvyeen the sexes, of which the meaning is not understood — Difference in size between the sexes — Thysanura — Diptera — Hemiptera' — Ilomoptera, musical powers possessed by tho males alone — Orthoptera, musical instruments of the males, much diversified in structure ; pugnacity ; colours — Neuroptera, sexual differences in colour — Hymcnoptera, pug- nacity and colours— Coleoptera, colours ; furnished with great horns, apparently as an ornament; battles; stridulating organ.', generally common to both sexes 341-385
CHAPTER XI.
Insects, continued. — Order Letidoi’TEUA.
Courtship of butterflies — Battles — Ticking noise — Colours com- mon to both sexes, or more brilliant in the males — Examples — Not due to the direct action of the conditions of life — Colours adapted for protection — Colours of moths — Display — Per- ceptive powers of the Lepidoptera — Variability — Causes of the difference in colour between the males and females — Mimickry, female butterflies more brilliantly coloured than tho males — Bright colours of caterpillars — Summary and concluding re- marks on the secondary sexual characters of insects — Birds and insects compared 3bC-423
THE DESCENT OF MAN;
AND ON
SELECTION IN RELATION TO SEX.
INTRODUCTION.
The nature of the following work will he best under- stood 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 suffi- cient to indicate, in the first edition of my ‘ Origin of Species,’ that by this work “ light would be thrown on “ the origin of man and his history and this implies that man must be included with other organic beings in any general conclusion respecting his manner of appear- ance on this earth. Now the case wears a wholly dif- ferent aspect. When a naturalist like Carl \ ogt ven- tures to say in his address as President of the National Institution of Geneva (I860), “ personae, en Europe “ au moins, n’ose plus soutenir la creation independante “ et de toutes pieces, des especes,” it is manifest that at least a large number of naturalists must admit that species are the modified descendants of other species ;
VOL. i.
B
2
INTRODUCTION.
and this especially holds good with the younger and rising naturalists. The greater number accept the agency of natural selection; though some urge, whether with justice the future must decide, that I have greatly overrated its importance. Of the older and honoured chiefs in natural science, many unfortunately are still opposed to evolution in every form.
In consequence of the views now adopted by most naturalists, and which will ultimately, as in every other case, be followed by other men, 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 appli- cable 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 argu- ments derived from the nature of the affinities which connect together whole groups of organisms — their geo- graphical distribution in past and present times, and their geological succession. The homological structure, embryological development, and rudimentary organs of a species, whether it be man or any other animal, to which our attention may be directed, remain to be con- sidered; but these great classes of facts afford, as it appears to me, ample and conclusive evidence in favour of the principle of gradual evolution. The strong sup- port derived from the other arguments should, however, always be kept before the mind.
The sole object of this work is to consider, firstly, whether man, like every other species, is descended from some pre-existing form ; secondly, the manner of
INTRODUCTION.
3
his development ; and thirdly, the value of the differ- ('nces between the so-called races of man. As I shall confine myself to these points, it will not he necessary to describe in detail the differences between the several races — an enormous subject which has been fully dis- cussed in many valuable works. The high antiquity of umn has recently been demonstrated by the labours °f a host of eminent men, beginning with M. Boucher (1° Perthes ; and this is the indispensable basis for Understanding his origin. I shall, therefore, take this conclusion for granted, and may refer my readers to the admirable treatises of Sir Charles Lyell, Sir John Lubbock, and others. Nor shall I have occasion to do lnore than to allude to the amount of difference between unxn and the anthropomorphous apes ; for Prof. Huxley, la the opinion of most competent judges, has conclu- sively shewn that in every single visible character man differs less from the higher apes than these do from the lower members of the same order of Primates.
This work contains hardly any original facts in regard to man; but as the conclusions at which I arrived, after drawing up a rough draft, appeared to rn° interesting, 1 thought that they might interest others. It has often and confidently been asserted, that mans 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, wh° so positively assert that this or that problem will never he sol ved by science. The conclusion that man is the co-descendant with other species of some ancient, "or, and extinct form, is not in any degree new. La- ir 2
4
INTRODUCTION.
marck long ago came to this conclusion, which has lately been maintained by several eminent naturalists and philosophers ; for instance by Wallace, Huxley, Lyell, Yogt, Lubbock, Buchner, Hollo, &c.,' and especially by Haokel. This last naturalist, besides his great work, ‘ Generelle Morphologic ’ (1866), has recently (1868, with a second edit, in 1S70), published his ‘Naturliche Schopfungsgeschiehte,’ in which he fully discusses the genealogy of man. If this work had appeared before my essay had been written, . I should probably never have completed it. Almost all the conclusions at which I have arrived I find confirmed by this naturalist, whose knowledge on many points is much fuller than mine. Wherever I have added any fact or view from Prof. Hackel’s writings, I give his authority in the text, other statements I leave as they originally stood in my manu- script, 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 pro- bable that sexual selection has played an important part in differentiating the races of man; but in my
1 As the works of the first-named authors are so well known, I need not pivo the titles ; but as those of the latter are less well known in England, I will give them ‘ Seehs Vorlesungen uber die Darwin’- sche Thcorie:’ zweite Auflage, 1868, von Dr. L. Buchner; translated into French under the titlo * Conferences sur la Thermo Darwinienue,’ 1861). *Der Meusch, im Licit tu der Darwin’sehe Lehre,’ 1865, von Dr, F. Roll,, I will not attempt to give references to all the authors who have taken the same side of the question. Thus G. Canestrini has published (‘Annuario della Soe. d. Nat.,’ Modena, 1867, p. 81) a very curious paper on rudimentary characters, as bearing on the origin of man. Another work lias (1869) been published by Dr. Barrage Francesco, bearing in Italian the title of “ Man, made in the image of God, was also made in tiie image of the ape.”
INTRODUCTION.
5
Origin of Species’ (first edition, p. 199) I contented lnyself by merely alluding to this belief. When I came to aPI>ly this view to man, I found it indispensable to treat the whole subject iu full detail.2 Consequently tire second part of the present work, treating of sexual election, has extended to an inordinate length, com- pared 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 dl|d the lower animals. My attention was called to this object many years ago by Sir Charles Bell’s admirable work. This illustrious anatomist maintains that man ls endowed with certain muscles solely for the sake expressing his emotions. As this view is obviously °Pposed to the belief that man is descended from some °ther and lower form, it was necessary for me to consider !t- I likewise wished to ascertain how far the emotions dre expressed in the same manner by the different races °f man. But owing to the length of the present work,
have thought it better to reserve my essay, which is Partially completed, for separate publication.
< q ) r°e Hackel ia the sole author who, since the publication of the th ^as discussed, in his various works, in a very able manner
e subject of sexual selection, and has seen its full importance.
Part I.
THE descent or origin of man.
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: V |
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Part I.— THE DESCENT OF MAN.
CHAPTER I.
: j 1
The Evidence of the Descent of Man from some Lower Torh.
Mature of the evidence hearing on the origin of man — Homologous, structures in man and the lower animals — Miscellaneous points of correspondence — Development — Rudimentary structures, muscles, sense-organs, hair, bones, reproductive organs, &c. — The hearing of these three great classes of facts on the origin of naan.
He who wishes to decide whether man is the modified descendant of some pre-existing form, would probably first enquire whether man varies, however slightly, in J°dily structure and in mental faculties; and if so, whether the variations are transmitted to his offspring ln accordance with the laws which prevail with the lower animals; such as that of the transmission of characters to the same age or sex. Again, are the variations the re- sult, 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 in- stance by correlation, the inherited effects of use and disuse, &c. ? Is man subject to similar malconformations, le ^sult of arrested development, of reduplication of parts, &c., and does he display in any of his anomalies reversion to some former and ancient type of structure ?
nnght also naturally be enquired whether man, like S(J many other animals, has given rise to varieties and SU traces, differing but slightly from each other, or to
10
THE DESCENT OF MAN.
Part I.
races differing so much that they must be classed as doubtful species ? How are such races distributed over the world ; and how, when crossed, do they react on each other, both in the first and succeeding genera- tions ? And so with many other points.
Ihe enquirer would next come to the important point, whether man tends to increase at so rapid a rate, as to lead to occasional severe struggles for existence, and consequently to beneficial variations, whether in body or mind, being preserved, and injurious ones eliminated. Do the races or species of men, whichever term may be applied, encroach on and replace each other, 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 conve- niently 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 the two succeeding chapters the mental powers of man, in comparison with those of the lower animals, will be con- sidered.
The Bodily Structure of Man.— It is notorious that man is constructed on the same general type or model with other mammals. All the bones in his skeleton can be compared with corresponding bones in a monkey, bat, or seal. So it is with his muscles, nerves, blood- vessels and internal viscera. The brain, the most im- portant of all the organs, follows the same law, as shewn by Huxley and other anatomists. Bischoff,’ who is a hostile witness, admits that every chief fissure and fold
‘ (frossbirnwiudungen des Menschen,’ 18CS, s. 9U.
Chap. i.
HOMOLOGICAL STRUCTURE.
11
|u d'e brain of man has its analogy in that of the orang ; ut he adds that at no period of development do their JI'ains perfectly agree ; nor could this be expected, for otherwise their mental powers would have been the same. ' ulpian 2 remarks : “ Les differences reelles qui existent entre l’encephale de Fhomme et celui des singes supe- rieurs, sont bien minimes. II ne faut pas se faire ^’illusions a cet egard. L’homme est bien plus pres ‘ des singes anthropomorplies par les caracteres anato- ‘ miques de son cerveau que ceux-ci ne le sont non- soulement des autres mammiferes, inais memes de certains quadrumanes, des guenons ct des macaques.” 11 1 it would be superfluous here to give further details the correspondence between man and the higher '“animals 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 struc- tlxie> by which this correspondence or relationship is "oil shewn.
Man is liable to receive from the lower animals, and lo communicate to them, certain diseases as hydro- P mbia, variola, the glanders, &c. ; and this fact proves ae dose similarity of their tissues and blood, both in '“mute structure and composition, far more plainly than f oes their comparison under the best microscope, or by 16 a'd of the best chemical analysis. Monkeys are 'able to many of the same non-contagious diseases as we j*le’ thus Rengger,3 who carefully observed for a long ^ 11116 t,le Celus Azarse, in its native land, found it liable 0 cata'T'h, with the usual symptoms, and which when
, sur 'a Phys.’ 1866, p. 890, as quoted by M. Dally, ‘L’Ordre
a f£matea et h Transformisme,' 1868, p. 29.
- aturgesehiclite der Saugethiere von Paraguay,’ 1830, s. 50.
12
THE DESCENT OF MAN.
Part I.
often recurrent led to consumption. These monkeys suffered also from apoplexy, inflammation of the bowels, and cataract in the eye. The younger ones when shed- ding their milk-teeth often died from fever. Medicines produced the same effect on them as on us. Many kinds oi monkeys have a strong taste for tea, coffee, and spirituous liquors: they will also, as I have myself seen, smoke tobacco with pleasure. Brehm asserts that the natives of north-eastern Africa catch the wild baboons by exposing vessels with strong beer, by which they are made drunk. He has seen some of these animals, which he kept in confinement, in this state ; and he gives a laughable account of their behaviour and strange grimaces. On the following morning they were very cross and dismal; they held their aching heads with both hands and wore a most pitiable expression : when beer or wine was offered them, they turned away with disgust, but relished the juice ot lemons.4 An American monkey, an Ateles, alter getting drunk on brandy, would never touch it again, and thus was wiser than many men. these trifling facts prove how similar the nerves of taste must be in monkeys and man, and how simi- larly their whole nervous system is affected.
Man is infested with internal parasites, sometimes causing fatal effects, and is plagued by external para- sites, all of which belong to the same genera or families with those infesting other mammals. Man is subject like other mammals, birds, and even insects, to that mys- terious law, which causes certain normal processes, such as gestation, as well as the maturation and duration of various diseases, to follow lunar periods.5 His wounds
- Brehm, ‘ Thiorlebcn,’ B. i. 1864, s. 75, 86. On the Ateles, s. 105 For other analogous statements, see s. 25, 107.
“ Wltl1 respect to insects see Dr. Laycoek ‘ On a General Law of Vital Periodicity,’ British Association, 1842. Dr. Macculloch, ‘ Silli-
(’hap. I.
HOMOLOGICAL STKUCTUBE.
13
a*e rePaii'ed by the same process of healing ; and the s nmps left after the amputation of his limbs occa- sionally possess, especially during an early embryonic Period, some power of regeneration, as in the lowest ailimals.6
The whole process of that most important function, . le reproduction of the species, is strikingly the same 111 all mammals, from the first act of courtship by the rrrale 7 to the birth and nurturing of the young. Mon- Keys are born in almost as helpless a condition as our infants; and in certain genera the young differ " , f as much in appearance from the adults, as do our ( ‘ii^ren from their full-grown parents.8 It has been 'n-ged by some writers as an important distinction, that 'Vlt 1 num tlm young arriye at maturity at a much later ttSe than with any other animal : but if we look to the manltind which inhabit tropical countries the 1 eience is not great, for the orang is believed not to >e a( u't till the age of from ten to fifteen years.9 Man
a American Journal of Science,’ vol. xvii. p. 305, lias seen
dog suffering from tertian ague.
At • 'ave giveu the evidence on this head iu my ‘Variation of ; 8 au<t t’hints under Domestication,’ vol. ii. p. 10.
“ fern' °rCS ° <t'vei'sis generibus Quadrumanorum sine dubio dignoscunt “ Mr vS lunianas a niaribua. Primurn, credo. odoratu, postea aspectu. ‘ iuni °uatt, qui diu in Hortis Zoulogicis (Hestiariis) medians animal- « '1 erat’ va' in rebus observandis can Inis ct sngax, hoc mibi certissime
‘ ‘ Sir A ' l °urili°res ejusdem loci ct alii e ministris coniinnaverunt. “ trigs’ ", reW ^m'ih et BreTim notabaut idem in Cynocephalo. Illus- « turii lmUS ^llvier etiam narrat inidta do line re qua nt opiuor nihil “uninhT Pvrte&* ir"licari inter omnia bominibus et Qnadrmnanis com- “ aspectu f .mt 0Dim Cynoceplialum queudsin iu furorem incidere “ a), enuuanm aliquarum, sod nequaquam accondi tauto furore “ advnnoU j S‘ ®etnl)er eligebat juniores, et dignoscebnt iu turba, et 8Tbi V0CP' qostuquo.”
tbropomQ^ ornarb is made with respect to Cynocephalus and the an- Nat de« tv? 10US apes by Geoffrey Saint-Hilaire and F, Cuvier, ‘Hist, a H^®amm|teres,’ tom. i. 1824.
ey> Man’s Place in Nature,’ I8G3, p. 34.
14
THE DESCENT OF MAN.
Part I.
differs from woman in size, bodily strength, hairyness, &c., as well as in mind, in the same manner as do the two sexes of many mammals. It is, in short, scarcely possible to exaggerate the close correspondence in gene- ral structure, in the minute structure of the tissues, in chemical composition and in constitution, between man and the higher animals, especially the anthropomor- phous apes.
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 verte- brate kingdom. At this period the arteries run in arch- like branches, as if to carry the blood to branchim which are not present in the higher vertebrata, though the slits on the sides of the neck still remain (/, g, fig. 1), marking their former position. At a somewhat later period, when the extremities are developed, “the feet of “ lizards and mammals,” as the illustrious Yon Baer remarks, “ the wings and feet of birds, no less than the “ hands and feet of man, all arise from the same funda- “ mental form.” It is, says Prof. Huxley,10 “ quite in “ the later stages of development that the young human “ being presents marked differences from the young “ ape, while the latter departs as much from the dog “ in its developments, as the man does. Startling as
this Inst assertion may appear to be, it is demonstrably “ true.”
As some of my readers may never have seen a draw- ing of an embryo, I have given one of man and another of a dog, at about the same early stage of development,
10 * Man’s Place in Nature,’ 1863, p. 67.
ClIAP. I.
embryonic development.
15
% i.
-L
' Per Rgnre human embryo, from Kcleer.
from Iiischoft.
Lower figure that of a
(log.
, c- HlndS^^n-iad 'o'fitata. cerebeHum,
d- Rye. e- Rar.
f- Flr»t visceral arch.
g. Second visceral arch.
H. Vertebral columns and muscles in process of development. i. Anterior )
K. Posterior j extremities.
L. Tail or os coccyx.
10
THE DESCENT OF MAN.
Part 1.
carefully copied from two works of undoubted accu- racy.11
After tlie foregoing statements made by such high authorities, it would be superfluous on my part to give a number of borrowed details, shewing that the embryo of man closely resembles that of other mammals. It may, however, be added that the human embryo like- wise resembles in various points of structure cer- tain low forms when adult. For instance, the heart at first exists as a simple pulsating vessel ; the excreta are voided through a cloaeal passage; and the os coccyx projects like a true tail, “ extending considerably “ beyond the rudimentary legs.” 12 In the embryos of al l air-breathing vertebrates, certain glands called the cor- pora Wolffiana, correspond with and act like the kidneys of mature fishes.13 Even at a later embryonic period, some striking resemblances between man and the lower animals may be observed. Bischoff says that the con- volutions of the brain in a human foetus at the end of the seventh month reach about the same stage of deve- lopment as in a baboon when adult.14 The great toe, as Prof. Owen remarks,15 “ which forms the fulcrum when “ standing or walking, is perhaps the most characteristic
11 The human embryo (upper fig.) is from Ecker, ‘leones Phys.,’ 1851-1859, tab. xxx. fig. 2. This embryo was ten lines in length, so that the drawing is much magnified. The embryo of the dog is from Bischoff, ‘ Entwieklungsgeschiohte dcs Hundc-Eies,’ 1845, tab. xi. fig. 42 B. This drawing is five times magnified, the embryo being 25 days old. The internal viscera have been omitted, and the uterine appen- dages in both drawings removed. I was directed to these figures by Prof. Huxley, from whose work, ‘ Man's Place in Nature,’ the idea of giving them was taken, Hacked has also given analogous drawings in his ‘ Scliopfutigsgeschichte.’
12 Prof. Wyman in ‘Proc. of American Acad, of Sciences,’ vol. iv. 1860, p. 17.
13 Owen, ‘ Anatomy of Vertebrates,’ vol. i. p. 533.
14 ‘Die Grosshirnwindungen des Menschen,’ 1868, s. 95.
15 ‘Anatomy of Vertebrates,’ vol. ii. p. 553.
Chap. j_
RUDIMENTS.
17
^ peculiarity in the human structure;” but in an em- «, 1°’ about an inch in length, Prof. Wyman 16 found <« . at tllc gi'eat toe was shorter than the others, and, (( instead of being parallel to them, projected at an „ ^ e h'mn the side of the foot, thus corresponding „ "ltb ii'c permanent condition of this part in the quadrumana.” I will conclude with a quotation from ( ';'xley,17 who after asking, does man originate in a '/ ei'eut way from a dog, bird, frog or fish? says, “ the t( 'I'Piy is not doubtful for a moment; without question, (( 16 mode of origin and the early stages of the develop- (i !Uent °f man are identical with those of the animals „ lllJVUediat(‘ly below him in the scale : without a doubt <( 111 ^'ese respects, he is far nearer to apes, than the apes are to the dog.”
Rudiments. — This subject, though not intrinsically sr JlliPortant than the two last, will for several rea- ,e bere treated with more fullness.16 Not one of gQle gi'er animals can be named which does not bear ^Jue ptnt jn a rudimentary condition ; and man forms be ?X<*eP^i°n to the rule. Eudimentary organs must in C S^lnSuished from those that are nascent ; though areS°me cuse!S the distinction is not easy. The former n , eitber absolutely useless, such as the mammae of wk' a <lUadmPede, or the incisor teeth of ruminants gjj never cut through the gums; or they are of such su° 1 Ser'bce to their present possessors, that we cannot P°se that they were developed under the conditions
16 (pi "
K ‘ Mnn’*’ n ' Hist.’ Boston, 1863, vol. ix. p. 185.
18 IiLdS P a0eil1 Nature,’ p. 65.
able paper a rounb copy of this chapter before reading a vala-
Annuario n‘(limenlali in ordine all’ origins del uomo ”
to which, pav,,! t "t- Hat.,’ Modena, 1867, p. 81), by Gr. Canes trini,
fable discuss!' f . RIn colltiiHornbly indebted. Hiicltel lias given admi- tn bia • (jene “s on tins whole subject, under the title of Dystelcology, Yq. , e e Morphologic’ and 1 Schopfungsgeschiehte.’
18
THE DESCENT OP MAN.
Part I.
which now exist. Organs in this latter state are not strictly rudimentary, hut they are tending in this direc- tion. Nascent organs, on the other hand, though not fully developed, are of high service to their possessors, and are capable of further development. Rudimentary organs are eminently variable; and this is partly in- telligible, as they are useless or nearly useless, and consequently are no longer subjected to natural selec- tion. They often become wholly suppressed. When this occurs, they are nevertheless liable to occasional reappearance through reversion ; and this is a circum- stance well worthy of attention.
Disuse at that period of life, when an organ is chiefly used, and this is generally during maturity, together with inheritance at a corresponding period of life, seem to have been the chief agents in causing organs to be- come rudimentary. The term “ disuse ” does not relate merely to the lessened action of muscles, but includes a diminished flow of blood to a part or organ, from being subjected to fewer alternations of pressure, or fiom becoming in any way less habitually active. Rudi- ments, however, may occur in one sex of parts normally present in the other sex ; and such rudiments, as we shall hereafter see, have often originated in a distinct manner. In some cases organs have been reduced by means of natural selection, from having become inju- rious to the species under changed habits of life. The process of reduction is probably often aided through the two principles of compensation and economy of growth ; but the later stages of reduction, after disuse has done all that can fairly be attributed to it, and when the saviwr to be effected by the economy of growth would be very small,19 are difficult to understand. The final and com-
10 Some good criticisms on this subject have been given by Messrs. Muric and Mivnrt, in ‘ Transact. Zoolog. Soc.’ 1869, vol. vii. p. 92.
ClUp. I,
KUDIMENTS.
19
j?e|fe ®UPPr®ss^on °f a part, already useless and much eco 1Cet IU 8*Ze’ ™ wb*cb case neither compensation nor tileQ°®y can come into play, is perhaps intelligible by in aU 1°* ^ie hypothesis °i' pangenesis, and apparently tarv° ° Gr " a'r‘ b'ut as the whole subject of rudimen- ;n y 01’gans has been fully discussed ' and illustrated 1‘eirP lormer woriiS/° I need here say no more on this
^Rudiments of various muscles have been observed in wh'1.! ^aitS ^ie human b°dy > 21 aild not a few muscles, are regularly present in some of the lower ani- red ^ C^n occasiouaUy be detected in man in a greatly .)()JlCe cpndition. Every one must have noticed the of m1 • cb nrany animals, especially horses, possess jjV 0Vlng or twitching their skin ; and this is effected in an^ i'aunb'ubls carnosus. Remnants of this muscle bodin ! state are found in various parts of our
’ r or instance, on the forehead, by which the devel 'JU S| U'e ra'se<b d’lic flaiysma myoides, which is well Turn 0Pe •°U ne,jb> belongs to this system. Prof, inform^ ° hdinljurgh, has occasionally detected, as he tion ■ S Uie’ UlUscular fasciculi in five different situa- whichname ^ 'n ^1C axdla‘) near the scapulae, &c., all of He h' IQ,jSt 'J0 reterred to the system of the panniculus. Kalis T a S° sbe" n 22 ^at the musculus sternalis or ster- dljcio ni/orum’ which is not an extension of the rectus minalis, but is closely allied to the panniculus, oc-
20 < ~tr .
PP. 317 and 39 7 of and Plants under Domestication,’ vol. ii.
21 For install . m also ‘ 0rl&111 of Species,’ Stir edit. p. 535.
Zoolog. 1S52 t 6 .tUohftrd (‘ Aunales des Sciences Nat.’ 3rd series, 116 calls the’“ l?' P' deseribcs alul figures rudiments of wliat " ‘“fiuiment neti,n 6 P*lieux tle ,a main •” which he says is sometimes generally quite / Another muscle, called “le tibial posterieur,” is ft0,re or less rudim, m the lland’ but aPPears from time to time in a
Prof, w t ‘ary c0111111'""-
uiiur, ‘Proe. Xtoyal Soc. Edinburgh,’ 1866-67, p. 65.
20
THE DESCENT OF MAN.
Tart I.
curred in the proportion of about 3 per cent, in upwards of 600 bodies : lie adds, that this muscle affords “ an “ excellent illustration of the statement that occasional “ and rudimentary structures are especially liable to “ variation in arrangement.”
Some few persons have the power of contracting the superficial muscles on their scalps ; and these muscles are in a variable and partially rudimentary condition. M. A. de Candolle has communicated to me a curious instance of the 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 a 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 all his three chil- dren possess the same power to the same unusual degree. This family became divided eight generations ago into two branches ; so that the head of the above-mentioned branch is cousin in the seventh degree to the head of the other 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 persistently an absolutely useless faculty may be transmitted.
The extrinsic muscles which serve to move the whole external ear, and the intrinsic muscles which move the different parts, all of which belong to the system of the panniculus, are in a rudimentary condition in man ; they are also variable in development, or at least in function. I have seen one man who could draw his ears for- wards, and another wdio could draw them backwards;23
23 Canestrini quotes Hyrt. (‘ Annuario della Soc. dei Naturalisti,’ Modena, 1867, p. 97) to the same effect.
Chap. i.
RUDIMENTS.
21
b\i^r°m w^la^ orie these persons told me, it is pro- a J e that most ot us by often touching our ears and Us Erecting our attention towards them, could by repeated trials recover some power of movement. The acuity of erecting the ears and of directing them to I 'ncrent points of the compass, is no doubt of the ughest service to many animals, as they thus perceive le l)0*ut of danger; but I have never heard of a man '' l0 Possessed the least power of erecting his ears, — le one movement which might be of use to him. The W lc^e external shell of the ear may be considered a rudiment, together with the various folds and promi- nences (helix and anti-helix, tragus and anti-tragus, &c.) ' ich in the lower animals strengthen and support the ^ar "hen erect, without adding much to its weight. ^ orue authors, however, suppose that the cartilage of the serves to transmit vibrations to the acoustic k'erve > but Mr. Toynbee,'44 after collecting all the 'flown evidence on this head, concludes that the exter- 1 SlePl 48 °f uo distinct use. The ears of the chim- panzee and orang are curiously like those of man, and I th ,dS,Sured by the keepers in the Zoological Gardens tjjdt ^bese animals never move or erect them ; so that ^ ^ are m an equally rudimentary condition, as far as asUctl0Q 48 concerned, as in man. Why these animals, We 1 as the progenitors of man, should have lost the wei of erecting their ears we cannot say. Jt may be, 1 b am not quite satisfied with this view, that owing hut r'"U' ai'bQ1'(-al habits and great strength they were Per' V 6 <!Xb°sed to danger, and so during a lengthened l0 , '°,1 rnoved their ears hut little, and thus gradually rnrnii P°Wer of moving them. This would be a d e Case with that of those large and heavy birds,
The Diseases of the Ear,’ by J. Toynbee, F.R.S., I860, p. 12.
22
THE DESCENT OF MAN.
Part I.
■which from inhabiting oceanic islands have not been exposed to the attacks of beasts of prey, and have con- sequently lost the power of using their wings for flight.
The celebrated sculptor, Mr. Woolner, informs me of one little peculiarity in the external ear, which he has often observed both in men and women, and of which he perceived the full signification. His attention was first called to the subject whilst at w ork on his figure of Puck, to which he had given pointed ears. He was thus led to examine the ears of various monkeys, and subsequently more carefully those of man. The pecu- liarity consists in a little blunt point, projecting from the inwardly folded margin, or helix. Mr. Woolner made an exact model of one such case, and has sent
trifling a character to be worth notice. This thought, however, is as false as it is natural. Every character, however slight, must be the result of some definite cause ; and if it occurs in many individuals deserves consideration. The helix obviously consists of the ex- treme margin of the ear folded inwards ; and this fold- ing appears to be in some manner connected with the
me the accompanying drawing. (Fig. 2.) These points not only project inwards, but often a little
Fig. 2. Human Ear, modelled and drawn by Mr. Woolner. a. The projecting point.
a outwards, so that they are visible when the head is viewed from di- rectly in front or behind. Thev * *
are variable in size and some- what in position, standing either a little higher or lower; and they sometimes occur on one ear and not on the other. Now the mean- 1 ing of these projections is not, I think, doubtful; but it may be thought that they offer too
Chap. j.
RUDIMENTS.
23
10 e external ear being permanently pressed back- ,au S- many monkeys, which do not stand high in 16 01 ^Gr» as baboons and some species of macaeus,25 the lPpei portion of the ear is slightly pointed, and the Margin js not at all folded inwards ; but if the margin "'ere to be thus folded, a slight point would necessarily Project inwards and probably a little outwards. This con hi actually be observed in a specimen of the A ides eelzebuth in the Zoological Gardens ; and we may safely conclude that it is a similar structure — a vestige of ^oirnerly pointed ears — which occasionally reappears in
^>e nictitating membrane, or third eyelid, with its nccessory muscles and other structures, is especially VVe developed in birds, and is ol much functional im- portance to them, as it can be rapidly drawn across the " o e eye-ball. It is found in some reptiles and arnphi- and in certain fishes, as in sharks. It is fairly e developed in the two lower divisions of the mam- noi ian series, namely, in the monotremata and marsu- 1 la s, and in some few of the higher mammals, as in the 'a rus‘ '’Of in man, the quadrumana, and most other lammals, it exists, as is admitted by all anatomists, as a rue re rudiment, called the semilunar fold.20
the 16 S6nSe SIII<dl is of the highest importance to greater number of mammals — to some, as the rumi- nants, in warning them of danger ; to others, as the
23
roidea m S°me remal'ks, and the drawings of the ears of the Lemu- ZooW ‘easrs- Murie and Mivart’s excellent paper in 1 Transact.
26 MuilerW,”1 18G9’ rp' G and 90‘
1117. 0 ^lements of Physiology,’ Eng. translat., 1842, vol. ii. p. Walrus ‘p, ■Unatori:|y of Vertebrates,’ vol. iii. p. 2<J0; ibid. on the ' Great Artist-' Soc-’ November 8th, 1854. See also E. Knox,
wrnewhat lar* aUd.',^na^om^s^s’' P- 10G. This rudiment apparently is V°gt, ‘ I m qcSroes and Australians than in Europeans, see Carl
es 011 Man,’ Eng. translat. p. 129.
21
THE DESCENT OF MAN.
Part I.
carnivora, in finding tlieir prey ; to others, as the wild boar, for both purposes combined. But the sense of smell is of extremely slight service, if any, even to savages, in whom it is generally more highly developed than in the civilised races. It does not warn them of danger, nor guide them to their food; nor does it pre- vent the Esquimaux from sleeping in the most fetid atmosphere, nor many savages from eating half-putrid meat. Those who believe in the principle of gradual evolution, will not readily admit that this sense in its present state was originally acquired by man, as he now exists. No doubt he inherits the power in an enfeebled and so far rudimentary condition, from some early progenitor, to whom it was highly serviceable and by whom it was continually used. We can thus perhaps understand how it is, as Dr. Maudsley has trulv remarked,27 that the sense of smell in man “ is singu- “ Drly effective in recalling vividly the ideas and images '• of forgotten scenes and places for we see in those animals, which have this sense highly developed, such as dogs and horses, that old recollections of persons and places are strongly associated with their odour.
Man differs conspicuously from all the other Primates in being almost naked. But a few short straggling hairs are found over the greater part of the body in the male sex, and fine down on that of the female sex. In individuals belonging to the same race these hairs are highly variable, not only in abundance, but like- wise in position : thus the shoulders in some Europeans are quite naked, whilst in others they bear thick tufts of hair.28 There can be little doubt that the hairs
21 ‘ The Physiology and Pathology of Mind,’ 2nd edit. 1868, p. 134.
28 Eschricht, Ueber die Richtung dev Huare am mensehlichen Kdrper, ‘ Muller's Archtv fur Auat. und Phvs.’ 1837, s. 47. I shall often have to refer to tills very curious paper.
(-'hap I.
RUDIMENTS.
25
thus
scattered over the body are the rudiments of the
Uuiform hairy coat of the lower animals. This view is gendered all the more probable, as it is known that fine, 10rb aild pale-coloured hairs on the limbs aud other I’Hrts of the body occasionally become developed into iickset, long, and rather coarse dark hairs,” when ab- nor maHy nourished near old-standing inflamed surfaces.29 ^ f am informed by Mr. Paget that persons belonging 0 the same family often have a few hairs in their eye- J1°ws much longer than the others: so that this slight Peculiarity seems to be inherited. These hairs appa- rently represent the vibrissa:, which are used as organs
0 tonch by many of the lower animals. In a young j '|mpanzee I observed that a few upright, rather long,
ail-s, projected above the eyes, where the true eyebrows,
1 present, would have stood.
. e fine wool-like hair, or so-called lanugo, with rch the human foetus during the sixth month is . llckly covered, offers a more curious case. It is first y vdoped, during the fifth month, on the eyebrows and ,iee, and especial])' round the mouth, where it is much ( l,lger than that on the head. A moustache of this kind 'Vlls observed by Eschricht30 on a female foetus ; but this n°t so surprising a circumstance as it may at first ap- PjfU, ^°r the two sexes generally resemble each other in Tli eXt.erna* characters during an early period of growth, of *1 <lire<'tiou and arrangement of the hairs on all parts _le toetal body are the same as in Ike adult, but are U to a inch variability. The whole surface, including
-'eti the forehead and ears, is thus thickly clothed ; but Js a significant fact that the palms of the hands and surf-S°^eS ^le feet are quite naked, like the inferior aces of all four extremities in most of the lower
l ■p< ,
! p'* , ! ‘lectures on Surgical Pathology,’ 1S53, vol. i. p. 71.
Eschricht, ibid. s. 40, 47?
26
THE DESCENT OF MAN.
Part I.
animals. As this can hardly be an accidental coinci- dence, we must consider the woolly covering of the foetus to be the rudimental representative of the first permanent coat of hair in those mammals which are born hairy. This representation is much more com- plete, in accordance with the usual law of etnbryological development, than that afforded by the straggling hairs on the body of the adult.
It appears as if the posterior molar or wisdom-teeth were tending to become rudimentary in the more civi- lised races of man. These teeth are rather smaller than the other molars, as is likewise the case with the corresponding teeth in the chimpanzee and orang ; and they have only two separate fangs. They do not cut through the gums till about the seventeenth year, and I have been assured that they are much more liable to decay and are earlier lost than the other teeth ; but this is denied by some dentists. They are also much more liable to vary both in structure and in the period of their development than the other teeth.31 In the Melanian races, on the other hand, the wisdom-teeth are usually furnished with three separate fangs, and are generally sound : they also differ from the other molars in size less than in the Caucasian races.32 -Prof. Schaaff hausen accounts for this difference between the races by “ the posterior dental portion of the jaw bein«r “always shortened” iu those that are civilised,33 and this shortening may, 1 presume, be safely attributed to civi- lised men habitually feeding on soft, cooked food, and thus using their jaws less. I am informed by Mr. Brace that it is becoming quite a common practice in the United
W Te®th 111 Man a,ld tlie Anthropoid Apes,’ as quoted by Dr. C. Carter Blake in ‘ Anthropological Review,’ July, 1867, p. 299.
“ Owen, * Anatomy of Vertebrates,’ vol. iii. pp. 320, 321, and 325 33 1 On tire Primitive Form of the Skull,’ Eng. translat. in ‘ Anthro- pological Jieviow,’ Oct. 1808, p. 426.
Chap. i.
RUDIMENTS.
27
ates to remove some of the molar teeth of children, !|S ^le Jaw does not grow large enough for the perfect c e' elopment of the normal number.
Vith respect to the alimentary canal I have met
I 1 an account of only a single rudiment, namely the 'eimiform appendage of the ceecum. The caecum is a branch or diverticulum of the intestine, ending in a
‘-ue-siic, and it is extremely long in many of the .°Wer vegetable-feeding mammals. In the marsupial '"ala it is actually more than thrice as long as the '°le body.34 It is sometimes produced into a long Sradually-tapering point, and is sometimes constricted Pai'ts. It appears as if, in consequence of changed . °y habits, the cmcum had become much shortene l 'arious animals, the vermiform appendage being left a rudiment of the shortened part. That this ap-
II m age is a rudiment, we may infer from its small -»-d from the evidence which Prof. Canestrini 36 has
ected of its variability in man. It is occasionally j * e ahsent, or again is largely developed. The passage sometimes completely closed for half or two-thirds of 8 ®ngth> with tlie terminal part consisting of a flat- solid expansion. In the orang this appendage in man it arises from the and is commonly from four being only about the third - . — — Not only is it useless, but
sometimes the cause of death, of which fact I hard !atdy ^lear<l two instances: this is due to small < Jodies, such as seeds, entering the passage and
causing inflammation »
S on§ and convoluted .
*he short case urn, ?, VQ_ inches in length, au inch in diameter.
3f
31 i -faatoray of Vertebrates,’ vol. iii. pp. 416, 434, 441.
»» n c dell!l Soo. d. Nat.’ Modena, 1867, p. 94. blondes ’ Jon ai,*‘ns (“Do l’Unite Organiquc,” in ‘Revue des Deux e , 1862, p. 1G), and Hackel (‘Generelle Morphologie,'
28
THE DESCENT OP MAN.
Part t
In some of the Quadrumana, in the Lemuridse, and especially in the Carnivora, there is a passage near the lower end of the humerus, called the supra-condvloid foramen, through which the great nerve of the fore limb passes, and often the great artery. Now in the humerus ot man, as Dr. Struthers37 and others have shewn, there is generally a trace of this passage, and it is sometimes fairly well developed, being formed by a depending hook-like process of bone, completed by a band of ligament. When present the great nerve invariably passes through it, and this clearly indicates that it is the homologue and rudiment of the supra-condyloid fora- men of the lower animals. Prof. Turner estimates, as he informs me, that it occurs in about one per cent ot recent skeletons. But this case does not possess much interest, as the foramen is not regularly present in the higher Quadrumana. It is therefore doubtful, as Mr. Busk has remarked to me, whether its occasional presence in man can be attributed to the retension or reversion ot a primordial structure.
There is another foramen in the humerus, which may be called the inter-condyloid. This occurs in various anthiopoid and other apes,38 but likewise in many of the towel animals, and occasionally in man. It is remarkable that this foramen seems to have been much more fre- quently present during ancient than during recent times. Mr. Busk 39 has collected the following evidence on this head : Prof. Broca “ noticed the perforation in four and a
B. ii. s. 278), have both remarked on the singular fact of this rudiment sometimes causing death.
37 ‘ The Lancet,’ Jan. 24, 18(13, p. 83. Dr. Knox, • Great Artists and
Anatomists,, p. (13. See also an important memoir on this process by Dr. Grube, in the ‘ Bulletin de 1’Acad. Imp. de St. Petersbour^ ’ tom. xn, 1867, p. 448. D’
38 Mr. St. George Mivart, ‘Transact. Phil. Soc.’ 1867, p. 310.
39 “ On the Caves of Gibraltar,” * Transact. Intermit. Congress of Prehist. Arch.’ Third Session, 1869, p. 159.
Chap. i.
RUDIMENTS.
29
((U' Per “ cent, of the arm-bones collected in the ‘ Cime- « ieie c^u Sud ’ at Paris ; and in the Grotto of Orrony, the „ COatents of which are referred to the Bronze period, ,ls many as eight humeri out of thirty-two were perfo- rated; but this extraordinary proportion, he thinks, (( aaght be due to the cavern having been a sort of (f |;lIni!y vault.’ Again, M. Dupont found 30 per cent. t( 0 perforated bones in the caves of the Yallcy of the <t :res8e> belonging to the Reindeer period ; whilst M.
jeguay, in a sort of dolmen at Argenteuil, observed [( ^venty-five per cent, to be perforated ; and M. Pruner- <( . °y found twenty-six per cent, in the same condition (1 lri bones from Y aureal. N or should it be left unno- „ tleec^ that M. Pruncr-Bcy states that this condition is common in Guanche skeletons.” The fact that ancient aees> hr this and several other cases, more frequently present structures which resemble those of the lower ammals than do the modern races, is interesting. One j1Ca cause seems to be that ancient races stand some- j lftt nearer than modern races in the long lino of, * to fbeir remote animal-like progenitors.
■ • iC 08 coccyx ™ man, though functionless as a tail, mun y represents this part in other vertebrate animals.
an early embryonic period it is free, and, as we have j^1'5 P10iects beyond the lower extremities. In certain aie and anomalous cases it has been known, according ^ snlore Geoftroy St.-Hilaire and others,40 to form a external rudiment of a tail. The os coccyx is r. ’ nsually including only four vertebrae : and these ° m a ru<fimental condition, for they consist, with the areT l0-U basal one, of the centrum alone.41 They j C Urnished with some small muscles ; one of which as am informed by Prof. Turner, has been expressly
‘ Revue nSeS 11 as collected the evidence on this subject.
41 Owen ^.Seientifi^s/ 18G7-18(JS, p. 025.
> t u the Nature of Limbs,’ 1849, p. 114.
30
THE DESCENT OF MAN.
Part I.
described by Theile as a rudimentary repetition of the extensor of the tail, which is so largely developed in many mammals.
The spinal cord in man extends only as far down- wards as the last dorsal or first lumbar vertebra; but a thread-like structure (the filum terminate) runs down the axis of the sacral part of the spinal canal, and even along the back of the coccygeal bones. The upper part of this filament, as Prof. Turner informs me, is undoubtedly homologous with the spinal cord ; but the lower part apparently consists merely of the j)ia mater, or vascular investing membrane. Even in this case the os coccyx may be said to possess a vestige of so im- portant a structure as the spinal cord, though no longer enclosed within a bony canal. The following fact, for which I am also indebted to Prof. Turner, shews how closely the os coccyx corresponds with the true tail in the lower animals: Luschka has recently discovered at the extremity of the coccygeal bones a very peculiar convoluted body, which is continuous with the middle sacral artery ; and this discovery led Krause and Meyer to examine the tail of a monkey (Macacus) and of a cat, in both of which they found, though not at the extre- mity, a similarly convoluted body.
The reproductive system oilers various rudimentary structures ; but these differ in one important respect from the foregoing cases. We are not here concerned with a vestige of a part which does not belong to the species in an efficient state ; but with a part which is always present and efficient in the one sex, beinn represented in the other by a mere rudiment. Never- theless, the occurrence of such rudiments is as diffi- cult to explain on the belief of the separate creation of each species, as in the foregoing cases. Hereafter I shall have to recur to these rudiments, and shall shew that their presence generally depends merely on
CilAP, I.
THE DESCENT OE MAN.
31
ha ei^ance > namely, on parts acquired by one sex }Xen Partia% transmitted to the other. Here is '! 11.0nlJr give s°me instances of such rudiments. It clud"3 ^novvn that in the males of all mammals, in- S( . ln§ nmn, rudimentary mammas exist. These in vi'lDi lnstances have become well developed, and have tit • a cof,ious suPP]y milk. Their essential iden- y nr the two sexes is likewise shewn by their occa- atf sympathctic enlargement in both during an ha-sl °f the measles. The vesicula prostatica, which een observed in many male mammals, is now uni- ^eisally acknowledged to be the liomologuc of the jgftla e nterus, together with the connected passage. It J^-ble to read Leuckart’s able description of this 0f\an> ant* bis reasoning, without admitting the justness tho ^ concbision. This is especially clear in the case of cates DJam“als in which the true female uterus bifur- h>it'ivr 5 01 JU tb*3 males of these the vesicula likewise bel 1CatGS'42 ^°me additional rudimentary structures u. n>=lno to the reproductive system might here have een adduced.43
e. bearing of the three great classes of facts now full ^ 1S UnniIstakeable. But it would be superfluous here in I le*'aIatulrtte the line of argument given in detail of the °b Species.’ The homological construction
inteir "i'l0^e frame in the members of the same class is pr S'ole, if we admit their descent from a common to togetbe.r with their subsequent adaptation
larit 1Ve,rsb‘ec^ conditions. On any other view the simi- 3" o pattern between the hand of a man or monkey,
hx la«rtt!Srt’rl“TT,?dd’s,‘ Cyclop. of Aliat:’ 1849'52> iv- [>. Min. "1 ttany other i ' '
this • - i r - — — • -
80 many other ru p 13 0n,y from tbree to six lines in length, but, like 88 'a other char (,!mentary parts, it is variable in development as well See ■ a"
(176, 7QQtlds subject, Owen, ‘Anatomy of Vertebrates,’ vol.
iii. pp.
32
THE DESCENT OF MAN.
Fart I-
the foot of a horse, the flipper of a seal, the wing of a bat, &c., is utterly inexplicable. It is no scientific explanation to assert that they have all been formed on the same ideal plan. With respect to development, we can clearly understand, on the principle of varia- tions supervening at a rather late embryonic period, and being inherited at a corresponding period, how it is that the embryos of wonderfully different forms should still retain, more or less perfectly, the structure of their common progenitor. No other explanation has ever been given of the marvellous fact that the embryo of a man, dog, seal, bat, reptile, &c., can at first hardly be distinguished from each other. In order to understand the existeirce of rudimentary organs, we have only to suppose that a former progenitor possessed the parts in question in a perfect state, and that under changed habits of life they became greatly reduced, either from simple disuse, or through the natural selection of those indivi- duals which were least encumbered with a superfluous part, aided by the other means previously indicated.
Thus we can understand how it has come to pass that man and all other vertebrate animals have been constructed on the same general model, why they pass through the same early stages of development, and why they retain certain rudiments in common. Consequently we ought frankly to admit their community of descent: to take any other view, is to admit that our own struc- ture and that of all the animals around us, is a mere snare laid to entrap our judgment. This conclusion is greatly strengthened, if we look to the members of the whole animal series, and consider the evidence de- rived from their affinities or classification, their geo- graphical distribution and geological succession. It is only our natural prejudice, and that arrogance which made our forefathers declare that they were descended from demi-gods, which leads us to demur to
Cijip j
THE DESCENT OF MAN.
33
ls conclusion. But the time will before long come ^ len it will be thought wonderful, that naturalists, who "ere Well acquainted with the comparative structure j n< development of man and other mammals, should d'e believed that each was the work of a separate act
of
creation.
D
VOT,. x.
34
THE DESCENT OF MAN.
Part t.
CHAPTER II.
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 — Ima- gination — Reason — Progressive improvement — Tools and weapons used by animals — Language — Self-consciousness — Sense of beauty — Belief in God, spiritual agencies, superstitions.
We have seen in the last chapter 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 com- pare the mind of one of the lowest savages, who has no words to express any number higher than four, and who uses no abstract terms for the commonest objects or affections,1 with that of the most highly organised ape. The difference would, no doubt, still remain immense, even if one of the higher apes had been improved or civilised as much as a dog has been in comparison with its parent-form, the wolf or jackal. The Fuegians rank amongst the lowest barbarians ; but I was continually struck with surprise how closely the three natives on hoard 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
1 See the evidence on those points, as given by Lubbock, 1 Prehistoric Times,’ p. 354, &c.
'Ciup. jjr
MENTAL POWEES.
35
01 game being excepting man liacl possessed any mental power, or if his powers had been of a wholly different Mature from those of the lower animals, then we should jUfVer have been able to convince ourselves that our "&b faculties had been gradually developed. But it on be clearly shewn that there is no fundamental f ifference of this kind. We must also admit that lore is a much wider interval in mental power be- eeu one of the lowest fishes, as a lamprey or lancelct, °no of the higher apes, than between an ape and fan; yet this immense interval is filled up by ntimber- Iess gradations.
Nor
is
, - — the difference slight in moral disposition
etween a barbarian, such as the man described by the ? navigator Byron, who dashed his child on the rocks p1 dropping a basket of sea-urchins, and a Howard or arkson ; and in intellect, between a savage who does Trf U8e an^ akstraet terms, and a Newton or Shakspeare. ^ 1 ferences of this kind between the highest men of the J1ghest races and the lowest savages, are connected by 10 ®uest gradations. Therefore it is possible that they nnght pass and be developed into each other.
. Ny object in this chapter is solely to shew that there jS. 110 fundamental difference between man and the b- ier mammals in their mental faculties. Each divi- ■ *°n ot the subject might have been extended into a ^ate essay, but must here be treated briefly. As ^ classification of the mental powers has been univer- “ y accepted, I shall arrange my remarks in the order p convenient for my purpose ; and will select those tlm S fi&ve most struck me, with the hope that
Produce some effect on the reader, hav + 1 r?sfiect to animals very low in the scale, I shall lion6 1° ^-'*e some additional facts under Sexual Selec- ’ s 10wing that their mental powers are higher than
d 2
3G
THE DESCENT OF MAN.
Part P.
might have been expected. The variability of the facul- ties in the individuals of the same species is an im- portant point for ns, and some few illustrations will here be given. But it would be superfluous to enter into many details on this head, for I have found on frequent enquiry, that it is the unanimous opinion of all those who have long attended to animals of many kinds, including birds, that the individuals differ greatly in every mental characteristic. In what manner the mental powers were first developed in the lowest organisms, is as hopeless an enquiry as how life first originated. These are problems for the distant future, if they are ever to be solved by man.
As man possesses the same senses with 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 power possessed by the latter of sucking, and so forth. But man, perhaps, has somewhat fewer instincts than those possessed by the animals which come next to him in the scries. The orang in the Eastern islands, and the chimpanzee in Africa, build platforms on which they sleep ; and, as both species follow the same habit, it might he argued that this w as due to instinct, but we cannot feel sure that it is not the result of both animals having similar wants and possessing similar powers of reasoning. These apes, as wc may assume, avoid the many poisonous fruits of the tropics, and man has no such knowledge ; but as our domestic animals, when taken to foreign lands and when first turned out in the spring, often eat poisonous herbs, which they afterwards avoid, wo 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
MENTAL POWERS.
■7
C"AP. II.
au instinctive clread of serpents, and probably of other dangerous animals.
. i he fewness and the comparative simplicity of the '"stincts in the higher animals are remarkable in eon- trast with those of the lower animals. Cuvier main- tained that instinct and intelligence stand in an inverse oitio to each other; and some have thought that the intellectual faculties of the higher animals have been fdadually developed from their instincts. .But Pouch et, 111 an interesting essay,3 has shewn that no such inverse latio really exists. Those insects which possess the most n'onderful instincts are certainly the most intelligent.
' u the vertebrate series, the least intelligent members, finely fishes and amphibians, do not possess complex instincts ; and amongst mammals the animal most re- f-nirkable for its instincts, namely the beaver, is highly mtelligent, as will be admitted by every one who has lea<t Mr. Morgan’s excellent account of this animal.3 . Although the first dawnings of intelligence, accord- to Mr. Herbert Spencer,4 have been developed H'ough the multiplication and co-ordination of reflex aetions, and although many of the simpler instincts fdaduate into actions of this kind and can hardly be r lstinguished from them, as in the case of young animals Peking, yct t]10 more complex instincts seem to liave ^'giuated independently of intelligence. I am, how- ever> Mr from wishing to deny that instinctive actions illuy lose their fixed and untaught character, and he ■j -'placed by others performed by the aid of the free will, j ,n ^he other hand, some intelligent actions — as when ,|Jds on oceanic islands first learn to avoid man — after
3, 97,-. ^llstiuot eliez les Insectes.’ ‘Revue des Deux Mondes,’ Feb. P- 690.
4 ‘ T)16 American Beaver and Ms Works,’ 1868.
le Principles of Psychology/ '2nd edit. 1870, pp. 416-443
38
THE DESCENT OF MAN.
Pari I.
being performed during many generations, become con- verted into instincts and are inherited. They may then bo 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 man- ner, through the natural selection of variations of simpler instinctive actions. Such variations appear to arise from the same unknown causes acting on the cerebral organ- isation, which induce slight variations or individual dif- ferences in other parts of the body ; and these variations, owing to our ignorance, are often said to arise sponta- neously. We can, I think, come to no other conclusion with respect to the origin of the more complex instincts, when we reflect on the marvellous instincts of sterile worker-ants and bees, which, leave no offspring to inherit the effects of experience and of modified habits.
Although a high degree of intelligence is certainly compatible with the existence of complex instincts, as we see in the insects just named and in the beaver, it is not improbable that they may to a certain extent inter- fere with each other’s development. Little is known about the functions ol the brain, but we can perceive that as the intellectual powers become highly developed, the various parts of the brain must be connected by the most intricate channels of intercommunication ; and as a consequence each separate part would perhaps tend to become less well fitted to answer in a definite and uni- form, that is instinctive, manner to particular sensations or associations.
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 com- pare their actions founded on the memory of past events, on foresight, reason, and imagination, with
MENTAL POWEES.
3!)
ttij
«*. II.
■'xactly similar actions instinctively performed by the °'Ver animals ; in this latter case the capacity of Informing such actions having been gained, step by s^ePi through the variability of the mental organs and Natural selection, without any conscious intelligence on 16 part of the animal during each successive genera- 10u- No doubt, as Mr. Wallace has argued,6 much of kl° intelligent work done by man is due to imitation and to reason ; but there is this great difference between Us_ actions and many of those performed by the lower aDimals, namely, that man cannot, on his first trial, !nake, for instance, a stone hatchet or a canoe, through ns power of imitation. He has to learn his work by Practice ; a beaver, on the other hand, can make its dam I*1 canal, and a bird its nest, as well, or nearly as well, e first time it tries, as when old and experienced.
-i° return to our immediate subject: the lower animals, like man, manifestly feel pleasure and pain, happiness and misery. Happiness is never better exhi- bit'd than by young animals, such as puppies, kittens,
Ev
's> &c., when playing together, like our own children. ,Veu insects play together, as has been described by dt excellent observer, P. Huber,0 who saw ants chasing aild pretending to bite each othei-, like so many puppies.
Ihe fact that the lower animals are excited by the same emotions as ourselves is so well established, that J 'nil not he necessary to weary the reader by many c et?dls. Terror acts in the same manner on them as on causing the muscles to tremble, the heart to pal- pitate, the sphincters to be relaxed, and the hair to and on end. Suspicion, the offspring of fear, is emi- Jaently characteristic of most wild animals. Courage
0 .^Mmtions to the Theory of Natural Selection,’ 1870, p. 212. •Keoherches snr les Mceurs des Fourmis,’ 1810, p. 173.
40
THE DESCENT OF MAN.
Part I.
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-tempered and easily turn sulky ; others are good-tempered ; and these qualities are certainly inherited. Every oue knows liow liable animals arc to furious rage, and how plainly they show it. Many anecdotes, probably true, have been published on the long-delayed and artful revenge of various animals. The accurate Eengger and Erehm7 state that the American and African monkeys which they kept tame, certainly revenged themselves, llie love of a dog tor his master is notorious; in the agony ol death ho has been known to caress bis master, and every one has heard of the dog suffering under vivisection, who licked the hand of the operator; this man, unless ho had a heart ol stone, must have felt remorse to the last hour of his life. As Whewell8 has remarked, “ 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 Eengger observed an American monkey (a Cebus) carefully driving away the flies which plagued her infant; and Duvaucel saw a llylobates washing the faces of her young ones iu a stream. So intense is the grief of female monkeys for the loss of their young, that it invariably caused the death of cer- tain kinds kept under confinement by Brehm in N.
' All tlie following statements, given on the authority of those two naturalists, arc taken from Rengger’s ‘ Naturges. tier Saugetkiere vou Paraguay,’ 1830, s. 41-57, and from Brehm’s ‘ Thierleben ’ B i s. 10-87.
8 ‘ Bridgewater Treatise,’ p. 203.
'■'•Ur. u.
MENTAL POWERS.
41
■ hica. Orphan- monkeys were always adopted and °ai'efully guarded by the other monkeys, both males a,1d females. One female baboon had so capacious a "'art that she not only adopted young monkeys of Ie|' species, but stole young dogs and cats, which she “’"tinually carried about. Her kindness, however, did "'f go so far as to share her food with her adopted ""spring, at which Brehm was surprised, as his monkeys 1 wa.vs divided everything quite fairly with their own •UUng ones. An adopted kitten scratched the above- mentioned affectionate baboon, who certainly had a intellect, for she was much astonished at being hatched, and immediately examined the kitten’s feet, y" without more ado bit off the claws. In the /0o ogical Gardens, 1 heard from the keeper that 111 old baboon (G. cliacma ) had adopted a Rhesus °nkey . )Jut wpen a young drill and mandrill were
d, ed in ppe ca„e sj10 seeined to perceive that these monke
P C:S’ tor she at once rejected the Rhesus and adopted dp, 1 tfienr. The young Rhesus, as I saw, was greatly ' ""tented at being thus rejected, and it would, like
tiy Ve^8> tllough distinct species, were her nearer rela-
C
di;
flighty child, annoy and attack the young drill and ^aiidrill whenever it could do so with safety; this ^r1'1 Uct exciting great indignation in the old baboon.
011 will also, according to Brehm, detcud their vaster when attacked by any" one, as well as dogs to I 0111 they are attached, from the attacks ot other tob5,‘, . Iiut we here trench on the subject of sympathy, fool-11 ^ s*iah- recur. Some of Brelnu’s monkeys lv Inuch delight in teasing, in various ingenious
\YQjVo O
■ ’ a certain old doo- whom they disliked, as well as "ther animals.
tin* ]JS- ^le 111 ore complex emotions are common to ugher animals and ourselves. Every one has seen
42
THE DESCENT OF MAN.
Part I-
how jealous a dog is of his master’s affection, if lavished on any other creature ; and I have observed the same fact with monkeys. This shews that animals not only love, but have the 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 doubt that a dog feels shame, as distinct from fear, and something very like modesty when begging too often for food. A great dog scorns the snarling of a little dog, and this may be called magnanimity. Several observers have stated that monkeys certainly dislike being laughed at; and they sometimes invent imaginary offences. In the Zoological Gardens I saw a baboon who always got into a furious rage when his keeper took out a letter or book and read it aloud to him ; and his rage was so violent that, as I witnessed on one occasion, he bit his own leg till the blood flowed.
Wo will now turn to the more intellectual emotions and faculties, which are very important, as forming the basis for the development of the higher mental powers. Animals manifestly enjoy excitement and suffer from ennui, as may be seen with dogs, and, according to Rcngger, with monkeys. All animals feel Wonder, and many exhibit Curiosity. They sometimes suffer from tin's 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 towards snakes ; but their curiosity was so great that they could not desist from occasionally satiating their horror in a most human fashion, by lifting up the lid of the box in which the snakes were kept. I was so much surprised at his account, that I took a stuffed and
MENTAL POWERS.
43
Cha:
r. H.
^0l ed-up snake into the monkey -house at the Zoo- gieal Gardens, and the excitement thus caused was 2?e °f the most curious spectacles which I ever beheld.
-fhree
species of Oercopithecus were the most alarmed ;
. y dashed about their cages and uttered sharp signal- Cries of danger, which were understood by the other lll0nkeys. A few young monkeys and one old Anubis
babi
'°°u alone took no notice of the snake. I then
| aced the stuffed specimen on the ground in one of oe larger compartments. After a time all the monkeys ‘-'Elected round it in a large circle, and staring in- ently, presented a most ludicrous appearance. They became extremely nervous ; so that when a wooden ball,
1 1 1 which they were familiar as a plaything, was acci- Moved in the straw, under which it was partly i 1(. c en> they all instantly started away. These monkeys e laved very differently when a dead fish, a mouse, and mmo other new objects were placed in their cages ; for °ugh at first frightened, they soon approached, handled Uf examined them. I then placed a live snake in a ^ aPer bag, w ith the mouth loosely closed, in one of the 1 ger compartments. One of the monkeys immediately . I’fuoached, cautiously opened the bag a little, peeped p’ tlnc^ instantly dashed away. Then I witnessed what jj1'1'111 has described, for monkey after monkey, with raised high and turned on one side, could not at hddng momentary peeps into the upright bag, \v ^r°a<iful object lying quiet at the bottom. It z °l' d almost appear as if monkeys had some notion of neiogical affinities, for those kept by Brehm exhibited range, though mistaken, instinctive dread of inno- toT ^zarc^s and frogs. An orang, also, has been known e Much alarmed at the first sight of a turtle.3
*-'• L. Martin, ‘ Nat. Hist, of Mammalia,’ 1S41, p. 405.
THE DESCENT OF MAN.
rABi 1
44
4'lie piinciple of Imitation is strong' in man, and ■especially in man in a barbarous state. Desor 10 has remarked that no animal voluntarily imitates an action performed by man, until in the ascending scale we come to monkeys, which are well-known to be ridiculous mockers. Animals, however, sometimes imitate each ■others actions : thus two species of wolves, which had been reared by dogs, learned to bark, as does some- times the jackal,11 but whether this can be called volun- tary imitation is another question. From one account which I have read, there is reason to believe that puppies nursed by cats sometimes learn to lick their feet and thus to clean their bices : it is at least certain, as I hear from a perfectly trustworthy friend, that some dogs behave in this manner. Birds imitate the songs of their parents, and sometimes those of other birds; and par- rots are notorious imitators of any sound which they often hear.
Haidly any faculty is more important for the intel- lectual progress of man than the power of Attention ■ Animals clearly manifest this power, as when a cat watches by a hole and prepares to spring on its prey- W ild 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 iu monkeys. A man who trains monkeys to act used to purchase common kinds from the Zoological Society at the price of five pounds for each ; but he offered to give double the price, if he might keep three or four of them for a few days, in order to select one- \\ hen asked how lie could possibly so soon learn whether
“ l? Vo®t> ‘ Memoire sur les Microcepliales,' 1S67, p. 168.
1 he A ariation of Animals and Plants under Domestication,’ vol-
l. p. 2o
MENTAL POWERS.
45
Cu.
«\ II.
' Particular monkey would turn out a good actor, lie i- s"eiecl that it all depended on their power of atten-
cn- If when he was talking and explaining anything- a ni°nkey, its attention was easily distracted, as by
to
In ' i°n or other trifling object, the case was
peless. If ]ie tried by punishment to make an in- ] ontive monkey act, it turned sulky. On the other ' lir> a monkey which carefully attended to him could be trained.
18 almost superfluous to state that animals have at ti en^ Memories for persons and places. A baboon g. . e Cape of Good Hope, as I have been informed by ^^rew Smith, recognised him with joy after an aLd tlCe "*uo montbs. I had a dog who was savage men aVeiSC t0 !|P strangers, and I purposely tried his Went°1^ a^ei an absence of five years and two days. I him Ueur stable where he lived, and shouted to
b followed me out walking and obeyed me,
stantl'1 monnor > bo showed no joy, but in-
hefcn 'V aS ^ ^ bac^ parted with him only lmlf-an-hour year.^'i ^ train of old associations, dormant during five mf i ’ 1 , ^bus been instantaneously awakened in his I'ccoV . bbren ants, as 1’. Huber la has clearly shewn, m, °niSed their fellow-ants belonging to the same eom- Can 1 y after a separation of four months. Animals tir ?rtainly by some means judge of the intervals of
of
rpi 1UL4U1 tJJ-I li tJVtJLLlto.
10 Imagination is one of the highest prerogatives- tlie^m' tly this faculty he unites, independently of bant' 1 ' |'Jliner images and ideas, and thus creates bril-
ai lvs,' ■ « who must reflect whether he shall make a
novel results. A poet, as Jean Paul Hick ter
13 (ktr™ des F°unnis,’ 1610, p. 150. i pp pg 22^r' Maudsley’s ‘ Physiology and Pathology of Mil
18G8,
46
THE DESCENT OF MAN.
Part I-
character say yes or no — to the devil with him ; he is “ onhr a stupid corpse.” Dreaming gives ns the best notion of this power; as Jean Paul again says, “The “ dream is an involuntary art of poetry.” The value of the products of our imagination depends of course o» 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 o» our power of voluntarily combining them. As dogs, cats, horses, and probably all the higher animals, even birds, as is stated on good authority,14 have vivid dreams, and this is shewn by their movements and voice, we must admit that they possess some power of imagination.
Of all the faculties of the human mind, it will, 1 presume, be admitted that Reason stands at the summit* Few persons any longer dispute that animals possess some power of reasoning. Animals may constantly be seen to pause, deliberate, and resolve. It is a significant fact, that the more the habits of any particular animal are studied by a naturalist, the more he attributes to reason and the less to unlearnt instincts.13 In future chapters we shall see that some animals extremely low in the scale apparently display a certain amount of reason- iSo doubt it is often difficult to distinguish between the power of reason and that of instinct. Thus Dr. Haves, in his work on ‘The Open Polar Sea,’ repeatedly "re- marks that his dogs, instead of continuing to draw the sledges in a compact body, diverged and separated when they came to thin ice, so that their weight might be more evenly distributed. This was often the first’ warn-
14 ®r- Jordon, ‘ Birds of India,’ vol. i. 1S02, p. xxi.
H. Morgan’s work on ‘ The American Beaver,’ 18GS offers a good illustration of this remark. I cannot, however, avoid thinking that he goes too far in underrating tho power of Instinct.
MENTAL POWERS.
47
■Cji.
AP. II.
"S and notice which the travellers received that the ice "as ^econiing thin and dangerous. Now, did the dogs ?.( * ^llls from the experience of each individual, or from
the
example of the older and wiser dogs, or from an
^ i'-rited habit, that is from an instinct? This instinct 'ght possibly have arisen since the time, long ago, . °n dogs were first employed by the natives in draw- oi^ ^1G'r sk‘dges ; or the Arctic wolves, the parent-stock ■ ^le Esquimaux dog, may have acquired this instinct, ^Tolling them not to attack their prey in a close pack qen on thin ice. Questions of this kind are most *®cufr to answer.
si, many facts have been recorded in various works ^owrng that animals possess some degree of reason, '■d I wip here give only two or three instances, authen- utcd Py iJengge^ and relating to American monkeys, j s ^ 1 ®tand low in their order. He states that when . . lsf gave eggs to his monkeys, they smashed them rr U lost much of their contents ; afterwards they q/v. p one end against some hard body, and picked ^ f ie bits of shell with their fingers. After cutting lire llSe ves °nfy once with any sharp tool, they would touch it again, or would handle it with the greatest Lumps of sugar were often given them wrapped
llP in
Paper; and Iiengger sometimes put a live wasp
stu Pal>efr so that in hastily unfolding it they got lieh8 ’ after 1:11 is lia<i ouce happened, they always first witl -tlle lmcket to their ears to detect any movement the Un’ Any one who is not convinced by such facts as that6* aiK^ ^ what he may observe with his own dogs, auvjiarnmaE can reason, would uot be convinced by one U1® f could add. Nevertheless I will give obs ;CaS° respect to dogs, as it rests on two distinct of „ V°fS’ an<f C£ni hardly depend on the modification
1 any instinct.
48
THE DESCENT OP MAN.
Pact I-
Mr. Colquhoun 16 winged two wild-ducks, which fell ou the opposite side of a stream ; his retriever tried to bring over both at once, but could not succeed; she then, though never before known to ruffle a feather, deliberately killed one, brought over the other, and re- turned tor the dead bird. Col. Hutchinson relates that two partridges were shot at once, one being killed, the other wounded ; the latter ran away, and was caught by the retriever, who on her return came across the dead bird; “she stopped, evidently greatly puzzled, and “ after one or two trials, finding she could not take it up “ without permitting the escape of the winged bird, she “ considered a moment, then deliberately murdered it “ by giving it a severe crunch, and afterwards brought “ away both together. This was the only known In- “ stance of her ever having wilfully injured any game.” Here we have reason, though not quite perfect, for the retriever might have brought the wounded bird first and them returned for the dead one, as in the case of the two wild-ducks.
The muleteers in S. America say, “I will not give
you the mule whose step is easiest, but la mas racionah “ —the one that reasons best; ” and Humboldt ,T adds, “ this popular expression, dictated by long experience, “ combats the system of animated machines, better per- “ haps than all the arguments of speculative philosophy.”
It has, I think, now been shewn that man and tin? higher animals, especially the Primates, have some few instincts in common. All have the same senses, intui- tions and sensations — similar passions, affections, and emotions, even the more complex ones; they feel
10 ‘The Moor and the Loch,’ p. 45. Col. Hutchinson oil ‘Dog Breaking,’ 1850, p. 46.
17 ‘Personal Narrative,’ Eng. translat., vol. iii. p. 106.
ClIAP. n.
MENTAL POWERS.
49
fonder and curiosity ; they possess the same faculties mutation, attention, memory, imagination, and reason, , ‘°«Sh in very different degrees. Nevertheless many 11 mrs have insisted that man is separated through his
llf ntal faculties by an impassable barrier from all the
a°'Vei animals. I formerly made a collection of above \ SC01'e of such aphorisms, but they are not worth aS ^eir "Ide difference and number prove the j J “ieulty, if not the impossibility, of the attempt. It !as been asserted that man alone is capable of progres- ?!' e improvement : that he alone makes use of tools or r>le’ domesticates other animals, possesses property, or l3l°JTs language; that no other animal is self-con-
Cl°Us’ c°mprehends itself, has the power of abstraction,
of |)0SSesses general ideas ; that man alone has a sense bid eUUt“'’ *s liable to caprice, has the feeling of grati-
mystery, &c. ; believes in God, or is endowed with Conscience. I will hazard a few remarks on the more
^Portant a
and interesting of these points.
^ ebbishop Sumner formerly maintained18 that man lle ls capable of progressive improvement. With
n. • pvv Vi Y U JUXjJiV/ » CpUJULUi »» A l/AA
11 ms, looking first to the individual, everv one who Uls had
any experience in setting traps knows that
-J VAAp WA iV'J VO JAA OV VAX VA X4X1V M U va»wv
old aai,nals can be caught much more easily than
iJy an
ones ; and they can he much more easily approached
enemy. Even with respect to old animals, it is
^possible to catch many in the same place and in the 0|""' kind of trap, or to destroy them by the same kind
■ i,01s°n j yet it is improbable that all should have j,. °f the poison, and impossible that all should
I e ,een caught in the trap. They must learn caution Am^lng brethren caught or poisoned. In North UlCa> where the fur-hearing animals have long been
Quoted by g;r (j. Lyell, • Antiquity of Mali,’ p. -107.
' I- E
50
THE DESCENT OE MAN.
Pakt I-
pursued, they exhibit, according to the unanimous tes- timony of all observers, an almost incredible amount of sagacity, caution, and cunning ; hut trapping has been there so long carried on that inheritance may have come into play.
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 ; 19 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,20' states that in districts where foxes are much hunted, the young when they first leave their burrows are in- contestably much more wary than the old ones in dis- tricts where they are not much disturbed.
Our domestic dogs are descended from wolves and jackals,21 and though they may not have gained in cunning, and may have lost in waryness and suspicion, yet they have progressed in certain moral qualities, such as in affection, trust-worthiness, temper, and pro- bably in general intelligence. The common rat has conquered and beaten several other species through- out Europe, in parts of North America, New Zealand, and recently in Formosa, as well as on the mainland of China. Mr. Swinhoe,22 who describes these latter cases, attributes the victory of the common rat over the large Jlks coninga to its superior cunning; and this latter quality may be attributed to the habitual exercise of all its faculties in avoiding extirpation by man, as well
10 1 .Journal of Researches daring the Voyage of the “ Beagle,” ’ 18-15, p. 398. ‘ Origin of Species,’ 5th edit. p. 200.
20 ‘Lcttres Phil, sur l’lntelligenee des Aninmux,’ nouvello edit- 1802, p. 86.
21 See the evidence on this head in chap. i. vol. i. ‘ On the Variation of Animals and Plants under Domestication,’
22 ‘ Proc. Zoolog. Soc.’ 1801, p. ISO.
MENTAL POWERS.
51
j.8 dearly all the less cunning or weak-minded rats ^6en successiTely destroyed by him. To main- a . ’ 111 dependent! v of any direct evidence, that no infill <lurinS the course of ages has progressed in of’ ti ' Ct 01 other mental faculties, is to beg the question ac. . 16 Pv°hition of species. Hereafter we shall see that, 8e _°1C lllg to Lartet, existing mammals belonging to toJ6- 01’ders have larger brains than their ancient j'ai’y Prototypes.
hut i 3 °hen been said that no animal uses any tool ; fru‘f 6 chlmpanzee in a state of nature cracks a native oaf I* Somewhat like a walnut, with a stone.23 Eengger 21 hai-f/ an American monkey thus to break open
Use!] h ‘'ha-nuts, and afterwards of its own accord it Ves ^nes to open other kinds of nuts, as well as hark8 r ^ h|Usf also removed the soft rind of fruit that to o a C lsagi’eeable flavour. Another monkey was taught irai-ib'1- ^'e hd of a large box with a stick, and after- ai3(j ^ d Us°d the stick as a lever to move heavy bodies ; a c . laYe myself seen a young orang put a stick into the '1Ce> sIiP his hand to the other end, and use it in tionPi°Per rnanner as a h;ver. In the cases just men- hut tl Stones and sticks were employed as implements ; °Q tl 1Gp aro likewise used as weapons. Erehm 25 states, that ^ a,dhority of the well-known traveller Schimper, specii>n ^yssinia when the baboons belonging to one fain.1' 8 ^a^a) descend in troops from the moun-
ts 0 Plunder the fields, they sometimes encounter fjrr] hS °f another species (C. hamadryas), and then a the tt1181168- phe Geladas roll down great stones, which amadryas try to avoid, and then both species,
1 813.44^° Wyman in ‘Boston Journal of Nat. Hist.’ vol. iv.
a i g.’. p' ' “?■
2s irn.nSetliiere yon Pamo-„o„ > iaon = 51-56.
i83°’ s-
uebcn, B. i. s> 79 j g2-
E 2
52
TliE DESCENT OP MAN.
Taut I.
making a great uproar, rush furiously against each other. Brehm, when accompanying the Duke of Cohura- Gotha, aided in an attack with fire-arms on a troop of baboons in the pass of Mensa iu Abyssinia. The baboons in return rolled so many stones down the mountain, some as large as a man’s head, that the attackers had to beat a hasty retreat ; and the pass was actually for a time closed against the caravan. It deserves notice that these baboons thus acted in concert. Mr. Wal- lace25 on three occasions saw female orangs, accom- panied by their young, “breaking off branches and “ the great spiny fruit of the Durian tree, with every “ appearance of rage ; causing such a shower of missiles “ as effectually kept us from approaching too near the “ tree.”
In the Zoological Gardens a monkey which had weak teeth used to break open nuts with a stone ; and I was assured by the keepers that this animal, after using the stone, hid it in the straw, and would not let any other monkey touch it. Here, then, we have the idea of property ; but this idea is common to every dog with a bone, and to most or all birds with their nests.
The Duke of Argyll 21 remarks, that the fashioning of an implement tor a special purpose is absolutely peculiar to man ; and ho considers that this forms an immeasur- able gulf between him and the brutes. It is no doubt a very important distinction, but there appears to me much truth in Sir J. Lubbock’s suggestion,28 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 intentionally break the
:s ‘ The Malay Archipelago,’ vol. i. 1S69, p. 87.
27 1 Primeval Man,’ 1869, pp. 14a, 147.
26 • Prehistoric Times,’ 1865, p. 473, flic.
Chap. II.
MENTAL POWERS.
Oi>
flints, and not a very wide step to rudely fashion them, flflis latter advance, however, may have taken long ages, if we may judge by tire immense interval of time which elapsed before the men of the neolithic period took to grinding and polishing their stone tools. In breaking the Hints, as Sir J. Lubbock likewise remarks, sparks would have been emitted, and in grinding them beat would have been evolved: “thus the two usual “ Methods of obtaining fire may have originated.” The Mature of fire would have been known in the many Volcanic regions where lava occasionally flows through Crests. The anthropomorphous apes, guided probably by instinct, build for themselves temporary platforms ; but as many instincts are largely controlled by reason, *be simpler ones, such as this of building a platform, rnjght readily pass into a voluntary and conscious act. bbe orang is known to cover itself at night with the foaves of the Pandanus ; and Brehm states that one of bis baboons used to protect itself from the heat of the sun by throwing a straw-mat over its head. In these iatter habits, we probably see the first steps towards s°nre of the simpler arts ; namely rude architecture aud dress, as they arose amongst the early progenitors °f man.
Language. — -This faculty has justly been considered as °ne of the chief distinctions between man and the lower animals. But man, as a highly competent judge, Arch- bishop Whately remarks, “ is not the only animal that ' can make use of language to express what is passing in ‘ bis mind, and can understand, more or less, what is so “ expressed by another.” -9 In Paraguay the Cebus azaree when excited utters at least six distinct sounds, which
Quoted in ‘Anthropological Review,’ 1804, p. 158.
54
THE DESCENT OP 1WAN,
Part I.
excite in other monkeys similar emotions.30 The move- ments of the features and gestures of monkeys are un- derstood by us, and they partly understand ours, as Rengger and others declare. It is a more remark- able fact that the dog, since being domesticated, has learnt to bark31 in at least four or five distinct tones. Although barking is a new art, no doubt the wild spe- cies, the parents 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 ; the yelping or howling bark of despair, as when shut up ; that 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.
Articulate language is, however, peculiar to man; but he uses in common with the lower animals inarti- culate cries to express his meaning, aided by gestures and the movements of the muscles of the face.33 This especially holds good with the more simple and vivid feelings, which are but little connected with our higher intelligence. Our cries of paiu, fear, surprise, anger, to- gether with their appropriate actions, and the murmur of a mother to her beloved child, are more expressive than any words. It is not the mere power of articula- tion that distinguishes man from other animals, for as every one knows, parrots can talk; but it is his large power of connecting definite sounds with definite ideas ; and this obviously depends on the development of the mental faculties.
30 Kenggor, ibid. g. 43.
31 Sec my ‘ Variation of Animals and Plants under Domestication ’ vol. i. p. 27.
32 See a discussion on this subject in Mr. E. B. Tylor’s veiy interest- ing work, ‘Researches into the Early History of Mankind,’ IStio, chaps, ii. to iv.
■ClUp. II.
MENTAL POWERS.
55
As Horne Tooke, one of the founders of the noble science of philology, observes, language is an art, like brewing or baking; but writing would have been a winch, more appropriate simile. It certainly is not a h'Ue instinct, as every language has to be "learnt. It differs, however, widely from, all ordinary arts, for man *las an instinctive tendency to speak, as we see in the babble of our young children ; whilst no child has an lustinctivc tendency to brew, bake, or write. Moreover, j10 philologist now supposes that any language has 1;,een deliberately invented ; each has been slowly and ^consciously 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 that have the power °f singing exert this power instinctively ; but the actual Song> and even the call-notes, are learnt from their Parents or foster-parents. These sounds, as Dailies Barrington 33 has proved, “ are no more innate than language is in man.” The first attempts to sing lu;iy be compared to the imperfect endeavour in a “.child to babble.” The young males continue prac- tising, or, as the bird-catchers say, recording, for ten <J1' eleven months. Their first essays show hardly a Bidiment of the future song; but as they grow older "|e can perceive what they are aiming at ; and at last they are said “to sing their song round.” Nestlings "hieli have learnt the song of a distinct species, as 'yith the canary-birds educated in the Tyrol, teach and h'ansmit their new song to then- offspring. The slight Natural differences of song in the same species inha-
9 3 Bon. Dailies Barrington in 1 Pliilosopli. Transactions,’ 1773, p.
1 ®ee also Dureau de la Malle, in ‘ Ann. des Sc. Nat.’ 3rd series, '4°olog. tom. X. p. 119.
56
THE DESCENT OF MAN.
Part 3.
biting 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 shew that an in- stinctive tendency to acquire an art is not a peculiarity confined to man.
With respect to the origin of articulate language, after having read on the one side the highly interesting' works of Mr. Hensleigh Wedgwood, the Bev. F. Farrar, and Prof. Schleicher,34 and the celebrated lectures of Prof. Max Muller on the other side, I cannot doubt that language owes its origin to the imitation and mo- dification, aided by signs and gestures, of various natural sounds, the voices of other animals, and man’s own instinctive cries. When we treat of sexual selec- tion we shall see that primeval man, or rather some early progenitor of man, probably used his voice largely, as does one of the gibbon-apes at the present day, in. producing true musical cadences, that is in singing ; we may conclude from a widely-spread analogy that this power would have been especially exerted during the courtship of the sexes, serving to express various emotions, as love, jealousy, triumph, and serving as a challenge to their rivals. The imitation by articulate sounds of musical cries might have given rise to words expressive of various complex emotions. As bearing on the subject of imitation, the strong tendency m our nearest allies, the monkeys, in microcephalous
On tlie Origin of Language,’ by H. Wedgwood, 1866. ‘ Chapters on Language,’ by the Rev. F. W. Farrar, 1865. These works are most mterestmg See also 1 De la Phys. et de Parole,’ par Albert Lemoinc, lfefao, p. 196. The work on this subject, by the late Prof. Aug. Schlei- cher, lias been translated by Dr. Bikkers into English, under the title of • Darwinism tested by the Science of Language,’ 1869.
^IUp, IX.
MENTAL POWERS.
57'
ldi°ts,3a and in the barbarous races of mankind, to imi- *a*e whatever tliev hear deserves notice. As monkeys Cei'tainly understand much that is said to them by man,. an<i as in a state of nature they utter signal-cries of danger to their fellows,3" it does not appear altogether ’^credible, that some unusually wise ape-like animal should have thought of imitating the growl of a beast of Prey, so as to indicate to his follow monkeys the nature of the expected danger. And this would have- Je(-'U a first step in the formation of a language.
As the voice was used more and more, the vocal 0l'gans would have been strengthened and perfected through the principle of the inherited effects of use ; '"®d this would have reacted on the power ol speech..
■d the relation between the continued use of language and the development of the brain has no doubt been far 111 ore important. The mental powers in some early pro- genitor 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 vc may confidently believe that the continued use and advance- ment of this power would have reacted on the mind by tabling and encouraging it to carry on long trains ot thought. A long and complex train of thought can no ^ore 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 ordinary trains of thought almost require some form of language, for the dumb, deaf, and blind girl, Laura Bridgman, was observed to use ber fingers whilst dream-
^°gt, ‘Memoirc stir les Microcephales,’ 1867, p. 169. With, ^speot to savages, I have given some facts in my ‘ Journal of ' 'esoatohM,* &c., 1845, p. 206.
“ See clear evidence on this head in the two works so often quoted,. -v Brehm and Rengger,
•58
THE DESCENT OF MAN.
Part I-
ing.'f‘ Nevertheless a long succession of vivid and con- nected ideas, may pass through the mind without the aid of any form of language, as we may infer from the prolonged dreams of dogs. We have, also, seen that retriever-dogs are able to reason to a certain extent: and this they manifestly do without the aid of language. Ihe intimate connection between the brain, as it is non developed in us, and the faculty of speech, is well shewn by those curious cases of brain-disease, in which speech is specially affected, as when the power to re- member substantives is lost, whilst other words can be correctly used.* There is no more improbability in the effects of the continued use of the vocal and mental organs being inherited, than in the case of hand- writing, which depends partly on the structure of the hand and partly on the disposition of the mind ; and hand-writing is certainly inherited.39
Why the organs now used for speech should have been originally perfected for this purpose, rather than any other organs, it is not difficult to see. Ants have considerable powers of intercommunication by means of their an ten me, as shewn by Huber, who devotes a whole chapter to their language. We might have used oui fingers as efficient instruments, for a person with practice can report to a deaf man every word of a speech rapidly delivered at a public meeting; but the loss of our hands, whilst thus employed, would have been a serious inconvenience. As all the higher mammals possess vocal organs constructed on the same general
See remarks oil this head by Dr. Maudsley, ‘The PhvsioW an^ Pathology of Mind,’ 2nd edit. 1868, p. 199. 3 °3
*T,51mdWoJrUri0tIS-CaSeS hilV0 been reeorded- See, for instance, isss' p 130° U“S the Intellcctunl Powers,’ by Dr. Abercrombie,
ii p (j’TllC Variation of AnimaIs and Plants under Domestication,’ yob
'Ciiap. h.
MENTAL POWERS.
59
Pjaa with ours, and which are used as a means of commu- nication, it was obviously probable, if the power of com- 1TUuii cation had to be improved, that these same organs Av°uld have been still further developed ; and this has keen effected by the aid of adjoining and well-adapted bai'ts, namely the tongue and lips.40 The fact of the nigher apes not using their vocal organs for speech, no d°ubt depends on their intelligence not having been sufficiently advanced. The possession by them of organs, n’hich with long-continued practice might have been used for speech, although not thus used, is paralleled by case of many birds which possess organs fitted for Paging, though they never sing. Thus, the nightingale aud crow have vocal organs similarly constructed, these being used by the former for diversified song, and by 1*lc latter merely for croaking.41
The formation of different languages and of dis- tffiet species, and the proofs that both have been de- veloped through a gradual process, are curiously the same.43 Bat we can trace the origin of many words ’U'tlier back than in the case of species, for we can Perceive how they have actually arisen from the Imitation of various sounds. We find in distinct anguages striking homologies due to community of ( escent, and analogies due to a similar process of
j)| |^ee some good remarks to this effect by Hr. Blaudsley, ‘ The ^'ology and Pathology of Blind,’ 186S, p. 109.
BlacgilUvray, ‘Hist, of British Birds,’ vol. ii. 1839, p. 29. An kcelient observer, Mr. Blackwall, remarks that tho magpie learns to 1 fonounce single words, and even short sentences, more readily than '1 m°sX any other British bird ; yet, ns lie adds, after long and closely ▼ostigating its habits, he lias never known it, in a state of nature, usplay any unusual eapil0itv for imitation. ‘ Researches in Zoology,’ X83h p. 15S.
42 Q
aee the very interesting parallelism between the development of Peeies and languages, given by Sir 0. Lyell in ‘ The Geolog. Evidences J uo Antiquity of Man,’ 1863, chap. x-xiii.
60
THE DESCENT OF MAN.
Part L
formation. The manner in which certain letters or sounds change when others change is very like corre- lated growth. We have in both eases the reduplication of parts, the effects of long-continued use, and so forth. The frequent presence of rudiments, both in languages and in species, is still more remarkable. The letter m in the word am, means I; so that in the expression I am . a superfluous and useless rudiment has been retained. In the spelling also of words, letters often remain as the rudiments of ancient forms of pronunciation. Languages, like organic beings, can be classed in groups under groups ; and they can be classed either naturally according to descent, or artificially by other characters. Dominant languages and dialects spread widely and lead to the gradual extinction of other tongues. A lan- guage, like a species, when once extinct, never, as Sir C. Lyell remarks, reappears. The same language never has two birth-places. Distinct languages may be crossed or blended together.*13 We see variability in every tongue, and new words are continually cropping up ; but as there is a limit to the powers of tho memory, single words, like whole languages, gradually become extinct. As Max Mill lor 11 has well remarked: — “ A stru°sfle for “ life is constantly going on amongst the words and gram- “ matical forms in each language. The better, tho “ shorter, the easier forms aro constantly gaining the “ upper hand, and they owe their success to their own “ inherent virtue.” To these more important causes of the survival of certain words, mere novelty may, I think, be added ; for there is in the mind of man a strong love for slight changes in all things. The survival or
43 See remarks to this effect by the Key. V. W, Farrar, in an interest- ing article, entitled “ Philology and Darwinism ” in 1 Nature * March 24th, 1870, p. 528.
44 1 Nature,’ Jan. 6th, 1870, p. 207.
'ClIAP. II.
MENTAL POWERS.
61
preservation of certain favoured words in the struggle '‘°r existence is natural selection.
fhe perfectly regular and wonderfully complex con- struction of the languages of many barbarous nations bas often been advanced as a proof, either of the divine origin of these languages, or of the high art and former civilisation of their founders. Thus F. von Sclilegel " rites : “ In those languages which appear to be at the w lowest grade of intellectual culture, we frequently ob- “ serve a very high and elaborate degree of art m their “ grammatical structure. This is especially the case with u the Basque and the Lapponian, and many of the Ame- “ rican languages.” 45 But it is assuredly au error to speak °f any language as an art in the sense of its having been elaborately and methodically formed. Philolo- gists now admit that conjugations, declensions, &c., ori- ginally existed as distinct words, since joined together ; ond as such words express the most obvious relations between objects and persons, it is not surprising that they should have been used by the men of most races during the earliest ages. "With respect to perfection, tire following illustration will best shew how easily we may err : a Crinoid sometimes consists of no less tiian 150,000 pieces of shell,45 all arranged with per- fect symmetry in radiating lines ; but a naturalist c oes "ft consider an animal of this kind as more perfect tiian a bilateral one with comparatively few parts, and with none of these alike, excepting on the opposite sides of the body. He justly considers the differen- tiation and specialisation of organs as the test ol per- fection. So with languages, the most symmetrical and complex ought not to he ranked above irregular, abbre-
13 Quoted by C. S. Wake, ‘ Chapters on Man,’ 1SG8, p. 101. 40 Buckland, ‘Bridgewater Treatise* p. 411.
62
THE DESCENT OP MAN.
Pap.t I.
viated, and bastardised languages, which have borrowed expressive words and useful forms of construction from various conquering, or conquered, or immigrant races.
From these few and imperfect remarks I conclude that the extremely complex and regular construction of many barbarous languages, is uo proof that they owe their origin to a special act of creation.47 Nor, as we have seen, does the faculty of articulate speech in itself offer any insuperable objection to the belief that man has been developed from some lower form.
Self-consciousness, Individuality, Abstraction, General Ideas, &c. — It would be useless to attempt discussing those high faculties, which, according to several recent writers, make the sole and complete distinction between man and the brutes, for hardly two authors agree in then- definitions. Such faculties could not have been fully developed in man until his mental powers had advanced to a high standard, and this implies the use of a perfect language. No one supposes that one of the lower ani- mals reflects whence he comes or whither he goes, — • what is death or what is life, and so forth. But can we feel sure that an old dog with an excellent memory and some power of imagination, as shewn by his dreams, never reflects on his past pleasures in the chase? and this would be a form of self-consciousness. On the other hand, as Buchner 4S has remarked, how little can the hard-worked wife of a degraded Australian savage, who uses hardly any abstract words and cannot count above four, exert her self-consciousness, or reflect on the nature of her own existence.
47 See some good remarks on the simplification of languages, by Sir J. Lubbock, ‘ Origin of Civilisation,’ 1S70, p. 27S.
48 ‘ Conferences snr In The'orie Darwiniennc,’ French translat., 1SG9, p. 132.
CltAP. II.
MENTAL POWERS.
(13
That animals retain their mental individuality is Unquestionable. When my voice awakened a train of associations in the mind of the above-mentioned ^°g; he must have retained his mental individuality,, although everv atom of his brain had probably under- gone change more than once during the interval of five years. This dog might have brought forward the argument lately advanced to crush all evolutionists, ai'(l said, “I abide amid all mental moods and all ‘ Material changes. . . . The teaching that atoms leave their impressions as legacies to other atoms falling . "‘to the places they have vacated is contradictory of ([ utterance of consciousness, and is therefore false ; ( out it ig the teaching necessitated by evolutionism, consequently the hypothesis is a false one.” 4!l
Sense of Beauty. — This sense has been declared to Je peculiar to man. But when we behold male birds uaborately displaying their plumes and splendid colours "fore the females, whilst other birds not thus deco- lflt°d make no such display, it is impossible to doubt 'at the females admire the beauty of their male part- ners. As women everywhere deck themselves with .ese plumes, the beauty of such ornaments cannot be O'sputed. The Bower-birds by tastefully ornamenting eir playing-passages with gaily-coloured objects, as 0 certain humming-birds their nests, otter additional evidence that they possess a sense of beauty. So with t |(! s°ng of birds, the sweet strains poured forth by the juales during the season of love are certainly admired y the females, of which fact evidence will hereafter be gjven. If female birds had been incapable of appre- ciating the beautiful colours, the ornaments, and voices
The Piev. Dr. J. MlCann, 1 Anti-Darwinism,’ 1869, p. 13.
04 THE DESCENT OF MAH. Part J.
of their male partners, all the labour and anxiety exhi- bited by them in displaying their charms before the females would have been thrown away ; and this it is impossible to admit. Why certain bright colours and certain sounds should excite pleasure, when in harmony, cannot, I presume, be explained any more than why certain flavours and scents are agreeable ; but assuredly the same colours and the same sounds are admired by us and by many of the lower animals.
The taste for the beautiful, at least as far as female beauty is concerned, is not of a special nature in the human mind ; for it differs widely in the different races of man, as will hereafter he shewn, and is not quite the same even in the different nations of the same race. Judging from the hideous ornaments and the equally hideous music admired by most savages, it might be urged that their (esthetic faculty was not so highly developed as in certain animals, for instance, in birds. Obviously no animal would be capable of ad- miring such scenes as the heavens at night, a beautiful landscape, or refined music-; but such high tastes, de- pending as they do on culture and complex associa- tions, are not enjoyed by barbarians or by uneducated persons.
Many of the faculties, which have been of inesti- mable service to man for his progressive advance- ment, such as the powers of the imagination, wonder, •curiosity, an undefined sense of beauty, a tendency to imitation, and the love of excitement or novelty, could not fail to have led to the most capricious changes of customs and fashions. I have alluded to tin's point, because a recent writer80 lias oddly fixed •on Caprice “ as one of the most remarkable and
S9 ‘The Spectator,’ Dec. 4th, 1 SCO, p. 1430.
MENTAL POWERS.
65
-'UP. If.
typical differences between savages and brutes.” But " °t °nly can we perceive how it is that man is capri- <:i0Usj but the lower animals are, as we shall hereafter S®e’ capricious in their affections, aversions, and sense beauty. There is also good reason to suspect that 10 y love novelty, for its own sake.
Relief in God — Religion. — There is no evidence that jUan was aboriginally endowed with the ennobling eb’ef in the existence of an Omnipotent God. On the contrary there is ample evidence, derived not from hasty "travellers, but from men who have long resided with
sayages, that numerous races have existed and still | X|st, who have no idea of one or more gods, and who . ave uo words in their languages to express such an . The question is of course ivholly distinct from uut higher one, whether there exists a Creator and a er of the universe; and this has been answered in j. e affirmative by the highest intellects that have ever
If, however, we include under the term “ religion ” the ,e *e f in unseen or spiritual agencies, the case is wholly ei'ent; for this belief seems to be almost universal "'ib the less civilised races. Nor is it difficult to jomprehend how it arose. As soon as the important |aculties of the imagination, wonder, and curiosity, °{?ether with some power of reasoning, had become
to
Partially developed, man would naturally have craved id
' e vaguely speculated on his own existence. As
understand what was passing around him, and
;n ^ an excellent article on tin's subject by the Rev. F W. Farrar, facts16 "Anthropological Review,’ Ang. 1864, p. ccxvii. For further ari(j see .Si* J. Lubbock, ‘ Prehistoric Times,’ 2nd edit. 1869, p. 564 ; Igyo ■'P'-cially Uie chapters on Religion in his 1 Origin of Civilisation,’
VOL. i.
66
THE DESCENT OF MAN.
Part I-
Mr.. M’Lennan 53 has remarked, “ Some explanation of “ the phenomena of life, a man must feign for himself ;
and to judge from the universality of it, the simplest “ hypothesis, and the first to occur to men, seems to have “ been that natural plienomena are ascribable to the pro- “ sence in animals, plants, and things, and in the forces “ of nature, of such spirits prompting to action as men “ are conscious they themselves possess.” It is probable, as Mr. Tylor lias clearly shewn, that dreams may have first given rise to the notion of spirits ; for savages do not readily distinguish between subjective and objective impressions. When a savage dreams, the figures which appear before him are believed to have come from a distance and to stand over him ; or “ the soul of the- “ dreamer goes out on its travels, and comes home with “a remembrance of what it has seen.”53 But until the above-named faculties of imagination, curiosity, reason, &c., had been fairly well developed in the mind of man, his dreams would not have led him to believe in spirits, any more than in the case of a dog.
Hie W oi'rsh ip of Animals and Plants, in the * Fortnightly Review, Oct. 1, 1S69, p. 422. *
53 Tylor, ‘ Early History of Mankind,’ 1865, p. 0, See also the three striking cha pters on the Development of Religion, in Lubbock’s ‘ Origin of Civilisation,' 1870. In a like manner Mr. Herbert Spencer in his ingenious essay in the ‘ Fortnightly Review’ (May 1st, 1870, p. 535), accounts for the earliest forms of religions belief throughout the world, by man being led through dreams, shadows, and other causes, to look at himself as a double essence, corporeal and spiritual. As the spiritual being is supposed to exist after death and to he powerful, it is propi- tiated by various gifts and ceremonies, and its aid invoked. He then further shows that names or nicknames given from some animal <>r other object to the early progenitors or founders of a tribe, aro sup- posed after a long interval to represent the real progenitor of the tribe ; and such animat or object is then naturally believed still to exist a spirit, is held eacred, and worshipped as a god. Nevertheless I cannot but suspect that there is a still earlier and ruder stage, when anything which manifests power or movement is thought to bo endowed with some form of life, and with mental faculties analogous to our own.
CiUr. II.
MENTAL POWERS.
67
ilie tendency in savages to imagine that natural objects and agencies are animated by spiritual or living essences, is perhaps illustrated by a little fact which 1 °uce noticed : my dog, a full-grown and very sensible mnmal, was lying on the lawn during a hot and still Uay ; but at a little distance a slight breeze occasionally moved an open parasol, which would have been wholly disregarded by the dog, had any one stood near it. As "'as, every time that the parasol slightly moved, the growled fiercely and barked. He must, I think, have reasoned to himself in a rapid and unconscious fanner, that movement without any apparent cause “‘bicated the presence of some strange living agent, and 110 stranger had a right to be on his territory.
bhe belief in spiritual agencies would easily pass into le belief in the existence of one or more gods. For Sa,Vages would naturally attribute to spirits the same passions, the same love of vengeance or simplest form justice, and the same affections which they themselves experienced. The Fuegians appear to be in this respect jn au intermediate condition, for when the surgeon on °ard the “ Beagle ” shot some young ducklings as sPeciniens, York Minster declared in the most solemn manner, “ Oh ! Mr. Bynoe, much rain, much snow, blow' much and this wras evidently a retributive punish- ment for wasting human food. So again lie related l0w> when liis brother killed a “ wild man,” storms long ]'aged, much rain and snow' fell. Yet we eoidd never c iscover that the Fuegians believed in w'hat we should a God, or practised any religious rites ; and Jemmy utton, with justifiable pride, stoutly maintained that mre was no devil in his land. This latter assertion is 10 more remarkable, as with savages the belief in . spirits is far more common than the belief in good
spirits.
68
THE DESCENT OE MAN.
Part 1.
The feeling of religious devotion is a highly com- plex one, consisting of love, complete submission to an exalted and mysterious superior, a strong sense of dependence, 54 fear, reverence, gratitude, hope for the future, and perhaps other elements. No being could experience so complex au emotion until advanced in his intellectual and moral faculties to at least a mode- rately high level. Nevertheless we see some distant approach to this state of mind, in the deep love of a dog for his master, associated with complete submission, some fear, and perhaps other feelings. The behaviour of a dog when returning to his master after an ab- sence, and, as I may add, ot a monkey to his beloved keeper, is widely different from that towards their fellows. In the latter case the transports of joy appear to be somewhat less, and the sense of equality is shewn in every action. Professor Braubach55 goes so far as to maintain that a dog looks on his master as on a god.
The same high mental faculties which first led man to believe in unseen spiritual agencies, then in fetish- ism, polytheism, and ultimately in monotheism, would infallibly lead him, as long as his reasoning pow'ers remained poorly developed, to various strange super- stitions and customs. Many of these are terrible to think of — such as the sacrifice of human beings to a blood-loving god ; the trial of innocent persons by the ordeal of poison or fire ; witchcraft, &c. — yet it is well occasionally to reflect on these superstitions, for they shew us what an infinite debt of gratitude we owe to the improvement of our reason, to science, and our
54 See an able article on the rKj'ekioal Elements of Religion, by Mr. L. Owen Pike, in • Anthropolog. Review,’ April, 1870, p. Ixiii.
55 1 Religion, Moral, &e., der Daiwin’schcn Art-T.ehre,’ 1869, s. 53.
ClIAP. IIg
MENTAL POWERS.
69
Uf-cumulatccl knowledge.56 As Sir J. Lubbock lias well observed, “ it is not too muck to say that the horrible dread of unknown evil hangs like a thick cloud over savage life, and embitters every pleasure.” These ’Miserable and indirect consequences of our highest Acuities may be compared with the incidental and occasional mistakes of the instincts of the lower animals.
50 ‘Prehistoric Times,’ 2 ad edit. p. 571. In this work (at p. 553) oiere will bo found an excellent account of the many strange and capricious customs of savages.
70
THE DESCENT OF MAN.
Part L
CHAPTER III.
Comparison of tiie Mental Powers of Man and the Lower Animals — continued.
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 — - T he self-regarding virtues acquired at a later stage of development — The importance of the judgment of the members of the same community on conduct Trans-
mission of moral tendencies — Summary.
I fully subscribe to the judgment of those writers' who maintain that of all the differences between man and. the lower animals, the moral sense or conscience is by far the most important This sense, as Mack- intoshJ remarks, “has a rightful supremacy over every other principle ot human action; ’ it is summed up in that short but imperious word ought, so full of high significance. It is the most noble of all the attributes of man, leading him without a moment’s hesitation to risk his life for that of a fellow- creature ; or after due deliberation, impelled simply by the deep feeling of right or duty, to sacrifice it in some great cause. Immanuel Kant exclaims, “ Duty ! Wondrous thought, “ that workest neither by fond insinuation, flattery, nor “ bY any threat, but merely by holding up thy naked “ blw in the soul, and so extorting for thyself always
1 See, for instance, on this subject, Quatrefages, ‘ Unite' de l’Espece Humaine,’ 1S(J1, p. 21, &c.
2 ‘ Dissertation on Ethical Philosophy,’ 1837, p. 231, Ac.
'Chap. ni.
MO UAL SENSE.
71
“ reverence, if not always obedience ; before whom all “ appetites are dumb, however secretly they rebel ;
‘ whence thy original ?”3
This great question has been discussed by many Writers4 of consummate ability; and my sole excuse for touching on it is the impossibility of here passing it over, and because, as far as I know, no one has ap- proached it exclusively from the side of natural history. The investigation possesses, also, some independent in- terest, as an attempt to see how far the study of the lower animals can throw light on one ol the highest Psychical faculties of man.
The following proposition seems to me in a high degree probable— namely, that any animal whatever, endowed with well-marked social instincts,5 * * * * * 11 would inevi- tably acquire a moral sense or conscience, as soon as
3 1 Metaphysics of Ethics,* translated by J. \V. Semple. Edinburgh, l836, p. 136.
_ 4 Mr. Bain gives a list (‘Mental and Moral Science,’ 18G8, p. o43-
' -“•!) of twenty-six British authors who have written on this subject, and whoso names arc familiar to every reader ; to these, Mr. Bain’s own
llame, and those of Mr. Becky, Mr. Sbadworth Hodgson, and Sir J.
Lubbock, as well as of others, may be added. t
* Sir B. Brodie, after observing that man is a social animal (‘ x’sy-
ehological Enquiries,’ 1854, p. 102), asks tiro pregnant question,
‘‘ ought not this to settle the disputed question as to the existence ot a
11 moral sense ?” Similar ideas have probably occurred to many persons, as they did long ago to Marcus Aurelius. Mr. J. 8. Mill speaks, in Lis celebrated work, ‘ Utilitarianism,’ (1864, p. 40), of the social feelings a “powerful natural sentiment,’’ and as tho natural basis of “sentiment for utilitarian morality;” but on the previous page he says, “if, as is my own belief, the moral -feelings are not innate, but . acquired, they are not for that reason less natural. It is w ith hesita- tion that I venture to differ from so pro! mold a thinker, hut it can hardly ho disputed that the social feelings are instinctive or innate in the lower animals ; and why should they not bo so ill man ? Mr. Bain (see, for instance, * The Emotions and the Will,’ 18G5, p. 481) and others believe that the moral sense is acquired by each individual during his lifetime. On the general theory of evolution .this is at least extremely improbable.
72
THE DESCENT OF MAN.
J’aet I-
its intellectual powers Lad become as well developed, or nearly as well developed, as in man. For, firstly, the social instincts lead an animal to take pleasure in the society of its fellows, to feel a certain amount of sympathy with them, and to perform various services for them. The services may be of a definite and evi- dently instinctive nature; or there may be only a wish and readiness, as with most of the higher social animals,, to aid their fellows in certain general ways. But these- feelings and services are by no means extended to all the individuals of the same species, only to those of the same association. Secondly, as soon as the mental faculties had become highly developed, images of all past actions and motives would he incessantly passing- through the brain of each individual ; and that feeling of dissatisfaction which invariably results, as we shall hereafter see, from any unsatisfied instinct, would arise, as often as it was perceived that the enduring and always present social instinct had yielded to some°other instinct, at the time stronger, but neither enduring in its nature, nor leaving behind it a very vivid impres- sion. It is clear that many instinctive desires, such as that of hunger, are in their nature of short duration r and after being satisfied are not readily or vividly re- called. Thirdly, after the power of language had been acquired aud the wishes of the members of the same community could be distinctly expressed, the common opinion how each member ought to act for the public good, would naturally become to a large extent the guide to action. But the social instincts would still give the impulse to act for the good of the community, this im- pulse being strengthened, directed, and sometimes even deflected by public opinion, the power of which rests, as we shall presently see, on instinctive sympathy. Lastly,. habit in the individual would ultimately play a very
Chap, m.
MORAL SENSE.
78'.
important part in guiding tlie conduct of each member ;
the social instincts and impulses, like all other in- stincts, would be greatly strengthened by habit, as " Quid obedience to the wishes and judgment of the com- munity. These several subordinate propositions must n°w be discussed; and some of them at considerable
length.
It may be well first to premise that I do not wish to maintain that any strictly social animal, if its intellec- tual faculties were to become as active and as highly 'leveloped as in man, would acquire exactly the same moral sense as ours. In the same manner as various uuirnals have some sense of beauty, though they admire "idely different objects, so they might have a sense of llght and wrong, though led by it to follow widely dif- ferent lines of conduct. If, for instance, to take an ex- ti'erne case, men were reared under precisely the same conditions as hive-bees, there can hardly be a doubt that our unmarried females would, like the worker- Jee‘S, think it a sacred duty to kill their brothers, and mothers would strive to kill their fertile daughters ; and no one would think of interfering. Nevertheless- the bee, or any other social animal, would in our sup- pled case gain, as it appears to me, some feeling of 1]ght and wrong, or a conscience. For each individual A' °Uld have an inward sense of possessing certain stronger or more enduring instincts, and others less strong or enduring ; so that there would often be a struggle which impulse should be followed; and satis- taction or dissatisfaction would be fedt, as past impres- S1°ns were compared during their incessant passage through the mind. In this case an inward monitor 'v°uld tell the animal that it would have been better to have followed the one impulse rather than the other. ^ he one course ought to have been followed : the one
74
TIIE DESCENT OP HAN.
Part I.
"would have been right and the other wrong; but to these terms I shall have to recur.
Sociability. Animals of many kinds are social ; we fiud even distinct species living together, as with some American monkeys, and with the united flocks of rooks, jackdaws, and starlings. Man show's the same feeling in his strong love for the dog, which the dog returns v'ith interest. Every one must have noticed how mise- rable horses, dogs, sheep, &c. are when separated from their companions ; and what affection at least the tvvo foi mer kinds show on their reunion. Xt is curious to speculate on the feelings of a dog, who will rest peace- fully for hours in a room with his master or any of the family, without the least notice being taken of him ; but if left for a short time by himself, barks or howls dis- mally. We will confine our attention to the higher social animals, excluding insects, although these aid each other in many important ways. The most common sen ice which the higher animals perform for each other, is the warning each other of danger by means of the united senses ol all. Every sportsman knows, as Dr. Jaeger remarks,6 how difficult it is to approach animals m a herd or troop. Wild horses and cattle do not, I believe, make any danger-signal ; but the attitude of any one w'ho first discovers an enemy, warns the others. Rabbits stamp loudly on the ground with their hind-feet as a signal : sheep and chamois do the same, but with their fore-feet, uttering likewise a whistle. Many birds and some mammals post sentinels, which in the case of seals are said7 generally to be the females. The leader of a troop of monkeys acts as the sentinel, and utters •cries expressive both of danger and of safety.8 Social
6 ‘Die Darwiu’sohe Tlieorie,’ s. 101.
Mr. It. Brown in ‘Proc. Zoolog. Soc.’ 18G8 p 409
’ Brehm, ‘Thierleben,’ B. i. 1804, s. 52, 79. ‘ For tlic case of the
^up. hi.
MORAL SENSE.
75
•animals perform many little services for each other: horses nibble, and cows lick each other, on any spot "hicli itches : monkeys search for each other s external Parasites ; and Brehm states that after a troop of the ^ercopithecus griseo-viridis has rushed through a thorny brake, each monkey stretches itself on a branch, and another monkey sitting by “conscientiously” examines its fur and extracts every thorn or burr.
Animals also render more important services to each other: thus wolves and some other beasts of prey hunt in packs, and aid each other in attacking their victims. ■Pelicans iish in concert. The Hamadryas baboons turn over stones to find insects, &c. ; and when they come to a large one, as many as can stand round, turn it over together and share the booty. Social animals mutually defend each other. The males of some ruminants come to the front when there is danger and defend the herd with their horns. I shall also in a future chapter give eases of two young wild bulls attacking an old one in eoncert, and of two stallions together trying to drive away a third stallion from a troop of mares. Brehm encountered in Abyssinia a great troop of baboons which were crossing a valley : some had already ascended the opposite mountain, and some were still in the valley : tlje latter were attacked by the dogs, but the old males immediately hurried down from the rocks, and witn mouths widely opened roared so fearfully, that the dogs Precipitately retreated. They were again encouraged to the attack ; but by this time all the baboons had le- nscended the heights, excepting a young one, about six
•wonkeys extracting thorns from each other, see s. 54. \\ ith respect to the Hamadryas turning over stones, the fact is given (s. 76) on the evidence of Alvarez, whose observations Brehm thinks quite trust- worthy. 1’or the cases of the old male baboons attacking the dogs, see s- 79 ; and with respect to the eagle, s. 56.
70
THE DESCENT OF MAH.
Part I.
months old, who, loudly calling for aid, climbed on a block of rock and was surrounded. Now one of the largest males, a true hero, came down again from the mountain, slowly went to the young one, coaxed him, and triumphantly led him away — the dogs being too much astonished to make an attack. I cannot resist giving another scene which was witnessed by this same naturalist; an eagle seized a young Cercopithecus.. which, by clinging to a branch, was not at once carried off; it cried loudly for assistance, upon which the other members of the troop with much uproar rushed to the rescue, surrounded the eagle, and pulled out so many feathers, that he no longer thought of his prey, but only how to escape. This eagle, as Urchin remarks, assuredly would never again attack a monkey in a troop.
It is certain that associated animals have a feeling of love for each other which is not felt by adult and non- social animals. How far in most cases thev actually sympathise with each other’s pains and pleasures is more doubtful, especially with respect to the latter. Mr. Buxton, however, who had excellent means of observation, states that his macaws, which lived free in Norfolk, took “an extravagant interest” in a pair with a nest, and whenever the female left it, she was surrounded by a troop “screaming horrible accla- “ mations in her honour.” It is often difficult to judge whether animals have any feeling for each other's sufferings. Who can say what cows feel, when they surround and stare intently on a dying or dead companion? That animals sometimes are far from feeling any sympathy is too certain ; for they will expel a wounded animal from the herd, or gore or worry it to death. This is almost the blackest tact in natural
9 ‘ Annals and Mag. of Nat. Hist.’ November, 1808, p. 382.
■Chap. III.
MORAL SENSE.
77
history, unless indeed the explanation which has been suggested is true, that their instinct or reason leads them to expel an injured companion, lest beasts of prey, including man, should be tempted to follow the troop. In this ease their conduct is not much worse than that of the North American Indians who leave their feeble comrades to perish on the plains, or the Feegeans, who, when their parents get old or fall ill, bury them alive.10
Many animals, however, certainly sympathise with each other’s distress or danger. This is the case even with birds ; Capt. Stansburyu found on a salt lake in Utah an old and completely blind pelican, which was Wery fats and must have been long and well fed by his companions. Mr. Blyth, as he informs me, saw Indian crows feeding two or three of their companions which Were blind ; and I have heard of an analogous case with the domestic cock. We may, if we choose, call these actions instinctive ; hut such cases are much too rare for the development of any special instinct.12 I have myself seen a dog, who never passed a great triend of his, a cat which lay sick in a basket, with- out giving her a few licks with his tongue, the surest S]gn of kind feeling in a dog.
It must be called sympathy that leads a courageous •log to fly at any one who strikes his master, as he certainly will. I saw a person pretending to beat a lady who had a very timid little dog on her lap, and the trial hail never before been made, the little crea-
10 Sir J. Lubbock, ‘ Prehistoric Times,’ 2nd edit. p. 4L0.
" As quoted by Mr. L. H. Morgan, * The American Beaver,’ 18G8, 1». 272. Capt. Stanabury also gives an interesting account of the man- ncr in which a very yonng pelican, carried away by a strong stream, m as guided and encouraged in its attempts to reach the shore by half a dozen old birds.
12 As Mr. Bain states, “ effective aid to a sufferer springs from sym- pathy proper:” ‘ Mental and Moral Science,’ 1808, p. 245.
78
THE DESCENT OF MAN.
Part I-
ture instantly jumped away, but after the pretended beating was over, it was really pathetic to see how per- severingly he tried to lick bis mistress’s face and com- fort her. Brehm53 states that when a baboon in con- finement was pursued to be punished, the others tried to protect him. It must have been sympathy in the cases above given which led the baboons and Cercopi- theci to defend their young comrades from the dogs and the eagle. I will give only one other instance of sympathetic and heroic conduct in a little American monkey. Several years ago a keeper at the Zoological Gardens, showed me some deep and scarcely healed wounds on the nape of his neck, inflicted on him whilst kneeling on the floor by a fierce baboon. The little American monkey, who was a warm friend of this keeper, lived in the same large compartment, and was dreadfully afraid of the great baboon. Nevertheless, as soon as he saw his friend the keeper in peril, he rushed to the rescue, and by screams and bites so distracted the baboon that the man was able to escape, after running' great risk, as the surgeon who attended him thought, of his life.
Besides love and sympathy, animals exhibit other qualities which in us would be called moral ; and I agree with Agassiz14 that dogs possess something very like a conscience. They certainly possess some power of sell- command, and this does not appear to be wholly the result of fear. As Braubach15 remarks, a dog will refrain from stealing food in the absence of his master. Dogs have long been accepted as the very type of fidelity and obedience. All animals living in a body which defend each other or attack their enemies
13 ‘ Thierleben,’ B. i. s. 85.
14 ‘ Do l’Espece et de la Class.’ 18G9, p. 97.
15 ‘Dor Darwin’selien Avt-Lchre,’ 1809, s. 51.
Uhap. III.
MORAL SENSE.
79
in concert, must be in some degree faithful to each other; and those that follow a leader must be in some degree obedient. When the baboons in Abys- sinia16 plunder a garden, they silently follow their leader ; and if an imprudent young animal makes a noise, he receives a slap from the others to teach him silence and obedience; but as soon as they are sure that there is no danger, all show their joy by much clamour.
With respect to the impulse which leads certain nnimals to associate together, and to aid each other in many ways, we may infer that in most cases they are impelled by the same sense of satisfaction or pleasure which they experience in performing other instinctive notions ; or by the same sense of dissatisfaction, as in other cases of prevented instinctive actions. We see this in innumerable instances, and it is illustrated in a striking manner by the acquired instincts of our domesticated animals; thus a young shepherd-dog delights in driving and running round a ilock of sheep, hut not in worrying them ; a young foxhound delights in hunting a fox, whilst some other kinds of dogs as I have witnessed, utterly disregard foxes. What a strong feeling of inward satisfaction must impel a bird, s° full of activity, to brood day after day over her eggs. -Migratory birds are miserable if prevented from migiat- ing, and perhaps they enjoy starting on their long flight. Some few instincts are determined solely by Painful feelings, as by fear, which leads to self-preser- vation, or is specially directed against ceitain enemies. -No one, I presume, can analyse the sensations of pleasure or pain. In many eases, however, it is pro- bable that instincts are persistently followed from the
16 Brelim, 1 Thierleben,’ B. i. s. 76.
■so
THE DESCENT OF MAN.
Part I.
mere force of inheritance, without the stimulus of either pleasure or pain. A young pointer, when it first scents game, apparently cannot help pointing. A squirrel in a cage who pats the nuts which it cannot eat, as if to bury them in the ground, can hardly be thought to act thus either from pleasure or pain. Hence the common assumption that men must be impelled to every action hy experiencing some pleasure or pain may be erro- neous. Although a habit may be blindly and implicitly followed, independently of any pleasure or pain felt at the moment, yet if it be forcibly and abruptly checked,
vague sense of dissatisfaction is generally expe- rienced ; and this is especially true in regard to persons of feeble intellect.
It has often been assumed that, animals were in the first place rendered social, and that they feel as a con- sequence uncomfortable when separated from each other, and comfortable whilst together; but it is a more pro- bable view that these sensations were first developed, in order that those animals which would profit bv living in society, should be induced to live together. In the same manner as the sense of hunger ami the pleasure of eating were, no doubt, first acquired in order to induce animals to eat. rJ he feeling of pleasure from society is probably an extension of the parental or filial affec- tions ; and this extension may be in chief part attributed to natural selection, but perhaps in part to mere habit. For with those animals which were benefited by living in close association, the individuals which took the greatest pleasure in society would best escape various dangers ; whilst those that cared least for their com- rades and lived solitary would perish in greater numbers. "With respect to the origin of the parental and filial affections, which apparently lie at the basis of the social affections, it is hopeless to speculate ; but we
Ciur. in.
MORAL SENSE.
81
1T‘av infer that they have been to a large extent gained through natural selection. So it has almost certainly been with the unusual and opposite feeling of hatred between the nearest relations, as with the worker-bees whick kill their brother-drones, and with the queen-bees 'vhich kill their daughter-queens ; the desire to destroy, histead of loving, their nearest relations having been here of service to the community.
The all-important emotion of sympathy is distinct h'otn that of love. A mother may passionately love her sleeping and passive infant, but she can then hardly be said to feel sympathy for it. The love ol a man for his dog is distinct from sympathy, and so is that of a hog for his master. Adam Smith formerly argued, as has j\fr. Bain recently, that the basis of sympathy lies 111 our strong retentiveness of former states of pain or Pleasure. Hence, “ the sight of another person enduring hunger, cold, fatigue, revives in us some recollection °1 these states, which are painful even in idea. ’ We aro thus impelled to relieve the sufferings of another, order that our own painful feelings may bo at the sanae time relieved. In like manner we are led to Participate in tbe pleasures of others.17 But I cannot fee bow this view explains tbe tact that sympathy :'s excited in an immeasurably stronger degree by a beloved than by an indifferent person. Tlie mere
, ' Sec ihe first and striking chapter in Adam Smiths ‘ i heory of moral Sentiments.’ Also Mr. Bain’s ‘Mental and Moral Science,’ p. 244, and 275-282. Mr. Rain states, that “sympathy is, ' ittdirectly, a source of pleasure to the sympathiser;” and he accounts (lor this through reciprocity. He remarks that “ tin; person benefited, (l or °thers in his stead, may make up, by sympathy and good offices returned, for all tin; sacrifice.” But if, as appears to be ttie ease, if nPatl‘y 18 ^rictly an instinct, its exercise would give direct pleasure, llle same manner as the exercise, as before remarked, of almost every otller instinct.
V0L. I.
G
82
THE DESCENT OP MAN.
Paet I.
sight of suffering, independently of love, would suffice to call up in us vivid recollections and associations. Sympathy may at first have originated in the manner above suggested; but it seems now to have become an instinct, which is especially directed towards be- loved objects, in the same manner as fear with ani- mals is especially directed against certain enemies. As sympathy is thus directed, the mutual love of the members of the same community will extend its limits. No doubt a tiger or lion feels sympathy for the suffer- ings of its own young, but not for any other animal. With strictly social animals the feeling will be more or less extended to all the associated members, as wo know to be the case. With mankind selfishness, expe- rience, and imitation probably add, as Mr. Bain has shewn, to the power of sympathy ; for we are led by the hope of receiving good in return to perform acts of sympathetic kindness to others ; and there can he no doubt that the feeling of sympathy is much strengthened by habit. In however complex a manner this feeling may have originated, as it is ono of high importance to all those animals which aid and defend each other, it will have been increased, through natural selection; for those communities, which included the greatest number of the most sympathetic members, would flourish best and rear the greatest number of offspring.
In many cases it is impossible to decide whether certain social instincts have been acquired through natural selection, or are the indirect result of other instincts and faculties, such as sympathy, reason, expe- rience, and a tendency to imitation ; or again, whether they are simply the result of long-continued habit- So remarkable an instinct as the placing sentinels to warn the community of danger, can hardly have been
'Wap. III.
MORAL SENSE.
83
tile indirect result of any otlier faculty ; it must there- fore have been directly acquired. On the other lianc , tile habit followed by the males of some social animals, of defending the community and of attacking their demies or their prey in concert, may perhaps have originated from mutual sympathy ; but courage, and in most cases strength, must have been previously Acquired, probably through natural selection.
Of the various instincts and habits, some are muc stronger than others, that is, some either give more Pleasure in their performance and more distress m their Prevention than others ; or, which is probably quite as Important, they are more persistently followed throng 1 inheritance without exciting any special feeling of plea- sure or pain. We are ourselves conscious that some habits are much more difficult to cure or change than °thers. Hence a struggle may often be observed in animals between different instincts, or between an instinct and some habitual disposition ; as when a dog bushes after a hare, is rebuked, pauses, hesitates, pursues again or returns ashamed to his master ; or as between ihe love of a female dog for ber young puppies and for her master, for slie may be seen to slink away to them, as if half ashamed of not accompanying her master. But the most curious instance known to me of one instinct conquering another, is the migratory instinct conquering the maternal instinct. The former is won- derfully strong; a confined bird will at tlie proper season beat her breast against the wires of her cage, until if is hare and bloody. It causes young salmon to leap ()ut of the freshwater, where they could still continue to tive, and thus unintentionally to commit suicide. Every one knows how strong the maternal instinct is, leading even timid birds to face great danger, though with hesitation and in opposition to the instinct of self-
84
THE DESCENT OF MAN.
Part 1-
preservatiou. Nevertheless the migratory instinct is so powerful that late in the autumn swallows and house- martins frequently desert their tender young, leaving them to perish miserably in their nests.18
We can perceive that an instinctive impulse, if it be in any way more beneficial to a species than some other or opposed instinct, would be rendered the more potent of the two through natural selection ; for the individuals which had it most strongly developed would survive in larger numbers. Whether this is the case with the migratory in comparison with the maternal instinct, may well be doubted. The great persistence or steady action of the former at certain seasons of the year during the whole day, may give it for a time para- mount force.
Man a social animal. — Most persons admit that man is a social being. We see this in his dislike of solitude, and in his wish for society beyond that of his own family. Solitary confinement is one of the severest punishments which can be inflicted. Some authors sup- pose that man primevallv lived in single families ; but at the present day, though single families, or only two or three together, roam the solitudes of some savage lands, they are always, as far as I can discover, friendly with other families inhabiting the same district. Such families occasionally meet in council, and they unite
tliiw fact, the Kcv. J '■ Jouyus states (sea his edition of 1 Whiter Nat. Hist, of Selbome,’ 1853, p. 204) was first recorded Ly the illus- trious Jenner, in 1 Phil. Transact.’ 1824, and has since been confirmed by several observers, especially by Mr. Blackball. This latter careful' observer examined, late in the autumn, during two years, thirty-six nests; he found that twelve contained young dead birds, five contained eggs ou the point of being hatched, and three eggs not nearly hatched- Many birds not yet old enough for a prolonged flight are likewise deserted and leit behind. See Blackwall, ‘ Kesearches in Zoology,' 1834, pp. 108, 118. For some additional evidence, ulthou<dr this is not wanted, see Leroy, * Lottes Phil.’ 1802, p. 217.
MORAL SENSE.
85
"HAP. HI.
^0r their common defence. It is no argument against savage man being a social animal, that the tribes in- habiting adjacent districts are almost always at war 'yith each other; for the social instincts never extend to all the individuals of the same species. Judging ti'om the analogy of the greater number of the Quad- rUmana, it is probable that the early ape-like pro- genitors of man were likewise social ; but this is not of rn,leh importance for us. Although man, as he now exists, has few special instincts, having lost any which his early progenitors may have possessed, this is no Reason why he should not have retained from an ex- tremely remote period some degree of instinctive love and sympathy for his fellows. We are indeed all con- scious that we do possess such sympathetic feelings ; IJ
ut our consciousness does not tell us whether they are instinctive, having originated long ago in the same fanner as with the lower animals, or whether they have been acquired by each of us during our early years.
man is a social animal, it is also probable that he 'vould inherit a tendency to be faithful to his comrades, this quality is common to most social animals. He w°uld in ]j],;e manner possess some capacity for self- command, and perhaps of obedience to the leader of community. He would from an inherited tendency “till he willing to defend, in concert with others, his bdlow-men, and would he ready to aid them in any "ay which did not too greatly interfere with his own "'clfare or liis own strong desires.
-the social animals which stand at the bottom of the
Hume remarks (‘An. Enquiry Concerning the Principles ofMorals, mt. of 1751 , p. 132), “ there seems a necessity for confessing that the „ "fPPiness and misery of others arc not spectacles altogether in- ‘efferent to us, but that the view of the former . . . communicates a *,s.ecret j°y; the appearance of the latter . . . throws a melancholy ’ dnip over the imagination.”
86 THE DESCENT OF MAN. PakT I-
scale are guided almost exclusively, and those which stand higher in the scale are largely guided, in the aid which they give to the members of the same community,- by special instincts ; but they are likewise in part ini' polled by mutual love and sympathy, assisted app*1' rently by some amount of reason. Although man, as just remarked, has no special instincts to tell him how to aid his fellow-men, he still has the impulse, and with his- improved intellectual faculties would naturally be much guided in this respect by reason and experience. In' stinctive sympathy would, also, cause him to value highly the approbation of his fellow-men ; for, as Mr. Bain has clearly shew n,20 the love of praise and the strong feeling of glory, and the still stronger horror of scorn and in* lamy, “ are due to the workings of sympathy.” Conse- quently man would be greatly influenced by the wishes, approbation, and blame of his fellow-men, as expressed by their gestures and language. Thus the social in' stincts, which must have been acquired by man in *l very rude state, and probably even by his early ape-like progenitors, still give the impulse to many of his best actions ; but his actions are largely determined by the expressed wishes and judgment of his fellow-men, and unfortunately still oftener by bis own strong, selfish desires. But as the feelings of love and sympathy and the power of self-command become strengthened by habit, and as the power of reasoning becomes clearer so that man can appreciate the justice of the judgments of his fellow-men, he will feel himself impelled, independ- ently of any pleasure or pain felt at the moment, 1° certain lines of conduct. He may then say, I am the supreme judge of my own conduct, and in the words of Kant, 1 will not in my own person violate the dignity of humanity.
20 * Mental and Moral Science,’ 1S6S, p. 251.
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The more enduring Social Instincts conquer the less Persistent Instincts. — We have, however, not as yet con- sidered the main point, on which the whole question of the moral sense hinges. Why should a man feel that he ought to obey one instinctive desire rather than another? Why does he bitterly regret if he has yielded to the strong sense of self-preservation, and has not risked his life to save that of a fellow-creature ; or why does he regret having stolen food from severe hunger ?
It is evident in the first place, that with mankind the instinctive impulses have different degrees ol strength , a young and timid mother urged by the maternal in- stinct will, without a moment’s hesitation, run the greatest danger for her infant, hut not lor a mere fel- low-creature. Many a man, or even boy, who never before risked his life for another, but in whom courage and sympathy were well developed, has, disregarding the instinct of self-preservation, instantaneously plunged into a torrent to save a drowning fellow-creature. In this case man is impelled by the same instinctive mo- tive, which caused the heroic little American monkey, formerly described, to attack the great and dreaded baboon, to save his keeper. Such actions as the above appear to be the simple result of the greater strength of the social or maternal instincts than of any other instinct or motive ; for they are performed too instantaneously for reflection, or for the sensation ot pleasure or pain , though if prevented distress would be caused,
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 to actions prompted by some lofty motive. But it appears scarcely possible to draw any clear line
88
THE DESCENT OF MAN.
Taut I.
ol distinction of this kind ; though the distinction may be real. As far as exalted motives are concerned, many instances have been recorded of barbarians, destitute of any feeling of general benevolence towards mankind, and not guided by any religious motive, who have deli- berately as prisoners sacrificed their lives,-1 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, ani- mals may be seen doubting between opposed instincts, as in rescuing their offspring or comrades from dan- ger; yet their actions, though done for the good of others, are not called moral. Moreover, an action repeatedly performed by us, will at last be done with- out deliberation or hesitation, and can then hardly be distinguished from an instinct; yet surely no one will pretend that an action thus done 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, uuless 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 sym- pathy before he acts, deserves, however, in one way highei 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, when they are performed by a moral being. A moral being is one who is capable of comparing his past and future actions or motives, and of approving or disapproving of them. We have no reason to suppose that any of the lower animals have
21 I have given one such case, namely of three Patagonian Indians who preferred being shot, one after the other, to betraying the plans of their companions m war (‘ Journal of Researches,* 1845, p. 103).
<!‘U.p. III.
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this capacity ; therefore when 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 certainly be ranked as a moral being, actions of a certain class are called moral, whether performed deliberately alter a struggle with opposing motives, or from the effects of slowly-gained habit, or impulsively through instinct.
But to return to our more immediate subject; al- though some instincts are more powerful than others, thus leading to corresponding actions, yet it cannot he maintained that the social instincts are ordinarily stronger in man, or have become stronger through long-continued habit, than the instincts, for instance, ■°f self-preservation, hunger, lust, vengeance, &c. Why then does man regret, even though ho may endeavour to banish any such regret, that he has followed the one natural impulse, rather than the other ; and why does he further feel that he ought to regret his conduct ? Man in this respect differs profoundly from the lower animals. Nevertheless we can, I think, see with some degree of clearness the reason of this difference.
Man, from the activity of his mental faculties, cannot {lyoid reflection: past impressions and images are in- cessantly passing through his mind with distinctness. Mow with those animals which live permanently in a ^°dy, the social instincts are ever present and per- sistent. Such animals are always ready to utter the danger-signal, to defend the community, and to give u*d to their fellows in accordance with their habits ; diey 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 h'oin them, and always happy to be in their company, it is with ourselves. A man who possessed no trace
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of such feelings 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 vivid- ness the feeling, for instance, of hunger ; nor indeed, as has often been remarked, of any suffering. The in- stinct of self-preservation is not felt except in the pre- sence of danger ; and many a coward has thought him- self brave until he has met his enemy face to face. The wish for another man’s property is perhaps as persistent a desire as any that can be named ; but even in this case the satisfaction of actual possession is gene- rally a weaker feeling than the desire : many a thief, if not an habitual one, after success has wondered why be stole some article.
Thus, as man cannot prevent old impressions con- tinually repassing through his mind, he will be com- pelled to compare the weaker impressions of, for in- stance, past hunger, or of vengeance satisfied or danger' avoided at the cost of other men, with the instinct of sympathy and good-will to his fellows, which is still pre- sent and ever in some degree active in his mind. He will then feel in his imagination that a stronger instinct has yielded to one which now seems comparatively weak ; and then that sense of dissatisfaction will in- evitably be felt with which man is endowed, like every other animal, in order that his instincts may be obeyed- The case before given, of the swallow, affords an illus- tration, though of a reversed nature, of a temporary though for the time strongly persistent instinct con- quering 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-
Chap. III.
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and congregate in flocks. Whilst the motliei-biid is feeding or brooding over her nestlings, the maternal instinct is probably stronger than the migratory ; but the instinct which is more persistent gains the victory, and at last, at a moment when her young ones are not in sbdit, she takes flight and deserts them. When arrived at the end of her long journey, and the migra- tory instinct ceases to act, what an agony of remorse each bird would feel, if, from being endowed with great mental activity, she could not prevent the image con- tinually passing before her mind of her young ones, perishing in the bleak north from cold and hunger.
At the moment of action, man will no doubt be apt to follow the stronger impulse; and though this may occasionally prompt him to the noblest deeds, it will far more commonly lead him to gratify his own desires at the expense of other men. Hut after their grati- fication, when past and weaker impressions are con- trasted with the ever-enduring social instincts, retri- bution will surely come. Man will then feel dissatis- fied with himself, and will resolve with more or less force to act differently for the future. This is con- science ; for conscience looks backwards and judges past actions, inducing that kind of dissatisfaction, whic 1 if weak we call regret, and if severe remorse.
These sensations are, no doubt, different from those experienced when other instincts or desn cs are e t unsatisfied; but every unsatisfied instinct has its own proper prompting sensation, as we recognise with ungei thirst, &c. Man thus prompted, will through long habit acquire such perfect self-command, that his desires and passions will at last instantly yield to his social sympathies, and there will no longer be a struggle between them. The still hungry, or the still revengeful man will not think of stealing food, or of wreaking his.
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THE DESCENT OF MAN.
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vengeance. It is possible, or, as we shall hereafter see, even probable, that the habit of self-command may, like other habits, be inherited. Tims at last man comes to feel, through acquired and perhaps in- herited habit, that it is best for him to obey his more persistent instincts. The imperious word ought seems merely to imply the consciousness of the existence of a persistent instinct, either innate or partly acquired, serving him as a guide, though liable to be disobeyed. ^ e hardly use the word ought in a metaphorical sense, when we say hounds ought to hunt, pointers to point, and retrievers to retrieve their game. If they fail thus to act, 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 to a man, when re- called to mind, as strong as, or stronger than, his social instinct, he will feel no keen regret at having followed it; but lie will be conscious that if his conduct were known to his fellows, it would meet with their disap- probation ; and few are so destitute of sympathy as not to feel discomfort when this is realised. If he” has no such Sympathy, and it his desires leading to bad actions are at the time strong, and when recalled are not over- mastered by the persistent social instincts, then he is essentially a bad man ; 22 and the sole restraining motive left is the fear of punishment, and the conviction that in the long run it would be best for his own selfish interests to regard the good of others rather than his •own.
It is obvious that every one may with an easy con- science gratify his own desires, if they do not interfere
• Dr. Prosper Pet pine, in liis ‘ Psychologie NatureUe,’ 3868 (tom. j. p. ‘2-13; tom. u. p. 169) gives many curious eases of the worst criminals, who apparently have been entirely destitute of con, science.
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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 reasonable or not, of his fellow men. Nor must he break through the fixed habits of his life, especially if these arc supported by reason ; for if he does, he will assuredly feel dissatisfaction. He must likewise avoid the reprobation of the one Hod or gods, in whom according to his knowledge or superstition he may believe ; but in this case the addi- tional fear of divine punishment often supervenes.
The strictly Social Virtues at first alone regarded. — f he above view of the first origin and nature of the moral sense, which tells us what we ought to do, and of the conscience which reproves us if we disobey it. uccords well with what we see of the early and un- developed condition of this faculty in mankind. The virtues which must be practised, at least, generally, by fude men, so that they may associate in a body, are those which are still recognised as the most important. Hut they are practised almost exclusively in relation to tue men of the same tribe ; and their opposites are not regarded as crimes in relation to the men of other tribes. Ho tribe could hold together if murder, robbery, trea- chery, &c., were common ; consequently such crimes within the limits of the same tribe “are branded 'with everlasting infamy;”23 but excite no such senti- ment beyond these limits. A North- American Indian m well pleased with himself, and is honoured by others, when he scalps a man of another tribe ; and a Dyak
Sep an able article in the ‘North British Review,’ 1SG7, p. 395. ' ' cc also Mr. W. Bagolrot’s articles on the Importance of Obedience and Coherence to Primitive Man, in the ‘Fortnightly Review,’ 1 S 07- P‘ 529, and 1S68, p. 457, &c.
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•cuts off the head of an unoffending person and dries it as a trophy. The murder of infants has prevailed on the largest scale throughout the world,24 and has met with no reproach ; but infanticide, especially of females, has been thought to be good for the tribe, or at least not injurious. Suicide during former times was not generally considered as a crime,25 but rather from the courage displayed as an honourable act ; and it is still largely practised by some semi-civilised nations without reproach, for the loss to a nation of a single individual is not felt : whatever the explanation may be, suicide is rare amongst barbarians; the negroes on the west coast of Africa offering, however, as I hear from Mr. W. Eeade, in this respect an exception. It has been recorded that an Indian Thug conscientiously regretted that he had not strangled and robbed as many travellers as did his father before him. In a rude state of civilisa- tion the robbery of strangers is, indeed, generally con- sidered as honourable.
The great sin of Slavery has been almost universal, and slaves have often been treated in au infamous manner. As barbarians do not regard the opinion of their women, wives are commonly treated like slaves. Most savages are utterly indifferent to the sufferings of strangers, or even delight in witnessing them. It is well known that the women and children of the North- American Indians aided in torturing their enemies. Some savages take a horrid pleasure in cruelty to animals,28 aud humanity with them is an unknown virtue. Nevertheless, feelings of sympathy and kindness are common, especially
24 The fullest account which I have met with is by Dr. Gerland, in his ‘ TTfeber das Aussterbeu dor Xaturvolker,’ 18(18 ; but I shall have to recur to the subject of infanticide in a future chapter.
25 See the very interesting discussion on Suicide in Lecky’s ‘ History of European Morals,’ vol. i. 18G9, p. 223.
26 See, for instance, Mr. Hamilton’s account of the Kaffirs, ‘ Anthro- pological Review,’ 1870, p. xv.
Chap. III.
MOEAL SENSE.
05
during sickness, between the members of the same tribe, and are sometimes extended beyond the limits of the tribe. Mungo Park’s touching account of the kindness of the negro women of the interior to him is well known. Many instances could be given of the noble fidelity of savages towards each other, but not to strangers ; common experience justifies the maxim of the Spaniard, “ Never, never trust an Indian.” There cannot be fidelity without truth ; and this fundamental virtue is not rare between the members of the same tribe : thus -Mungo Park heard the negro women teaching their young children to love the truth. This, again, is one ol the virtues which becomes so deeply rooted in the mind that it is sometimes practised by savages even at a high cost, towards strangers ; but to lie to your enemy has rarely been thought a sin, as the history of modern diplomacy too plainly shews. As soon as a tribe has a recognised leader, disobedience becomes a crime, and ■even abject submission is looked at as a sacred virtue.
As during rude times no man can be useful or faithful to his tribe without courage, this quality has universally been placed in the highest rank; and although, in civilised countries, a good, yet timid, man may be far more useful to the community than a brave one, we cannot help instinctively honouring the latter above a coward, however benevolent. Prudence, on the other hand, which does not concern the welfare of others,- though a very useful virtue, has never been highly esteemed. As no man can practise the virtues necessary t'°r the welfare of his tribe without self-sacrifice, self- command, and the power of endurance, these qualities fiave been at all times highly and most justly valued, idle American savage voluntarily submits without a groan to the most horrid tortures to prove and strengthen his fortitude and courage ; and we cannot
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help admiring him, or even an Indian Fakir, who, from a foolish religious motive, swings suspended by a hook buried in his flesh.
The other 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 civilised nations. The greatest intemperance with savages is no reproach. Their utter licentiousness, not to mention unnatural crimes, is something astounding.27 As soon, however, as marriage, whether polygamous or monogamous, becomes common, jealousy will lead to the inculcation of female virtue ; and this being honoured will tend to spread to the unmarried females. How slowly it spreads to the male sex we see at the present day. Chastity eminently requires self-command ; therefore it has been honoured from a very early period in the moral history of civilised man. As a consequence of this, the senseless practice of celibacy has been ranked from a remote period as a virtue.28 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, apper- taining exclusively, as Sir G. Staunton remarks,'* to civilised life. This is shewn 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 affect in an obvious manner the welfare of the tribe, — not that of the species, nor that of man as an individual member of the
27 Mr. MT.ennan bus given (‘Primitive Marriage,’ 18G5, p. 17G) a- good collection of facts on this head.
28 Lecky, ‘ History of European Morals,’ vol. i. I860, p. 10P.
211 ‘Embassy to China, ’ vol. ii. p. 348.
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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 tile community. The chief causes of the low morality of savages, as judged by our standard, are, firstly, the confinement of sympathy to the same tribe. Secondly, insufficient powers of reasoning, so that the bearing ot many virtues, especially of the self-regarding virtues, on the general welfare of the tribe is not recognised. Savages, for instance, fail to trace the multiplied evils consequent on a want of temperance, chastity, &c. And. thirdly, weak power of self-command; lor this power has not been strengthened through long-con- tinued, perhaps inherited, habit, instruction and religion.
I have entered into the above details on the immor- ality of savages,30 because some authors have recently taken a high view of their moral nature, or have attri- buted most of their crimes to mistaken benevolence.31 These authors appear to rest their conclusion on savages possessing, as they undoubtedly do possess, and often in a high degree, those virtues which are serviceable, °r even necessary, for the existence of a tribal com- munity.
Concluding Remarks. — Philosophers of the derivative 1 school of morals formerly assumed that the foundation °f morality lay in a form of Selfishness ; but more recently in the “ Greatest Happiness principle. Ac- cording to the view given above, the moial sense is
30 See on this subject copious evidence in Chap. vii. of Sir J. Fubboclr, ‘Origin of Civilisation/ 1870.
31 For instance Lccky, 1 Hist. European Morals/ vol. i. p. 124.
32 This term is used in an able article in the ‘ Westminister Review,' Oct. 1869, p. 498. For the Greatest Happiness principle, see J. S. Mill, 1 TJt'iitarianism/ p. 17.
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fundamentally identical with the social instincts; and in the case of the lower animals it would be absurd to speak of these instincts as having been developed from selfishness, or for the happiness of the community. They have, however, certainly been developed for the general good of the community. The term, general good, may be defined as the means by which the great- est possible number of individuals can be reared in full vigour and health, with all their faculties perfect, under the conditions to which they are exposed. As the social instincts both of man and the lower animals have no doubt been developed by the same steps, it would be advisable, if found practicable, to use the same definition in both cases, and to take as the test of morality, the general good or welfare of the com- munity, rather than the general happiness ; but this definition would perhaps require some limitation on account of political ethics.
When a man risks his life to save that of a fellow- creature, it seems more appropriate to say that he acts for the general good or welfare, 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 fiourish better than one that is discontented and unhappy. We have seen that at an early period in the history of man, the ex- pressed wishes of the community will have naturally influenced to a large extent the conduct of each mem- ber ; and as all wish for happiness, the “ greatest happi- ness principle” will have become a most important secondary guide and object ; the social instincts, includ- ing sympathy, always serving as the primary impulse and guide. Thus the reproach of laying the foundation of the most noble part of our nature in the base prin- ciple of selfishness is removed ; unless indeed the satis-
Chap. III.
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faction which every animal feels when it follows its proper instincts, and the dissatisfaction felt when pre- vented, be called selfish.
The expression of the wishes and judgment of the members of the same community, at first by oral and afterwards by written language, serves, as just re- marked, as a most important secondary guide of conduct, in aid of the social instincts, but sometimes in opposition to them. This latter fact is well exem- plified bv the haw of Honour, that is the law ot the opinion of our equals, and not of all our country- men. The breach of tins law, even when the breach is known to be strictly accordant with true mo- rality, has caused many a man more agony than a real crime. We recognise the same influence in the burn- ing 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 eti- quette, 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 "’ill not rarely err from ignorance and from weak powers °f reasoning. Hence the strangest customs and super- stitions, in complete opposition to the true welfare and happiness of mankind, have become all-powerful through- cut the world. We see this in the horror felt by a Hindoo who breaks his caste, in the shame of a Maho- metan woman who exposes her face, and in innumerable other instances. It would be difficult to distinguish between the remorse felt by a Hindoo who has eaten Unclean food, from that felt after committing a theft; but the former would probably be the more severe.
How so many absurd rules of conduct, as well as so many absurd religious beliefs, have originated we do u°t know ; nor how it is that they have become, in all
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Part I.
quarters of the world, so deeply impressed on the mind of men ; but it is worthy of remark that a belief con- stantly inculcated during the early years of life, whilst the brain is impressible, appears to acquire almost the nature of an instinct ; and the very essence of an in- stinct 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 appre- ciated by some savage tribes than by others ; 33 nor, again, why similar differences prevail even amongst civilised nations. Knowing how firmly fixed many strange customs and superstitions have become, we need feel no surprise that the self-regarding virtues should now appear to us so natural, supported as they are by reason, 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 relate to the welfare of others. They are supported by the approbation of our fellow- men and by reason. The lower rules, though some of them Avhen implying self-sacrifice hardly deserve to be called lower, relate chiefly to self, and" owe their origin to public opinion, when matured by experience and cultivated ; for they are not practised by rude tribes.
As man advances in civilisation, and small tribes are united into larger communities, the simplest reason would tell each individual that lie ought to exteud his social instincts and sympathies to all the members of the same nation, though personally unknown to him. This point being once reached, there is only an arti-
83 Good instances are given by Mr. Wallace in ‘ Scientific Opinion,’ Sept. 15, 1869 ; and more fully in his ‘ Contributions to the Theory of Natural Selection,’ 1870, p. 353.
Chap. III.
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ficial barrier to prevent bis sympathies extending to the men of all nations and races. If, indeed, such men are separated from him by great differences in appearance or habits, experience unfortunately shews us how long it is before we look at them as our fellow-creatures. Sympathy beyond the confines ol man, that is humanity to the lower animals, seems to be one of the latest moral acquisitions. It is apparently unfelt by savages, except towards their pets. How little the old Romans knew of it is shewn by their abhorrent gladiatorial exhibitions. The very idea of humanity, as tar as I could observe, was new to most of the Gauchos of the Pampas. This virtue, one of the noblest with which man is endowed, seems to arise incidentally from our sympathies becoming more tender and more widely dif- fused, until they are extended to all sentient beings. As soon as this virtue is honoured and practised by some few men, it spreads through instruction and example to the young, and eventually through public opinion.
The highest stage in moral culture at which we can arrive, is when we recognise that we ought to control our thoughts, and “ not even in inmost thought to think “ again the sins that made the past so pleasant to us.”'4 Whatever makes auy had action familiar to the mine , renders its performance by so much the easier. As Marcus Aurelius long ago said, “ Such as are thy habi- “ tual thoughts, such also will be the character of thy “ mind ; for the soul is dyed by the thoughts.
Our great philosopher, Herbert Spencer, has recently explained his views on the moral sense. He says, I
34 Tennyson, * Idylls of the King,’ p. 244.
35 • The Thoughts of the Emperor M. Aurelius Antoninus,’ Eng. translat., 2nd edit., 1869, p. 112. Marcus Aurelius was bom a.d. 121.
36 Letter to Mr. Mill in Bain's ‘Mental and Moral Science,’ 1868, P. 722.
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believe that the experiences of utility organised and “ consolidated through all past generations of the human “ ra<3f> have been producing corresponding modifications, " "hick, hy continued transmission and accumulation, hav'e become in us certain faculties of moral intuition — “ cei'fain emotions responding to right and wrong con- duct, which have no apparent basis in the individual experiences of utility. There is not the least inhe- rent improbability, as it seems to me, in virtuous ten- dencies being more or less strongly inherited ; for, not to mention the various dispositions and habits trans- mitted by many of our domestic animals, I have heard of 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 so rare a crime in the wealthy classes, we can hardly account by accidental coincidence for the tendency occurring in two or throe members of the same family. If bad tendencies are transmitted, it is probable that good ones are likewise transmitted. Ex- cepting through the principle of the transmission of moral tendencies, we cannot understand the differences believed to exist in this respect between the various races ot mankind. We have, however, as yet, hardly sufficient evidence on this head.
Even the partial transmission of virtuous tendencies would be an immense assistance to the primary impulse derived directly from the social instincts, and indirectly from the approbation of our fellow-men. Admitting for the moment that virtuous tendencies are inherited, it appears probable, at least in such cases as chastity, temperance, humanity to animals, &c., that they become first impressed on the mental organisation through habit, instruction, and example, continued during several generations in the same family, and in a quite subor- dinate degree, or not at all, by the individuals jvos-
Chap. III.
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sessing 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, super- stitions, and tastes, such as the horror of a Hindoo tor unclean food, ought on the same principle to be trans- mitted. Although this in itself is perhaps not less pro- bable than that animals should acquire inherited tastes for certain kinds of food or fear of certain foes, I have not met with any evidence in support ot the trans- mission of superstitious customs or senseless habits.
Finally, the social instincts which no doubt were acquired by man, as by the lower animals, for the goo of the community, will from the first have given to him some wish to aid his fellows, and some feeling ot sym- pathy. Such impulses will have served him at a very early period as a rude rule of right and wrong. Hut as man gradually advanced in intellectual power and was enabled to trace the more remote consequences ot ins actions; as he acquired sufficient knowledge to reject baneful customs and superstitions; as he regarded more and more not only the welfare but the happi- ness of his fellow-men ; as from habit, following on beneficial experience, instruction, and example, bis sympathies became more tender and " ic e y c 1 use , so as to extend to the men of all races, to the im- becile, the maimed, and other useless members ot society, and finally to the lower animals,— so would the standard of his morality rise higher and higher. An it is admitted by moralists of the derivative school and by some intuitionists, that the standard of morality has risen since an early period in the history of man.
As a struggle may sometimes be seen going on
37 A -writer in the ■ North British Review ’ (July, 1869, p. 531), well capable of forming a sound judgment, expresses himself strongly to ns
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THE DESCENT OP MAN.
Part I.
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 Ins lower, though at the moment, stronger impulses or desires. This, as Mr. Gal ton 36 has remarked, is all the less surprising, as man has emerged from a state of barbarism within a comparatively recent period. After having yielded to some temptation we feel a sense of dissatisfaction, analogous to that felt from other un- satisfied instincts, called in this case conscience ; for we cannot prevent past images and impressions continually passing through our minds, and these in their weakened state we compare with the ever-present social instincts, or with habits gained in early youth and strengthened during our whole lives, perhaps inherited, so that they are at last rendered almost as strong as instincts. Looking to future generations, there is no cause to fear that the social instincts will grow weaker, and we may expect that virtuous habits will grow stronger, becoming perhaps fixed by inheritance. In this case the struggle between our higher and lower impulses will be less severe, and virtue will be triumphant.
Summary of the two last 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 lorm an artful plan to plunder a garden— though lie could use stones for fighting or for breaking open nuts,
effect Mr. Lecky (‘Hist, of Morals,’ vol. i extent to coincide
■ p. 143) seems to a certain
Ire l)* lf A bi™4 011 Hereditary Genius,’ 1S69, p. 349. remarks on f A^yh ( Primeval Man,’ 1SS9, p. 188) has some good remarks on the contest in man’s nature between right and wrong
The
Chap. III.
SUMMARY,
105
yet that the thought of fashioning a stone into a tool was quite beyond his scope. Still less, as he would admit, could he follow out a train ol metaphysical reasoning, or solve a mathematical problem, or reflect on God, ot admire a grand natural scene. Some apes, however, would probably declare that they could and did admire the beauty of the coloured skin and fur of their partners in marriage. They would admit, that though they could make other apes understand by cries some of their perceptions and simpler ■wants, the notion of expressing definite ideas by definite sounds had never crossed their minds. They might insist that they "'ere ready to aid their fellow-apes of the same troop in naany ways, to risk their lives for them, and to take charge of their orphans ; but they would be forced to acknowledge that disinterested love for all living crea- tures, the most noble attribute of man, was quite be- yond their comprehension.
Nevertheless the difference in mind between man and the higher animals, great as it is, is certainly one. of degree and not of kind. We have seen that the senses and intuitions, the various emotions and faculties, such as love, memory, attention, curiosity, imitation, mason, &c., of which man boasts, may bo found in an incipient, or even sometimes in a well-developed con- ation, in the lower animals. They are also capable of some inherited improvement, as we see in the domestic (l°g compared with the wolf or jackal. If it be main- fnined that certain powers, such as self-consciousness, "bs tract ion, &c., are peculiar to man, it may well be that these are the incidental results of other highly- ndvanced intellectual faculties; and these again are mainly the result of the continued use of a highly developed language. At what age does the new-born mfant possess the power of abstraction, or become self-
106
THE DESCENT OF MAN.
Part I.
conscious and reflect on its own existence ? We cannot answer ; nor can we answer in regard to the ascending organic scale. The half-art and half-instinct of lan- guage still bears the stamp of its gradual evolution. The ennobling belief in God is not universal with man ; and the belief in active spiritual agencies naturally fol- lows from his other mental powers. The moral sense perhaps affords the best and highest, distinction between man and the lower animals ; but I need not say any- thing on this head, as I have so lately endeavoured to shew that the social instincts, — the prime principle of man’s moral constitution 39 — with the aid of active intellectual powers and the effects of habit, naturally lead to the golden rule, “ As ye would that men should “do to you, do ye to them likewise;” and this lies at the foundation of morality.
In a future 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 this at least is possible ought not to be denied, when we daily see their development in every infant; and when we may trace a perfect grada- tion from the mind of an utter idiot, lower than that of the lowest animal, to the mind of a New ton.
" ‘ Tlie Thoughts of Marcus Aurelius,' &c., p. 139.
C»A.P. IV.
MANNER OP DEVELOPMENT.
107
CHAPTER IV.
On the Manner of Development of Man from some lower Form.
Variability of body and mind in man — Inheritance Causes of
variability — Laws of variation the same in man as in the lower animals — Direct action of the conditions ol life Effects of the increased use and disuse of parts— Arrested development — Re- version — Correlated variation — Rate of increase Checks to increase — Natural selection — Man the most dominant animal in the world — Importance ol his corporeal structure I he
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.
We have seen in the first chapter that the homological structure of man, his embryological development and the rudiments which he still retains, all declare in the plainest manner that he is descended from some lower form. The possession of exalted mental powers is no insuperable objection to this conclusion. In order that an ape-like creature should have been transformed into ^an, it is necessary that this early form, as well as 111 any successive links, should all have varied in mind aud body. It is impossible to obtain direct evidence on this head ; but if it can be shewn that man now varies -that his variations are induced by the same general °hUses, and obey the same general laws, as in the case °f the lower animals — there can be little doubt that the preceding intermediate links varied in a like banner. The variations at each successive stage of descent must, also, have been in some manner accumu- lated and fixed.
108
THE DESCENT OP MAN.
Part I.
The facts and conclusions to be given in this chapter relate almost exclusively to the probable means by which the transformation of man has been effected, as far as his bodily structure is concerned. The fol- lowing chapter will be devoted to the development of his intellectual and moral faculties. But the present discussion likewise bears on the origin of the different races or species of mankind, whichever term may he preferred.
It is manifest that man is now subject to much variability. No two individuals of the same race are quite alike. We may compare millions of faces, and each will be distinct. There is an equally great amount of diversity in the proportions and dimensions of the various parts of the body ; the length of the legs being one of the most variable points.1 Although in some quarters of the world an elongated skull, and in other quarters a short skull prevails, yet there is great diversity of shape even within the limits of the same race, as with the aborigines of America and South Australia, the latter a race “ probably as pure and “ homogeneous in blood, customs, and language as any “ in existence ” — and even with the inhabitants of so confined an area as the Sandwich Islands.2 An emi- nent dentist assures me that there is nearly as much diversity in the teeth, as in the features. The chief arteries so frequently run in abnormal courses, that it has been found useful for surgical purposes to calculate
1 ‘ Investigations in Military and Anthropolog. Statistics of American Soldiers,’ by B. A. Gould, 1869, p. 256.
2 With respect to the “ Cranial forms of the American aborigines, see Dr. Ail, ken Meigs in ‘ Pxoc. Aead. Nat. Sei.’ Philadelphia, Map 1866. On the Australians, see Huxley, in Lyell’s ‘ Antiquity of M»n> 1863, p. 87. On the Sandwich islanders, Prof. J. Wyman, ‘ Observa- tions on Crania,’ Boston, 1S08, p. 18.
Chap. IV.
MANNER OF DEVELOPMENT.
109
from 12,000 corpses how often each course prevails.3 The muscles are eminently variable : thus those of the foot were found by Prof. Turner4 not to be strictly alike in any two out of fifty bodies; and in some the deviations were considerable. Prof. Turner adds that the power of performing the appropriate movements must have been modified in accordance with the several deviations. Mr. J. Wood has recorded 5 the occurrence °f 295 muscular variations in thirty-six subjects, and in another set of the same number no less than 558 varia- tions, reckoning both sides of the body as one. In the last set, not one body out ol the thirty-six was found 11 totally wanting in departures from the standard de- “ seriptions of tire muscular system given in anatomical “ text-books.” A single body presented the extraordi- nary number of twenty-five distinct abnormalities. The sanre muscle sometimes varies in many ways : thus Trof. Macalister describes 0 no less than twenty distinct variations in the pedmaris accessorius.
The famous old anatomist, Wolff,7 insists that the internal viscera are more variable than the external parts: Nulla particula cst quee non aliter et aliter in dliis se habeat hominibus. He has even written a treatise °n the choice of typical examples of the viscera for ^presentation. A discussion on the beau-ideal ot tlie liver, lungs, kidneys, &c., as of the human face divine, s°unds strange in our ears.
The variability or diversity of the mental faculties *n men of the same race, not to mention the greater
‘ Anatomy of the Arteries,’ by B. Quain.
4 ‘ Transact. Royal Soc.’ Edinburgh, vol. xxiv. p. 175, 189.
* 1 Proc. Royal Soc.’ 18G7, p. 51-1 ; also 1868, p. 483, 524. There is a Previous paper, 1866, p. 229. b ‘ Rroc. R. Irish Academy,’ vol. x. 1868, p. 141.
7 ‘Act. Acad.,’ St. Petersburg, 1778, part ii. p. 217.
110
THE DESCENT OF MAN.
Part I.
differences between tlie men of distinct races, is so notorious that not a word need here be said. So it is with the lower animals, as has been illustrated by a few examples in the last chapter. All who have had charge of menageries admit this fact, and we see it plainly in our dogs and other domestic animals. Brehm especially insists that each individual monkey of those which he kept under confinement in Africa had its own peculiar disposition and temper : he mentions one baboon remarkable for its high intelligence ; and the keepers in the Zoological Gardens pointed out to me a monkey, belonging to the New World division, equally remark- able for intelligence. Rengger, also, insists on the di- versity in the various mental characters of the monkeys of the same species which he kept in Paraguay ; and this diversity, as he adds, is partly innate, and partly the result of the manner in which they have been treated or educated.6 * 8
I have elsewhere 9 so fully discussed the subject of Inheritance that I need here add hardly anything. A greater number of facts have been collected with respect to the transmission of the most trifling, as well as of the most important characters in man than in any of the lower animals ; though the facts are copious enough with respect to the latter. So in regard to mental qualities, their transmission is manifest in our dogs, horses, and other domestic animals. Besides special tastes and habits, general intelligence, courage, bad and good temper, &c., are certainly transmitted. With man we see similar facts in almost every family ; and we
6 Brehm, 1 Thierleben,’ B. i. s. 58, 87. Kengger, ‘ Saugethiere von
Paraguay,’ s. 57.
u ' Variation of Animals and Plants under Domestication,’ vol. n*
chap. xii.
Chap. iv.
MANNEB OF DEVELOPMENT.
Ill
How know through the admirable labours of Mr. G-alton 10 that genius, which implies a wonderfully complex com- bination of high faculties, tends to be inherited ; and, on the other hand, it is too certain that insanity and deteriorated mental powers likewise run in the same families.
With respect to the causes of variability we are in ail cases very ignorant ; but we can see that in man as in the lower animals, they stand in some relation with the conditions to which each species has been exposed during several generations. Domesticated animals vary more than those in a state of nature ; aud this is appa- rently due to the diversified and changing nature of their conditions. The different races of man resemble in this respect domesticated animals, and so do the individuals of the same race when inhabiting a very Wide area, like that of America. We see the influence °f diversified conditions in the more civilised nations, the members of which belong to different grades of rank mid follow different occupations, presenting a greater range of character than the members of barbarous nations. But the uniformity of savages has often been exaggerated, and in some cases can hardly be said to exist.11 It is nevertheless an error to speak of man, even if we look only to the conditions to which he has been subjected, as “ far more domesticated ” u than
10 ‘Hereditary Genius : an Inquiry into its Laws and Consequences,’ 1869.
11 Mr. Bates remarks (• The Naturalist on the Amazons,’ 1863, vol. ii. J>- 159), with respect to the Indians of the same S. American tribe, jno two of them were at all similar in the shape of the head; one ( man had an oval visage with fine features, and another was quite ( Mongolian in breadth and prominence of cheek, spread of nostrils,
aib(l obliquity of eyes.”
12 Blumenbach, 1 Treatises on Anthropolog.’ Eng. translate 1865, P- 205.
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THE DESCENT OP MAN.
Part l
any other animal. Some savage races, such as the Australians, are not exposed to more diversified con- ditions than are many species which have very wide ranges. In another and much more important re- spect, man differs widely from any strictly domesti- cated animal ; for his breeding has not been controlled, either through methodical or unconscious selection. No race or body of men has been so completely subjugated by other men, that certain individuals have been pre- served and thus unconsciously selected, from being in some way more useful to their masters. Nor have certain male and female individuals been intentionally picked out and matched, except in the well-known case of the Prussian grenadiers ; and in this case man obeyed, as might have been expected, the law of me- thodical selection ; for it is asserted that many tall men were reared in the villages inhabited by the grenadiers with their tall wives.
If we consider all the races of man, as forming a single species, his range is enormous ; but some separate races, as the Americans and Polynesians, have very wide ranges. It is a well-known law that widely-ranging species are much more variable than species with re- stricted ranges ; and the variability of man may with more truth be compared with that of widely-ranging species, than with that of domesticated animals.
Not only docs variability appear to be induced in man and the lower animals by the same general causes, but in both the same characters are affected in a closel) analogous manner. This has been proved in such fttH detail by Godron and Quatrefages, that I need here only refer to their works.13 Monstrosities, which gr®'
13 Godron, 1 De l’Espoce,’ 1859, tom. ii. livre 3. Quatrefages, 1 TTnite de l’Espece Humaine,’ 1861. Also Lectures on Anthropology, given in the ‘ Eevue des Cours Seientifiquos,’ 1866-18CS.
Chap. IV.
MANNER OF DEVELOPMENT.
113
duate into slight variations, are likewise so similar in man and the lower animals, that the same classifica- tion and the same terms can he used for both, as may be seen in Isidore Geoffrey St-IIilaire’s great work.14 This is a necessary consequence of the same laws of change prevailing throughout the animal kingdom. In my work on the variation of domestic animals, 1 have attempted to arrange in a rude fashion the laws of variation under the following heads -.—The direct and definite action of changed conditions, as shewn by all or nearly all the individuals of the same species varying in the same manner under the same circumstances. The effects of the long-continued uso or disuse of Parts. The cohesion of homologous parts. The vari- ability of multiple parts. Compensation of growth ; hut of this law I have found no good instances m the case of man. The effects of the mechanical pressure of °ne part on another ; as of the pelvis on the omnium of the infant in the womb. Arrests of development, leading to the diminution or suppression of parts. The reappearance of long-lost characters through reversion. And lastly, correlated variation. All these so-called laws apply equally to man and the lower animals ; and most of them even to plants. It would bo superfluous here to discuss all of them;15 but several are so im- portant for us, that they must be treated at consider- able length.
The direct and definite action of changed conditions - This is a most perplexing subject. It cannot be denied
14 ‘Hist. Gen. et Part, des Anomalies de ^Organisation,4 in three
volumes, tom. i. 1832. „ . L. ... ,
15 I have fully discussed these laws in my ‘Variation of Animals an<l Plants under Domestication/ vol. & chap. xxn* ant^ XX1L1, "*-• ** *
Durand has lately (1868) published a valuable essay ‘ De 1 Influence ^cs Milieux, &c/ He lays much stress on the nature of the soil.
VOL. L 1
] 14
THE DESCENT OF MAN.
Part h
that changed conditions produce some effect, and occa- sionally a considerable effect, on organisms of all kinds ; and it seems at first probable that if sufficient time were allowed this would be the invariable result. But I have failed to obtain clear evidence in favour of this conclusion ; and valid reasons may be urged on the other side, at least as far as the innumerable structures are concerned, which are adapted for special ends. There can, however, be no doubt that changed condi- tions induce an almost indefinite amount of fluctuating variability, by which the whole organisation is rendered in some degree plastic.
In the United States, above 1,000,000 soldiers, who served in the late war, were measured, and the States in which they were born and reared recorded.16 From this astonishing number of observations it is proved that local influences of some kind act directly on stature ; and we further learn that “ the State where the physical “ growth has in great measure taken place, and the State “ of birth, which indicates the ancestry, seem to exert “ a marked influence on the stature.” For instance it is established, “ that residence in the Western States, “ during the years of growth, tends to produce increase “ of stature.” On the other hand, it is certain that with sailors, their manner of life delays growth, as shewn “ by “ the great difference between the statures of soldiers and “ sailors at the ages of 17 and 18 years.” Mr. B. A. Gould endeavoured to ascertain the nature of the influences which thus act on stature ; but he arrived only at nega- tive results, namely, that they did not relate to climate, the elevation of the land, soil, nor even “ in any con- “ trolling degree ” to the abundance or need of the coni'
16 ‘ Investigations in Military and Anthrop. Statistics,’ &c. 1869, by B. A. Gould, p. 93, 107, 126, 131, 134.
Chap. IV.
MANNER OF DEVELOPMENT.
115
forts of life. This latter conclusion is directly opposed to that arrived at by Villcrnie from the statistics of the height of the conscripts in different parts of Trance. When we compare the differences in stature between the Polynesian chiefs and the lower orders within the same islands, or between the inhabitants ol the fertile volcanic and low barren coral islands of the same ocean,17 or again between the Tuegians on the eastern and western shores of their country, where the means of subsistence are very different, it 'is scarcely possible to avoid the conclusion that better food and greater comfort do in- fluence stature. But the preceding statements shew how difficult it is to arrive at any precise result. Dr. Beddoe has lately proved that, with the inhabitants ot Britain, residence in towns and certain occupations have a deteriorating influence on height ; and he infers that the result is to a certain extent inherited, as is likewise the case in the United States. Dr. Beddoe further believes that wherever a “ race attains its maximum ot “ physical development, it rises highest in energy and “ moral vigour.”18
Whether external conditions produce any otliei direct effect on man is not known. It might have been expected that differences of climate would have had a Marked influence, as the lungs and kidneys are brought into fuller activity under a low temperature, and the Bver and skin under a high one.lJ It was formerly thought that the colour of the skin and the eliaractei
17 For the Polynesians, see Prichard's ‘Physical Hist, of Mankind, pd. v. 1817, p. 115, 2S3. Also Godron, ‘He l’Espece,’ tom. ii. p. 289. There is also a remarkable difference in appearance between the closely- "hied Hindoos inhabiting the Upper Conges and Bengal ; see Elphin- stone’s * History of India,’ vol. i. p. 321.
18 ‘ Memoirs, Anthropolog. Soc.’ vol. iii- 18G7-G9, p. 561, 5C5, 567.
19 Dr. Brakenvidge, • Theory of Diathesis,’ ‘Medical Times,’ June 19 and July 17, 1869.
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THE DESCENT OF MAN.
Part I-
•of the hair were determined by light or heat ; and although it can hardly be denied that some effect is thus produced, almost all observers now agree that the effect has been very small, even after exposure during many ages. But this subject will be more properly discussed when we treat of the different races of man- kind. With our domestic animals there are grounds for believing that cold and damp directly affect the growth of the hair ; but I have not met with any evi- dence on this head in the case of man.
Effects of the increased Use and Disuse of Parts. — It is well known that use strengthens the muscles in the individual, and complete disuse, or the destruction of the proper nerve, weakens them. When the eye is destroyed the optic nerve often becomes atrophied. When an artery is tied, the lateral channels increase not only in diameter, but in the thickness and strength of their coats. When one kidney ceases acting from disease, the other increases in size and does double work. Bones increase not only in thickness, but ih length, from carrying a greater weight,20 Different occupations habitually followed lead to changed pro- portions in various parts of the body. Thus it was clearly ascertained by the United States Commission'1 that the legs of the sailors employed in the late war were longer by 0217 of an inch than those of the sol' diers, though the sailors were on an average shorter men ; whilst their arms were shorter by 1‘09 of an inch, and therefore out of proportion shorter in relation to
20 I have given authorities for these several statements in my ‘ Varia tion of Animals under Domestication,’ vol. ii. p. 297-300. Dr. J&eS®r; “ Ueber das Langenrvachstkum der Knochen,” ‘ Jenaischen Zeitschrif , B. v. Heft i.
21 ‘ Investigations,’ &c. By B. A. Gould, 1S69, p. 2S8.
Chap. IV.
MANNER OP DEVELOPMENT.
117
their lesser height. This shortness of the arms is apparently due to their greater use, and is an un- expected result; but sailors chiefly use their arms in pulling and not in supporting weights. The girth of the neck and the depth of the instep are greater, whilst the circumference of the chest, waist, and hips is less in sailors than in soldiers.
Whether the several foregoing modifications would become hereditary, if the same habits of life were fol- lowed during many generations, is not known, but is probable. Bengger* attributes the thin legs and thick arms of the Payaguas Indians to successive generations having passed nearly their whole lives in canoes, with their lower extremities motionless. Other writers have come to a similar conclusion in other analogous cases. According to Cranz,23 who lived for a long time with the Esquimaux, “ the natives believe that ingenuity and “ dextority in seal-catching (their highest art and virtue)
“ is hereditary ; there is really something in it, lor the “ son of a celebrated seal-catcher will distinguish him- “ self though he lost his father in childhood.” But in this case it is mental aptitude, quite as much as bodily structure, which appears to be inherited. It is asserted that the hands of English labourers are at birth larger than those of the gentry.24 From the correlation which exists, at least in some cases,25 between the development of the extremities and of the jaws, it is possi o la in those classes which do not labour much wit t eir hands and feet, the jaws would be reduced in size from this cause. That they are generally smaller m refined and civilised men than in hard-working men 01 savages,
22 ‘ Saugetbiere von Paraguay,’ 1830, s. 4.
23 ‘History of Greenland,’ Eng. translat. Ifb7, vol. i. p. 230.
24 ‘Intermarriage.’ By Alex. Walker, 1838, p. 377.
35 ‘ The Variation of Animals under Domestication,’ vol. i. p. 173.
118
THE DESCENT OF MAN.
Paet I.
is certain. But with savages, as Mr. Herbert Spencer 26 has remarked, the greater use of the jaws in chewing coarse, uncooked food, would act in a direct manner on the masticatory muscles and on the bones to which they are attached. In infants long before birth, the skin on the soles of the feet is thicker than on any other part of the body;27 and it can hardly be doubted that this is due to the inherited effects of pressure during a long series of generations.
It is familiar to every one that watchmakers and en- gravers are liable to be short-aighted, whilst men living much out of doors, and especially savages, are generally long-sighted. Short-sight anil long-sight certainly tend to be inherited. : I he inieriority ot Europeans, in com- parison with savages, in eye-sight and in the other senses, is no doubt the accumulated and transmitted effect of lessened use during many generations ■ for 1 lenggoi states that he has repeatedlv observed Euro- peans, who had been brought up and spent their whole lives with the wild Indians, who nevertheless did not equal them in the sharpness of their senses. The same naturalist observes that the cavities in the skull for the reception of the several sense-organs are larger in the American aborigines than in Europeans ; and this no doubt indicates a corresponding difference in the dimensions of the organs themselves. Blumenbaek has also remarked on the large size of the nasal cavities
26 c Principles 0f Biology,’ yol. i. p. 455.
77 Paget, ‘Lectures on Surgical Pathology, ’ vol. ii. 1853, p. 209.
28 ‘ The Variation of Animals under Domestication,’ vol. i. p. 8.
28 ‘Saugethiei'o von Paraguay,’ s. 8, 10. 1 have had good oppor- tunities tor observing the extraordinary power of eyesight in the huegntns. See also Lawrence (‘ Lectures on Physiology,’ &c., 1822, p. 404) on this samo subject. M. Giraud-Teulon has recently collected ( Kevue des Cours Scientifiques,’ 1870, p. 625) a large and valuable body ot evidence proving that the cause of sliort-sight, “ C’est le travail “ astsidu, de pres.’
Chap. IV.
MANNER OF DEVELOPMENT.
119
in the skulls of the American aborigines, and connects this fact with their remarkably acute power of sine . The Mongolians of the plains of Northern Asia, according to Pallas, have wonderfully perfect senses ; and I richard believes that the great breadth of their skulls across the zygomas follows from their highly-developed sense-
The Quechua Indians inhabit the lofty plateaux of Peru, and Alcide d’Orbigny states- that from con- tinually breathing a highly rarefied atmosphere they have acquired chests and lungs of extraordinary dimen- sions. The cells, also, of the lungs are larger and more numerous than ,in Europeans. These observations have been doubted; but Mr. D. Forbes _ carefully measured many Avmaras, an allied race, t'mg a height of between ten and fifteen thousand feet ; am he informs me32 that they differ conspicuously from the men of ah other races seen by him, m the circum- ference and length of their bodies. In his table of measurements, the stature of each man is taken at 1000, and tie other measurements are reduced to this standard. It is here seen that the extended arms of the Avmaras are shorter than those of Europeans, and much shorter than those ot Negroes. 0 egs aie likewise shorter, and they present this remarkable i pecu- liarity, that in every Aymara measured the lemur is actually shorter Am the tibia. Oh ah average the
length Ot the femur to that el the tibia is a» - to 252; whilst in two Europeans measured at xhe same
3° Prichard, • Pkys. Hist, of Mankind,’ on the authority of Blurncn- bach, vol. i. 1851, p. 311 ; for the statement by I alias, vol. tv. 184 , p. 407.
3I' Quoted by Prichard, 1 Researches into the Pliys. Hist, of Man-
^MthForw' "valuable paper is now published in the ‘Journal of the Ethnological Soc. of London,’ new senes, vol. n. 1870, p. 193.
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THE DESCENT OF MAN.
Part I.
time, the femora to the tibiae were as 244 to 230 ; and in three Negroes as 258 to 241. The humerus is like- wise shorter relatively to the forearm. This shortening of that part of the limb which is nearest to the body, appears to be, as suggested to me by Mr. Forbes, a case of compensation in relation with the greatlv increased length of the trunk. The Aymaras present some other singular points of structure, for instance, the very small projection of the heel.
These men are so thoroughly acclimatised to their cold and lofty abode, that when formerly carried down by the (Spaniards to the low Eastern plains, and when now tempted down by high wages to the gold-washings, they suffer a frightful rate oi mortality. Nevertheless Mr. Forbes found a few pure families which had sur- vived during two generations ; and lie observed that they still inherited their characteristic peculiarities. But it was manifest, even without measurement, that these peculiarities had all decreased ; and on measure- ment their bodies were found not to be so much elon- gated as those of the men ou the high plateau ; whilst their femora had become somewhat lengthened, as had their tibia; but in a less degree. The actual measure- ments may be seen by consulting Mr. Forbes’ memoir. From these valuable observations, there can, I think, be no doubt that residence during many generations at a great elevation tends, both directly and indirectly, to induce inherited modifications in the proportions of the body.33
Although man may not have been much modified during the latter stages of his existence through the
33 Dr. Wilckens (‘ Landwirthschaft. Woelienblatt,’ No. 10, 1S69) has lately published an interesting essay shewing how domestic animals, which live in mountainous regions, have their frames modified.
Ciiap IV.
MA.NNER OF DEVELOPMENT.
121
increased or decreased use of parts, tire facts now given shew that his liability in this respect has not been lost ; and we positively know that the same law holds good with the lower animals. Consequently we may infer, that when at a remote epoch the progenitors of man were in a transitional state, and were changing from quadrupeds into bipeds, natural selection would probably have been greatly aided by the inherited effects of the increased or diminished use of the different parts of the body.
Arrests of Development.— Arrested development differs from arrested growth, as parts in the former state con- tinue to grow whilst still retaining their early condition. Various monstrosities come under this head, and some are known to be occasionally inherited, as a cleft-palate. It will suffice for our purpose to refer to the arrested brain-development of microcephalous idiots, as described in Vogt’s great memoir.3' Their skulls are smaller, and the convolutions of the brain are less complex than in normal men. The frontal sinus, or the projection over the eye-brows, is largely developed, and the jaws are prognathous to an “effrayant ” degree ; so that these idiots somewhat resemble the lower types of mankind, lheir intelligence and most of their mental faculties are extremely feeble. They cannot acquire the power of speech, and are wholly incapable of prolonged attention but are much given to imitation. They are strong am remarkably active, continually gamboling and jumping about, and making grimaces. They often ascend stairs on all-fours ; and are curiously fond of climbing, up furniture or trees. We are thus reminded of the delight
84 ‘Memoire sur les Microcephales,’ 1S67, p. 50, 125, 169, 171, 181- 198.
122
THE DESCENT OF MAN.
Part I.
shewn by almost all boys in climbing trees ; and this again reminds ns how lambs and kids, originally alpine animals, delight to frisk on any hillock, however small.
Reversion. — Many of the cases to be here given might have been introduced under the last heading. Whenever a structure is arrested in its development, but still continues growing until it closely resembles a corresponding structure in some lower and adult member of the same group, we may in one sense consider it as a case of reversion. Ihe lower members in a group give us some idea how the common progenitor of the group was probably constructed ; and it is hardly credible that a part arrested at an early phase of embryonic develop- ment should be enabled to continue growing so as ulti- mately to perform its proper function, unless it had acquired this power of continued growth during some earlier state of existence, when the present exceptional or arrested structure was normal. The simple brain of a microcephalous idiot, in as far as it resembles that of an ape, may in this sense be said to offer a case of reversion. There are other cases which come more stiictly under oui present heading of reversion. Oertain structures, regularly occurring in the lower members of the group to which man belongs, occasionally make their appearance in him, though not found in the normal human embryo; or, if present in the normal human embryo, they become developed in an abnormal manner, though this manner of development is proper to the lower members of the same group. These remarks will be rendered clearer by the following illustrations.
In various mammals the uterus graduates from a double organ with two distinct orifices and two passages, as in the marsupials, into a single organ, showing no signs of doubleness except a slight internal fold, as in
Chap. IV.
MANNER OF DEVELOPMENT.
123
tlie higher apes and man. The rodents exhibit a per- tect series of gradations between these two extreme states. In all mammals the uterus is developed from two simple primitive tubes, the inferior portions of which form the cornua; and it is in the words of Dr. Farre “ by the coalescence of the two cornua at “ their lower extremities that the body of the uterus is “formed in man ; while in those animals in which no “ middle portion or body exists, the cornua remain un- “ united. As the development of the uterus proceeds,
“ the two cornua become gradually shorter, until at “length they are lost, or, as it were, absorbed into the “body of tlie uterus.” The angles of the uterus are still produced into cornua, even so high in the scale as in the lower apes, and their allies the lemurs.
Now in women anomalous cases are not very infre- quent, in which the mature uterus is furnished with cornua, or is partially divided into two organs; and such cases, according to Owen, repeat “ the grade of con- “ centrative development,” attained by certain rodents. Here perhaps we have an instance of a simple arrest ol embryonic development, with subsequent growth and perfect functional development, for either side of the partially double uterus is capable of performing the proper office of gestation. In other and rarer cases, two distinct uterine cavities are formed, each having its proper orifice and passage.36 No such stage is passed through during the ordinary development of the embryo, m ul it is difficult to believe, though perhaps not im- possible, that the two simple, minute, primitive tubes ®°nld know how (if such an expression may be used) to
3i See Dr. A. Farre’s well-known article in the 1 Cyclop, of Anat. fyd Pliys.’ vol. v. 1859, p. 642. Owen ‘ Anatomy of Vertebrates,’ vol. fit 1868, p. 687. Prof. Turner in ‘ Edinburgh Medical Journal,’ Feb. 1865.
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grow into two distinct uteri, each with a well-constructed orifice and passage, and each furnished with numerous muscles, nerves, glands and vessels, if they had not formerly passed through a similar course of develop- ment, as in the case of existing marsupials. No one will pretend that so perfect a structure as the abnormal double uterus in woman could he the result of mere chance. But the principle of reversion, by which long- lost dormant structures are called back into existence, might serve as the guide for the full development ol the organ, even after the lapse of an enormous interval of time.
Professor Canestrini,36 after discussing the foregoing and various analogous cases, arrives at the same con- clusion as that just given. He adduces, as another instance, the malar bone, which, in some of the Quad- rumana and other mammals, normally consists of two portions. This is its condition in the two-months-old human foetus ; and thus it sometimes remains, through arrested development, in man when adult, more especially in the lower prognathous races. Hence Canestrini con- cludes that some ancient progenitor of man must have possessed this bone normally divided into two portions, which subsequently became fused together. In man the frontal bone consists of a single piece, but in the embryo and in children, and in almost all the lower mammals, it consists of two pieces separated by a dis- tinct suture. This suture occasionally persists, more or less distinctly, in man after maturity, and more fre-
K ‘ Annuario della Soc. dei Natnralisti in Modena,’ 1S67, p- S3. Prof. Canestrini gives extracts on this subject from various authorities. Laurillard remarks, that as he lias found a complete similarity in the form, proportions, and connexion of the two malar bones in several human subjects and in certain apes, ho cannot consider this disposition of the parts as simply accidental.
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quently in ancient, than in recent crania, especially as Canestrini has observed in those exhumed from the Drift and belonging to the brachycephalic type. Here again he conies to the same conclusion as in the ana- logous case of the malar bones. In this and other instances presently to be given, the cause of ancient races approaching the lower animals in certain cha- racters more frequently than do the modern races, appears to be that the latter stand at a somewhat greater distance in the long line of descent from their early semi-human progenitors.
Various other anomalies in man, more or less analo- gous with the foregoing, have been advanced by dif- ferent authors37 as cases of reversion; but these seem hot a little doubtful, for we have to descend extremely low in the mammalian series before we find such struc- tures normally present.88
17 A whole series of cases is given by Isid. Geoffroy St.-Hilaire,
1 Hist, des Anomalies,’ tom. iii. p. 437. _
38 In my ‘ Variation of Animals under Domestication (vol. n. p. oi)
I attributed the not very rare cases of supernumerary nmnnnse in Women to reversion. I was led to tills as a probable conclusion, by the additional mammas being generally placed symmetrically on the breast and more especially from one case, in which a single efficient mamma occurred in the inguinal region of a woman, the daughter ot another Woman with supernumerary mamma). But Prof. Preyer v er vamp run das Dascin,' 1869, s, 45) states that mammas erratic® have been known to occur in other situations, even on the back ; so that the lurce of mv argument is greatly weakened or perhaps quite
With much hesitation I, in the same work (vol. u. p. 1-), attributed the frequent cases of polydact.ylisni in men to revcisum. "a Par 7 led to this through Prof. Owen’s statement, that some ot the Ichthy- optorygia possess more than five digits, and there ore, as I supposed, had retained a primordial condition; but after reading Piof._ Gegcnbaur s Paper (‘ Jcuaiseheu Zeitsckrift,’ B. v. Heft 3, s. 341), who is the highest authority in Europe on such a point, and who disputes Owen s con- clusion, I see that it is extremely doubtful whether supernumerary digits can thus be accounted for. It was the fact that such digits not only frequently occur and are strongly inherited, but have the power of regrowtli after amputation, like the normal digits of the lower verte-
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THE DESCENT OP MAN.
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In man the canine teeth are perfectly efficient instru- ments for mastication. But their true canine character, as Owen39 remarks, “ is indicated by the conical form “ of the crown, which terminates in an obtuse point, is “ convex outward and flat or sub-concave within, at the “ base of which surface there is a feeble prominence. “ The conical form is best expressed in the Melanian “ races, especially the Australian. The canine is more “ deeply implanted, and by a stronger fang than the “ incisors.” Nevertheless this tooth no longer serves man as a special weapon for tearing his enemies or prey it may, therefore, as far as its proper function is con- cerned, be considered as rudimentary. In every large collection of human skulls some may be found, as Haekel40 observes, with the canine teeth projecting con- siderably beyond the others in the same manner, but in a less degree, as in the anthropomorphous apes. In these cases, open spaces between the teeth in the one jaw are left for the reception of the canines belonging to the opposite jaw. An interspace of this kind in a Kaffir skull, figured by Wagner, is surprisingly wide.41 Considering how few ancient skulls have been examined in comparison with recent skulls, it is an interesting fact that in at least three cases the canines project largely ; and in the Naulette jaw they are spoken of as enormous.42
brata, that cliiclly led me io the above conclusion. This extraordinary fact of their regrowth remains inexplicable, if the belief in reversion to some extremely remote progenitor must be rejected. I cannot, how- ever, follow Prof. Gegenbaur in supposing that additional digits could not reappear through reversion, without at the same time other parts of the skeleton being simultaneously and similarly modified ; for single characters often reappear through reversion.
30 ‘ Anatomy of Vertebrates,’ vol. iii. ISOS, p, 323.
40 ‘ Generelle Mnrphologie, ' I860, B. ii. s. civ.
44 Carl Vogt’s ‘Lectures on Man,’ Eng. trnnslat. 1804, p. 151.
4_ C. Carter Blake, on a jaw from I. a Naulette, ‘ Anthropology Review,’ 1807, p. 2115. Schaaft'hausen, ibid. 1808, p. 420.
chap. IV.
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The males alone of the anthropomorphous apes have their canines fully developed ; but in the female gorilla, and in a less degree in the female orang, these teeth Project considerably beyond, the others; therefore the tact that women sometimes have, as I have been assured, considerably projecting canines, is no serious objection to the belief that their occasional great development in 'can is a case of reversion to an ape-like progenitor. He who rejects with scorn the belief that the shape of bis own canines, and their occasional great development in other men, are due to our early progenitors having been provided with these formidable weapons, will pro- bably reveal by sneering the line of his descent. For though he no longer intends, nor lias the power, to use these teeth as weapons, he will unconsciously retract his snarling muscles” (thus named by Sir 0. Bell)43 so as t° expose them ready for action, like a dog prepared to
fight.
Many muscles are occasionally developed in man, 'vhich are proper to the Quadrumana or other mam- mals. Professor Vlacovich44 examined forty male sub- lets, and found a muscle, called by him the ischio- Pubie, in nineteen of them ; in three others there was a ligament which represented this muscle ; and in the Remaining eighteen no trace of it. Out of thirty female subjects this muscle was developed on both sides in only tw°, but in three others the rudimentary ligament was Present. This muscle, therefore, appears to be much 1110 1-e common iu the male than in the leiuale sex ; and °u the principle of the descent of man lrom some lower i°rm, its presence can be understood ; for it has been detected iu several of the lower animals, and iu all of
‘Tte Anatomy of Expression,’ 1844, p. 110, 131.
Quoted by Prof. Canestrini in the 1 Annuario,’ &c., 1 8G7, p. 90.
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these it serves exclusively to aid the male in the act of reproduction.
Mr. J. Wood, in bis valuable series of papers,45 has minutely described a vast number of muscular varia- tions in man, which resemble normal structures in the lower animals. Looking only to the muscles which closely resemble those regularly present in our nearest allies, the Quadrumana, they are too numerous to be here even specified. In a single male subject, having a strong bodily frame and well-formed skull, no less than seven muscular variations were observed, all of which plainly represented muscles proper to various kinds of apes. This man, for instance, had on both sides of his neck a true and powerful “ levator clavi- cultv ,” such as is found in all kinds of apes, and which is said to occur in about one out of sixty human sub- jects.45 Again, this man had “a special abductor of “ the metatarsal bone of the fifth digit, such as Pro- “ fessor Huxley and Mr. Flower have shewn to exist “ uniformly in the higher and lower apes.” The hands and arms of man are eminently characteristic structures, but their muscles are extremely liable to vary, so as to resemble the corresponding muscles in the lower ani- mals.47 Such resemblances are either complete and per-
45 These papers deserve careful study by any one who desires to learn how frequently our muscles vary, and in varying come to resemble those of tho Quadrumana. The following references relate to the few point* touched on in my text : Proo. Royal Soc. vol. xiv. 1865, p. 379-384 , vol. xv. 1866, p. 241, 242 ; vol. xv. 1S67, p. 544 ; vol. xvi. 18CS, p. 524. 1 may here add that Dr. Murie and Mr. St. George Mivnrt have shewn in their Memoir on the Lomuroidea (‘Transact. Zoolog. Soc.’ vol- vn' 1869. p. 96), how extraordinarily variable some of the muscles are m these animals, tho lowest members of the Primates. Gradations, als°i in the muscles lending to structures found in animals still lower in the scale, are numerous in the Lemuroidea.
48 Prof. Maculistcr in ‘Proe. R. Irish Academy,’ vol. x. 1S6S, p. 1-'*'
47 Prof. Maealiater (ibid. p. 121) has tabulated his observations, an finds that muscular abnormalities arc most frequent in the forearms secondly in the face, thirdly in the foot, &c.
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feet or imperfect, yet in this latter case manifestly ol a transitional nature. Certain variations are more com- mon in man, and others in woman, without our being- able to assign any reason. Mr. "Wood, after describing numerous cases, makes the following pregnant remark :
“ Notable departures from the ordinary type of the “ muscular structures run in grooves or directions, which “ must be taken to indicate some unknown factor, of “ much importance to a comprehensive knowledge of “ general and scientific anatomy.’ 48
That this unknown factor is reversion to a former state of existence may be admitted as in the highest degree probable. It is quite incredible that a man should through mere accident abnormally resemble, in no less than seven of his muscles, certain apes, if there bad been no genetic connection between them. On the other hand, if man is descended from some ape-like creature, no valid reason can be assigned why certain muscles should not suddenly reappear after an interval of many thousand generations, in the same manner as with horses, asses, and mules, dark-coloured stripes suddenly reappear on the legs and shoulders, after an interval of hundreds, or more probably thousands, ot generations.
These various cases of reversion are so closely related
48 The Rev. Dr. Haughton, after giving (‘Proc. K. Irish Academy, June 27, 1S64, p. 715) a remarkable case of variation in the human fetor poOieii longue, adds, “This remarkable example shews that man * hiay sometimes possess the arrangement of tendons 01 thumb and “ fingers characteristic of the macaque; but whether such a case should He regarded as a macaque passing upwards into a man, or a man Passing downwards into a macaque, or ns a congenital freak of ‘ nature, I cannot undertake to say.” It is satisfactory to hear so napahle an anatomist, and so embittered an opponent ot evolutionism, admitting even the possibility of either of his first propositions. Prof, maealister has also described (‘Proe. E. Irish Acad.’ vol. x. 1864, p. J.38) variations in the flexor poUiois lonrjus, remarkable from their rela- lons to the same urusclo in the Quadrumana.
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to those of rudimentary organs given in the first chapter, that many of them might have been indifferently intro- duced in either chapter. Thus a human uterus furnished with cornua may be said to represent in a rudimentary condition the same organ in its normal state in certain mammals. Some parts which are rudimental in man, as the os coccyx in both sexes and the mammae in the male sex, are always present ; whilst others, such as the supracondyloid foramen, only occasionally appear, and therefore might have been introduced under the head of reversion. These several reversionary, as well as the strictly rudimentary, structures reveal the de- scent of man from some lower form in an unmistakeable manner.
■ Correlated Variation. — In man, as in the lower ani- mals, many structures are so intimately related, that when one part varies so does another, without our being able, in most cases, to assign any reason. We cannot say whether the one part governs the other, or whether both are governed by some earlier developed part. Various monstrosities, as I. Geoffroy repeatedly insists, are thus intimately connected. Homologous structures are par- ticularly liable to change together, as we see on the opposite sides of the body, and in the upper and lower extremities. Meckel long ago remarked that when the muscles of the arm depart from their proper type, they almost always imitate those of the leg ; and so conversely with the muscles of the legs. The organs of sight and hearing, the teeth and hair, the colour of the skin and hair, colour and constitution, are more or less correlated.48 Professor Sehaaffhausen first drew attention to the rela-
45 The authorities for these several statements are given in my Variation of Animals under Domestication,’ vol. ii. p. 320-335.
Chap. IV.
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tion apparently existing between a muscular frame and strongly-pronounced supra-orbital ridges, which are so characteristic of the lower races of man.
Besides the variations which can bo grouped with more or less probability under the foregoing heads, there is a large class of variations which may be provi- sionally called spontaneous, for they appear, owing to our ignorance, to arise without any exciting cause. It can, however, be shewn that such variations, whether con- sisting of slight individual differences, or of strongly- marked and abrupt deviations of structure, depend much more on the constitution ol the organism than on the nature of the conditions to which it has been subjected.50
Bate of Increase. — Civilised populations have been known under favourable conditions, as in the United States, to double their number in twenty-five years; and according to a calculation by Euler, this might occur in a little over twelve years.51 At the former rate the present population of the United States, namely, thirty millions, would iu 657 years cover the whole terraqueous globe so thickly, that four men would have to stand on each square yard of surface. The primary °r fundamental check to the continued increase of man is the difficulty of gaining subsistence and of living in comfort. We may infer that this is the case from what "'e see, for instance, in the United States, where subsist- ence is easy and there is plenty of room. If such means "ere suddenly doubled in Great Britain, our number "'Quid be quickly doubled. With civilised nations the
50 This whole subject has been discussed in chap, xsiii. vol. ii. of ®y ‘ Variation of Animals and Plants under Domestication.’
51 See the ever memorable ‘ Essay on the Principle of Population,’ by the Kev. T. Malthus, vol. i. 1826, p. G, 517.
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above primary check acts chiefly by restraining mar- riages. The greater death-rate of infants in the poorest classes is also very important ; as well as the greater mortality at all ages, and from various diseases, of the inhabitants of crowded and miserable houses. The effects of severe epidemics and wars are soon counter- balanced, and more than counterbalanced, in nations placed under favourable conditions. Emigration also comes in aid as a temporary check, but not to any great extent with the extremely poor classes.
There is reason to suspect, as Malthus has remarked, that the reproductive pow’er is actually less in barbarous than in civilised races. We know nothing positively on this head, for with savages no census has been taken ; but from the concurrent testimony of missionaries, and of others who have long resided with such people, it appears that their families are usually small, and large ones rare. This may be partly accounted for, as it is believed, by the women suckling their infants for a pro- longed period ; but it is highly probable that savages, who often suffer much hardship, and wflio do not obtain so much nutritious food as civilised men, would be actually less prolific. I have shewn in a former work,52 that all our domesticated quadrupeds and birds, and all our cultivated plants, are more fertile than the corre- sponding species in a state of nature. It is no valid objection to this conclusion that animals suddenly supplied with an excess of food, or when rendered very fat, and that most plants when suddenly removed from very poor to very rich soil, are rendered more or less sterile. We might, therefore, expect that civilised men, who in one sense are highly domesticated, would
58 ‘ Variation of Animals and Plants under Domestication,’ vol. in p. 111-113, 163.
Chap. IV.
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be more prolific than wild men. It is also probable that the increased fertility of civilised nations would become, as with our domestic animals, an inherited character: it is at least known that with mankind a tendency to produce twins runs in families.53
Notwithstanding that savages appear to be less pro- lific than civilised people, they would no doubt rapidly increase if their numbers were not by some means rigidly kept down. The Santali, or hill-tribes of India, have recently afforded a good illustration ot this fact , for they have increased, as shewn by Mr. Hunter,54 at an extraordinary rate since vaccination has been introduced, other pestilences mitigated, and war sternly repressed. This increase, however, would not have been possible had not these rude people spread into the adjoining districts and worked for hire. Savages almost always marry ; yet there is some prudential restraint, for they do not commonly many at the earliest possible age. The young men are often required to show that they can support a wife, and they generally have first to earn the price with which to purchase her trom her Parents. With savages the difficulty of obtaining sub- sistence occasionally limits their number in a much more direct manner than with civilised people, for all tribes periodically suffer from severe famines. At such times savages are forced to devour much bad food, and their health can hardly fail to be injured. Many accounts have been published ot their protruding sto- machs and emaciated limbs after and during famines. I hey are then, also, compelled to wander much about, and their infants, as I was assured in Australia, perish
M Mr. Sedgwick, ‘British and Foreign Medico-Chirurg. Review,’ July, 1863, p. 170.
51 1 The Annals of Rural Bengal,’ by W. W . Hunter, 1S68, p. 259.
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in large numbers. As famines are periodical, depending chiefly on extreme seasons, all tribes must fluctuate in number. They cannot steadily and regularly increase, as there is no artificial increase in the supply of food. Savages when hardly pressed encroach on each other’s territories, and war is the result ; but they are indeed almost always at war with their neighbours. They are liable to many accidents on land and water in their search for food ; and in some countries they must suffer much from the larger beasts of prey. Even in India, districts have been depopulated by the ravages of tigers.
Malthus has discussed these several checks, but he does not lay stress enough on what is pjrobably the most important of all, namely infanticide, especially of female infants, and the habit of procuring abortion. These practices now prevail in many quarters of the world, and infanticide seems formerly to have prevailed, as Mr. M'Lennan 55 has shewn, on a still more extensive scale. These practices appear to have originated in savages recognising the difficulty, or rather the impos- sibility of supporting all the infants that are born- Licentiousness may also be added to the foregoing checks ; but this does not follow from failing means of subsistence ; though there is reason to believe that in some cases (as in Japan) it has been intentionally encouraged as a means of keeping down the population.
If we look back to an extremely remote epoch, before man bad arrived at the dignity of manhood, be would have been guided more by instinct and less by reason than are savages at the present time. Our early semi- human progenitors would not have practised infanticide, for the instincts of the lower animals are never so per- verted as to lead them regularly to destroy their own
55 1 Primitive Marriage,’ 1S65.
Chap. IV. MANNER OF DEVELOPMENT. lot)
offspring. There would have been no prudential re- straint from marriage, and the sexes would have freely united at an early age. Hence the progenitors of man would have tended to increase rapidly, but checks of some kind, either periodical or constant, must have kept down their numbers, even more severely than with existing savages. What the precise nature of these checks may have been, we cannot say, any more than with most other animals. We know that horses and cattle, which are not highly prolific animals, when first turned loose in South America, increased at an enormous rate. The slowest breeder of all known animals, namely the elephant, would in a few thousand years stock the whole world. The increase of every species of monkey must be checked by some means; but not, as Brehm remarks, by the attacks of beasts of prey. No one will assume that the actual power of reproduction in the wild horses and cattle ol America, was at thst in any sensible degree increased ; or that, as each district became fully stocked, this same power was diminished. No doubt in this case and in all others, many checks concur, and different checks under different circum- stances ; periodical dearths, depending on unfavourable seasons, being probably the most important of all. 1 0 it will have been with the early progenitors of man.
Natural Selection.— We have now seen that man is Variable in body and mind; and that the variations are induced, either directly or indirectly, by the same general causes, and obey the same general laws, as with the lower animals. Man has spread widely ovei the face of the earth, and must have been exposed, during ids incessant migrations,60 to the most diversified con-
56 See some good remarks to this effect by W. Stanley Jevons, “ A Deduction from Darwin’s Theory,” 1 Nature,’ 1869, p. 231.
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THE DESCENT OF MAN.
Part I.
ditions. The inhabitants of Tierra del Fuego, the Cape of Good Hope, and Tasmania in the one hemisphere, and of the Arctic regions in the other, must have passed through many climates and changed their habits many times, before they reached their present homes.57 The early progenitors of man must also have tended, like all other animals, to have increased beyond their means of subsistence; they must therefore occasionally have been exposed to a struggle for existence, and consequently to the rigid law of natural selection. Beneficial variations of all kinds will thus, either occasionally or habitually, have been preserved, and injurious ones eliminated. I do not refer to strongly-marked deviations of structure, which occur only at long intervals of time, but to mere individual differences. We know, for instance, that the muscles of our hands and feet, which determine our powers of movement, are liable, like those of the lower animals,58 to incessant variability. If then the ape-like progenitors of man which inhabited any district, espe- cially one undergoing some change in its conditions, were divided into two equal bodies, the one half which in- cluded all the individuals best adapted by their powers of movement for gaining subsistence or for defending themselves, would on an average survive in greater number and procreate more offspring than the other and less well endowed half.
Man in the rudest state in which he now exists is the most dominant animal that has ever appeared on the earth. He has spread more widely than any
57 Latham, ‘ Man and his Migrations,’ 1851, p. 135.
5S Messrs. Mime and Mivart in their “ Anatomy of the Lemuroidea” (‘ Transact. Zoolog. Soc.’ vol. vii. 1869, p. 96-98) say, "* some muscles “ are so irregular in their distribution that they cannot be well classed “ in any °f the above groups.” These muscles differ even on the oppo- site sides of the same individual.
Chap. IV.
MANNER OF DEVELOPMENT.
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other highly organised form ; and all others have yielded before him. He manifestly owes this immense superiority to his intellectual faculties, his social habits, which lead him to aid and defend his fellows, and to his corporeal structure. The supreme importance of these characters has been proved by the final arbitra- ment of the battle for life. Through his powers of in- tellect, articulate language has been evolved; and on this his wonderful advancement has mainly depended. He has invented and is able to use various weapons, tools, traps, &c., with which he defends himself, hills or catches prey, and otherwise obtains food. He has made rafts or canoes on which to fish or cross over to neigh- bouring fertile islands. He has discovered the art of making fire, by which hard and stringy roots can be rendered digestible, and poisonous roots or herbs in- nocuous. This last discovery, probably the greatest, excepting language, ever made by man, dates from before the dawn of history. These several inventions, 1 iy which man in the ruoest state has become so pre- eminent, are the direct result of the development of bis powers of observation, memory, curiosity, imagina- tion, and reason. I cannot, therefore, understand how it is that Mr. Wallace69 maintains, that “natural selec-
‘ Quarterly Review,’ April, 1869, p. 392. This subject is more fully discussed in Mr. Wallace’s ‘ Contributions to the Theory of Natural Selection,’ 1870, in which all the essays referred to m this work are republished. The ‘Essay on Man’ has been ably criticised by Prol. Claparfedc, one of the most distinguished zoologists m Europe, m an article published in the ‘ Bibhotheque Universelle, June, 1870. The remark quoted in my test will surprise every one who has read Mr. Wallace’s celebrated paper on ‘The Origin of Human Paces deduced from the Theory' of Natural Selection, originally published in the ‘ Anthropological Keviow,’ May, 1864, p. clviii. I cannot here resist quoting a most just remark by Sir J. Lubbock (‘Prehistoric Times,’ 1865, p. 179 ,i in reference to this paper, namely, that Mr. Wallace, “with characteristic unselfishness, ascribes it (/.e. the idea of
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THE DESCENT OF MAN.
Part I-
“ tion could only have endowed tlie savage with a brain “ a little superior to that of an ape.”
Although the intellectual powers and social habits of man are of paramount importance to him, we must not underrate the importance of his bodily structure, to which subject the remainder of this chapter will be devoted. The development of the intellectual and social or moral faculties will be discussed in the follow ing chapter.
Even to hammer with precision is no easy matter, as every one who has tried to learn carpentry will admit. To throw a. stone with as true an aim as can a Fuegian in defending himself, or in killing birds, requires the most consummate perfection in tire correlated action of the muscles of the hand, arm, and shoulder, not to mention a fine sense of touch. In throwing a stone or spear, and in many other actions, a man must stand firmly on his feet ; and this again demands the perfect coadaptation of numerous muscles. To chip a flint into the rudest tool, or to form a barbed spear or hook from a bone, demands the use of a perfect hand ; for, as a most capable judge, Mr. Schoolcraft,60 remarks, the shaping fragments of stone into knives, lances, or arrow-heads, shews “ extra* “ ordinary ability and long practice.” We have evidence of this in primeval men having practised a division of labour; each man did not manufacture his own flint tools or rude pottery ; but certain individuals appear to have devoted themselves to such work, no doubt re- ceiving in exchange the produce of the chase. Archaeo- logists are convinced that an enormous interval of time
“ natural selection) unreservedly to Mr, Darwin, allhough, as is well “ known, he struck out tho idea independently, and published it, “ though not with the same elaboration, at tho same time.”
60 Quoted by Mr. Lawson Tait in his “ Law of Natural Selection,” — ‘Dublin Quarterly Journal of Medical Science,’ Feb. 1S69. Dr. Keller is likewise quoted to the same effect.
Chap. IV.
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139
elapsed before our ancestors thought of grinding chipped flints into smooth tools. A man-like animal who pos- sessed a hand and arm sufficiently perfect to throw a stone with precision or to form a flint into a rude tool, could, it can hardly be doubted, with sufficient practice make almost anything, as far as mechanical skill alone is concerned, which a civilised man can make. The structure of the hand in this respect may be compared with that of the vocal organs, which m the apes are used for uttering various signal -cries, or, as m one spe- cies, musical cadences; but in man closely similar vocal organs have become adapted through the inherited effects of use for the utterance of articulate language.
Turning now to the nearest allies of man, and there- fore to the best representatives of our early progenitors, We find that the hands in the Quadrumaua are con- structed on the same general pattern as in us, but are far less perfectly adapted for diversified uses. Their hands do not serve so well as the feet oi a dog for loco- motion ; as may be seen in those monkeys which walk on the outer margins of the palms, or on the backs of their bent fingers, as in the chimpanzee and orang.1'' Their hands, however, are admirably adapted for climb- ing trees. Monkeys seize thin branches or Topes, with the thumb on one side and the fingers and palm on the other side, in the same manner as we do. icy can thus also carry rather large objects, such as the week of a bottle, to their mouths. Baboons turn over stones and scratch up roots with their hands. They seize nuts, insects, or other small objects with the thumb in opposition to the fingers, and no doubt they thus extract eggs and the young from the nests of flirds. American monkeys beat tbe wild oranges on the
61 Owen, 4 Anatomy of Vertebrates,’ vol. iii. p. /I.
140
THE DESCENT OF HAN.
Part !■
branches until the rind is cracked, and then tear it off with the fingers of the two hands. Other monkeys open mussel-shells with the two thumbs. With their fingers they pull out thorns and burs, and hunt for each other’s parasites. In a state ol nature they break open hard fruits with the aid of stones. They roll down stones or throw them at their enemies ; nevertheless, they perform these various actions clumsily, and they are quite unable, as I have myself seen, to throw a stone with precision.
It seems to me far from true that because “ objects “ are grasped clumsily ” by monkeys, “ a much less
specialised organ of prehension ” would have served them62 as well as their present hands. On the con- i' 1 1 try, I see no reason to doubt that a more perfectly constructed hand would have been an advantage to them, provided, and it is important to note this, that their hands had not thus been rendered less well adapted for climbing trees. We may suspect that a perfect hand would have been disadvantageous tor climbing; as the most aiboieal monkeys in the world, namely Ateles in America and Hylobates in Asia, either have their thumbs much 1 educed in size and even rudimentary, or their fingers partially coherent, so that their hands are con- verted into mere grasping-hooks.63
As soon as some ancient member in the great series of the Primates came, owing to a change in its manner of procuring subsistence, or to a change in the con-
02 ‘ Quarterly "Review,’ April, 1869, p. 392.
1,3 In llylobates syndactylus, as the name expresses, two of the digits regularly cohere ; and this, as Mr. Blytli informs me, is occasionally the case with the digits of H. agilis, lar, and leucisous. In Colobus the thumb is likewise deficient; these monkeys are strictly arboreal and extraordinarily active (Brehm, ‘ Tliierleben,’ B. i. s. 50), but whether they are better climbers or graspers than the species of the allied genera, I do not know.
Chap. iv.
MANNER OE DEVELOPMENT.
141
ditions of its native country, to live somewhat less on trees and more on the ground, its manner of progres- sion would have been modified ; and in this case it would have had to become either more strictly quad- rupedal or bipedal. Baboons frequent hilly and rocky districts, and only from necessity climb up high trees ; 64 and they have acquired almost the gait of a dog. Man alone has become a biped ; and we can, I think, paitly see how he has come to assume his erect attitude, which forms one of the most conspicuous differences between him and his nearest allies. Man could not have attained his present dominant position in the world Without the use of his hands which are so admirably adapted to act in obedience to his will. As Sir C. Bell insists “the hand supplies all instruments, and by its “ correspondence with the intellect gives him universal “dominion.” But the hands and arms could hardly have become perfect enough to have manufactured Weapons, or to have hurled stones and spears with a true aim, as long as they were habitually used for locomotion and for supporting the whole weight of the body, or as long as they were especially well adapted, as previously remarked, for climbing trees. Such rough treatment would also have blunted the sense of touch, which their delicate use largely depends. From these causes alone it would have been an advantage to rmtu to have become a biped ; but for many actions it is almost necessary that both arms and the whole upper Part of the body should be free; and he must for this ^d stand firmly on his feet. To gam this great advantage, the feet have been rendered flat, and the great toe peculiarly modified, though this has entailed the loss of the power of prehension. It accords with
61 Brehm, ‘ Thierleben,’ B. i. s. SO.
65 “ The Hand,” &c. 1 Bridgewater Treatise,’ 1S33, p. 3S.
142
THE DESCENT OF MAN.
Part 1-
the principle of the division of physiological labour, which prevails throughout the animal kingdom, that as the hands became perfected for prehension, the feet should have become perfected for support and locomotion. With some savages, however, the foot has not altogether lost its prehensile power, as shewn by their manner of climbing trees and of using them iu other ways.66
If it be an advantage to man to have his hands and arms free and to stand firmly on his feet, of which there can be no doubt from his pre-eminent success in the battle of life, then I can see no reason why it should not have been advantageous to the progenitors of man to have become more and more erect or bipedal. They would thus have been better able to have defended themselves with stones or clubs, or to have attacked their prey, or otherwise obtained food. The best con- structed individuals would in the long run have succeeded best, and have survived in larger numbers. If the gorilla and a few allied forms had become extinct, it might have been argued with great force and apparent truth, that an animal could not have been gradually converted from a quadruped into a biped; as all the individuals in an intermediate condition would have been miserably ill-fitted for progression. But we know (and this is well worthy of reflection) that several kinds of apes are now actually in this intermediate condition; and no one doubts that they are on the whole well adapted for their conditions of life. Thus the gorilla
“ Ilaelcel tins an excellent discussion on the steps by which nian became a biped : ‘ Natiirliche Schopfungsgeschichtc,’ 18(58, s. 507. Dr- Buchner Conferences sur la Theoriu Darwinienne,’ 1809, p. 135) has given good cases of the use of the foot as a prehensile organ by man : also on the manner of progression of the higher apes to which I allude in tlio following paragraph : see also Owen (‘ Anatomy of Vertebrates, vol. iii. p. 71) on this latter subject.
Chap. IV.
MANNER OF DEVELOPMENT.
143
runs with a sidelong shambling gait, but more commonly progresses by resting on its bent hands. The long- armed apes occasionally use their arms like crutches, swinging their bodies forward between them, and some kinds of Hylobates, without having been taught, can Walk or run upright with tolerable quickness ; yet they move awkwardly, and much less securely than man. We see, in short, with existing monkeys various grada- tions between a form of progression strictly like that of a quadruped and that of a biped or man.
As the progenitors ol man became more and more erect, with their hands and arms more and more modi- fied for prehension and other purposes, with their feet and legs at the same time modified for firm support and progression, endless other changes of structure would have been necessary. The pelvis would have had to be made broader, the spine peculiarly curved and the head fixed in an altered position, and all these changes have been attained by man. Prof. Schaafi- hausen67 maintains that “ the powerful mastoid processes of the human skull are the result of his erect position and these processes are absent in the orang, chim- panzee, &e., and are smaller in the gorilla than in man. Various other structures might here have been specified, which appear connected with man’s erect position. It is very difficult to decide how far all these correlated Wrodifications are the result of natural selection, and how far of the inherited effects ol the increased use oi certain parts, or of the action of oue part on another. Vo doubt these means of change act and react on each °ther : thus when certain muscles, and the crests of h°ue to which they are attached, become enlarged by
07 “ On the Primitive Form of the Skull,” translated in 1 Anthropo- logical Review,’ Oct. 1868, p. 428. Owen (: Anatomy of Vertebrates,’ v°b ii. 1SU6, p. 551) on the mastoid processes in the higher apes.
144
THE DESCENT OF MAN.
Part I.
habitual use, this shews that certain actions are habitually performed and must be serviceable. Hence the individuals which performed them best, would tend to survive in greater numbers.
The free use of the anus and hands, partly the cause and partly the result of man’s erect position, appears to have led in an indirect manner to other modifications of structure. The early male progenitors of man were, as previously stated, probably furnished with great canine teeth : but as they gradually acquired the habit of using stones, clubs, or other weapons, for fighting with their enemies, they would have used their jaws and teeth less and less. In this case, the jaws, together with the teeth, would have become reduced in size, as we may feel sure from innumerable analogous cases. In a future chapter we shall meet with a closely-parallel case, in the reduction or complete disappearance of the canine teeth in male ruminants, apparently in relation with the development of their horns ; and in horses, in relation with their habit of fighting with their incisor teeth and hoofs.
In the adult male anthropomorphous apes, as Kuti- meyer,68 and others have insisted, it is precisely the effect which the jaw-muscles by their great development have produced on the skull, that causes it to differ so greatly in many respects from that of man, and has given to it “ a truly frightful physiognomy.” Therefore as the jaws and teeth in the progenitors of man gradually become reduced in size, the adult skull would have presented nearly the same characters which it offers in the young of the anthropomorphous apes, and would thus have come to resemble more nearly that of existing
68 ‘Die Grenzen der Thierwelt, eine Betraelitung zu Darwin’s Lehre,’ 1868, s. 51.
Chap. IV.
MANNER OP DEVELOPMENT.
145
man. A great reduction of tlie canine teeth in the males would almost certainly, as we shall hereafter see, have affected through inheritance the teeth of the females.
As the various mental faculties were gradually de- veloped, the brain would almost certainly have become larger. No one, I presume, doubts that the large size of the brain in man, relatively to his body, in compari- son with that of the gorilla or orang, is closely con- nected with his higher mental powers. A\ e meet with closely analogous facts with insects, in which the cerebral ganglia are of extraordinary dimensions in ants; these ganglia in all the Hymenoptera being many times larger than in the less intelligent orders, such as beetles. On the other hand, no one supposes that the intellect of any two animals or of any two men can be accurately gauged bv the cubic contents of their skulls. It is certain that there may be extraordinary mental activity with an extremely small absolute mass of nervous matter : thus the wonderfully diversified instincts,
mental powers, and affections of ants are generally known, yet their cerebral ganglia are not so large as the Quarter of a small pin’s head. Under this latter point of view, the brain of an ant is one of the most marvellous atoms of matter in the world, perhaps more marvellous than the brain of man.
The belief that there exists in man some close relation between the size of the brain and the development of the intellectual faculties is supported by the comparison °f the skulls of savage and civilised races, of ancient and Modern people, and by the analogy of the whole verte-
60 Dujardm, ‘Annales des Sc. Nat.’ 3rd series, Zoolog. tom. xiv. 1S50, p. 203. See also Mr. Lowne, 1 Anatomy and Phys. of the Musca vomitorla,’ 1870, p. 14. My son, Mr. F. Darwin, dissected for me the cerebral ganglia of the Formica rufa.
■VOL. I.
L
146
THE DESCENT OF MAN.
P-AET I.
brate series. Dr. J. Barnard Davis has proved70 bv many careful measurements, that the mean internal capacity of the skull in Europeans is 92‘3 cubic inches; in Americans 87‘5 ; in Asiatics 87T ; and in Australians only 8D9 inches. Professor Broca71 found that skulls from graves in Paris of the nineteenth century, were larger than those from vaults of the twelfth century, in the proportion of 1 484 to 1426 ; and Prichard is per- suaded that the present inhabitants of Britain have “much more capacious brain-cases” than the ancient inhabitants. Nevertheless it must be admitted that some skulls of very high antiquity, such as the famous one of Neanderthal, are well developed and capacious. With respect to the lower animals, M. E. Lartet,72 by com- paring the crania of tertiary and recent mammals, be- longing to the same groups, has come to the remarkable conclusion that the brain is generally larger and the convolutions more complex in the more recent form- On the other hand I have shewn 73 that the brains of domestic rabbits are considerably reduced in bulk, in comparison with those of the wild rabbit or hare ; and this may be attributed to their having been closely con- fined during many generations, so that they have exerted but little their intellect, instincts, senses, and voluntary movements.
The gradually increasing weight of the brain and skull in man must have influenced the development of the supporting spinal column, more especiallv whilst he was becoming erect. As this change of position was
70 ‘Philosophical Transactions,’ 1809, p. 513.
71 Quoted in C. Vogt’s ‘Lectures on Man,’ Eng. translat. 1 864, p- 88, 90. Prichard, ‘Phys. Hist, of Mankind, ’ vol. i. 1838, p. 305.
72 ‘ Comptes Eendus des Seances,’ &c. June 1, 1868.
73 ‘ The Variation of Animals and Tlants under Domestication,’ vol- i. p. 124-129.
Chap. IV.
MANNER OP DEVELOPMENT.
147
being brought about, the internal pressure of the brain, will, also, have influenced the form of the skull ; for many facts shew how easily the skull is thus affected. Ethnologists believe that it is modified by the kind of cradle in which infants sleep. Habitual spasms of the muscles and a cicatrix from a severe burn have per- manently modified the facial bones. In young persons whose heads from disease have become fixed either sideways or backwards, one of the eyes has changed its position, and the bones of the skull have been modified ; and this apparently results from the brain pressing in a new direction.74 I have shewn that with long-eared rabbits, even so trifling a cause as the lopping forward of one ear drags forward on that side almost every bone of the skull ; so that the bones on the oppo- site sides no longer strictly correspond. Lastly, if any animal were to increase or diminish much in general size, without any change in its mental powers ; or it the mental powers were to be much increased or diminished without any great change in the size ot the body ; the shape of the skull would almost certainly be altered. I infer this from my observations on domestic mbbits, some kinds of which have become very much larger than the wild animal, whilst others have retained nearly the same size, but in both cases the brain has been much reduced relatively to the size oi the body. How I was at first much surprised by finding that in all these rabbits the skull had become elongated or doliclio-
74 Schanft'hausen gives from Blumenbuch and Busch, the cases of the sPasms und cicatrix, in ‘ Anthropolog. Be view, 7 Oct. 1808, p. 420. Dr. Jarrold Antkropologia,’ 1808, p. 115, 116) adduces from Camper and from Lis own observations, cases of the modification ot the skull from the Lead being fixed in an unnatural position. He believes that cer- tain trades, such, as that of a shoemaker, by causing the head to be habitually held forward, makes the forehead more rounded and prominent.
148
THE DESCENT OP MAN.
Part I.
cephalic; for instance, of two skulls of nearly equal breadth, the one from a wild rabbit and the other from a large domestic kind, the former was only 3'15 and the latter 4-3 inches in length.75 One of the most marked distinctions in different races of man is that the skull in some is elongated, and in others rounded ; and here the explanation suggested by the case of the rabbits may partially hold good ; for Welcker finds that short “men incline more to brachycephaly, and tall men to doliehocephaly ; ” ,b and tall men maybe compared with the larger and longer-bodied rabbits, all of which have elongated skulls, or are dolichocephalic.
From these several facts we can to a certain ex- tent understand the means through which the great size and more or less rounded form of the skull has been acquired by man ; and these are characters emi- nently distinctive of him in comparison with the lower animals.
Another most conspicuous difference between man and the lower animals is the nakedness of his skin. Whales and dolphins (Cetacea), dugongs (Sirenia) and the hip- popotamus are naked ; and this may be advantageous to them for gliding through the water; nor would it be injurious to them from the loss of warmth, as the species which inhabit the colder regions are protected by a thick layer of blubber, serving the same purpose as the fur of seals and otters. Elephants and rhino* ceroses are almost hairless ; and as certain extinct species which formerly lived under an arctic climate were covered with long wool or hair, it would almost appear as if the existing species of both genera had lost
‘Variation of Animals,’ &c., vol. i. p. 117 on the elongation of tl10 skull ; p. 119, on the effect of the lopping of one ear.
'6 Quoted by Schaafiliuuscn, in ‘ Anthronolog. Beviow,’ Oct. 1868, p. 410.
C«AP. IV.
MANNER OP DEVELOPMENT.
149
their hairy covering from exposure to heat. This appears the more probable, as the elephants in India which live on elevated and cool districts are more hairy" than those on the lowlands. May we then infer that man became divested of hair from having aboriginally inhabited some tropical land? The fact of the hair being chiefly retained in the male sex on the chest and face, and in both sexes at the junction of all four limbs with the trunk, favours this inference, assuming that the hair was lost before man became erect ; lor the parts which now retain most hair would then have been most protected from the heat of the sun. The crown of the head, however, offers a curious exception, for at all times it must have been one of the most exposed parts, yet If is thickly clothed with hair. In this respect man agrees with the great majority of quadrupeds, which generally have their upper and exposed surfaces more thickly clothed than the lower surface. Nevertheless, the fact that the other members of the order of Pri- mates, to which man belongs, although inhabiting vari- es hot regions, are well clothed with hair, generally thickest on the upper surface,'8 is strongly opposed to the supposition that man became naked through the Action of the sun. I am inclined to believe, as we shall see under sexual selection, that man, or rathei Primarily woman, became divested of hair for orna- mental purposes ; and according to this belief it is not
‘l Owen, ‘ Anatomy of Vertebrates,’ vol. iii. p. 619- .. ’* Isidore Geoffroy St-HLlaire remarks (‘Hist. Nat. Generate, tom. 11 • 1859, p. 215-217 j on the head of man being covered with long hair ; ako on the upper surfaces of monkeys and of other mammals being *Oore thickly clothed than the lower surfaces. This has likewise been observed by various authors. Prof. I’. Gervais ■/ Hist. Nat. des Mam- ohferes,’ tom. i. 1S54, p. 2S), however, states that in the Gorilla the i air is thinner on the back, whore it is partly rubbed off, than on the l°Wer surface.
150 THE DESCENT OF MAN. PAST I-
surprising that man should differ so greatly in hairi- ness from all his lower brethren, for characters gained through sexual selection often differ in closely-related forms to an extraordinary degree.
According to a popular impression, the absence of a tail is eminently distinctive of man ; but as those apes which come nearest to man are destitute of this organ, its disappearance does not especially concern us. Never- theless it may be well to own that no explanation, as tar as I am aware, has ever been given of the loss of the tail by certain apes and man. Its loss, however, is not surprising, for it sometimes differs remarkably in length in species of the same genera: thus in some species of Macacus the tail is longer than the whole body, con- sisting of twenty-four vertebras ; in others it consists of a scarcely visible stump, containing only three or four vertebrae. In some kinds of baboons there are twenty- five, whilst in the mandrill there are ten very small stunted caudal vertebras, or, according to Cuvier,79 some- times only five. This great diversity in the structure and length of the tail in animals belonging to the same genera, and following nearly the same habits of life, renders it probable that the tail is not of much importance to them ; and if so, we might have expected that it would sometimes have become more or less rudimentary, 111 accordance with what we incessantly see with other struc- tures. 'The tail almost always tapers towards the end whether it be long or short ; and this, I presume, re- sults from the atrophy, through disuse, of the terminal muscles together with their arteries and nerves, lead- ing to the atrophy of the terminal bones. With respect
79 Mr. St. George Mivart, ‘Proc. Zoolog. Soc.’ 1SG5, p. 562, 583- Dr. J. E. Gray, ‘Cat. Brit. Mus. : Skeletons.’ Owen, ‘Anatomy 0 Yertebrates,’ vol. ii. p. 517. Isidore Geoffroy, ‘Hist. Nat. Ge'n.’ tom. li p. 244.
Chap. IV.
MANNER OF DEVELOPMENT.
151
to the os coccyx, which in man and the higher apes manifestly consists of the few basal and tapering seg- ments of an ordinary tail, I have heard it asked liow could these have become completely embedded within the body ; but there is no difficulty in this respect, for in many monkeys the basal segments of the true tail are thus embedded. 1 or instance, Mr. Murie in- forms me that in the skeleton of a not full-grown Naiacus inormtus , he counted nine or ten caudal ver- tebra, which altogether were only 1’8 inch in length. Of these the three basal ones appeared to have been embedded ; the remainder forming the free part of the tail, which was only one inch in length, and half an inch in diameter. Here, then, the three embedded caudal vertebrae plainly correspond with the four coal- esced vertebrae of the human os coccyx.
I have now endeavoured to shew that some of the most distinctive characters ol man have in all proba- bility been acquired, either directly, or more commonly indirectly, through natural selection. We should bear in mind that modifications in structure or constitution, which are of no service to an organism in adapt- ing it to its habits of life, to the food which it con- sumes, or passively to the surrounding conditions, can- not have been thus acquired. W e must not, however, be too confident in deciding what modifications are of service to each being : we should remember how little We know about the use of many parts, or what changes in the blood or tissues may serve to fit an organism for a new climate or some new kind ot food. Nor must we forget the principle of correlation, by which, as Isidore Geoffroy has shewn in the case of man, many- strange deviations of structure are tied together. Inde- pendently of correlation, a change in one part often leads
152
THE DESCENT OF MAN.
Part I.
through the increased or decreased use of other parts, to other changes of a quite unexpected nature. It is also well to reflect on such facts, as the wonderful growth of galls on plants caused by the poison of an insect, and on the remarkable changes of colour in the plumage of parrots when fed on certain fishes, or in- oculated with the poison of toads;80 for we can thus see that the fluids of the system, if altered for some special purpose, might induce other strange changes. We should especially bear in mind that modifications acquired and continually used during past ages for some useful purpose would probably become firmly fixed and might be long inherited.
Thus a very large yet undefined extension may safely be given to the direct and indirect results of natural selection ; but I now admit, after reading the essay by Nagel i on plants, and the remarks by various authors with respect to animals, more especially those recently made by Professor Broca, that in the earlier editions of my £ Origin of Species’ I probably attributed too much to the action of natural selection or the survival of the fittest. I have altered the fifth edition of the Origin so as to confine my remarks to adaptive changes of structure. I had not formerly sufficiently considered the existence of many structures which appear to be, as far as wo can judge, neither beneficial nor injurious ; and this I believe to be one of the greatest oversights as yet detected in my work. I may be permitted to say as some excuse, that I had two distinct objects in view, firstly, to shew that species had not been separately created, and secondly, that natural selection had been the chief agent of change, though largely aided by the
80 ‘ The Variation of Animals and Plants under Domestication,’ vol. ii. p. 280, 282,
Chap. iv.
MANNER OF DEVELOPMENT.
153
inherited effects of habit, and slightly by the direct action of the surrounding conditions. Nevertheless I was not able to annul the influence of my former belief, then widely prevalent, that each species had been purposely created; and this led to my tacitly assuming that every detail of structure, excepting iudi- meats, was of some special, though unrecognised, ser- vice. Any one with this assumption in his mind would naturally extend the action of natural selection, either during past or present times, too far. borne o t ose who admit the principle of evolution, but reject natural selection, seem to forget, when criticising my book that I had the above two objects in view; hence if i have erred in giving to natural selection great power, which I am far from admitting, or in having exaggerated its power, which is in itself probable, I have at least, as 1 hope, done good service in aiding to overthrow the
dogma of separate creations.
That all organic beings, including man, present many modifications of structure which are of no service to them at present, nor have been formerly, is, as I can how see, probable. We know not wbat produces the numberless slight differences between the individuals oi each species, for reversion only carries the problem a few steps backwards ; but each peculiarity must have had its own efficient cause. If these causes, whatever they may he, were to act more uniformly and energetically during a lengthened period (and no reason can be assigned why this should not sometimes occur), the result would probably be uot mere slight individual differences, but well-marked, constant mollifications. Modifications which are in no way beneficial cannot have been kept uniform through natural selection, though any which were injurious would have been thus eliminated. Uniformity of character would, however,
154
THE DESCENT OF MAN.
Pact I.
naturally follow from the assumed uniformity of the exciting causes, and likewise from the free intercros- sing ol many individuals. The same organism might acquire in this manner during successive periods suc- cessive modifications, and these would he transmitted in a nearly uniform state as long as the exciting causes remained the same and there was free intercrossing. With respect to the exciting causes we can only say, as when speaking of so-called spontaneous variations, that they relate much more closely to the constitution of the varying organism, than to the nature of the conditions to which it has been subjected.
Conclusion.— In this chapter we have seen that as man at the present day is liable, like every other animal, to multiform individual differences or slight variations, so no doubt were the early progenitors of man ; the varia- tions being then as now induced by the same general causes, and governed by the same general and complex laws. As all animals tend to multiply beyond their means ot subsistence, so it must have been with the progenitors of man ; and this will inevitably have led to a struggle for existence and to natural selection. This latter process will have been greatly aided by the inherited effects of the increased use of parts; these two processes incessantly reacting on each other. It appears, also, as we shall herealter see, that various unimportant characters have been acquired by man through sexual selection. An unexplained residuum of change, perhaps a large one, must be left to the assumed uniform action of those unknown agencies, which occasionally induce strongly-marked and abrupt deviations of structure in our domestic productions.
J udging from the habits of savages and of the greater number of the Quadrumana, primeval men, and even
Chap. IV.
MANNER OF DEVELOPMENT.
155
the ape-like progenitors of man, probably lived in society. With strictly social animals, natural selection sometimes acts indirectly on the individual, through the preservation of variations which are beneficial only to the community. A community including a large number of well-endowed individuals increases m number and is victorious over other and less well-endowed com- munities; although each separate member may gain no advantage over the other members of the same com- munity. With associated insects many remarkable structures, which are of little or no service to the indi- vidual or its own offspring, such as the pollen-collectmg apparatus, or the sting of the worker-bee, or the great jaws of soldier-ants, have been thus acquire . With the higher social animals, I am not aware that any structure has been modified solely for the good ot the community, though some are of secondary service to it. For instance, the horns of ruminants and the great canine teeth of baboons appear to have been acquired by the males as weapons lor sexual strife, but they are used in defence of the herd or troop. In regard to certain mental faculties the case, as we shall see in the following chapter, is wholly different; lor these faculties have been chiefly, or even exclusively, gained for the benefit of tbe community ; the indi- viduals composing the community being at e same time indirectly benefited.
It has often been objected to such views as the fore- going, that man is one of the most helpless am de ence- less creatures in the world ; and that during his ear y and less well-developed condition he would have been still more helpless. The Duke of Argyll, for instance, insists81 that “ the human frame has diverged from
81 ‘ Primeval Man/ 1S69, p. t>6.
156
THE DESCENT OF MAN.
Part I.
“ the structure of brutes, in the direction of greater “ physical helplessness and weakness. That is to say, “ it is a divergence which of all others it is most “ impossible to ascribe to mere natural selection.” He adduces the naked and unprotected state of the body, the absence of great teeth or claws for defence, the little strength of man, his small speed in running, and his slight power of smell, by which to discover food or to avoid danger. To these deficiencies there might have been added the still more serious loss of the power of quickly climbing trees, so as to escape from enemies. Seeing that the unclothed Fuegians can exist under their wretched climate, the loss of hair would not have been a great injury to primeval man, if he inha- bited a warm country. When we compare defenceless man with the apes, many of which are provided with formidable canine teeth, we must remember that these in their fully-developed condition are possessed by the males alone, being chiefly used by them for fighting with their rivals; yet the females which are not thus provided, are able to survive.
In regard to bodily size or strength, we do not know whether man is descended from some comparatively small species, like the chimpanzee, or from one as powerful as the gorilla ; and, therefore, we cannot say whether man ba3 become larger and stronger, or smaller and weaker, in comparison with his progenitors. We should, however, bear in mind that an animal possessing great size, strength, and ferocity, and which, like the gorilla, could defend itself from all enemies, would probably, though not necessarily, have tailed to become social ; and this would most effectually have checked the acquirement by man of his higher mental quali- ties, such as sympathy and the love of his fellow- creatures. Hence it might have been an immense
Chap. IV.
MANNER OE DEVELOPMENT.
157
advantage to man to have sprang from some com- paratively weak creature.
The slight corporeal strength of man, his little speed, his want ot natural weapons, &c., are more than coun- terbalanced, firstly by his intellectual powers, through which ho has, whilst still remaining in a barbarous state, formed for himself weapons, tools, &c., and secondly by his social qualities which lead him to give aid to his fellow-men and to receive it in return. No country in the world abounds in a greater degree with dan- gerous beasts than Southern Africa; no country pre- sents more fearful physical hardships than the Arctic regions ; vet one of the puniest races, namely, the Bushmen, maintain themselves in Southern Airica, as do the dwarfed Esquimaux in the Arctic regions. Ihe early progenitors 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, whilst they gradually lost their brute-like powers, such as climbing trees, &c., they at the same time advanced in inteliect. But granting that the progenitors of man were far more helpless and defenceless than any existing savages, if they had inhabited some warm continent or large island, such as Australia or New Guinea, or Borneo (the latter island being now tenanted by t e orang), they would not have been exposed to any special danger. In an area as large as one of these islands, the competition between tribe and tribe would have been, sufficient, under favourable conditions, to have raised mail, through the survival ot the fittest, combined with the inherited effects of habit, to his present high position in the organic scale.
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CHAPTER Y.
On the Development or the Intellectual and Moral Faculties during Primeval and Civilised Times.
The advancement of the intellectual powers through natural selec- tion— Importance of imitation — Social and moral faculties — Their development within the limits of the same tribe— Natural selection as affecting civilised nations — Evidence that civilised nations were once barbarous.
The subjects to be discussed in this chapter are of the liigliest interest, but are treated by me in a most imperfect and fragmentary manner. Mr. Wallace, in an admirable paper before referred to,1 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 have had his bodily structure modified through natural selection or any other means. For man is enabled through his mental faculties “to keep with an un- “ changed 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, by which he procures food and defends 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 anticipates future events. Even at a remote period he practised some subdivision of labour.
‘ Anthropological Beview,’ May, 1S64, p. clviii.
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The lower animals, on the other hand, must have their bodily structure modified in order to survive under greatly changed conditions. They must be rendered stronger, or acquire more effective teeth or claws, in order to defend themselves from 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 ease, however, is widely different, as Mr. Wal- lace has with justice insisted, in relation to the intel- lectual and moral faculties of man. These faculties are ' triable ; and we have every reason to believe that the ''ariations tend to bo inherited. Therefore, if they were formerly of high importance to primeval man and to l‘is ape-like progenitors, they would have been per- fected or advanced through natural selection. Of the high importance of the intellectual faculties there can he no doubt, for man mainly owes to them his pre- eminent position in the world. Wc can see that, in the rudest state of society, the individuals who were the most sagacious, who invented and used the best weapons 0r traps, and who were best able to defend themselves, "ronld rear the greatest number of offspring. The tribes "'hich included the largest number of men thus endowed "ould increase in number and supplant other tribes. ^Umbers depend primarily on the means of subsistence, aud this, partly on the physical nature of the country, Imt in a much higher degree ou the arts which are there practised. As a tribe increases and is victorious, it is °ften still further increased by the absorption of other tribes.2 The stature and strength of the men of a tribe
After a time the members or tribes which are absorbed into another |Lbe assume, as Mr. Maine remarks (‘Ancient Law,’ 1861, p. 131), that
ley we the co-descendants of the same ancestors.
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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 more powerful and, judging from their sword- handles, larger-handed race;3 but their success was probably due in a much higher degree to their superiority in the arts.
All that we know about savages, or may infer from their traditions and from old monuments, the history of which is quite forgotten by the present inhabitants, shew that from the remotest times successful tribes have supplanted other tribes. Eelies of extinct or forgotten tribes have been discovered throughout the civilised regions of the earth, on the wild plains of America, and on the isolated islands in the Pacific Ocean. At the present day civilised nations are everywhere supplanting barbarous nations, excepting where the climate opposes a deadly barrier ; and they succeed mainly, though not exclusively, through their arts, which are the products of the intellect. It is, therefore, highly probable that with mankind the intellectual faculties have been gradually perfected through natural selection ; and this conclusion is sufficient for our purpose. Undoubtedly it would have been very interesting to have traced the development of each separate faculty from the state in which it exists in the lower animals to that in which d exists in man ; but neither my ability nor knowledge permit the attempt.
It deserves notice that as soon as the progenitors of man became social (and this probably occurred at il very early period), the advancement of the intellectual faculties will have been aided and modified in an important manner, of which we see only traces
1 Morlot, 1 Soc. Vaud. Sc. Nat.’ I860, p. 294.
Chap. V. INTELLECTUAL FACULTIES. 161
the lower animals, namely, through the principle of imitation, together with reason and experience. Apes are much given to imitation, as are the lowest savages ; and the simple fact previously referred to, that after a time no animal can be caught in the same place by the same sort of trap, shews that animals learn hy experience, and imitate each others’ caution. Now, if some one man in a tribe, more sagacious than the others, invented a new snare or weapon, or other means °f attack or defence, the plainest self-interest, without the assistance of much reasoning power, would prompt the other members to imitate him ; and all would thus profit. The habitual practice of each new art must likewise in some slight degree strengthen the intellect. If the new invention were an important one, the tribe Would increase in number, spread, and supplant other tribes. In a tribe thus rendered more numerous there Would always be a rather better chance of the birth of other superior and inventive members. If such men left children to inherit their mental superiority, the chance of the birth of still more ingenious members Would be somewhat better, and in a very small tribe decidedly better. Even if they left no children, the tribe would still include their blood-relations ; and it has doeu ascertained by agriculturists4 that by preserving aod 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 °f man, should have become social, they must have
4 I have given instances in my ‘ Variation of Animals under Domes- “cation,’ vol. ii. p. 196.
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acquired tlie same instinctive feelings which impel other animals to live in a body; and they no doubt exhi- bited 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 o the lower animals is disputed by no one, were no doubt acquired by the progenitors of man in a similar manner, namely, through natural selection, aided by inherited habit. When two tribes of primeval man, living in the same country, came into competition, if the one tribe included (other circumstances being' equal) a greater number of courageous, sympathetic, and faithful members, who were always ready to warn each other of danger, to aid and defend each other, this tribe would without doubt succeed best and conquer the other. Let it be borne in mind how all-important, i» the never-ceasing wars of savages, fidelity and courage must be. The advantage which disciplined soldiers have over undisciplined hordes follows chiefly from the confidence which each man feels in his comrades. Obedience, as Mr. Bagehot has well shewn,5 is of the highest value, for any form of government is better than none. Selfish and contentious people will not cohere, and without coherence nothing can be effected. A tribe possessing the above qualities in a high de- gree would spread and be victorious over other tribes ; hut in the course of time it would, judging from all past history, be in its turn overcome by some other
5 See a remarkable series of articles on Physics and Politics in the 1 Fortnightly Review,’ Nov. 1867; April 1, 1868; July 1, 1869.
Chap. V.
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and still more highly endowed tribe. Thus the social and moral qualities would tend slowly to advance and he diffused throughout the world.
But it may be asked, how within the limits oi the same tribe did a large number of members first become endowed with these social and moral qualities, and how was the standard of excellence raised ? It is extremely doubtful whether the offspring of the more sympathetic and benevolent parents, or ot those which "ere the most faithful to their comrades, would be reared in greater number than the children of selfish and treacherous parents of the same tribe. He who Was ready to sacrifice his life, as many a savage has been, rather than betray his comrades, would often leave no offspring to inherit his noble nature. Ihe bravest uien, 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 number than other men. I' herefore it seems scarcely possible (bearing in mind that we are not here speaking of one tribe being vic- torious over another) that the number of men gifted With such virtues, or that the standard of their excel- lence, could be increased through natural selection, that is, by the survival of the fittest.
Although the circumstances which lead to an increase in the number of men 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 from experience that if he aided his fellow-men, he would commonly receive aid in return. From this low motive he might acquire the habit ot aiding his fellows ; and the habit of performing benevolent actions certainly strengthens the feeling of sympathy, which gives the
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first impulse to benevolent actions. Habits, moreover, followed during many generations probably tend to be inherited.
But there is another and much more powerful sti- mulus to the development of the social virtues, namely, the praise and the blame of our fellow-men. The love of approbation and the dread of infamy, as well as the bestowal of praise or blame, are primarily due, as we have seen in the third chapter, to the instinct of sym- pathy; and this instinct no doubt was originally acquired, like all the other social instincts, through natural selec- tion. At how early a period the progenitors of man, in the course of their development, became capable of feel- ing 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 decorations ; for unless they regarded the opinion of their comrades, such habits would be senseless.
They certainly feel shame at the breach of some of their lesser rules ; but how far they experience remorse is doubtful. I was at first surprised that I could not re- collect any recorded instances of this feeling in savages ; and Sir J. Lubbock6 states that he knows of none. But if we banish from our minds all cases given in novels and plays and in death-bed confessions made to priests, I doubt whether many of us have actually witnessed remorse; though we may have often seen shame and contrition for smaller offences. Remorse is
6 • Origin of Civilisation,’ 1870, p. 265.
Chap. V.
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a deeply hidden feeling. It is incredible that a savage, who will sacrifice his life rather than betray his tribe, or one who will deliver himself up as a prisoner rather than break his parole,7 would not feel remorse in his inmost soul, though he might conceal it, if ho had failed in a duty which he held sacred.
We may therefore conclude that primeval man, at a very remote period, would have been influenced by the praise and blame of his fellows. It is obvious, that the members of the same tribe would approve ol conduct which appeared to them to be for the general good, and "'ould reprobate that which appeared evil. To do good nnto 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 impor- tance 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 °f others, yet was roused to such actions by a sense °f glory, would by his example excite the same wish for glory in other men, and would strengthen by exer- cise 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, &c., "’hi ch during early times are, as we have before seen, utterly disregarded, come to be highly esteemed or even held sacred. I need not, however, repeat what I have said on this head in the third chapter. Ultimately a highly complex sentiment, having its first origin in the
7 Mr. Wallace gives cases in liis £ Contributions to tlie Theory of ■Natural Selection/ 1870, p. 354.
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social instincts, largely guided by the approbation ot our fellow-men, ruled by reason, self-interest, and in later times by deep religious feelings, confirmed by instruction and habit, all combined, constitute our moral sense or conscience.
It must not be forgotten that although a high stand- ard 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 advancement in the standard of morality and an increase in the number of well-endowed men will certainly give an immense advantage to one tribe over another. There can be no doubt that a tribe including many members who, from possessing in a high degree the spirit of patriotism, fidelity, obedience, courage, and sympathy, were always ready to give aid to each other and to sacrifice them- selves for the common good, would he victorious over most other tribes ; and this would be natural selection. At all times throughout tho world tribes have sup- planted other tribes ; and as morality is one element in their success, the standard of morality and the num- ber 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 civilisation. Many savages are in the same condition as when first discovered several centuries ago. As Mr. Bagehot has remarked, we are apt to look at progress as the normal rule in human society ; but history refutes this. The ancients did not even entertain the idea ; nor do the oriental nations at the present day. According to another high authority, Air. Maine,8 “the greatest part of mankind has never
8 ‘Ancient Law,’ 1S61, p. 22. For Mr. Bugeliot’s remarks, ‘Fort- nightly Review,’ April 1, 1S68, p. 452.
Chap. V.
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“ shewn a particle of desire that its civil institutions “ should be improved.” Progress seems to depend ou many concurrent favourable conditions, far too complex to he followed out. But it has often been remarked, that a cool climate from leading to industry and the various arts has been highly favourable, or even indispensable for this end. The Esquimaux, pressed by hard necessity , have succeeded in many ingenious inventions, but their climate has been too severe for continued progress. Nomadic habits, whether over wide plains, or through the dense forests of the tropics, or along the shores of the sea, have in every case been highly detrimental. Whilst observing the barbarous inhabitants of lierra del Fuego, it struck me that the possession of some property, a fixed abode, and the union of many families under a chief, were the indispensable requisites for civilisation. Such habits almost necessitate the culti- vation of the ground ; and the first steps in cultivation Would probably result, as 1 have elsewhere shewn,9 from some such accident as the seeds ot a fruit-tree falling on a heap of refuse and producing an unusually fine Variety. The problem, however, of the first advance of savages towards civilisation is at present much too diffi- cult to be solved.
Natural Selection as affecting Civilised Nations. In the last and present chapters I have considered the advancement of man from a former semi-human con- dition to his present state as a barbarian. But some remarks on the agency of natural selection on civilised nations mav be here worth adding. 1 his subject has been ably discussed by Mr. W. R. Greg,10 and previously
9 1 Tlie Variation of Animals and Plants under Domestication,’ vol. i. P. 309.
10 1 Fraser’s Magazine,’ Sept. 186S, p. 353. This article seems to have struck many persons, and has given rise to two remarkable essays
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by Mr. Wallace and Mr. Galton.11 Most of my remarks are taken from these three authors. With savages, the weak in body or mind are soon eliminated ; and those that survive commonly exhibit a vigorous state of health. We civilised men, on the other hand, do our utmost to check the process of elimination; we build asylums for the imbecile, the maimed, and the sick ; we institute poor-laws; and our medical men exert their utmost skill to save the life of every one to the last moment. There is reason to believe that vaccination has preserved thousands, who from a weak constitution would formerly have succumbed to small-pox. Thus the weak members of civilised societies propagate their kind. No one who has attended to the breeding of domestic animals will doubt that this must be highly injurious to the race of man. It is surprising how soon a, want of care, or care wrongly directed, leads to the degeneration of a domestic race ; but excepting in the case ol man himself, hardly any one is so ignorant as to allow his worst animals to breed.
The aid which we feel impelled to give to the help- less is mainly an incidental result of the instinct of sympathy, which was originally acquired as part of the social instincts, but subsequently rendered, in the manner previously indicated, more tender and more widely diffused. Ivor could we check our sympathy, ii so urged by hard reason, without deterioration in the
and a rejoinder in the * Spectator,1 Oct. 3rd and 17th 1868. It has also been discussed in the ‘ Q. Journal of Science,’ I860, p. 152, and by Mr. Lawson Tait in the ‘Dublin Q. Journal of Medical Science,’ Feb. 1869, and by Mr. K. Kay Lankester in his ‘ Comparative Longevity,’ 1S70, p. 128. Similar views appeared previously in the ‘Australasian,’ July Id, 1867. I have borrowed ideas from several of these writers.
For Mr. Wallace, see ‘ Anthropolog. Keview,’ as before cited. Mr. Galton in ‘Macmillan’s Magazine,’ Aug. 1865, p. 318; also his great work, ‘ Hereditary Genius,’ 1870.
Chap. v.
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noblest part of our nature. The surgeon may harden himself whilst performing an operation, for he knows that he is acting for the good of his patient ; but if we were intentionally to neglect the weak and helpless, it could only be for a contingent benefit, with a certain and great present evil. Hence we must bear without complaining 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 the weaker and inferior members of society not marrying so freely as the sound ; and this check might be inde- finitely increased, though this is more to be hoped foi than expected, by the weak in body or mind refraining from marriage.
In all civilised countries man accumulates property and bequeaths it to his children. So that the children in the same country do not by any means start fair in the race for success. But this is far from an unmixed evil ; for without the accumulation of capital the arts could not progress ; and it is chiefly through their power that the civilised races have extended, and are now everywhere extending, their range, so as to take the place °f the lower races. Nor does the moderate accumulation °f wealth interfere with the process of selection. When a poor man becomes rich, his children enter trades or Professions in which there is struggle enough, so that the able in body and mind succeed best. 1 he presence of a body of well-instructed men, who have not to labour 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 depends, not to mention other and higher advantages. No doubt wealth when very great tends to convert men into useless drones, but their number is never large ; and some degree of elimi-
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Pakt X.
nation here occurs, as we daily see rich men, who happen to be fools or profligate, squandering away all their wealth.
Primogeniture with entailed estates is a more direct evil, though it may formerly have been a great advan- tage by the creation of a dominant class, and any government is better than anarchy. The eldest sons, though they may be weak in body or mind, generally marry, whilst the younger sons, however superior in these respects, do not so generally marry. Nor can worthless eldest sons with entailed estates squander their wealth. But here, as elsewhere, the relations of civilised life are so complex that some compensatory checks intervene. The men who are rich through primogeniture are able to select generation after generation the more beautiful and charming women; and these must generally be healthy in body and active in mind. The evil con- sequences, such as they may be, of the continued pre- servation ol 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 shewn,12 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 supe- riority of any kind.
Although civilisation thus checks in many ways the action of natural selection, it apparently favours, by means of improved food and the freedom from occa- sional hardships, the better development of the body. This may be inferred from civilised men having been
12 ‘Hereditary Genius,’ 1S70, p. 132-140.
Chap. V.
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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 expeditious. Even the great luxury of the rich can be tut little detrimental ; for the expectation of life of our aristocracy, at all ages and ol both sexes, is very little Inferior to that of healthy English lives in the lower classes.13
\\ o will now loot to the intellectual faculties alone. If in each grade of society the members weie divided into two equal bodies, the one including the intel- lectually superior and the other the inferior, there can be little doubt that the former would succeed best in all occupations and rear a greater number of children. Even in the lowest walks of life, skill and ability must be of some advantage, though in many occupations, owing to the great division of labour, a very small one. Hence in civilised nations there will be some tendency to an increase both in the number and iu the standard of the intellectually able. But I do not Wish to assert that this tendency may not ho more than counterbalanced iu other ways, as by the multiplication of the reckless and improvident ; but even to such as these, ability must he some advantage.
It has often been objected to views like the fore- going, that the most eminent men who have ever lived have left no offspring to inherit their great intellect. ■Mr. Galton says,14 “ I regret I am unable to solve the ‘ simple question whether, and how far, men and women 1 who are prodigies of genius are infertile. I have, how- 1 ever, shewn that men of eminence are by no means so.
13 See the fifth and sixth columns, compiled from good authorities, ia the table given in Mr. E. R. Lankester’s ‘ Comparative Longevity,’ ls~0, p. 115.
14 1 Hereditary Genius,’ 1870, p. 330.
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THE DESCENT OF MAN.
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Great lawgivers, the founders of beneficent religions, great philosophers and discoverers in science, aid the progress of mankind in a far higher degree by their works than by leaving a numerous progeny. In the case of corporeal structures, it is the selection of the slightly better-endowed and the elimination of the slightly less well-endowed individuals, and not the pre- servation of strongly-marked and rare anomalies, that leads to the advancement of a species.15 So it will be with the intellectual faculties, namely from the some- what more able men in each grade of society succeeding rather better than the less able, and consequently in- creasing in number, if not otherwise prevented. When in any nation the standard of intellect and the number of intellectual men have increased, we may expect from the law of the deviation from an average, as shewn by Mr. Galton, that prodigies of genius will appear some- what more frequently than before.
In regard to the moral qualities, some elimination of the worst dispositions is always in progress even in the most civilised nations. Malefactors are executed, or imprisoned for long periods, so that they cannot freely transmit their bad qualities. Melancholic and insane persons are confined, or commit suicide. Violent and quarrelsome men often come to a bloody end. Restless men who will not follow any steady occupation — and this relic of barbarism is a great check to civilisation16 — emigrate to newly-settled countries, where they prove useful pioneers. Intemperance is so highly destructive, that the expectation of life of the intemperate, at the age, for instance, of thirty, is only l.'l'S years ; whilst for the rural labourers of England at the same a°n it is
15 ‘ Origin of Species’ (fifth edition, 1SG3), p. 104. ls ‘Hereditary Genius,’ 1S70, p. 847.
Chap. v.
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4059 years.17 Profligate women bear few children, and profligate men rarely marry; both suffer from disease. In the breeding of domestic animals, the elimination of those individuals, though few in number, which are in any marked manner inferior, is by no means an unim- portant element towards success. This especially holds good with injurious characters which tend to reappear through reversion, such as blackness in sheep ; and with mankind some of the worst dispositions, which occasionally without any assignable cause make their Appearance in families, may perhaps be reversions to a savage state, from which wre are not removed by very many generations. This view seems indeed recognised m the common expression that such men are the black sheep of the family.
With civilised nations, as far as an advanced stand- ard of morality, and an increased number of fairly Well-endowed men are concerned, natural selection ap- parently effects but little; though the fundamental social instincts were originally thus gained. But I have already said enough, whilst treating of the lower races, on the causes which lead to the advance of morality, namely, the approbation of our fellow-men — the strengthening of our sympathies by habit — example and imitation — reason — experience and even self-inte- rest— instruction during youth, and religious feelings.
A most important obstacle in civilised countries to aw increase in the number of men of a superior class has been strongly urged by Mr. Greg and Mr. Galton,ls
" E. Kay Lankester, ‘Comparative Longevity,’ 1870, p.115. The able of tli© intemperate is from Neison's ‘Vital Statistics.’ In regard to profligacy, sec Dr. Farr, “ Influence of Marriage on Mortality,” • Nat. Ass°c. for the Promotion of Social Science,’ 1S58.
18 ‘ Fraser’s Magazine,’ Sept. 1868, p. 353. ‘ Macmillan’s Magazine,’ Aug. 1865, p. 318. The Rev. F. W. Farrar (‘ Fraser’s Mag.,’ Aug. 1870, 0- 264) taUeB a different view.
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THE DESCENT OF MAN.
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namely, the fact that the very poor and reckless, who are often degraded by vice, almost invariably marry early, whilst the careful and frugal, who are generally otherwise virtuous, marry late in life, so that they may be able to support themselves and their children in comfort. Those who marry early produce within a given period not only a greater number of generations, but, as shewn by Dr. Duncan,10 they produce many more children. The children, moreover, that are born by mothers during the prime of life are heavier and larger, and therefore probably more vigorous, than those born at other periods. Thus the reckless, degraded, and often vicious members of society, tend to iucrease at a quicker rate than the provident and generally virtuous members. Or as Mr. Greg puts the case : “ The care- “ less, squalid, unaspiring Irishman multiplies like “ rabbits : the frugal, foreseeing, self-respecting, am- bitious Scot, stern in his morality, spiritual in his “faith, sagacious and disciplined in his intelligence, “passes his best years in struggle and in celibacy, “marries late, and leaves few behind him. Given a “ land originally peopled by a thousand Saxons and a “ thousand Celts — and in a dozen generations five-sixths “ of the population would be Celts, but five-sixths ot “the property, of the power, of the intellect, would “ belong to the one-sixth of Saxons that remained. “ In the eternal ‘ struggle for existence,’ it would be “ the inferior and less favoured race that had prevailed “ — and prevailed by virtue not of its good qualities “ but of its faults.”
There are, however, some checks to this downward tendency. We have seen that the intemperate suffer
10 “On the Laws of the Fertility of Women,” in ‘Transact. Roj'h Soc.’ Edinburgh, vol. xxiv. p. 287. See, also, Mr. Galton, ‘ Hereditary Genius,’ p. 352-357, for observations to the above effect.
Chap. V.
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from a high rate of mortality, and tlie extremely pro- fligate leave few offspring. The poorest classes crowd into towns, and it has been proved by Dr. Stark from the statistics of ten years in Scotland,30 that at all ages the death-rate is higher in towns than in rural districts, “and during the first live years of life the town death- “ rate is almost exactly double that of the rural districts.” As these returns include both the rich and the poor, no doubt more than double the number of births would be requisite to keep up the number of the very poor inha- bitants in the towns, relatively to those in the country. M ith women, marriage at too early an age is highly injurious ; for it has been found in France that, “ twice “ as many wives under twenty die in the year, as died out “ of the same number of the unmarried.” The mortality, ulso, of husbands under twenty is “ excessively high,” 21 hut what the cause of this may be seems doubtful. Lastly, if the men who prudently delay marrying until they can bring up their families in comfort, were to select, as they often do, women in the prime of life, the rate of increase in the better class would be only slightly lessened.
It was established from an enormous body of statistics, taken during 1853, that the unmarried men throughout Ifr'ance, between the ages of twenty and eighty, die in a ruuch larger proportion than the married : for instance, °ut of every 1000 unmarried men, between the ages of twenty and thirty, 11*3 annually died, whilst of the Carried only 6-5 died.22 A similar law was proved to
20 1 Tenth Annual Report of Births, Deaths, &c., in Scotland,’ 1S67, P' xxix.
21 These quotations are taken from our highest authority on such laestions, namely, Dr. Farr, in his paper “ On the Influence of Marriage ;’ri the Mortality of the French People,” read before the Nat. Assoc, ««* Promotion of Social Science, 1858.
22 Dr. Farr, ibid. The quotations given below are extracted from he same striking paper.
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hold good, during the years 1863 and 1861, with the entire population above the age of twenty in Scotland : for instance, out of every 1000 unmarried men, between the ages of twenty and thirty, 14*97 annually died, whilst of tho married only 7*21 died, that is less than half.23 Dr. Stark remarks on this, “Bachelorhood is “ more destructive to life than the most unwholesome “ trades, or than residence in an unwholesome house or “ district where there has never been tho most distant “ attempt at sanitary improvement.” He considers that the lessened mortality is the direct result of “ marriage, “ and the more regular domestic habits which attend that “ state.” He admits, however, that the intemperate, profligate, and criminal classes, whose duration of life is low, do not commonly marry; and it must like- wise be admitted that men with a weak constitution, ill health, or any great infirmity in body or mind, will often not w ish to marry, or will be rejected. Dr. Stark seems to have come to the conclusion that marriage in itself is a main cause of prolonged life, from finding that aged married men still have a considerable advan- tage in this respect over the unmarried of the same advanced age ; but every one must have known instances of men, who with weak health during youth did not marry, and yet have survived to old age, though remaining weak and therefore always with a lessened chance of life. There is another remarkable circum- stance which seems to support Dr. Stark’s conclusion, namely, that widows and widowers in France suffer in comparison with the married a very heavy rate of mor- tality ; hut Dr. Farr attributes this to the poverty and
23 I have taken the mean of the quinquennial means, given in ‘ The Tenth Annual Roport of Births, Deaths, &c., in Scotland,’ 1867. The quotation from Dr. Stark is copied from an article in the ‘ Daily News, Oct. 17th, 1868, which Dr. Farr considers very carefully written.
Chap. V.
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177
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 unmar- ried men, which seems to be a general law, “ is mainly “ due to the constant elimination of imperfect types, and “ to the skilful selection of the finest individuals out of “ each successive generation;” the selection relating only to the marriage state, and acting on all corporeal, in- tellectual, and moral qualities. We may, therefore, infer that sound and good men who out of prudence remain for a time unmarried do not suffer a high rate °f mortality.
If the various checks specified in the two last para- graphs, 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 retro- grade, as has occurred too often in the history of the "’or Id. We must remember that progress is no invari- aUe rule. It is most difficult to say why one civilised ration rises, becomes more powerful, and spreads more "’idely, than another; or why the same nation progresses more at one time than at another. We can only say that it depends on an increase in the actual number of the population, on the number of the men endowed 'vith high intellectual and moral faculties, as well as 011 their standard of excellence. Corporeal structure, eXcept so far as vigour of body leads to vigour of mind, aPpears to have little influence.
It has been urged by several writers that as high mtellectual powers are advantageous to a nation, the °hl Greeks, who stood some grades higher in intellect than any race that has ever existed,24 ought to have
14 See the ingenious and original argument on this subject by Mr.
ahon, ‘ Hereditary Genius,’ p. 310-342.
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risen, if the power of natural selection were real, 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 towards continued development in mind and body. But development of all kinds depends on many concurrent favourable cir- cumstances. Natural selection acts only in a tentative manner. Individuals and races may have acquired certain indisputable advantages, and yet have perished from failing in other characters. The Greeks may have retrograded from a want of coherence between the many small states, from the small size of their whole country, from the practice of slavery, or from extreme sensuality ; for they did not succumb until “they were enervated “ and corrupt to the very core” 26 The western nations of Europe, who now so immeasurably surpass their former savage progenitors and stand at the summit of civilisation, owe little or none of their superiority to direct inheritance from the old Greeks; though they owe much to the written works of this wonderful people.
Who can positively say why the Spanish nation, so dominant at one time, has been distanced in the race. The awakening of the nations of Europe from the dark ages is a still more perplexing problem. At this early period, as Mr. Galton26 has remarked, almost all the men of a gentle nature, those given to medi- tation or culture of the mind, had no refuge except m the bosom of the Church which demanded celibacy ;
25 Mr. Grog, ■ Fraser's Magazine,’ Sept. 1868, p. 357.
26 ‘Hereditary Genius,’ 1870, p. 357-359. The Eev. F. H. Farrar (‘ Fraser’s Mag.’, Aug. 1870, p. 257) advances arguments on the other side. Sir C. I, yell had already (‘Principles of Geology,’ vol. ii. 1^,K'‘ p. 489) called attention, in a striking passage, to the evil influence o the Holy Inquisition in having lowered, through selection, the genera standard of intelligence in Europe.
Chap. y.
CIVILISED NATIONS.
179
and this could hardly fail to have had a deteriorating mfluence on each successive generation. During this same period the Holy Inquisition selected with extreme care the freest and boldest men in order to burn or imprison them. In Spain alone some of the best men — those who doubted and questioned, and without doubting there can be no progress — were eliminated during three centuries at the rate of a thousand a year. The evil "Inch the Catholic Church has thus effected, though Ho doubt counterbalanced to a certain, perhaps large extent in other ways, is incalculable; nevertheless, Europe has progressed at an unparalleled rate.
The remarkable success of the English as colonists °ver other European nations, which is well illustrated by comparing the progress of the Canadians of English and Erench extraction, has been ascribed to their “ daring “ and persistent energy ; ” but wbo can say how the English gained their energy. There is apparently much truth in the belief that the wonderful progress the United States, as well as the character of the People, are the results of natural selection ; the more energetic, restless, and courageous men from all parts °f Europe having emigrated during the last ten or twelve generations to that great country, and having there succeeded best.27 Looking to the distant future, I do Hot think that the Rev. Mr. Zincke takes an exaggerated view when he says :28 “ 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 as subsidiary to ... . the great stream of Anglo-Saxon emigration to the west.”
7 Mr. Galton, ‘ Macmillan’s Magazine,’ August, 18G5, p. 325. See a s°> ‘ Nature,’ “ On Darwinism and National Life,” Dee. 1869, p. 184.
‘ Last Winter in the United States,’ 1868, p. 29.
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THE DESCENT OF MAN.
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Obscure as is tbe problem of the advance of civilisation, we can at least see that a nation which produced during a lengthened period the greatest number of highly intel- lectual, energetic, brave, patriotic, and benevolent men, would generally prevail over less favoured nations.
Natural selection follows from the struggle for exist- ence ; and this from a rapid rate of increase. It is impossible not bitterly to regret, but whether wisely is another question, the rate at which man tends to increase ; for this leads in barbarous tribes to infan- ticide and many other evils, and in civilised nations to abject poverty, celibacy, and to the late marriages of the prudent. But as man suffers from the same physical evils with the lower animals, he has no right to expect an immunity from the evils consequent on the struggle for existence. Had lie not been subjected to natural selection, assuredly he would never have attained to the rank of manhood. When we see in many parts of the world enormous areas of the most fertile land peopled by a few wandering savages, but which are capable of supporting numerous happy homes, it might be argued that the strugglo for existence had not been sufficiently severe to force man upwards to his highest standard. Judging from all that we know of man and the lower animals, there has always been sufficient variability in the intellectual and moral faculties, f°r their steady advancement through natural selection. No doubt such advancement demands many favourable concurrent circumstances ; but it may well be doubted whether the most favourable would have sufficed, had not the rate of increase been rapid, and the consequent
struggle for existence severe to an extreme degree.
On the evidence that all civilised nations were once baf- barous. — As we have had to consider the steps by which
Chap. V.
CIVILISED NATIONS.
181
some semi-human creature has been gradually raised to the rank of man in his most perfect state, the present subject cannot be quite passed over. But it has been treated in so full and admirable a manner by Sir J. Lubbock,'29 Mr. Tylor, Mr. McLennan, and others, that I need here give oidy the briefest summary of their results. The arguments recently advanced by the Luke of Argyll 30 and formerly by Archbishop Whately, in favour of the belief that man came into the world us a civilised being and that all savages have since undergone degradation, seem to me weak in comparison "ith those advanced on the other side. Many nations, no doubt, have fallen away in civilisation, and some uiay have lapsed into utter barbarism, though on this latter head I have not met with any evidence. The Luegians were probably compelled by other conquering hordes to settle in their inhospitable country, and they ruay 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 huest parts of Brazil.
The evidence that all civilised nations are the de- fendants of barbarians, consists, on the one side, of °lear traces of their former low condition in still-existing °Ustoms, beliefs, language, &c. ; and on the other side, °f proofs that savages are independently able to raise themselves a few steps in the scale of civilisation, and have actually thus risen. The evidence on the first head is extremely curious, but cannot be here given : I refer to such cases as that, for instance, of the art of euumorat ion, which, as Mr. Tylor clearly shows by the "ords still used in some places, originated in counting
29 ‘ On the Origin of Civilisation,’ ‘ Proc. Ethnological Soc.’ Nov. ^6, 18G7.
39 ‘ Primeval Man,’ 1S69.
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THE DESCENT OP MAN.
Part l.
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, which after reaching to the number V., change into VI., &c., when the other hand no doubt wTas used. So again, “ when we speak of three-score and ten, we are count- “ iug by the vigesimal system, each score thus ideally “ made, standing for 20 — for ‘ one man ’ as a Mexican “ or Carib would put it.” 31 According to a large and increasing school of philologists, every language bears the marks of its slow and gradual evolution. So it is with the art of writing, as letters are rudiments of pictorial representations. It is hardly possible to read Mr. M‘Lennan’s work32 and not admit that almost all civilised nations still retain some traces of such rude habits as the forcible capture of wives. What ancient nation, as the same author asks, can be named that was originally monogamous ? The primitive idea of justice, as shewn by the law of battle and other customs of which traces still remain, was likewise most rude. Many existing superstitions are the remnants of former false religious beliefs. Tho highest form of religion — the grand idea of God hating sin and loving righteousness — was unknown during primeval times.
Turning to the other kind of evidence : Sir J. Lub- bock has shewn that some savages have recently ini' proved a little in some of their simpler arts. From the
31 ‘ Koval Institution of Great Britain,’ Marcli 15, 1867. Also, ‘ Researches into tho Early History of Mankind,’ 1865.
32 ‘ Primitive Marriage,’ 1S65. See, likewise, an excellent article, evidently ky the same author, in the ‘ North British Review,’ July, 1SG9. Also, Mr. L. H. Morgan, “ A Conjectural Solution of the Origin of the Class. System of Relationship,” in ‘ Proc. American Acad, of Sciences,’ vol. vii. Peb. 1868. Prof. Schaaffhausen (‘ Autliropolog- Review,’ Oct. 186!),- p. 373) remarks on “the vestiges of human sacri- “ fices found both in Homer aud the Old Testament.”
Chap. V.
CIVILISED NATIONS.
183
extremely curious account which he gives of the weapons, tools, and arts, used or practised by savages in various parts of the world, it cannot be doubted that these have nearly all been independent discoveries, excepting per- haps the art of making fire.33 The Australian boomerang is a good instance of one such independent discovery. The Tahitians when first visited had advanced in many respects beyond the inhabitants of most of the other Polynesian islands. There are no just grounds for the belief that the high culture of the native Peruvians and Mexicans was derived from any foreign source ; 34 many native plants were there cultivated, and a few Dative animals domesticated. We should bear in mind that a wandering crew from some semi-civilised land, if washed to the shores of America, would not, judging from the small influence of most missionaries, have pro- duced any marked effect on the natives, unless they had already become somewhat advanced. Looking to a very remote period in the history of the world, we find, to Dse 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. fa 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 oi 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 floubt that the inhabitants of these many countries, which include nearly the whole civilised world, were once in a barbarous condition. To believe that man was abori-
33 Sir J. Lubbock, * Prehistoric Times,’ 2nd edit. 1869, chap. xv. and Xvt et passim.
34 Dr. P, Muller has made some good remarks to this effect in the ‘ Reise del- Novara : Anthropolog. Theil,’ Abtheil. iii. 18G8, s. 127.
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THE DESCENT OF MAN.
Part I.
ginally civilised and then suffered utter degradation in so many regions, is to take a pitiably low view of human nature. It is apparently a truer and more cheerful view that progress has been much more general than retrogression ; that man has risen, though by slow and interrupted steps, from a lowly condition to the highest standard as yet attained by him in knowledge, morals, and religion.
AFFINITIES AND GENEALOGY.
185
Ohaj>. VI. j
CHAPTEK YI.
On the Affinities and Genealogy of Man.
Position of man in the animal series — The natural system genea- logical— Adaptive characters of slight value Various small points of resemblance between man and the Quadrumana Rank of man in the natural system — Birthplace and antiquity of man — Absence of fossil connecting-links — Lower stages in the genealogy of man, as iulerrcd, firstly irom his affinities and secondly from his structure — Early androgynous condition of the Yertebrata — Conclusion.
Even if it be granted that the difference between man ^d bis nearest allies is as great in corporeal structure as some naturalists maintain, and although we must grant that the difference between them is immense in mental Power, yet the facts given in the previous chapters declare, as it appears to me, in the plainest manner, that man is descended from some lower form, notwith- standing that connecting-links have not hitherto been discovered.
Man is liable to numerous, slight, and diversified variations, which are induced by the same general causes, are governed and transmitted in accordance "ith the same general laws, as in the lower animals. Man tends to multiply at so rapid a rate that his off- spring are necessarily exposed to a struggle tor existence, and consequently to natural selection. He 1ms given Hse to many races, some of which are so different that they have often been ranked by naturalists as distinct species. His body is constructed on the same homo- logical plan as that of other mammals, independently of the uses to which the several parts may he put. He
186
THE DESCENT OP MAN.
Part L
passes through the same phases of embryological de- velopment. He retains many rudimentary and useless structures, which no doubt were once serviceable. Cha- racters occasionally make their re-appearance in him, which we have every reason to believe were possessed by his early progenitors. If the origin of man had been wholly different from that of all other animals, these various appearances would be mere empty deceptions ; but such an admission is incredible. These appearances, on the other hand, are intelligible, at least to a large extent, if man is the co-descendant with other mammals of some unknown and lower form.
Some naturalists, from being deeply impressed with the mental and spiritual powers of man, have divided the whole organic world into three kingdoms, the Human, the Animal, and the Vegetable, thus giving to man a separate kingdom.1 Spiritual powers cannot be com- pared or classed by the naturalist ; but he may endea- vour to shew, as I have done, that the mental faculties of man and the lower animals do not differ in kind, although immensely in degree. A difference in degree, however great, does not justify us in placing man in a distinct kingdom, as will perhaps be best illustrated by comparing the mental powers of two insects, namely, a coccus or scale-insect and an ant, which undoubt- edly belong to the same class. The difference is here greater, though of a somewhat different kind, than that between man and the highest mammal. The female coccus, whilst young, attaches itself by its pro- boscis to a plant; sucks the sap but never moves again; is fertilised and lays eggs ; and this is its whole history. On the other hand, to describe the habits and mental
1 Isidore Geoffroy St.-Hilaire gives a detailed account of the position assigned to man by various naturalists in their classifications : ‘ Hist* Nat. Gen.’ tom. ii. 1859, p. 170-1S9.
Chap. VI.
AFFINITIES AND GENEALOGY.
187
powers of a female ant, would require, as Pierre Huber bas shewn, a large volume; I may, however, briefly specify a few points. Ants communicate information to each other, and several unite for the same work, or games of play. They recognise their fellow-ants after months of absence. They build great edifices, keep them clean, close the doors in tbe evening, and post sentries. They make roads, and even tunnels under rivers. They collect food for the community, and when an object, too large for entrance, is brought to the nest, they enlarge the door, and afterwards build it up again.2 They go out to battle in regular bands, and freely sacrifice their lives for the common Weal. They emigrate in accordance with a precon- certed plan. They capture slaves. They keep Aphides as milch-cows. 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 them in distinct classes, much less in distinct kingdoms. No doubt this interval is bridged over by the intermediate mental powers of many other insects ; and this is not the case with man and the higher apes. But we have every reason to believe that breaks in the series are simply the result of many forms having be- come extinct.
Professor 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 be places both the marsupials and the monotremata ; so that he makes man as distinct from all other mam-
2 See the very interesting article, u L’Instinct chez les Insectes,” by George Pouohet, ‘ Kevue des Deux Mondes,’ Feb. 1870, p. 682.
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THE DESCENT OP MAN.
Part I.
mals 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 judg- ment, and therefore need not here be further con- sidered.
We can understand why a classification founded on any single character or organ — even an organ so won- derfully 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 arrangement proved thoroughly artificial.3 Classifications may, of course, be based on any character whatever, as on size, colour, or the element inhabited ; but naturalists have long felt a profound conviction that there is a natural system. This system, it is now generally admitted, must be, as far as possible, genealogical in arrangement, — that is, the co-descendants ol tire same form must be kept together in one group, separate from the co-descendants of any other form ; but if the parent-forms are related, 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 — will be expressed by such terms as genera, families, orders, and classes. As we have no record of the lines of descent, these lines can be discovered only by observing the degrees of re- semblance between the beings which are to be classed. For this object numerous points of resemblance are of much more importance than the amount of similarity or dissimilarity in a few points. If two languages were found to resemble each other in a multitude of
Westwood, * Modern Class, of Insects,’ vol. ii. 1810, p. 87.
Chap. VI.
AFFINITIES AND GENEALOGY.
189
words and points of construction, they would be uni- versally recognised as having sprung from a common source, notwithstanding that they differed greatly in some few words or points of construction. But with organic beings the points of resemblance must not con- sist of adaptations to similar habits of life : two animals may, for instance, have had their whole frames modified for living in the water, and yet they will not be brought any nearer to each other in the natural system. Hence We can see how it is that resemblances in unimportant structures, in useless and rudimentary organs, and in parts not as yet fully developed or functionally active, 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 modifi- cation 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 lias already, according to the theory of evolution, varied much ; consequently it would (as long as the organism remained exposed to the same exciting con- ditions) be liable to further variations of the same kind ; and these, if beneficial, would be preserved, and thus continually augmented. In many cases the continued development of a part, for instance, ot the beak of a bird, or of the teeth of a mammal, would not be advan- tageous to the species for gaining its food, or for any ether object ; hut with man we can see no definite limit, as far as advantage is concerned, to the continued de- velopment of the brain and mental faculties, therefore in determining the position of man in the natural or genealogical system, the extreme development of his brain ought not to outweigh a multitude of resem-
190
THE DESCENT OP MAN.
Part I.
blances in other less important or quite unimportant points.
The greater number of naturalists who have taken into consideration the whole structure of man, including his mental faculties, have followed Blumenbach. and Cuvier, and have placed man in a separate Order, under the title of the Biman a, and therefore on an equality with the Orders of the Quadrumana, Carnivora, &c. Recently many of our best naturalists have recurred to the view first propounded by Linnreus, 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 if, in the first place, wo bear in mind the remarks just made on the comparatively small importance for classi- fication of the great development of the brain in man ; bearing, also, in mind that the strongly-marked differ- ences between the skulls ol man and the Quadrumana (lately insisted upon by Bischoff, Aeby, and others) apparently follow from their differently developed brains. In the second place, we must remember that nearly all the other and more important differences between man and the Quadrumana are manifestly adaptive in their nature, and relate chiefly to the erect position of man ; such as the structure of his hand, foot, and pelvis, the curvature of his spine, and the position of his head. The family of seals offers a good illustration of the small importance of adaptive characters for classification. These animals differ from all other Carnivora in the form of their bodies and in the structure of their limbs, far more than does man from the higher apes ; yet in every system, from that of Cuvier to the most recent one by Mr. Flower,4 seals are ranked as a mere family
* ‘ Proo. Zoolog. Soo.’ 1869, p. 4.
Chap. YI. AFFINITIES AND GENEALOGY. 191
111 the Order of the Carnivora. If man had not been his own classifier, lie would never have thought of founding a separate order for his own reception.
It would be beyond my limits, and quite beyond my knowledge, even to name the innumerable points of structure in which man agrees with the other Primates. Our great anatomist and philosopher. Prof. Huxley, has fully discussed this subject.5 and lias come to the con- clusion that man in all parts of his organisation differs less from the higher apes, than these do from the lower uiembers of the same group. Consequently there “ is “ no justification for placing man in a distinct order.”
In an early part of this volume I brought forward Various facts, shewing how closely man agrees in con- 8titution with the higher mammals ; and this agreement, Uo doubt, depends on our close similarity in minute structure and chemical composition. I gave, as ^stances, our liability to the same diseases, and to the uttaclcs of allied parasites ; our tastes in common for the 8atne stimulants, and the similar effects thus produced, as Well as by various drugs ; and other such facts.
As small unimportant points of resemblance between 111 fui and the higher apes are not commonly noticed in 8ystematic works, and as, when numerous, they clearly I’cveal our relationship, I will specify a few such points. Ike relative position of the features is manifestly the sa®e in man and the Quadrumana; and the various eiUotions are displayed by nearly similar movements of *he muscles and skin, chiefly above the eyebrows and '"’•'id the mouth. Some few expressions are, indeed, aVost the same, as in the weeping of certain kinds of ’"°nkeys, and in the laughing noise made by others.
' Ul'ing which the corners of the mouth are drawn back-
‘ Evidence as to Man’s Place in Nature,’ 1863, p. 70, et passim.
192
THE DESCENT OF MAH.
Part I-
wards, and the lower eyelids wrinkled. The external ears are curiously alike. In man the nose is much more prominent than in most monkeys ; hut we may trace the commencement of an aquiline curvature in the nose of the Hoolock Gibbon ; and this in the Sem- nopithecus nasioa, is carried to a ridiculous extreme.
The faces of many monkeys are ornamented with beards, whiskers, or moustaches. The hair on the head grows to a great length in some species of Semno- pithecus ; 6 and in the Bonnet monkey ( Macacus radiatus) it radiates from a point on the crown, with a parting down the middle, as in man. It is commonly said that the forehead gives to man his noble and intel- lectual appearance ; but the thick hair on the head of the Bonnet monkey terminates abruptly downwards, and is succeeded by such short and fine hair, or down, that at a little distance the forehead, with the exception of the eyebrows, appears quite naked. It lias been erroneously asserted that eyebrows are not present in any monkey. In the species just named the degree of nakedness of the forehead differs in different individuals! and Eschricht states7 that in our children the lin'd between the hairy scalp and the naked forehead 18 9 sometimes not well defined ; so that here we seem to have a trifling case of reversion to a progenitor, in whom the forehead had not as yet become quite naked.
It is well known that tho hair on our arms tends to converge from above and below to a point at the el bo" • This curious arrangement, so unlike that in most of the lower mammals, is common to the gorilla, chimpanzee, orang, some species of Hylobates, and even to some few' American monkeys. But in Hylobates agilis the ha"
8 Isid. Geoffroy, ‘ Hist. Nat. Gen.’ tom. ii. 1850, p. 217.
’ “ Ueber die Kichtung der Haare,” &c., Muller’s ‘ Areliiv fiir Ana und Phys.’ 1837, s. 51.
Chap. yi.
AFFINITIES AND GENEALOGY.
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°u the fore-arm is directed downwards or towards the "'list in the ordinary manner ; and in II. lar it is nearly G1’ect, 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 and its direction on the back is "dapted to throw off the rain ; even the transverse hairs °n the fore-legs of a dog may serve for this end when he is coiled up asleep. Mr, Wallace remarks that the con- vergence of the hair towards the elbow on the arms of the oraug (whose habits he has so carefully studied) serves to throw off the rain, when, as is the custom °I this animal, the arms are bent, with the hands "lasped round a branch or over its own head. We should, however, bear in mind that the attitude of an auiinal may perhaps be in part determined by the direction of the hair ; and not the direction of the hair h}’ the attitude. If the above explanation is correct in ihe case of the orang, the hair on our fore-arms offers a ""lions record of our former state ; for no one supposes that it is now of any use in throwing off the rain, nor in °1"' 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 Eschrickt of the arrange- ment of the hair on the human foetus (this being the 8a®e as in the adult) and not agree with this excellent observer that other and more complex causes have intervened. The points of convergence seem to stand 111 some relation to those points in the embryo which ai'e last closed in during development. There appears, als°, to exist some relation between the arrangement
VOL. I. 0
191
THE DESCENT OF MAN.
Part X.
of the hair on the limbs, and the course of the medullary arteries.8
It must not be supposed that the resemblances be- tween man and certain apes in the above and many other points — such as in having a naked forehead, long tresses on the head, &c. — are all necessarily the result of unbroken inheritance from a common pro- genitor thus characterised, or of subsequent reversion. Many of these resemblances are more probably due to analogous variation, which follows, as I have else- where attempted to shew,8 from co-descended organisms having a similar constitution and having been acted on by similar causes inducing variability. With re- spect to the similar direction of the hair on the fore- arms of man and certain monkeys, as this character is common to almost all the anthropomorphous apes, it may probably be attributed to inheritance; but not certainly so, as some very distinct American monkeys are thus characterised. The same remark is applicable to the tailless condition of man ; for the tail is absent in all the anthropomorphous apes. Nevertheless this character cannot with certainty be attributed to inheri- tance, as the tail, though not absent, is rudimentary in several other Old World and in some New World species, and is quite absent iu several species belonging to the allied group of Lemurs.
Although, as we have now seen, man has no just right to form a separate Order for his own reception, he m»V
8 On the hair in Hylobates, see ‘ Nat. Hist, of Mammals,’ hy 0- h- Martin, 1841, p. 415. Also, Isul. Geoffroy on the American monkey® and other kinds, ‘Hist. Nat. Gen.’ vol. ii. 1859, p. 216, 243. Bsch richt, ibid, s. 46, 55, 61. Owen, ‘ Anat. of Vertebrates,’ vol. iii. P- Wallace, ‘ Contributions to the Theory of Natural Selection,’ 1870, !’■ 344. _ .
* ‘ Origin of Species,’ 5th edit. 1869, p. 194. ‘ The Variation 0 Animals and Plants under Domestication,’ vol. ii. 1868, p. 348.
Chap. VI.
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perhaps claim a distinct Sub-order or Family. Prof. Huxley, in his last work,10 divides the Primates into three Sub-orders ; namely, the Anthropidae with man ■'done, the Simiadge including monkeys of all kinds, and t^e Lemuridae with the diversified genera of lemurs. As far as differences in certain important points of structure are concerned, man may no doubt rightly claim the Iank of a Sub-order ; and this rank is too low, if we look ehiefly to his mental faculties. Nevertheless, under a genealogical point of view it appears that this rank is too high, and that man ought to form merely a Family, °v possibly even only a Sub-family. If we imagine three lines of descent proceeding from a common source, Jt is quite conceivable that two of them might after the lapse of ages be so slightly changed as still to I'ornain as species of the same genus; whilst the third hre might become so greatly modified as to deserve t° rank as a distinct Sub-family, Family, or even Order. But in this case it is almost certain that the third line would still retain through inheritance Numerous small points of resemblance witli the other t'vo lines. Here then would occur the difficulty, at present insoluble, how much weight we ought to assign
our classifications to strongly-marked differences in ^°:ne 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. The former alternative is the lllost obvious, and perhaps the safest, though the latter appears the most correct as giving a truly natural
Hassification.
-lo torm a judgment on this head, with reference 0 Qlan we must glance at the classification of the
‘ An Introduction to the Classification of Animals,’ 1863, p. 99.
o 2
196' THE DESCENT OF MAN. Part I.
Simiadse. This family is divided by almost all natura- lists into the Catarhine group, or Old World monkeys, all of which are characterised (as their name expresses) by the peculiar structure of their nostrils and by having four premolars in each jaw; and into the Platvrhine group or New World monkeys (including two very distinct sub-groups), all of which are characterised by differently-constructed nostrils and by having six pre- molars in each jaw. Some other small differences might be mentioned. Now man unquestionably belongs in his dentition, in the structure of his nostrils, and some other respects, to the Catarhine or Old World division ; nor does he resemble the Platyrhines more closely than the Catarhines in any characters, excepting in a few of not much importance and apparently of an adaptive nature. Therefore it would be against all probability to suppose that some ancient New World species had varied, and had thus produced 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 offshoot from the Old World Simian stem : and that under a genealogical point of view, he must be classed with the Catarhine division.11
The anthropomoi-phous apes, namely the gorilla- chimpanzee, orang, and hylobates, are separated as a distinct sub-group from the other Old World monkeys by most naturalists. I am aware that Gratiolet, relying on the structure of the brain, does not admit the exist-
11 This is nearly the same classification as that provisionally adopted by Mr. St. George Mivart (‘ Transact. Philosoph. Soc.’ 1S67, p. 300), who, after separating the Lemuridre, divides the remainder of the Primates into the Hominidse, the Simiadse answering to the Catarhine-1 the Cebidse, and the Hapalidas, — these two latter groups answering to the Platyrhines.
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ence of this sub-group, and no doubt it is a broken ; thus the orang, as Mr. St. G. Mivart' remarks,12 ‘ is one of the most peculiar and aberrant forms to be “ iound in the Order.” The remaining, non-anthropo- ^orphous, 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 appears from M. Gaudry’s wonderful discoveries in Attica, that during the Miocene period a form existed there, which connected Semnopithecus and Macacus; a,id this probably illustrates the manner in which the °ther 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, Hot only in all those characters which he possesses in common with the whole Catarhine group, but in other Peculiar characters, such as the absence of a tail and °f callosities and in general appearance, we may infer Ihat some ancient member of the anthropomorphous sub-group gave birth to man. It is not probable *hut a member of one of the other lower sub-groups should, through the law of analogous variation, have §lven rise to a man-like creature, resembling the higher Hothropomorphous apes in so many respects. No houbt man, in comparison with most of his allies, has Undergone an extraordinary amount of modification, chiefly in consequence of his greatly developed brain ail(t erect position ; nevertheless we should bear in 111 hid that be “ is but one of several exceptional forms “ of Primates.”13
livery naturalist, who believes iu the principle of
12 ‘ Transact. Zoolog. Soc.’ vol, vi. 1867, p. 214.
13 Mr. St. G. Mivart, ‘ Transact. Phil. Soc.’ 1867, p. 410.
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THE DESCENT OF MAN.
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evolution, will grant that the two main divisions of the Siiuiadse, namely the Catarhine and Platyrhine mon- keys, with their sub-groups, have all proceeded from some one extremely ancient progenitor. The early descendants of this progenitor, before they had diverged to any considerable extent from each other, would 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 Catarhine and Platyrhine divi- sions. 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 Catarhine monkeys in one way and the Platyrhines m another way, but would have resembled in this respect the allied Lenin rid te which differ greatly from each other in the form of their muzzles,1,1 and to an extra- ordinary degree in their dentition.
The Catarhine and Platyrhine monkeys agree m a multitude of characters, as is shewn by their unques- tionably belonging to one and the same Order. The many characters which they possess in common can hardly have been independently acquired by so many distinct species; so that these characters must have been inherited. But an ancient form which possesse many characters common to the Catarhine and Plat)' rhine monkeys, and others in an intermediate condition* and some few perhaps distinct from those now present in either group, would undoubtedly have been ranked, if seen by a naturalist, as an ape or monkey. And as man under a genealogical point of view belongs to tin Catarhine or Old World stock, we must conclude, ho"'
14 Messrs. Mine and Mivart on the Lemuroidea, ‘Transact. Zoolon Soc.’ vol. vii. 1869, p. 5.
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ever much the conclusion may revolt our pride, that our early progenitors would have been properly thus designated.16 But we must not fall into the error of supposing that the early progenitor of the whole Simian stock, including man, was identical with, or even closely Resembled, any existing ape or monkey.
On the Birthplace and Antiquity of Man. li e are naturally led to enquire where was the birthplace of man at that stage of descent when our progenitors diverged from the Catarhine stock. -The lact that they belonged to this stock clearly shews that they inhabited the Old World ; but not Australia nor any oceanic island, as we may infer from the laws of geogra- phical distribution. In each great region of the world the living mammals are closely related to the extinct species of the same region. It is therefore probable that Africa was formerly inhabited by extinct apes closely allied to the gorilla and chimpanzee ; and as these two species are now man’s nearest allies, it is somewhat more probable that our early progenitors lived on the African continent than elsewhere. But it is useless to speculate on this subject, for an ape Dearly as large as a man, namely the Dryopithecus ol Lartet, which was closely allied to the anthropo- morphous Hylobates, existed in Europe during the Upper Miocene period ; and since so remote a period the earth has certainly undergone many great revo- lutions, and there has been ample time for migration °u the largest scale.
13 ITackel lias come to tliis same conclusion. See 4 Ucber die Ent- stehung des Menschengeschleehts,’ in Virchow’s 4 Sammlimg. gemein. wissen. Vortrage.’ 1868, s. 01. Also his 4 Natiirliche Schopfungs- Seschichte,’ 1868^ in which he gives in detail his views on the genea- logy of man.
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THE DESCENT OF MAN.
Past I-
At the period and place, whenever and wherever it may have been, when man first lost his hairy covering, he probably inhabited a hot country; and this would have been favourable for a frugiferous diet, on which, judging from analogy, he subsisted. We are far from knowing how long ago it was when man first diverged from the Catarhine stock ; but this may have occurred at an epoch as remote as the Eocene period; for the higher apes had diverged from the lower apes as early as the Upper Miocene period, as shewn by the existence of the Dryopithecus. We are also quite ignorant at how rapid a rate organisms, whether high or low in the scale, may under favourable circumstances be modified : wre know, however, that some have retained the same form during an enormous lapse of time. From what we see going on under domestication, we learn that within the same period some of the co-descendants of the same species may be not at all changed, some a little, and some greatly changed. Thus it may have been with man, who has undergone a great amount ot modification in certain characters in comparison with the higher apes.
The great break in the organic chain between man and his nearest allies, which cannot be bridged over by any extinct or living species, has often been ad- vanced 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, convinced by general reasons, believe in the general principl® of evolution. Breaks incessantly occur in all parts of the series, some being wide, sharp and defined, others less so in various degrees ; as between the orang and its nearest allies — between the Tarsius and the other Lemuridse — between the elephant and in a more striking manner between the Ornithorhynchus or
Chap. VI.
AFFINITIES AND GENEALOGY.
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Echidna, and other mammals. But all these breaks depend merely on the number of related forms which have become extinct. At some future period, not very distant as measured by centuries, the civilised races of man will almost certainly exterminate and replace throughout the world the savage races. At the same time the anthropomorphous apes, as Professor Schaaffhausen has remarked,16 will no doubt be exter- minated. The break will then be rendered wider, for it will intervene between man in a more civilised state, as we may hope, than the Caucasian, and some ape as low as a baboon, instead of as at present 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 will read Sir C. Lyell’s discussion,1' in which he shews that in all the vertebrate classes the discovery of fossil remains has been an extremely slow and fortuitous process. Nor should it be forgotten that those regions which are the most likely to afford remains connecting man with some extinct ape-like creature, have not as yet been searched by geologists.
Lower Stages in the Genealogy of JKan. We have seen that man appears to have diverged from the Oatarliine or Old World division of the SimiadcB, alter these had diverged from the New World division. We will now endeavour to follow the more remote traces of his genealogy, trusting in the first place to the mutual affinities between the various classes and orders, with sonre slight aid from the periods, as far as ascertained,
18 ‘Anthropological Keview,’ April, 1SG7, p. 23G.
17 ‘Elements of Geology,’ 1865, p. 583-585. ‘Antiquity of Man, 1863, p. H5.
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THE DESCENT OF MAN.
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of their successive appearance on the earth. The Lemuridse stand below and close to the Siraiadse, con- stituting a very distinct family of the Primates, or, according to Haekel, a distinct Order. This group is diversified and broken to an extraordinary degree, and includes many aberrant forms. It has, therefore, pro- bably suffered much extinction. Most of the remnants survive on islands, namely in Madagascar and in the islands of the Malayan archipelago, where they have not been exposed to such severe competition as they would have been on well-stocked continents. This group likewise presents many gradations, leading, as Huxley remarks,18 “ insensibly from the croivn and “ summit of the animal creation down to creatures “ from which there is but a step, as it seems, to the “ lowest, smallest, and least intelligent of the placental “ mammalia.” From these various considerations it is probable that the Simiadm were originally developed from the progenitors of the existing Lemuridse ; and these in their turn from forms standing very low in the mammalian series.
The Marsupials stand in many important characters below the placental mammals. They appeared at an earlier geological period, and their range was formerly much more extensive than what it nowr is. Hence the Placentata are generally supposed to have been derived from the I m placentata or Marsupials ; not, however, fro® forms closely like the existing Marsupials, but fro® their early progenitors. The Monotrcmata are plainly allied to the Marsupials ; forming a third and still lower division in the great mammalian series. They are represented at the present day solely by the Or®' thorhynchus and Echidna ; and these two forms may
18 1 Man’s Place in Nature,’ p. 105.
Chap. VI.
AFFINITIES AND GENEALOGY.
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be safely considered as relics of a much larger group ■which have been preserved in Australia through some favourable concurrence of circumstances. The Mono- tremata are eminently interesting, as in several important points of structure they lead towards the class of reptiles.
In attempting to trace the genealogy of the Mam- malia, and therefore of man, lower down in the series, we become involved in greater and greater obscurity. He who wishes to see what ingenuity and knowledge can effect, may consult Prof. Hackel’s works.19 I will content myself with a few general remarks. Every evolutionist will admit that the live great vertebrate classes, namely, mammals, birds, reptiles, amphibians, and fishes, are all descended from some one prototype ; for they have much in common, especially during their embryonic state. As the class of fishes is the most lowly organised and appeared before the others, we may conclude that all the members of the vertebrate king- dom are derived from some fish-like animal, less highly organised than any as yet found in the lowest known formations. The belief that animals so distinct as a monkey or elephant and a humming-bird, a snake, frog, and fish, &c., could all have sprung from the same parents, will appear monstrous to those who have not attended to the recent progress of natural history. 1 or fids belief implies the former existence of links closely binding together all these forms, now so utterly unlike.
19 Elaborate tables nni given in his ‘Generellc Morpliologie (B. ii. eliii. and s. 425) ; and with more especial reference to man in his Yu, lirliche Sohopfungsgescbiohte,’ 1S68. Prof. Huxley, in reviewing this latter work (‘The Academy,’ 1869, p. 42) says, that he considers the phylum or lines of descent of the Vertebrata to be admirably dis- eased by Hiiekel, although he differs on some points. He expresses, al»o. his high estimate of the value of the general tenor and spirit of the whole work.
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THE DESCENT OP MAN.
Pakt I.
Nevertheless it is certain that groups of animals have existed, or do now exist, which serve to connect more or less closely the several great vertebrate classes. We have seen that the Ornithorhynchus graduates towards reptiles ; and Prof. Huxley has made the remarkable discovery, confirmed by Mr. Cope and others, that the old Dinosaurians are intermediate in many important respects between certain reptiles and certain birds — the latter consisting of the ostrich-tribe (itself evidently a widely-diffused remnant of a larger group) and of the Archeopteryx, that strange Secondary bird having a long tail like that of the lizard. Again, according to Prof. Owen,20 the Iehthyosaurians — great sea-lizards fur- nished with paddles — present many affinities with fishes, or rather, according to Huxley, with amphibians. This latter class (including in its highest division frogs and toads) is plainly allied to the Ganoid fishes. These latter fishes swarmed during the earlier geological periods, and were constructed on what is called a highly generalised type, that is they presented diversified "affi- nities with other groups of organisms. The amphibians and fishes are also so closely united by the Lepidosiren, that naturalists long disputed in which of these two classes it ought to be placed. The Lepidosiren arid some few Ganoid fishes have been preserved from utter extinction by inhabiting our rivers, which are harbours of refuge, bearing the same relation to the great waters of the ocean that islands bear to continents.
Lastly, one single member of the immense and diver- sified class of fishes, namely the lancelet or amphioxus, is so different from all other fishes, that Hackel main- tains that it ought to form a distinct class in the vertebrate kingdom. This fish is remarkable for its
20 ‘ Palaeontology,’ 1860, p. 199.
Chap. VI.
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Negative characters ; it can hardly be said to possess a brain, vertebral column, or heart, &c. ; so that it was classed bv the older naturalists amongst the worms. Many years ago Prof. Goodsir perceived that the lancelet presented some affinities with the Ascidians, "hi cl i are invertebrate, hermaphrodite, marine crea- tures 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 amongst the Kermes or worms. Their larvae somewhat resemble tadpoles in shape,21 and have the power of swimming freely about. Some observations lately made by M. Kovalevsky,22 since confirmed by Prof. Kuppfer, will f°nn a discovery of extraordinary interest, if still further extended, as I hear from M. Kowalevsky in Naples he bas now effected. The discovery is that the larvae of Kscidians arc related to the Yertebrata, in their manner °f development, in the relative position of the nervous system, and in possessing a structure closely like the chorda dorsalis of vertebrate animals. It thus appears, b we may rely on embryology, which has always proved fhe safest guide in classification, that we have at last gained a clue to the source whence the Yertebrata have
21 I had the satisfaction of seeing, at the Falkland Islauda, in April, ^33, and therefore some years before any other naturalist, the loco- Motive larvre of a compound Ascidian, closely allied to, but apparently genetically distinct from, Synoicum. The tail 'was about five times as r,tlg as the oblong head, and terminated in a very tine filament. It )Vas plainly divided, as sketched by me under a simple microscope, by fans verse opaque partitions, which I presume represent the groat cells gured by Kowalevsky. At on early stage of development the tail was el°sely coiled round the head of the larva.
“ ‘Memoires de l’Acad. des Sciences de St. PeTershourg,’ tom. x. No- 15, 1866.
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THE DESCENT OF MAN.
Part I.
been derived. We should thus be justified in believing that at an extremely remote period a group of animals existed, resembling in many respects the larvae of our present Ascidians, which diverged into two great 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 Yertebrata.
We have thus far endeavoured rudely to trace the genealogy of the Yertebrata by the aid of their mutual affinities. We will now look to man as he exists ; and we shall, I think, be able partially to restore during successive periods, but not in due order of time, the structure of our early progenitors. This can be effected by means of the rudiments which man still retains, by the characters which occasionally make their appear- ance 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 were no doubt once covered with hail-, both sexes having beards ; their ears were 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 no"' only occasionally reappear, but are normally present in the Quadrumana. The great artery and nerve of the humerus ran through a supra-condyloid foramen. At this or some earlier period, the intestine gave forth a much larger diverticulum or caecum than that now existing. The foot, judging from the condition of the great toe in the foetus, was then prehensile; and our progenitors, no doubt, were arboreal in their habits, frequenting some warm, forest-clad land. The males
Chap. VI.
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Were provided with, 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 mem- brane. At a still earlier period the progenitors of man must have been aquatic in their habits ; for morpho- logy 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 bran- chiae once existed. At about this period the true kid- neys were replaced by the corpora wolffiana. The heart existed as a simple pulsating vessel; and the chorda dorsalis took the place of a vertebral column. These early predecessors of man, thus seen in the dim recesses °t time, must have been as lowly organised as the lance- Ict or amphioxus, or even still more lowly organised.
There is one other point deserving a fuller notice, bt has long been known that in the vertebrate king-
i o o
c*om one sex hears rudiments of various accessory Parts, appertaining to the reproductive system, which Properly belong to the opposite sex; and it lias now been ascertained that at a very early embryonic period both sexes possess true male and female glands. Hence S0)ne extremely remote progenitor of the whole verte- brate kingdom appears to have been hermaphrodite or androgynous.23 Hut here we encounter a singular difficulty. In the mammalian class the males possess
21 This is the conclusion of one of the Highest authorities in com- parative auatomy, namely, Prof. Gegenbaur : ‘Grnndziige dor vergleich. y1(lh 1871), g. 876. The result lias been arrived at chiefly from the s udy of the Amphibia ; but it appears from the researches of Waldeyer hls quoted in Humphry’s ‘ Journal of Auat. and Phys.’ 1869, p. 161), ,, t the sexual organs of even “ the higher vertebrata are, in tlieir early c°ndition, hermaphrodite.” Similar views have long been hold by s°tnc authors, though until recently not well based.
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THE DESCENT OF MAN.
Part I.
in their vesiculte prostraticae rudiments of a uterus with the adjacent passage ; they bear also rudiments of mammae, and some male marsupials have rudiments of a marsupial sack.24 Other analogous facts could be added. Are we, then, to suppose that some extremely ancient mammal possessed organs proper to both sexes, that is, continued androgynous after it had acquired the chief distinctions of its proper class, and therefore after it had diverged from the lower classes of the vertebrate kingdom ? This seems improbable in the highest degree; for had this been the case, we might have expected that some few members of the two lower classes, namely fishes25 and amphibians, would still have remained androgynous. We must, on the contrary, believe that when the five vertebrate classes diverged from their common progenitor the sexes had already become separated. To account, however, for male mammals possessing rudiments of the acces- sory female organs, and for female mammals possessing rudiments of the masculine organs, we need not suppose that their early progenitors were still androgynous after they had assumed their chief mammalian characters. It is quite possible that as the one sex gradually acquired the accessory organs proper to it, some of the successive steps or modifications were transmitted to the opposite sex. 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,
2< The male Thylocinus offers the best instance. Owen, ‘ Anatomy of Vertebrates,’ vol. iii. p. 771.
25 Serranus is well known often to bo in an hermaphrodite condition with the organs proper to both sexes symmetrically developed. Several excellent naturalists are convinced that this is the normal condition , hut Dr. Gunther, as he informs me, does not believe that tiffs is the case. Descent from an ancient androgynous prototype would, however, naturally favour and explain, to u certain extent, the frequent recur- rence in these fishes of this condition, if it be abnormal.
Chap. VI.
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and brilliant colours, acquired by male birds for battle or ornament, and transferred to the females in an im- perfect or rudimentary condition.
The possession by male mammals of functionally ^perfect mammary organs is, in some respects, espe- cially curious. The Monotremata have the proper milk- secreting glands with orifices, but no nipples; and as ^ese animals stand at the very base of the mam- malian series, it is probable that the progenitors of the class possessed, in like manner, the milk-secreting glands, but no nipples. This conclusion is supported hy what is known of their manner of development; Idr Professor Turner informs me, on the authority of Rulliker and Langer, that in the embryo the mammary glands can be distinctly traced before the nipples are m the least visible ; and it should be borne in mind that the development of successive parts in the individual generally seems to represent and accord with the deve- lopment of successive beiugs in the same line of descent. .1 he Marsupials differ from the Monotremata by possess- lng nipples; so that these organs wore probably first Required by the Marsupials after they had diverged lr°m, and risen above, the Monotremata, and were ^cn transmitted to the placental mammals. No one "Hi suppose that after the Marsupials had approxi- mately acquired their present structure, and therefore at a rather late period in the development of the mammalian series, any of its members still remained Androgynous. We seem, therefore, compelled to recur to the foregoing view, and to conclude that the nipples ’"’ere first developed in the females of some very early marsupial form, and were then, in accordance with a Common law of inheritance, transferred in a functionally miperfect condition to the males.
Nevertheless a suspicion has sometimes crossed my
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mind that long after the progenitors of the whole mammalian class had ceased to be androgynous, both sexes might have yielded milk and thus nourished their young; and in the case of the Marsupials, that both sexes might have carried their young in mar- supial sacks. This will not appear utterly incredible, if we reflect that the males of svngnathous fishes receive the eggs of the females in their abdominal pouches, hatch them, and afterwards, as some believe, nourish the young;26 — 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, keep- ing them there until the tadpoles are born ; — that cer- tain 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 suspicion first occurred to me from the mammary glands in male mammals being developed so much more perfectly than the rudiments of those other accessory reproductive parts, which are found in the one sex though proper to the other. The mammary glands and nipples, as they exist in male mammals, can indeed hardly be called rudimentary; they are simply not fully developed and not functionally active. They are sympathetically affected under the influence of certain diseases, like the same organs in the female. At birth they often secrete a few' drops of milk ; and they have
2,1 Mr. Lockwood believes (as quoted in ‘ Quart. Journal of Science.’ April, 1868, p. 269), from what he lias observed of the development of Hippocampus, that the walls of the abdominal pouch of the male in some way afford nourishment. On male Jishes hatching the ova W their mouths, see a very interesting paper by Prof. Wyman, in ■ Proc- Boston Soc. of Nat. Hist.’ Sept. 15, 1857 ; also Prof. Turner, in ‘ Journal of Anat. and Phys.’ Nov. 1, 1806, p. 78. Dr. Gunther has likewise described similar cases.
Chap. VI. AFFINITIES AND GENEALOGY. 211
been known occasionally in man and other mammals to become well developed, and to yield a fair supply of JlJdk. Now if we suppose that during a former pro- longed period male mammals aided the females in nursing their offspring, and that afterwards from some Cause, as from a smaller number of young being pro- duced, the males ceased giving this aid, disuse of the organs during maturity would lead to their becoming tractive; and from two well-known principles of in- heritance this state of inactivity would probably be transmitted to the males at the corresponding age of Maturity. But at all earlier ages these organs would he left unaffected, so that they would be equally well developed in the young of both sexes.
Conclusion. — The best definition of advancement or pr°gress in the organic scale ever given, is that by ' °u Baer; and this rests on the amount of differ- entiation and specialisation of the several parts of same being, when arrived, as I should bo inclined 0 add, at maturity. Now as organisms have become alowly adapted by means of natural selection for diversified lines of life, their parts will have become, from the advantage gained by the division of physio- iogical labour, more and more differentiated and spe- cialised for various functions. The same part appears °ften to have been modified first for one purpose, and t]len long afterwards for some other and quite distinct Purpose ; and thus all the parts are rendered more and ^ore complex. But each organism will still retain the general type of structure of the progenitor from which ll:' was aboriginally derived. In accordance with this 'lew it seems, if we turn to geological evidence, that Olganisation on the whole has advanced throughout the " 01ld by slow and interrupted steps. In the great
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THE DESCENT OP MAN.
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kingdom of the Vertebrata it has culminated in man. It must not, however, he supposed that groups of organic beings are always supplanted and disappear as soon as they have given birth to other and more perfect groups. The latter, though victorious over their predecessors, may not have become better adapted for all places in the economy of nature. Some old forms appear to have survived from inhabiting protected sites, where they have not been exposed to very severe competition ; and these often aid us in constructing our genealogies, by giving us a fair idea of former and lost populations. But we must not fall into the error of looking at the existing members of any lowly-organised group as per- fect representatives of their ancient predecessors.
The most ancient progenitors in the kingdom of the Vertebrata, at which we are able to obtain an obscure glance, apparently consisted of a group of marine animals,21 resembling the larvae of existing Ascidians. These animals probably gave rise to a group of fishes, as lowly organised as the lancelet ; and from these the Ganoids, and other fishes like the Lepidosiren, must have been developed. From such fish a very small advance would
27 All vital functions tend to run tlieir course in fixed and recurrent periods, and with tidal animals the periods would probably be lunar ; for such animals must have been left dry or covered deep with water,— ■ supplied with copious food or stinted,— during endless generations, at regular lunar intervals. If then the Vertebrata arc descended from »» animal allied to the existing tidal Ascidians, the mysterious fact, that with tile higher and now terrestrial Vertebrata, not to mention other classes, many normal and abnormal vital prooeBseH run tlieir course according to lunar periods, is rendered intelligible. A recurrent period, if approximately of the right duration, when once gained, would not, os far as we can judge, be liable to he changed ; consequently it might be thus transmitted during almost any number of generations. This conclusion, if it could be proved sound, would be curious ; for we should then see that the period of gestation in each mammal, and the hatching of each bird’s eggs, and many other vital processes, still betrayed the primordial birthplace of these animals.
Chap. vi.
AFFINITIES AND GENEALOGY.
213
carry us on to the amphibians. We have seen that blrds and reptiles were once intimately connected togetlier ; and the Monotremata now, in a slight degree, c°nnect mammals with reptiles. But no one can at Present say by what line of descent the three higher and related classes, namely, mammals, birds, and rep- t'lcg, were derived from either of the two lower verte- orate classes, namely amphibians and fishes. In the c'lass of mammals the steps are not difficult to con- oeive which led from the ancient Monotremata to ^e ancient Marsupials; and from these to the early progenitors of the placental mammals. We may thus ^oend to the Lemuridee ; and the interval is not wide 10111 these to the Simiadae. The Simiadse then branched into two great stems, the New World and Old World ^°nkeys ; and from the latter, at a remote period, Man, 10 wonder and glory of the Universe, proceeded, j J-hus we have given to man a pedigree of prodigious eilgth, but not, it may be said, of noble quality. The |'°rld, it has often been remarked, appears as if it had °ng been preparing for the advent of man ; and this, in ?rie sense is strictly true, for he owes his birth to a long Jlle of progenitors. If any single link in this chain ad never existed, man would not have been exactly hat he now is. Unless we wilfully close our eyes, we ltlay, with our present knowledge, approximately re- °°guise our parentage ; nor need we feel ashamed of it. Je most humble organism is something much higher aa the inorganic dust under our feet ; and no one ^th an unbiassed mind can study any living creature, °Wever humble, without being struck with enthusiasm lts Marvellous structure and properties.
214
THE DESCENT OF MAN.
Part I.
CHAPTEE VII:
On the Eaces of Man.
The nature and value of specific characters — Application to the races of man — Arguments in favour of, and opposed to, ranking the so-called races of man as distinct species — Sub-species — Mono- genista and polygenisfs — 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 ex- tinction of races — The formation of races — Tlio effects of cross- ing — Slight influence of the direct action of the conditions of life — Slight or no influence of natural selection — Sexual selection.
It is not my intention here to describe the several so-called races of men; but to inquire wliat is the value of the differences between them under a classi- ficatory point of view, and how they have originated. In determining whether two or more allied forms ought to he ranked as species or varieties, natu- ralists 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 ; hut more especially whether they are constant. Constancy of character is what is chiefly valued and sought for by naturalists. Whenever it can be shewn, or rendered probable, that the forms in question have remained distinct for a long period, this becomes an argument of much weight in favour of treating them as species. Even a slight degree ot sterility between any two forms when first crossed, or in their offspring, is generally considered as a decisive
Chap, VII.
THE RACES OP MAN.
215
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 s°me repugnance to mutual pairing.
Independently of blending from intercrossing, the complete absence, in a well-investigated region, of varieties linking together any two closely-allied forms, is probably the most important of all the criterions 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 |s often unconsciously and sometimes consciously brought into play ; so that forms living in two widely separated areas, iu which most of the other inhabitants are speci- fically distinct, are themsel ves usually looked at as dis- f uict ; but in truth this affords no aid iu distinguishing geographical races from so-called good or true species. Now let us apply these generally-admitted principles the races of man, viewing him in the same spirit as a naturalist would, any other animal. Iu regard to the a> count of difference between the races, we must make 8°nie allowance for our nice powers of discrimination gained by the long habit of observing ourselves. In India, as Elphinstone remarks,1 although a newly-arrived N'lropean cannot at first distinguish the various native laces, yet they soon appear to him extremely dissimilar ; ail(i the Hindoo cannot at first perceive any difference ''tween the several European nations. Even the most distinct races of man, with the exception of certain llegro tribes, are much more like each other in form
, 1 1 History of India,’ 1841, vol. i. p. 323. Father Ripa makes exactly 16 same remark with respect to the Chinese.
216
THE DESCENT OF MAN.
Taut l
than would at first be supposed. Tin’s is well shewn by the French photographs in the Collection Anthropolo- gique du Museum of the men belonging to various races, the greater number of which, as many persons to whom I have shown them have remarked, might pass for Europeans. Nevertheless, these men if seen alive would undoubtedly appear very distinct, so that we are clearly much influenced in our judgment by the mere colour of the skin and hair, by slight differ- ences 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,2 the capa- city of the lungs, the form and capacity of the skull, and even in the convolutions of the brain.3 But it would be an endless task to specify the numerous points of structural difference. The races differ also in con- stitution, in acclimatisation, and in liability to certain diseases. Their mental characteristics are likewise very distinct ; chiefly as it would appear in their emotional, but partly in their intellectual, faculties. Every one who has had the opportunity of comparison, must have been struck with the contrast between the taciturn, even morose, aborigines of S. America and the light- hearted, talkative negroes. There is a nearly similar contrast between the Malays and the Papuans,4 who live
2 Avast number of measurements of Whites, Blacks, and Indians, are given in the ‘ Investigations in the Military and Antkiopolog. Statistics of American Soldiers,’ by B. A. Gould, I8G9, p. 298-358; on the capacity of the lungs, p. 471. Sec also the numerous ami valuable tables, by Dr. Weisbach, from the observations of Dr. Sclierzer and Dr. Schwarz, in the ' Reise der Novara : Autliropolog. Tlieil,’ 18G7.
3 Sec, for instance, Mr. Marshall’s account of the bruin of a Bush- woman, in ‘Phil, Transact.’ J8G4, p. 519.
1 Wallace, 1 The Malay Archipelago,’ vol. ii, 18G9, p. 17S.
Chap. VII.
THE RACES OF MAN.
217
Under the same physical conditions, and are separated from each other only by a narrow space of sea.
We will first consider the arguments which may be advanced in favour of classing the races of man as distinct species, and then those on the other side. If a naturalist, who had never before seen such beings, were to compare a Negro, Hottentot, Australian, or Mongolian, ho would at once perceive that they differed in a multi- tude of characters, some of slight and some of consider- able importance. On inquiry he would find that they Were adapted to live under widely different climates, and that they differed somewhat in bodily constitution and niental 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 Rood species as many to which he had been in the babit of affixing specific names. This conclusion would be greatly strengthened as soon as he had ascertained that these forms had all retained the same character for many centuries ; and that negroes, apparently identical with existing negroes, had lived at least 4000 years ago.5 He would also hear from an excellent observer,
5 With respect to the figures in the famous Egyptian caves of Ahou- Simbel, M. Pouehet says (* The Plurality of the Human Races,’ Eng. U'anslat. 1SG1, p. 50), that he was far from finding recognisable repre- sentations of the dozen or more nations which some authors believe that they can recognise. Even some of the most strongly-marked Woes cannot bo identified with that degree of unanimity which might have been expected from what lias been written on the subject. Thus Messrs. Nott and Gliddou (‘Types of Mankind,' p. 148) state that Raineses II., or the Great, has features superbly European; where- a* Knox, another firm believer in the specific distinction of the races of man (‘Races of Man,’ 1850, p. 201), speaking of young Mcmnon (the same person with Humeses 11., as 1 am iniurmed_by Mr. Birch) in- sists in tlio strongest manner that ho is identical in character with the ■frws of Antwerp? Again, whilst looking in the British Museum with two competent judges, officers of the establishment, at the statue of Kinunoph HI., we agreed that ho had a strongly negro cast of features ;
218
THE DESCENT OF MAN.
Part I.
Dr. Lund,6 that the human skulls found in the caves of Brazil, entombed with many extinct mammals, belonged to the same type as that now prevailing throughout the American Continent.
Our naturalist would then perhaps turn to geogra- phical distribution, and he would probably declare that forms differing not only in appearance, but fitted for the hottest and dampest or driest countries, as well as for the arctic regions, must be distinct species. He might appeal to the fact that no one species in the group next to man, namely the Quadrumana, can resist a low temperature or any considerable change of climate ; and that those species which come nearest to man have never been reared to maturity, even under the temperate climate ot Europe. He would be deeply impressed with the fact, first noticed by Agassiz,7 that the different races of man are distributed over the world in the same zoological provinces, as those inhabited by undoubtedly distinct species and geneva of mammals. This is mani- festly the case with the Australian, Mongolian, and Aegio races ot man ; in a less well-marked manner with the Hottentots ; but plainly with the Papuans aud Malays, who are separated, as Mr. Wallace has shewn, by nearly the same line which divides the great Malayan and Australian zoological provinces. The aborigines of America range throughout the Continent; anefthis 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
but Messrs. Nott and Gliddon (ibid. p. 146, fig. 53) describe him as u a hybrid, but not of negro intermixture”
As quoted by Nott and Gliddon, ‘ T}rpes of Mankind/ 1854, p. 439. They give also corroborative evidence ; but C. Vogt thinks that the subject requires further investigation.
1 U Diversity of Origin of the Human Races,” in the ‘ Christian Examiner,’ July, 1850.
Chap. vil.
THE RACES OF MAN.
219
opossum, range from the one into the other, as did formerly some of the gigantic Edentata. The Esqui- maux, like other Arctic animals, extend round the whole polar regions. It should he observed that the mammalian forms which inhabit the several zoological provinces, do not differ from each other in the same degree; so that it can hardly be considered as an miomaly that the Negro differs more, and the American much less, from the other races oi man than do the mammals of the same continents from those 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 varieties ot the same hind of domestic animal should be ranked as specifically distinct, that is, whether any of them are descended from distinct wild species, every naturalist would lay much stress on the fact, if established, of their external parasites being specifically distinct. All the more stress would be iaid on this fact, as it would be an exceptional one, for i am informed by Mr. Denny that the most different hinds of dogs, fowls, and pigeons, in England, are infested hy the same species of Pediculi or lice. Now Mr. A. Murray has carefully examined the Pediculi collected in different countries from the different races oi man ; 8 ai,d he finds that they differ, not only in colour, but M the structure of their claws and limbs. In every case in which numerous specimens were obtained the differences were constant. The surgeon ol a whaling 8hip 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
8 ‘Transact. It. Soc. of Edinburgh,’ vol. xxii. 1861, p. 567.
220
the descent of man.
Pakt 1.
were darker coloured and appeared different from those proper to the natives of Chiloe in South America, of winch he gave me specimens. These, again, appeared larger and much softer than European lice. Mr. Murray- procured four kinds from Africa, namely from the egioes of the Eastern and Western coasts, from the Hottentots and Caffres; two kinds from the natives of Australia; two from North, and two from South America.^ In these latter cases it may be presumed tnat the Pediculi came from natives inhabiting different districts. With insects slight structural differences, if constant, are generally esteemed of specific value : and tlie 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 distinct species.
Our supposed naturalist having proceeded thus far m his investigation, would next inquire whether the races of men, when crossed, were in any degree sterile.
e might consult the work 9 of a cautious and philo- sophical observer. Professor Broca ; and in this he would ni good evidence that some races were quite fertile together ; but evidence of an opposite nature in regard to other races. Thus it has been asserted that the native women of Australia and Tasmania rarely produce children to European men ; the evidence, however, on this head has now been shewn to be almost valueless.
he half-castes are killed by the pure blacks ; and an account has lately been published of eleven half-caste youths murdered and burnt at the same time, whose remains were found by the police.10 Again, it has often
translat* 18H PhenomoDa of Hybridity in the Genus Homo,’ Eng.
10 See the interesting letter by Mr. T. A. Murray, in the ‘ Antliro- polog. Review, April, 1808, p. liii. Iu this letter Count Strzelecki’s
UlIAP. VII.
THE RACES OF MAN.
221
been said that when mulattoes intermarry they produce few children; on the other hand, Dr. Bachman of Charlestown 11 positively asserts that he has known Mulatto families which have intermarried for several generations, and have continued on an average as fertile as either pure whites or pure blacks. Inquiries formerly 'nade by Sir C. Lyell on this subject led him, as he informs me, to tire same conclusion. In the United States the census for the year 1 S54 included, according t° Dr. Bachman, 405,751 mulattoes ; and this number, e°Hsidering all the circumstances of the case, seems Stt>all ; but it may partly be accounted for by the de- graded and anomalous position of the class, and by the profligacy of the women. A certain amount of absorp- u°n of mulattoes into negroes must always be in pro- gress ; and this would lead to an apparent diminution °f the former. The inferior vitality of mulattoes is spoken of in a trustworthy work12 as a well-known Phenomenon ; but this is a different consideration from heir lessened fertility ; and can hardly be advanced as a proof of the specific distinctness of the parent races.
doubt both animal and vegetable hybrids, when produced from extremely distinct species, are liable to Premature death ; but the parents of mulattoes cannot ( 3 put under the category of extremely distinct species. Die common Mule, so notorious for long life and vigour, and yet, r0 sterile, shews how little necessary connection
’* 0nient, that Australian women who have borne children to a white are afterwards sterile with their own race, is disproved. M. A. de J'tuatrefageg has also collected (‘ Revue des Cours Scientifiques,’ March, “■ P- 23!)) much evidence that Australians and Europeans are not eiile when crossed.
of ' An Examination of Prof. Agassiz’s Sketch of the Nat. Provinces 12, Animai World,’ Charleston, 1855, p. 44. n . * Military and Anthropolog. Statistics of American Soldiers.’ bv
A. Gould, 18G9, p. 3J9.
222
THE DESCENT OE MAN.
Part I-
there is in hybrids between lessened fertility and vitality: other analogous eases could be added.
Even if it should hereafter be proved that all the races of men were perfectly fertile together, he who was inclined from other reasons to rank them as distinct species, might with justice argue that fertility and sterility are not safe criterions of specific distinctness. We know that these qualities are easily affected by changed conditions of life or by close inter-breeding, and that they are governed by highly complex laws, for instance that of the unequal fertility of reciprocal 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 quite fertile. The degrees of sterility do not coincide strictly with the degrees of difference in external structure or habits of life. Man in many respects may be compared with those animals which have long been domesticated, and a large body of evidence can he advanced in favour of the Pallasian doctrine 13 that domestication tends to eliminate the
13 1 The Varintion of Animals and Plants under Domestication,’ vol. u- p. 109. I may here remind the reader that the sterility of species when crossed is not a specially-acquired quality; but, like the inca- pacity ot certain trees to he grafted together, is incidental on other acquired differences. The nature of these differences is unknown, but they relate more especially to the reproductive system, and much le?13 to external structure or to ordinary differences in constitution. One important element in the sterility of crossed species apparently lies iu one or both having been long habituated to fixed conditions; for w*' know that changed conditions have a special influence on the repro- ductive system, and wo have good reason to believe (us before re- marked) that the fluctuating conditions of domestication tend to elimi- nate that sterility which is so general with species in a natural stale when crossed. It lias elsewhere been shewn by mo (ibid. vol. ii. p- and ‘ Origin of Species,’ 5th edit. p. 317) that the sterility of crossed species has not been acquired through natural selection : we can see that when two forms have already been rendered very sterile, it is scarcely
Chap. yij.
THE RACES OP MAN.
223
sterility which is so general a result of the crossing of species in a state of nature. From these several con- siderations, it may be justly urged that the perfect ferti- lity of the intercrossed races of man, if established, Vv'°uld not absolutely preclude us from ranking them as distinct species.
Independently of fertility, the character of the off- spring from a cross has sometimes been thought to anord evidence whether the parent-forms ought to be j'anked as species or varieties ; but after carefully study- the evidence, I have come to the conclusion that no Seneral rules of this kind can be trusted. Thus with mankind the offspring of distinct races resemble in all r®8pects the offsj wing of true species and of varieties, ^ds is shewn, for instance, by the manner in which characters of both parents are blended, and by one form absorbing another through repeated crosses.
11 this latter case the progeny both of crossed species and varieties retain for a long period a tendency to yevert to their ancestors, especially to that one which ls prepotent in transmission. When any character has Suddenly appeared in a race or species as the result of a
t)°ssi'ble that their sterility should be augmented by the preservation or ?Urvival of the more and more slerile individuals; for as the sterility greases fewer and fewer offspring will be produced from which to . reed,and at last only single individuals will be produced, at tire rarest Q..ei vitls. But there is even a higher grade of sterility than this. Both ^ ar frier and Ivdlreuter have proved that in genera of plants including ^ Onerous species, a series can be formed from species which when s|°S3ed ybdd fewer and fewer seeds, to species which never produce a t ,n=le seed, but yot are affected by the pollen of the other species, for G german swells, It is here manifestly impossible to select the more ti^r*k individuals, which have already ceased to yield seeds; so that „ ? acme of sterility, when the ganiicn alone is affected, cannot be Mined through selection. This acme, and no doubt the other grades in are the incidental results of certain unknown differences
c Jle constitution of the reproductive system of the species which are
224
THE DESCENT OF MAN.
Pabt t
single act of variation, as is general with monstrosities,14 and this race is crossed with another not thus charac- terised, the characters in question do not commonly appear in a blended condition in the young, but are transmitted to them either perfectly developed or not at all. As with the crossed races of man cases of this kind rarely or never occur, this may be used as an argument against the view suggested by some ethnologists, namely that certain characters, for instance the blackness of the negro, first appeared as a sudden variation or sport. Had this occurred, it is probable that mulattoes would often have been born, either completely black or com- pletely white.
We have now seen that a naturalist might feel him- self 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, re- mained nearly constant for very long periods of time. He 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, in accordance 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 enquire whether the forms of man kept distinct like ordinary species, when mingled to-
14 ‘ The Variation of Animals,’ &c., vol. ii. p. 92.
Chap. VII.
THE EACES OF MAN.
225
pettier in large numbers in the same country, be would ^mediately 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, lie would behold the "'hole population consisting of Indians and Spaniards tended in various degrees.13 In many parts of the same continent he would meet with the most complex erosses between Negroes, Indians, and Europeans ; and such triple crosses afford the severest test, judging from the vegetable kingdom, of the mutual fertility of the Parent-forms. In one island of the Pacific he would hud a small population of mingled Polynesian and ■^uglish blood ; and in the Viti Archipelago a popula- tion of Polynesians and Negritos crossed in all degrees, ^lany analogous cases could he added, for instance, in ®°uth Africa. Hence the races of man are not sufifi- Oently distinct to co-exist without fusion ; and this it Js> which in all ordinary cases affords the usual test of specific distinctness.
Phir naturalist would likewise be much disturbed as s°°n as he perceived that tbe distinctive characters of eVery race of man were highly variable. This strikes every one when be first beholds the negro-slaves in Brazil, who have been imported from all parts of Africa. Bhe same remark holds good with the Polynesians, and "ith many other races. It may he doubted whether auy character can be named which is distinctive of a 1,lCe and is constant. Savages, even within the limits of le same tribe, are not nearly so uniform in character, as has often been said. Hottentot women offer certain
de Quutrefages lias given (‘ Anthropolog. Review,’ Jan. I860, P an interesting account of the success and energy of the Paulistas a 1 who are a much crossed race of Portuguese and Indians, with
auxture of the blood of other races.
VOL. I.
Q
226
THE DESCENT OE MAN.
Part I-
peculiarities, more strongly marked than those occur- ring in any other race, but these are known not to he of constant occurrence. In the several American tribes, colour and hairyness differ considerably ; as does colour to a certain degree, and the shape of the features greatly, in the Negroes of Africa. The shape of the skull varies much in some races ; 16 and so it is with every other character. Now all naturalists have learnt by dearly-bought experience, how rash it is to attempt to define species by the aid of inconstant characters.
But the most weighty of all the arguments against treating the races of man as distinct species, is that they 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 organic being, and yet there is the greatest possible diversity amongst capable judges whether he should be classed as a single species or race, or as two (Yirey), as three (.Jacquinot), as four (Kant), five (Blumenbach), six (Buffon), seven (Hunter), eight (Agassiz), eleven (Pickering), fifteen (Bory St, Yiucent), sixteen (Des- moulins), twenty-two (Morton), sixty (Crawfurd), or as sixty-three, according to Burke.17 This diversity of judgment does not prove that the races ought not to be ranked as species, but it shews that they graduate into each other, and that it is hardly possible to discover clear distinctive characters between them.
Every naturalist who has had the misfortune to under-
16 For instance with the aborigines of America and Australia. Prof- Huxley says (‘ Transact. Internat. Congress of Prehist. Arch.’ 1808, P- 105) that the skulls of many South Germans and Swiss are “as short “ and as broad as those of the Tartars,” &c.
17 Soe a good discussion on this subject in Waitz, 1 Introduct. to Anthropology,’ Eng. translat. 1863, p. "l98-208, 227. I have taken some of the above statements from Id. Tuttle’s ‘Origin and Antiquity of Physical Man,’ Boston, 1866, p. 35.
chap. yil.
THE RACES OF MAH.
227
take the description of a group of highly varying organisms, has encountered cases (I speak after ex- perience) precisely like that of man ; and if of a cautious disposition, ho will end by uniting all the forms which graduate into each other as 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 111 the Order which includes man, namely in certain genera of monkeys ; whilst in other genera, as in Cerco- Pithecus, 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 fo°uth America, and those forms which at present ap- Pear to be specifically distinct, were found to graduate mto each other by close steps, they would be ranked by ^ost naturalists as mere varieties or races ; and thus the greater number of naturalists have acted with respect to the races of man. Nevertheless it must be confessed ^at there are forms, at least in the vegetable king- dom,18 which we cannot avoid naming as species, but which are connected together, independently of inter- crossing, by numberless gradations.
Some naturalists have lately employed the term ‘sub-species” to designate forms which possess many of the characteristics of true species, but which hardly de- Serve so high a rank. Now if we reflect on the weighty arguinents, above given, for raising the races of man to t!'e dignity of species, and the insuperable difficulties 0,1 the other side in defining them, the term “ sub-
i p Prof. Jiageli lias carefully described several striking cases in his utailisclic Mittheilungen,’ B. ii. 1SGG, s. 294-369. Prof. Asa Gray w made analogous remarks on some intermediate forms in the Com- P'mtaeofK. America.
Q 2
228
THE DESCENT OF MAN.
Paf.t I.
species ” might here be used with much propriety. But from long habit the term “race” will perhaps always be employed. The choice of terms is only so far im- portant as it is highly desirable to use, as far as that may be possible, the same terms for the same degrees of difference. Unfortunately this is rarely possible; for within the same family the larger genera generally include closely-allied forms, which can be distinguished only with much difficulty, whilst the smaller genera include forms that are perfectly distinct ; yet all must equally be ranked as species. So again the species within the same large genus by no means resemble each other to the same degree : on the contrary, in most cases some of them can be arranged in little groups round other species, like satellites round planets.19
The question whether mankind consists of one or seveial species has of late years been much agitated by anthropologists, who are divided into two schools of monog'enists and polygenists. Those who do not admit the principle of evolution, must look at species either as separate creations or as in some manner distinct entitles ; and they must decide what forms to rank as species by the analogy of other organic beings which are commonly thus received. But it is a hopeless en- deavour to decide this point on sound grounds, until some definition of the term “ species ” is generally ac- cepted ; and the definition must not include an element which cannot possibly be ascertained, such as an act of creation. We might as well attempt without any defi- nition to decide whether a certain number of houses should be called a village, or town, or city. We have a practical illustration of the difficulty in the never-
‘ Origin of Species,’ 5th edit. p. G8.
C'HAP. vil. THE RACES OP MAH. 229
ending doubts whether many closely-allied mammals, ^irds, insects, and plants, which represent each other in ■^orth America and Europe, should be ranked species °r geographical races ; and so it is with the productions °f many islands situated at some little distance from the Nearest continent.
Those naturalists, on the other hand, who admit the Principle of evolution, and this is now admitted by the greater number of rising men, will feel no doubt that all the races of man are descended from a single primi- tive stock; whether or not they think fit to designate them as distinct species, for the sake of expressing their amoimt of difference.20 With our domestic animals the question whether the various races have arisen from °ne or more species is different. Although all such races, as well as all the natural species within the same genus, have undoubtedly sprung from the same primi- tive stock, yet it is a fit subject for discussion, whether, 0r instance, all the domestic races of the dog have Squired their present differences since some one species "’as first domesticated and bred by man ; or whether they °w° some of their characters to inheritance from distinct species, which had already been modified in a state of Mature. With mankind no such question can arise, for cannot be said to have been domesticated at any Particular period.
When the races of man diverged at an extremely inuiote epoch from their common progenitor, they will have differed but little from each other, and been few ’u number; consequently they will then, as far as their distinguishing characters are concerned, have had' less claim to rank as distinct species, than the existing so-
° ®ee Prof. Huxley to this effect in the ‘ Fortnightly Eeview,’ 1865 P- 275. *
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THE DESCENT OF MAN.
Part I-
called races. Nevertheless such early races would per- haps have been ranked by some naturalists as distinct species, so arbitrary is the term, if their differences, although extremely slight, had been more constant than at present, and had not graduated into each other.
It is, however, possible, though far from probable, that the early progenitors of man might at first have diverged much in character, until they became more unlike each other than are any existing races ; but that subsequently, as suggested by Vogt,21 they converged in character. When man selects for the same object the offspring of two distinct species, he sometimes induces, as far as general appearance is concerned, a considerable amount of convergence. This is the case, as shewn by Von Nathusius," with the improved breeds of pigs, which are descended from two distinct species ; and in a less well-marked manner with the improved breeds of cattle. A great anatomist, Gratiolet, maintains that the anthropomorphous apes do not form a natural sub-group ; hut 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 resemblances. I*
51 ‘ Lectures on Mau,’ Eng, translat. 1864, p. 468.
2-’ ‘Die Itacon des Schweines,’ I860, s. 46. ‘Vorstudien fur Ge- schichte, &c„ Schweineschadcl,’ 1864, s. 104. With respect to cattle, see M. de Quatrefages, ‘ Unite' de l’Espcoe liumaine,’ 1861, p. 119.
CiUp. VII.
THE RACES OF MAN.
231
'?ould be extremely rash in most cases to attribute to convergence close similarity in many points of struc- lore in beings which had once been widely different.
form of a crystal is determined solely by the Molecular forces, and it is not surprising that dissimilar ^stances should sometimes assume the same form ; c^t with organic beings we should bear in mind that ^le form of each depends on an infinitude of complex Nations, namely on the variations which have arisen, these being due to causes far too intricate to be followed °Ut, — on the nature of the variations which have been Preserved, and this depends on the surrounding physical c'°nditions, and in a still higher degree on the sur- r°unding organisms with which each has come into '''’’“petition, — and lastly, on inheritance (in itself a Uctuating element) from innumerable progenitors, all 0 which have had their forms determined through ^finally complex relations. It appears utterly incredible ,lat two organisms, if differing in a marked manner, hould ever afterwards converge so closely as to lead 0 a near approach to identity throughout their whole °j‘ganisation. In the case of the convergent races of pigs )°ve referred to, evidence of their descent from two pri- ?Aive stocks is still plainly retained, according to Yon utliusius, in certain bones of their skulls. If the races ’nan were descended, as supposed by some naturalists, °ta two or more distinct species, which had differed as ^tach, or nearly as much, from each other, as the orang ’Hers from the gorilla, it can hardly be doubted that Marked differences in the structure of certain bones would 8tlH have been discoverable in man as he now exists.
Although the existing races of man differ in many ^spects, as in colour, hair, shape of skull, proportions the body, &c., yet if their whole organisation be taken
232
THE DESCENT OF MAN.
Pakt i.
into consideration they are found to resemble each other closely in a multitude of points. Many of these points are oi so unimportant or of so singular a nature, that it is extremely improbable that they should have been independently acquired by aboriginally distinct species or races. The same remark holds good with equal or greater force with respect to the numerous points of mental similarity between the most distinct races ol man. The American aborigines, Negroes and Europeans differ as much from each other in mind as any three races that can be named ; yet I was incessantly struck, whilst living with the Fuegians on hoard the “ Beagle, with the many little traits of character, shewing how similar their minds were to ours ; and so it was with a full-blooded negro with whom I happened once to he intimate.
He who will carefully read Mr. Tylor’s and Sir J. Lubbock’s interesting works 23 can hardly fail to be deeply impressed with the close similarity between tlm men ot all races in tastes, dispositions and habits. This is shewn by the pleasure which they all take in dancing, rude music, acting, painting, tattooing, and otherwise decorating themselves, — in their mutual comprehension of gesture-language — and, as I shall be able to shew in a future essay, by the same expression in their features, and by the same inarticulate cries, when they are excited by various emotions. This similarity, or rather identity, is striking, when contrasted with the different expressions which may be observed in distinct species of monkeys. There is good evi- dence that the art of shooting with bows and arrows has not been handed down from any common progenitor of
Tylor s ‘ Early History of Mankind,’ 1865 ; for the evidence rvith respect to gesture-language, see p. 54. Lubbock’s 1 Prehistoric Times,’ 2nd edit. 1869.
Chap. VII.
THE RACES OF MAX.
233
Mankind, yet the stone arrow-heads, brought from the niost distant parts of the world and manufactured at the most remote periods, are, as Nilsson has shewn,24 almost Mention] ; and this fact can only be accounted for by various races having similar inventive or mental powers. The same observation lias been made by archseologists 25 with respect to certain widoly-prevalent ornaments, such as zigzags, &c.; and with respect to "arious simple beliefs and customs, such as the burying of the dead under megalithic structures. I remember observing in South America,26 that there, as in so many other parts of the world, man has generally chosen the summits of lofty hills, on which to throw up piles of stones, either for the sake of recording some remarkable eVent, or tor burying his 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- mlied natural forms, they use this fact as an argument that all are descended from a common progenitor who "'as thus endowed ; and consequently (hat all should be Massed under the same species. The same argument umy be applied with much force to the races of man.
As it is improbable that the numerous and unim- portant points of resemblance between the several races °f man in bodily structure and mental faculties (I do uot here refer to similar customs) should all have been independently acquired, they must have been inherited from, progenitors who were thus characterised. We thus gain some insight into the early state of man,
24 ‘ The Primitive Inhabitants of Scandinavia,’ Eng. translat. edited -~Ar J- Lubbock, 18(18, p. 101.
Hodder M. Westropp, on Cromlechs, &c., ‘Journal of Ethno- °gical Soc.’ as given in ‘Scientific Opinion,’ June 2nd, I860, p. 3.
*6 ‘Journal of Researches : Voyage of the “ Beigle,” ’ p. 46.
234
THE DESCENT OF MAN.
Part I-
before he had spread step by step over the face of the eaith. The spreading ot man to regions widely sepa- rated by the sea, no doubt, preceded any considerable amount of divergence of character in the several races; tor otherwise we should sometimes meet with the same lace in distinct continents ; and this is never the case. Sir J. Lubbock, after comparing the arts now practised by savages in all parts of the world, specifies those which man could not have known, when he first wan- dered from his original birth-place; for if once learnt they would never have been forgotten. K He thus shews that ‘‘the spear, which is but a development of the knife-point, and the club, which is but a long hammer,
‘ are the only things left.” He admits, however, that the art of making fire probably had already been dis- covered, for it is common to all the races now existing, and was known to the ancient cave-inhabitants of Lurope. Perhaps the art of making rude canoes or rafts was likewise known; but as man existed at a re- mote epoch, when the land in many places stood at a very different level, he would have been able, without the aid of canoes, to have spread widely. Sir J. Lubbock further remarks how improbable it is that our earliest ancestors could have “counted as high as ten, consider- ing that so many races now' in existence cannot get “ beyond four.” Nevertheless, at this early period, the intellectual and social faculties of man could* hardly have been inferior in any extreme degree to those now pos- sessed 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.
iiom the fundamental differences between certain
3r ‘ Prehistoric Times,’ 1809, p. 574.
THE EACES OF MAN.
235
Ca.
AP. VII.
languages, some philologists have inferred that when ^an first became widely diffused he was not a speaking animal; but it may he suspected that languages, far less perfect than any now spoken, aided by gestures, 'night have been used, and yet have left no traces °n subsequent and more highly-developed tongues. W ithout the use of some language, however imperfect, If appears doubtful whether man s intellect could have r'sen to the standard implied by his dominant position at an early period.
Whether primeval man, when he possessed very few arts 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 l'r°m some ape-like creature to man as he now exists, h would be impossible to fix on any definite point when term “ man ” ought to be used. But this is a matter very little importance. So again it is almost a Matter of indifference whether the so-called races of 'nan are thus designated, or are ranked as species 0t sub-species ; but the latter term appears the most appropriate. Finally, we may conclude that when Ike principles of evolution are generally accepted, as tlley surely will be before long, the dispute between the Cconogenists and the polygeuists will die a silent and Unobserved death.
Bne other question ought not to be passed over "dthout notice, namely, whether, as is sometimes assumed, each sub-species or race of man has sprung l0m a single pair of progenitors. With our domestic anjmals a new race can readily be formed from a single pair possessing some new character, or even from a 8lngle individual thus characterised, by carefully match-
236
THE DESCENT OF MAN.
Part !•
ing the varying offspring ; bnt most of our races have been formed, not intentionally from a selected paib but unconsciously by the preservation of many indi- viduals 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 horses, were habitually preferred, we may feel sure that two distinct sub-breeds would, in the course of time, be produced, without any particular pairs or individuals having been separated and bred from in either country. Many races have been thus formed; and their manner of formation is closely analogous with that of natural species. We know, also, that the horses which have been brought to the Falkland Islands have become, during successive generations) smaller and weaker, whilst those which have run wild on the Pampas have acquired larger and coarser heads ; and such changes are manifestly due, not to any one pair, but to all the individuals having been subjected to the same conditions, aided, perhaps, by the principle of reversion. The new sub-breeds m none of these cases are 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 and complete extinction of many races and sub-races of man are historically known events. Humboldt saw in South America a parrot which was the sole living creature that could speak the language of a lost tribe.
^hap. vn.
THE RACES OF MAN.
237
An ''ient monuments and stone implements found in aH parts of the world, of which no tradition is pre- Served by the present inhabitants, indicate much extinction. Some small and broken tribes, remnants °f former races, still survive in isolated and gene- ra% mountainous districts. In Europe the ancient races were all, according to Schaaffhausen,28 “ lower in the scale than the rudest living savages; they must therefore have differed, to a certain extent, from any existing race. The remains described by Professor •Broca29 from Les Eyzies, though they unfortunately appear to have belonged to a single family, indicate a ra°e with a most singular combination of low or simious and high characteristics, and is “entirely different 1 horn any other race, ancient or modern, that we have “ ever heard of.” It differed, therefore, from the qua- ternary race of the caverns of Belgium.
Unfavourable physical conditions appear to have had little effect in the extinction of races.30 Man has ^°ug lived in the- extreme regions of the North, with 110 wood wherewith to make his canoes or other imple- ments, and with blubber alone for burning and giving din warmth, but more especially for melting the snow. 11 the Southern extremity of America the Euegians without the protection of clothes, or of any Building worthy to he called a hovel. In South Africa ^Be aborigines wander over the most arid plains, where dangerous beasts abound. Man can withstand the deadly influence of the Terai at the toot ot the Hima- aya, and the pestilential shores of tropical Africa.
f Translation in ‘Anthropological Review, Oet. 1868, p. 431.
_ J ‘Transact. Internat. Congress of Prehistoric Arch. 1868, p. 172- ,'5- See also Broca (translation) in ‘Anthropological Review,’ Oct. P. 410.
* T»r. Gerland ‘ TJeher das Autsterben dor Naturvolker,1 1868, s. 82.
238
THE DESCENT OF MAN.
Pakt I-
Extinction follows chiefly from the competition of tribe with tribe, and race with race. Various checks are always in action, as specified in a former chapter, which serve to keep down the numbers of each savage tribe, — such as periodical famines, the wandering of the parents and the consequent deaths of infants, pro- longed suckling, the stealing of women, wars, accidents, sickness, licentiousness, especially infanticide, and, perhaps, lessened fertility from less nutritious food, and many hardships. If from any cause any one of these checks is lessened, even in a slight degree, the tribe thus favoured will tend to increase; and when one of two adjoining tribes becomes more numerous and 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 is extinct.31
When civilised nations come into contact with bar- barians the struggle is short, except where a deadly cli- mate gives its aid to the native race. Of the causes which lead to the victory of civilised nations, some are plain and some very obscure. We can see that the cultivation of the land will be fatal in many ways to savages, for they cannot, or will not, change their habits. Xe'V diseases and vices are highly destructive ; and it appears that in every nation a new disease causes much death, until those who are most susceptible to its destructive influence are gradually weeded out;52 and so it may be with the evil effects from spirituous liquors, as well as with the unconquerably strong taste for them shewn by so many savages. It further appears, mysterious as is
” Gerland (ibid. s. 12) gives facts in support of this statement.
See remarks to this effect in Sir H. Holland’s ‘ Medical Notes and Reflections, ’ 1839, p. 390.
c«ap. vii. tiib races op man. 239
fact, that the first meeting of distinct and separated People generates disease.33 Mr. Sproat, who in Man- euver Island closely attended to the subject of extinc- tion, believes that changed habits of life, which always follow from the advent of Europeans, induces much ill- health. He lays, also, great stress on so trifling a cause as that the natives become “ bewildered and dull by the “ new life around them ; they lose the motives for exer- tion, and get no new ones in their place.” "i
The grade of civilisation seems a most important dement in the success of nations which come in compe- tition. A few centuries ago Europe feared the inroads °f Eastern barbarians ; now, any such fear would be ridi- culous. It is a more curious fact, that savages did not formerly waste away, as Mr. Bagehot has remarked, hefore the classical nations, as they now do before Modern civilised nations; had they done so, the old 'n°i'alists would have mused over the event ; hut there ls Uo lament in any writer of that period over the perish- 111 § barbarians.36
Although the gradual decrease and final extinction °f the races of man is an obscure problem, we can see fhat it depends on many causes, differing in different Pieces and at different times. It is the same difficult Problem as that presented by the extinction of one of tl|e higher animals— of the fossil horse, for instance, 'vhich disappeared from South America, soon afterwards f° be replaced, within the same districts, by countless tr°ops of the Spanish horse. The New Zealander seems
^ I have Uce toil (‘Journal of Researches, Voyage of the “Beagle,”’ j Jo) a good many oases bearing on this subject : see also Gerland, s. 8. Poeppig speaks of tho “ breath of civilisation as poisonous
w savages.”
^ kproat, ‘ Scenes and Studies of Savage Life,’ 1868, p. 284.
1 On ®agehot, <* Physics and Politics,” ‘ Fortnightly Review,’ April 1, lb6s> p. 455.
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THE DESCENT OF MAN.
Part I-
conscious of this parallelism, for he compares his future fate with that of the native rat almost exterminated by the European rat. The difficulty, though great to our imagination, and really great if we wish to ascertain the precise causes, 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 hindered by various checks ; so that if any new check, or cause of destruction, even a slight one, be superadded, the race will surely decrease iu number ; and as it has ever}" where been observed that savages are much opposed to any change of habits, by which means injurious checks could he counterbalanced, decreasing numbers will sooner or later lead to extinction ; the- end, in most cases, being promptly determined by the inroads of increasing and conquering tribes.
On the Formation of the Races of Man.— It may be premised that when we find the same race, though broken up into distinct tribes, ranging over a great area, as over America, we may attribute their general resemblance to descent from a common stock. In some cases the crossing of races already distinct has led to the formation of new races. The singular fact that Europeans and Hindoos, who belong to the same Aryan stock and speak a language fundamentally the same, differ widely in appearance, whilst Europeans differ but little from Jews, who belong to the Semitic stock and speak quite another language, has been accounted for by Broca® through the Aryan branches having been largely crossed during their wide diffusion by various indigenous tribes. When two races in close contact
3f. .. Or Anthropology,” translation, * Anthropolog. Review,’ Ja"' 186S, p, 38.
CHAP; VII.
the races of man.
241
Cr°ss, the first result is a heterogeneous mixture : thus Mr. Hunter, in describing the Santali or hill- tribes of India, says that hundreds of imperceptible gradations may be traced “ from the black, squat tribes “ of the mountains to the tall olive-coloured Brahman,
“ 'Hth his intellectual brow, calm eyes, and high but “ Harrow head ; ” so that it is necessary in courts of justice to ask the witnesses whether they are Santalis °r Hindoos.37 Whether a heterogeneous people, such as the inhabitants of some of the Polynesian islands, formed by the crossing of two distinct races, with few 0r no pure members left, would ever become homo- 8eneous, is not known from direct evidence. But as "ith our domesticated animals, a crossed breed can Cei'tainly, in the course of a few generations, be fixed aud made uniform by careful selection,38 we may infer ^at the free and prolonged intercrossing during many generations of a heterogeneous mixture would supply the place of selection, and overcome any tendency to reversion, so that a crossed race would ultimately be- c°nie homogeneous, though it might not partake in an UfiUal degree of the characters of the two parent-races.
Of all the differences between the races of man, the c°loiu- of the skin is the most conspicuous and one of the best marked. Differences of this kind, it was for- tVlerly thought, could be accounted for by long expo- 8ure under different climates ; but Pallas first shewed that this view is not tenable, and he has been followed h)' almost all anthropologists.39 The view has been
'' ' The Armais of Rural Bengal,’ 1868, p. 134.
1 The Variation of Animals and Wants under Domestication,’ vol. “• P. 95.
39 Tallas, ‘Act. Acad. St. Fetersburgk,’ 1780, part ii. p. 69. He
as followed by Rudolphi, in his ‘Beytriige zuv Authropologie,’ 1812. pa ex«ellent summary of the evidence is given by Godron, ‘He.
Esptoe,’ 1859, vol. ii. p. 246, &c.
VOL. I,
R
242
THE DESCENT OF MAN.
Part I-
rejected chiefly because the distribution of the variously coloured races, most of whom must have long inhabited their present homes, does not coincide with correspond- ing differences of climate. Weight must also be given to such cases as that of the Dutch families, who, ilS we hear on excellent authority,40 have not undergone the least change of colour, after residing for three cen- turies in South Africa. The uniform appearance in various parts of the world of gypsies and Jews, though the uniformity of the latter has been somewhat exag'ge' rated,41 is likewise an argument on the same side. very damp or a very dry atmosphere has been supposed to be more influential in modifying the colour of the skin than mere heat ; but as D'Orbigny in South America, and Livingstone in Afiica, arrived at diame- trically opposite conclusions with respect to dampness and dryness, any conclusion on this head must be com sidered as very doubtful.44
Various facts, which I have elsewhere given, prove that the colour of the skin and hair is sometimes corre- lated in a surprising manner with a complete immunity from the action of certain vegetable poisons and iron1 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 individual5 escaping during a long series of generations iron1 the deadly influence of the miasmas of their native countries.
I aiterwards found that the same idea had long aS°
4(1 Sir Andrew Smith, as quoted by Knox, ‘ Paces of Man,’ p.473.
41 See De Quatrefages on this bead, ‘ Revue des Cours Scicnti£<llieB’ Oct. 17, 18G8, p. 731.
4- Livingstone’s 1 Travels and Researches in S. Africa,’ 1857, p- ^ ’ 329. D’Orbigny, as quoted by Godron, * De l’Espcce,’ vol. ii. P-
ciUp. VII.
THE RACES OF MAN.
243
°ccurred to Dr. Wells.43 That negroes, and even mulat- tos, are almost completely exempt from the yellow- *6Ver, which is so destructive in tropical America, has *0|ig been known.44 They likewise escape to a large extent the fatal intermittent fevers that prevail along, at least, 2600 miles of the shores of Africa, and which annually cause one-fifth of the white settlers to die, and Mother fifth to return home invalided.45 This immu- nity in -the negro seems to be partly inherent, de- pending on some unknown peculiarity of constitution, {|nd partly the result of acclimatisation. Pouchet 4C ^ates that the negro regiments, borrowed from the Viceroy of Egypt for the Mexican war, which had been recruited near the Soudan, escaped the yellow-fever nlniogt equally well with the negroes originally brought h'onr various parts of Africa, and accustomed to the Miniate of the West Indies. That acclimatisation plays a part is shewn by the many cases in which negroes, atter having resided for some time in a colder climate, have become to a certain extent liable to tropical *6vers.47 The nature of the climate under which the "'lute races have long resided, likewise has some in- ^ hence on them; for during the fearful epidemic of yellow-fever in Demerara during 1837, Dr. Blair found ^at the death-rate of the immigrants was proportional
, . 3 See a pc per read before the Royal Soc. in ISIS, and published in k Essays in 1818. I have given an account ot Dr. Wells’ views in the historical Sketch (p. xvi) to my 1 Origin of Species.’ Various cases of - - correlated with constitutional peculiarities are given in my
•vfc
44
U'iation of Animals under Domestication,’ vol. ii. p. 227, 335.
16 See, for instance, Nott and Gliddon, * Types of Mankind,’ p. 68.
Major Tulloeb, in a paper read before the Slatistieal Society, tail 20th, 1840, and given in the ‘ Athenaeum,' 1840, p. 353.
1 The Plurality of the Human Race’ (translat.), 1864, p. 60. i - ' Quatrefages, ‘ Unite de i’Espece Humaine,’ 1861, p. 205. Waitz 3t ’'Moduct. to Anthropology,’ translat. vol. i. 1863, p. 124. Living- »ne gives analogous cases in his ‘ Travels.’
R 2
214
THE DESCENT OF MAN.
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to the latitude of the country whence they had come- With the negro the immunity, as far as it is the result of acclimatisation, implies exposure during a prodigious length of time ; for the aborigines of tropical America, who have resided there from time immemorial, are not exempt from yellow-fever; and the Kev. 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 colour of his skin is a mere conjec- ture : it may be correlated with some difference in his blood, nervous system, or other tissues. Nevertheless, from the facts above alluded to, and from some connec- tion apparently existing between complexion and a tendency to consumption, the conjecture seemed to me not improbable. Consequently I endeavoured, with but little success,48 to ascertain how far it held wood The
to
45 In the spring of J 862 I obtained permission from the Director' General of the Medical department of the Army, to transmit to the surgeons of the various regiments on foreign service a blank table, with t.lie following appended remarks, but I have received no returns- “ As several well-marked cases have been recorded with our domestic “ animals of a relation between the colour of the dermal appendage® “ and the constitution ; and it being notorious that there is some limited “degree of relation between the colour of the races of man and the “ climate inhabited by them ; the following investigation seems wort!1 “ consideration. Namely, whether there is any relation in Europeans “ between the colour of their hair, and their liability to tho diseases of “tropical countries. If the surgeons of tho several regiments, when “ stationed in unhealthy tropical districts, would be so good as first to “ count, as a standard of comparison, bow many men, in the force “ whence the sick arc drawn, have dark and light-coloured hair, and “ hair of intermediate or doubtful tints ; and if a similar account were “ kept by the same medical gentlemen, of all tho men who suffered " from malarious and yellow fevers, or from dysentery, it would soon “be apparent, after some thousand cases had been tabulated, whether “ there exists any relation between the colour of the hair and consti' “ tutional liability to tropical diseases. Perhaps no such relation would
Chap. vil.
THE EACES OF MAN.
245
^te Dr. Daniell, who had long lived on the West Coast °f Africa, told me that he did not believe in any such elation. He was himself unusually fair, and had with- stood the climate in a wonderful manner. When he first arrived as a boy on the coast, an old and expe- rienced negro chief predicted from his appearance that this would prove the case. Dr. Nicholson, of Antigua, after having attended to this subject, wrote to me that fife did not think that dark-coloured Europeans escaped tfie yellow-fever better than those that were light- ('°loured. Mr. J. M. Harris altogether denies49 that Europeans with dark hair withstand a hot climate letter than other men ; on the contrary, experience has ^ught him in making a selection of men for service °u the coast of Africa, to choose those with red hair.
far, therefore, as these slight indications serve, there Seems no foundation for the hypothesis, which has been a°cepted by several writers, that the colour of the black Taces niay have resulted from darker and darker indi- viduals having survived in greater numbers, during t^eir exposure to the fever-generating miasmas of their Native countries.
Although with our present knowledge we cannot Account for the strongly-marked differences in colour between the races of man, either through correlation "dth constitutional peculiarities, or through the direct action of climate ; yet we must not quite ignore the
(1 discovered, but the investigation is well worth making. In ease u auy positive result were obtained, it might be of some practical use u ^ selecting men for any particular service. Theoretically the result u ^v°uld be of high interest, as indicating one means by which a race inhabiting from a remote period an unhealthy tropical climate, <{^Sht have become dark-coloured by the better preservation of dark- u {dred or dark-complexioned individuals during a long succession of
generations.”
4J ‘ Anthropological Eevie'w/ Jan. 1866, p. xxi.
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THE DESCENT OF MAN.
Part I-
latter agency, for there is good reason to believe that some inherited effect is thus produced.50
We have seen in our third chapter that the condi- tions of life, such as abundant food and general comfort, affect in a direct manner the development of the bodily frame, the effects being transmitted. Through the combined influences of climate and changed habits of life, European settlers in the United States undergo, as is generally admitted, a slight but extraordinarily rapid change of appearance. There is, also, a considerable body of evidence shewing that in the Southern States the house-slaves of the third generation present a markedly different appearance from the iield-slaves.51
If, however, we look to the races of man, as distri- buted over the world, we must infer that their charac- teristic differences cannot be accounted for bv the direct action of different conditions of life, even" after exposure to them for an enormous period of time. The Esquimaux live exclusively on animal food; they are clothed in thick fur, and are exposed to intense cold and to prolonged darkness ; yet they do not differ in any extreme degree from the inhabitants of Southern China, who live entirely on vegetable food and are ex- posed almost naked to a hot, glaring climate. The un- clothed Fnegians live on the marine productions of their inhospitable shores; the Botocudos of Brazil wander
50 See, ibr instance, Qualrefages (‘ Revue des Cours Scientifiques,’ Oct. 10, 186S, p. 721) on the effects of residence in Abyssinia aod Arabia, and other analogous cases. Dr. Bolle (‘Der Mensch, sein0 Abstnmmnng,’ &c., 18(15, s. 99) states, on the authority of Khanikof> that the greater number of German families settled in Georgia, hav0 acquired in the course of two generations dark hair and eyes. Mr. D- Forbes informs me that the Quichuas in the Andes vary greatly colour, according to the position of the valleys inhabited by them.
al Harlan, ‘Medical Researches,’ p. 532. Quatrefages (‘Unite de 1’Espece Humaine,’ 1861, p. 128) has collected much evidence on this head.
Chap. vil.
THE RACES OF MAN.
247
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 Lotocudos again, as well as the other inhabitants of tl'°pical 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 ^counted for, excejjt to a quite insignificant degree, by the inherited effects of the increased or decreased use of Parts. Men who habitually live in canoes, may have their legs somewhat stunted ; those who inhabit lofty regionS have their chests enlarged ; and those who con- stantly use certain sense-organs have the cavities in which they are lodged somewhat increased in size, and their features consequently a little modified. With civilised nations, the reduced size of the jaws fiom 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 aPpearauce in comparison with savages.52 It is also Possible that increased bodily stature, with no corre- 8poncling increase in the size of the brain, may have given to some races (judging from the previously ad- duced cases of the rabbits) au elongated skull of the dolichocephalic type.
Lastly, the little-understood principle of correlation Will almost certainly have come into action, as in the case of great muscular development and strongly pro-
62 See Prof. Sckaaffkausen, translat. in ‘Anthropological Review,’ 0ch 1868. p. 429.
'248
THE DESCENT OF MAN.
Pakt L
jecting supra-orbital ridges. It is not improbable that the texture of the hair, which differs much in the d if" feieut races, may stand in some kind of correlation with the structure of the skin ; for the colour of the hair and skin are certainly correlated, as is its colour and texture with the Mandans. 53 The colour of the skin and the odour emitted by it are likewise in some rnan- nei connected. With the breeds of sheep the number of hairs within a given space and the number of the excretory pores stand in some relation to each other.54 It we may judge from the analogy of our domesticated animals, many modifications of structure in man pro- bably come under this principle of correlated growth.
We have now seen that the characteristic differences between the races of man cannot be accounted for in a satisfactory manner by the direct action of the condi- tions 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 eminently liable, may not have been preserved and augmented during a long series of generations through natural selection. But here we are at once met by the objection that beneficial variations alone can bo thus preserved; and as far as we are enabled to judge (although always liable to error on this head) not one of the external differ- ences between the races of man is of any direct or
Mr. Gatlin states (‘ N. American Indians,' 3rd edit. 1842, vof. i. P- 49) that in the whole tribe of the Mandans, about one in ten or twelve of the members of all ages and both sexes have bright silvery grey hair, which is hereditary. Now this hair is as coarse and harsh as that of a horse’s mane, whilst the hair of other colours is fine and soft.
“ On the odour of the skin, Godron, ‘Sur PEspece,’ tom. ii. p. 217. ie pores in the skin, Dr. Wilokena, ‘Die Aufgaben der landwirth- Zootecliuik, 1869, s. 7.
chap. VII.
THE EACES OF MAN.
249
sPecial service to him. The intellectual and moral 01 s«cial faculties must of course be excepted from this re- mark ; hut differences in these faculties can have had little or no influence on external characters, lhe vari- ability of all the characteristic differences between the races, before referred to, likewise indicates that these hifterenccs cannot be of much importance , for, had they been important, they would long ago have been either fixed and preserved, or eliminated. In this Aspect man resembles those forms, called by naturalists Protean or polymorphic, which have remained extiemely variable, owing, as it seems, to their variations being of an indifferent nature, and consequently to their having leaped the action of natural selection.
We have thus far been baffled in all our attempts account for the differences between the races of man , hut there remains one important agency, namely Sexual ^election, which appears to have acted as powerfully °U man, as on many other animals. I do not intend to assert that sexual selection will account lor all the differences between the races. An unexplained resi- duum is left, about which we can in our ignorance only say, that as individuals are continually born with, f°r instance, heads a littlo rounder or narrower, and With noses a little longer or shorter, such slight dif- ferences might become fixed and uniform, if the un- known agencies which induced them were to act in a more constant manner, aided by long-continued inter- crossing. Such modifications come under the provi- sional class, alluded to iu our fourth chapter, which for the want of a better term have been called spontaneous variations. Nor do I pretend that the effects ol sexual selection can be indicated with scientific precision ; but it can be shewn that it would be an inexplicable fact if man had not been modified by this agency, which has
250
THE DESCENT OF MAN.
Part I.
acted so powerfully on innumerable animals, both high and low in the scale. It can further be shewn that the differences between the races of man, as in colour, hairy- ness, form ol features, &c., are of the nature which it might, have been expected would have been acted on by sexual selection. But in order to treat this subject in a fitting manner, I have found it necessary to pass the whole animal kingdom in review ; I have therefore de- voted to it the Second Part of this work. At the close I shall return to man, and, after attempting to shew how far he has been modified through sexual selection, will give a brief summary of the chapters in this First Part.
Part II.
SEXUAL SELECTION.
Part II.— SEXUAL SELECTION.
CHAPTER VIII.
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 ot the male Variability of the male — Choice exerted by the female — Sexual compared w ith natural selection — Inheritance, at corresponding periods of life, at corresponding seasons of the year, and as limited by sex — Relations between the several forms of inheritance — Causes why one sex and the young are not modified through sexual selection — Supplement on the proportional numbers of the two sexes throughout the animal kingdom — On the limita- tion of the numbers of the two sexes through natural selection.
With animals which have their sexes separated, the ^ales necessarily diffeT from the females in their organs °f reproduction ; and these afford the primary sexual characters. But the sexes often differ in what Hunter has called secondary sexual characters, which are not Erectly connected with the act of reproduction; for ^stance, in the male possessing certain organs of sense 0r locomotion, of which the female is quite destitute, or hi having them more highly-developed, in older that he may readily find or reach her ; or again, in the male having special organs of prehension so as to hold her securely. These latter organs of infinitely diversified hinds graduate into, and in some cases can hardly be distinguished from, those which are commonly ranked as primary, such as the complex appendages at the aPex of the abdomen in male insects. Unless indeed
254
THE PRINCIPLES OF
Part II.
we confine the term “primary” to the reproductive glands, it is scarcely possible to decide, as far as the oigans of prehension are concerned, which ought to be called primary and which secondary.
Ihe female often differs from the male in having organs for the nourishment or protection of her young, as the mammary glands of mammals, and the ab- dominal sacks of the marsupials. The male, also, in some few cases differs from the female in possessing analogous organs, as the receptacles for the ova pos- sessed by the males of certain fishes, and those tem- porarily developed in certain male frogs. Female bees ba\e a special apparatus for collecting and carrying pollen, and their ovipositor is modified into a sting for the defence of their larvae and the community. In the females of many insects the ovipositor is modified in the most complex manner for the safe placing of the eggs. Numerous similar cases could bo given, but they do not here concern us. There are, however, other sexual differences quite disconnected with the primary 01 gaiis with which we are more especially concerned — such as the greater size, strength, and pugnacity of the male, his weapons of offence or means of defence against rivals, his gaudy colouring and various orna- ments, his power of song, and other such characters.
besides the foregoing primary and secondary sexual differences, the male and female sometimes differ in structures connected with different habits of life, and not at all, or only indirectly, related to the reproductive functions. I bus the females of certain flies (Culicid® and Tabitu id;o) are blood-suckers, whilst the males live on flowers and have their mouths destitute of man- dibles.1 The males alone of certain moths and of some
1 Westwood, ‘Modern Class, of Insects,’ vol. ii. 1840, p. 541. 1 11
Ciui>. yin.
SEXUAL SELECTION.
255
crustaceans (e.g. Tanais) have imperfect, closed mouths, and cannot feed. The Complemental males of certain ('h'i'ipedes live like epiphytic plants either on the female or hermaphrodite form, and are destitute of a mouth and prehensile limbs. In these cases it is the male ’"'hick has been modified and has lost certain import- ant organs, which the females and other members of the ®anie group possess. In other cases it is the female "’hick has lost such parts; for instance, the female glow- worm is destitute of wings, as are many female moths, some of which never leave their cocoons. Many female Parasitic crustaceans have lost their natatory legs. In s°me weevil-beetles (Cureulionidae) there is a great difference between the male and female in the length
the rostrum or snout ; 2 but the meaning of this anti °f many analogous differences, is not at all understood, differences of structure between the two sexes in rela- tion to different habits of life are generally confined to the lower animals ; but with some few birds the beak °t the male differs from that of the female. No doubt ‘a most, but apparently not in all these cases, the dif- ferences are indirectly connected with the propagation °f the species : thus a female which has to nourish a Altitude of ova will require more food than the male, afel consequently will require special means for procur- ing it. A male animal which lived for a very short time might, without detriment lose through disuse its 0l‘gans for procuring food ; hut he would retain his locomotive organs in a perfect state, so that he might reach the female. The female, on the other hand, foight safely lose her organs for flying, swimming,
"’Sard to the statement about Tanais, mentioned below, I am indebted t0 Tritz Muller.
2 Kirby and Spence, ‘Introduction to Entomology,’ vol. iii. 1S26, P. 309.
256
THE PRINCIPLES OF
Part It
or walking, if she gradually acquired habits which ren- dered such powers useless,
^ e are, however, here concerned only with that kind of selection, which I hare called sexual selection. This depends on the advantage which certain individuals have over other individuals of the same sex and species, in exclusive relation to reproduction. When the two sexes differ in structure in relation to different habits of life, as in the cases above mentioned, they have no doubt been modified through natural selection, accompanied, by inheritance limited to one and the same sex. So again the primary sexual organs, and those for nourish- ing or protecting the young, come under this same head ; for those individuals which generated or nourished their offspring best, would leave, extern paribus, the greatest number to inherit their superiority ; whilst those which generated or nourished their offspring badly, would leave but few to inherit their weaker powers. ' As the male has to search for the female, he requires for this purpose oigans 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. VV hen the male has found the female he sometimes absolutely requires prehensile organs to hold her ; thus Dr. Wallace informs me that the males of cer- tain moths cannot unite with the females if their tarsi or feet are broken. Ihe males of many oceanic crusta- ceans have their legs and antennas modified in an extra- ordinary manner for the prehension of the female! Imnce we may suspect that owing to these animals being washed about by the waves of the open sea, they absolutely require these organs in order to propagate theii kind, and it so their development will have bee11 the result of ordinary or natural selection.
When the two sexes follow exactly the same habits
CHAI>. VIII.
SEXUAL SELECT IOX.
257
°f life, and tlie male has more highly developed sense °r locomotive organs than the female, it may be that those in their perfected state are indispensable to the ’Hale for finding the female ; but in tl^e vast majority °f cases, they serve only to give one male an advan- tage over another, for the less well-endowed males, time were allowed them, would succeed in pair- ing with the females; and they would in all other Aspects, judging from the structure of the female, he dually well adapted for their ordinary habits of life. In such cases sexual selection must have come into notion, for the males have acquired their present struc- ture, not from being better fitted to survive in the struggle for existence, but from having gained an ad- jutage over other males, aud from having transmitted this advantage to their male offspring alone. It was the lruportance of this distinction which led me to designate this form of selection as sexual selection. So again, h the chief service rendered to the male by his pre- luensile 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 8eXual selection, that is by the advantage acquired by Cei'tain males over their rivals. But in most cases it ls scarcely possible to distinguish between the effects °f natural and sexual selection. Whole chapters could easdy he filled with details on the differences between the sexes in their sensory, locomotive, and prehensile ?rgans. As, however, these structures are not more mteresting than others adapted for the ordinary pur- poses of life, I shall almost pass them over, giving only a low instances under each class.
there are many other structures and instincts which just have been developed through sexual selection — Sllch as the weapons of offence and the means of defence vol. i.
s
258
THE PKINCIPLES OP
Part XI-
possessed by the males for fighting with and driving away their rivals — their courage and pugnacity — their ornaments of many kinds — their organs for producing vocal or instrumental music — and their glands for emitting odours; most of these latter structures serv- ing only to allure or excite the female. That these characters are the result ol sexual and not of ordinary selection is clear, as unarmed, unornamented, or un- attractive males would succeed equally well in the battle for liie and in leaving a numerous progeny, if better endowed males were not present. We may infer that this would be the case, for the females, which are unarmed and unornamented, are able to survive and procreate their kind. Secondary sexual characters of the kind just referred to, will be fully discussed in the following chapters, as they are in many respects in' teresting, but more especially as they depend on the will, choice, and rivalry of the individuals of either sex. W hen we behold twro males lighting for the possession of the female, or several male birds displaying their gorgeous plumage, and performing the strangest 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.
In the same manner as man can improve the breed of his game-cocks by the selection of those birds which are victorious in the cockpit, so it appears that the strongest and most vigorous males, or those provided with the best weapons, have prevailed under nature? and have led to the improvement of the natural breed or species. Through repeated deadly contests, a slight degree ol variability, if it led to some advantage, how- ever slight, would suffice for the work of sexual selec- tion ; and it is certain that secondary sexual characters
'Chap. VIII.
SEXUAL SELECTION.
259
are eminently variable. In the same manner as man can give beauty, according to his standard of taste, to his male poultry— can give to the Sebright bantam a new and elegant plumage, an erect and peculiar carriage- s') it appears that in a state of nature female birds, by having long selected the more attractive males, have added°to their beauty. No doubt this implies powers of discrimination and taste on the part of the female Which will at first appear extremely improbable; but I hope hereafter to shew that this is not the case.
From our ignorance on several points, the precise banner in which sexual selection acts is to a certain extent uncertain. Nevertheless if those naturalists i\ho already believe in the mutability of species, will read the following chapters, they will, I think, agree with "ie that sexual selection has played an important part hi the history of the organic world. It is certain that With almost all animals there is a struggle between the 'Dales for the possession of the female. This iact is so Notorious that it would he superfluous to give instances, hloneo the females, supposing that their mental capacity sufficed for the exertion of a choice, conld select, one out °f several males. But in numerous cases it appears as if it had been specially arranged that there should he ", struggle between many males. I bus with migratory birds, the males generally arrive before the females at their place of breeding, so that many males are ready 1° contend for each female. The bird-catchers assert that this is invariably the ease with the nightingale and blackcap, as I am informed by Mr. Jewner W eir, who confirms tbe statement with respect to the latter species.
Mr. Swaysland of Brighton, who has been in the habit, during the last forty years, of catching our migratory Mrds on their first arrival, writes to me that he has nf‘,ver known the females of any species to arrive before
260
THE PRINCIPLES OP
Part II-
their males. During one spring he shot thirty-nine males of Hay’s wagtail (Budytes Baii ) before lie saw tv single female. Mr. Gould has ascertained l>y dissection* as he informs me, that male snipes arrive in this country before the females; but this hardly concerns ns, as snipes do not breed here. In the case of fish, at the period when the salmon ascend our rivers, the males in large numbers are ready to breed before the females- So it apparently is with frogs and toads. Throughout the great class of insects the males almost always emerge from the pupal state before the other sex, so that they generally swarm for a time before any females can be seen.” The cause of this difference between the males and females in their periods of arrival and maturity is sufficiently obvious. Those males which annually first migrated into any country, or which in the spring were first, ready to breed, or were the most eager, would leave the largest number of offspring ; and these would tend to inherit similar instincts and constitutions. On the whole there can be no doubt that wnh almost all animals, in which the sexes are separate* there is a constantly recurrent struggle between the males for the possession of the females.
Our difficulty in regard to sexual selection lies i» understanding how it is that the males which conquer otner males, or those which prove the most attractive to the females, leave a greater number of offspring to inherit their superiority than the beaten and less-
3 Even with those of plants in which the sexes are separate, tho flowers are generally mature before tho female. Many hermaphrodite Plants are, as first shewn by C. li. Sprengel, dichogamous ; that is* their male and female organs are not ready at the same time, so tied they cannot bo self-fertilised. Now with such plants the pollen i*“ generally mature in the same flower before the stigma, though there are some exceptional species in which the female organs are mature- before the male.
SEXUAL SELECTION.
261
^up. vm.
'Attractive males. Unless tills result should follow, the characters which give to certain males an advantage ■°Ver others, conhl not he perfected and augmented through sexual selection. When the sexes exist in exactly equal numbers, the worst-endowerl males will ultimately find females (except where polygamy pre- vails), and leave as many offspring, equally well fitted for their general habits of life, as the best-endowed males, f rom various facts and considerations, I fornieily in- terred that with most animals, in which secondary sexual characters are well developed, the males considerably exceeded the females in number; and this does hold Rood in some few cases. 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 propor- tions of the sexes, I do not believe that any great inequality in number commonly exists. In most cases sexual selection appears to have been effective in the following manner.
Let us take any species, a bird for instance, and divide the females inhabiting a district into two equal bodies: the one consisting of the more vigorous and fitter-nourished individuals, and the other of the less vigorous and healthy. The former, there can be little doubt, would be ready to breed in the spring before the others ; and this is the opinion of Mr. Jenner W eir, who has during many years carefully attended to the habits ot birds. There can also be no doubt that the most vigorous, healthy, and best-nourished females would on an average succeed in rearing the largest number of offspring. The males, as we have seen, are generally ■ready to breed before the females ; of the males the
262
THE PRINCIPLES OE
Part lit
strongest, and with, some species the best armed, drive away the weaker males ; and the former would then unite with the more vigorous and best-nourished fe- males, as these are the first to breed. Such vigorous pairs would surely rear a larger number of offspring than the retarded females, which would be compelled, supposing the sexes to be numerically equal, to unite- with the conquered and less powerful males ; 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 a multitude of cases the males which conquer other males, do not obtain possession of the females, independently of choice on the part of the latter. The courtship of animals is by no means so simple and short an affair as might be thought. The females are most excited by, or prefer pairing with, the more ornamented males, or those which are the best songsters, or play the best antics ; but it is obviously probable, as has been actually observed in some cases, that they would at the same time prefer the more vigorous and lively males.4 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. Such early jiaiis would have the same advantage in reariug off- spring on the female side as above explained, and nearly the same advantage on the male side. And this ap- paiently has sufficed during a long course of generations to add not only to the strength and fighting-powers of
* 1 k,ave received information, hereafter to bo givou, to tliis effect With respect to poultry. Even with birds, such as pigeons, which pan tor life the female, as I hear from Mr. Jenner Weir, will desert iior mate it lie is injured or grows weak.
CUAP. VIII.
SEXUAL SELECTION.
263
the males, but likewise to their various ornaments or other attractions.
In the converse and much rarer case of the males selecting particular females, it is plain that those which Were the most vigorous and had conquered others, would have the freest choice ; and it is almost certain that they Would select vigorous as well as attractive females. Such Pairs would have an advantage in rearing offspring, more especially if the male had the power to defend the female during the pairing-season, as occurs .with some of the higher animals, or aided in providing for the young. The same principles would apply if both sexes mutually preferred and selected certain individuals of the opposite sex ; supposing that they selected not only the more attractive, but likewise the more vigorous individuals.
Numerical Proportion of the Two Sexes. — I have remarked that sexual selection would be a simple affair if the males considerably exceeded in number the females. Hence I was led to investigate, as fai- ns I could, the proportions between the two sexes of ns many animals as possible ; but the materials are scanty. ' I will here give only a brief abstract of the results, retaining the details for a supplementary dis- cussion, so as not to interfere with the course of my nrgument. Domesticated animals alone afford the opportunity of ascertaining the proportional numbers nt birth ; but no records have been specially kept for this purpose. By indirect means, however, I. have collected a considerable body of statistical data, fiom which it appears that with most of our domestic animals the sexes are nearly equal at birth. .1 hus with race-horses, 25,560 births have been recorded during twenty-one years, and the male births have been to tbe female births as 90-7 to 100. With greyhounds the
264
THE PMNCIPLES OF
Part II.
inequality is greater than with any other animal, for during twelve years, out of 0878 births, the male births have been as 1 10-1 to 100 female births. It is, however, in some degree doubtful whether it is safe to infer that the same proportional numbers would hold good under natural conditions as under domestication; for slight and unknown differences in the conditions affect to a certain extent the proportion of the sexes. Thus with mankind, the male births in England are as 104-5, m Russia ns 10841, and with the Jews of Livonia as 120 to 100 females. The proportion is also mysteriously affected by the circumstance of the births beirm legiti- mate or illegitimate.
Foi our present purpose we are concerned with the proportion of the sexes, not at birth, but at maturity and this adds another element of doubt ; for it is a well ascertained fact that with man a considerably larger proportion of males than of females die before or during birth, and during the first few years of infancy. So it almost certainly is with male lambs, and so it may be with the males of other animals. The males of some animals kill each other by fighting; or they drive each other about until they become greatly emaciated. Iliey must, also, whilst wandering about in eager search for the females, be often exposed to various dangers. With many kinds of fish the males are much smaller than the females, and they are believed often to be devoured by the latter or by other fishes. With some birds the females appear to die in larger proportion than the males: they are also liable to be destroyed on then- nests, or whilst in charge of their young. With insects the female larvm are often larger than those of the males, and would consequently be more likely to be devoured : in some eases the mature females are less active and less rapid in their movements than the males,
■Chap. VIII.
SEXUAL SELECTION.
2G5
and would not be so well able to escape from danger. Hence, with animals in a state of nature, in order to judge of the proportions of the sexes at maturity, we must rely on mere estimation ; and this, except perhaps "hen the inequality is strongly marked, is but little trustworthy. Nevertheless, as far as a judgment can he formed, we may conclude from the facts given in the supplement, that the males of some few mammals, of many birds, of some fish and insects, considerably exceed in number the females.
bhe proportion between the sexes fluctuates slightly during successive years : thus with race-horses, foi e\ery 100 females born, the males varied from 107'1 in one year to 92-6 in another year, and with greyhounds from 116-3 to 95-3. But had larger numbers been tabulated throughout a more extensive area than England, these fluctuations would probably have disappeared; and such us they are, they would hardly suffice to lead under u state of nature to the effective action of sexual selec- lion. Nevertheless with some few wild animals, the Proportions seem, as shewn in the supplement, to fluc- luate either during different seasons or in different localities in a sufficient degree to lead to such action. Hor it should be observed that any advantage gained during certain years or in certain localities by those males which were able to conquer other males, oi were the most attractive to the females, would probably be transmitted to the offspring and would not subsequently he eliminated. During the succeeding seasons, when d'orn the equality of the sexes every male was every- where able to procure a female, the stronger or more ^tractive males previously produced would still have
least as good a chance of leaving offspring as the strong or less attractive.
Polygamy.— The practice of polygamy leads to the
266
THE PRINCIPLES OF
Pari U-
same results as would follow from an actual inequality in the number of the sexes ; for if each male secures- two or more females, many males will not be able to pair; and the latter assuredly will be the weaker or less attractive individuals. Many mammals and sonic few birds are polygamous, but with animals belonging to the lower classes 1 have found no evidence of this habit. The intellectual powers of such animals are, perhaps, not sufficient to lead them to collect and guard a harem of females. That some relation exists between poly- gamy and the development of secondary sexual cha- racters, appears nearly certain; and this supports the view that a numerical preponderance of males would bo eminently favourable to the action of sexual selection- Nevertheless many animals, especially birds, which arc strictly monogamous, display strongly-marked secondary sexual characters ; whilst some few animals, which are polygamous, are not thus characterised.
We will first briefly run through the class of mam- ma s, and then turn to birds. The gorilla seems to he a polygamist, and the male differs considerably from the female ; so it is with some baboons which Jive i*1 herds containing twice as many adult females as males, n k" outh America the Mycetes caraya presents well" marked sexual differences in colour, beard, and vocal oigans, and the male generally lives with two or three wiies. the male o t the Cebus capucinus differs some- what from the female, and appears to be polygamous/ Little is known on this head with respect to most other monkeys, but some species are strictly monogamous. The ruminants are eminently polygamous, and they
i ", ^ °n a’ SilvaSe and Wyman, • Boston Journal of Nat. His*-’
n °n Cynocephalus, Brelun, ‘Illust. TMerleben,’
‘ 0n Myeetes, Itengger, ‘ Naturgcscli. : Saugethier®
von Paraguay,’ 1830, s. 14, 20. On Cebus, Brehm, ibid. s. 108.
C«AP. VIII.
SEXUAL SELECTION.
2G7
more frequently present sexual differences than almost ahy other group of mammals, especially in their weapons, tut likewise in other characters. Most deer, cattle, and sheep are polygamous ; as are most antelopes, though Some of the ' latter are monogamous. Sir Andrew Smith, in speaking of the antelopes of South Africa, SaJrs that in herds of about a dozen there was rarely more than one mature male, iho Asiatic Ant dope djri appears to he the most inordinate polygamist iu the world; for Pallas6 states that the male drives aWay all rivals, and collects a herd of about a hundred, insisting of females and kids : the female is hornless and has softer hair, but docs not otherwise differ much from the male. The horse is polygamous, but, except 'u his greater size and in the proportions ol his both , differs but little from the mare. The wild boar, in his great tusks and some other characters, presents well-
marked sexual characters ; in Europe and in India he ^uds a solitary life, except during the breeding-season ; W at this season he consorts in India with several
fmiales, as Sir W. Elliot, who has had large experience 111 observing this animal, believes : whether this holds &»od jn Europe is doubtful, but is supported by some statements. The adult male Indian elephant, like the ^°ar, passes much of his time in solitude ; but when associating with others, “it is rare to find,”, as Dr. Campbell states, “more than one male with a whole " herd of females.” The larger males expel or kill the suialler and weaker ones. The male differs from the tamale by his immense tusks and greater size, strength, and endurance ; so great is the difference in these latter
' f alias, ‘ Spicilcgia Zoolog.’ Fnsc. xii. 1777, p. 20. Sir Andrew maith, > Illustrations of the Zoology of S. Africa,’ 1849, pi. 29, on the _°htts. Owen, in his ‘Anatomy ol Vertebrates (vol. iii. 1818, p. 683) Sffes a table incidentally showing which species of Antelopes pair and lch are gregarious. ,
2(38
THE PRINCIPLES OP
Past II.
respects, that the males when caught are valued at twenty per cent, above the females/ With other pachy- dermatous animals the sexes differ very little or not at all, and they are not, as far as known, polygamists. Hardly a single species amongst the Cheiroptera and Hdentata, or in the great Orders of the Rodents and 1 nsectivora, presents well-developed secondary sexual differences ; and .1 can find no account of any species being polygamous, excepting, perhaps, the common rat, the males of which, as some rat-catchers affirm, live with several females.
The lion in South Africa, as I hear from Sir Andrew Smith, sometimes lives with a single female, but gene- ■Lilly with more than one, and, in one case, was found with as many us five females, so that he is polygamous. He is, as far us 1 can discover, the sole polygamist i» the whole group of the terrestrial Carnivora, and he alone presents well-marked sexual characters. If, hoW- em-, we turn to the marine Carnivora, the case is widely different ; for many species of seals offer, as we shall hereafter see, extraordinary sexual differences, and they are, eminently polygamous. Thus the male sea-ele- phant of the Southern Ocean, always possesses, accord- ing to 1’eron, several females, and the sea-lion of Forster is said to be surrounded by from twenty to thirty females- In tlie North, the mule sea-bear of Steller is accom- panied by even a greater number of females.
With respect to birds, many species, the sexes 0 which differ greatly from each other, are certainly monogamous. In Great Britain we see well-marked sexual differences in, for instance, the wild-duck which pairs with a single female, with the common blackbird,
' Dr. Campbell, in • Proe. Zoolog. Soc.’ 18G9. p. 13S. See also a11 interesting paper, by Lieut. Johnstone, in ‘Proe. Asiatic Soo. of BengaV May, ibuo.
Cbap. viii.
SEXUAL SELECTION.
2G9
aUd with the bullfinch which is said to pair for life. So '1 is, as I am informed by Mr. Wallace, with the Chat- terers or Cotingid® of South America, and numerous other birds. In several groups I have not been able to discover whether the species are polygamous or mono- Satnous. Lesson says that birds ot paradise, so re- markable for their sexual differences, are polygamous, Wt Mr. Wallace doubts whether he had sufficient evi- dence. Mr. Salvin informs me that he has been led to believe that humming-birds are polygamous. The !flale widow-bird, remarkable for his caudal plumes, °«rtainly seems to be a polygamist* I have been assured by Mr. Jenner Weir and by others, that three starlingS not rarely frequent the same nest ; but whether this is° a case of polygamy or polyandry has not been
Ascertained.
The Gallinace® present almost as strongly marked dxual differences as birds of paradise or humming- birds, and many of the species are, as is well known, P°lygamous ; others being strictly monogamous. AY hat a contrast is presented between the sexes of the poly- gamous peacock or pheasant, and the monogamous guinea-fowl or partridge ! Many similar cases could 1)6 given, as in the grouse tribe, in which the males the polygamous capercailzie and black-cock differ greatly fronTthe females ; whilst the sexes of the mono- Samous red grouse and ptarmigan differ very little. 'Wongst the Cursores, no great number ot species °&er strongly - marked sexual differences, except the bustards, and the great bustard ( Otis tarda), is said to
, S ‘ The II, is,’ vol. iii. 1861, v 1»3, on the Progno Widow-bird. See als° 0:1 the Vidua axillaris, ibid. vol. ii. I860, p. 211. On the. poly- ga»iy of the Capercailzie and Great Bustard, see L. Lloyd, ‘ Game Birds Sweden,’ 1807, p. 19, and 182. Montagu and Selby speak of the Ufack Grouse as polygamous and of the Red Grouse as monogamous.
270
THE PRINCIPLES OP
Pam It
be polygamous. With the Grallatores, extremely fe* species differ sexually, but the ruff ( Machetes pugnav) atiords a strong exception, and this species is believed hy Montagu to be a polygamist. Hence it appears that with birds there often exists a close relation between polygamy and the development of strongly- marked sexual differences. On asking Mr. Bartlett at the Zoological Gardens, who has had such large ex- perience with birds, whether the male tragopan (one of the Gallinaceie) was polygamous, I was struck by his answering, “ I do not know, but should think so from “ his splendid colours.”
. It; deserves notice that the instinct of pairing with a single female is easily lost under domestication. Tim wild-duck is strictly monogamous, the domestic-duck highly polygamous. The Rev. W. 1). Fox informs me that with some half-tamed wild-ducks, kept on a large pond m his neighbourhood, so many mallards were slm* by the gamekeeper that only one was left for overt seven or eight females; yet unusually large broods were reared. The guinea-fowl is strictly monogamous ; but Mr. Fox finds that his birds succeed best when he keeps one cock to two or three hens.9 Canary-birds pair in a state of nature, but the breeders in England successfully put one male to four or five females ; never- theless the first female, as Mr. Fox has been assured, is alone treated as the wife, she and her young ones being fed by him ; the others are treated as concubines- I have noticed these cases, as it renders it in some degiee probable that monogamous species, in a state of nature, might readily become either temporarily or per- manently polygamous.
tv, if • ™7o E‘ S' ,Dl,xon’ however, speaks positively (‘ Ornamental Poultiy, ISIS, p. iG) about the eggs of the guinea-fowl being infertile vhen more than one female is kept with the same male
^hap. vm.
SEXUAL SELECTION.
271
With respect to reptiles and fishes, too little is known of their habits to enable us to speak of their marriage arrangements. The stickle-back Gasterosteus), however, is said to be a polygamist ; 10 and the male during the breeding-season differs conspicuously from the female.
To sum up on the means through which, as far as ''re can judge, sexual selection has led to the develop- ment of secondary sexual characters. It has been shewn that the largest number of vigorous offspring will be feared from the pairing of the strongest and best-armed males, which have conquered other males, with the most vigorous and best-nourished females, which are the first to breed in the spring. Such females, if they select the more attractive, and at the same time vigorous, males, will rear a larger number of offspring than the retarded females, which must pair with the less vigorous and less attractive males. So it will be ff the more vigorous males select the more attractive mnl at the same time healthy and vigorous females ; a-Hd this will especially hold good if the male defends tho female, and aids in providing food for the young. 'I’he advantage thus gained by the more vigorous pairs l11 rearing a larger number of offspring has apparently sufficed to render sexual selection efficient. But a large Preponderance in number of the males over the females ^offid be still more efficient ; whether the preponder- Ui i co was only occasional and local, or permanent ; whether it occurred at birth, or subsequently from the greater destruction of the females ; or whether it in- directly followed from the practice of polygamy.
r 27 ie Male generally more modified than the Female. — throughout the animal kingdom, when the sexes differ
w Noel Humphicys, ‘ Kiver Gardens,’ 1857.
272
THE PRINCIPLES OF
Paist IT-
from each other in external appearance, it is the male which, with rare exceptions, lias been chiefly modified; for the female still remains more like the young of lie* oun species, and more like the other members of the same group. The cause of this seems to lie in the males of almost all animals having stronger passions than the females. Hence it is the males that fight together and sedulously display their charms before the females ; and those which are victorious transmit their superiority to their male offspring. Why the males do not transmit their characters to both sexes will hereafter be considered. That the males of all mammals eagerly pursue the females is notorious to every one. So it is with birds ; but many male birds do not so much pursue the female, as display their plumage, perform strange antics, and pour forth their song, in her presence. With the few fish which have been observed, the male seems much more eager than the female; and so it is with alligators, and apparently with Batrachians. Throughout the enormous class of insects, as Kirby remarks,11 “the law is, that the male- “ S^1'|H seek the female.” With spiders and crustaceans, as I hear from two great authorities, Mr. Blackwall and Mr. G. Spence Bate, the males are more active and more enatic in their habits than the females. With insects and crustaceans, when the organs of sense or locomotion are present in the one sex and absent in the other, or when, as is frequently the ease, they are more highly developed in the one than the other, it is almost invariably the male, as far as I can discover, which retains such organs, or has them most developed ; and this shews that the male Is the more active member in the courtship of the sexes.1'
11 Kirby and Spence, ‘ Introduction to Entomology,’ vol. iii.
p. 342. ’
12 0ne pwesifie Bymenopterons insect (Westwood, 1 Modern Cls»ss- ol Insects,’ vot. ii. p. ICO) forms an exception to the rule, as the nial«
SEXUAL SELECTION.
273
■'HAP. VIII.
The female, on the other hand, with the rarest excep- tion, is less eager than the male. As the illustrious Hunter18 long ago observed, she generally “requires to ‘‘be courted;” she is coy, and may often be seen en- deavouring for a long time to escape from the male. Every one who has attended to the habits of animals "’ill be able to call to mind instances of this kind, •■fudging from various facts, hereafter to be given, and Horn the results which may fairly be attributed to sexual selection, the female, though comparatively Passive, generally exerts some choice and accepts one ^ale in preference to others. Or she may accept, as "Ppearances would sometimes lead us to believe, not Hie male which is the most attractive to her, but the °He which is the least distasteful. The exertion of s°tne choice on the part of the female seems almost as general a law as the eagerness of the male.
We are naturally led to enquire why the male in so 5nany and such widely distinct classes has been ren- dered more eager than the female, so that lie searches ■°r her and plays the more active part in courtship. H would he no advantage and some loss of power if both sexes were mutually to search for each other ; hut "liy should the male almost always be the seeker ? With plants, the ovules after fertilisation have to be “nurislied for a time; lienee the pollen is necessarily brought to the female organs — being placed on the ®tigma, through the agency of insects or ol the wind,
Jlns rudimentary wings, and never quits tlio cell in wkicli it is born, "hilst the female has well-developed wings. Andouin believes that lc-‘ females arc impregnated l>v the moles width arc born in the same with them; but it is much more probable that the females visit ’‘ther celj^ and thus avoid close interbreeding. We shall hereafter ^W'et with a few exceptional eases, in various classes, in which the eniale, instead of the male, is the seeker and wooer.
4 Essays and Observations/ edited by Owen, vol. i. 1801, p. 191.
VOL. I. T
274
THE PRINCIPLES OF
Part II1-
or by tbe spontaneous movements of the stamens ; and1 with the Algae, &c., by the locomotive power of the antherozooids. With lowly-organised animals perma- nently affixed to the same spot and having their sexes separate, the male element is invariably brought to the female ; and we can see the reason why ; for the ova, even if detached before being fertilised and not requiring subsequent nourishment or protection, would be, from their larger relative size, less easily transported than the male element. Hence plants 14 and many of the lower animals are, in this respect, analogous. The males of affixed animals having been thus led to emit their fertilising element, it is natural that any of their descendants, which rose in the scale and became loco- motive, should retain the same habit, and should closely approach the female, so that the fertilising element might not run the risk of a long transit through the waters of the sea. With some few of the lower ani- mals, the females alone are fixed, and with these the males must be the seekers. With respect to forms, of which the progenitors were primordially free, it is difficult to understand why the males should inva- riably have acquired the habit of approaching the females, instead of being approached by them. But in all cases, in order that tire males should be efficient seekers, it would be necessary that they should be en- dowed with strong passions ; and the acquirement 04 such passions would naturally follow from the more eager males leaving a larger number of offspring than the less eager.
The great eagerness of the male has thus indirectly
14 Prof. Sachs Lehrbucli tier Botanik,’ 1870, s. 633) in speaking the male and female reproductive cells, remarks, “ verlialt sick die eiB0 “ bei der Vereinigung activ, ... die andere erscheint bei dor VereiB" ignng passiv.”
°HAP. VIII.
SEXUAL SELECTION.
275
i®d to tlie mueli more frequent development of secon- dary sexual characters in the male than in the female, dint the development of such characters will have been much aided, if the conclusion at which I arrived after Undying domesticated animals, can be trusted, namely, that the male is more liable to vary than the female, d am aware how difficult it is to verify a conclusion of this kind. Some slight evidence, however, can be gained V comparing the two sexes in mankind, as man has deen more carefully observed than any other animal, during the Novara Expedition 15 a vast number of mea- s,U'ements of various parts of the body in different races "’ere made, and the men were found in almost every °ase to present a greater range of variation than the "’omen; but I shall have to recur to this subject in a future chapter. Mr. J. Wood,10 who has carefully ^tended to the variation of the muscles in man, puts 111 italics the conclusion that “ the greatest number of abnormalities in each subject is found in the males.” Jde had previously remarked that “altogether in 102 subjects the varieties of redundancy were found to ,£ de half as many again as in females, contrasting " widely with the greater frequency of deficiency in “ females before described.” Professor Macalister like- wise remarks17 that variations in the muscles “are Probably more common in males than females.” Certain muscles which are not normally present in man- viud are also more frequently developed in the male tdan in the female sex, although exceptions to this rule
1,1 ‘Reise der Novara: Antbropolog. Tkeil,’ 1807, s. 216-269. The j?sults were calculated by Dr. Weisbaoh from measurements made by .! R. Sckerzcr and Schwarz. On the greater variability of the males 1 domesticated animals, see my ‘ Variation of Animals and Plants Vr domestication,’ vol. ii. 1S68, p. 75.
1? ‘Proceedings Royal Soe.’ vol. xvi. July, 1868, p. 519 and 52-1.
1 Rroc. Royal Irish Academy,’ vol. x. 18G8, p. 123.
T 2
276
THE PRINCIPLES OF
Part II-
are said to occur. Dr. Burt Wilder18 lias tabulated the cases of 152 individuals with supernumerary digits of which 8b were males, and 39, or less than half, females; the remaining 27 being of unknown sex. It should not, however, be overlooked that women would more frequently endeavour to conceal a deformity of this kind than men. Whether the large proportional number of deaths of the male offspring of man and apparently of sheep, compared with the female offspring) before, during, and shortly after birth (see supplement)) has any relation to a stronger tendency in the organs of the male to vary and thus to become abnormal iu structure or function, I will not pretend to conjecture.
In various classes of animals a few exceptional cases occur, in which the female instead of the male has acquired well pronounced secondary sexual characters, such as brighter colours, greater size, strength, or pug' nacity. With birds, as Mre shall hereafter see, there has sometimes been a complete transposition of the ordinary characters proper to each sex; the females having become the more eager in courtship, the males remaining comparatively passive, but apparently select' iug, as we may infer from the results, the more attractive females. Certain female birds have thus been rendered more highly coloured or otherwise ornamented, as well as more powerful and pugnacious than the males, these characters being transmitted to the female offspring alone.
It may be suggested that in some cases a double process of selection has been carried on; the males having selected the more attractive females, and the latter the more attractive males. This process however, though it might lead to the modification of both sexes,
18 ‘Massachusetts Medical Soc.’ vol. ii. No. o, 1808, p. 9.
CltAP. VIII.
SEXUAL SELECTIOX.
277
"’°uld not make the one sex different from the other, Unless indeed their taste for the beautiful differed ; but this is a supposition too improbable in the case of any tUlhnal, excepting man, to be worth considering. There ate, however, many animals, in which the sexes resemble each other, both being furnished with the same orna- ments, which analogy would lead us to attribute to the agency of sexual selection. In such cases it may be suggested with more plausibility, that there has been a double or mutual process of sexual selection ; the more vigorous and precocious females having selected the more attractive anil vigorous males, the latter having mjected all except the more attractive females. But h‘°m what we know of the habits of animals, this view 18 hardly probable, the male being generally eager to Pair with any female. It is more probable that the °l’naments common to both sexes were acquired by one generally the male, and then transmitted to the off- ering of both sexes. If, indeed, during a lengthened Pei'iod the males of any species were greatly to exceed the females in number, and then during another engthened period under different conditions the reverse "ere to occur, a double, but not simultaneous, process sexual selection might easily be carried on, by which the two sexes might be rendered widely different.
We stall hereafter see that many animals exist, of "hich neither sex is brilliantly coloured or provided " 'Hi special ornaments, and yet the members of both 8exes or of one alone have probably been modified dirough sexual selection. The absence of bright tints other ornaments may bo the result of variations of Hie right kind never having occurred, or of the animals themselves preferring simple colours, such as plain black Ul white. Obscure colours have often- been acquired u'ough natural selection for the sake of protection, and
278
THE PRINCIPLES OP
Part li-
the acquirement through sexual selection of conspicuous colours, may have been checked from the danger thus incurred. But in other cases the males have probably struggled together during long ages, through brute force, or by the display of their charms, or by both means combined, and yet no effect will have been pro* duced unless a larger number of offspring were left by the more successful males to inherit their superiority, than by the less successful males ; and this, as previously shown, depends on various complex contingencies.
Sexual selection acts in a less rigorous manner than natural selection. The latter produces its effects by the life or death at all ages of the more or less successful individuals. Death, indeed, not rarely ensues from the conflicts of rival males. But generally the less success- ful male merely fails to obtain a female, or obtains a retarded and less vigorous female later in the season, or, if polygamous, obtains fewer females ; so that they leave fewer, or less vigorous, or no offspring. In re- gaid to structures acquired through ordinary or natural selection, there is in most cases, as long as the condi- tions of life remain the same, a limit to the amount of advantageous modification in relation to certain special ends ; but in regard to structures adapted to make one male victorious over another, either in fighting or i» charming the female, there is no definite limit to the amount of advantageous modification ; so that as long & the proper variations arise the work of sexual selection will go on. This circumstance may partly account for the frequent and extraordinary amount of variability presented by secondary sexual characters. Nevertheless, natural selection will determine that characters of this kind shall not be acquired by the victorious malts, which would be injurious to them in any high degree, either by expending too much of their vital powers, or
'Ciur, VIII.
SEXUAL SELECTION.
279
by exposing them to any great danger. The develop- ment, however, of certain structures — of the horns, for instance, in certain stags — has been carried to a "underfill extreme; and in some instances to an ■extreme which, as far as the general conditions of life are concerned, must be slightly injurious to the male. From this fact we learn that the advantages which favoured males have derived from conquering other males in battle or courtship, and thus leaving a Numerous progeny, have been in the long run greater than those derived from rather more perfect adaptation to the external conditions of life. We shall further see, and this could never have been anticipated, that the power to charm the female has been in some few in- stances more important than the power to conquer other- males in battle.
LAWS OF INHERITANCE.
In order to understand how sexual selection has uoted, and in the course of ages has produced conspicuous faults with, many animals of many classes, it is neces- sary to bear in mind the laws of inheritance, as far as they are known. Two distinct elements are included Under the term “ inheritance,” namely the transmission -and the development of characters; but as these generally go together, the distinction is often over- looked. * We see this distinction in those characters "'hick are transmitted through the early years ot life, hut are developed only at maturity or during old age. We see the same distinction more clearly with secondary sexual characters, for these are transmitted through both sexes, though developed iu one alone. That they are present in both sexes, is manifest when two species, having strongly-marked sexual characters, ■are crossed, for each transmits the characters proper to
280
THE PRINCIPLES OP
Part II-
its own male and female sex to the hybrid offspring of either sex. The same fact is likewise manifest, when characters proper to the male are occasionally deve- loped in the female when she grows old or becomes diseased; and so conversely with the male. Again, clnu actors occasionally appear, as if transferred from the male to the female, as when, in certain breeds of the fowl, spurs regularly appear in the young and healthy females; but in truth they are simply developed in the female ; for in every breed each detail in the structure of the spur is transmitted through the female to her male offspring. In all cases of reversion, characters aie transmitted through two, three, or many generations- and are then under certain unknown favourable con- ditions developed. This important distinction between transmission and development will be easiest kept in mind by the aid of the hypothesis of pangenesis, whether or not it be accepted as true. According to this hypo- thesis, every unit or cell of the body throws off gemmules 01 undeveloped atoms, which are transmitted to the offing of both sexes, and are multiplied by self- division. I hey may remain undeveloped during the early years of life or during successive generations," their development into units or cells, like those from which they were derived, depending on their affinity for, and uuion with, other units or cells previously developed in the due order of growth.
Inheritance at Corresponding Periods of Life.— This- tendency is well established. I f a new character appears in an animal whilst young, whether it endures through- out life or lasts only for a time, it will reappear, as » general rule, at the same age and in the same manner m the offspring. If, on the other hand, a new character appears at maturity, or even during old age, it tends-
C«AP. VIII.
SEXUAL SELECTION.
281
to reappear in tire offspring at the same advanced age. When deviations from this rule occur, the transmitted characters much oftener appear before than after the corresponding a ire. As I have discussed this subject at sufficient length in another work,11’ I will here merely give two or three instances, for the sake ot recalling the subject to the reader’s mind. In several breeds of the Fowl, the chickens whilst covered with down, the young birds in their first true plumage and in their adult plum- age, differ greatly from each other, as well as from their common parent-form, the Gallus lanldm ; and these characters are faithfully transmitted by each breed to their offspring at the corresponding period of life. For instance, the chickens of spangled Hamburghs, whilst covered with down, have a few dark spots oil the head and rump, but are not longitudinally striped, as in niany other breeds ; in their first true plumage, “they “ are beautifully pencilled,” that is each feather is- transversely marked by numerous dark bars ; but in their second plumage the feathers all become spangled 0r tipped with a dark round spot.20 Hence in this breed variations have occurred and have been trans- mitted at three distinct periods of life. The Pigeon offers a more remarkable case, because the aboriginal parent- species does not undergo with advancing age any change °f plumage, excepting that at maturity the breast becomes more iridescent; yet there are breeds which do not acquire their characteristic colouis until thej
19 ‘The Variation of Animals and Plants under Domestication’ voL li- 1868, p. 75. In the la>t chapter but one, the provisional hypothesis
pangenesis, above alluded to, is fully explained.
„ :u These facts are given on the high authority of a great breeder, ®r- Teebay, in Tegetmeier’s ‘Poultry Boole,’ 1868, p. 158. On the characters of chickens of different breeds, and on the breeds of the h'geon, alluded to in the above paragraph, see ‘ Variation of Animals," &c., vol. i. p. ICO, 249 ; vol. ii. p. 77.
282
THE PEIHCIP1ES OF
Part II-
lia-'e moulted two, three, or four times ; and these modifications of plumage are regularly transmitted.
Inheritance at Corresponding Seasons of the Year- ~ ^ animals in a state of nature innumerable instances occur of characters periodically appearing at different seasons. We see this with the horns of the stiig, and with the fur of arctic animals which becomes , thick and white during the winter. Numerous birds acquire bright colours and other decorations during the breeding-season alone. I can throw but little light on this form of inheritance from facts observed under domestication. Pallas states,21 that in Siberia domestic cattle and horses periodically become lighter-coloured during the winter; and I have observed a similar marked change of colour in certain ponies in England. Although I do not know that this tendency to assume a differently coloured coat during different seasons of the year is transmitted, yet it probably is so, as all shades of colour are strongly inherited by the horse. Nor is this orm of inheritance, as limited by season, more remark- able than inheritance as limited by age or sex.
Inheritance as limited by Sex. — The equal trans- mission of characters to both sexes is the commonest form of inheritance, at least with those animals which do not present strongly-marked sexual differences, and indeed with many of these. But characters are not rarely transferred exclusively to that sex, in which they fiist appeared. Ample evidence on this head has been advanced in my work on Variation under Domestics
-1 ‘Novas species Qnadrupedmn e Glirium ordine,’ 1778 p 7 On the trausm^ion of colour by the home, sec ‘ Variation of Animals, &«• umlci Domestication, vol. i. p. 51. Also vol. ii. p. 71, for a general -discussion on Inheritance us limited by Sox.
Chap. VIII.
SEXUAL SELECTION.
283
tion ; but a few instances may here be given. There are breeds of the sheep and goat, in which the horns °f the male differ greatly in shape from those of the female; and these "differences, acquired under domes- tication, are regularly transmitted to the same sex. With tortoise-shell cats the females alone, as a general rule, are thus coloured, the males being rusty-red. With most breeds of the fowl, the characters proper to each sex are transmitted to the same sex alone, feo general is this form of transmission that it is an ano- maly when we see in certain breeds variations trans- mitted equally to both sexes. There are also certain sub-breeds of” the fowl in which the males can hardly ho distinguished from each other, whilst the females differ considerably in colour. With the pigeon the sexes of the parent-species do not differ in any external character; nevertheless in certain domesticated breeds We male is differently coloured from the female.22 The wattle in the English Carrier pigeon and the crop in the Pouter are more highly developed in the male Wan in the female; and although these characters have been gained through long-continued selection by man, We difference between the two sexes is wholly due to die form of inheritance which lias prevailed; for it has arisen, not from, hut rather in opposition to, the
wishes of the breeder. ,
Most of our domestic races have been formed by the accumulation of many slight variations ; and as some of the successive steps have been transmitted to one alone, and some to both sexes, we find m the diffe- I'ent breeds of the same species all gradations between gloat sexual dissimilarity and complete similarity. In-
22 Dr. Cliapuis, ‘Le Pigeon Voyagcnr Beige,’ 1865, p. 87. Boitard Corbie, ‘Les Pigeons de Voliere/ &c., 1824, p. 1/3.
284
THE PEINCIPLES OF
Part II-
stances have already been given with the breeds of the o'v and pigeon , and under nature analogous cases are ot frequent occurrence. With animals under domesti- cation, but whether under nature I will not venture to say, one sex may lose characters proper to it, and may t ms come to resemble to a certain extent the opposite sox; for instance, the males of some breeds of the fowl have lost their masculine plumes and hackles. On the other hand the differences between the sexes may he increased under domestication, as with merino sheep, in which the ewes have lost their horns. Again, characters piopci to one sex may suddenly appear in the other sex; as with those sub-breeds of the fowl in which the hens whilst young acquire spurs ; or, as in certain lohsh sub-breeds, in which the females, as there is reason to believe, originally acquired a crest, and sub- sequently transferred it to the males. All these cases are intelligible on the hypothesis of pangenesis; for they depend on the gemmules of certain units of the body, although present in both sexes, becoming through the influence of domestication dormant in the one sex ; 01 it naturally dormant, becoming developed.
There is one difficult question which it will be con- venient to defer to a future chapter ; namely, whether a character at first developed in loth sexes, can be ren- dered through selection limited in its development to one sex alone. . If, lor instance, a breeder observed that some of his pigeons (in which species characters arc usually transferred in an equal degree to both sexes) varied mto pale blue; could he by long-continued selection make a breed, in which the males alone should e o( this tint, whilst the females remained unchanged ?
. * here only say, that this, though perhaps not
impossible, would he extremely difficult ; for the natural result of breeding from the pale-blue males would be
C«AI>. VIII.
SEXUAL SELECTION.
285
to change his whole stock, including both sexes, into this tint. If, however, variations of the desired tint appeared, which were from the first limited in their development to the male sex, there would not he the least difficulty in making a breed characterised by the two sexes being of a different colour, as indeed has been effected with a Belgian breed, in which the males alone are streaked with black. In a similar manner, if any Variation appeared in a female pigeon, which was lrom the first sexually limited in its development, it would be easy to make a breed with the females alone thus characterised ; but if the variation was not thus originally limited, the process would be extremely difficult, per- haps impossible.
On the Relation between the period of Development of a Character and its transmission to one sex or to both sexes.
' — Why certain characters should be inherited by both sexes, and other characters by one sex alone, namely by that sex in which the character first appeared, is in most cases quite unknown. We cannot even conjecture why "ith certain sub-breeds of the pigeon, black stria), though transmitted through the female, should ho developed in the male alone, whilst every other character is equally transferred to both sexes. Why, again, with cats, the tortoise-shell colour should, with rare exceptions, be developed in the female alone. The very same cha- racters, such as deficient or supernumerary digits, colour- blindness, &e., may with mankind be inherited by the dales alone of one family, and in another family by the females alone, though in both cases transmitted through the opposite as well as the same sex.”1 Although w'e ore thus ignorant, two rules often hold good, namely
References arc given in my ‘ Variation of A-nimnls under Domes- “cation,’ vol. ii. p. 72.
280
THE PRINCIPLES OF
Pari II-
tliat variations which, first appear in either sex at a late period of life, tend to be developed in the same sex alone ; whilst variations which first appear early in life in either sex tend to be developed in both sexes. I aur? however, far from supposing that this is the sole de- termining cause. As I have not elsewhere discussed this subject, and as it has an important bearing on sexual selection, I must here enter into lengthy and somewhat intricate details.
It is in itself probable that any character appearing at an early age would tend to be inherited equally by both sexes, for the sexes do not differ much in constitu- tion, before the power of reproduction is gained. On the other hand, after this power has been gained and the sexes have come to differ in constitution, the gemmules (if I may again use the language of pangenesis) which are cast off from each varying part in the one sex would be much more likely to possess the proper affinities for uniting with the tissues of the same sex, and thus becoming developed, than with those of the opposite sex.
I was first led to infer that a relation of this kind exists, from the fact that whenever and in whatever manner the adult male has come to differ 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 crus- taceans, spiders and some few insects, namely certain orthoptera and libellulm. In all these cases the varia- tions, through the accumulation of which the male ac- quired his proper masculine characters, must have oc- curred at a somewhat late period of life ; otherwise the young males would have been similarly characterised ; and conformably with our rule, they are transmitted to
CnAr. yni.
SEXUAL SELECTION.
287
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 hi conformity with our rule during youth. Lilt there is here room for doubt, as characters are sometimes trans- ferred to the offspring at an earlier age than that at 'vhich they first appeared in the parents, so that the parents may have varied when adult, and have trans- ferred their characters to their offspring whilst young. There are, moreover, many animals, in which the two •S(-*Xes closely resemble each other, and yet both differ from their young ; and here the characters of the adults "mst have been acquired late in life ; nevertheless, these characters in apparent contradiction to our rule, aje transferred to both sexes. We must not, however, °verlook the possibility or even probability of succes- sive variations of the same nature sometimes occurring, '"ider exposure to similar conditions, simultaneously in hoth sexes at a rather late period of life ; and in this case the variations would be transferred to the offspring of hoth sexes at a corresponding late age ; and there would he no real contradiction to our rule ot the variations "’hich occur late in life being transferred exelusiv ely to fhe sox in which they first appeared, 'this latter rule 8eems to hold true more generally than the second rule, finely, that variations which occur in either sex early hi life tend to be transferred to both sexes. As it was obviously impossible even to estimate in how large a "Umber of cases throughout the animal kingdom these l)Vo propositions hold good, it occurred to me to inves- %ate some striking or crucial instances, and to rely 011 the result.
288
THE PRINCIPLES OF
Part II-
An excellent case for investigation is afforded by the Deer Family. In all the species, excepting one, the horns are developed in the male alone, though certainly transmitted through the female, and capable of occasional abnormal development in her. 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 bad arrived at maturity and had come to differ much in constitution. In all the other species of deer the horns ought to appear later in life, leading to their develop- merit 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 hud that the horns first appear at periods varying from nine months after birth in the roebuck t0 ten or twelve or even more months in the stags of the six other larger species.24 But with the reindeer the case is widely different, for as I hear from Prof. Nilsson, who kindly made special enquiries for me in Lapland, the horns appear in the young animals within four or five weeks after birth, and at the same time in both sexes. So that here we have a structure, developed nt a most unusually early age in one species of the family* and common to both sexes in this one species.
In several kinds of antelopes the males alone ai'O
" 1 I much obliged to Mr. Cupples for having made enquiries 1' 1 me iu regard to the Roebuck and Red Deer of Scotland from h1' Robertson, the experienced head-forester to the Marquis of Breadalbane- In regard to Fallow-deer, I am obliged to Mr. Eyton and others f°r information. For the Cervus alces of N. America, son ‘ Land and Water- 1868, p. 221 and 201 ; and for the C. Virginianns and strongijloceros the same continent, see J. D. Caton, in ‘ Ottawa Acad, of Nat. Sc- 186$, p. 13. For Census Eldl of Pegu, sec Lieut. Beavan, 1 Proc- Zoolog. Soc.’ 1867, p. 762.
CiIAP. VIII.
SEXUAL SELECTION.
289
Provided with horns, whilst in the greater number both 8exes have horns. With respect to the period of de- velopment, Mr. Blyth informs me that there lived at one time in the Zoological Gardens a young koodoo (- Ant . strepsiceros), in which species the males alone ctl'e horned, and the young of a closely-allied species, viz. the eland (Ant. oreas), in which both sexes are Wned. Now in strict conformity with our rule, in the y°ung male koodoo, although arrived at the age of ten Months, the horns were remarkably small considering the size ultimately attained by them: whilst in the y°ung male eland, although only three months old, the Wns were already very much larger than in the koodoo, ft is also worth notice that in the prong-horned antelope,23 111 which species the horns, though present in both SeXes, are almost rudimentary in the female, they do not aPpear until about five or six months after birth. With shoep, goats, and cattle, in which the horns are well 'Weloped in both sexes, though not quite equal in size, tlley can be felt, or even seen, at birth or soon after- wards.20 Our rule, however, fails in regard to some ^eeds of sheep, for instance merinos, in which the rams al°ne are horned ; for I cannot find on enquiry,27 that
... 5 Antilocapra Americana. Owen, ‘Anatomy of Vertebrates, vol. Ul- P- G27.
* I have been assured tbat the horns of the sheep in North Wales lu'.1 ah'avs felt, and are sometimes even an inch in length, at birth. J ltl\ cattle Youatt says (‘ Cattle,’ 1834, p. 277) that the prominence of j2 lrontal hone penetrates the cutis at hirtb, and that the horny l27er h soon formed over it.
j i am greatly indebted to Prof. Victor Carus for having made ^dairies for me, from the highest authorities, with respect to the ri'10 sheep of Saxony. On the Guinea coast ot Africa there is a ^ Of sheep in which, as with merinos, the rams alone bear horns; Vo VVinwuod Itcade informs me that in the one case observed, a tji1Jng ram born on Feb. 10th first showed boras on March 6th, so ut in this instance the development of the horns occurred at a later V°L. I. U
290
THE PEINCIPLES OP
Part li-
the horns are developed later in life in this breed than in ordinary sheep in which both sexes are horned. But with domesticated sheep the presence or absence of horns is not a firmly fixed character ; a certain proportion of the merino ewes bearing small horns, and some of the rams beiug hornless ; whilst with ordinary sheep hornless ewes are occasionally produced.
In most of the species of the splendid family of the Pheasants, the males differ conspicuously from the females, and they acquire their ornaments at a rather late period of life. The eared pheasant (Crossopi&M* auritum), however, offers a remarkable exception, for both sexes possess the fine caudal plumes, the large e»r' tufts and the crimson velvet about the head ; and I find on enquiry in the Zoological Gardens that all these characters, in accordance with our rule, appear very' early in life. The adult male can, however, be distin- guished from the adult female by one character, namely by the presence of spurs ; and conformably with our rule, these do not begin to be developed, as I am assured by Mr. Bartlett, before the age of six mouths, and eveu at this age, can hardly be distinguished in the two sexes.28 The male and female Peacock differ con-
period of life, conformably with our. rule, than in the Welch sheep, lP which botli sexes are horned.
28 In the common peacock ( Pavo cristatus ) the male alone spurs, whilst botli sexes of the Java peacock (P. mutiem) unusual case of being furnished with spurs. Henco I fully that in the latter species they would havo been developed earl than in the common peacock ; but M. llcgt of Amsterdam informs that with young birds of the previous year, belonging to both spficje~' compared on April 23rd, 1869, there was no difference in the doveW’ mont of the spurs. The spurs, however, were as yet represented merf I by slight knobs or elevations. I presume that I should have been u* formed if any difference in the rate of development had subsequen • been obseryed.
posse offer
expect c*
icr in 11 C
cbap. VIII.
SEXUAL SELECTION.
291
spicuously 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 m life, long before the other ornaments which are con- fined to the male. The wild-duck offers an analogous case, for the beautiful green speculum on the wings is common to both sexes, though duller and somewhat smaller in the female, and it is developed early in life, whilst the curled tail-feathers and other ornaments peculiar to the male are developed later.31 Between 8Uch extreme cases of close sexual resemblance and wide dissimilarity, as those of the Crossoptilou and Peacock, many intermediate ones could be given, in which the characters follow in their order of develop- ment our two rules.
As most insects emerge from their pupal state in a mature condition, it is doubtful whether the period of development determines the transference of their cha- mbers to one or both sexes. But we do not know that tfie coloured scales, for instance, in two species of but- lerflies, in one of which the sexes differ in colour, whilst m the other they are alike, are developed at the same mlative age in the cocoon. Nor do we know whether fdl the scales are simultaneously developed on the wings
22 la some other species of the Duck Family the speculum in the sexes differs in a greater degree ; but I have not been able to dis- c°ver whether its full development occurs later in life in the males of Slleh species, than in the male of the common duck, as ought to be the J*8* according to our rule. With the allied Mergus cueuUatiis we have, °Wever, a case of this kind : the two sexes differ conspicuously in j^Uerai plumage, and to a considerable degree in the speculum, which ^ Pure white in the male and greyish- white in the female. Now the 5°Uiig males at first resemble, in all respects, the female, and have a ^reyish-white speculum, hut this becomes pure white at an earlier age aii that at which the adult male acquires his other more strongly- lurked sexual differences in plumage : see Audubon, * Ornithological l0graphy,’ vol. iii. 1835, p, 243-250.
u 2
292
THE PKINCIPLES OF
Past It
of the same species of butterfly, in which certain coloured marks are confined to one sex, whilst other marks are common to both sexes. A difference of this kind in the period of development is not so improbable as it may at first appear ; for with the Orthoptera, which assume their adult state, not by a single metamorphosis, but by a succession of moults, the young males of some species at first resemble the females, and acquire their distinc- tive masculine characters only during a later moult. Strictly analogous cases occur during the successive moults of certain male crustaceans.
We have as yet only considered the transference of characters, relatively to their period of development, with species in a natural state; we will now turn to domes* ticated animals ; first touching on monstrosities and diseases. The presence of supernumerary digits, and the absence of certain phalanges, must be determined at an early embryonic period — the tendency to profuse bleeding is at least congenital, as is probably colour* blindness — yet these peculiarities, and other simil»r ones, are often limited in their transmission to one seS > so that the rule that characters which are 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 generally true as the converse proposition, namely, that characters which appear late in life in one sex are transmitted exclu* sively to the same sex. From the fact of the above abnormal peculiarities becoming attached to one seS> long before the sexual functions are active, we may infer that there must be a difference of some kiud between the sexes at an extremely early age. With respect to sexually-limited diseases, we know too little of the period at which they originate, to draw an) fair conclusion. Gout, however, seems to fall under
C«A1>. VIII.
SEXUAL SELECTION.
293
°Ur rule; for it is generally caused by intemperance after early youth, and is transmitted from the father t° his sons in a much more marked manner than to his daughters.
Iu the various domestic breeds of sheep, goats, and battle, the males differ from their respective females m the shape or development of their horns, forehead, . mane, dewlap, tail, and hump on the shoulders; and fliese peculiarities, in accordance with our rule, are not fully developed until rather late in life. With dogs, Hie sexes do not differ, except that in certain breeds, especially in the Scotch deer-hound, the male is much Wger and heavier than the female ; and as we shall see m a future chapter, the male goes on increasing in size f° an unusually late period of life, which will account, ^cording to our rule, for his increased size being trans- mitted to his male offspring alone. On the other hand, file tortoise-shell colour of the hair, which is confined f° female cats, is quite distinct at birth, and this case ^elates our rule. There is a breed of pigeons in which flic males alone are streaked with black, and the streaks Can be detected even in the nestlings ; but they become more conspicuous at each successive moult, so that this case parti v opposes and partly supports the rule. \\ itli file English Carrier and Pouter pigeon the full develop- ment of the wattle and the crop occurs rather late in fife, and these characters, conformably with our rule, m® transmitted in full perfection to the males alone, •file following cases perhaps come within the class pre- viously alluded to, iu which the two sexes have varied m the same manner at a rather late period of life, and hiive consequently transferred their new characters to f^-th sexes at a corresponding late period ; and if so, SU('h cases are not opposed to onr rule. Thus there ai'e sub-breeds of the pigeon, described by Neumeis-
294
THE PBINCIPLES OP
Part II-
ter,“° both sexes of which change colour after moulting twice or thrice, as does likewise 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 characters by one sex or by both sexes, seems generally determined by the period at which such characters are developed. Thus in all the many breeds in which the adult male differs greatly in colour from the female and from the adult male parent-species, he differs from the young male, so that the newly acquired characters must have appeared at a rather late period of life. On the other hand with most of the breeds in which the two sexes resemble each other, the young are coloured in nearly the same manner as their parents, and this renders it probable that their colours first appeared earlv 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, leading to its transference to both sexes ; for the males alone of many natural species are either black or white, the females being very differently coloured. With the so-called Cuckoo sub-breeds of the fowl, in which the feathers are transversely pencilled with dark stripes, both sexes and the chickens are coloured in nearly the same manner- The laced plumage of the Sebright bantam is the same in both sexes, and in the chickens the feathers are tipped with black, which makes a near approach to lacing- Spangled Hamburghs, however, offer a partial exception)
30 ‘Das Ganze der Tanbenzucht,’ 1837, s. 21, 24. For the case <4 the streaked pigeons, see Dr. Cliapuis, ‘Le Pigeon Vo3rageur Bel gc, X8G5, p. 87.
Chap. VIII.
SEXUAL SELECTION.
205
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. Turning to other characters besides colour : the males alone of the wild parent-species and of most domestic breeds possess a fairly well developed comb, but in the young of the Spanish fowl it is largely developed at a very early age, and apparently in consequence ot this it is of unusual size in the adult lemales. In the Game breeds pugnacity is developed at a wonderfully early age, of which curious proofs could be given ; and this character is transmitted to both sexes, so that the hens, from their extreme pugnacity, are now generally exhibited in separate pens. With the Polish breeds the bony protuberance of the skull which supports the crest is partially developed even before the chickens are hatched, and the crest itself soon begins to grow, though at first feebly ; 31 and in this breed a great bony protu- berance and an immense crest characterise the adults of both sexes.
Finally, from what we have now seen of the relation which exists in many natural species and domesticated l’aces, between the period of the development of their characters and the manner of their transmission for Example the striking fact of the early growth of the horns in the reindeer, in which both sexes have horns, >u comparison with their much later growth in the other species in which the male alone beais horns
31 For full particulars and references on all these points respecting he several breeds of the Fowl, see ‘Variation of Animals and Plants Under Domestication,’ vol. i. p. 2-50, 250. In jegaid to the higher Wiirnala, the sexual differences which have arisen under domestication ate described in the same work under the head of each species.
296
THE PBINCIPLES OF
Pari If
we may conclude that one cause, though not the sole cause, of characters being exclusively inherited bv one sex, is their development at a late age. And secondly, that one, though apparently a less efficient, cause of characters being inherited by both sexes is their deve- lopment at an early age, whilst the sexes differ but little in constitution. It appears, however, that sour© difference must exist between the sexes even during an early embryonic period, for characters developed at°this age not rarely become attached to one sex.
Summary and concluding remarks. — From the fore- going discussion on the various laws of inheritance, we learn that characters often or even generally tend to become developed in 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 laws, from unknown causes, are very liable to change. Hence the successive steps in the modification of a species might readily be transmitted in different ways; some of the steps being transmitted to one sex, and some to both ; some to the offspring at one age, and some at all ages. Not only are the laws of inherit- ance extremely complex, but so are the causes which induce and govern variability. The variations thus caused are preserved and accumulated by sexual selec- tion, which is in itself an extremely complex affair, depending, as it does, on ardour in love, courage, and the rivalry of the males, and on the powers of percep- tion, taste, and will of the female. Sexual selection will also be dominated by natural selection for the general welfare of the species. Hence the manner in which the individuals of either sex or of both sexes are affected through sexual selection cannot fail to be complex in the highest degree.
ciUp. VIII.
SEXUAL SELECTION.
297
When variations occur late in life in one sex, and are transmitted to the same sex at the same age, the other sex and the young are necessarily left unmodified. When they occur late in life, but are transmitted to koth sexes at the same age, the young alone are left un- modified. Variations, however, may occur at any period of life in one sex or in both, and be transmitted to both spXes at all ages, and then all the individuals of the species will be similarly modified. In the following chapters it will be seen that all these cases frequently °ccur under nature.
Sexual selection can never act on any animal be- fore the age for reproduction has arrived. From the great eagerness of the male it has generally acted on this sex and not on the females. The males We thus become provided with weapons for fight- Ojg with their rivals, or with organs for discovering aud securely holding the female, or for exciting and charming her. When the sexes differ in these respects, ]t is also, as we have seen, an extremely general law tl»at the adult male differs more or less from the young male; and we may conclude from this fact that the Recessive variations, by which the adult male became modified, have not generally occurred much before the for reproduction. Whenever some or many of the Variations have occurred early in liie, the young males "nil partake in a less or greater degree of the dia- meters of the adult males. Differences of this kind between the old and young males may be observed "ith many animals, for instance with birds.
It is probable that young male animals have often tended to vaiy in a manner which would not only have Wn of no use to them at an early age, but would have
men actually injurious,— as in the acquisition of bright e°lours, which would have rendered them conspicuous
298
THE PRINCIPLES OF
Part #•
to their enemies, or of structures, such as great horns, which would have expended much vital force in their development. Variations of this kind occurring in the young males will almost certainly have been eliminated through natural selection. With the adult and experienced males, on the other hand, the advan- tage derived from the acquisition of such characters, in their rivalry with other males, will often have more than counterbalanced exposure to some degree of danger.
As variations analogous to those which give to the male a superiority over other males in fighting, or in finding, securing, or charming the opposite sex, would, if they happened to arise in the female, be of no service to her, they will not have been preserved through sexual selection in this sex. We have good evidence that with domesticated animals variations of all kinds are soon lost through intercrossing and accidental deaths, it not carefully selected. Consequently, varia- tions of the above kind, if they chanced to arise h1 the female, would be extremely liable to be lost; and the females would he left unmodified, as far as these characters are concerned, excepting in so f»r as they were received through transference from the males. No doubt, if the females varied and trans- mitted their newly acquired characters to their off- spring of both sexes, the characters which were ad- vantageous to the males would be preserved through sexual selection, although they were of no use to the females themselves. In this case, both sexes would be modified in the same manner. But I shall here- after have to recur to these more intricate contin- gencies.
Variations occurring late in life, and transmitted to one sex alone, have incessantly been taken advantage
Chap. VIII.
SEXUAL SELECTION.
299
°f and accumulated through sexual selection in rela- tion to the reproduction of the species ; therefore it appears, at first sight, an unaccountable fact that simi- lar variations have not frequently been accumulated through natural selection, in relation to ordinary habits °f life. If this had occurred, the two sexes would fre- quently have been differently modified, for the sake, h>r instance, of capturing prey or of escaping from danger. "We have already seen and shall hereatter Uieet with other instances of differences of this kind between the two sexes, especially with the lower ani- mals; hut they are rare in the higher classes. We should, however, bear in mind that the sexes in the higher classes generally follow the same habits of life; and supposing that the males alone varied in a manner favouring their power of gaining subsistence, &c., and transmitted such variations to their male offspring alone, these would acquire an organization superior to that of the females ; but it is probable that the females, h'oru having the same general constitution and iroin being exposed to the same conditions, would sooner or later vary in the same manner ; and as soon as this °ccurred, the variations would he equally preserved through natural selection in the two sexes, which would thus ultimately become like each other, lhe case is widely different with variations accumulated through ^xual selection; for the habits of the two sexes in tclation to the reproductive functions are not the same, Hlld sexually-transmitted modifications serviceable to the one sex would in it be preserved, whilst similar ^edifications would often be quite useless to the other 8ex, and consequently would in this latter soon be lost.
In the following chapters, I shall treat of the secondary sexual characters in animals of all classes,
300
THE PRINCIPLES OF
Part II-
and shall endeavour in each case to apply the prim ciples explained in the present chapter. The lowest classes will detain us for a very short time, hut the higher animals, especially birds, must be treated at considerable length. It should be borne in mind that for reasons already assigned, I intend to give only a few illustrative instances of the innumerable structures by the aid of which the male finds the female, or, when iound, holds her. On the other hand, all structures and instincts by which the male conquers other males, and by which he allures or excites the female, will he billy discussed, as these are in many ways the most interesting.
Supplement on the proportional numbers of the two sexes in animals belonging to various classes.
As no one, as far as I can discover, has paid atten* tion to the relative numbers of the two sexes through' out the animal kingdom, I will here give such materials as I have been able to collect, although they are ex- tremely imperfect. They consist in only a few instances of actual enumeration, and the numbers are not very large. As the proportions are known with certainty o» a large scale in the case of man alone, I will first give them, as a standard of comparison.
Man. — Iu England during ten years (from 1857 to 1860) 707,120 children on an annual average have been born alive, in the proportion of 104-5 males to 100 females. But in 1857 the male births through- out England were as 105-2, and in 1865 as 104-0 to 100. Looking to separate districts, in Buckinghamshire (where on an average 5000 children are annually born)
C0AP. VIII.
SEXUAL SELECTION.
301
the mean proportion of male to female births, during the whole period of the above ten years, was as 102'8 to 100; whilst in N. Wales (where the average annual hirths ’are 12,873) it was as high as 106-2 to 100. 'halving a still smaller district, viz., Rutlandshire (where the annual births average only 739), in 1864 the male hirths were as 114-6, and in 1862 as 97'Q to 100; but oven in this small district the average of the 7385 hirths during the whole ten years was as 104-5 to 100; that is in the same ratio as throughout England.32 The proportions are sometimes slightly disturbed by Unknown causes; thus Prof. Faye states “that m “ some districts of Norway there has been during a “decennial period a steady deficiency of boys, whilst “in others the opposite condition has existed.” In Trance during forty-four years the male to the female hhths have been as 106-2 to 100; but during this Period it has occurred five times in one department, “Hif times in another, that the female biiths have e*ceeded the males. In Russia the average proportion is as hi'di as 108-9 to 100.33 It is a singular fact that "’ith Jews the proportion of male births is decidedly Wger than with Christians : thus in Prussia the propor- tion is as 113, in Breslau as 114, aud in Li vonia as 120 to 100 • the Christian births in these countries being hhe same as usual, for instance, in Livonia as 104 to hJO.'s It is a still more singular fact that m different Nations, under different conditions and climates, in Naples, Prussia, Westphalia, France and England, the
T 32 ‘Twenty-ninth Annual Report of the Registrar-General for 186C. ln this report, (p. xii) a special decennial table w given.
. * Tor Norway and Russia, see abstract of Rrof. Faye s researches, I? ‘British aud Foreign Medico- CUimrg. Review. April, 1807, p. 3-13, ^ For France, the ‘ Annuaire porn- l’Au 1807, p. -13.
34 In regard to the Jews, see M. Tliury, La Loi de Pr
‘ La Loi de Production des
302 THE PRINCIPLES OF Part I1'
excess of male over female births is less when they »re illegitimate than when legitimate.35
In various parts of Europe, according to Prof. F;iVe and other authors, “a still greater preponderance “ males would be met with, if death struck both sex<-s “ 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.” Moreover during the first four or five years of life more male children die than females; “ for example in England, during the first year, 12$ “ boys die for every 100 girls, — a proportion which i» “ France is still more unfavourable.”36 As a consequent of this excess in the death-rate of male children, and ot the exposure of men when adult to various dangers, and of their tendency to emigrate, the females in all old-settle^ countries, where statistical records have been kept,37 ai‘® found to preponderate considerably over the males.
It has often been supposed that the relative age® of the parents determine the sex of the offspring; and Prof. Leuckart38 has advanced what he considers
35 Babbage, 1 Edinburgh Journal of Science,’ 1S29, voL i. p. 88; als® p. 90, ou still-lmrn children. On illegitimate children in England see ‘ Report of Registrar-General for 1866,’ p. xv.
36 ‘British and Foreign Medico-Chi rurg. Review,’ April, 1867, P' 343. Dr. Stark also remarks (‘ Tenth Annual Report of Births, Death3- &c., iu Scotland,’ 1867, p. xxviii) that “ These examples may suffie8 “ to shew that, at almost every stage of life, the males iu Scotia"1*
“ have a greater liability to death and a higher death-rate than tla- “ females. The fact, however, of this peculiarity being most strong')
“ developed at that infantile period of life when the dress, food, »D‘*
“ general treatment of both sexes are alike, seems to prove that t'1*’
“ higher male death-rate is an impressed, natural, and constitution!11 “ peculiarity due to sex alone.”
37 With the savage Guaranys of Paraguay, according to the accui**® Azara (‘Voyages dans l’Ame'rique merid.’ tom. ii. 1809, p. 60, 179)' the women in proportion to the men are as 14 to 13.
3S Leuckart (in Wagner, ‘ Handwdrterhuch der Phys.’ B. iv. s. 774.
C»AP. VIII.
SEXUAL SELECTION.
303
sufficient evidence, with respect to man and certain domesticated animals, to shew that this is one impor- tant factor in the result. So again the period of impregnation has been thought to be the efficient cause ; but recent observations discountenance this belief. Again, with mankind polygamy has been supposed to lead to the birth of a greater proportion of female infants; but Dr. J. Campbell39 carefully attended to ibis subject in the harems of Siam, and lie concludes that the proportion of male to female births is the Sjtine as from monogamous unions. Hardly any animal has been rendered so highly polygamous as oui imglish hice-horses, and we shall immediately see that their male and female offspring are almost exactly equal in dumber.
Horses. — Mr. Tegetmcicr has been so kind as to tabulate for me fr°m the ‘ Racing Calendar’ the births of race-horses during a period of twenty-one years, viz. from 1846 to 1867 ; 1849 being omitted, as no returns were that year published. The total births have been 25, 660,' *“ consisting of 12,763 males and 12,797 females, or in the proportion of 99‘7 males to 100 females. As these numbers are telerably large, and as they are drawn from all parts of England, during several years, we may with much confidence conclude that Mtli 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 °ccur with mankind, when a small and thinly-populated area is con- Adored : thus in 1850 the male horses were as 107T, and m 1807 only 92'6 to 100 females. Jn the tabulated returns the propor- tions vary in cycles, for the males exceeded the females during six Successive years ; and the females exceeded the males during two
^ Anthropological Review, April, 18i0, p- cuii.
40 During the last eleven years a record has been kept of the number of *»es which have proved barren or prematurely slipped their foals; and it deserves notice, as shewing how infertile these highly-nurtured and rather 'hsely-interbred animals have become, that not far from one-third of the “‘Wes failed to produce living foals. Thus during 1866, 809 male colts 816 female colts were born, and 743 mares Exiled to produce offspring. C^i'iug 1867, 836 males and 902 females were born, and 794 mares failed.
304
THE PRINCIPLES OF
Part H-
periods each of four years : this, however, may he accidental ; least I can detect nothing of the kind with man in the decenniad table in the Registrar's Report for 1866. I may add that certain mares, and this holds good with certain cows and with women, tend to produce more of one sex than of the other ; Mr. Wright of Yeldersley House, informs mo that one of his Arab mares, though put seven times to different horses, produced seven fillies.
Dogs. — During a period of twelve years, from 1857 to 1868, tb® births of a large number of greyhounds, throughout England, have been sent to the ‘ Field ’ newspaper ; and T am again indebted to Mr. Tegetmeier for carefully tabulating the results. The recorded births have been 0878, consisting of 3605 males and 3273 female that is, in tlio proportion of HOT males to 100 females. Th® greatest fluctuations occurred in 1864, when the proportion was as 95-3 males, and in 1867, as 11 6-3 males to 100 females. The above average proportion of 110T to 100 is probably nearly correct in th® case of the greyhound, but whether it would hold with other domes- ticated breeds is in some degree doubtful. Mr. Cupples has enquired from several great breeders of dogs, and finds that all without exception believe that females are produced in excess ; he suggests that this belief may have arisen from females being less valued and the consequent disappointment producing a stronger impressiou on the mind.
>S keep, i he sexes of sheep arc not ascertained by agriculturist® until several months after birth, at the period when the males ar® castrated; so that the following returns do not give the proportion® 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 on® or two years ; therefore the proportion of males would be somewh®*' greater at birth than at the age of castration. This is a remarkabl® coincidence with what occurs, as we have seen, with mankind, and both cases probably depend on some common cause. 1 have re- ceived returns from four gentlemen in England who have bred lot®' land sheep, chiefly Lcicesters, during the last ten or sixteen year® i they amount altogether to 8965 births, consisting of 4407 mad®3 and 4558 females ; that is in the proportion of 90-7 males to 1(’,) females. With respect to Cheviot and black-faced sheep bred >n Scotland, I have received returns from six breeders, two of them a large scale, chiefly for the years 1867-1869, but some of th® returns extending hack to 1862. The total number recorded amounts to 50,685, consisting of 25,071 males and 25,614 femaleS’ or in the proportion of 97’9 males to 100 females. If we take tb® English and Scotch returns together, the total number amount®
CHAP. VIII.
SEXUAL SELECTION.
305
59,650, consisting of 29,478 males and 30,172 females, or as J7'7 to 100. So that with sheep at the age of castration the females are certainly in excess of the males ; but whether tliis would hold S«od at birth is doubtful, owing to the greater liability in the males to early death.41
Of Cattle 1 have received returns from nine gentlemen of 982 births, too few to bo trusted ; these consisted of 477 bull-calves and ®05 cow-calves ; i.e. in the proportion of 94'4 males to 100 females.
Tie Rev. W. 1). Fox informs me that in 1867 out of 34 calves born 011 a farm in Derbyshire only one was a bull. Mr. Harrison Weir ’" rites to me that he has enquired from several breeders of Figs, and taost of them estimate the male to the female births as about 7 to 6. This same gentleman has bred Babbits for many years, ahd has noticed that a far greater number of bucks are produced ^an does.
Of mammalia in a state of nature I have been able to learn very mtle. In regard to the common rat, 1 have received conflicting statenients. Mr. II. Elliot of Laighwood, informs rnc that a rat- etcher assured him that he had always found the males in Sreat excess, even with the young in the nest. In consequence this, Mr. Elliot himself subsequently examined some hundred ,1(1 ones, and found the statement true. Mr. F. Buckland has r<i<l a large number of white rats, and he also believes that the ''tales greatly exceed the females. In regard to Moles, it is said aat “ the males are much more numerous than the females ;”42 aQd as the catching of these animals is a special occupation, the statement may perhaps be trusted. Sir A. Smith, in describing antelope of S. Africa1 * * 4 ** ( Kobus ellipsiprymnus), remarks, that *" the herds of this and other species, the males are few in number ?0tupared with the females : the natives believe that they are horn this proportion ; others believe that the younger males are ex- tolled from the herds, and Sir A. Smith says, that though he has ''Vise If never seen herds consisting of young males alone, others ''uiitii that this does occur. It appears probable that the young jllales when expelled from the herd, would be likely to fall a prey 0 'he many beasts of prey of the countiy.
1 am much indebted to Mr. Cupples for having procured for me the ,, ,u'e returns from Scotland, as well as some of the following returns on
,n, , Mr. it. Elliot, of Laighwood, first called my attention to the pre- 4i! k-6 ^“tbs of the males,— a statement subsequently confirmed by Mr. ln,;biS°n and others. To this latter gentleman, and to Mr. Payan, I owe
« t?°ks for the larger returns on sheep.
,3 “ell, ‘ History of British Quadrupeds,’ p. 100.
* Illustrations of the Zoology of S. Africa,’ 1849, pi. 29.
VOL. I.
X
306
THE PRINCIPLES OF
Part II-
BIRDS.
With respect to the Fowl, I have received only one account) namely, that out of 1001 chickens of a highly-bred stock of Cochins reared during eight years by Mr. Stretch, 487 proved males and 514 females : i. e. as 94-7 to 100. In regard to domestic pigeons there is good evidence that the males are produced in excess, or that their lives are longer ; for these birds invariably pair, and single males, as Mr. Tegetmeier informs me, can always be purchased cheaper than females. Usually the two birds reared from the two egg8 laid in the same nest consist of a male and 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 a state of nature, Mr. Gould and others44 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 most numerous. Large numbers of pheasants are reared by Mr. Baker of Leadonhall from eggs laid by wild birds, and ho informs Mr. Jenner Weir that four or five males to one female are generally produced. An experienced ob- server remarks45 that in Scandinavia the broods of the capercailzie and black-cock contain more males than females ; and that with the Dal-ripa (a kind of ptarmigan) more males than females attend tbc Ms 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,48 seems clear that the males of the partridge must bo in considerable excess in the south of England ; and 1 have been assured that this is the ease in Scotland. Mr. Weir on enquiring from tho dealer8 who receive at certain seasons large numbers of ruffs (MachdtS pugnax) was told that tho males are much the most numerous- This same naturalist has also enquired for me. from the bird" catchers, who annually catch an astonishing number of various sin&d species alive for tho London market, and he was unhesitating'/ answered by an old and trustworthy man, that with the chaffinch tho males are in largo excess ; he thought as high as 2 males
44 Bi-ehm (‘ Illust. Thierleben,’ B. iv. s. 990) comes to the same c°n” elusion.
45 On the authority of L. Lloyd, ‘ Game Birds of Sweden/ 1867, P*
46 ‘ Nat. Hist, of Selbourne,’ letter xxix. edit, of 1825, vol. i. p. 139.
ClUp. VIII.
SEXUAL SELECTION.
307
b female, or at least as high as 5 to 3.47 The males of the black- bird, he likewise maiutained, were by far the most numerous, whe- ther caught by traps or by netting at night. These statements 1Tlay apparently be trusted, because the same man said that the 8eSes are about equal with the lark, the twite ( Linar ia montana ), and goldfinch. On the other hand he is certain that with the 0°mnion linnet, the females preponderate greatly, but unequally 'fining different years ; during some years he has found the females tu the males as four to one. It should, however, bo borne in mind, that the chief season for catching birds does not begin till Sept- ember, so that with some species partial migrations may havo begun, **>4 the flocks at this period often consist of hens alone. Mr. Salvin fluid particular attention to the sexes of the humming-birds in bentral America, and he is convinced that with most of the species Jbe males are in excess ; thus one year he procured 204 specimens belonging to ten species, and these consisted of 100 males and of ^ females. With two other species the females were in excess : but the proportions apparently vary either dining different seasons IJr in different localities; for on one occasion the males of Cam- tyloptcrus hemileucurus were to the females as five to two, and "b another occasion48 in exactly the reversed ratio. As bearing on ^bis latter point, 1 may add, that Mr. Powys found in Corfu and hpirus the sexes of the chaffinch keeping apart, and “the females by far the most numerous;” whilst in Palestine Mr. Tristram ((°Und “ the male flocks appearing greatly to exceed the female in dumber.”43 So again with the Quwcalus major, Mr. (1. Taylor™ that in Florida there were “ very few females in proportion to the males,” whilst in Honduras the proportion was the other way, lbe species there having the character of a polygamist.
FISH.
itli Fish the proportional numbers of the sexes can he ascertained ri,lJy by catching them in the adult or nearly adult state; and there
. [ Mr, Jenner Weir dar
received similar information, on making enquiries l'mg the following year. To shew the number of chaffinches caught, I "ay mention that in 1869 there was a match between two experts ; and man caught in a day 62, and another 40, male chaffinches. The greatest JJber ever caught by one man in a single day was 70.
'ibis,’ vol. ii. p. 260, as quoted in Gould's ‘ Trochilidse,’ 1861, p. 52. .■ r the foregoing proportions, I am indebted to Mr. Salvin for a table of , results.
49 / T, .
lo , „ !s>. *860, p. 137 ; and 1867, p. 369.
308
THE PRINCIPLES OF
Part II-
are many difficulties in arriving at any just conclusion.61 Infertile females might readily be mistaken for males, as Dr. Gunther has remarked to me in regard to trout. With some species the males are believed to die soon after fertilising the ova. Wilh 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. Carboimier,62 who has especially attended to the natural history of the pike ( Esox luciu.fi) 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 the same, cause to greater danger than the females. Nevertheless in the few cases in which the proportional numbers have been actually observed, the males appear to be largely in excess. Thus Mr. R. Buist, the superintendent of the Stonnontfield experi- ments, says that in 1865, out of 70 salmon first landed for the purpose of obtaining the ova, upwards of 60 were males. In 1867 he again “calls attention to the vast disproportion of the “males to the females. We had at the outset at least ten males “ to one female.” Afterwards sufficient females 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.”63 This disproportion, no doubt, can be accounted for in part, but whether wholly is very doubtful, by the males ascending the rivers before the females. Mr. F. Bnekland remarks in regard to trout, that “ it is a curious fact that the males prepon- “ derate very largely in number over the females. Tt invariably “ happens that, when the first rush of fish is made to the net, there “ will* be at least seven or eight males to one female found captive- “ L cannot quite account for this ; either the males are more numcr- “ ous than the females, or the latter seek safety by concealment “ rather than flight.” ne then adds, that by carefully searching the banks, sufficient females for obtaining ova can be found.54 Mr. H- Lee informs me that out of 212 trout, taken for this purpose in Lord Portsmouth’s park, 1 50 were males and 62 females.
With the Cyprinidai the males likewise seem to be in excess ; but several members of this Family, viz., the carp, tench, bream and minnow, appear regularly to follow the practice, rare in the
51 Leuckart quotes Bloch (Wagner, ‘ Handworterbnch der Phys.’ B- l' ' 1853, s. 775), that with fish there are twice as many males as females.
52 Quoted in the ‘Farmer,’ March 18, 1869, p. 369.
53 ‘The Stormontfieid Piscicultural Experiments,’ 1866, p. 23. The ‘ Field ’ newspaper, June 29th, 1867.
54 ‘ Land and Water,’ 1868, p. 41.
Uiup. VIII.
SEXUAL SELECTION.
309
'animal kingdom, of polyandry ; for the female whilst spawning is always attended by two males, one on each side, and in the case of the bream by three or four males. This fact is so well known, that it is always recommended to stock a pond with two male tenches to one female, or at least with three males to two females. With the minnow, an excellent observer states, that on the spawning- beds the males are ten times as numerous as the females '■ when a female comes amongst the males, “ she is immediately pressed closely “ by a male on each side ; and when, they have been, in that situa- tion for a time, are superseded by other two males. 05
INSECTS.
In this class, the Lepidoptera alone afford the means of judging °f the proportional numbers of the sexes; for they have been col- lected with special care by many good observers, and have been Wgely 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 ibis has ever been done. The general opinion appears to he that the sexes are nearly equal, but in Italy as 1 hear from Professor Canestrini, many breeders are convinced that the females are produced in. excess. The same naturalist, however, informs me, that in the two yearly broods of the Ailanthtis silk- moth {Hornby.i) c.ynthia), the males greatly preponderate in the first, whilst. in the second the two sexes are nearly equal, or the females rather in excess.
In regard to Butterflies in a state of nature, several observers have been much struck by the apparently enormous preponderance of the males.00 Thus Mr. Bates,67 in speaking of the species, no loss than 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 m the Senus Papilio the males to the females as four to one; and Mr.
" Tan-ell, ‘Hist. British Fishes,’ vol. i. 1836, p. 307 ; on the Cyprinus lan»o, p. 331 ; on the Tinea vulgaris, p. 331 ; on the Abramis brama, p. w*6. See, for the minnow ( Leuciscus phoxims), ‘ Loudon s Mag. of Nat.
fbrt.’ vol. v. 1832, p. 082.
33 Leuckart quotes Meinecke (Wagner, ‘ Handworterbuch der L- >v. 1853, s. 775) that with Butterflies the males are three or four as numerous as the females.
i7 ‘The Naturalist on the Amazons,’ vol. ii. 1863, p. 228, 347.
Phys.’
times
310
THE PRINCIPLES OF
Part II-
^ alsh, who informed me of this statement, says that with P- turnus this is certainly the case, in South Africa, Mr. R. Trimen found the males in excess in 19 species ;58 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 during seven years only fivo lemales. In the island of Bourbon, M. Maillard states that the males of one species of Papdlio are twenty times as numerous as the females,59 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 in number the males; but this is perhaps the case with three South African species. Mr. Wallace*0 states that the females of Omithoptera crams, in the Malay archipelago, are more common and more easily caught than the males ; but this is a rare butterfly. 1 rnay here add, that in Hyperythra, a genus of moths, Guene'e 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,61 it was generally admitted that the males of most Lepidoptera, in the adult or imago state, are caught in greater numbers than the females ; hut this lact was attributed by various observers to the more retiring habits of the females, and to the males emerging earlier irom the cocoon, This latter circumstance is well known to occur with most Lepidoptera, as well as with other insects. So that, as M. Bersonnat remarks, the males of the domesticate*- Bmbyx Yamamai, are lost at the beginning of the season, an*1 the females at the end, from the want of mates.® I cannot how- ever persuade myself that these causes suffice to explain the great excess of males in the oases, above given, of butterflies which are extremely common in their native countries. Mr. Stainton, who has paid such close attention during many years to the smaU°r moths, informs me that when lie 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 m°st
58 Four of these cases are given by Mr. Trimen in his ‘Ehopalocer8 Africa! Australis.’
a" Quoted by Trimen, * Transact. Ent. Soc.’ vol. v. part iv. 1866, p. 330' 60 ‘ Transact. Liun. Soc.’ vol. xxv. p. 37.
6a ‘Proc. Entomolog. Soc.’ Feb. 17th, 1868.
fi" Quoted by Dr. Wallace in ’Proc. Ent. Soc.’ 3rd series, vol. v. 18^’’ p. 487. ’
Chap. VIII.
SEXUAL SELECTION.
311
Numerous. Several entomologists concur in tliis view. Mr. Double- day, however, and some others, take an opposite view, and are con- Dnced that they have reared from the egg and caterpillar states a larger proportion of males than ol females.
besides the more active habits of the males, their earlier emerg- ence from the cocoon, and their frequenting in some cases more open stations, other causes may be assigned for an apparent or real difference in the proportional numbers oi the sexes ot Lepidop- iera, when captured in the imago state, and when reared from the egg or caterpillar state. It is believed by many breeders in Italy, as I hear from Professor C’anestrini, that the female caterpillar ot 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 eollsct 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 arc worth the trouble of rearing. Birds when surrounded by caterpillars would probably devour the largest ; and Professor Canestrini informs me that in Italy some brooders believe, though on insufficient evidence, that in the first brood ol the Ailanthus silk-moth, the wasps destroy a larger number of the female than of the male caterpillars. Dr. Wallace further remarks that female caterpillars, from being larger than the males, require more time for their development and consume more food anil mois- ture; and thus they would ho exposed during a longer time to danger from ichneumons, birds, &o., 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 the numbers at maturity, when the sexes arc 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 lac-t may perhaps he 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 FAachistw rufocinei ea. it is well known that if a virgin Lasiocampcc qttcrcus or S aturnia cctrpini be exposed in a cage, vast numbers ot males collect round her, and if confined in a room will even come down the chimney to her.
312
THE PRINCIPLES OF
Part B-
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 under confinement. Mr. Trimen exposed in the Isle of Wight a, box in which a female of the Lasiocampa had been confined on the previous day, and five males soon endeavoured to gain admittance. M. Verreaux, in Australia, having placed the female of a small Bombyx in a box in his pocket, was fol- lowed by a crowd of males, so that about 200 entered the house with him.®
Mr. Doubleday has called my attention to Dr. Staudinger’s84 list of Lepidoptera, which gives the prices of the males and females of 300 species or well-marked varieties of (Rkopaloeera) butterflies. Ihe prices lor both sexes of the very common species are of course the same ; hut with 114 of the rarer species they differ ; th8 males being in all cases, excepting one, the cheapest. On an ave- rage of the prices of the 113 species, the price of the male to that of the female is as 100 to 140; and this apparently indicates chat inversely the males exceed the females in number in the same proportion. About 2000 species or varieties of moths (Heterocera) are catalogued, those with wingless females being here excluded on account of the difference in habits of the two sexes : of these 2000 species, 141 differ in price according to sex, the males of 130 being cheaper, and the males ot only 11 being dearer than the females. The average price ot the males of the 130 species, to that of the females, is as 100 to 143. With respect to the butterflies in this priced list, Mr. Doubleday thinks (and no man in England has had more experience), that there is nothing in the habits of the species which can account for the difference in the prices of the two sexes, and that it can be accounted for only by an excess in the numbers of the males. But, I am bound to add that Dr. Staudingcr himself, as he informs me, is of a different opinion. He thinks that the less active habits of the lemales and the earlier emergence of the males will account for his collectors securing a larger number of males than ot females, and consequently for the lower prices of the former. With respect to specimens reared from the caterpillar- state, Dr- Staudingcr believes, as previously stated, that a greater number of females than of males die under confinement in the cocoons. He adds that with certain species one sex seems to preponderate over the other during certain years.
Oi direct observations on tko sexes of Lepidoptera, roared either
Blanchard, ‘ Metamorphoses, Moeurs des Insectes,’ 1868, p. 225-226. ‘ Lcpidopteren-Doubblettren Liste,’ Berlin, No. x. I860.
CiUp. VIII.
SEXUAL SELECTION.
313
from eggs or caterpillars, I have received only the few following
cases : —
Rev. J. Hollins 63 of Exeter reared, during 1868, . imagos of 73 species, which consisted ot *'h\ Albert Jones of Eltham reared, during 1868, im-
ages of 9 species, which consisted of
during 1869 he reared imagos from 4 species, consist-
, ing of . . . .
*'*r. Buckler of Emsworth, Hants, during 1869, reared . imagos from 74 species, consisting of . . . .
Dl'. Wallace of Colchester reared from one brood of
. Bombvx Cynthia
IJr- Wallace raised, from cocoons ofBombyx Pernyi sent
n from China, during 1869
Ur. Wallace raised, during 1868 and 1869, from two lots of cocoons of Bombyx yama-mai . . . , . .
Total
|
Males. |
Females. |
|
153 |
137 |
|
159 |
126 |
|
114 |
112 |
|
180 |
169 |
|
52 |
48 |
|
224 |
123 |
|
52 |
46 |
|
934 |
761 |
So that in these eight lots of cocoons and eggs, males were pro- ceed in excess. Taken together the proportion of males is as ■^2'7 to 100 females. But the numbers are hardly large enough 4(1 be trustworthy.
On the whole, from the above various sources of evidence, all feinting to the same direction, I infer that with most species of bepidopttra, the males in the imago state generally exceed the ett)ales in number, whatever the proportions may be at their first emergence from the egg.
With reference to the other Orders of insects, 1 have been able ,0 collect very little reliable information. With the stag-beetle facanus cervus) “ the males appear to he much more numerous ‘than the females” but when, as Cornelius remarked during 1867, Unusual number of these beetles appeared in one part of Ger- ?auy, the females appeared to exceed the nudes as six so one. With one of the Elatoricto, the males are said to he much more Numerous than the females, and “ two or three are often found
Suited with one female f* so that here polyandry seems to prevail.
This naturalist lias been so kind as to send ine some results from 'finer years, in which the females seemed to preponderate ; but so many the figures were estimates, that 1 found it impossible to tabulate them. e GUnther’s ‘Record of Zoological Literature,’ 1867, p. 260. On the pwess of female Lucanus, ibid. p. 250. On the males of Lucanus in Eng- j! Westwood, ‘ Modern Class, of Insects,’ vol. i.lp. 187. On the Siagoninm, 01cl- p. 172.
314
THE PRINCIPLES OF
Part H
With Siagonium (Staphylinidaj), in which the males are furnished with horns, “ the females are far more numerous than the opposite “ sex.” Mr. Janson stated at the Entomological Society that the females of the hark-feeding Tomicus villosus are so common as t*3 he a plague, whilst the males are so rare as to be hardly know3- In other Orders, from unknown causes, but apparently in some inf stances owing to parthenogenesis, the males of certain species have never been discovered or are excessively rare, as with several of tbc Cynipid®.67 In all the gall-making Cynipidaj known to Mr. Wahhi the females are four or five times as numerous as the males ; and it is, as he informs me, with the gall-making Cecidomyikn (Dipterft)- With some common species of Saw-flies (Tenthredina) Mr. Smith has reared hundreds of specimens from larva of all siM6' l)ut has never reared a single male : on the other hand Curtis say& that with certain species (Athalia), bred by him, the males to tl'e females were as six to one ; whilst exactly the reverse occurred wi^ the mature insects of the same species caught in the fields. Wi^ the Neuroptera, Mr. Walsh states that iu many, but by no mean9 in all, the species of the Olonatous groups (Ephemerina), there is* great overplus of males : in the genus Hctierina, also, the males ar® generally at least four times as numerous as the females. In certain species in the germs Complies the males are equally numerous whilst in two other species, the females are twice or thrice numerous as the males. In some European species of Psocus tbo®” sands of females may bo collected without a single male, whilst with other species of the same genus both sexes are common.69 I* England, Mr. Mac Lachlan has captured hundreds of the feioak Apatania muliebris, but has never seen the male; and of J3ore“s hyemalis only four or five males have been here seen.70 With mo®1 of these species (excepting, as I have heard, with the Tenthredin:1') there is no reason to suppose that the females are subject to parthr nogenesis ; and thus we sec how ignorant wc are on the causes of ^ apparent discrepancy in the proportional numbers of the two scs1*;
in the other Classes of the Articulata 1 have been able to coll1** still less information. With Spiders, Mr. Blackwall, who has cab' fully attended to this class during many years, writes to me tfc®1 the males from their more erratic habits are more commonly seeIJ’
67 Walsh, in ‘ The American Entomologist,’ vol. i. 1869, p. 103. F.
‘ Record of Zoological Literature,’ 1867, p. 328.
88 ‘ Farm Insects,’ p. 45-46.
69 ‘ Observations on N. American Neuroptera,’ by H. Hao-en and B. Walsh, ‘ Proc. Ent. Soc. Philadelphia,’ Oct. 1863, p. 168, 223, 239.
70 ‘ Proc. Ent. Soc. London,’ Feb. 17, 1868.
C«AP. VIII.
SEXUAL SELECTION.
315
and therefore appear to be the more numerous. This is actually the case with a few species ; but he mentions several species in six Sonera, in which the females appear to bo much more numerous than the males.71 The small size of the males in comparison with die females, which is sometimes carried to an extreme degree, and 'heir widely different appearance, may account in some instances f°r their rarity in collections.72
Some of the lower Crustaceans are able to propagate their kind Sexually, and this will account for the extreme rarity of the males. With some other forms (as with Tanais and Cypris) there is reason *0 believe, as Fritz Muller informs me, that the male is much shortcr- Wd than the female, which, supposing the two sexes to be at first equal in number, would explain the scarcity of the males. On the other hand this same naturalist has invariably taken, oil the shores of Brazil, far more males than females of the Diastylidie and of °ypridina; thus with a species in the latter genus, (53 specimens Ca'tght the same day, iucluded 57 males ; but he suggests that this Preponderance may be due to some unknown difference in the habits r,f the two sexes. With one of the higher Brazilian oralis, namely a Gelasimus, Fritz Miillcr found the males to be more numerous d*aa the females. The reverse seems to be the case, according to
large experience of Mr. C. Spence Bate, with six common British Ctobs, the names of which he has given me.
On the Power of Natural Selection to regulate the pro- motional Numbers of the Sexes, and General Fertility. — Iff some peculiar cases, an excess in the number of one Sex over the other might be a great advantage to a species, as with the sterile females of social insects, or "ith those auimals in which more than one male is ’e<]uisite to fertilise the female, as with certain cirri- Pedes and perhaps certain fishes. An inequality be- tween the sexes in these cases might have been acquired through natural selection, but from their rarity they **eed not here be further considered. In all ordinary
j, ,l Another great authority in this class, Prof. Tliorell ofUpsala (‘On European Spiders,’ 1809-70, part i. p- 205) speaks as if female spiders were generally commoner than the males.
> See, on this subject, Mr. Pickard-Cainbridge, as quoted in 1 Quarterly °Urnal of Science,’ 1868, p. 429.
316
THE PRINCIPLES OP
Part
cases an inequality would be no advantage or disa«' vantage to certain individuals more than to others; and therefore it could hardly have resulted from natural selection. We must attribute the inequality to tke direct action of those unknown conditions, which wit*1 mankind lead to the males being born in a somewhat larger excess in certain countries than in others, °r which cause the proportion between the sexes to di&eI slightly in legitimate and illegitimate births.
Let us now take the case of a species producing fro#1 the unknown causes just alluded to, an excess of on1' sex — we will say of males — these being superfluous useless, or nearly useless. Could the sexes be equalised through natural selection ? We may feel sure, from characters being variable, that certain pairs would pi0, duce a somewhat less excess of males over females tha» other pairs. The former, supposing the actual numher of the offspring to remain constant, would necessarily produce more females, and would therefore be more pi®" ductive. On the doctrine of chances a greater numW of the offspring ot the more productive pairs would su1' vivo ; and these would inherit a tendency to procrea*® fewer males and more females. Thus a tendency t0" wards the equalisation of the sexes would he brougO about. But our supposed species would by this proces* be rendered, as just remarked, more productive; an1* this would in many cases be far from an advantage* for whenever the limit to the numbers which exist, <1®' peuds, not on destruction by enemies, but on the atnoU1^ of tood, increased fertility will lead to severer comp®*1" tion and to most of the survivors being badly fed. I11 this case, if the sexes were equalised by an increase & the number of the females, a simultaneous decrease i11 the total number of the offspring would be beneficial > and this, I believe, could be effected through natura
C«4P. VJII.
SEXUAL SELECTION.
317
Section in the manner hereafter to be described. The SatQe train of reasoning is applicable in the above, as well as in the following case, if we assume that females instead of males are produced in excess, for 8<ich females from not uniting with males would be superfluous and useless. So it would be with poly- 8amous species, if we assume the excess of females *° be inordinately great.
An excess of either sex, we will again say of the triales, could, however, apparently be eliminated through Natural selection in another and indirect manner, namely an actual diminution of the males, without any in- crease of the females, and consequently without any ^crease in the productiveness of the species. From variability of all characters, we may feel assured ^at some pairs, inhabiting any locality, would produce H rather smaller excess of superfluous males, but an ec|Ual number of productive females. When the off- ering from the more and the less male-productive Intents were all mingled together, none would have any direct advantage over the others ; but those that pro- ^Uc'od few superfluous males would have one great Mirect advantage, namely that their ova or embryos 'vould probably be larger and flner, or their young better nurtured in the womb and afterwards. We see jfes principle illustrated with plants ; as those which ear a vast number of seed produce small ones ; whilst j^ose which bear comparatively few seeds, often produce arge ones well-stocked with nutriment for the use of the ^edlings.73 Hence the offspring of the parents which la<l wasted least force in producing superfluous males
p " I have often been struck with the fact, that in several species of *'iamla the seeds in the capsules which contained only a few were ery much larger than the numerous seeds iu the more productive CaPsules.
SIS
THE PKINCIPLES OF
Part U-
would be the most likely to survive, and would inherit the same tendency not to produce superfluous males? whilst retaining their lull fertility in the production of females. So it woidd be with the converse case of the female sex. Any slight excess, however, of either seS could hardly be checked in so indirect a manner. Nor indeed has a considerable inequality between the sexes been always prevented, as wo have seen in some of the cases given in the previous discussion. In these cases the unknown causes which determine the sex of the embryo, and which under certain conditions lead to the production of one sex in excess over the other, have not been mastered by the survival of those varieties which were subjected to the least waste of organised matter and force by the production of superfluous indi- viduals of either sex. Nevertheless we may conclude that natural selection will always tend, though some- times inefficiently, to equalise the relative numbers of the two sexes.
Having said this much on the equalisation of the sexes, it may be well to add a few remarks on the regular lion through natural selection of the ordinary fertility of species. Mr. Herbert Spencer has shewn in an abl® discussion ‘4 that with all organisms a ratio exists be- tween what he calls individuation and genesis; whence it follows that beings which consume much matter of force in their growth, complicated structure or activity? or which produce ova and embryos of large size, °r which expend much energy in nurturing their young? cannot be so productive as beings of an opposite nature- Mr. Spencer further shews that minor differences in let' tility will be regulated through natural selection. Th«s the fertility of each species will tend to increase, from
‘ Principles of Biology,’ vol. ii. 1867, chaps, ii.-xi.
SEXUAL SELECTION.
319
Cb.
Ap. VIII.
more fertile pairs producing a larger number of off- ering, and these from their mere number will have the “est chance of surviving, and will transmit their ten- ancy to greater fertility. The only check to a con- tinued augmentation of fertility in each organism seems to be either the expenditure of more power and the heater risks run by the parents that produce a more ’’Utnerous progeny, or the contingency of veiy numerous eSgs and young being produced of smaller size, or less v*gorons, or subsequently not so well nurtured. To strike a balance in any case between the disadvantages "'hid, follow from the production of a numerous pro- geny, and the advantages (such as the escape of at least s°iue individuals from various dangers) is quite beyond ,J’lr power of judgment.
When an organism has once been rendered extremely Wtile, how its fertility can be reduced through natural Election is not so clear as how this capacity was first Squired. Yet it is obvious that if individuals of a 8Pecies, from a decrease of their natural enemies, were ^abitually reared in larger numbers than could be sup- ported, all the members would suffer. Nevertheless the °%>ring from the less fertile parents would have no Effect advantage over the offspring from the more fer- tile parents, when all were mingled together in the district. All the individuals would mutually tend P' starve each other. The offspring indeed of the less |®rtile parents would lie under one great disadvantage, f°1' from the simple fact of being produced in smaller ’(Umbers, they would be the most liable to extermina- tion. Indirectly, however, they would partake of one §reat advantage ; for under the supposed condition of Severe competition, when all ivere pressed for food, it is ^treinely probable that those individuals which from ^'Uie variation in their constitution produced fewer eggs
320 THE PRINCIPLES OF SEXUAL SELECTION. PAET H
or young, would produce them of greater size or vigour; and the adults reared from such eggs or young would manifestly have the best chance of surviving, and would inherit a tendency towards lessened fertility- The parents, moreover, which had to nourish or provide for fewer offspring would themselves be exposed to » less severe strain in the struggle for existence, and would have a better chance of surviving. By tliesu steps, and by no others as far as I can see, natural selection under the above conditions of severe coni' petition for food, would lead to the formation of a lie" race less fertile, but better adapted for survival, than the parent-race.
C>UP. IX.
SEXUAL SELECTION.
321
CHAPTER IX.
Secondary Sexual Characters in the Lower Classes of the Animal Kingdom.
Hose characters absent in the lowest classes i'rillifiut colours Mollusca — Annelids — Crustacea, secondary sexual characters strongly developed ; dimorphism ; colour; chaiacters not acquired before maturity — Spiders, sexual colours of; stridulation by the males — Myriapoda.
^ the lowest classes the two sexes are not rarely united in the same individual, and therefore secondary sexual characters cannot he developed. In many cases in which die two sexes are separate, both are permanently at- tached to some support, and the one cannot search or struggle for the other. Moreover it is almost certain that these animals have too imperfect senses and hiuch too low mental powers to feel mutual rivalry, °r to appreciate each other’s beauty or other attrac- tions.
Hence in these classes or sub-bin gdoms, such as the •Protozoa, Ocelenterata, Echinodermata, Scolecida, true secondary sexual characters do not occur ; and this fact agrees with the belief that such characters in the higher classes have been acquired through sexual selec- tion, which depends on the will, desires, and choice ot either sex. Nevertheless some few apparent exceptions °ccur; thus, as I bear from Dr. Baird, the males of certain Eutozoa, or internal parasitic worms, differ slightly in colour from the females ; hut we have no reason to suppose that such differences have been augmented through sexual selection.
VOL. i.
Y
322
SEXUAL SELECTION.
Part II.
Many of the lower animals, whether hermaphrodites or with the sexes separate, are ornamented with the most brilliant tints, or are shaded and striped in an elegant manner. This is the case with many coral-' and sea-anemonies ( Actiniae), with some jelly-fish (Me- dusae, Porpita, &c.), with some Planarke, Ascidians, numerous Star-fishes, Echini, &c. ; but we may conclude from the reasons already indicated, namely the union of the two sexes in some of these animals, the per- manently affixed condition of others, and the loW mental powers of all, that such colours do not serve as a sexual attraction, and have not been acquired through sexual selection. With the higher animals the case is very different ; for with them when one sex is much more brilliantly or conspicuously coloured than the other, and there is no difference in the habits of the two sexes which will account for this difference, we have reason to believe in the influence of sexual selection ; and this belief is strongly con- firmed when the more ornamented individuals, which are almost always the males, display their attractions before the other sex. We may also extend this con- clusion to both sexes, when coloured alike, if their colours are plainly analogous to those of one sex alone in certain other species of the same group.
How, then, are we to account for the beautiful °r even gorgeous colours of many animals in the lowest classes ? It appears very doubtful whether such colours usually serve as a protection ; but we are extremely liable to err in regard to characters of all kinds i,J relation to protection, as will be admitted by every one who has read Mr. Wallace’s excellent essay on tbis subject. It would not, for instance, at first occur t° any ons that the perfect transparency of the Medus®> or jelly-fishes, was of the highest service to them as *a
Ohap. IX.
SEXUAL SELECTION.
323
protection ; but when we are reminded by Hackel that not only the medusae but many floating mollusca, crus- taceans, and even small oceanic fishes partake of this same glass-like structure, we can hardly doubt that they thus escape the notice of pelagic birds and other enemies.
Notwithstanding our ignorance how far colour in many cases serves as a protection, the most probable view in regard to the splendid tints ot many of the lowest animals seems to be that their colours aie the direct result either of the chemical nature oi the minute structure of their tissues, independently of any benefit thus derived. Hardly any colour is finer than that of arterial blood ; but there is no reason to suppose that the colour of the blood is in itself any advantage ; and though it adds to the beauty of the maiden’s cheek, no one will pretend that it has been acquired for this pur- pose. So again with many animals, especially the lower ones, the bile is richly coloured ; thus the extreme beauty of the Eolidm (naked sea-slugs) is chiefly due, as I am informed by Mr. Hancock, to the biliary glands 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 every one as gorgeous ; yet no one sup- poses that these tints are of the least advantage to the trees. Bearing in mind how many substances closely analogous to natural organic compounds have been recently formed by chemists, and which exhibit the most splendid colours, it would have been a strange fact if substances similarly coloured had not often originated, independently of any useful end being thus gained, in the complex laboratory of living
organisms.
324
SEXUAL SELECTION.
Part II.
The sub-lcingdom of the Moll'usca. — Throughout this great division (taken in its largest acceptation) of the animal kingdom, secondary sexual characters, such as we are here considering, never, as far as I can discover, occur. Nor could they be expected in the three lowest classes, namely in the Aseidians, Polyzon, and Brachio- pods (constituting the Molluscoida of Huxley), 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, hermaphro ditism is not rare. In the next higher class of the Gasteropoda, or univalve shells, the sexes are either united or separate. But in this latter case the males never possess special organs for finding, securing, or charming the females, or for fighting with other males. The sole external difference between the sexes consists, as I am informed by Mr. Gwyn Jeffrevs, in the shell sometimes differing a little" in form ; ' for instance, the shell of the male periwinkle ( Littorin ® littore'a ) is narrower and has a more elongated spire than that of the female. But differences of this nature, it may be presumed, are directly connected with the act of reproduction or with the development of the ova.
The Gasteropoda, though capable of locomotion and furnished with imperfect eyes, do not appear to be eu- dowed with sufficient mental powers for the members of the same sex to struggle together in rivalry, and thus to acquire secondary sexual characters. Never- theless with the pulmoniferous gasteropods, or land- snails, the pairing is preceded by courtship ; for these animals, though hermaphrodites, are compelled by their structure to pair together. Agassiz remarks,1 “Qui- “ conque a eu 1 occasion d’observer les amours des lima-
1 * De l’Esptce et de la Class.’ &c., 1869, p. 106.
C«AP. IX.
MOLLUSCS.
325
“ Qons, ne saurait mettre en doute la seduction deployee “dans les mouvements et les allures qui preparent et “ accomplissent le double einbrasseinent de ces ber- “ maphrodites.” These animals appear also susceptible °f some degree of permanent attachment: an accurate observer, Mr. Lonsdale, informs me that lie placed a Pair of land-shells ( Helix pomatia), one of which was "'Giddy, into a small and ill-provided garden. After a sbort, 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 successful exploration, for both then started along the same track and disap- peared over the wall.
Even in the highest class of the Mollusca, namely the Cephalopoda or cuttle-fishes, in which the sexes are Separate, secondary sexual characters of the kind which Vve are here considering, do not, as far as I can discover, 0ccur. This is a surprising circumstance, as these afomals possess highly-developed sense-organs and have e°nsiderable mental powers, as will be admitted by "Very one who has watched their artful endeavours to escape from an enemy.2 Certain Cephalopoda, however, ai'6 characterised by one extraordinary sexual character, hatnely, that the male element collects within one of foe arms or tentacles, which is then cast off, and, Ringing by its sucking-discs to the female, lives for a ^me 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 T>^e6, ^OT distance, the account wliich I have given in my 1 Journal Researches,’ 1845, p. 7.
326
SEXUAL SELECTION.
Pakt II-
of Hectocotyle. But this marvellous structure may he classed as a primary rather than as a secondary sexual character.
Although with the Mollusea sexual selection does not seem to have come into play ; yet many univalve and bivalve shells, such as volutes, cones, scallops, &c., ate beautifully coloured and shaped. The colours do not appear in most cases to be of any use as a protection ; they are probably the direct result, as in the lowest classes, of the nature of the tissues; the patterns and the sculpture of the shell depending on its manner o» growth. The amount of light seems to a certain extent to be influential; for although, as repeatedly stated by Mr. Gwyn Jeffreys, the shells of some species living at a profound depth are brightly coloured, yet we generally see the lower surfaces and the parts covered by the mantle less highly coloured than the upper and exposed surfaces.3 In some cases, as with shells living amongst corals or brightly-tinted sea-weeds, the bright colon1'3 may serve as a protection. But many of the nudibrand1 mollusea, or sea-slugs, are as beautifully coloured llS any shells, as may be seen in Messrs. Aider and Ha"' cock’s magnificent work ; and from information kindly given me by Mr. Hancock, it is extremely doubt!'1 whether these colours usually serve as a protection With some species this may be the case, as with °D® which lives on the green leaves of algae, and is itse' bright-green. But many brightly-coloured, white t,r otherwise conspicuous species, do not seek concealment
whilst again some equally conspicuous species, as
we'd
as other dull-coloured kinds, live under stones and 1,1
3 I have given (‘Geolog. Observations on Volcanic Islands,’ 18 p. 53) a curious instance of the influence of light on the colours ^ a frondescent incrustation, deposited by the surf on the const-rocls Ascension, and formed by the solution of triturated sea-she-lls.
Chap. IX.
MOLLUSCS AND ANNELIDS.
327
dark recesses. So that with these nudibranch molluscs, colour apparently does not stand in any close relation to the nature of the places which they inhabit.
These naked sea-slug3 are hermaphrodites, yet they pair together, as do laud-snails, many of which have extremely pretty shells. It is conceivable that two hermaphrodites, attracted by each others greater beauty, might unite and leave offspring which would inherit their parents’ greater beauty. l>ut with such lowly- organised creatures this is extremely improbable. Nor is it at all obvious how the offspring from the more beautiful pairs of hermaphrodites would have any ad- vantage, so as to increase in numbers, over the offspring of the° less beautiful, unless indeed vigour and beauty generally coincided. We have not here a number ot males becoming mature before the females, and the more beautiful ones selected by the more vigorous females. If, indeed, brilliant colours ivere 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.
Sub-kingdom of the Vermes : Class, Annelida (or Sea- loorms). — In this class, although the sexes (when separate) sometimes differ from each other in characters ol such importance that they have been placed under distinct genera or even families, yet the differences do not seem of the kind which can be safely attributed to sexual selection. These animals, like those in the pre- ceding classes, apparently stand too low in the scale, f,m the individuals of either sex to exert any choice in selecting a partner, or for the individuals of the same Slx to struggle together in rivalry.
32S
SEXUAL SELECTION.
Part It
Sub-kingdom of the Arthropoda : Class, Crustacea. — In this great class we first meet with undoubted se- condary sexual characters, often developed in a remark' able manner. Unfortunately the habits of crustaceans are very imperfectly known, and we cannot explain the uses of many structures peculiar to one sex. With the lower parasitic species the males are of small size, nd they alone are furnished with perfect swimming- legs, antennoe and sense-organs ; the females being destitute of these organs, with their bodies often consist- ing of a mere distorted mass. But these extraordinary differences between the two sexes are no doubt related to their widely different habits of life, and consequently do not concern us. In various crustaceans, belonging to distinct families, the anterior antennae are furnished with peculiar thread-like bodies, which are believed to act as smelling-organs, and these are much more nume- rous 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 smell- ing-threads has probably been acquired through sexual selection, by the better provided males having been the most successful in finding partners and in leaving off- spring. Fritz Muller has described a remarkable dimor- phic species of Tanais, in which the male is represented by two distinct forms, never graduating into each other. In the one form the male is furnished with more numerous smelling-threads, and in the other form with more powerful and more elongated cheke or pincers which serve to hold the female. Fritz Muller sumresF that these differences between the two male forms of the same species must have originated in certain individuals having varied in the number of the smelling-threads, whilst other individuals varied in the shape and size of
C»AI>, IX.
CRUSTACEANS.
329
their diel® ; so that of the former, those which were best able to find the female, and of the latter, those which were test able to hold her when found, have left the greater number of progeny to inherit their respec- tive advantages.4
In some of the lower crusta- ceans, the right-hand anterior a*>tenna of the male differs greatly in structure from the left-hand one, the latter re- sembling in its simple tapering joints the antennae of the fe- male. In the male the modi- fied antenna is either swollen in the middle or angularly bent,
°r converted (tig. 3) into an degant, and sometimes wonder- fully complex, prehensile organ.5 If serves, as I hear from Sir J.
Lubbock, to hold the female, aud for this same purpose one °f the two posterior legs (b) ou the same side of the body is converted into a forceps. In aUother family the inferior or posterior antennae are “ curiously zigzagged in the ^ules alone.
4 ‘ Facts and Arguments for Darwin,’ English Iranslat. 1869, p. 20. the previous discussion on the olfactory threads. Sara has de-
bribed a somewhat analogous case (as quoted in ‘Nature, 18/0, It 455) in a Norwegian crustacean, the Pontoporcia affinis.
5 See Sir J. Lubbock in ‘Annals, and Mag. of Nat. Hist.’ vol. xi. J853, pi. i. aild x. ; and vol. xii. (1853) pi. vii. _ See also Lubbock in
transact. Ent. Soc.’ vol. iv. new series, 18oG-1858, p. 8. "W itli respect ^ tlie zigzagged antennse mentioned below, see Fritz Muller, ‘Facts and Arguments for Darwin ’ 1869, p. 40, foot-note.
a
Fig. 3. Labidocera Darwini! (from Lubbock).
a. Part of rigbt-band anterior an-
tenna of male, forming a pre- hensile organ.
b. Posterior pair of thoracic legs of
male.
c. Ditto of female.
SEXUAL SELECTION.
Pari' II
In the higher crustaceans the anterior legs form a pair of chelae or pincers, and these are generally larger in the male than in the female. In many species the chelae on the opposite sides of the body are of unequal size, tie right-hand one being, as I am iu"
UR— The artist by mistake hus reversed the drawing, and made the left-hand chr|11 thp largest.
Hg. 5. Second leg of male Orchestiu Tucuratinga (from Fritz Muller).
Fig. 6. Ditto of female.
formed by Mr. 0. Spence Bate, generally, though invariably, the largest. This inequality is often much greater in the male than in the female. The two chehe also often differ in structure (figs. 4 and 5, b'), the small®1' one resembling that of the female. What advantage
Chap. IX.
CRUSTACEANS.
331
is gained by their inequality in size on the opposite sides of the body, and by the inequality being much greater in the male than in the female ; and why, when they are of equal size, both are often much larger in the male than in the female, is not known. The ckelte are sometimes of such length and size that they cannot possibly be used, as I hear from Mr. Spence Bate, for carrying food to the mouth. In the males of certain fresh- water prawns (Pakemon) the right leg is actually longer than the whole bo: ly.6 It is probable that the great size of one leg with its chela: may aid the male in fighting with his rivals; but this use will not account for their inequality in the female on the opposite sides of the body. In Gelasimus, according to a statement quoted by Milne- Edwards,7 the male and female live in the same burrow, which is worth notice, as shewing that they pair, and the male closes the mouth of the burrow with one of its oh el to, which is enormously developed ; so that here it indirectly serves as a means of defence. Their main Use, however, probably is to seize and to secure the female, and this in some instances, as with Gammarus, is known to be the ease. The sexes, however, of the common shore-crab ( Garcinus mamas), as Mr. Spence Bate informs me, unite directly after the female has Moulted her hard shell, and 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 previously to the act of moulting, she could then
be seized with impunity. _
Fritz Muller states that certain species of Melita are
8 See a paper by Mr. 0. Spence Bate, with figures, in ‘Proe. Zoolog. Soc.’ 1S68 o 363' and on the nomenclature of tlie genus, ibid. p. 080. I am greatly indebted to Mr. Spence Bate for nearly all the above statements with respect to the clielee of the higher crustaceans.
7 ‘ Hist. Nat. des Crust.’ tom. ii. 1837, p. 50.
332
SEXUAL SELECTIOX.
Part II-
distinguished from all other amphipods by the females having “the coxal lamellae of the penultimate pair of “ 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 probably resulted from those females which were the most securely held during tire act of reproduction, having left the largest number of offspring. Another Bra- zilian ampldpod ( Orchestia DarwinU, fig. 7) is de- scribed by Fritz Muller, as presenting a case of dimor- phism, like that of Tanais; for there are two male forms, which differ in the structure of their cliche.8 As chelte of either shape would certainly have sufficed to hold tlio female, for both arc now used for this purpose, the two male forms probably originated, by some having varied in one manner and some in another; both forms having derived certain special, but nearly equal advan- tages, from their differently shaped organs.
It, is not known that male crustaceans fight together for the possession of the females, but this is probable ; lot with most animals when the male is larger than the female, ho seems to have acquired his greater size by having conquered during many generations other males. Now Mr. Spence Bate informs me that in most of the crustacean orders, especially in the highest or the Brachyura, the male is larger than the female; the parasitic genera, however, in which the sexes follow different habits of life, and most ol the Entomostraca must be excepted. The chelas of many crustaceans are weapons well adapted for fighting. Thus a Devil-crab (Portunus puber) was seen by a sou of Mr. Bate fighting wdh a Carcinus mamas, and the latter was soon thrown on its back, and had every limb torn from its body-
8 Fritz II filler, ‘Facts and Arguments for Darwin,’ 1869, p. 25-28.
C>Up. IX.
CRUSTACEANS.
333
^hen several males of a Brazilian Gelasimus, a species j^rnished with immense pincers, were placed together |Jy Fritz Muller in a glass vessel, they mutilated and billed each other. Mr. Bate put a large male Carcinus
P\
e* 7- Orchestia Darwinll (from Fritz Mttller), showing the differently-constructed cliche of the two mule forms.
n,bna& into a pan of water, inhabited by a female paired jVhh a smaller male ; the latter was soon dispossessed, Ut> as Mr. Bate adds, “ if they fought, the victory
334
SEXUAL SELECTION.
Paet II-
“ was a bloodless one, for I saw no wounds.” This same naturalist separated a male sand-skipper (so coin' mon on our sea-shores), Gammarus marinus, from its female, both of which were imprisoned in the satD® vessel with many individuals of the same species. Th® female being thus divorced joined her comrades. Aft®r an interval the male was again put into the sam® vessel and he then, after swimming about for a time* dashed into the crowd, and without any fighting at one® took away his wife. This fact shews that in the AmphJ' poda, an order low in the scale, the males and femaleS recognise each other, and are mutually attached.
The mental powers of the Crustacea are probably higher than might have been expected. Any one w h° has tried to catch one of the shore-crabs, so numero«s on many tropical coasts, will have perceived how war?' and alert they are. There is a large crab (Bir03 latro), found on coral islands, which makes at th® bottom of a deep burrow a thick bed of the pick®® fibres of the cocoa-nut. It feeds on the fallen fruit ot" this tree by tearing off the husk, fibre by fibre; it always begins at that end where the three cy®' like depressions are situated. It then breaks through one of these eyes by hammering with its heavy fro®1 pincers, and turning round, extracts the albumin®’15 core with its narrow posterior pincers. But these actio®6 are probably instinctive, so that they would be p®1 formed as well by a young as by an old anin®1 * The following case, however, can hardly be so c®11 sidered : a trustworthy naturalist, Mr. Gardner,9 whus watching a shore-crab (Gelasimus) making its burro*’
• ‘Travels in the Interior of Brazil,’ 1846, p. 111. I have g-iven,^^ my ‘ Journal of Besearches,’ p. 463, an account of the habits of Birgos.
CRUSTACEANS.
335
CiUt>. IX.
threw some shells towards the hole. One rolled in, a“d three other shells remained within a few inches of the mouth. In about live minutes the crab brought the shell which had fallen in, and carried it away t° the distance of a foot; it then saw the three other shel]g lying near, and evidently thinking that they '^ight likewise roll in, carried them to the spot where 't had laid the first. It would, I think, be difficult to distinguish this act from one performed by man by the ai(l of reason.
With respect to colour which so often differs in the Wo sexes of animals belonging to the higher classes, Spence Bate does not know of any well-marked '“stances with our British crustaceans. In some cases, lowever, the male and female differ slightly in tint, (“t Mr. Bate thinks not more than may be accounted by their different habits of life, such as by the '“ale wandering more about and being thus more ex- ited to the light. In a curious Bornean crab, which '“habits sponges, Mr. Bate could always distinguish the s“Xcs by the male uot having the epidermis so much bibbed off. Dr. Power tried to distinguish by colour sexes of the species which inhabit the Mauritius, but “Ways failed, except with one species of Squilla, pro- Jably the S. stylifera, the male of which is described as >oing «0f a beautiful blueish-green,” with some of the appendages cherry-red, whilst the female is clouded Wli brown and grey, “with the red about her much less vivid than in the male.”10 In this case, we may s“spect the agency of sexual selection. With Sa- P“ifina (an oceanic genus of Eutomostraca, and tliere- °re low in the scale) the males are furnished with
k Mr.
Mr. Ch. Eraser, in ‘Proc. Zoolog. Soc.’ 1869, p. I
• Bate for the statement from Dr. Power.
I am indebted
336
SEXUAL SELECTION.
Part H-
minute shields or cell-like bodies, which exhibit beaU' tiful changing colours ; these being absent in the females, and in the case of one species in both sexes. It would, however, be extremely rash to conclude that these curious organs serve merely to attract the females- In the female of a Brazilian species of Gela-simus, the whole body, as I am informed by Fritz Muller, is of fl nearly uniform greyish-brown. In the male the posterior part of the cephalo-thorax is pure white, with the anterior part of a rich green, shading into dark brown - and it is remarkable that these colours are liable t° change in the course of a few minutes— the whit0 becoming dirty grey or even black, the green “losing much of its brilliancy.” The males apparently a*0 much more numerous than the females. It deserve* especial notice that they do not acquire their bright colours until they become mature. They differ a'*0 from the females in the larger size of their cheh0- In some species of the genus, probably in all, th0 sexes pair and inhabit the same burrow. They ar0 also, as we have seen, highly intelligent animate' From these various considerations it seems higb^ probable that the male in this species has becon,e gaily ornamented in order to attract or excite tl'e
female.
It has just been stated that the male Gelasimus doe* not acquire his conspicuous colours until mature olH nearly ready to breed. This seems the general rule 10 the whole class with the many remarkable difference’" in structure between the two sexes. We shall he>’^ after find the same law prevailing throughout the g1^ sub-kingdom of the Vertebrata, and in all cases it 9 eminently distinctive of characters which have bet'11
11 Claus, 1 Die freilebenden Copepoden,’ 1S63, s. 35.
C«AP. IX.
SPIDEKS.
337
acquired through sexual selection. Fritz Muller12 gives Some striking instances of this law; thus the male sand-hopper (Orchestia) does not acquire his large claspers, which are very differently constructed from those of the female, until nearly full-grown; whilst young his claspers resemble those of the female. Thus, again, the male Brachyscelus possesses, like all other ainphipods, a pair of posterior antennas ; the female, and this is a most extraordinary circumstance, is desti- tute of them, and so is the male as long as he remains ^nmature.
Class, Arachnida (Spiders).— The males are often darker, hut sometimes lighter than the females, as may he seen in Mr. Blackwall’s magnificent work.13 In some species the sexes differ conspicuously from each °ther in colour ; thus the female of Sparassus sma- Ta!/dulus is dullish-green ; whilst the adult male has the abdomen of a fine yellow, with three longitudinal Bi'ipes of rich red. In some species of Tliomisus the hvo sexes closely resemble each other ; in others they differ much; thus in T. citreus the legs and body of the female are pale-yellow or green, whilst the front legs of the male are reddish-brown: in T. floricolens, the legs of the female are pale-green, those of the ^ale being riuged in a conspicuous manner with various tints. Numerous analogous cases could be given in the genera Epeira, Nephila, Pbilodromus, Theridion, Liny- pliia, &c. It is often difficult to say which of the two Sexes departs most from the ordinary coloration of the genus to which the species belong; but Mr. Elackwall
12 ‘ Facts and Arguments,’ &c., p. 79.
13 ‘ A History of the Spiders of Great Britain,’ 1861-G4. For the blowing facts, see p. 102, 77, 88.
VOL. I.
2
338
SEXUAL SELECTION.
Pabt II-
thinks that, as a general rule, it is the male. Both sexes whilst young, as I am informed by the same author, usually resemble each other ; and both often undergo great changes in colour during their successive moults before arriving at maturity. In other cases the male alone appears to change colour. Thus the male of the above-mentioned brightly-coloured Spn* rassus at first resembles the female and acquires biS peculiar tints only when nearly adult. Spiders ate possessed of acute senses, and exhibit much intelb' gence. The females often shew, as is well known, the strongest affection for their eggs, which they carry about enveloped in a silken web. On the whole ’t appears probable that well-marked differences in colon1' between the sexes have generally resulted from sexual selection, either on the male or female side. But doubts may be entertained on this head from the extreffl0 variability in colour of some species, for instance of Theridion lineatum, the sexes of which differ when adult ; this great variability indicates that their colours have not been subjected to any form of selection.
Mr. Blackwall does not remember to have seen th0 males of any species fighting together for the posses' sion of the female. Nor, judging from analogy, is tin- probable ; for the males are generally much smaHel than the females, sometimes to an extraordinary do' gree.14 Had the males been in the habit of fightiu- together, they would, it is probable, have graduallj
14 Aug. Vinson (‘Arane'ides des Ilea de la Reunion,’ pi. vi. fig3-, and 2) gives a good instance of the small size of the male in 2 Vpei nigra. In this species, as I may add, the male is testaceous and 4 female black with legs banded with red. Other even more strik>De cases of inequality in size between the sexes have been recon (‘ Quarterly Journal of Science,’ 1868, July, p. 429); but I have not see the original accounts.
Char -lx.
SPIDERS AND MYRIAPODA.
339
acquired greater size and strength. Mr. Blackwall has sometimes seen two or more males on the same web With a single female ; hut their courtship is too tedious and prolonged an affair to be easily observed. The male 's extremely cautious in making his advances, as the female carries her coyness to a dangerous pitch. De Geer saw a male that ,ciii the midst of his preparatory ‘‘ caresses was seized by the object of his attentions, “enveloped by her in a web and then devoured, a “ sight which, as he adds, filled him with horror and “ indignation.” 15
Westring has made the interesting discovery that the males of several species of Theridion1® have the power of making a stridulating sound (like that made by many beetles and other insects, but feebler), whilst the females are quite 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 could be detected in the females. 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 remarks, either to call or to excite the female ; °and this is the first case in the ascending scale of the animal kingdom, known to me, of sounds emitted for this purpose.
Class, Myriapoda— In neither of the two orders in this class, including the millipedes and centipedes,
15 Kirby and Spence, ‘ Introduction to Entomology,’ vol. i. 1818, P. 280.
16 Tlieridion (Asageaa, Sund.) serratipes, 4-punctatum et guttatum; See Westring, in Kroyer, ‘ Naturhist. Tidskrift,’ vol. iv. 1842-1843, P- 349 ; and vol. ii. 1846-1849, p. 342. See, also, for other species,
Aranese Svecic®,’ p. 184.
z 2
340
SEXUAL SELECTION.
Part II-
can I find any well-marked instances of sexual dif- ferences such as more particularly concern us. In Glomeris Imibata, however, and perhaps in some fen other species, the males differ slightly in colour from the females; but this Glomeris is a highly variable species. In the males of the Diplopoda, the legs be- longing to one of the anterior segments of the body, or to the posterior segment, are modified into prehensile hooks which serve to secure the female. In some species of lulus the tarsi of the male are furnished with membranous suckers for the same purpose. It is a much more unusual circumstance, as we shall see when we treat of Insects, that it is the female in Lithobius which is furnished with prehensile appen- dages at the extremity of the body for holding the male. 17
11 Walckenaer et P. Gervais, ‘Hist. Nat. des Insectes : Apt'eres, torn. iv. 1S47, p. 17, 19, GS.
Chap. X.
SEXUAL SELECTION.
341
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 lliysanura
— Diptera Hemiptera — Homoptera, musical Dowers possessed
by the males alone — Orthoptora, musical instruments of the males, much diversified in structure; pugnacity; colours — Neuroptera, sexual differences in colour — Hymenoptera, pugnacity and colours — Coleoptera, colours ; furnished with great horns, apparently as an ornament ; battles ; stridulating organs generally common to both sexes.
Iff the immense class of insects the sexes sometimes differ in their organs for locomotion, and often in tlieir sense-organs, as in the pectinated and beauti- fully plumose antennae of the males of many species, hi one of the Ephemerae, namely Chloeon, the male has great pillared eyes, of which the female is entirely destitute.1 The ocelli are absent in the females of certain other insects, as in the Mutillidce, which are likewise destitute of wings. But we are chiefly con- cerned with structures by which one male is enabled to Ampler another, either in battle or courtship, through |us strength, pugnacity, ornaments, or music. The innumerable contrivances, therefore, by which the male ':s able to seize the female, may be briefly passed over, besides the complex structures at the apex ol the abdo- men, which ought perhaps to be ranked as primary
’ Sir J. Lubbock, ‘ Transact. Linnean Soc.’ vol. xxv. 1866, p. 484 respect to tlie Mutillidae see Westwood, ‘ Modem Class, of Insects,’ Vo1- ii. p. 213.
342
SEXUAL SELECTION.
Part II.
organs,2 “it is astonishing,” as Mr. B. I). Walsli3 has remarked, “how many different organs are worked in “by nature, for the seemingly insignificant object of “ enabling the male to grasp the female firmly.” The mandibles or jaws are sometimes used for this purpose ; thus the male Corydalis eornuius (a ueuropterous insect in some degree allied to the Dragon flies, &c.) has im- mense curved jaws, many times longer than those of the female ; and they are smooth instead of being toothed, by which means he is enabled to seize her without injury.'’ One of the stag-beetles of North America (Lucanus elaphus ) uses his jaws, which are much larger than those of the female, for the same purpose, but probably likewise for fighting. In one of the sand- wasps (Arnrnoph'ila) the jaws in the two sexes are closely alike, but are used for widely different purposes; the males, as Professor Westwood observes, “are exceed- “ ingly ardent, seizing their partners round the neck “ with their sickle-shaped jaws ; ” 5 whilst the females use
5 These organs in the male often differ in closely-allied species, #i'd afford excellent specific characters. Hut their importance, under !l functional point of viow, as Mr. R. MacLaehlan lias remarked to tin • lias probahl.v been overrated. It has been suggested, that slight ‘111- ferencea in these organs would suffice to prevent the intercrossing nt well-marked varieties or incipient species, and would thus aid in tlicir development. 1'hat this can hardly be the case, we may infer from tb* many recorded eases (see for instance, Bronn, ‘Geschichte der Natur- B. ii. 1813, s. Kit; and Westwood, ‘Transact. Eat. 8oc.' vol. iii. lSi% p. I Do) of distinct species having been observed in union. SB- MacLaehlan informs me vide ‘Skit. Ent. Ztitung,’ 1867. s. 155) that when several species of Phryganidre. which present stiongly-prououn<’el1 differences of litis kind, were confined together by Dr. Aug. Mcyt‘r’ thei/ wm'pled, and one. pair produced fertile ova.
s ‘Tho Practical Entomologist,’ Philadelphia, vol. ii. May, 186T» p. 88.
4 Mr. Walsh, ibid. p. 107.
5 ‘Modern Classification of Insects,’ vol. ii. 1840, p. 206,205. ^T‘ Walsh, who called my attention to this double use of the jaws, s"ys that he has repeatedly observed this fact.
INSECTS.
343
C‘UP. X.
these organs for burrowing in sand-banks and making
their nests. .
The tarsi of the front-legs are dilated m 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 female. It is a much more Unusual circumstance that the females of some water- beetles (Dytiseus) have their olytra deeply grooved, and in Acilius sulcatus thickly set with hairs, as an aid to the male. The females of some other water-beetles (Hydro- porus) have their elytra Punctured for the same ob- ject.8 In the male of Cnibro crtbrarius (fig. 8.), it is the tibia which is dilated into a broad horny plate, with mi- Unte membraneous dots, giv- iiig to it a singular appear- ance like that of a riddle.'
In the male of Penthe (a genus ot beetles) a lew 0I ' maUs. ^figure, female, fbe middle joints of the an-
teimar are dilated and furnished on the inferior surface
8 We have here a euiiona ana Inexplicable ease of dimorphism, for s«me of the females of four European species of Dytiseus, and of certain species of Hydroporus, have their elytra smooth; and no intermediate gradations between sulcated or punctured and quite smooth elytra We been observed. See Dr. H. Schaiun, as quoted in the Zoologist, Vol. y.-vi. 1847-18, p. 1896. Also Kirby o.u<l Spence, ‘Introduction to Eutomology/ vol. iii. 1826, p. 305. . m1 „
7 Westwood, * Modern Class/ vol. ii. p. 193. The following state- ment about rent lie, and others in inverted commas, are taken from Walsh, ‘Practical Entomologist, Philadelphia, vol, ii. p. 8S,
344
SEXUAL SELECTION.
Part It
with cushions of hair, exactly like those on the tarsi of the Carabidse, “ and obviously for the same end.” In male dragon-flies, “ the appendages at the tip of the tail “ are modified in an almost infinite variety of curious “ patterns to enable them to embrace “ the neck of the female.” Lastly in the males of many insects, the legs are furnished with peculiar spines, knobs or spurs; or the whole leg is bowed or thickened, but this is by no means invariably a sexual cha- racter ; or one pair, or all three pairs are elongated, sometimes to an extravagant length.8
In all the orders, the sexes of many species present differences, of which the meaning is not under- stood. One curious case is that of a beetle (fig. 9), the male of which has the left mandible much en- larged ; so that the mouth is greatly distorted. In another Carabidous beetle, the Eurygnathus,9 we have the unique case, as far as known to Mr. Wollaston, of the head of the female being much broader and larger, though in a variable degree, than that of the male. Any number of such cases could be given. They abound in the Lcpidopteia : ' one of the most extraordinary is that certain male butterflies have their fore-le"s more or
O
Fig. 9. Taphroderos distortus (much enlarged). Upper figure, male ; lower figure , female.
8 Kirby and Spence, ‘In fcroduct.’ &c„ vol. iii. p. 332-336.
9 ‘ Insecta Maderensia,’ 1854, p. 20.
Chap. X.
INSECTS.
345
less atrophied, with the tibiae and tarsi reduced to mere rudimentary knobs. The wings, also, in the two sexes often differ in neuration,10 and sometimes considerably in outline, as in the Arkoris epitus, which was shown to me in the British Museum by Mr. A. Butler. The males of certain South American butterflies have tufts of hair on the margins of the wings, and horny excres- cences on the discs of the posterior pair.11 In several British butterflies, the males alone, as shewn by Mr. Wo n for, are in parts clothed with peculiar scales.
The purpose of the luminosity in the female glow- worm is likewise not understood ; tor it is very doubtful whether the primary use ot the light is to guide the teale to the female. It is no serious objection to this latter belief that the males emit a feeble light; for secondary sexual characters proper to one sex are often developed in a slight degree in the other sex. It is a more valid objection that the larvae shine, and in some species brilliantly : Fritz Muller informs me that the most luminous insect which he ever beheld in Brazil, Was the larva of some beetle. Both sexes of certain luminous species of Elater emit light. Kirby and Spence suspect that the phosphorescence serves to frighten and drive away enemies.
Difference in Size between the Sexes. T\ ilh insects of all kinds the males are commonly smaller than the females;12 and this difference cau often be detected even in the larval state. So considerable is the difference
10 E. Doubleday, 1 Annals and Map:. ofNat. Hist.’ vol. i. 1848, p. 379. I may add that the winsjs in certain Hymenoptera (see Slmckard, 'Eossorial Hymenop.’ 1S37, p. 39-43) differ in neuration according to sex.
11 H. W. Bates, in ‘ Journal of Proc. Linn. Soc.’ vol. yi. 1862, p. 74. Fr. Wonfor's observations are quoted in ‘Popular Science Review, l868, p. 343.
12 Kirby and Spence, ‘ Introduction to Entomology,’ vol. iii. p. 299.
34G
SEXUAL SELECTION.
Part II.
between the male and female cocoons of the silk-moth (Bombyx mori), that in Fiance they are separated by a particular mode of weighing.13 In the lower classes ol 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 lias suggested a much more probable explanation. He finds, after carefully attending to the development of the cater- pillars of Bombyx cynthia and yamamai, and especially ol some dwarfed caterpillars reared from a second brood on unnatural food, “that in proportion as the indivi- “ dual moth is finer, so is the time required for its “ metamorphosis longer ; and for this reason the female, “ which is the larger and heavier insect, from having to “ carry her numerous eggs, will be preceded by the “ male, which is smaller and has less to mature.” 14 No'V 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 females; and this again would naturally follow, a3 Mr. A. 11. Wallace has remarked,15 through natural selection; for the smaller males would be first matured, and thus would procreate a large number of offspring which would inherit the reduced size of their male parents, whilst the larger males from being matured later would leave fewer offspring.
There are, however, exceptions to the rule of male insects being smaller than the females; and some of
13 Bobinet, ‘ Vers h Soie,’ 1848, p. 207.
14 ‘Transact. Ent. Soc.’ 3rd series, vol. v. p. 486.
15 ‘ Journal of Proc. Ent. Soc.’ Feb. 4th, 1867, p. lxxi.
C>IAP. X.
INSECTS.
S47
these exceptions are intelligible. Size and strength Would be an advantage to the males, which fight for the possession of the female ; and in these cases the males, as with the stag-beetle (Lucanus), are larger than the females. There are, however, other beetles which are Wot known to fight together, of which the males exceed the females in size; and the meaning of this iact is not known ; but in some of these cases, as with the huge klynastes and Megasoma, we can at least see that there Would be uo necessity tor the males to he smaller than tlie females, in order to he matured before them, for these beetles are not short-lived, and there woulu he •1 tuple time for the pairing of the sexes. So, again, male dragon-flies (Libellulidte) are sometimes sensibly larger, and never smaller, than the females; 18 and they do not, as Mr. MacLachlon believes, generally pair with the females, until a week or fortnight has elapsed, and until they have assumed their proper Wiascnline colours. But the most curious case, shewing °n what complex and easily-overlooked relations, so trifling a character as a difference in size between the sexes may depend, is that of the aculeate Hymenoptera ; for Mr. F. Smith informs me that throughout nearly Ike whole of this large group the males, in accor- dance with the general rule, are smaller than the females and emerge about a week before them , but amongst the Bees, the males of Apis viellifica, Anthidium ^anicatum and Anihophora acervorum, and amongst the k'ossores, the males of the Methoca ichneumonides, are larger than the females. The explanation of this ano- maly is that a marriage-flight is absolutely necessary
16 Eor this and other statements on the size of the sexes, see Kirby aad Spence, ibid. vol. iii. p. 300 ; on the duration of life in insects, See p. 314.
348
SEXUAL SELECTION.
Part II-
with these species, and the males require great strength and size in order to carry the females through the ah'- Increased size has here been acquired in opposition to the usual relation between size and the period of de- velopment, for the males, though larger, emerge before the smaller females.
We will now review the several Orders, selecting such facts as more particularly concern us. The Lepidoptera (Butterflies and Moths) will be retained for a separate chapter.
Order, Tliijsanura.—Uhe members of this Order are lowly organised for their class. They are wingless, dull-coloured* minute insects, with ugly, almost" mis- shapen heads and bodies. The sexes do not differ ; but they offer one interesting fact, by shewing that the males pay sedulous court to their females even low down in the animal scale. SirJ. Bubbock11 in describing th g Snu/ft' thurus luteus, says : “ it is very amusing to see these
little creatures coquetting together. The male, which “ is much smaller than the female, runs round her, and “ they butt one another, standing lace to face, and £' moving backward and forward like two playful lambs- “Then the female pretends to run away and the male “ runs after her with a queer appearance of anger, gets “ in front and stands facing her again ; then she turns “ coyly round, but he, quicker and more active, scuttles “round too, and seems to whip her with his antennae* “then for a hit they stand face to face, play with their “ antennae, and seem to be all in all to one another.”
Order, Biftera (Flies).— The sexes differ little h1 colour. The greatest difference, known to Mr. F. Walker,
17 ‘Transact. Liunean Soc.’ vol. xxvi. 1868, p. 296.
Wap. x.
DIPTEEA AND HEMTPTEKA.
349
18 in the genus Bibio, in which the males are blackish 0r quite black, and the females obscure brownish-orange. The genus Elaphomyia, discovered by Mr. Wallace ls 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 stags, being either branched or palmated. They equal in length the whole of the body in one of the species. They might be thought to serve for fighting, but as in one species they are of a beautiful pink colour, edged with black, with a Pale central stripe, and as these insects have altogether a very elegant appearance, it is perhaps more pro- bable that the horns serve as ornaments. That the dales of some Diptera fight, together is certain ; for Prof. Westwood 19 has several times seen this with some sPecies of Tipula or Harry-long-legs. Many observers believe that when gnats (Oulicidas) dance in the air in a body, alternately rising and falling, the males are courting the females. The mental faculties of the
>, o
1 hptera are probably fairly well developed, for their Nervous system is more highly developed than in most °ther Orders of insects.20
Order, Eemiptera (Field-Bugs).— Mr. J. W. Douglas, " ho has particularly attended to the British species, has biudlv given me an account of their sexual differences. The males of some species are furnished with wings, "didst the females are wingless ; the sexes differ in the f°rm of the body and elytra; in the second joints of their antennae and in their tarsi ; hut as the signification
Is ‘ The Malay Archipelago,’ vol. ii. 1869, p. 313.
19 ‘ Modern Classification of Insects,’ vol. ii. 1840, p. 526.
50 See Mr. B. T. Lowne’s very interesting work, ‘ On tlie Anatomy of Blow-Fly, Mu sea vomitoria,’ 1870, p. 14.
350
SEXUAL SELECTION.
Part II-
of these differences is quite unknown, they may he here passed over. The females are generally larger and more robust than the males. With British, and, as far as Mr. Douglas knows, with exotic species, the sexes do not commonly differ much in colour; but in about six British species the male is considerably darker than the female, and in about four other species the female is darker than the male. Both sexes of some species are beautifully marked with vermilion and black. It is doubtful whether these colours serve as a protection- If in any species the males had differed from the females in an analogous manner, wre might have been justified in attributing such conspicuous colours to sexual selec- tion with transference to both sexes.
Some species ofRednvidse make a strid dating noise! and, in the case of Pirates stridulus , this is said21 to be effected by the movement of the neck within the pro-thoracic cavity. According to Westring, Reduvii i$ personatus also stridulates. But I have not been able to learn any particulars about these insects; nor have I any reason to suppose that they differ sexually in this respect.
Order, Eomoptera. — Every one who has wandered i'1 a tropical forest must have been astonished at the din made by the male Cicada?. The females are mute • as the Grecian poet Xenarchus says, “ Happy the “ Cicadas live, since they all have voiceless wives. The noise thus made could be plainly heard on board the “Beagle,” when anchored at a quarter of a niiD from the shore of Brazil ; and Captain Hancock sa)'s it can be heard at the distance of a mile. The Greek* formerly kept, and the Chinese now keep, these insect*
21 Westwood, ‘Modern Class, of Insects,’ vol. ii. p. 473.
ClIAP. X.
HOMOPTEKA.
351
in cages for tlie sake of their song, so that it must be pleasing to the ears of some men.22 The Cicadidse Usually sing during the day; whilst the Fulgoridse appear to be night-songsters. The sound, according to Landois,-' who has recently studied the subject, is produced by the vibration of the lips of the spiracles, which are set into motion by a current of air emitted from the trachea?. It is increased by a wonderfully complex resounding apparatus, consisting of two cavi- ties covered by scales. Hence the sound may truly be called a voice. In the female the musical apparatus is present, but very much less developed than in the ttiale, 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,24 “the drums are now (June 6th and 7th, “ 1851) heard in all directions. This I believe to be the “ marital summons from the males. Standing in thick “ chestnut sprouts about as high as my head, where “ hundreds were around me, I observed the females ‘‘ coming around the drumming males.” He adds, “ this “ season (Aug. 1868) a dwarf pear-tree in my garden “ produced about fifty larvae of Cic. pruinosa ; and I “ several times noticed the females to alight near a “ male while he was uttering his clanging notes.” Fritz ^fuller writes to me Irom S. Brazil that he has often listened to a musical contest between two or three 'Wales of a Cicada, having a particularly loud voice, and seated at a considerable distance from each other. As
22 These particulars are taken from Westwood’s ‘Modem Class, of Insects’ vol, ii. 1840, p. 422. See, also, on the Fulgondas, Kirby and Spence, Introduct.’ vol. ii. p. 401.
23 ‘ Zeitschrift, fur wissenschatt. Zoolog.’ B. xvii. 18G7, s. 152-158.
21 1 am indebted to Mr. Walsh for having sent me this extiact from a ‘ Journal of the Doings of Cicada septemdecim,’ by Dr. Hartman.
352
SEXUAL SELECTION.
''Pabt II-
soon as tlie first had finished his song, a second im- mediately began ; and after he had concluded, another began, and so on. As there is so much rivalry between the males, it is probable that the females not only dis- cover them by the sounds emitted, but that, like female birds, they are excited or allured by the male with the most attractive voice.
I have not found any well-marked cases of orna- mental differences between the sexes of the Hoinoptera. Mr. Douglas informs me that there are three British species, in which the male is black or marked with black bands, whilst the females are pale-coloured or obscure.
Order, Orthopiera. — The males in the three salta- torial families belonging to this Order are remark- able for their musical powers, namely the Achetidie or crickets, the Locustidte for which there is no exact equivalent name in English, and the Acridiidm or grass- hoppers. The stridnlation produced by some of the Locus ti dm is so loud that it can be heard during the night at the distance of a mile;25 and that made bv certain species is not unmusical even to the human ear, so that the Indians on the Amazons keep them in wicker cages. All observers agree that the sounds serve either to call or excite the mute females. But h has been noticed20 that the male migratory locust of Russia (one of the Acridiidse) whilst coupled with the female, stridulates from anger or jealousy when ap" proached by another male. The house-cricket when surprised at night uses its voice to warn its fellows.27 1° North America the Katy-did ( PlatijphyUum concavuw,
25 L. Guilding, 1 Transact. Linn. Soc.’ vol. xv. p. 154.
56 Koppen, as quoted in the 1 Zoological Eecord,’ for 1867, p. 460. 27 Gilbert White, ‘ Nat. Hist, of Selborne,’ vol. ii. 1825, p. 262.
ClUp. X.
ORTHOPTERA.
353
°Re of the Locustidse) is described28 as mounting on the Upper branches of a tree, and in the evening beginning “ his noisy babble, while rival notes issue from the neigh- “ bouring trees, and the groves resound with the call of “ Katij-did-she-did, the live-long night.” Mr. Bates, in Epeaking of the European field-cricket (one of the Ache- bdee). says, “ the male has been observed to place itself “ in the evening at the entrance of its burrow, and “ stridulate until a female approaches, when the louder “ notes are succeeded by a more subdued tone, whilst “ the successful musician caresses with his antennas “the mate he has won.”2'J Or. Scudder was able to °Xeito one of these insects 1° answer him, by rubbing °n a file with a quill.80 In both sexes a remark- able auditory apparatus been discovered by Ion Siebold, situated in Hie front legs.31
In the three Families Wle sounds are differently I'fe. 10- Gryllus campestris (from Lnndois), Produced. In the males of Ino Achetidas both wing- c°vers have the same sh'Ucture ; and this in the field-cricket ( Gryllus campestris, fig. 10) consists, as de
llight-lmnd figure, under side of part of the wing-nervure, much magnified, showing the teeth, st.
Left-hand figure, upper surface of wing-cover, with the projecting, smooth nervure, r.t across which the teeth (st) are scraped.
Harris, ‘ Insects of New England,’ 1S12, p. 128.
*9 ‘ The Naturalist on the Amazons,’ vol. i. 1863, p. 252. Mr. Bates a very interesting discussion on the gradations in the musical apparatus of the three families. See also Westwood, ‘Modern Class.’ 7 *>■ p. 415 and 453.
° ‘ Proc. Boston Soc. of Nat. Hist.’ vol. xi. April, 1868.
* 1 ‘Nouveau Manuel d’Anat. Comp.’ (French translat.), tom. i. 1850 P- 567.
yOL. I. 2 A
354
SEXUAL SELECTION.
Part H*
Fig. 11. Teeth of Nervure of Gryllus domesticus (from Lundois).
scribed by Landois,32 of from 131 to 138 sharp, trans- verse ridges or teeth (si) 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 (r) on the upper surface of the opposite wing. First one wing is rubbed over the other, and then the movement is reversed- Both wings are raised a little at the same time, so as to increase the re- sonance. In some species the wing' covers of the males are furnished the base with a talc-like plate.® I have here given a drawing (fig. U) of the teeth on the under side of the nervure of another species of Gryllus, viz. G. domesticus.
In the Locustidie the opposite wing-covers differ h1 structure (fig. 12), and cannot, as in the last family be indifferently used in a reversed manner. The led1 wing, which acts as the bow of the fiddle, lies over the right wing which serves as the fiddle itself. One o*' the nervures (a) on the under surface of the former k finely serrated, and is scraped across the prominent nervures on the upper surface of the opposite or rigid wing. In our British Fhasgonura viridissima it aP' peared to me that the serrated nervure is rubbo against the rounded hind corner of the opposite win-' the edge of which is thickened, coloured brown, very sharp. In the right wing, but not in the 1°^’ there is a little plate, as transparent as talc, surround® by nervures, and called the speculum. In Ephippi'J11' vitium, a member of this same family, we have a curio11-
32 1 Zeitschrift fur wissenschaft. Zoolog.’ B. xvii. 1867, s. 117.
33 AVeatwood, ‘ Modern Class, of Insects,’ vol. i. p. 440.
Chap. X.
ORTHOPTERA.
355
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.”34
We thus see that the musical apparatus is more differentiated or specialised in the Locustid®, which include I believe the most powerful performers in t'le Order, than in the Achctidse, in which both wing- covers have the same structure and the same function.35 dj&ndois, however, detected in one ot the Locustidse, Namely in Oecticus, a short and narrow row ot small
si Westwood, ‘ Modern Class, of Insects,’ vol. i. p. 453. 35 Landois, ibid. s. 121, 122.
350
SEXUAL SELECTION.
Part II-
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 rudi- mentary structure on the under side of the right wing- cover in Phasgonura viridissima. Hence we may with confidence infer that the Locustidse are descended from a form, in which, as in the existing Achetidfe, both wing-covers had serrated nervures on the under surface, and could be indifferently used as the bow ; but that in the Locustidse the two wing-covers gradually became differentiated and perfected, on the principle of the divi- sion of labour, the one to act exclusively as the bow and the other as the fiddle. By what steps the more simple apparatus in the Aehetidm originated, we do not know, hut it is probable that the basal portions of tlie wing- covers overlapped each other formerly as at present, and that the friction of the nervures produced a grating sound, as I find is now the case with the wing-covers of the females.36 A grating sound thus occasionally and accidentally 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 fitting variations in the roughness of the nervures bavins: been continually preserved.
In the last and third Family, namely the Acridiid# or grasshoppers, the stridulation is produced in a very different manner, and is not so shrill, according to Pr' Scudder, as in the preceding Families. The inner sur- face of the femur (fig. 13, r ) is furnished with a longi- tudinal row of minute, elegant, lancet-shaped, elastic teeth, from 85 to 93 in number ;37 and these are scraps
315 Mr. Walsh also informs me that he lias noticed that the female of the Platyphyllum concavum, “ when captured makes a feeble grating “ noise by shuffling her wing-covers together.”
37 Landois, ibid. s. 11:1.
Chap. x.
ORTHOPTERA.
357
Fig. 13.
Hind-leg of Stenobothrus pratorura r, the Btridulattng ridge ; lower figure, the teeth, forming the ridge, much magnified (from Ijandois).
across the sharp, projecting nervures on the wing-covers, 'vhich are thus made to vibrate and resound. Harris3 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 de- signed to receive it,
“ and then draws the leg “briskly up and down.
“He does not play both “ Addles together, but al- “ ternately first upon one “ and then on the other.” la many species, the base °f the abdomen is hollowed out into a great cavity "'hich is believed to act as a resounding board. In hneumora (fig. 14), a S. African genus belonging to mis same family, we meet with a new and remarkable Modification : in the males a small notched ridge pro- jects obliquely from each side of the abdomen, against "hich the hind femora are rubbed.39 As the male is burnished with wings, the female being wingless, it is Mruarkable that the thighs are not rubbed in the usual Manner against the wing-covers ; but this may perhaps accounted for by the unusually small size of the hind- W- I have not been able to examine the inner 8Mface of the thighs, which, judging from analogy, "‘ould be finely serrated. The species of Pneumora We been more profoundly modified lor the sake of 'Hidulatiou than any other orthopterous insect ; for
33 1 Insects of New England,’ 1812, p. 133.
39 Westwood, ‘Modern Classification,’ vol. i. p. 462.
358
SEXUAL SELECTION.
Part Il-
ia the male the whole body has been converted into a musical instrument, being distended with air, like a great pellucid bladder, so as to increase the resonance. Mr. Trimen informs me that at the Cape of Good Hope these insects make a wonderful noise during the night.
Fig. 14. Pneumora (from specimens in the British Museum). Upper figure, m^e’ lower figure, female.
There is one exception to the rule that the femal^ in these three Families are destitute of an efficie11 musical apparatus ; for both sexes of Ephippiger (f0 custidie) are said40 to be thus provided. This case virf
40 Westwood, ibid. vol. i. p. 453.
CiUr. X.
ORTHOPTERA.
359
be compared with that of the reindeer, in which species alone both sexes possess horns. Although the female orthoptera are thus almost invariably mute, yet Landois41 found rudiments of the stridulating organs on the fe- mora of the female Acridiidse, and sirni lar rudiments on the Under surface of the wing-covers ot the female Achetidse ; but he failed to find any rudiments in the females of Decticus, one of the Locustid®. In the Homoptera the mute females of Cicada have the proper musical apparatus in an undeveloped state; and we shall here- after meet in other divisions ot the animal kingdom with innumerable instances of structures proper to the male being present in a rudimentary condition in the female. Such cases appear at first sight to indicate that both sexes were pri mordially constructed in the same manner, but that certain organs were subsequently lost by the females. It is, however, a more probable view, as pre- viously explained, that the organs in question were acquired by the males and partially transferred to the females.
Landois has observed another interesting fact, namely that in the females of the Acridiid®, the stridulating teetli on the femora remain throughout life in the same condition in which they first appear in both sexes during the larval state. In the males, on the other- band "they become fully developed and acquire their perfect structure at the last moult, when the insect is
feature and ready to breed.
From the facts now given, we see that the means by which the males produce their sounds are extremely diversified in the Orthoptera, and arc altogether dif- ferent from those employed by the Homoptera. But throughout the animal kingdom we incessantly find the
O
41 Landois, ibid. s. 115, 116, 120, 122.
360
SEXUAL SELECTION.
Part II-
same object gained by the most diversified means; this being due to the whole organisation undergoing in the course ot ages multifarious changes; and as part alter part varies, different variations are taken advantage of for the same general purpose. The diversification of the means for producing sound in the three families of the Oi thoptera and in the Homoptera, impresses the mmd with the high importance of these structures to the males, for the sake ot calling or alluring the females. ^ ® need feel no surprise at the amount of modification which the Orthoptera have undergone in this respect, as we now know, from Dr. Scudder’s remarkable discovery,1' 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 “ tlj<; well-known tympanum or stridulating apparatus “ of the male Locust him.” This insect, though in most respects related to the Neuroptera, appears to connect, as is so often the case with very ancient forms, the two Orders of the Neuroptera and Orthoptera which are now generally ranked as quite distinct.
^ I have but little more to say on the Orthoptera- Some of the species are very pugnacious: when two male field-crickets ( Gryllus campestris ) are confined together, they fight till one kills the other; aud the species ol Mantis are described as manoeuvring 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.43 With respect to colour, some exotic locusts are beautifully orna- mented ; the posterior wings being marked with red,
p * ransact- Ent. Soc.’ 3rd series, vol. ii. p Journal of Proceedings, 3 ^Westwood, ‘Modern Class, of Insects,’ vol. i. p. 427; for crickets,
Chap. X.
NE U IiOPTIfi LiA.
361
blue, and black; but as throughout the Order the two sexes rarely differ much in colour, it is doubtful whether they owe these bright tints to sexual selection. Conspicuous colours may be of use to these insects as a protection, on the principle to be explained in the next chapter, by giving notice to their enemies that they are unpalatable. Thus it has been observed44 that an Indian brightly-coloured locust was invariably rejected when offered to birds and lizards. Some cases, however, of sexual differences in colour in this Order are known. The male of an American cricket41 is de- scribed as being as white as ivory, whilst the female varies from almost white to greenish-yellow or dusky. Mr. Walsh informs me that the adult male of Spectrum femoratum (ono of the Phasmidse) “ is of a shining “ brownish -yellow colour; the adult female being of ‘‘a dull, opaque, cinereous-brown; the young of both “ sexes being green.” Lastly, I may mention that the male of one curious kind of cricket 40 is furnished with “ a long membranous appendage, which falls over the “ face like a veil ; ” but whether this serves as an orna- ment is not known.
Order, Neuroptera. — Little need here be said, except in regard to colour. Iu the Ephemeral® the sexes often differ slightly in their obscure tints;47 but it is Hot probable that the males are thus rendered attrac- tive to the females. The Libel lulidse or dragon-flies me ornamented with splendid green, blue, yellow, and
14 Mr. Cli. Horne, in ‘ Proc. Ent. Soc.’ May 3, 1809, p. xii.
4o Tlie Oecauthus nivalis. Harris, 1 Insects of New England,’ 1 S42, P. 124.
H Platyblenmus : Westwood, ‘ Modern. Class.’ vol. i. p. 447.
47 B. D. Walsh, the Pseudo-neuroptera of Illinois, in ‘Proc. Ent. Soc. of Philadelphia,’ 18G2, p. 3G1.
3B2
SEXUAL SELECTION.
Part II.
vermilion metallic tints; and the sexes often differ. Thus, the males of some of the Agrionidae, as Prof. Westwood remarks/8 “are of a rich blue with black “ wings, whilst the females are line green with colourless “wings.” Put in Agrion Ramburii these colours are exactly reversed in the two sexes.49 In the extensive N. American genus of Hetserina, the males alone have a beautiful carmine spot at the base of each wing. In Anax junius the basal part of the abdomen in the male is a vivid ultra-marine blue, and in the female grass- green. In the allied genus Gomphus, on the other hand, and in some other genera, the sexes differ but little in colour. Throughout the animal kingdom, similar cases of the sexes of closely-allied forms either differing greatly, or very little, or not at all, are of frequent occurrence. Although with many Libellulidse there is so wide a difference in colour between the sexes, it is often difficult to say which is the most brilliant; and the ordinary coloration of the two sexes is exactly reversed, as we have just seen, in one species of Agrion. It is not probable that their colours in any case have been gained as a protection. As Mr. MacLachlan, who has closely attended to this family, writes to me, dragon- flies— the tyrants of the insect-world — are the least liable of any insect to be attacked by birds or other enemies. He believes that their bright colours serve as a sexual attraction. It deserves notice, as bearing on this subject, that certain dragon-flies appear to be attracted by particular colours : Mr. Patterson observed30 that the species of Agrionidm, of which the males are blue, settled in numbers on the blue float of a fishing
48 ‘ Modern Class.’ vol. ii. p. 37.
49 Walsh, ibid. p. 881. I am indebted to this naturalist for tbo folio-wing- facts on Hetserina, Anas, and Gomphus.
60 1 Transact. Ent. Soc.’ vol. i. 1836, p. lxxxi.
Chap. X.
NEUROPTEEA.
line ; whilst two other species were attracted by shining white colours.
It is an interesting fact, first observed by Sclielver, that the males, in several genera belonging to two sub- families, when they first emerge from the pupal state are coloured exactly like the females ; but that their bodies in a short time assume a conspicuous milky-blue tint, owing to the exudation of a kind of oil, soluble in ether and alcohol. Mr. MacLaehlau believes that in the male of Libellula depressa this change of colour does not occur until nearly a fortnight after the metamorphosis, when the sexes are ready to pair.
Certain species of Neurothemis present, according to Brauer51 a curious case of dimorphism, some of the females having their wings netted in the usual manner ; whilst other females have them “ very richly netted as in “ the males of the same species.” Brauer “ explains “ the phenomenon on Darwinian principles by the “ supposition that the close netting of the veins is a “ secondary sexual character in the males.” This latter character is generally developed in the males alone, but being, like every other masculine character, latent in the female, is occasionally developed in them. We have here an illustration of the manner in which the two sexes of many animals have probably come to resemble each other, namely by variations first appear- ing in the males, being preserved in them, and then transmitted to and developed in the females ; but in this particular genus a complete transference is occa- sionally and abruptly effected. Mr. MacLachlan in- forms me of another case of dimorphism occurring in several species of Agrion in which a certain number ot individuals are found ot an orange coloui, and these are
51 See abstract in the ‘Zoological Becord ’ for 18G7, p. 450.
364
SEXUAL SELECTION.
Part II.
invariably females. This is probably a case of reversion, lor in the true Libellulse, when the sexes differ in colour, the females are always orange or yellow, so that supposing Agrion to be descended from some pri- mordial form having the characteristic sexual colours of the typical Libelluke, it would not be surprising that a tendency to vary in this manner should occur in the females alone.
Although many dragon-flies are such large, powerful, and fierce insects, the males have not been observed by Mr. MacLachlan to fight together, except, as he believes, in the case of some of the smaller species of Agrion. In another very distinct group in this Order, namely in 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.” 52
Order, Hymenojotera.— That inimitable observer, M. Fabre,’J in describing the habits of Cerceris, a wasp- like insect, remarks that “ fights frequently ensue between the males for the possession of some parti- ‘ cl*lar female, who sits an apparently unconcerned “ beholder of the struggle for supremacy, and when the victory is decided, quietly flies away in company “ with the conqueror.” Westwood 54 says that the males of one of the saw-flies (Tenth rcdiiuc) “ have beeu “ found fighting together, with their mandibles locked.” As M. I’abi'e speaks of the males of Cerceris striving to obtain a particular female, it may be well to bear in
Kirby and Spence, ‘ Introduct. to F.utomology,’ vol. ii. 1818, p. 35.
,J See an interesting article, “ Tire Writings of Fubre,” in 1 Nat. Hist. Keview,’ April, 1882, p. 122.
‘Journal of Proc. of Entomolog. Soc.’ Sept. 7th, 18(13, p. 109.
Chap. X.
HYMENOPTERA.
365
mind that insects belonging to this Order have the power of recognising each other after long intervals of time, and are deeply attached, if or instance, Pierre Huber, whose accuracy no one doubts, separated some ants, and when after an interval of four months they met others which had formerly belonged to the same community, they mutually recognised and caressed each other with their antennae. Had they been strangers they would have fought together. Again, when two communities engage in a battle, the ants on the same side in the general confusion sometimes attack each other, but they soon perceive their mistake, and the one ant soothes the other.55
In this Order slight differences in colour, according to sex, are common, but conspicuous differences are rare except in the family of Bees; yet both sexes of certain groups are so brilliantly coloured — for instance m Chrysis, in which vermilion and metallic greens Prevail — that we are tempted to attribute the result to sexual selection. In the Ichneumonidse, according to Hr. Walsh,58 the males are almost universally lighter coloured than the females. On the other hand, in the Tenthredinidue the males are generally darker than the females. In the Siricidm the sexes frequently differ; thus the male of Sirex juvencus is banded with orange, "hi 1st the female is dark purple ; but it is difficult to say which sex is the most ornamented. In Tremex columbm the female is much brighter coloured than the "nile. With ants, as I am informed by Mr. F. Smith, the males of several species are black, the females being testaceous. In the family of Bees, especially in
55 P. Huber, ‘Kecherches sur les Moeurs des Fourmis,’ 1810, p. 150, 165.
56 ‘ Pvoc. Entomolog. Soc. of Philadelphia,’ 18GG, p. 238-239.
366
SEXUAL SELECTION.
Part II.
the solitary species, as I hear from the same distin- guished entomologist, the sexes often differ in colour. The males are generally the brightest, and in Bombus as well as in Apathus, much more variable in colour than the females. In Anthophora retusa the male is of a rich fulvous-brown, whilst the female is quite black: so are the females of several species of Xylocopa, the males being bright yellow. In an Australian bee ( Lest/is bombylans), the female is of an extremely brilliant steel-blue, sometimes tinted with vivid green ; the male being of a bright brassy colour clothed with rich fulvous pubescence. As in this group the females are provided with excellent defensive weapons in their stings, it is not probable that they have come to differ in colour from the males for the sake of protection.
Mutilla Europtm emits a stridulating noise ; and ac- cording to Goureau 57 both sexes have this power. Be 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, on 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, as do some dipterous insects ; but I have not referred to these sounds, as they are not known to be in any way connected with the act of courtship.
Order, Coleoptera (Beetles). — Many beetles are coloured so as to resemble the surfaces which they
57 Quoted by Westwood, ‘Modern Class, of Insects,’ vol. ii. p. 211.
Chap. X.
COLEOPTEEA.
367
habitually frequent. Other species are ornamented with gorgeous metallic tints, — for instance, many Cara- bidte, which lire on the ground and have the power of defending themselves by an intensely acrid secretion, —the splendid diamond-beetles which are protected by an extremely hard covering, — many species of Chry- somela, such as 0. cerealis, a large species beautifully striped with various colours, and in Britain confined to the bare summit of Snowdon, — and a host of other species. These splendid colours, which are often arranged in stripes, spots, crosses and other elegant patterns, can hardly he beneficial, as a protection, except in the case of some flower-feeding species; and we cannot believe that they are purposeless. Hence the suspicion arises, that they serve as a sexual attraction ; but we have no evidence on this head, for the sexes rarely differ in colour. Blind beetles, which cannot of course behold each other’s beauty, never exhibit, as I hear from Mr. Waterhouse, jun., bright colours, though they often have polished coats : but the explanation of their obscurity may he that blind insects inhabit caves and other obscure stations.
Some ' Longicorns, however, especially certain Pri- onidrn, offer an exception to the common rule that the sexes of beetles do not differ in colour. Most of these insects are large and splendidly coloured. 1 he males in the genus Pyrodes,58 as I saw in Mr. Bates collection, are
58 Pyrodes pulcherrimus, in which tlie sexes differ conspicuously, has been described by Mr. Bates in ‘ Transact. Eut. Soc.’ 1809, p. 50. I WiU specify tiro few other cases in which T have heard oi a difference >n colour between the sexes of beetles. Kirby and , Spence (‘ Introduct. to Entomology,’ vol. iii. p. 301) mention a Cantharis, Mcloe, Rhagium, and the Leptura testacea ; the male of tiro latter being testaceous, with a black thorax, and the female ot a dull red all over. These two tatter beetles belong to the Order of Longicorns. Messrs. It. Trimen and Waterhouse, junr., inform mo of two Lamellicorns, viz., a Peri-
36‘S
SEXUAL SELECTION.
Part II.
generally redder but rather duller than the females, the latter being coloured 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 the sexes differ so greatly in colour that they have been ranked as distinct species: in one species both are of a beautiful shining green, but the male has a red thorax. On the whole, as far as I could judge, the females of those Prionidse, in which the sexes differ, are coloured more richly than the males; and this does not accord with the common rule in regard to colour when acquired through sexual selection.
Fig. 15.
trichia and Trichius, the male of the latter being more obscurely coloured than the female. In Tillux i.hmgatiis the male is black, and the female always, as it is believed, of a. dark blue colour with a red thorax. The male, also, of Onnflacna atra , ns I hear from Mr. Walsh, is black, the female (the so-called 0. ruficullis ) having a rufous thorns.
Chalcosoma atlas, Upper figure, male (reduced) ; lower figure, female (nat. size).
chap. X.
COLEOPTERA.
f
i
Copris isidis. (Left-hand figures, males.)
I'ig. 11.
lMianauis faun us.
K'g 18.
Dipelicus canton.
pig. 19.
VOL. T.
Onthophagus ranglfer. enlarged.
370
SEXUAL SELECTION.
Part U-
A most remarkable distinction between the sexes of many beetles is presented by the great horns which rise from the head, thorax, or clypeus of the males; and in some few cases from the under surface of the body. These horns, in the great family of the Lamelli- corns, resemble those of various quadrupeds, such as stags, rhinoceroses, &e., and are wonderful both from their size and diversified shapes. Instead of describing them, I have given figures of the males and females of some of the more remarkable forms. (Figs. 15 to 19.) Tiie females generally exhibit rudiments of the horns in the form of small knobs or ridges; but some are destitute of even a rudiment. On the other hand, the horns are nearly as well developed in the female as in the male of Phanmm lancifer ; and only a little less well developed in the females of some other species of the same genus and of Copris. In the several sub- divisions of the family, the differences in structure of the horns do not run parallel, as I am informed by Mr. Bates, with their more important and characteristic differences ; thus within the same natural section of the genus Onthophagus, there are species which have either a single cephalic horn, or two distinct horns.
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 distin- guished from the females. Mr Walsh59 found that m PhcmxMS carnifex the horns were thrice as long in sonio males as in others. Mr. Bates, after examining above a hundred males of Onthophagus rangifer (fig. 19)> thought that he had at last discovered a species i"
S9 ‘ Proc. Entomolog. Soe. of Philadelphia,’ 1864, p. 228.
Chap. X.
COLEOPTERA.
371
which the horns did not vary ; but further research proved the contrary.
The extraordinary size of the horns, and their widely different structure in closely-allied forms, indicate that they have been formed for some important purpose; hut their excessive variability in the males of the same species leads to the inference that this purpose cannot he of a definite nature. The horns do not show marks of friction, as if used for any ordinary work. Some authors suppose'10 that as the males wander much more than the females, they require horns as a defence against their enemies; but in many eases the horns do not seem well adapted for defence, as they are not sharp. The most obvious conjecture is that they are Used by the males for fighting together; hut they have never been observed to fight; nor could Mr. Hates, after a careful examination of numerous species, find any sufficient evidence in their mutilated or broken condition of their having been thus used. If the males had been habitual fighters, their size would probably have been increased through sexual selection, so as to have exceeded that of the female ; but Mr. Bates, after Comparing the two sexes in above a hundred species of the Copridse, does not find in well-developed individuals any marked difference in this respect. There is, more- over, one beetle, belonging to the same great division of the LameUicorns, namely Lethrus, the males of which are known to fight, but they are not provided with horns, though their mandibles are much larger than those of the female.
The conclusion, which best agrees with the lact oi the horns having been so immensely yet not fixedly developed, — as shewn by their extreme variability in
Kirby and Sponce, ‘ Introduct. Entomolog.’ vol. iii. p. 300.
2 B 2
co
372
SEXUAL SELECTION.
Part li-
the same species and by their extreme diversity in closely-allied species — is that they have been acquired as ornaments. 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 Onitis furcifer (fig. 20) are furnished with singular projections on their anterior femora, and
body, yet in the females a rudiment of a single horn on the head (fig. 21, a), and of a crest (b) on the thorax, are plainly visible. That the slight thoracic crest in the
Fig. 21. Left-band figure, male of Onitis furcifer, viewed laterally. Right-hand figure female. a. Rudiment of cephalic horn. &. Trace of thoracic horn or crest.
female is a rudiment of a projection proper to the male* though entirely absent in the male of this particular species, is clear : for the female of Bubas bison (a form
horns on the upper surface of the
Chap. X.
COLEOPTERA.
373
which comes next to Onitis) lias a similar sliglit crest' on the thorax, and the male has in the same situation a great projection. So again there can be no doubt that the little point (a) on the head of the female Onitis furcifer, as well of the females of two or three allied species, is a rudimentary representative of the cephalic horn, which is common to the males of so many lamel- licorn beetles, as in Phameus, fig. 17. The males indeed of some unnamed beetles in the Rritish Museum, which are believed actually to belong to the genus Onitis, are furnished with a similar horn. The remarkable nature of this case will be best perceived by an illustration : the Ruminant quadrupeds run parallel with the larnel- licorn beetles, in some females possessing horns as large us those of the male, in others having them much smaller, or existing as mere rudiments (though this is Us rare with ruminants as it is common with Lamelli- Corns), or in having none at all. Now if a new species of deer or sheep were discovered with the female bearing distinct rudiments of horns, whilst the head of the male was absolutely smooth, we should have a case like that of Onitis furcifer.
In this case the old belief of rudiments having been created to complete the scheme of nature is so far from bolding good, that all ordinary rules are completely broken through. The view which seems the most pro- bable is that some early progenitor of Onitis acquired, like other Lamellicorns, horns on the head and thorax, and then transferred them, in a rudimentary condition, as with so many existing species, to the female, by whom they have ever since been retained. The subsequent loss of the horns by the male may have resulted through fbe principle of compensation from the development of the projections on the lower surface, whilst the female bag not been thus affected, as she is not furnished with
374
SEXUAL SELECTIONS
Pakt IL
these projections, and consequently has retained the rudiments of tho horns on the upper surface. Although this view is supported by the case of Bledius imme- diately to he given, yet the projections on the lower surface differ greatly in structure and development in the males of the several species of Onitis, and are even rudimentary in some ; nevertheless the upper surface in all these species is quite destitute of horns. As secondary sexual characters are so eminently variable, it is possible that the projections on the lower surface may have been first acquired by some progenitor of Onitis and produced their effect through compensation, and then have been in certain cases almost completely lost.
All the cases hitherto given refer to the Lamelli' corns, but the males of some few other beetles, be- longing to two widely distinct groups, namely, the Curculionidm and Staph y] in idee, are furnished with horns— in the former on tiie lower surface of the body,61 in the latter on the upper surface of the head and thoiax. In the Staphylinidse the horns of the males in the same species are extraordinarily variable, just as we have seen with the Lamellicorns. In Siagoniu®
22. Bledius tauvus, magnified. Beft-liand figure, male ; riglit-band figure, female-
we have a case of dimorphism, for the males can be divided into two sets, differing greatly in the size ot their bodies, and in the development of their horny without any intermediate gradations. In a species of Bledius (fig. 22), also belonging to the Staphvlinid®, male specimens can be found in the same locality, aS
61 Kirby and Spence, ibid. vol. iii. p. 329.
Chap. X.
COLEOPTEEA.
375
Professor Westwood states, “ in which the central horn “ of the thorax is very large, but the horns of the head “ quite rudimental ; and others, in which the thoracic “horn is much shorter, whilst the protuberances on “the head are long.”62 Here, then, we apparently have an instance of compensation of growth, which throws light on the curious case just gi ven of the loss of the upper horns by the males oi Onitis furcffer.
Law of Battle.— Some male beetles, which seem ill fitted for fighting, nevertheless engage in conflicts ■ for the possession of the females. Mr. Wallace 05 saw two males of Leptorhynchus angustatm , a linear beetle with a much elongated rostrum, “fighting lor a female, who “ stood close by busy at her boring. They pushed at “ each other w ith their rostra, and clawed and thumped, “ apparently in the greatest rage.” The smaller male, however, “soon ran away, acknowledging himselt van- quished.” In some few cases the males are well adapted for fighting, by possessing great toothed man- dibles, much larger than those of the females. This is the case with the common stag-beetle {Lucanus cervus), the males of which emerge from the pupal state about a week before the other sex, so that several may often be seen pursuing the same female. At this period they engage in fierce conflicts. When Mr. A. I . Davis64 enclosed two males with one female in a box, the larger male severely pinched the smaller one, until he resigned his pretensions. A friend informs me
62 ‘Modern Classification of Insects,' vol i. p. 172 On the same page there is an account of Siagonium. In the Brit sli Museum I noticed one male specimen of Siagonium m an intermediate condition, so that the dimorphism is not strict.
03 ‘ The Malay Archipelago,’ vol. ii. 1839, p- 270.
M < T*1 r, t nm nlnodnal Magazine,’ vol. i. 1833, p. hee
also on the
conflicts of this species, Kirby and Spence, ibid. vol. iii. p. 314; and tVestwood, ibid. vol. i. p. 1S7.
376
SEXUAL SELECTION.
Part II>
that when a boy he often put the males together to see them fight, and lie noticed that they were much bolder and fiercer than the females, as is well known to be the case with the higher animals. The males would seize hold of his finger, if held in front, but not so the females. With many of the Lucanidae, as well as with the above- mentioned Leptorhynchns, the males are larger and more powerful insects than the females. The two sexes of Lethrus cephalotes (one of the Lamellicoms) inhabit the same burrow ; and the male has larger mandibles than the female. If, during the breeding-season, a strung® male attempts to enter the burrow, he is attacked; the female does not remain passive, but closes the mouth ot the burrow, and encourages her mate by continually pushing him on from behind. The action does not cease until the aggressor is killed or runs awav.65 The two sexes of another lamellicorn beetle, the Ateuch ** cicatrieosus live in pairs, and seem much attached to each other; the male excites the female to roll the balls of dung in which the ova are deposited ; and d she is removed, he becomes much agitated. If the male is removed, the female ceases all work, and a® M. Brulerie06 believes, would remain on the spot until she died.
The great mandibles of the male Lucanidae are ex- tremely variable both in size and structure, and in tliig respect resemble the horns or the head and thorax of many male Lamellicorns and Stapliylinidre. A per- fect series can be formed from the best-provided to the worst-provided or degenerate males. Although the mandibles of the common stag-beetle, and probably of
03 Quoted from Fiselier, in ‘ Diet. Class. d’Hist. Nat.’ tom. x. p. 324- 60 ‘Ann. Soc. Eutomolog. France,’ 1866, as quoted in ‘Journal Travel,’ by A. Murray, 1868, p. 135.
Chap. X.
COLEOPTEKA.
377
many other species, are used as efficient weapons for fighting, it is doubtful whether their great size can thus be accounted for. \\ e have seen that with the Lucanus da- phus of N. America they are used for seizing the female. As they are so conspicuous and so ele- gantly branched, the suspicion has sometimes crossed my mind that they may be serviceable to the males as an ornament, in the same manner as the horns on the head and thorax of the various above described species. The male Chiasognatlms grantii of S.
Chile — a splendid beetle belong- ing to the same family — has enor- mously-developed mandibles (fig.
23) ; lie is bold and pugnacious ;
When threatened on any side lie faces round, opening his great jaws, and at the same time stridu- lating loudly ; hut the mandibles were not strong enough to pinch my finger so as to cause actual pain.
Sexual selection, which implies the possession of considerable per- ceptive powers and of strong pas- sions, seems to have been more effective with the Lamellicorns than with any other family of the Coleoptera or beetles. With some species tlie males are provided with weapons for fight- ing ; some live in pairs and show mutual affection ;
Fig. 23. ChmsogTMtlius grantii, reduced. U pper figure, male ; lower figure, female.
378
SEXUAL SELECTION.
Pakt li-
man y have the power of stridnlating when excited ; many are furnished with the most extraordinary horns, appa* rently for the sake of ornament ; some which are diurnal in their habits are gorgeously coloured ; and, lastly* several of the largest beetles in the world belong to this family, which was placed by Linnseus and Fabricius at the head of the Order of the Coleoptera.07
Siridulating organs. — Beetles belonging to many and widely distinct families possess these organs. The sound can sometimes be heard at the distance of several feet or even yards,08 but is not comparable with that produced by the Orthoptera. The part which may be called the rasp generally consists of a narrow slightly- raised surface, crossed by very fine, parallel ribs, some- times so fine as to cause iridescent colours, and having a very elegant appearance under the microscope. I11 some cases, for instance, with Typhceus, it could be plainly seen that extremely minute, bristly, scale-like prominences, which cover the whole surrounding sur- face in approximately parallel lines, give rise to the ribs of the rasp by becoming confluent and straight, and at the same time more prominent and smooth. A hal'd ridge on any adjoining part of the body, which in son>e cases is specially modified for the purpose, serves as the scraper for the rasp. The scraper is rapidly moved across the rasp, or conversely the rasp across the scraper.
These organs are situated in widely different posi- tions. In the carrion-beetles (Necrophorus) two parallel rasps (r, fig. 24) stand on the dorsal surface of the fiffb abdominal segment, each rasp being crossed, as described by Landois,69 by from 12(3 to 140 fine ribs. These
6? Westwood, * Modern Class.’ vol. i. p. 184. j.
r>s Wollaston, On certain musical Curculionidse, ‘Annals and Mag- 0 Nat. Hist.’ vol. vi. 1860, p. 14. sn ‘ Zeitsohrift fur wiss. Zoolog.’ B. xvii. 1807, s. 127.
(lHAP. X.
coleoptera.
379
ribs are scraped by tlie posterior margins of the elytra, a small portion of which projects beyond the general out- line. In many Crioceridte, and in Clyihra k-punctata
Fig. 24. Necropliorus (from Landois). r. The two rasps. Left-hand figure, part of the rasp highly magnified.
(one of the Chrysomeliilse), and in some Tenebrionidae, &c\,70 the rasp is seated on the dorsal apex of the abdo- men, on the pygidium or pro-pygidium, and is scraped as above 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.71 In certain Curculionidae and Cara- bidte,72 the parts are completely reversed in position,
70 I urn greatly indebted to Mr. G. K. Crotch for haying sent me hunierous prepared specimens of various beetles bdongimr to these three families and others, ns well as for valuable information of nil kinds. He believes that the power of stimulation in the Clyihra has not been pre- viously observed. lam also much indebted to Mr. E. IV. Jnnson, for information and specimens. I may add that my son, Mr. F. Darwin, buds that Dermestes murinns stridulatcs, hut he searched in vain for the apparatus. Scoiytus has lately been described by Dr. Chapman as a stridulator, in the * Entomologist’s Monthly Magazine,’ vul. vi. p. 130.
71 Scliiodte, translated in ’Annals and Mag. ot Nat. Hist. vol. xx. f&67, p. 37.
72 Westring has described (Kroyer, ‘Naturbist. lidskrilt, B. ii. 1848- 10, p, syl) the stridulating organs in these two, as well as in other families. In the Carabidar I have examined Elaphrui uliginoews and J'b-thisa multipunctata, sent to me by Mr. Crotch. In l.lethisa the transverse ridges on the furrowed border of tlie abdominal segment do n«t come interplay, as far as I could judge, in scraping tlie rasps on tho elytra.
380
SEXUAL SELECTION.
Part II-
for tlie 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 he.rma.nni (one of Dytiscidse or water-beetles) a strong ridge runs parallel and near to the sutural margin of the elytra, and is crossed by ribs, coarse in the middle part, but becoming gradually finer at both ends, especially at the upper end ; when this insect is held under water or in the air, a stridulating noise is produced by scraping the extreme horny margin of the abdomen against the rasp. In a great number of long-homed beetles (Longicornia) the organs are alto- gether differently situated, the rasp being on the meso- thorax, which is rubbed against the pro-thorax ; Landois counted 238 very line ribs on the rasp of Ceraniby <C heron.
Many Lamellicorns have the power of stridulating, and the organs differ greatly in position. Some species stridulate very loudly, so that when Mr. F. Smith caught a Trox sabu - losus, a gamekeeper who stood by thought that he had caught a mouse ; but I failed to discover the proper organs in this beetle. In Geotrupes and Typhous a narrow ridge runs obliquely across (r, fig- 25) the coxa of each hind-leg, having in G. stercorarius 84 ribs, which are scraped by a specially projecting part of one of the abdo-
Fig, 25. Hind-leg of Geotrupes . ^ . t i i «r
stercorarius (from Landois). LHlHiil SGglUGIltS. Ill til 6 HCtU }
r. Rasp, c. coxa. /. Femur, allied Copris lunar is, an excessively
t. Tibia, tr. Tarsi. 7. ,
narrow tine rasp runs along sutural margin of the elytra, with another short rasp near the basal outer margin ; but in some other Coprin1
Chap. X.
COLEOPTERA.
381
the rasp is seated, according to Leconte,73 on the dorsal sin-face of the abdomen. In Oryctes it is seated on the pro-pygidium, and in some other Dynastini, according to the same entomologist, on the under surface of the elytra. Lastly, Westring states that in Omaloplia Itrun- nea the rasp is placed on the pro-sternum, and the scraper on the meta-sternum, the parts thus occupying the under surface of the body, instead of the upper surface as in the Longicorns.
We thus see that the stridulating organs in the dif- ferent coleopterous families are wonderfully diversified in position, but not much in structure. Within the same family some species are provided with these organs, and some are quite destitute of them. This diversity is intelligible, if we suppose that originally various species made a shuffling or hissing noise by the rubbing together of the hard and rough parts of their bodies which were in contact ; and that from the noise thus produced being in some way useful, the rough surfaces were gradually developed into regular stri- dulating organs. Some beetles as they move, now produce, either intentionally or unintentionally, a shuf- fling noise, without possessing any proper organs for the purpose. Mr. Wallace informs me that the Euchirus hngimanus (a Lamellicorn, with the anterior legs won- derfully elongated in the male) “ makes, whilst moving, “ a low hissing sound by the protrusion and contraction “ of the abdomen ; and when seized it produces a “grating sound by rubbing its liind-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
73 I am indebted to Mr. Walsh, of Illinois, for having sent me ^tracts from Leconte’s ‘Introduction to Entomology,’ p. 101, 143.
382
SEXUAL SELECTION.
Pakt II-
sound by rubbing the shagreened surface of the femur against the granulated margin of the corresponding elytron; but I could not here detect any proper rasp; nor is it likely that I could have overlooked it in so large an insect. After examining Cychrus and reading what Westring has written in his two papers about this beetle, it seems very doubtful whether it possesses any true rasp, though it has the power of emitting a sound.
From the analogy of the Orthoptera and Homoptera, I expected to find that the stridulating organs in the Coleoptera differed according to sex ; but Landois, who has carefully examined several species, observed no such difference ; nor did Westring ; nor did Mr. Gr. 11- Crotch in preparing the numerous specimens which he had the kindness to send me for examination. AnJ' slight sexual difference, however, would be difficult to detect, on account of the great variability of these organs- Thus in the first pair of the Necrophorus liumator and of the Pebbius which I examined, the rasp was consider' ably larger in the male than in the female; but not so with succeeding specimens. In Qeotrupes siercorariu3 the rasp appeared to me thicker, opaquer, and more prominent in three males than in the same number ot females; consequently my son, Mr. F. Darwin, in order to discover whether the sexes differed in their power of stridulating, collected 57 living specimens, which he separated into two lots, according as they made, whe» held in the same manner, a greater or lesser noise. H13 then examined their sexes, but found that the male5 were very nearly in the same proportion to the females in both lots. Mr. F. Smith has kept alive numerous specimens of Mononychus pseudaeori (Curculiouidse), and is satisfied that both sexes stridulate, and apparently i° an equal degree.
Nevertheless the power of stridulating is certainly 11
Chap. X.
COLEOPTEltA.
383
sexual character in some few Coleoptera. Mr. Crotch has discovered that the males alone of two species of Heliopathes (Tenebrionidse) possess stridnlating organs. I examined five males of U. giblus, and in all these there was a well-developed rasp, partially divided into two, on the dorsal surface of the terminal abdominal segment; whilst in the same number of females there Was not even a rudiment of the rasp, the membrane of this segment being transparent and much thinner than m the male. In H. crilratostriaius the male has a similar rasp, excepting that it is not partially divided into two portions, and the female is completely desti- tute of this organ; but in addition the male 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 line ribs, parallel to and re- sembling those on the abdominal rasp ; whether these ridges serve as an independent rasp, or as a scraper for the abdominal rasp, I could not decide: the female exhibits no trace of this latter structure.
Again, in three species of the Lamellicorn genus Oryctes, we have a nearly parallel case. In the females of 0. gnjphus and nasicornis the ribs on the rasp of the pfo-pvgidium are less continuous and loss distinct than m 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 °r are represented by excessively line down in the males. It should be noticed that in all Coleoptera the effective Part of the rasp is destitute of hairs. In 0. senagal- e>isis the difference between the sexes is more strongly parked, and this is best seen when the proper segment ls cleaned and viewed as a transparent object. In the female the whole surface is covered with little separate Cl'ests, bearing spines ; whilst in the male these crests
884
SEXUAL SELECTION.
Part II-
become, in proceeding towards the apex, 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, when the abdomen of a softened specimen is pushed back- wards and forwards, a slight grating or stridulating sound can be produced.
In the case of the Heliopathes and Oryctes there can hardly be a doubt that the males stridulate in order to call or to excite the females ; but with most beetles the stridulation apparently serves both sexes as a mutual call. This view is not rendered improbable from beetles stridulating under various emotions ; we know that birds use their voices for many purposes besides singing to their mates. The great Chiasognathus stridulates h1 anger or defiance ; many species do the same from dis- tress or fear, when held so that they cannot escape ! Messrs. Wollaston and Crotch were able, by striking the hollow stems of trees in the Canary Islands, to dis- cover the presence of beetles belonging -to the genus Acalles by their stridulation. Lastly the male AteU- chus stridulates to encourage the female in her work and from distress when she is removed/1 Some natu- ralists believe that beetles make this noise to frighten away their enemies ; but I cannot think that the quadru- peds and birds which are able to devour the larg®r beetles with their extremely hard coats, would be fright' ened by so slight a grating sound. The belief that the stridulation serves as a sexual call is supported by the fact that death-ticks (Anolium tessdlatuni ) are well known to auswer eacli other’s ticking, or, as I have
74 M. P. de la Brulerie, as quoted in 1 Journal of Travel,’ A. Murr®)’ vol. i. 1808, p. 13o.
Chap. X.
COLEOPTERA.
385
myself observed, a tapping noise artificially made ; and Mr. Doubleday informs me that he has twice or thrice observed a female ticking,75 and in the course of an hour or two has found her united with a male, and on one Occasion surrounded by several males. Finally, it seems probable that the two sexes of many kinds of beetles "ere at first enabled to find each other by the slight shuffling noise produced by the rubbing together of the adjoining parts of their hard bodies ; and that as the males or females which made the greatest noise suc- ceeded best in finding partners, the rugosities on various parts of their bodies were gradually developed by means of sexual selection into true stridulatiug organs.
75 Mr. Doubleday informs mo that “the noise is produced by the “ insect raising itself on its legs as high as it can, and then striking its ' thorax five or six times, in rapid succession, against the substance upon which it is sitting.” For references on this subject see Landois, Zeitsohrift fur wisson. Zoolog.’ B. xvii. s. 131. Olivier says (as quoted “V Kirby and Spence, ‘Inlroduct.’ vol. ii. p. 395) that the female of 1'imeliu striata produces a rather loud sound by striking her abdomen flgaiust any hard substance, “ and that the male, obedient to this call, 11 soon attends her and they pair.”
SEXUAL SELECTION.
Part #•
386
CHAPTER XI.
Insects, continued. — Order Lepidopteea.
Courtship of butterflies — Battles — Ticking noise — Colours coni' mon to both, sexes, or more brilliant in the males — Examples-' Not due to the direct action of the conditions of life — Colours adapted for protection — Colours of moths — Display — Per- ceptive powers of the Lepidoptera — Variability — Causes of the difference in colour between the males and females — Mimickry, female butterflies more brilliantly coloured than the males-' Bright colours of caterpillars — Summary and concluding re- marks on the secondary sexual characters of insects — Birds and iusects compared.
In this great Order the most interesting point for us is the difference in colour between the sexes of the sai»e species, and between the distinct species of the sai»e genus. Nearly the whole of the following chapter will he devoted to this subject ; but I will first make a fe'v remarks on one or two other points. Several males run/ often be seen pursuing and crowding round the san>e female. Their courtship appears to be a prolonged affair for I hare frequently watched one or more males pirouet- ting round a female until I became tired, without seeing the end of the courtship. Although butterflies are such weak and fragile creatures, they are pugnacious, and a» 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 battle5
1 Apatura Iris : •' The Entomologist’s Weekly Intelligencer,' IS59’
p. 1SU. For the Bornean Butterflies see C. Collingwood, ‘Gambles0*
a Naturalist,’ 1868, p. 183.
Chap. XI.
BUTTERFLIES AND MOTHS.
387
between the butterflies of Borneo says, They whirl “ round each other with the greatest rapidity, and appear “ to he incited by the greatest ferocity.” One case is known of a butterfly, namely the Ageronia feronia, which makes a noise like that produced by a toothed "heel passing under a spring catch, and which could be heard at the distance of several yards. At Bio de Janeiro this sound was noticed by me, only when two were chasing each other in an irregular course, so that it is probably made during the courtship of the sexes ; but I neglected to attend to this point.2
Every one has admired the extreme beauty of many butterflies and of some moths ; and we are led to ask, how has this beauty been acquired ? Have their colours and diversified patterns simply resulted from the direct action of the physical conditions to which these insects have been exposed, without any benefit being thus de- rived? Or have successive variations been accumulated and determined either as a protection or for some un- known purpose, or that one sex might be rendered attractive to the other ? And, again, what is the mean- ing of the colours being widely different in the males and females of certain species, and alike in the two sexes of other species? Before attempting to answer these questions a body of facts must be given.
With most of our English butterflies, both those which are beautiful, such as the admiral, peacock, and painted lady (Vanessas), and those which are plain-coloured, 8Uch as the meadow-browns (Hipparchiae), the sexes are alike. This is also the case with the magnificent lieliconidas and Dana idle of the tropics. But in certain
2 See my ‘Journal of Researches,’ 1815, p. 33. Mr. Doubleday lias 'ktected (‘ Proc. Eut. Soc.’ March 3rd, 1845, p. 123) a peculiar mem- llranou3 sac at the base of the front wings, which is probably cou- nted with the production of the sound.
2 c 2
388
SEXUAL SELECTION.
Part II.
other tropical groups, and with some of our English butterflies, as the purple emperor, orange-tip, &c. (Apa- turn Iris and Anfhocharis cardamines), the sexes differ either greatly or slightly iu colour. No language suffices to describe the splendour of the males of some tropical species. Even within the same genus we often find spe- cies presenting an extraordinary difference between the sexes, whilst others have their sexes closely alike. Thus in the South American genus Epicalia, Mr. Bates, to whom I am much indebted for most of the following facts and for looking over this whole discussion, informs me that he knows twelve species, the two sexes of which haunt the same stations (and this is not always the case with butterflies), and therefore cannot have been dif- ferently affected by external conditions.15 In nine ot these species the males rank amongst the most brilliant of all butterflies, and differ so greatly from the compa- ratively 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 likewise resemble both sexes in several allied genera* found in various parts of the world. Hence in accord- ance with the descent-theory we may infer that the»t! nine species, and probably all the others of the genu4* are descended from an ancestral form which was coloured iu nearly the same manner. In the tenth species th0 female still retains the same general colouring, hut the male resembles her, so that he is coloured in a mud1 less gaudy and contrasted manner than the males of the previous species. In the eleventh and twelfth species* the females depart from the type of colouring wbid1
s See also Mr. Bates’ paper in 1 Proc. Ent. Soc. of Philadelpl*1^ 1S05, p. 206. Also Mr. Wallace on the same subject, in regal'1! Diadema, in 1 Transact. Entomolog. Soc. of London,’ 1&69, p. 27S.
Chap. XI.
BUTTERFLIES AND MOTHS.
389
is usual with their sex in this genus, for they are gaily decorated in nearly the same manner as the males, but in a somewhat less degree. Hence in these two species the bright colours of the males seem to have been trans- ferred to the females; whilst the male of the tenth species has either retained or recovered the plain colours of the female as well as of the parent-form of the genus ; the two sexes being thus rendered in both cases, though in an opposite manner, nearly alike. In the allied genus Eubagis, both sexes of some of the species are plain-coloured and nearly alike ; whilst with the greater number the males are decorated with beautiful metallic tints, in a diversified manner, and differ much from their females. The females through- out the genus retain the same general style of colouring, so that they commonly resemble each other much more closely than they resemble their own proper males.
In the genus Papilio, all the species of the iEneas group are remarkable for their conspicuous and strongly contrasted colours, and they illustrate the frequent ten- dency 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 a little or very much more superbly coloured than the females. The genus Junonia allied to our Yanessse offers a nearly parallel case, for although the sexes of most of the species resemble each other and are desti- tute of rich colours, yet in certain species, as in J. oenone, the male is rather more brightly coloured than the female, and in a few (for instance J. andremiaja) the male is so different from the female that he might be mistaken for an entirely distinct species.
Another striking case was pointed out to me in the British museum by Mr. A. Butler, namely one of the Tropical American Theche, in which both sexes
390
SEXUAL SELECTION.
Part II*
are nearly alike and wonderfully splendid ; in another, the male is coloured in a similarly gorgeous manner, whilst the whole upper surface of the female is of a dull uniform brown. Our common little English blue butter- flies of the genus Lycmna, illustrate the various differ- ences in colour between the sexes, almost as well, though not in so striking a manner, as the above exotic genera. In Lycmna agestis both sexes have wings of a brown colour, bordered with small ocellated orange spots, and are consequently alike. In L. cegon the wings of the male are of a fine blue, bordered with black; whilst the wings of the female are brown, with a similar border, and closely resemble those of L. agestis- Lastly, in L. anon both sexes are of a bine colour and nearly alike, 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 closely alike.
I have given the foregoing cases in some detail in order to shew, in the first place, that w hen the sexes ot butterflies differ, the male as a general rule is the most beautiful, and departs most from the usual type of colour' ing of the group to which the species belongs. Hence in most groups the females of the several species resemble each other much more closely than do the males. In some exceptional cases, however, to which I shall here- after allude, the females are coloured more splendidly than the males. In the second place these cases have been given to bring clearly before the mind that within the same genus, the two sexes frequently present every gradation from no difference in colour to so great a dif- ference that it was long before the two were placed by entomologists in the same genus. In the third place, we have seen that w'hen the sexes nearly resemble each other, this apparently may be due either to the
Chap. XI.
BUTTERFLIES AND MOTHS.
391
male having transferred, his colours to the female, or to the male having retained, or perhaps reco- vered, the primordial colours of the genus to which the species belongs. It also deserves notice that in those groups in which the sexes present any difference of colour, the females usually resemble the males to a cer- tain extent, so that when the males are beautiful to an extraordinary degree, the females almost invariably ex- hibit some degree of beauty. From the numerous 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, whatever they may be, which have determined the brilliant colouring of the males alone of some species, and ol both sexes in a moie or less equal degree of other species, have generally been the same.
As so many gorgeous butterflies inhabit the tropics, it has often been supposed that they owe their colours to the great heat and moisture of these zones ; but Mr. Bates 4 has shewn 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-coloured males and plain-coloured females of the same species inhabit the same district, feed on the same food, and follow exactly the same habits of life. Even when the sexes resemble each other, we can hardly believe that their brilliant and beautifully-arranged colours are the purposeless result of the nature of the tissues, and the action of the surrounding conditions.
With animals of all kinds, whenever colour has been modified for some special purpose, this has been, as far
4 ‘ The Naturalist on the Amazons,’ vol. i. 1863, p. 19.
392
SEXUAL SELECTION.
Pakt II.
as we can judge, either for protection or as an attraction between the sexes. With many species of butterflies the upper surfaces of the wings are obscurely coloured, and this in all probability leads to their escaping ob- servation and danger. But butterflies when at rest would bo particularly liable to be attacked by their enemies; and almost all the kinds when resting raise their wings vertically over their backs, so that the lower sides alone are exposed to view. Hence it is this side which in many cases is obviously coloured so as to imitate the surfaces on which these insects commonly rest. Dr. Rossler, I believe, first noticed the similarity of the closed wings of certain Van ess* 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. Wallace5 of a common Indian and Sumatran butterfly (Kallima), which disappears like magic when it settles in a bush ; for it hides its head and antennae between its closed wings, and these in form, colour, and veining cannot be distinguished from a withered leaf together with the footstalk. In some other cases the lower surfaces of the wings are brilliantly coloured, and yet are protective ; thus in Thecla rubi the wings when closed are of an emerald green and re- semble the young leaves of the bramble, on which this butterfly in the spring may often be seen seated.
Although the obscure tints of the upper or under surface of many butterflies no doubt serve to conceal them, yet we cannot possibly extend this view to the brilliant and conspicuous colours of many kinds, such as our admiral and peacock Vanessas, our white
Sec the interesting article in the < Westminster Review,’ Julv, 1867, p. 10. A woodcut of the Kallima is given by Mr. Wallace in Hard- wieke’s ‘ Science Gossip,’ Sept. 1867, p. 196.
Cjiap. XI.
BUTTERFLIES AND MOTHS.
393
cabbage-butterflies (Pieris), or the great swallow-tail Papilio which haunts the open fens — for these butter- flies are thus rendered risible to every living creature. With these species both sexes are alike ; but iu the common brimstone butterfly (Goneptcryx rhamni ), the male is of an intense yellow, whilst the female is much paler; and in the orange-tip ( Anthocharis ccirdamines) the males alone have the bright orange tips to their wines. In these cases the males and females are equally conspicuous, and it is not credible that their difference in colour stands in any relation to ordinary protection. Nevertheless it is possible that the con- spicuous colours of many species may be in an indirect manner beneficial, as will hereafter be explained, by leading their enemies at once to recognise them as unpalatable. Even in this case it does not certainly follow that their bright colours and beautiful patterns were acquired for this special purpose. In some other remarkable cases, beauty has been gained for the sake of protection, 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.
The female of our orange-tip buttterfly, above re- ferred to, and of an American species ( Anth . genutia) probably shew us, as Mr. Walsh has remarked to me, the primordial colours of the parent - species of the genus ; for both sexes of four or five widely -distributed species are coloured in nearly the same manner. We may infer here, as in several previous cases, that it is the males of Anth. cardamines and genutia which have departed from the usual type of colouring of their genus. In the Anth. sara from California, the orange-tips have become partially developed in the female ; for her wings are tipped with reddish-orange, but paler than in the
394
SEXUAL SELECTIONS
Part II.
male, and slightly different in some other respects. In an allied Indian form, the Iphias glaueippe, the orange- tips are fully developed in both sexes. In this Iphias the under surface of the wings marvellously resembles, as pointed out to me by Mr. A. Butler, a pale-coloured leaf ; and in our English orange-tip, the under surface resembles the flower-head of the wild parsley, on which it may be seen going to rest at night.6 The same reasoning power which compels us to believe that the lower surfaces have here been coloured for the sake of protection, leads us to deny that the wings have been tipped, especially when this character is confined to the maies, with bright orange for the same purpose.
Turning now to Moths : most of these rest motion- less with their wings depressed during the whole or greater part of the day ; and the upper surfaces of their wings are often shaded and coloured in an admirable manner, as Mr. Wallace has remarked, for escaping detection. TV itli most of the Bombycidce and Noc- tuidse,1 when at rest, the front-wings overlap and conceal the hind-wings; so that the latter might be brightly coloured without much risk ; and they are thus coloured in many species of both families. During the act of flight, moths would often be able to escape from their enemies ; nevertheless, as the liind-wings are then fully exposed to view, their bright colours must generally have been acquired at the cost of some little risk. But the following fact shews us how cautious we ought to be in drawing conclu- sions on this head. The common yellow under-wing8
0 See the interesting observations by Mr. T. W. Wood, ‘ The Stu- dent,’ Sept. 1 868, p. 81.
7 Mr- Wallace in ‘Hardwicke’s Science Gossip,’ Sept. 1867, p. 193-
Chap. XI.
BUTTERFLIES AND MOTHS.
395
(Triphaena) often fly about during the day or early evening, and are then conspicuous from the colour of their hind-wings. It would naturally be thought that this would be a source of danger; but Mr. J. Jenner Weir believes that it actually serves them as a means of escape, for birds strike at these brightly coloured and fragile surfaces, instead of at tlie body. For instance, Mr. Weir turned into his aviary a vigorous specimen of Triphaena pronuba, which was instantly pursued by a robin ; but the bird’s attention being caught by the coloured wings, the moth was not captured until after about fifty attempts, and small portions of the wings were repeatedly broken off. He tried the same experi- ment, in the open air, with a T. fimbria and swallow ; but the large size of this moth probably interfered with its capture.8 9 We are thus reminded of a state- ment made by Mr. Wallace,8 namely, that in the Bra- zilian forests and Malayan islands, many common and highly-decorated butterflies are weak flyers, though fur- nished with a broad expanse of wings ; 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 pro- “ portion 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 colours of buttci flies and of some moths are specially arranged for display, whether or not they serve in addition as a protection. Bright
8 See also, on this subject, Mr. Weir’s paper in ‘ Transact. Ent. Soc.’ 1869. p. 23.
9 ‘ Westminster Review,’ July, 18(37, p. 16.
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SEXUAL SELECTION.
Part II.
colours would not be visible during the nigbt; and there can be no doubt that moths, taken as a body, are much less gaily decorated than butterflies, all of which are diurnal in their habits. But the moths in certain families, such as the Zygtenidae, various Sphingidas, Uraniidae, some Arctiidas and Saturnikke, fly about during the day or early evening, and many of these are extremely beautiful, being far more brightly coloured than the strictly nocturnal kinds. A few exceptional cases, however, of brightly-coloured noc- turnal species have been recorded.10
There is evidence of another kind in regard to display. Butterflies, as before remarked, elevate their wings when at rest, and whilst basking in the sunshine often alternately raise anti depress them, thus exposing to full view both surfaces; and although the lower surface is often coloured in an obscure manner as a protection, yet in many species it is as highly coloured as the upper surface, and sometimes in a very different man- ner. In some tropical species the lower surface is even more brilliantly coloured than the upper.11 In one English fritillary, the Argynnis agluia, the lower sur- face alone is ornamented with shining silver discs. Nevertheless, as a general rule, the upper surface, which is probably the most fully exposed, is coloured more brightly and in a more diversified manner than the lower. Hence the lower surface generally affords
10 For instance, Lithosia ; but Prof. Westwood (‘ Modern Class, of Insects,’ vol. ii. p. 390) seems surprised at this case. On the relative colour’s of diurnal and nocturnal Lepidoptera, see ibid. p. 333 and 392 ; also Harris, ‘Treatise on the Insects of New England,’ J842, p. 315.
11 Such differences between the upper and lower surfaces of the wings of several species of Papilio, may be seen in the beautiful plates to Mr. Wallace’s Memoir on the Papilionidse of the Malayan Region, in ‘ transact. Linn. Soc.’ vol. xxv. part i. 1865.
Chap. XI.
BUTTERFLIES AND MOTHS.
397
to entomologists the most useful character for detecting the affinities of the various species.
Now if we turn to the enormous group of moths, which do not habitually expose to full view the under surface of their wings, this side is very rarely, as I hear from Mr. Stainton, coloured more brightly than the upper side, or even with equal brightness. Some ex- ceptions to the rule, either real or apparent, must be noticed, as that of Hypopyra, speci lied by Mr. W orrnabl.12 Mr. E. Trimen informs me that in Guenee’s great work, three moths are figured, in which the under surface is much the most brilliant. For instance, in the Australian Gastrophora the upper surface of the fore-wing is pale greyish-ochreous, while the lower surface is magnificently ornamented by an ocellus of cobalt-blue, placed in the midst of a black mark, surrounded by orange-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 colouring. Mr. Trimen also informs me that the lower surface of the wino-s in certain other Geometrae 13 and quadrifid Nocture are either more variegated or more brightly-coloured than the upper surface ; but some of these species have the habit of “ holding their wings quite erect over their “backs, retaining them in this position for a considerable “time,” and thus exposing to view the under surface. Other species when settled on the ground or herbage have the habit of now and then suddenly and slightly lifting up their wings. Hence the lower suiface of the wings being more brightly-coloured than the upper sur-
» ‘Proc. Ent. Soc.’ Mai ch 2nd, 1808.
13 See also an account of the S. American genus Erateina (one of the Geometrae) in fc Transact. Ent. Soc. new series, vol. v. pi. xv. and xvi.
398
SEXUAL SELECTION.
Pari II.
face in certain moths is not so anomalous a circum- stance as it at first appears. The Saturniidse include some of the most beautiful of all moths, their wings being decorated, as in our British Emperor moth, with fine ocelli; and Mr. T. W. Wood14 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, nor as far as I can discover hardly any foreign species, which are brilliantly coloured, differ much in colour according to sex; though this is the case with many brilliant but- terflies. The male, however, of one American moth, the Saturnia Io, is described as having its fore-wings deep yellow, curiously marked with purplish-red spots ; whilst the wings of the female arc purple-brown, marked with grey lines,15 The British moths which differ sexually in colour are all brown, or various tints of dull yellow, or nearly white. In several species the males are much darker than the females,16 and these belong to groups which generally fly about during the afternoon. On the other hand, in many genera, as Mr. Stainton informs me,
11 ‘Proc. Ent. Soc. of London,’ July 6, 1868, p. xxvii.
16 Harris, 1 Treatise,’ &e., edited by Flint, 1802, p. 395.
“ Tor instance, I observe in my son’s cabinet that the males are darker than the females in the Lasiocampa querc-us, (Jdonestis potatorum Bypogymna ditpar, Dusyehim pttdibuuda, and Cycnia mendica. In this latter species the difference in colour between the two sexes is strong)' marked ; and Mr. Wallace informs mo that we here have, as he believes. an instance of protective mimiekry confined to one sex, as will hereafter be more fully explained. The white female of the Cycnia resembles the very common Spihsoma meniUrasti, both sexes of which are white : and Mr. Stainton observed lhat 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, aud its white deceptive colour would thus be highly beneficial.
Chap. XI.
BUTTERFLIES AND MOTHS.
399
the males have the hind-wings whiter than those of the female — of which fact Agrotis exclamationis offers a good instance. The males are thus rendered more conspicuous than the females, whilst hying about in the dusk. In the Ghost Moth ( Eepialus humuli ) the difference is more strongly marked; the males being white and the females yellow with darker markings. It is difficult to conjecture what tlie meaning can be of these differences between the sexes in the shades of darkness or lightness; but wo can hardly suppose that they are the result of mere variability with sexually- limited inheritance, independently of any benefit thus derived.
From the foregoing statements it is impossible to admit that the brilliant colours of butterflies and of some few moths, have commonly been acquired for the sake of protection. We have seen that their colours and elegant patterns are arranged and exhibited as if for display. Hence I am led to suppose that the females generally prefer, or are most excited by the more brilliant males ; for on any other supposition the males would be ornamented, as for as we can see, for no purpose. We know that ants and certain lamellicorn beetles are capable of feeling an attachment for each other, and that ants recognise their fellows after an interval of several months. Hence there is no abstract improbability in the Lepidoptera, which pro- bably stand nearly or quite as high in the scale as these insects, having sufficient mental capacity to admire bright colours. They certainly discover flowers by colour, and, as I have elsewhere shewn, the plants which are fertilised exclusively by the wind never have a conspicuously-coloured corolla, l'he Humming-bird Sphinx may often be seen to swoop down from a distance on a bunch of flowers in the midst of green foliage ;
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SEXUAL SELECTION.
Part II.
and I have been assured by a friend, that these moths repeatedly visited flowers painted on the walls of a room in tire South of France, The common white butterfly, as 1 hear from Mr. Doubleday, often flies down to a bit of paper on the ground, no doubt mistaking it for one of its own species. Mr. Collingwood17 in speaking of the difficulty of 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 a prolonged affair. The males sometimes fight together in rivalry ; and many may bo seen pursuing or crowding round the same female. If, then, the females do not prefer one male to another, the pairing must be left to mere chance, and this does not appear to me a probable event. If, on the other hand, the females habitually, or even occasionally, prefer the more beautiful males, the colours of the latter will have been rendered brighter by degrees, and will have been transmitted to both sexes or to one sex, according to which law of inheritance prevailed. The process of sexual selection will have been much facili' tated, if the conclusions arrived at from various kinds of evidence in the supplement to the ninth chapter can be trusted ; namely that the males of many Lepidoptera, at least in the imago state, greatly exceed in number the females.
Some facts, however, are opposed to the belief that female butterflies prefer the more beautiful males ; thus, as I have been assured by several observers, fresh females may frequently be seen paired with battered, faded or
" ‘ Rambles of a Naturalist in the Chinese Seas,’ 1S68, p. 182,
Chap. XI.
BUTTERFLIES AND MOTHS.
401
dingy males ; but this is a circumstance which could hardly fail often to follow from the males emerging from their cocoons earlier than the females. With moths of the family of the Bombycidae, the sexes pair imme- diately 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. mori), as I have been told by some continental and English breeders. Dr. Wallace, who has had such immense experience in breeding Bombyx cynthia, is convinced that the females evince no choice or preference. He has kept above bOO of these moths living together, and has often found the most vigorous females mated with stunted males. The reverse apparently seldom occurs ; for, as he believes, the more vigorous males pass over the weakly females, being attracted by those endowed with most vitality. Although we have been indirectly in- duced to believe that the females of many species prefer the more beautiful males, I have no reason to suspect, either with moths or butterflies, that the males are attracted by the beauty of the females. If the more beautiful females had been continually preferred, it is almost certain, from the colours of butterflies being so frequently transmitted to one sex alone, that the females would often have been rendered more beautiful than their male partners. But this does not occur except in a few instances ; and these can be explained, as we shall presently see, on the principle of mimickry and protection.
As sexual selection primarily depends on variability, a few words must be added on this subject. In respect
VOL. i. 2d
402
SEXUAL SELECTION.
Pact II.
to colour there is no difficulty, as any number of highly variable Lepidoptera could be named. One good in- stance will suffice. Mi-. Bates shewed me a whole series of specimens of Papilio sesostris and childrens; in the latter the males varied much iu the extent of the beau- tifully enamelled green patch on the fore-wings, and in the size of the white mark, as well as of the splendid crimson stripe on the hind-wings; so that there was a great contrast between the most and least gaudy males. The male of Papilio sesostris, though a beautiful insect, is much less so than P. children re. It likewise varies a little in the size of the green patch on the fore- wings, and in the occasional appearance of a 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 -Tineas group possess this crimson stripe. Hence between the brightest specimens of P. sesostris and the least bright of P. children se, there was hut a small interval ; and it was evident that as far as mere variability is concerned, there would be no difficulty in permanently increasing by means of selec- tion the beauty of either species. The variability hero almost confined to the male sex; but Mr. "Wallace and Mr. Bates have shewn that the females of some other species are extremely variable, the males being nearly constant. As I have before mentioned the Ghost Moth ( Hepialus humuli ) as one of the best instances i11 Britain of a difference in colour between the sexes of moths, it may he worth adding19 that in the Shetland
18 Wallace on the Papiliouid® of tlie Malayan Region, in ‘ Transact. Linn. Soc.’ vol. xxv. 1805, p. 8, 3G. A striking case of a rare variety, strictly intermediate between two other well-marked female varieties, is given by Mr. Wallace. See also Mr. Bates, in ‘Ibne. Entomolog' Soc.’ Nov. 19th, 1SG6, p. xl.
19 Mr. E. MacLacldan, ‘ Transact. Ent. Soc.’ vol. ii. part Gtk, or series, 18GG, p, 459.
Chap. XI.
BUTTERFLIES AND MOTHS.
403
Islands, males are frequently found which closely resemble the females. In a future chapter I shall have occasion to shew that the beautiful eye-like spots or ocelli, so common on the wings of many Lepidoptera, are eminently variable.
On the whole, although many serious objections may be urged, it seems probable that most of the species of Lepidoptera which are brilliantly coloured, owe their colours to sexual selection, excepting in certain cases, presently to be mentioned, in which conspicuous colours are beneficial as a protection. From the ardour of the male throughout the animal kingdom, he is generally willing to accept any female ; and it is the female which usually exerts a choice. Hence if sexual selection has here acted, the male, when the sexes differ, ought to be the most brilliantly coloured ; and this undoubtedly is the ordinary rule. When the sexes are brilliantly co- loured and resemble each other, the characters acquired by the males appear to have been transmitted to both sexes. But will this explanation of the similarity and dissimilarity in colour between the sexes suffice?
The males and females of the same species of butterfly are known20 in several cases to inhabit different stations, the former commonly basking in the sunshine, the latter haunting gloomy forests. It is therefore possible that different conditions of life may have acted directly on the two sexes ; but this is not probable,21 as in the adult state they are exposed during a very short period to different conditions ; and the larval of both are ex- posed to the same conditions. Mr. Wallace believes
so H. W. Bates, ‘The Naturalist on tlie Amazons,’ vol. ii. 18G3, p. 228. A. R. Wallace, in ‘ Transact. Linn. .Soc.’ vol. xxv. 18G5, p. 10.
21 On this whole subject see ‘The Variation of Animals and Plants under Domestication,’ vol. ii. 1868, chap, xxiii.
2 d 2
404
SEXUAL SELECTIOX.
Fart II-
that the less brilliant colours of the female have been specially gained in all or almost all cases for the sake of protection. On the contrary it seems to me more probable that the males alone, in the large majority of cases, have acquired their bright colours through sexual selection, the females having been but little modified. Consequently the females of distinct but allied species ought to resemble each other much more closely than do the males of the same species ; and this is the general rule. The females thus approximately show us the pri- mordial colouring of the parent-species of the group to which they belong. They have, however, almost always been modified to a certain extent by some of the succes- sive steps of variation, through the accumulation of which the males were rendered beautiful, having been transferred to them. The nudes and females of allied though distinct species will also generally have been exposed during their prolonged larval state to different conditions, and may have been thus indirectly affected ; though with the males any slight change of colour thus caused will often have been completely masked by the brilliant tints gaiued through sexual selection. When we treat of Birds, I shall have to discuss the whole question whether the differences in colour between the males and females have been in part specially gained by the latter as a protection ; so that I will here only give unavoidable details.
In all eases when the more common form of equal inheritance by both sexes has prevailed, the selection of bright-coloured males would tend to make the females bright-coloured ; and the selection of dull-coloured fe- males would tend to make the males dull. If both pro- cesses were carried on simultaneously, they would tend to neutralise each other. As far as I can see, it would he extremely difficult to change through selection the
Chap. XI.
BUTTERFLIES AXD MOTHS.
405
one form of inheritance into the other. But hv the selection of successive variations, which were from the first sexually limited in their transmission, there would not be the slightest difficulty in giving bright colours to the males alone, and at the same time or subsequently, dull colours to the females alone. In this latter manner female butterflies and moths may, as I fully admit, have been rendered inconspicuous for the sake of protection, and widely different from their males.
Mr. Wallace 33 has argued with much force in favour of his view that when the sexes differ, the female has been specially modified for the sake of protection ; and that this has been effected by one form of inheritance, namely, the transmission of characters to both sexes, having been changed through the agency of natural selection into the other form, namely, transmission to one sex. I was at first, strongly inclined to accept this view ; but the more I have studied the various classes throughout the animal kingdom, the less probable it has appeared. Mr. Wallace urges that both sexes of the Keliconidm, Danaidm, Acra idm are equally brilliant because both are protected from the attacks of birds and other enemies, by their offensive odour ; but that iu other groups, which do not possess this immunity, the females have been rendered inconspicuous, from having more need of protection than the males, ffhis supposed difference in the “ need of protection by the “ two sexes ” is rather deceptive, and requires some discussion. It is obvious that brightly-coloured indi- viduals, whether males or females, would equally attract, and obscurely-coloured individuals equally escape, the
22 A. E. Wallace, in ‘ The Journal of Travel,’ vol. i, 1868, p. 88. 1 Westminster Review,’ July, 1867, p. 37. See also Messrs. Wallace and Bates iu ‘ Proc. Ent. Soc.’ Nov. 19th, 1866, p. xxxix.
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SEXUAL SELECTION.
Part II.
attention of their enemies. But we are concerned with the effects of the destruction or preservation of certain individuals of either sex, on the character of the race. With insects, after the male has fertilised the female, and after the latter has laid her eggs, the greater or less immunity from danger of either sex could not possibly have any effect on the offspring. Before the sexes have performed their proper functions, if they existed in equal numbers and if they strictly paired (all other circumstances being the same), the preservation of the males and females would be equally important for the existence of the species and for the character of the offspring. But with most animals, as is known to he the case with the domestic silk-moth, the male can fertilise two or three females ; so that the destruction of the males would not he so injurious to the species as that of the females. On the other hand, Dr. Wallace believes that with moths the progeny from a second or third fertilisation is apt to be weakly, and therefore would not have so good chance of surviving. When the males exist in much greater numbers than the females, no doubt many males might be destroyed with impunity to the species ; but I cannot see that the results of ordinary selection for the sake of protection would he inlluenced by the sexes existing in unequal numbers ; for the same proportion of the more con- spicuous individuals, whether males or females, would probably be destroyed. If indeed the males presented a greater range of variation in colour, the result would he different ; but we need not here follow out such com- plex details. On the whole I cannot perceive that an inequality in the numbers of the two sexes would in- fluence in any marked manner the effects of ordinary selection on the character of the offspring.
Bemale Lepidoptera require, as Mr. Wallace insists
Chap. XI.
BUTTERFLIES AND MOTHS.
407
some days to deposit their fertilised ova and to search for a proper place; during this period (whilst the life of the male was of no importance) the brighter-coloured females would be exposed to danger and would be liable to be destroyed. The duller-coloured females on the other hand would survive, aud thus would in- fluence, it might be thought, in a marked manner the character of the species, — either of both sexes or of one sex, according to which form of inheritance pre- vailed. But it must not be forgotten that the males emerge from the cocoon-state some days before the females, and during this period, whilst the unborn females were safe, the brighter-coloured males would be exposed to danger ; so that ultimately both sexes would probably be exposed during a nearly equal length oi time to danger, and the elimination of conspicuous colours would not be much more effective in the one than the other sex.
It is a more important consideration that female Lepidoptera, as Mr. Wallace remarks, and as is known to every collector, are generally slower flyers than the males. Consequently the latter, if exposed to greater danger from being conspicuously coloured, might be able to escape from their enemies, whilst the similarlv-coloured loin ales would he destroyed , and thus the females would have the most influence in modi- fying the colour of their progeny.
There is one other consideration: bright colours, as far as sexual selection is concerned, are commonly of no service to the iemales ; so that if the latter varied in brightness, and the variations were sexually limited in their transmission, it would depend on meio chance whether the females had their bright colours increased ; and this would tend throughout the Order to diminish the number of species with brightly-coloured females
408
SEXUAL SELECTION.
Part II.
in comparison with the species having brightly-coloured males. On the other hand, as bright colours are sup- posed to be highly serviceable to the males in their love-struggles, the brighter males (as we shall see in the chapter on Birds) although exposed to rather greater danger, would on an average procreate a greater number of offspring than the duller males. In this case, il the variations were limited in their transmission to the male sex, the males alone would be rendered more brilliantly coloured; but if the variations were not thus limited, the preservation and augmentation of such variations would depend on whether more evil was caused to the species by the females being rendered conspicuous, than good to the males by certain indivi- duals being successful over their rivals.
As there can hardly be a doubt that both sexes of many butterflies and moths have been rendered dull- coloured for the sake ot protection, so it may have been with the females alone of some species in which successive variations towards dullness first appeared in the female sex and were from the first limited in their transmission to the same sex. If not thus limited, both sexes would become dull-coloured. We shall immediately see, w'hen we treat of mimickry, that the females alone of certain butterflies have been ren- dered extremely beautiful for the sake of protection, without any of the successive protective variations having been transferred to the male, to whom they could not possibly have been in the least degree injuri- ous, and therefore could not have been eliminated through natural selection. Whether in each particular species, in which the sexes differ in colour, it is the female which has been specially modified for the sake of protection ; or whether it is the male which has been specially modified for the sake of sexual attraction, the
Chap. XI.
BUTTERFLIES AND MOTHS.
409
female having retained her primordial colouring only slightly changed through the agencies before alluded to; or whether again both sexes have been modified, the female for protection and the male for sexual attrac- tion, can only bo definitely decided when we know the life-history of each species.
Without distinct evidence, I am unwilling to admit that a double process of selection has long been going on with a multitude of species, — the males having been rendered more brilliant by beating their rivals ; and the females more dull-coloured by having escaped from their enemies. We may take as an instance the common brim- stone butterfly (G-onepteryx), which appears early in the spring before any other kind. The male of this species is of a far more intense yellow than the female, though she is almost equally conspicuous ; and in this case it does not seem probable that she specially acquired her pale tints as a protection, though it is probable that the male acquired his bright colours as a sexual attraction. The female of Anthocharis cardamines does not possess the beautiful orange tips to her wings with which the male is ornamented ; consequently she closely resembles the white butterflies (Pieris) so common in our wardens ; but we have no evidence that this resem- blance is beneficial. On the contrary, as she resembles both sexes of several species of the same genus inhabit- ing various quarters of the world, it is more probable that she has simply retained to a large extent her
primordial colours. _
Various facts support the conclusion that with the greater number of brilliantly-coloured Lepidoptera, it is the male which has been modified ; the two sexes having come to differ from each other, or to resemble each other, according to which form of inheritance has prevailed. Inheritance is governed by so many un-
410
SEXUAL SELECTION.
Part It
known laws or conditions, that they seem to ns to he most capricious in their action ; 23 and we can so far understand how it is that with closely-allied species the sexes of some differ to an astonishing degree, whilst the sexes ot others are identical in colour. As the successive steps in the process of variation are neces- sarily all transmitted through the female, a greater or less number of such steps might readily become developed in her; and thus we can understand the frequent gradations from an extreme difference to no difference at all between the sexes of the species within the same group. These cases of gradation are much too common to favour the supposition that we here see females actually undergoing the process of transition and losing their brightness for the sake of protection ; for we have every reason to conclude that at any one time the greater number of species are in a fixed condition. With respect to the differences between the females of the species in the same genus or family, we can perceive that they depend, at least in part, on the females partaking ot the colours of their respective males. rlhis is well illustrated in those groups in which the males are ornamented to an extraordinary degree j lor the females in these groups generally partake to a certain extent ot the splendour of their male partners. Lastly, we continually find, as already remarked, that the females of almost all the species in the same genus, or even family, resemble each other much more closely in colour than do the males ; and this indicates that the males have undergone a greater amount of modifi' cation than the females.
23 The Variation of Animals and Plants under Domestication, vol. ii. chap. xii. p. 17.
Chap. XI.
BUTTERFLIES AND MOTHS.
411
Mimichry.— This principle was first made clear in an admirable paper by Mr. Bates,24 who thus threw a flood of light on many obscure problems. It had previously been° observed that certain butterflies in S. America belonging to quite distinct families, resembled the Heli- coni dm so closely in every stripe and shade ot colour that they could not be distinguished except by an experienced entomologist. As the Heliconklm are coloured in their usual manner, whilst the others depart from the usual colouring of the groups to which they belong, it is clear that the latter are the imitators, and the Heliconidse the imitated. Mr. Bates further observed- that the imitating species are comparatively rare, whilst the imitated swarm in large numbers ; the two sets living mingled together. From the fact of the Heli- couidie being conspicuous aud beautiful insects, vet so numerous in individuals and species, he concluded that they must be protected from the attacks ot birds by some secretion or odour; and this hypothesis has now been confirmed by a considerable body of curious evidence.25 From these considerations Mr. Bates in- ferred that the butterflies which imitate the protected species had acquired their present marvellously decep- tive appearance, through variation and natural selection, in order to be mistaken for the protected kinds and thus to escape being devoured. No explanation is here attempted of the brilliant colours ol the imi- tated, but only of tho imitating butterflies. We must account for the colours of the former m the same general manner, as in the cases previously discussed m this chapter. Since the publication of Mr. Bates’ paper, similar and equally striking facts have been observed
=1 1 Transact. Linn. Soc.’ vol. xxiii. 18G2, p. 495. 25 < Proc. Ent. Soc.’ Dec. 3rd, 1866, p. xlv.
412
SEXUAL SELECTION.
Part II.
by Mi. Wallace26 in the Malayan region, and by Mr. Trimen in South Africa.
As some writers 27 have felt much difficulty in under- standing how the first steps in the process of mimickrv could have been effected through natural selection, it may be well to remark that the process probably has never commenced with forms widely dissimilar in colour. l>ut with two species moderately like each other, the closest resemblance if beneficial to either form could readily be thus gained ; and if the imitated form was subsequently and gradually modified through sexual selection or any other means, the imitating form would be led along the same track, and thus be modified to almost any extent, so that it might ultimately assume an appearance or colouring wholly unlike that of the other members of the group to which it belonged. As extremely slight variations in colour would notin many cases suffice to render a species so like another pro- tected species as to lead to its preservation, it should be remembered that many species of Lepidoptera are liable to considerable and abrupt variations in colour. A few instances have been given in this chapter; but under this point of view Mr. Bates’ original paper on mimickry, as well as Mr. Wallace’s papers, should be consulted.
In the foregoing cases both sexes of the imitating species resemble the imitated; but occasionally the
26 ‘Transact. Linn. Soo.’ vol. xxv. 1SG5, p. 1; also ‘ Transact. Ent. Soc. vol. iv. (3rd series), 1807, p. 301.
See an ingenious article entitled, “Difficulties oftlie Theory of Natural Selection,” in the * Month/ 18G9. The writer strangely sup- poses that 1 attribute the variations in colour of the Lepidoptera, by which certain species belonging to distinct families have come to resemble others, to reversion to a common progenitor ; but there is no more reason to attribute these variations to reversion than in the oase of any ordinary variation.
Chap. XI.
BUTTERFLIES AND MOTHS.
413
female alone mocks a brilliantly-coloured and protected species inhabiting the same district. Consequently the female differs in colour from her own male, and, which is a rare and anomalous circumstance, is the more brightly-coloured of the two. In all the few species of Pieridae, in which the female is more conspicuously coloured than the male, she imitates, as I am informed by Mr. Wallace, some protected species inhabiting the same region. The female of Diadema anomala is rich purple-brown with almost the whole surface glossed with satiny blue, and she closely imitates the Euplcea rnida- mus, “one of the commonest butterflies of the East;” whilst the male is bronzy or olive-brown, with only a slight blue gloss on the outer parts of the wings.28 Both sexes of this Diadema and of I). Mina follow the same habits of life, so that the differences in colour between the sexes cannot be accounted for by exposure to different conditions;29 even if this explanation were admissible in other instances."0
The above cases of female butterflies which are more brightly-coloured than the males, shew us, firstly, that variations have arisen in a state of nature in the female sex, and have been transmitted exclusively, or almost ex- clusively, to the same sex ; and, secondly, that this form of inheritance has not been determined through natural selection. For if we assume that the females, before they became brightly coloured in imitation of some pro- tected kind, were exposed during each season for a longer period to danger than the males ; or if we assume that
28 Wallace, 14 Notes on Eastern Butterflies, Transact. Ent. feoc. 1869, p. 287.
23 Wallace, in ‘Westminster Beview,’ July, 1867, p. 37; and in ‘ Journal of Travel and Nat. Hist. vol. i. 1868, p. SS.
30 See remarks by Messrs. Bates and Wallace, in ‘ Proc. Ent. Soc.’ Nov. 19, 1866, p. xxxix.
414
SEXUAL SELECTIOX.
Part II.
they could not escape so swiftly from their enemies, we can understand how they alone might originally have acquired through natural selection and sexually- limited inheritance their present protective colours. But except on the principle of these variations having been transmitted exclusively to the female offspring, we cannot understand why the males should have re- mained dull-coloured ; for it would surely not have been in any way injurious to each individual male to have partaken by inheritance of the protective colours of the female, and thus to have had a better chance of escaping destruction. In a group in which brilliant colours are so common as with butterflies, it cannot be supposed that the males have been kept dull-coloured through sexual selection by the females rejecting the individuals which were rendered as beautiful as them- selves. We may, therefore, conclude that in these cases inheritance by one sex is not due to the modification through natural selection of a tendency to equal inherit- ance by both, sexes.
It may be well here to give an analogous case in another Order, of characters acquired only by the female, though not in the least injurious, as far as we can judge, to the male. Amongst the Phasmidse, or spectre-insects, Mr. Wallace states that “it is often the females alone “ that so strikingly resemble leaves, while the males show “only a rude approximation.” Now, whatever may be the habits of these insects, it is highly improbable that it could be disadvantageous to the males to escape de- tection by resembling leaves.'51 Hence we may conclude
31 See Mr. Wallace in ‘Westminster lie view,' July, 1867, p. 11 an>l 37. The male of no butterfly, as Mr. Wallace informs me, is known to differ in colour, as a protection, from the female ; and he asks me how I can explain this fact on the principle that one sex alone has varied and has transmitted its variations exclusively to the same sex, without
Chap. XI.
BUTTEKFLIES AND MOTHS.
415
that the females alone in this latter as in the previous cases originally varied in certain characters ; these cha- racters having been preserved and augmented through ordinary selection lor the sake of protection and from the first transmitted to the female offspring alone.
Bright Colours of Caterpillars. — Whilst reflecting on the beauty of many butterflies, it occurred to me that some caterpillars were splendidly coloured, and as sexual selection could not possibly have here acted, it appeared rash to attribute the beauty of the mature insect to this agency, unless the bright colours of their larvae could be in some manner explained. In the first place it may be observed that the colours of caterpillars do not stand in any close correlation with those of the mature insect. Secondly, their bright colours do not
the aid of select ion io clieok the variations being inherited by the other sex. No doubt if it could be shewn that the females ol' very many species had been rendered beautiful through protective niimickry, hut that this has never occurred with tlie males, it would be a serious difficulty. But the number of eases os yet known hardly suffices for a fair judgment. We can see that the males, from having the power of flying more swiftly, and thus escaping danger, would not be so likely as the females to have had fheir colours modified for the sake of protec- tion; but this would not in the least have interfered with their receiving protective colours through inheritance from the females. In the second place, it is probable tbat sexual selection would actually tend to picveut abeautiful male from becoming obscure, for the less brilliant. individuals would he less attractive to the females. Supposing that the beauty of the male of any species had been mainly acquired through sexual selection, yet if this beauty likewise served as a protection, the acquisi- tion would have been aided by' natural selection. But it would be quite beyond our power to distinguish between the two processes ot sexual and ordinary selection. Hence it is not likely that we should he able to adduce eases of the males having been rendered brilliant exclusively through protective niimickry, though this is comparatively easy with the females, which have rarely or never been rendered beau- tiful, as far as we can judge, fur the sake ol sexual attraction, although they have often received beauty through inheritance from their male parents.
416
SEXUAL SELECTIOX.
Part II.
serve in any ordinary manner as a protection. As an instance of this, Mr. Bates informs me tiiat the most conspicuous caterpillar which he ever beheld (that of a Sphinx) lived on the large green leaves of a tree on the open llanos of South America ; it was about four inches in length, transversely banded with black and yellow, and with its head, legs, and tail of a bright red. Hence it caught the eye of any man who passed by at the distance of many yards, and no doubt of every passing bird.
I then applied to Mr. Wallace, who has an innate genius for solving difficulties. After some consideration he replied: “Most caterpillars require protection, as “ may be inferred from some kinds being furnished “ with spines or irritating hairs, and from many being “ coloured green like the leaves on which they feed, “ or curiously like the twigs of the trees on which they “ live.” 1 may add as another instance of protection, that there is a caterpillar of a moth, as I am informed by Mr. J. Mansel Weale, which lives on the mimosas in South Africa, and fabricates for itself a case, quite un- distinguishable from the surrounding thorns. From such considerations Mr. Wallace thought it probable that conspicuously-coloured caterpillars were protected by having a nauseous taste ; but as their skin is ex- tremely tender, and as their intestines readily protrude from a wound, a slight peck from the beak of a bird would be as fatal to them as if they had been devoured. Hence, as Mr. W allace remarks, “distastefulness alone “ would be insufficient to protect a caterpillar unless “ some outward sign indicated to its would-be destroyer “ that its prey was a disgusting morsel.” Under these circumstances it would bo highly advantageous to a caterpillar to be instantaneously and certainly recog- nised as unpalatable by all birds and other animals-
Chap. XI.
SUMMARY ON INSECTS.
417
Thus the most gaudy colours would be serviceable, and might have been gained by variation and the survival of the most easily-recognised individuals.
This hypothesis appears at first sight very bold ; but when it was brought before the Entomological Society32 it was supported by various statements ; and Mr. J. Jenner Weir, who keeps a large number of birds in an aviary, has made, as he informs me, numerous trials, and finds no exception to the rule, that all caterpillars of nocturnal anil retiring habits with smooth skins, all of a green colour, and all which imitate twigs, are greedily devoured by his birds. The hairy and spinose kinds are invariably rejected, as were four conspicuously- coloured species. When the birds rejected a caterpillar, they plainly shewed, by shaking their heads and cleans- ing their beaks, that they wore disgusted by the taste.33 Three conspicuous kinds of caterpillars and moths were also given by Mr. A. Butler to some lizards and frogs, and were rejected ; though other kinds were eagerly eaten. Thus the probable truth of Mr. Wallace’s view is confirmed, namely, that certain caterpillars have been made conspicuous lor their own good, so as to lie easily recognised by their enemies, on nearly the same prin- ciple that certain poisons are coloured by druggists for the good of man. This view will, it is probable, be hereafter extended to many animals, which are coloured in a conspicuous manner.
Summary and Concluding Hemarlts on Insects. — Looking back to the several Orders, we have seen that the sexes often differ in various characters, the meaning
32 * Proc. Entomolog. Soc.’ Dec. 3rd, 1866, p. xlv., and March 4th, 1S67, p. Ixxx.
33 See Mr. J. Jenner AVeir’s paper on insects and insectivorous birds, in 1 Transact. Ent. Soc.' 1869, p. 21 ; also Mr. Butler’s paper, ibid p. 27.
VOL. I. ^ E
418
SEXUAL SELECTION.
Part II.
of which is not understood. The sexes, also, often differ in their organs of sense or locomotion, so that the males may quickly discover or reach the females, and still oftener in the males possessing diversified contrivances for retaining the females when found. But we are not here much concerned with sexual differences of these kinds.
In almost all the Orders, the males of some species, even of weak and delicate kinds, are known to be hisrhly pugnacious ; and some few are furnished with special weapons for fighting with their rivals. But the law of battle does not prevail nearly so widely with insects as with the higher animals. Hence probably it is that the males have not often been rendered larger and stronger than the females. On the contrary they are usually smaller, in order that they may be developed within a shorter time, so as to be ready in large numbers for the emergence of the females.
In two families of the Homoptera the males alone possess, in an efficient state, organs which may be called vocal ; and in three families of the Orthoptera the males alone possess stridulating organs. In botli cases these organs are incessantly used during the breeding-season, not only for calling the females, but for charming or exciting them in rivalry with other males. No one who admits the agency of natural selection, will dispute that these musical instruments have been acquired through sexual selection. In four other Orders the members of one sex, or more commonly of both sexes, are provided until organs for producing various sounds, which apparently serve merely as call-notes. Even when both sexes are thus provided, the individuals which were able to make the loudest or most continuous noise would gain partners before those which were less noisy, so that their organs have probably been gained
Chap. XI.
SUMMARY ON INSECTS.
419
through, sexual selection. It is instrutive to reflect on the wonderful diversity of the means for producing sound, possessed by the males alone or by Loth sexes in no less than six Orders, and which were possessed by at least one insect at an extremely remote geolo- gical epoch. We thus learn how effectual sexual selec- tion has been in leading to modifications of structure, which sometimes, as with the Homoptera, are of an im- portant nature.
From the reasons assigned in the last chapter, it is probable that the great horns of the males of many lamellicorn, and some other beetles, have been ac- quired as ornaments. So perhaps it may bo with cer- tain other peculiarities confined to the male sex. From the small size of insects, we are apt to undervalue their appearance. If we could imagine a male Chalcosoma (fig. 15) with its polished, bronzed coat of mail, and vast complex horns, magnified to the size of a horse or even of a dog, it would be one of the most imposing- animals in the world.
The colouring of insects is a complex and obscure subject. When the male differs slightly from the female, and neither are brilliantly coloured, it is probable that the two sexes have varied in a slightly different manner, with the variations transmitted to the same sex, without any benefit having been thus derived or evil suffered. When the male is brilliantly coloured and differs con- spicuously from the female, as with some dragon-flies and many butterflies, it is probable that he alone has been modified, and that be owes bis colours to sexual selection ; whilst the female has retained a primordial or very ancient type of colouring, slightly modified by the agencies before explained, and has therefore not been rendered obscure, at least in most cases, for the sake of protection. But the female alone has some-
2 E 2
420
SEXUAL SELECTION.
Pakt II.
times been coloured brilliantly so as to imitate other protected species inhabiting the same district. When the sexes resemble each other and both are obscurely coloured, there is no doubt that they have been in a multitude of cases coloured for the sake of protection. So it is in some instances when both are brightly coloured, causing them to resemble surrounding objects such as flowers, or other protected species, or indirectly by giving notice to their enemies that they are of an unpalatable nature. In many other cases in which the sexes resemble each other and are brilliantly coloured, especially when the colours are arranged for display, we may conclude that they have been gained by the male sex as an attraction, and have been transferred to both sexes. We arc more especially led to this conclusion whenever the same type of coloration prevails through- out a group, and we find that the males of some species differ widely in colour from the females, whilst both sexes of other species are quite alike, with intermediate gradations connecting these extreme states.
In the same manner as bright colours have often been partially transferred Jfom the males to the females, so it has been with the extraordinary horns of many lamellicorn and some other beetles. So, asain, the vocal or instrumental organs proper to the males of the Homoptera and Orthoptera have generally been transferred in a rudimentary, or even in a nearly perfect condition to the females; yet not sufficiently perfect to be used for producing sound. It is also an interesting fact, as bearing on sexual selection, that the stridulating organs of certain male Orthoptera are not fully deve- loped until the last moult ; and that the colours of cer- tain male dragon-flies are not fully developed until some little time after their emergence from the pupal state, and when they are ready to breed.
Chap. XI.
SUMMARY ON INSECTS.
421
Sexual selection implies that the more attractive individuals are preferred by the opposite sex ; and as with insects, when the sexes differ, it is the male which, with rare exceptions, is the most ornamented and departs most from the type to which the species belongs; — and as it is the male which searches eagerly for the female, we must suppose that the females habit- ually or occasionally prefer the more beautiful males, and that these have thus acquired their beauty. That the females in most or all the orders would have the power of rejecting any particular male, is probable from the many singular contrivances possessed by the males, such as great jaws, adhesive cushions, spines, elongated legs, &c., for seizing the female ; for these contrivances shew that there is some difficulty in the act. In the case of unions between distinct species, of which many instances have been recorded, the female must have been a consenting party. Judging from what we know of the perceptive powers and affections of various insects, there is no antecedent im- probability in sexual selection having come largely into action ; but we have as yet no direct evidence on this head, and some facts are opposed to the belief. Never- theless, when we see many males pursuing the same female, we can hardly believe that the pairing is left to blind chance— that the female exerts no choice, and is not influenced by the gorgeous colours or other ornaments, with which the male alone is decorated.
If we admit that the females of the Homoptera and Orthoptera appreciate the musical tones emitted by their male partners, and that the various instruments for this purpose have been perfected through sexual selection, there is little improbability in the iemales ot other insects appreciating beauty in form or colour, and con- sequently in such characters having been thus gained
422
SEXUAL SELECTION.
Part II.
by the males. But from the circumstance of colour being so variable, and from its having been so often modified for the sake of protection, it is extremely difficult to decide in how large a proportion of cases sexual selection has come into play. This is more especially difficult in those Orders, such as the Orthop- tera, Hymenoptera, and Coleoptera, in which the two sexes rarely ditfer much in colour ; for wre are thus cut off from our best evidence of some relation between the reproduction of the species and colour. With the Coleoptera, however, as before remarked, it is in the great lamellicorn group, placed by some authors at the head of the Order, and in which we sometimes see a mutual attachment between the sexes, that we find the males of some species possessing weapons for sexual strife, others furnished with wonderful horns, many with stridulatiug organs, and others ornamented with splendid metallic tints. Hence it seems probable that all these characters have been trained through
O O
the same means, namely sexual selection.
When we treat of Birds, we shall see that they pre- sent in their secondary sexual characters the closest analogy with insects. Thus, many male birds are highly pugnacious, and some are furnished with special weapons for fighting with their rivals. They possess organs which are used during the breeding-season for producing vocal and instrumental music. They are frequently ornamented with combs, horns, wattles and plumes of the most diversified kinds, and are decorated with beautiful colours, all evidently for the sake of dis- play. We shall find that, as with insects, both sexes, in certain groups, are equally beautiful, and are equally provided with ornaments which are usually confined to the male sex. In other groups both sexes are equally plain-coloured and unornamented. Lastly, in some few
CriAP. XI.
SUMMAKY ON INSECTS.
423
anomalous cases, the females are more beautiful than the males. We shall often find, in the same group of birds, every gradation from no difference between the sexes, to an extreme difference. In the latter case we shall see that the females, like female insects, often possess more or less plain traces of the characters which properly belong to the males. The analogy, indeed, in all these respects between birds and insects, is curiously close. "Whatever explanation applies to the one class probably applies to the other ; and this explanation, as wye shall hereafter attempt to shew, is almost certainly sexual selection.
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— — —
THE DESCENT OF MAN,
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THE
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SELECTION IN RELATION TO SEX.
By CHARLES DARWIN, M.A., P.R.S., &c.
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[ The right of Translation is reserved .]
BY THE SAME AUTHOR.
ON THE ORIGIN OF SPECIES BY MEANS OF NATURAL
SELECTION ; or, The Preservation of Favoured Races in the Struggle for Life. Filth Edition {Tenth Thousand), with Additions and Corrections. 1869, Murray.
THE VARIATION OF ANIMALS AND PLANTS UNDER
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CONTENTS
PART II.
SEXUAL SELECTION — continued.
CHAPTER XII.
Secondary Sexual Characteks of Fishes, Amphibians, and Reptiles.
Wishes : Courtship and battles of the males — Larger size of the females — Males, blight colours aud ornamental appendages ; other strange characters — Colours and appendages acquired by the males during the breeding-season alone — Fishes with both sexes brilliantly coloured — Protective colours — The less con- spicuous colours of the female canuot he accounted for on the principle of protection — Male fishes building nests, and taking charge of the ova and young. Amphibians : Differences in structure and colour between the sexes — Yocal organs. Rep- tiles : Chelonians — Crocodiles — Snakes, colours in some cases protective — Lizards, battles of — Ornamental appendages — Strange differences in structure between the sexes — Colours — Sexual differences almost as great as with birds .. Page 1-37
CHAPTER XIII.
Secondary Sexual Characters of Birds.
Sexual differences — Law of battle — Special weapons — Vocal organs — Instrumental music — Love-antics and dances — Deco- rations, permanent and seasonal — Double and single annual moults — Display of ornaments by the males 38-98
VI
CONTENTS OF VOL. II.
CHAPTER XIV.
Birds — continued.
Choice exerted by the female — Length of courtship — Unpaired birds- — Mental qualities and taste for the beautiful — Preference or antipathy shewn by the female for particular males — Vari- ability of birds — Variations sometimes abrupt — Laws of varia- tion— Formation of ocelli — Gradations of character — Case of Peacock, Argus pheasant, and Urosticte .. .. Page 99-153
CHAPTER XV.
Birds — continued.
Discussion why the males alone of some species, and both sexes of other species, are brightly coloured — On sexually-limited inheritance, as applied to various structures and to brightly- coloured plumage — Nidification in relation to colour — Loss of nuptial plumage during the winter 154-182
CHAPTER XVI.
Birds — concluded.
The immature plumage in relation to the character of the plumage in both sexes when adult — Six classes of cases — Sexual differ- ences between the males of closely-allied or representative species — The female assuming the characters of the male — Plumage of the young in relation to the summer and winter plumage of the adults — On the increase of beauty in the Birds of the World — Protccti ve colouring — Conspicuously-coloured birds — Novelty appreciated — Summary of the four chapters on birds 183-238
CONTENTS OF VOL. II.
Vll
CHAPTEE XYIT.
Secondaky Sexual Characters of Mammals.
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 ot such weapons — Their high importance — Greater size of the male Means of defence — On the preference shewn by either sex in the pairing of quadrupeds Page 239-273
CHAPTEE XVIII.
Secondary Sexual Characters of Mammals — continued.
Voice — Remarkable sexual peculiarities in seals — Odour — Deve- lopment of the hair — -Colour of the hair and skin — Anomalous case of the female being more ornamented than the male — Colour and ornaments due to sexual selection — Colour acquired for the sake of protection — Colour, though common to both sexes, often due to sexual selection — On the disappearance of spots and stripes in adult quadrupeds — On the colours and ornaments of the Quadrumana — Summary .. .. 274-315
CHAPTEE XIX.
Secondary Sexual Characters of Man.
Differences between man and woman — Causes of such differences and of certain characters common to both sexes — Law of battle - — Differences in mental powers — and voice — On the influence of beauty in determining the marriages of mankind — Attention paid by savages to ornaments — Their ideas of beauty in woman — The tendency to exaggerate each natural peculiarity 316-354
Vlll
CONTENTS OF VOL II.
CHAPTER XX.
Secondary Sexual Characters of Man — continued.
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 civilised and savage nations ' Conditions favourable to sexual selection during primeval times On the manner of action ot sexual selection with man- kind— On the women in savage tribes having some power to choose their husbands — Absence of hair on the body, and deve- lopment of the beard — Colour of the skin — Summary 355-384
CHAPTER XXI.
General Summary and Conclusion.
Main conclusion that man is descended from some lower form
Manner of development— Genealogy of man — Intellectual and moral faculties — Sexual selection — Concluding remarks 385-405
Index
.. 406
SEXUAL SELECTION.
CHAPTER XII.
Secondary Sexual Characters of Fishes, Amphibians, and Reptiles.
Pishes : Courtship and battles of the males — Larger size of the females — Males, bright colours and ornamental appendages; other strange characters — Colours and appendages acquired by the males during the breeding-season alone — Fishes with both sexes brilliantly coloured — Protective colours — The less con- spicuous colours of the female cannot he accounted for on the principle of protection — Male fishes building nests, and taking charge of the ova and young. Amphibians : Differences in structure and colour between the sexes — Vocal organs. Rep- tiles : Chelonians — Crocodiles — Snakes, colours in some cases Protective — Lizards, battles of — Ornamental appendages — Strange differences in structure between the sexes — Colours - Sexual differences almost as great as with birds.
^ E have now arrived at the great sub-kingdom of the ei’tebrata, and will commence witli the lowest class, barnely Fishes. The males of Plagiostomous fishes (.s larks, rays) and of Chinneroid fishes are provided "ith claspers which serve to retain the female, like the 'ations structures possessed by so many of the lower ■Vu nials. Besides the claspers, the males of many rays a^e clusters of strong sharp spines on their heads, au< several rows along “ the upper outer surface of their pectoral fins.” These are present in the males of some species, which have the other parts of their bodies
V°L. ix. j.
2
SEXUAL SELECTION.
Part II.
smooth. They are only temporarily developed during the breeding-season ; and Dr. Gunther suspects that they are brought into action as prehensile organs by the doubling inwards and downwards of the two sides of the body. It is a remarkable fact that the females and not the males of some species, as of liaia clavata, have their backs studded with large hook-formed spines.1
Owing to the element which fishes inhabit, little is known about their courtship, and not much about their battles. The male stickleback ( Gasferosteus Jei- urus) has been described as “mad with delight” when the female comes out of her hiding-place and surveys the nest which he has made for her. “ He darts round “ her in every direction, then to his accumulated ma- “ terials for the nest, then back again in an instant; “ and as she does not advance lie endeavours to push “ her with his snout, and then tries to pull her by the “ tail and side-spine to the nest.”2 The males are said to be polygamists ;3 they are extraordinarily bold and pugnacious, whilst “ the females are quite pacific.” Their battles are at times desperate; “for these puny “ combatants fasten tight on each other for several “ seconds, tumbling over and over again, until their “ strength appears completely exhausted.” With the rough-tailed stickleback (G. irachurus) the males whilst fighting swim round and round each other, biting and endeavouring to pierce each other with their raised lateral spines. The same writer adds,4 “ the bite of these little
1 Yarrell’s ‘ Hist, of British Fishes,’ vol. ii. 1836, p. 417, 425, 436. Dr. Gunther informs me that the spines in II. clavata are peculiar to the female.
2 See Mr. R. Waringtou’s interesting articles in 1 Annals and Mag. of Nat. Hist.’ Oct. 1852 and Nov. 1855.
8 Noel Humphreys, ‘River Gardens,’ 1857.
4 Loudon's ‘ Mag. of Natural History,’ vol. iii. 1830, p. 331.
'-’HAP. XII.
FISHES.
3
11 furies is very severe. They also use their lateral spiues “ with such fatal effect, that I have seen one during a “ battle absolutely rip his opponent quite open, so that “ he sank to the bottom aud died.” When a fish is conquered, “ his gallant bearing forsakes him ; his gay “ colours fade away; and he hides his disgrace among “ bis peaceable companions, but is for some time the “ constant object of his conqueror’s persecution.”
The male salmon is as pugnacious as the little stickle- back; and so is the male trout, as I hear from Dr. Gunther. Mr. Shaw saw a violent contest between two I,!ale salmons which lasted the whole day ; and Mr. R. buist, Superintendent of Fisheries, informs me that he bas often watched from the bridge at Perth the males driving away their rivals whilst the females were spawn- big. The males “ are constantly fighting and tearing “ each other on the spawning-beds, and many so injure “ each other as to cause the death of numbers, many “ being seen swimming near the banks of the river in “ a state of exhaustion, and apparently in a dying state.”5 The keeper of the Stormontfield breeding- pomls visited, as Mr. iiuist informs me, in June, 1868, the northern Tyne, and found about 300 dead salmon, all of which with one exception were males ; and he was convinced that they had lost their lives by fighting.
The most curious point about the male salmon is that during the breeding-season, besides a slight change 'c colour, “ the lower jaw elongates, and a cartilaginous “ projection turns upwards from the point, which, when the jaws are closed, occupies a deep cavity between
5 ‘The Field,’ June 29th, 1867. For Mr. Shaw’s statement, see Edinburgh Review,’ 18-13. Another experienced observer (Scrope’s Days of Salmon Fishing,’ p. 60) remarks that the male would, if he could, keep, like the stag, all other males away.
B 2
4
SEXUAL SELECTION.
Paet II.
“ the intermaxillary bones of tlie upper jaw.”6 (Figs. 26 and 27.) In our salmon this change of structure lasts only during the breeding-season ; but in the Salmo h/caodon of N.W. America the change, as Mr. J. K.
Fig. 26. Head of male of common salmon (Salmo solar) during the breeding-season.
[This drawing, as well as all the others in the present chapter, have been executed bv the well-known artist, Mr. (J. Ford, under the kind superintendence of Dr. Gunther from specimens in the British Museum.]
6 Yarrell, 1 History of British Fishes, ’ vol. ii. 1836. p. 10,
Chap. XII.
FISHES.
5
01 c believes, is permanent and best marked in the o c er males which have previously ascended the rivers, n t ese old males the jaws become developed into im- mense look-like projections, and the teeth grow into
Withal ^ °^eU more ttan half an inch in length. 6 luoPean- salmon, according to Mr. Lloyd,8
a 1 ScaTiaintU'-a'iSt m ^ ancouver’s Island,’ vc ,
lavian Adventures,’ vol. i. 1854, p. 100, 104.
vol. i. 1866, p.
6
SEXUAL SELECTION.
Part II.
the temporary hook-like structure serves to strengthen and protect the jaws, when one male charges another with wonderful violence ; but the greatly developed teeth ot‘ the male American salmon may be compared with the tusks of many male mammals, and they indicate an offensive rather than a protective purpose.
The salmon is not the only fish in which the teeth differ in the two sexes. This is the case with many rays. In the thorn back (Ram clavata ) the adult male has sharp, pointed teeth, directed backwards, whilst those of the female are broad and flat, forming a pave- ment ; so that these teeth differ in the two sexes of the same species more than is usual in distinct genera of the same family. The teeth of the male become sharp only when he is adult : whilst young they are broad and flat like those of the female. As so frequently occurs with secondary sexual characters, both sexes of some species of rays, for instance B. bath, possess, when adult, sharp, pointed teeth; and here a character, proper to and primarily gained by the male, appears to have been transmitted to the offspring of both sexes. The teeth are likewise pointed in both sexes of B. maculata, but only when completely adult ; the males acquiring them at an earlier age than the females. We shall hereafter meet with analogous cases with certain birds, in which the male acquires the plumage common to both adult sexes, at a somewhat earlier age than the female. With other species of rays the males even when old never possess sharp teeth, and consequently botli sexes when adult are provided with broad, flat teeth like those of the young, and of the mature females of the above-mentioned species.9 As the rays are bold.
9 See Yarrell’s account of the Bays in his ‘ Hist, of British Fishes,’ vol. ii. 1836, p. 416, with an excellent figure, and p. 422, 432.
Chap. XII.
FISHES.
7
strong and voracious fishes, we may suspect that the males require their sharp teeth for fighting with their rivals ; but as they possess many parts modified and adapted for the prehension of the female, it is possible that their teeth may be used for this purpose.
In regard to size, M. Carbonuier10 maintains that with almost all fishes the female is larger than the male ; and Dr. Gunther does not know of a single instance in which the male is actually larger than the female.
itli some Cyprinodonts the male is not even half as large as the female. As with many kinds of fishes the males habitually fight together ; it is surprising that they have not generally become through the etiects of sexual selection larger and stronger than the females. The males suffer from their small size, for according to I'd • Carbonuier they are liable to be devoured by the females of their own species when carnivorous, and no doubt by other species. Increased size must be in some manner of more importance to the females, than strength and size are to the males for fighting with other males ; and this perhaps is to allow of the pro- duction of a vast number of ova.
In many species the male alone is ornamented with bright colours ; or these are much brighter in the male than the female. The male, also, is sometimes provided with appendages which appear to be of no more use to him for the ordinary purposes of life than are the tail- feathers to the peacock. I am indebted for most of the following facts to the great kindness of Dr. Gunther. I here is reason to suspect that many tropical fishes differ sexually in colour and structure ; and there are some striking cases with our British fishes. The male Qallionymus lyra has been called the gemrneous dragonet
10 As quoted in ‘ The Farmer,’ X86S, p. 3G9.
8
SEXUAL SELECTION.
Pact II.
“ from its brilliant gem-like colours.” When freshly taken from the sea the body is yellow of various shades, striped and spotted with vivid blue on the head ; the dorsal fins are pale brown with dark longitudinal bands ; the ventral, caudal and anal fins being bluish-black. The female, or sordid dragonet, was considered by Lin- naeus and by many subsequent naturalists as a distinct
Fig. 28. Calllonymus lyra. Upper figure, male; lower figure, female.
N.B. I he lower figure is more reduced than the upper.
species ; it is ot a dingy reddish-brown, with the dorsal fin brown and the other fins white. The sexes differ also in the proportional size of the head aud mouth, and in the position of the eyes ; 11 but the most striking differ- rence is the extraordinary elongation in the male (fig. 28)
11 I have drawn up this description from Yarrell’s ‘ British Fishes ’ vol. i. 1836, p. 261 and 266.
Chap. XII.
FISHES.
9
°f the dorsal fin. The young males resemble in struc- ture and colour the adult females. Throughout the genus Callionymus,13 the male is generally much more brightly spotted than the female, and iu several species, not only the dorsal, but the anal fin of the male is much elongated.
rThe male of the Cottus scorpius , or sea-scorpion, is more lender and smaller than the female. There is also a gi'eat difference in colour between them. It is difficult, us Mr. Lloyd13 remarks, “for any oue, who has not seen ‘ this fish during the spawning-season, when its hues are ' brightest, to conceive the admixture of brilliant colours ! "’ith which it, in other respects so ill-favoured, is at ' that time adorned.” Loth sexes of the Labrus inixtus, although very different in colour, arc beautiful; the male being orange with bright-blue stripes, and the female bright-red with some black spots on the back.
In the very distinct family of the Cyprinodontidse — '■"habitants of the fresh waters of foreign lands — the Sexes sometimes differ much in various characters. In the male of the Mollienesia petenensis the dorsal fin is greatly developed and is marked with a row of large, round, ocellated, bright-coloured spots ; whilst the same tin in the female is smaller, of a different shape, and "narked only with irregularly-curved brown spots. In the male the basal margin of the anal fin is also a little Produced and dark-coloured. In the male of an allied torni, the Xiphophorus Hellerii (fig. 29), the inferior Margin of the anal fin is developed into a long filament,
Catalogue of Acanth. Fishes in the British Museum,’ by Dr. ,3nt:her, 1861, p. 188-151. u wr-ame °f Sweden,’ &c., 18G7, p. 460.
Br vf ttk respect to this and the following species I am indebted to (j1- Ciinther for information: see also his paper on the Fishes of en la,t America, in ‘ Transact. Zooiog. Soe.’ yol. vi. 1868, p. 485.
10
SEXUAL SELECTION.
Part II.
which is striped, as I hear from Dr. Gunther, with bright colours. This filament does not contain any muscles, and apparently cannot be of any direct use to the fish. As in the case of the Callionymus, the males whilst young resemble in colour and structure the adult females. Sexual differences such as these may be strictly compared with those which are so frequent with gallinaceous birds.15
Fig. 2'J. Xiphophoras Ilollerii. Upper figure, male ; lower figure, female.
In a siluroid fish, inhabiting the fresh waters of South America, namely the Plecostomus barbatus 16 (fig. SO), the male has its mouth and interoperculum fringed with a beard of stiff hairs, of which the female shews hardly a trace. These hairs are of the nature of scales. In another species of the same genus, soft flexible ten- tacles project from the front part of the head of the
is Dr. Giintlier makes this remark; ‘Catalogue of Fishes in the British Museum,’ vol. iii. 1861, p. 141.
16 See Dr. Gunther ou tins genus, in ‘Proc. Zoolog. Soc.’ 1868, p. 232.
CiiAr, XII.
FISHES.
11
* ig' 30' I’lecostoinus barbatus. Upper figure, head of male ; lower figure, female.
12
SEXUAL SELECTION.
Part II.
male, which are absent in the female. These tentacles are prolongations of the true skin, and therefore are not homologous with the stiff hairs of the former species; but it can hardly be doubted that both serve the same purpose. What this purpose may be it is difficult to conjecture ; ornament does not here seem probable, but we can hardly suppose that stiff hairs and flexible fila- ments can be useful in any ordinary way to the males alone. The Monacantlius scopag, which was shewn to me in the British Museum by Dr. Gunther, presents a nearly analogous case. The male has a cluster of stiff, straight spines, like those of a comb, on the sides of the tail ; and these in a specimen six inches long were nearly an inch and a half in length ; the female has on the same place a cluster of bristles, which may be compared with those of a tooth-brush. In another species, the M. peronii, the male has a brush like that possessed by the female of the last species, w'hilst the sides of the tail in the female are smooth. In some other species the same part of the tail can be perceived to be a little roughened in the male and perfectly smooth in the female ; and lastly in others, both sexes have smooth sides. In that strange monster, the Chimasra monstrosa, the male has a hook- shaped bone on the top of the head, directed forwards, with its rounded end covered with sharp spines ; in the female “ this crown is altogether absent,” but what its use may be is utterly unknown.17
The structures as yet referred to are permanent in the male after he has arrived at maturity ; but with some Blennies and in another allied genus 18 a crest is deve- loped on the head of the male only during the breed-
U F. Buckland, in 1 Land and Water,’ July, 1868, p. 377, with a figure.
18 Dr. Giintlier, £ Catalogue of Fishes,’ vol. iii. p. 221 and 240.
chap. XII.
FISHES.
13
lng-season, and their bodies at the same time become ’ftore brightly-coloured. There can be little doubt that this crest serves as a temporary sexual ornament, for the female does not exhibit a trace of it. In other species °f the same genus both sexes possess a crest, and in at least one species neither sex is thus provided. In this °ase and in that of the Monacantlius, we have good in- stances to how great an extent the sexual characters of closely-allied forms may differ. In many of the Chro- rQ1'(lEe, for instance in Geophagus and especially in Cichla, the males, as I hear from Professor Agassiz, 1S have a con- spicuous protuberance on the forehead, which is wholly Wanting in the females and in the young males. Pro- fessor Agassiz adds, “ I have often observed these fishes at the time of spawning when the protuberance is “largest, and at other seasons when it is totally wanting ‘ and the two sexes shew no difference whatever in the ‘outline of the profile of the head. I never could 'ascertain that it subserves any special function, and ‘the Indians on the Amazon know nothing about its use.” These protuberances in their periodical appear- ailce resemble the fleshy caruncles on the heads of cer- tain birds ; but whether they serve as ornaments must remain at present doubtful.
f'he males of those fishes, which differ permanently in colour from the females, often become more brilliant, as hear from Professor Agassiz and Dr. Gunther, during 1(1 breeding-season. This is likewise the case with a Multitude of fishes, the sexes of which at all other seasons of the year are identical in colour. The tench, l0ach, and perch may he given as instances. The male salmon at this season is “ marked on the cheeks with
29ft66 a^S0 ‘ ^ Jolmiey in Brazil,’ by Prof, and Mrs. Agassiz, 1868.
14
SEXUAL SELECTION.
Part II.
“ orange-coloured stripes, which give it the appearance “ of a Labrus, and the body partakes of a golden-orange “ tinge. The females are dark in colour, and are com- “ monly called black-fish.*’ 20 An analogous and even greater change takes place with the Salmo eriox or bull- trout ; the males of the char (S. umbla ) are likewise at this season rather brighter in colour than the females.21 The colours of the pike (Esox reticulatus) of the United States, especially of the male, become, during the breeding-season, exceedingly intense, brilliant, and iri- descent.22 Another striking instance out of many is afforded by the male stickleback (Gasterosteus leiurus), which is described by Mr. Warington,23 as being then “ beautiful beyond description.” The back and eyes of the female are simply brown, and the belly white. The eyes of the male, on the other hand, are “of the most “ splendid green, having a metallic lustre like the “ green feathers of some humming-birds. The throat “ and belly are of a bright crimson, the back of an “ ashy-green, and the whole fish appears as though it “ were somewhat translucent and glowed with an in- “ ternal incandescence.” After the breeding-season these colours all change, the throat and belly become of a paler red, the back more green, and the glowing tints subside.
That with fishes there exists some close relation between their colours and their sexual functions we can clearly see : — firstly, from the adult males of certain species being differently coloured from the females, and often much more brilliantly ; — secondly, from these same
a> Yarrell, ‘British Fishes,’ vol. ii. lS3ti, p. 10, 12, K5.
W. Thompson, in ‘ Annals and Mag. of Nat. History,’ vol. vi. 1841, p. 440.
32 ‘ The American Agriculturist,’ 1S68, p. 100.
23 ‘ Annals and Mag. of Nat. Hist.’ Oct. 1852.
Chap, xil.
FISHES.
15
^ales, whilst immature, resembling the mature females ;
uud, lastly, from the males, even of those species "liieh at ali other times of the year are identical in colour with the females, often acquiring brilliant tints during the spawning-season. We know that the males are ardent in their courtship and sometimes fight despe- rately together. If we may assume that the females aave the power of exerting a choice and of selecting the |lloro highly-ornamented males, all the above facts occorne intelligible through the principle of sexual election. On the other hand, if the females luxbi- f Hally deposited and left their ova to be fertilised by first male which chanced to approach, this fact "°uld be fatal to the efficiency of sexual selection; for there could be no choice of a partner. But, as far known, the female never willingly spawns except the close presence of a male, and the male never e,'tilises the ova except in the close presence of a female. It is obviously difficult to obtain direct avidence with respect to female fishes selecting ‘eir partners. An excellent observer,24 who carefully Htched the spawning of minnows ( Cyprinus phoxinus), Remarks that owing to the males, which were ten times numerous as the females, crowding closely round 1( Ie|u> he could “ speak only doubtfully on their opera- t( tions. When a female came among a number of uiales they immediately pursued her; if she was not „ lfca<1y for shedding her spawn, she made a precipitate t letreat ; but if she was ready, she came boldly in <( araong them, and was immediately pressed closely by „ a. llJale on each side ; and when they had been in that t, ‘slfuatiou a short time, were superseded by other two, " 10 wedged themselves in between them and the
24 Loudon’s ‘Mag. of Nat. Hist.’ vol. v. 1832, p. 681..
16
SEXUAL SELECTION.
Paet II.
“ female, who appeared to treat all her lovers with “the same kindness.” Notwithstanding this last state- ment, I cannot, from the several previous considera- tions, give up the belief that the males which are the most attractive to the females, from their brighter colours or other ornaments, are commonly preferred by them ; and that the males have thus been rendered more beautiful in the course of ages.
We have next to inquire whether this view can be extended, through the law of the equal transmission of characters to both sexes, to those groups in which the males and females are brilliant in the same or nearly the same degree and manner. In such a genus as Labrus, which includes some of the most splendid fishes in the world, for instance, the Peacock Labrus (L. joavo), described,25 with pardonable exaggeration, as formed of polished scales of gold encrusting lapis- lazuli, rubies, sapphires, emeralds and amethysts, we may, with much probability, accept this belief; for we have seen that the sexes in at least one species differ greatly in colour. With some fishes, as with many of the lowest animals, splendid colours may be the direct result of the nature of their tissues and of the surround- ing conditions, without any aid from selection. The gold-fish (Cyprinus auratus ), judging from the analogy of the golden variety of the common carp, is, perhaps, a ease in point, as it may owe its splendid colours to a single abrupt variation, due to the conditions to which this fish has been subjected under confinement. It is, however, more probable that these colours have been intensified through artificial selection, as this spe- cies has been carefully bred in China from a remote
25 Bory de Saint Vincent, in ‘Diet. Class. d’Hist, Nat.’ torn.ix. ISiU. p. 151.
Cha,p, yjj
FISHES.
17
period.26 Under natural conditions it does not seem Probable that beings so highly organised as fishes, and which live under such complex relations, should become brilliantly coloured without suffering some evil or re- viving some benefit from so great a change, and conse- •prently without the intervention of natural selection.
^ hat, then, must we conclude in regard to the many ^hes, both sexes of which are splendidly coloured? br. Wallace27 believes that the species which frequent reefs, where corals and other brightly-coloured organisms abound, are briglitly coloured in order to escape detec- tion by their enemies ; but according to my recollection they were thus rendered highly conspicuous. In the fresh-waters of the Tropics there are no brilliantly- coloured corals or other organisms for the fishes to resemble ; yet many species in the Amazons arc beau- tr fully coloured, and many of the carnivorous Cypri- I'ldse in India are ornamented with “ bright longitu- dinal lines of various tints.” 28 Mr. M‘Clelland, in describing these fishes goes so far as to suppose that the peculiar brilliancy of their colours ” serves as “a ‘‘better mark for king-fishers, terns, and other birds "inch are destined to keep the number of these fishes Ul check ; ” but at the present day few naturalists will
Y ' .Owing to some remarks on this sutyect, made in my work ‘ On the Cation 0f Animals under Domestication,’ Mr. \V. F. Mayers an . ese kotes and Queries,’ Aug. 1868, p. 123) has searched the ^ cient Chinese encyclopedias. He limls that gold-fish were first Ann’'11 ocm^hement during the Sung Dynasty, which commenced it 1 ’ . ' tu the year 1129 these fishes abounded. In another place “cT Sa^ s‘ni'° the year 1548 there has been “ produced at llang- u Ww.a variety called the fire fish, from its intensely red colour. It “ o il!?’versiaUy admired, and there is not a household where it is not V i^a^e<b ‘u rivalry as to Us colour, and as a source of profit.” a ( Westminster Review,’ July, 1867, p. 7. v ; Indian Cypriuidte,” by Mr. J. M'Clellaud, ‘ Asiatic Researches,’ ■ s«. part ii 1839, p. 230.
VOL.Xl. c
18
SEXUAL SELECTION.
Part II.
admit that any animal has been made conspicuous as an aid to its own destruction. It is possible that certain fishes may have been rendered conspicuous in order to warn birds and beasts of prey (as explained when treat- ing of caterpillars) that they were unpalatable; but it is not, I believe, known that any fish, at least any fresh- water fish, is rejected from being distasteful to fish- devouring animals. On the whole, the roost probable view in regard to the fishes, of which both sexes are brilliantly coloured, is that their colours have been acquired by the males as a sexual ornament, and have been transferred in an equal or nearly equal degree to the other sex.
We have now to consider whether, when the male differs in a marked manner from the female in colour or in other ornaments, be alone has been modified, with the variations inherited only by his male offspring ; or whether the female has been specially modified and rendered inconspicuous for the sake of protection, such modifications being inherited only by the females. It is impossible to doubt that colour has been acquired by many fishes as a protection: no one can behold the speckled upper surface of a flounder, and overlook its resemblance to the sandy bed of the sea on which it lives. One of the most striking instances ever recorded of an animal gaining protection by its colour (as far as can he judged in preserved specimens) and by its form, is that given by Dr. Gunther28 of a pipe- fish, which, with its reddish streaming filaments, is hardly distinguishable from the sea-weed to which it clings with its prehensile tail. But the question now under consideration is whether the females alone have been modified for this object. Fishes offer valuable
29 ‘Proc. Zoolog. Soc.’ 1865, p. 327, pi. xiv. and xv.
ClIAP. XII.
FISHES.
19
evidence on this head. We can see that one sex will n°t be modified through natural selection for the sake of protection more than the other, supposing both to Vai'y > unless one sex is exposed for a longer period to danger, or has less power of escaping from such danger than the other sex ; and it does not appear that "ith fishes the sexes differ in these respects. As far as there is any difference, the males, from being generally smaller size, and from wandering more about, are exposed to greater danger than the females ; and yet, 'vken the sexes differ, the males are almost always the ^ost conspicuously coloured. The ova are fertilised Bnmediately after being deposited, and when this pro- Cess lasts for several days, as in the case of the salmon,30 the female, during the whole time, is attended by the n'ale- After the ova are fertilised they are, in most cases, left unprotected by both parents, so that the males and females, as far as oviposition is concerned, are equally exposed to danger, and both are equally 11,1 P°i' taut for the production of fertile ova ; consequently the more or less brightly-coloured individuals of either Sex would be equally liable to be destroyed or pre- Sei'ved, and both would have an equal infiuenco on the c°l°urs of their offspring or the race.
Certain fishes, belonging to several families, make llests ; and some of these fishes take care of their •°Ung when hatched. Both sexes of the brightly- coloured Crenilabrus massa and melons work together in nilding their nests with sea-weed, shells, &c.31 But the tt'ales 0f certajn fis]ieg (|0 ail the work, and afterwards d ve exclusive charge of the young. This is the case
m Yarrell> ‘ British Fishes,’ vol. ii. p. 11. e . '“-CC01'ding to the observations of M. Gerbe; see Gunther’s ‘Ke- °f Zoolog. Literature,’ 1865, p. 194.
20
SEXUAL SELECTION.
Pap.t II.
with the dull-coloured gobies,32 in which the sexes are not known to differ in colour, and likewise with the sticklebacks (Gasterosteus), in which the males become brilliantly coloured during the spawning-season. The male of the smooth-tailed stickleback (G. leiurus ) per- forms during a long time the duties of a nurse with exemplary care and vigilance, and is continually employed in gently leading hack the young to the nest when they stray too far. He courageously drives away all enemies, including the females of his own species. It would indeed be no small relief to the male if the female, after depositing her eggs, were immediately devoured by some enemy, for he is forced incessantly to dx-ive her from the nest.33
The males of certain other fishes inhabiting South America and Ceylon, and belonging to two distinct orders, have the extraordinary habit of hatching the eggs laid by the females within their mouths or branchial cavities.84 With the Amazonian species which follow this habit, the males, as I am informed by the kindness of Professor Agassiz, “not only are generally brighter “ than the females, hut 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 deve- loped ou the forehead of the males during the breeding- season. W ith the various species of Chrom ids, as Pro- lessor Agassiz likewise informs me, sexual differences
Cuvier, ‘ Eegne Atiimal,’ vol. ii. 1829, p. 212.
:!;i See Mr. Warington’s most interesting description of the habits of the Gasterosteus leiurus, in ‘Annals anil Mag. of Nat. Hist.’ November, 1855.
84 Prof. Wyman, in ‘Proc. Boston Soe. of Nat. Hist.’ Sept. 15, 1857. Also W. Turner, in ‘Journal of Anatomy and Pliys.’ Nov. 1, 1866, p. 78. Dr. Gunther has likewise described other cases.
Chap. xii.
FISHES.
21
111 colour may be observed, “ whether they lay their ' eggs in the water among aquatic plants, or deposit “ them in holes, leaving them to come out without “ further care, or build shallow nests in the river-mud, over which they sit, as our Promotis does. It ought “ also to be observed that these sitters are among the brightest species in their respective families ; tor ‘ instance, Ilygrogonus is bright green, with large black ocelli, encircled with the most brilliant red.
^ hether with all the species of Chromids it is the male aione which sits on the eggs is not known. It is, however, manifest that the fact of the eggs being pro- moted or unprotected, has bad little or no influence on hho differences in colour between the sexes. It is fur- ther manifest, in all the cases in which the males take delusive charge of the nests and young, that the destruction of the brighter-coloured males would be far m°re influential on the character of the race, than the destruction of the brighter-coloured females; for the death of the male during the period of incubation or nursing would entail the death of the young, so that ihese could not inherit bis peculiarities; yet, in many °f these very cases the males are more conspicuously c‘°loured than the females.
In most of the Lophobranchii (Pipe-fish, Hippo- eaurpi, &c.) the males have either marsupial sacks or hemispherical depressions on the abdomen, in which f le ova laid by the female are batched. The males a 80 shew great attachment to their young.® The r?Xes do not commonly differ much in colour ; hut Dr. -* iinfher believes that the male Hippocampi are rather ' rigliter than the females. The genus Solenostoma,
Yarrell, ‘ Hist, of British Fishes,’ vol, ii. 1836, p. 329, 338.
35
22
SEXUAL SELECTION.
Part II.
however, offers a very curious exceptional case,36 for the female is much more vividly coloured and spotted than the male, and she alone has a marsupial sack and hatches the eggs; so that the female of Solenostoma differs from all the other Lophobranekii in this latter respect, and from almost all other fishes, in being more brightly coloured than the male. It is improbable that this remarkable double inversion of character in the female should be an accidental coincidence. As the males of several fishes which take exclusive charge of the eggs and young are more brightly coloured than the females, and as here the female Solenostoma takes the same charge and is brighter than the male, it might be argued that the conspicuous colours of the sex which is the most important of the turn for the welfare of the offspring must serve, in some manner, as a protection. But from the multitude of fishes, the males of which are either permanently or periodically brighter than the females, but whose life is not at all more important than that of the female for the welfare of the species, this view can hardly be maintained. When we treat of birds we shall meet with analogous cases in which there has been a complete inversion of the usual attri- butes of the two sexes, and we shall then give what appears to be the probable explanation, namely, that the males have selected the more attractive females, instead of the latter having selected, in accordance with the usual rule throughout the animal kingdom, the more attractive males.
On the whole we may conclude, that with most fishes, in which the sexes differ in colour or in other orna-
36 Dr. G iinther, since publishing an account of this species in ‘The Fishes of Zanzibar,’ by Col. Playfair, 1866, p. 137, lias re-examined the specimens, and has given me the above information.
Chap. XII.
FISHES.
23
Cental characters, the males originally varied, with their '’aviations transmitted to the same sex, and accumulated through sexual selection by attracting or exciting the females. In many cases, however, such characters have beeu transferred, either partially or completely, to the females. In other cases, again, both sexes have been Coloured alike for the sake of protection; but in no instance does it appear that the female alone has had her colours or other characters specially modified lor this purpose.
-t he last point which need be noticed is that in many Parts of the world fishes are known to make peculiar Noises, which are described in some cases as being Musical. Very little has been ascertained with respect to the means by which such sounds are produced, and evei1 less about their purpose. The drumming of the Urubrinas in the European seas is said to be audible h°in a depth of twenty fathoms. The fishermen ol 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.” 37 If this statement is trustworthy, we have an instance in this, the lowest class of the Vertebrata, of what we shall find prevailing throughout the other vertebrate classes, au'l which prevails, as we have already seen, with insects and spiders ; namely, that vocal and instru- mental sounds so commonly serve as a love-call or as a love-charm, that the power of producing them was probably first developed in connection with the propa- gation of the species.
37 Thu Rev. C. Kingsley, in ‘Nature,’ May, 1870, p. i0.
24
SEXUAL SELECTION.
I’art ii-
Amphibians.
Urodela. — First for the tailed amphibians. The sexes of salamanders or newts often differ much both in colour and structure. In some species prehensile claws are developed on the fore-legs of the males during the breeding-season; and at this season in the male Triton palmipes the hind-feet are provided with a swimming web, which is almost completely absorbed during the winter; so that their feet then
jig. .11. I riton cristatus (half natural size, from Bell’s ‘British Reptiles’), ppei figure, male during the breeding-season; lower figure, female.
resemble those of the female.38 This structure no doubt aids the male in his eager search and pursuit of the female. With our common newts ( Triton punctatus and cristatus ) a deep, much-indented (west is developed along the back and tail of the male during the breed- ing-season, being absorbed during the winter. It is not furnished, as Mr. St. George Mivart informs me,
3S Bell, ‘ History of British Beptiles,’ 2nd edit. 1849, p. 156-159.
C"AI>. XII.
AMPHIBIANS.
25
"’ith muscles, and therefore cannot be used for loco- motion. As during the season of courtship it becomes 0<%ed with bright colours, it serves, there can hardly 30 a doubt, as a masculine ornament. In many species the body presents strongly contrasted, though lurid tints ; and these become more vivid during the J1'eedi ng-season. The male, for instance, of our com- mon little newt ( Triton pundatus ) is “ brownish-grey c ahove, passing into yellow beneath, which in the K sI»ing becomes a rich bright orange, marked every- 1 "’here with round dark spots.” The edge of the crest a 80 is then tipped with bright red or violet. The eiaale is usually of a yellowish-brown colour with scattered brown dots; and the lower surface is often cbute plain.39 The young are obscurely tinted. The 0Va are fertilised during the act of deposition and are n°t subsequently tended by either parent. We “my therefore conclude that the males acquired their i°ngly-markcd colours and ornamental appendages l0Ugh sexual selection ; these being transmitted either Ue male offspring alone or to both sexes.
^Q^nuTa 01 Batrachia. — With many frogs and toads ^ 6 colours evidently serve as a protection, such as 6 bright green tints of tree-frogs and the obscure 1 fled shades of many terrestrial species. The most tp k’Cuously coloured toad which I ever saw, namely 0j.e ^ lrynisGus nigricans ,10 had the whole upper surface an l *e k°cly as black as ink, with the soles of the feet v . ?ai'^s the abdomen spotted with the brightest gra U 10n’ ^ crawled about the bare sandy or open
‘ sy plains of La Plata under a scorching sun, and
« ibid. p. 146, 151.
Mr ,°olo§y of the Voyage of the “ Beagle,” ’ 1843. “ Reptiles, ” by ' ■Deu> p. 49.
26
SEXUAL SELECTION.
Part II.
could not fail to catcli the eye of every passing creature. These colours may be beneficial by making this toad known to all birds of prey as a nauseous mouthful ; for it is familiar to every one that these animals emit a poisonous secretion, which causes the mouth of a dog to froth, as if attacked by hydrophobia. 1 was the more struck with the conspicuous colours of this toad, as close by I found a lizard ( Prodotreius multimaculatus) which, when frightened, flattened its body, closed its eyes, and then from its mottled tints could hardly be distinguishable from the surrounding sand.
With respect to sexual differences of colour, Ur. Gun- ther knows of no striking instance 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 Ur. Gunther know of any striking difference in external structure between the sexes, excepting the prominences which become developed during the breed- ing-season on the front-legs of the male, by which lie is enabled to hold the female. The Megalojphrys mon- tana'" (fig. 82) offers the best case of a certain amount of structural difference between the sexes; for in the male the tip of the nose and the eyelids are produced into triangular flaps of skin, and there is a little black tubercle on the back — characters which are absent, or only feebly developed, in the females. It is surprising that frogs and toads should not have acquired more strongly-marked sexual differences ; for though cold- blooded, their passions are strong. Ur. Gunther informs me that he has several times found an unfortunate female toad dead and smothered from having been so closely embraced by three or four males.
41 ‘ The Beptiles of India,’ by Dr. A. Gunther, Bay Soe. 1864, p. 413.
C«AP. XII.
AMriilBIANS.
27
f hese animals, however, offer one interesting sexual merenee, namely in the musical powers possessed by males ; hut to speak of music, when applied to the ' Mordant and overwhelming sounds emitted by male JU H-frogs and some other species, seems, according to °Ur taste, a singularly inappropriate expression. Never- theless certain frogs sing in a decidedly pleasing man- aer- Near llio de Janeiro I used often to sit in the ev’ening to listen to a number of little Hylrn, which,
32. Megalophrys montana. The two left-hand figures, the male ; the two right-hand figures, the female.
j?Pl(,hed on blades of grass close to the water, sent U1th sweet chirping notes in harmony. The various l°UQ(is are emitted chiefly by the males during the /’^'ding-season, as in the case of the croaking of our c‘°ttmion frog.42 In accordance with this fact the vocal lagans of the males are more highly developed than °Se of the females. In some genera the males alone
42 Belt, 1 History of British. Beptiles,’ 184!), p. 93.
28
SEXUAL SELECTION.
Part II.
are provided with sacs which open into the larynx.43 For instance, in the edible frog (liana eseulenfa ) “the “ sacs are peculiar to the males, and become, when filled “ with air in the act of croaking, large globular blad- “ ders, standing out, one on each side of the head, near “ the corners of the mouth.” The croak of the male is thus rendered exceedingly powerful ; whilst that of the female is only a slight groaning noise.44 The vocal organs differ considerably in structure in the several genera of the family ; and their development in all cases may be attributed to sexual selection.
Eeptiles.
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 ( Ohrysemys picta) has claws on its front-feet twice as long as those of the female ; and these are used when the sexes unite.43 With the huge tortoise of the Gala- pagos 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 he heard at the dis- tance of more than a hundred yards ; the female, on the other hand, never uses her voice.46
Crocodilia. — The sexes apparently do not differ in
43 J- Bishop, in ‘ Todd’s Cyclop, of Anat. and Phys.’ vol. iv. p. 1503.
44 Bell, ibid. p. 112-114.
45 Mr. C. J. Maynard, 1 The American Naturalist,’ Dec. 1869, p. 555.
46 See mv ‘Journal of Researches during the Voyage of the Beagle,” ’ 18.45, p. 384.
XII.
REPTILES.
29
colour ; nor do I know tkat the males fight together, though this is probable, for some kinds make a prodi- 8’ous display before the females. Bartram 47 describes male alligator as striving to win the female by splashing and roaring in the midst of a lagoon, “ swollen (( t° an extent ready to burst, with his head and tail {£ fitted up, 116 spins or twirls round on the surface of tlle water, like an Indian chief rehearsing his feats . °f War.” During the season of love, a musky odour Js emitted by the submaxillary glands ot the crocodile, llt|d pervades their haunts.48
^phidia. — I have little to say about Snakes. Dr. ■fintlier informs me that the males are always smaller man the females, and generally have longer and slen- <erer tails; but he knows of no other difference in eternal structure. In regard to colour, Dr. Gunther ?au almost always distinguish the male from the female :v ll4s more strongly-pronounced tints ; thus the black ''•gzag hand on the back of the male English viper is m°re distinctly defined than in the female. The differ- !?lCe is much plainer iu the Rattle-snakes of N. America, p'e lnale of which, as the keeper in the Zoological mvdens shewed me, can instantly be distinguished from le female by having more lurid yellow about its whole 0cly- In S. Africa the Bucephalus capensis presents an ‘^alogous difference, for the female “ is never so fully variegated with yellow on the sides, as the male.” 43 le male of the Indian Dipsos cynodon, on the other
hand.
is blackish-brown, with the belly partly black,
I , '-'‘uivuvicjii ui w u ujhi J j
mst tlie female is reddish or yellowish-olive with the } either uniform yellowish or marbled with black.
■13 ‘T'avels through Carolina,’ &c., 1791, p. 128.
« ‘ Anatomy of Vertebrates,’ vol. i. 1866, p. 615.
hlr Andrew Smith, Zoolog. of S. Africa : lteptilia,’ 1819, pi. X.
30
SEXUAL SELECTION.
Part II.
In the Tragojps disbar of the same country, the male is bright green, and the female bronze-coloured.50 No doubt the colours of some snakes serve as a protection, as the green tints of tree-snakes and the various mottled shades of the specips which live in sandy places; but it is doubtful whether the colours of many kinds, for instance of the common English snake or viper, serve to conceal them ; and this is still more doubtful with the many foreign species which are coloured with ex- treme elegance.
During the breeding-season their anal scent-glands are in active function;51 and so it is with the same glands in lizards, and as we have seen with the sub- maxillary glands of crocodiles. As the males of most animals search for the females, these odoriferous glands probably serve to excite or charm the female, rather than to guide her to the spot where the male may be found.5'1 Male snakes, though appearing so sluggish, are amorous ; for many have been observed crowding round the same female, and even round the dead body of a female. They are not known to fight together from rivalry. Their intellectual powers are higher than might have been anticipated. An excellent observer in Ceylon, Mr. E. Layard,53 saw a Cobra thrust its head through a narrow hole and swallow a toad. “With
50 Dr. A. Gunther, ‘ Reptiles of British India,’ Ray Soc. 1861, p. 304, 308.
51 Oweu, ‘Anatomy of Vertebrates,’ vol. i. 18GG, p. 615,
52 The celebrated botanist Schleideu incidently remarks (‘Uehor den Darwinism™: Unsure Zeit,’ I860, s. 269), that Rattle- snakes use their rattles as a sexual call, by which the two sexes find each other. I do not know whether this suggestion rests on any direct observations- These snakes pair in the Zoological Gardens, hut the keepers have never observed that they use their mttles at tin's season more than at any other.
53 “ Rumbles in Ceylon,” 1 Annals and Mag. of Nat. Hist.’ 2nd series, vol. ix. 1852, p. 333.
C,'AP. XII.
BEPTILES.
31
( this incumbrance lie could not withdraw himself ; (( finding this, he reluctantly disgorged the precious morsel, which began to more off; this was too much () ^<n' snalce philosophy to bear, and the toad was again seized, and again was the snake, after violent efforts
*C j O t
( Cl) escape, compelled to part with its prey. This time, (< ‘°wever, a lesson had been learnt, and the toad was (( s,'iz(-d by one leg, withdrawn, and then swallowed in ‘ d'iuinph.”
It does not, however, follow because snakes have s< 1,110 reasoning power and strong passions, that they s lonkl likewise be endowed with sufficient taste to j1 la'r° brilliant colours in their partners, so as to ead to the adornment of the species through sexual election. Nevertheless it is difficult to account in ilriy other manner for the extreme beauty of certain sl>°eies ; f01. instance, of the coral-snakes of S. America, llch are of a rich red with black and yellow transverse ^mds, j Well remember how much surprise I felt at le beauty of the first coral-snake which I saw gliding 'lCross a path in Brazil. Snakes coloured in this peculiar manner, as Mr. Wallace states on the authority of Dr. unther m are found nowhere else in the world except k. America, and here no less than four genera occur. (j. e. these, Elaps, is venomous ; a second and widely- lstmct genus is doubtfully venomous, and the two others 110 quite harmless. The species belonging to these dis- *7 genera inhabit the same districts, and are so like <t .°tker, that no one “ but a naturalist would distin- the harmless from the poisonous kinds.” Hence, I , r’ Wallace believes, the innocuous kinds have pro- . y ncquired their colours as a projection, on the 1mciple of imitation ; for they would naturally be
54 ‘Westminster Beview,’ July 1st, 1867, p. 32.
32
SEXUAL SELECTION.
Part IT-
thought dangerous by their enemies. The cause, how- ever, of the bright colours of the venomous Elaps remains to be explained, and this may perhaps be sexual selection.
Lacertilia. — The males of some, probably of many kinds of lizards light together from rivalry. Thus the arboreal Anolis cristatellus of S. America is extremely pugnacious: “During the spring and early part of the “ summer, two adult males rarely meet without a con- “ test. On first seeing one another, they nod their heads i “ up and down three or four times, at the same time “ expanding the frill or pouch beneath the throat ; their “ eyes glisten with rage, and after waving their tails I “ from side to side for a few seconds, as if to gather “ energy, they dart at each other furiously, rolling over “ and over, and holding firmly with their teeth. The “ conflict generally ends in one of the combatants losing “ his tail, which is often devoured by the victor.” The male of this species is considerably larger than the fe- ! male;65 and this, as far as Dr. Giinther has been able to ascertain, is the general rule with lizards of all kinds.
The sexes often differ greatly in various external characters. The male of the above-mentioned Anoiis 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 GojAiotis ceylanica, the female possesses a dorsal crest, though much less developed than in the male; and so it is, as Dr. Gunther informs me, with the females of many Iguanas, Chameleons and other lizards. In some species, however, the crest is equally developed in both sexes, as in the Iguana tubereulata. In the genus
55 Mr. N. L. Austen kept these animals alive for a considerable time see ‘ Land and Water/ J uly, 1867, p. 9.
Chap. xii.
EEPTILES.
38
O' ,
itana, the males alone are furnished with a large hi'oat-pouch (fig. 33), which can be folded up like a an» and is coloured blue, black, and red; but these sPWdid colours are exhibited only during the pairing- season. The female does not possess ei'en a rudiment ? tins appendage. In the Anolis cristatellus , acoord- ln8 to Mr. Austen, the throat-pouch, which is bright red marbled with yellow, is present, though in a rudi- laj-ntal condition, in the female. Again, in certain nther lizards, both sexes are equally well provided with . 1r°at-pouches. Here, as ln so many previous cases,
]Ve See with species be- gging to the same group, e same character con- 1 ed to the males, or more a,Sely developed in the Itlales than in the females,
?r equally developed in ’0th sexes. The little li- ^auls of the genus Draco,
'. "eh glide through the air on their rib-supported para- j mtes> and which in the beauty of their colours baffle escription; are furnished with skiuny appendages to the •roat, “lifie the wattles of gallinaceous birds.” These ecome erected when the animal is excited. They occur 111 both sexes, but are best developed in the male when ari'ived at maturity, at which age the middle appendage 8 sometimes twice as long as the head. Most of the sPecie8 likewise have a low crest running along the ! and this is much more developed in the full- hr°wn males, than in the females or young males."’6
Fig. 33. Sitana minor. Male, with the gular pouch expanded (from Gunther’s ‘Rep- tiles of India’).
atln these statements and quotations, in regard to Cophotis, Sitana raco, as well as the following facts in regard to Ceratophora, are VOL. xi. D
34
SEXUAL SELECTION.
Part II.
There are other and much more remarkable dif- ferences between the sexes of certain lizards. The male of Ccratophora aspera bears on the extremity of his snout an appendage half as long as the head. It is cylindrical, covered with scales, flexible, and appa- rently capable of erection : in the female it is quite rudimental. In a second species of the same genus a terminal scale forms a minute horn on the summit of the flexible appendage ; and in a third species (C- Stocldartii, fig. 34 ) the whole appendage is converted
into a horn, which is usually of a white colour, but as- sumes 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 is of quite minute size in the female and in the young. These appen- dages, as Dr. Gunther has remarked to me, may be compared with the combs of «g. 34. ceratophora stoddartii. upper gallinaceous birds, and appa-
figure, mule; luwer figure, female 6 fl
ently serve as ornaments.
In the genus Chamaeleon we come to the climax of difference between the sexes. The upper part of the slcull of the male C. Ufurcus (fig. 35), an inhabitant of Madagascar, is produced into two great, solid, bony pro- jections, covered with scales like the rest of the head ; and of this wonderful modification of structure the female exhibits only a rudiment. Again, in Cliamieleon OivenU (%. 36), from the West Coast of Africa, the male bears
taken from Dr. Gunther’s magnificent work on the ‘ Eeptiles of British India,’ Kay Soc. 18G4, p. 122, 130, 135.
ClJAl. XII.
REPTILES.
35
011 his snout and forehead three curious horns, of which *he female has not a trace. These horns consist of an excrescence of bone covered with a smooth sheath, Arming part of the general integuments of the body, so that they are identical in structure with those of a
35. Chameleon bifurcus. Upper figure, male; lower figure, female,.
foill, goat, or other sheath-horned ruminant. Although le three horns differ so much in appearance from *e two great prolongations of the skull in C. bifurcus, ''e can hardly doubt that they serve the same general 1 arpose in the economy of these two animals. The
36
SEXUAL SELECTION.
Pabt II-
first conjecture which will occur to every one is that they are used by the males for fighting together ; but Dr. Gunther, to whom I am indebted for the foregoing details, does not believe that such peacable crea- tures would ever become pugnacious. Hence we are
with the previously-mentioned Cophotis and with the Acantliodactijlus capensis of S. Africa. In a Cordylus of the latter country, the male is either much redder or greener than the female. In the Indian Calotes nigri- labris there is a greater difference in colour between the sexes ; the lips also of the male are black, whilst those of the female are green. In our common little viviparous lizard ( Zootoca vivipara ) “ the under “ side of the body and base of the tail in the male arc “ bright orange, spotted with black; in the female “ these parts are pale greyish-green without spots.”4' We have seen that the males alone of Sitana possess a
driven to infer that these almost mon- strous deviations of structure serve as masculine orna- ments.
Fig. 36. Chameleon Owenii. Upper figure, male ; lower figure, female.
With many kinds of lizards, the sexes differ slightly in co- lour, the tints and stripes of the males being brighter and more distinctly de- fined than in the females. This, for instance, is the case
57 Bell, ‘ History of British Bepliles,’ 2nd edit. 1S49, p. 40.
C|up. xn.
REPTILES.
37
throat-pouch ; and this is splendidly tinted with blue,
J ar'b, and red. In the Proctotretus tenuis of Chile the Illide alone is marked with spots of blue, green, and CoPpery-red.68 I collected in S. America fourteen species of this genus, and though I neglected to record sexes, I observed that certain individuals alone were ‘"orbed with emcrald-like green spots, whilst others ‘acl orange-coloured gorges ; and these in both cases n° doubt were the males.
11 tlie foregoing species, the males are more brightly coloured than the females, but with many lizards both ^Xes are coloured in the same elegant or even magni- Cei‘t manner ; and there is no reason to suppose that ^ch conspicuous colours are protective. With some 1Zards, however, the green tints no doubt serve for C0lmealnient ; and an instance has already been inci- 'entjy gjven 0£ one Specieg 0f Proctotretus which resembles the sand on which it lives. On the
closely
I ^°lo 've may conclude with tolerable safety that the dutiful colours of many lizards, as well as various appendages and other strange modifications of structure, j.dV° been gained by the males through sexual selection °r the sake of ornament, and have been transmitted P er to their male offspring alone or to both sexes. .^-Xual selection, indeed, seems to have played almost as Important a part, with reptiles as with birds. Put the ?s conspicuous colours of the females in comparison yj those of the males cannot be accounted for, as * ' " allace believes to be the case with birds, by the Posure of the females to danger during incubation.
aS pi ^
Re))ti|'.)r,Proc,°trenis see -Zoology of the Voyage of the “Beagle:” of ^ ,c 8’. by Mr. Bell, p. 8. For tl.e Lizards of S, Africa, see ‘ Zoology lojh ‘,lca : Reptiles,’ by Sir Andrew Smith, pi. 25 and 39. For the '-“lotos, see ‘ Reptiles of British India,’ by Dr. Gunther, p. 143.
38
SEXUAL SELECTION.
Part It
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 ornaments by the males.
Secondary sexual characters are more diversified and conspicuous in birds, though not perhaps entailing more important changes of structure, than iu any other class of animals. I shall, therefore, treat the subject at con- siderable length. Male birds sometimes, though rarely, possess special weapons for fighting with each other. They charm the females by vocal or instrumental music of the most varied kinds. They are ornamented by all sorts of combs, wattles, protuberances, horns, air- distended sacs, topknots, naked shafts, plumes and lengthened feathers gracefully springing from all parts of the body. The beak and naked skin about the head, and the feathers are often gorgeously coloured. The males sometimes pay their court by dancing, or by fan- tastic antics performed either on the ground or in the air. Iu one instance, at least, the male emits a musky odour which wTe may suppose serves to charm or excite the female ; for that excellent observer, Mr. Ramsay,1 says of the Australian musk-duck (Biziura lobata ) that “ the “ smell which the male emits during the summer “ months is confined to that sex, and iu some indi- “ viduals is retained throughout the year ; I have never
1 ‘Ibis,’ vol. iff, (new series) 1867, p. 414.
Chap. XIII.
BIRDS.
39
even in the breeding-season, shot a female which had “ any smell of musk.” So powerful is this odour during the pairing-season, that it can be detected long bcfoie the bird can be seen.2 On the whole, birds appear to he the most msthetic of all animals, excepting ot course lna,i, and they have nearly the same taste for the beau- tiful as we have. This is shewn by our enjoyment of the singing of birds, and by our women, both civilised aud savage, decking their heads with borrowed plumes, and using gems which are hardly more brilliantly coloured than the naked skin and wattles of certain
birds.
Before treating of the characters with which we are here more particularly concerned, I may just allude to Certain differences between the sexes which apparently depend on differences in their habits of life ; for such cases, though common in the lower, are rare in the higher classes. Two humming-birds belonging to the Senus Eustephanus, which inhabit the island ot .luan Fernandez, were long thought to be specifically distinct, but are now known, as Mr. Gould informs me, to be the ®eXes of the same species, and they differ slightly in the form of the beak. In another genus of humming-birds (Grypus), the beak of the male is serrated along the margin and hooked at the extremity, thus differing m,>ch from that of the female. In the curious Neomor- Pha of Hew Zealand, there is a still wider difference in lbe form of the beak ; and Mr. Gould has been informed fbat the male with his “ straight and stout beak tears the bark of trees, in order that the female may on the uncovered larvce with licr weaker and moie curved beak. Something of the same kind may be observed with our goldfinch (Cardueli s elerjans), tor I
2 Gould, < Handbook to the Birds of Australia,’ 1865, vol. ii. p. 383.
40 SEXUAL SELECTION : BIRDS. Part II.'
am assured by Mr. J. Jenner Weir that the bird- catchers can distinguish the males by their slightly longer beaks. The flocks of males, as an old and trust- worthy bird-catcher asserted, are commonly found feed- ing on the seeds of the teazle (Dipsacus) which they can reach with their elongated beaks, whilst the females more commonly feed on the seeds of the betony or Scrophularia. With a slight difference of this nature as a foundation, we can see how the beaks of the two sexes might be made to differ greatly through natural selection. In all these eases, however, especially in that of the quarrelsome humming-birds, it is possible that the differences in the beaks may have been first acquired by the males in relation to their battles, and afterwards led to slightly changed habits of life.
Law of Battle. — Almost all male birds are extremely pugnacious, using their beaks, wings, and legs for fighting together. We see this every spring with our robins and sparrows. The smallest of all birds, namely the hum- ming-bird, is one of the most quarrelsome. Mr. Gosse 3 describes a battle, in which a pair of humming-birds seized hold of each other’s beaks, and whirled round and round, till they almost fell to the ground ; and M. Montes de Oca, in speaking of another genus, says that two males rarely meet without a fierce aerial encounter : when kept in cages “ their fighting has mostly ended “ in the splitting of the tongue of one of the two, which “ then surely dies from being unable to feed.”4 With Waders, the males of the common water-hen ( Gallinula chlorojpus) “ 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 efieaeed
O O
3 Quoted by Mr. Gould, 1 Introduction to the Trochilidaj,’ 1861 p. 29
4 Gould, ibid. p. 52.
CiUp. XIII. ■
LAW OF BATTLE.
41
half an hour, until one got hold of the head of the °ther which would have been killed, had not the ob- s« ver interfered ; the female all the time looking on as a duiet spectator.5 The males of an allied bird ( Galli - wistutux), as Mr. Blyth informs me, are one third '^'ger than the females, and are so pugnacious during breeding-season, that they are kept by the natives ot Eastern Bengal for the sake of lighting. Various ler birds are kept in India for the same purpose, for ^stance the Bulbuls ( Pycnonotus hsemorrhous) which %ht with great spirit.” 6
1 be polygamous Ruff ( Machetes puynax, fig. 37) is glorious for his extreme pugnacity; and in the spring, ,, e 'nates, which are considerably larger than the morales, congregate day alter day at a particular spot, fhere the females propose to lay their eggs. The s°'vlers discover these spots by the turf being trampled 0>UQWhat bare. Here they fight very much like game- 0chs, seizing each other with their beaks and striking ll j their wings. The great ruff of feathers round the t(eck is then erected, and according to Ool. Montagu c ®Weeps the ground as a shield to defend the more euc*er parts;” and this is the only instance known
to shield
n*e iu the case of birds, of any structure serving as a
The ruff of feathers, however, from its varied 1 rich colours probably serves in chief part as an ^u«nent. Like most pugnacious birds, they seem kil'.ays ready to fight, and when closely confined often p ea)'h other; but Montagu observed that their luif!laCity becomes greater during the spring, when the at ^ , b-athers on their necks are fully developed; and ds period the least movement by any one bird
J • ^kompson, ‘Nat. Hist, of Ireland : Birds,’ 'aon. ‘ Birds of India,’ 1803, vol. ii. p. 90.
vol. ii. 1850, p. 327
42
SEXUAL SELECTION : BIEDS.
Part It
provokes a general battle.7 Of the pugnacity of web- footed birds, two instances will suffice : in Guiana “ bloody “fights occur during the breeding-season between the
7 Macgillivray, 1 Hist. Brit. Birds,’ vo). iv. 1852, p. 177-181.
LAW OF BATTLE.
43
t'n
XIII.
(( males of the wild musk-duck ( Cairina moscliata) ;
aud where these fights have occurred the river ‘‘ is covered for some distance with feathers.”8 Birds "hich seem ill-adapted for fighting engage in fierce conflicts ; thus with the pelican the stronger males j 1 'v° away the weaker ones, snapping with their '’'Re beaks and giving heavy blows with their wings. 5a]e snipes fight together, “tugging and pushing each ( other with their bills in the most curious manner lrnaginable.” Some few species are believed never to 1 pB t ; this is tlie case, according to Audubon, with one °| ,ll« woodpeckers of the United States {Ticus ciuratus), a though “ the hens are followed by even halt a dozen their gay suitors.” 9
Tl*e males of many birds are larger than the females, this no doubt is an advantage to them in their titles with their rivals, and has been gained through aexual selection. The difference in size between the "o sexes is carried to an extreme point in several Australian species ; thus the male musk-duck (Biziura) a!^ fl'e male Cincloramphus cruralis (allied to our j'd’jts) are by measurement actually twice as large as weir respective females.10 With many other birds the 6luales are larger tbau the males; aud as formerly Remarked, the explanation often given, namely that the crjutles have most of the work in feeding their young, 1 1 uot suffice. In some few cases, as we shall here- a^er see, the females apparently have acquired their Sweater size and strength for the sake of conquering er females and obtaining possession of the males.
Sehoinburgk, in ‘Journal of B. Geograph. Soc.’ vol. xiii.
sel * ^“hUological Biography,’ vol. i. p. 191. Bor pelicans and snipes, 1. !!}• lii- P- 381, 177.
Gould, ‘Handbook of Birds of Australia,’ vol. i. p. 395; vol. n. p. 383.
44
SEXUAL SELECTION : BIRDS.
Part II-
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 writer11 that in Derbyshire a kite struck at a game-hen accompanied by her chickens, w'hen the cock rushed to the rescue and drove his spur right through the eye and skull of the aggressor. The spur was with difficulty drawn from the skull, and as the kite though dead retained liis 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 following 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 upright, he would continue fighting. This was effected on the spot, and the bird fought with undaunted courage until he received his death- stroke. In Ceylon a closely-allied aud wild species, the Gallus Stanleyi, is known to fight desperately “ in “ defence of his seraglio,” so that one of the combatants is frequently found dead.12 An Indian partridge ( OritJ ■ gornis gularis), the male of which is furnished with strong and sharp spurs, is so quarrelsome, “that the “ scars of former fights disfigure the breast of almost “ every bird you kill.” 13
The males of almost all gallinaceous birds, even those which are not furnished with spurs, engage during the breeding-season in fierce conflicts. The Capercailzie and
11 Mr. Hewitt in the ‘ Poultry Book by Tegetmeier,’ 1866, p. 137.
12 Layard, ‘ Annals and Mag. of Nat. Ilist.’ vol. xiv. 1854, p. 63.
13 Jerdon, ‘ Birds of India,’ vol. iii. p. 574.
LAW OF BATTLE.
45
C'Up. XIII.
Black-,
Wll
rluriri
%ht
cock ( Tetrao urog alius and T. tetrix), which are polygamists, have regular appointed places, where g many weeks they congregate in numbers to - together and to display their charms before the ^‘Oales. ]\I. \V. Kowalevsky informs me that in Russia le bas seen the snow all bloody on the arenas where „ e Capercailzie have fought ; and the Black-cocks ^ ^ake the feathers fly in every direction,” when ovexal “engage in a battle royal.” The elder Brehm "es a curious account of the Balz, as the love-dance ry.1 ^ve-song of the Black-cock is called in Germany.
’.e bird utters almost continuously the most strange ls°'Ses : “ he holds his tail up and spreads it out like a « u"’ be lifts up his head and neck with all the feathers (! ?lect> and stretches his wings from the body. Then
takes a few jumps in different directions, some- in a circle, and presses the under part of his
“be “times “ b V
<( a c so hard against the ground that the chin-feathers « rnbhed off. During these movements he beats « 8 w'ngs and turns round and round. The more
(( c c ent he grows the more lively he becomes, until at 8 s ' the bird appears like a frantic creature.” At beCU timeS tlle black-cocks are so absorbed that they CaCortle almost blind and deaf, but less so than the tl I lcailzie; hence bird after bird may be shot on
After
the
Perf^1^6 Sl,0t’ or even caught by the hand, the °lrning these antics the males begin to fight : and Same black-cock, in order to pi-ove his strength over
feveral
antagonists, will visit in the course of one morn-
Sevei'al Balz-places, which remain the same during "««*»! years.1*
rois 1 Ulust. TMerletjen,’ 1807, D. iv. s. 851. Some of the foie- > 6meilts are taken from L. Lloyd, ‘ The Game Birds of U’ &c.. 1867, p. 79.
SEXUAL SELECTION : BIRDS.
Part It
46
The peacock with his long train appears more like 9 dandy than a warrior, but he sometimes engages i° fierce contests: the Rev. W. Darwin Fox informs ®c that two peacocks became so excited whilst fighting a* some little distance from Chester that they flew over the whole city, still fighting, until they alighted on tk® top of St. John's tower.
The spur, in those gallinaceous birds which are thus provided, is generally single; but Polyplectron (se® fig. 51 , p. 90) has two or more on each leg ; and one of the Blood-pheasants ( Ithaginis emeritus ) has been seel1 with five spurs. The spurs are generally confined to tk® male, being represented by mere knobs or rudiments 111 the female; but the females of the Java peacock (PaV° muticus ) and, as 1 am informed by Mr. Blvth, of the small fire-backed pheasant ( Euplocamus erythropthalmus) p«s' sess spurs. In G-alloperdix it is usual for the males t® have two spurs, and for the females to have only on® on each leg.18 Hence spurs may safely be considered as a masculine character, though occasionally transferred in a greater or less degree to the females. Like most other secondary sexual characters, the spurs are highly variable both in number and development in the sa®® species.
Various birds have spurs on their wings. But tk® Egyptian goose ( Chenalopex ssgyptiacus ) has only “ bai’6’ “ obtuse knobs,” and these probably shew us the firs steps by which true spurs have been developed in other allied birds. In the spur-winged goose, Pledropter $ gambensis, the males have much larger spurs than tk® females ; and they use them, as I am informed by Jl1’1 Bartlett, in fighting together, so that, in this case, tlF
15 Jerdon, * Birds of India on Ithaginis, vol. iii. p. 523 ; on Gall0' perdix, p. 541.
ClUf. XIII.
LAW OF BATTLE,
47
j'/'g-spurs serve as sexual weapons ; but according to Vlngstone, they are chiefly used in the defence of the • °Utlg- The Palamedea (fig. 88) is armed with a pair of
Palamedea cornuta (Irom Brehra), shewing the double- wing-spurs, and the filament on the head.
48
SEXUAL SELECTION : BIRDS.
Part j
spurs on eacli wing ; and these are such formidable we»' pons that a single blow has driven a dog howling away- But it does not appear that the spurs in this case, or i" that of some of the spur-winged rails, are larger in the male than in the female.10 In certain plovers, howeveL the wing-spurs must be considered as a sexual character- Thus in the male of our common peewit ( Vanellus crt? tatus ) the tubercle on the shoulder of the wing become® more prominent during the breeding-season, and the males arc known to fight together. In some speck5 of Lobivanellus a similar tubercle becomes develop®^ during the breeding-season “into a short horny spur. In the Australian L. lobatus both sexes have spurs, bid these are much larger in the males than in the female5. In an allied bird, the JToplopterus armatus. the spur5 do not increase in size during the breeding-season ; bid these birds have been seen in Egypt to fight together in the same manner as our peewits, by turning suddenly in the air and striking sideways at each other, some' times with a fatal result. Thus also they drive away’ other enemies.17
The season of love is that of battle ; but the male5 of some birds, as of the game-fowl and ruff, and eve11 the young males of the wild turkey and grouse,18 aff ready to fight whenever they meet. The presence the female is the teterrima belli causa. The Bengal1
16 for the Egyptian goose, see Mncgillivray, ‘British Birds,’ vol. ,v' p. 039. For Pleetropterus, ‘ Livingstone's Travels,’ p. 254. For l’idr raedea. B robin s ‘ Thierleben,’ B. iv. s. 740. See also on this bird Aw rll‘ - Voyages dans I’Amdrique merid.' tom. iv. 1809, p. 179, 253.
17 See, on our peewit, Mr. It. Carr in ‘ Land and Water,’ Aug. SyJ 1868, p. 46. In regard to Lobivanellus, see Jerdou’s ‘Birds of Indto vol. iii. p. 647, and Gould’s ‘Handbook of Birds of Australia,’ VolA1, p. 220. For the Ilolopterus, see Mr. Allen in the ‘ Ibis,’ vol. v. IS®3’ p. 156.
18 Audubon, ‘ Ornitli. Biography,’ vol. ii. p. 492 ; vol. i. p. 4-13.
LAW OF BATTLE.
49
C«AP.
'• XIII.
^abi
, 'Oos make the pretty little males of the amadavat Wstretda amandava ) fight together by placing three
small
cages in a row, with a female in the middle ;
a ter a little time the two males are turned loose, and
‘^mediately a desperate battle ensues.19 When many
lnales congregate at the same appointed spot and fight
|°gether, as in the case of grouse and various other
they are generally attended by the females,20
p afterwards pair with the victorious combatants.
mt in some cases the pairing precedes instead of suc-
ceeding the combat: thus, according to Audubon,21
8everal males of the Virginian goat-sucker ( Capri -
'^gus Virginianus) “ court, in a highly entertaining
„ ^aQner, the female, and no sooner has she made her
(l e than her approved gives chase to all intruders,
•md drives them beyond his dominions.” Generally
16 males try with all their power to drive away or kill
u 61r rivals before they pair. It does not, however,
appear that the females invariably prefer the victorious
lcl es. I jlavc indeed been assured by M. W. Kowa- revsk • - -
a^'sky that the female capercailzie sometimes steals th a young male who has not dared to enter
Q e ai’eQa with the older cocks ; in the same manner as ^Ccasionaiiy happens with the does of the red-deer in sii 1 (I* ^ hen two males contend in presence of a
^ e female, the victor, no doubt, commonly gains his
Mu Blyth, < Land mid Water,’ 1SG7, p. 212.
n ■ , ■ j leuiu huh vvaier, 10
p, 34010 lardson, on Tetmo umbelluB, ‘ Fauna Bor. Amcr. : Birds,’ 1831, Canp. ' .,L- Ll°yd, 1 Game Birds of Sweden,’ 1S07, p. 22, 79, on the - rcauzie and black-.
B
:-cock.
_ _ Breluri, however, asserts ‘Thierleben,’ &c.,
the p,S,' 352i that in Germany the 'grey-hens do not generally attend a °f the 'black-cocks, but this is an exception to the common is WP0SsibIy the hens may lie hidden in the surrounding bushes, _ as oth,„. J'Vn to bo the case with the grey-hens in Scandinavia, and with er sPecier -- ” •
13 in N. America.
-i . , , . ■ America.
’mthological Biography,’ vol. ii. p. 275. V°V II.
E
50 SEXUAL SELECTION : BIKDS. Part H-
desire ; but some of these battles are caused by wander- ing males trying to distract the peace of an already mated pair.22
Even with the most pugnacious species it is probable that the pairing does not depend exclusively on th® mere strength and courage of the male : for such males are generally decorated with various ornaments* which often become more brilliant during the breeding' season, and which are sedulously displayed before tl>(; females. The males also endeavour to charm or ex- cite 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 ar® invariably compelled to yield to the victorious malt'8. 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 Tdrao uW lettus, a good observer23 goes so far as to believe that the battles of the males “ are all a sham, performed “ to show themselves to the greatest advantage before “ the admiring females who assemble around ; for J “have never been able to find a maimed hero, aDu “ seldom more than a broken feather.” I shall hav® to recur to this subject, but I may here add that with the Tetrao cupido of the United States, about a score males assemble at a particular spot, and strutting abo®* make the whole air resound with their extraordinary noises. At the first answer from a female the mal®5 begin to fight furiously, and the weaker give way ; but then, according to Audubon, both the victors and van- quished search for the female, so that the females must
2i Brehm, ‘ Thierleben,’ &c., B. iv. 1867, p. 990. Audubon, ‘ Ornitt’* Biography,’ vol. ii. p. 492.
25 ‘ Land and Water,’ July 25tli, 1868, p. 14.
VOCAL MUSIC.
51
Cn«“. XIII,
Bitber then exert a choice, or the battle must be re- Jwed. So, again, with one of the Field-starlings of he United States ( Sturnella ludoviciana ) the males ftngage in fierce conflicts, “ but at the sight of a female 1 ley all fly after her, as if mad.” 24
^ 0e«Z and instrumental Music. — With birds the voice eiv°s to express various emotions, such as distress, fear, "U8eb triumph, or mere happiness, it is apparently Retimes used to excite terror, as with the hissing '°lse made by some nestling-birds. Audubon25 relates ^ at a night-heron ( Ardea nycticorax, Linn.) which he ' l’1 tame, used to hide itself when a cat approached, then “ suddenly start up uttering one of the most <( r%htful cries, apparently enjoying the cats alarm and flight.” The common domestic cock clucks to 6 hen, and the hen to her chickens, when a dainty <t0rsel is found. The hen, when she has laid an egg, „ 'aPeats the same note very often, and concludes with and SlXth ahove, which she holds for a longer time ; ”26 an' ^1U:s sh® expresses her joy. Some social birds ^Patently call to each other for aid ; and as they flit ai°Ul tfee to tree, the flock is kept together by chirp sWeriug chirp. During the nocturnal migrations of V'uf0 aiJ'* other water-fowl, sonorous clangs. from the i r ma.v be heard in the darkness overhead, answered 8- e angs in the rear. Certain cries serve as danger- s’ which, as the sportsman knows to his cost, are '!'h !lu^eTsto°d by the same species and by others. in f .rustic cock crows, and the humming-bird chirps, ilUrnph over a defeated rival. The true song, how-
P.I9^duWs ‘ Ornitliolog. Biography ; ’ on Tetrao cupido, vol. ii. 24 ‘o'*'1 ^'e ^turnus, vol. ii. p. 219.
26 rnahologioal Biograph.’ vol. v. p. 601.
e Hon. Daines Barrington, ‘ Philosoph. Transact.’ 1773, p. 252.
E 2
52
SEXUAL SELECTION : BIRDS.
Part H-
ever, 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 e-vd lived than Montagu, and he maintained that the “ male8 “ 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.”27 Mr. Jenner Weir informs me that this is certainly the case with the nightingale. Becb' stein, 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.”*4 There can be im doubt that birds closely attend to each other’s song. Mr. Weir has told me of the case ot a bullfinch which had been taught to pipe a GermaU waltz, and who was so good a performer that he cost ten guineas ; when this bird was first introduced into a room where other birds were kept and he began to sing, all the others, consisting of about twenty linnet8 and canaries, ranged themselves on the nearest side ot their cages, and listened with the greatest interest to the new performer. Many naturalists believe that the singing of birds is almost exclusively “ the effect of ri' “ valry and emulation,” and not for the sake of charmiufl their mates. This was the opinion of Dailies Barrington and \Y lute ot Selborne, who both especially attended to
37 1 Ornithological Dictionary,’ 1S33, p. 475.
28 ‘ Naturgeschichte der Stubenvdgel,’ 1840, s. 4. Mr. Harrison W®* likewise writes to me : — “ 1 am informed that the best singing male° “ generally get a mate first when they are bred in the same room.”
CflAP. XIII.
VOCAL MUSIC.
53
subject.29 Barrington, however, admits that “ supe- s< ri0I% in song gives to birds an amazing ascendancy °yer others, as is well known to bird-catchers.”
I is certain that there is an intense degree of rivalry etween the males in their singing. Bird-fanciers lUatf'b their birds to see which will sing longest ; and 'vas told by Mr. Yarrell that a first-rate bird will betimes sing till he drops down almost dead, or, Wording to Beclistein,30 quite dead from rupturing a vessel in the lungs. Whatever the cause may be, ?ale birds, as I hear from Mr. Weir, often die sud- ,6Qly during the season of song. That the habit of ^Bging is sometimes quite independent of love is clear,
as
a sterile hybrid canary-bird has been described3 singing whilst viewing itself in a mirror, and then f ling at its own image; it likewise attacked with 'iry a female canary when put into the same cage, jealousy excited by the act of singing is constantly advantage of by bird-catchers ; a male, in good 0ll& is hidden and protected, whilst a stuffed bird, sur- Gunded by limed twigs, is exposed to view. In this fanner a man, as Mr. Weir informs me, has caught, in course of a single day, fifty, and in one instance toVej%! male chaffinches. The power and inclination ,Slng differ so greatly with birds that although the ^ ee °f an ordinary male chaffinch is only sixpence, tin" ^ e*r 8aw oue bird for which the bird-catcher asked Pounds; the test of a really good singer being ro continue to sing whilst the cage is swung
ibe owner’s head.
lat birds should sing from emulation as well as for
tory 'fbiiosophical Transactions,’ 1773, p. 263. White’s • Natural His- 3o /^Ihorne,’ vol. i. 1825, p. 246. si >Tajurges. der Stubenvogel,’ 1S40, s. 252. r> Bol<b ‘ Zoologist,’ 1843-44, p. 659.
54
SEXUAL SELECTION : BIRDS.
Pari li-
the sake of charming the female, is not at all incom- patible ; and, indeed, might have been expected to g° together, like decoration and pugnacity. Some authors, however, argue that the song of the male cannot serve to charm the female, because the females of some feW species, such as the canary, robin, lark, and bullfinch, especially, as Bechstein remarks, when in a state of widowhood, pour forth fairly melodious strains. In some of these cases the habit of singing may be in part attributed to the females having been highly fed and confined,83 for this disturbs all the usual functions con- nected with the reproduction of the species. Many in- stances have already been given of the partial trans- ference of secondary masculine characters to the female, so that it is not at all surprising that the females of some species should possess the power of song. It has also been argued, that the song of the male cannot serve as a charm, because the males of certain species, for in' stance, of the robin, sing during the autumn.33 But nothing is more common than for animals to take plea- sure in practising whatever instinct they follow at other times for some real good. How often do we see bird3 which ily easily, gliding and sailing through the air obviously for pleasure. The cat plays with the cap- tured mouse, and the cormorant with the captured fish- The weaver-bird (Ploceus), when confined in a cage> amuses itself by neatly weaving blades of grass between the wires of its cage. Birds which habitually figb11 during the breeding-season are generally ready to figh* at all times ; and the males of the capercailzie som©' times hold their lalzens or leJcs at the usual place ()t
32 D. Barrington, 1 Phil. Transact.’ 1773, p. 262. Bechstein, ‘ S*0* benvogel,’ 1840, s. 4.
33 This is likewise the case with the water-ouzel, see Mr. Hepburn in the ‘Zoologist,’ 1845-1846, p. 1068.
VOCAL MUSIC.
55
Ca.
Xr. XIII.
assetnblage during the autumn.34 Hence it is not at all ^Prising that male birds should continue singing for 1<Jir own amusement after the season for courtship is
over.
Singing is to a certain extent, as shewn in a previous plaPter, an art, and is much improved by practice. >lrcis can be taught various tunes, and even the un- J?®l°dious sparrow has learnt to sing like a linnet.
ley acquire the song of their foster-parents, and betimes that of their neighbours.36 All the common °ngsters belong to the Order of Insessores, and their Y°cal organs are much more complex than those ot 'nost other birds ; yet it is a singular fact that some 0 the Insessores, such as ravens, crows, and magpies, the proper apparatus,37 though they never sing, not naturally modulate their voices to any great ^tent. Hunter asserts38 that with the true songsters he muscles of the larynx are stronger in the males . 01 in the females ; but with this slight exception there 110 difference in the vocal organs of the turn sexes, alt!‘OUgh t!ie maleg 0f most Species sing so much better atld more continuouslv than the females.
It '
Tl
a*d do
ae
is remarkable that only small birds properly sing. Australian genus Menura, however, must be ex- ^Pted ; for tdre Menura Alberti, which is about the size t( . a half-grown turkey, not only mocks other birds, but lts own whistle is exceedingly beautiful and varied.” Ie males congregate and form “ corroborying places,” lere they sing, raising and spreading their tails like
35 bloyd, ‘Game Birds of Sweden,’ 1867, p. 25.
3s r^nington, ibid. p. 264. Beobstein, ibid. s. 5.
3, , do la Malle gives a curious instance (‘ Annales des Sc. Nat.
iu perles’ ZlJolog. tom. x. p. 118) of some wild blackbirds in his garden
37 a*s wtieh naturally learnt from a caged bird a republican ail.
38 ®isllop, in * Todd s' Cyclop, of Anat. and Phys.’ vol. iv. P- H96. ■'ts stated by Barrington in ‘Philosoph. Transact.’ 1773, p. 2b2.
56
SEXUAL SELECTION: BIRDS.
Part 0>
peacocks and drooping their wings.39 It is also re- markable that the birds which sing are rarely decorated with brilliant colours or other ornaments. Of our British birds, excepting the bullfinch and goldfinch, the best songsters are plain-coloured. The king-fisher, bee-eater, roller, hoopee, woodpeckers, &c., utter harsh cries ; and the brilliant birds of the tropics are hardly ever song' sters.40 Hence bright colours and the power of song seem to replace each other. We can perceive that if the plumage did not vary in brightness, or if bright colours were dangerous to the species, other means would have to be employed to charm the females; and the voice being rendered melodious would offer one such means.
In some birds the vocal organs differ greatly in the two sexes. In the Tetrao citpido (fig. 39) the male has two bare, orange-coloured sacks, one on each side of the neck ; and these arc largely inflated when the male, during the breeding-season, makes a curious hollow sound, audible at a great distance. Audubon proved that the sound was intimately connected with this ap' paratus, which reminds us of the air-sacks on each side of the mouth of certain male frogs, for he found that the sound was much diminished when one of the sack* of a tame bird was pricked, and when both were pricked it was altogether stopped. The female has “a some* “ what similar, though smaller, naked space of skin ou “ the neck; but this is not capable of inflation.”41 The
39 Gould, ‘ Handbook to tlio Birds of Australia,’ vol. i. 1865, p. 60S' 310. See also Mr. T. W. Wood in the 1 Student,’ April, 1870, p. 125.
40 See remarks to this effect in Gould’s ‘ Introduction to the Trochi' lid*,’ 1861, p. 22.
41 ' The Sportsman and Naturalist in Canada,’ by Major W. Ross King, 1866, p. 114-116. Mr. T. W. Wood gives in the ‘Student (April, 1870, p. 116) an excellent account of the attitude and habits o* this bird during its courtship. He states that the ear-tufts or neck' plumes are erected, so that they meet over the crown of the head.
XIII.
VOCAL MUSIC.
57
Ch
j\e °f another kind of grouse (Tetrao urophasianus), it !"st courting the female, has his “ bare yellow oeso- n laSUs inflated to a prodigious size, fully half as large as file body;” and he then utters various grating,
Fig. 39. Tetrao cupido : male. (From Brehm.)
58
SEXUAL SELECTION : BIRDS.
Part It
deep liollow tones. With his neck-feathers erect, hi3 wings lowered and buzzing on the ground, and his long pointed tail spread out like a fan, he displays a variety of grotesque attitudes. The oesophagus of the female is not in any way remarkable.42
It seems now well made out that the great throat- pouch of the European male bustard (Otis tarda), and of at least four other species, does not serve, as w»s formerly supposed, to hold water, hut is connected with the utterance during the breeding-season of a peeuhar sound resembling “oek.” The bird whilst uttering tin9 sound throws himself into the most extraordinary atti- tudes. It is a singular fact that with the males of tbe same species the sack is not developed in all the indi- viduals.43 A crow-like bird inhabiting South A meric0,
( Oephahpterus ornatus, fig. 40) is called the umbrella bird, from its immense top-knot, formed of bare white quills surmounted by dark-blue plumes, which it ca® j elevate into a great dome no less than five inches i® / diameter, covering the whole head. This bird has 0® its neck a long, thin, cylindrical, fleshy appendage, which ; is thickly clothed with scale-like blue feathers. It pro- bably serves in part as an ornament, but likewise as 9 resounding apparatus, for Mr. Bates found that it 19 connected “ with an unusual development of the tracin'9 ■ “ and vocal organs.” It is dilated when the bird utter3 its singularly deep, loud, and long-sustained fluty not®*
/
42 Richardson, ‘Fauna Bor. Americana: Birds,’ 1831, p. 359. A'r dubon, ibid. yol. iv. p. 507.
43 The following papers have been lately written on this subject Prof. A. Newton, in the ‘Ibis,’ 1S62, p. 107; Dr. Cullen, ibid. I8*p' p. 145 ; Mr. Flower, in ‘ Proc. Zool. Soc.’ 1865, p. 747 ; and Dr. Muricj in ‘Proc. Zool. Soc.’ 1868, p. 471. In tbis latter paper an exoelleI) figure is given of the male Australian Bustard in full display with tke sack distended.
\ v_ln . j mm: i im \ ns
VOCAL MUSIC.
59
c«.
Ap- XIII.
} 'le head-crest and neck-appendage are rudimentary 11 the female.44
ly Alie vocal organs of various web-footed and wading ( ' 1 ' lS ai'e extraordinarily complex, and differ to a certain X'('I1t in tlie two sexes. In some cases the trachea is
40- The Umbrella- Bird or Ceplmlopterus omatns (male, from Brclmi;
a French horn, and is deeply embedded I<; sternum. In the wild swan (Cygnus ferns') it is
Naturalist on the Amazons,’ 1S63, vol. ii, p. 284 ; larger r,’ m l-*3ro°- Zool. Soe.’ 1850, p. 206. A new species, witli a still ‘Ibis > “e.ok'aPPendage (C. penduliger), has lately been discovered, see ’ °‘- 1- p. 457.
60 sexual selection: birds. part11,
more deeply embedded in the adult male than in th® female or young male. In the male Merganser tb® enlarged portion of the trachea is furnished with 0® additional pair of muscles.45 But the meaning of thew differences between the sexes of many Anatidse is n(lt at all understood ; for the male is not always the mol® vociferous ; thus with the common duck, the male hissed whilst the female utters a loud quack.46 In both sexes 0* one of the cranes (Grus virgo ) the trachea penetrate8 the sternum, but presents “ certain sexual modifications- In the male of the black stork there is also a well' marked sexual difference in the length and curvature of the bronchi.47 So that highly important structures ha*® in these cases been modified according to sex.
It is often difficult to conjecture whether the man) strange cries and notes, uttered by male birds during the breeding-season, serve as a charm or merely as 11 call to the female. The soft cooing of the turtle-do*® and of many pigeons, it may be presumed, pleases th® female. "When the female of the wild turkey utters hfc’r call in the morning, the male answers by a differed note from the gobbling noise which he makes, whe’1 with erected feathers, rustling wings and distended wattles, he puffs and struts before her.48 The spel °* the black-cock certainly serves as a call to the female for it has been known to bring four or five female5
45 Bishop, in Todd’s ‘ Cyclop, of Anat. &n<l Phys.’ voL iv. p. 1409*
46 eia; spoonbill (Pinto Ji -a) has its trachea convoluted into a flgaf6 of eight, and yet this bird (Jordon, ‘ Birds of India,’ vol. iii. p. 768) >' mute ; hut Mr. Blyt.li informs me that the convolutions are not co"' stantly present, so that perhaps they are now tending towards aborti®4*'
4' ‘Elements of Coni]). Anat.’ by B, Wagner, Eng. translat. IS45, P’ 111. With respect to the swan, as given above, Yarrell’s ‘Hist. ot British Birds,’ 2nd edit. 1815, vol. iii. p, 193.
48 C. L. Bonaparte, quoted in the ‘ Naturalist Library : Birds,’ v®1, xiv. p. 126.
INSTRUMENTAL MUSIC.
61
CtUp,
XIII.
from
tlm if ^'s^ance to a male under confinement; but as - tack-cock continues bis spel for hours during ossivg days, and in the case of the capercailzie
‘‘with
that aU nbr°n^ °f Passi°n»” we are led to suppose cfi.1 . ^le telQades which are already present are thus auned« The voice of the common rook is known d ter during the breeding-season, and is therefore in
some
harsh
haix.1* "a^ sexual.50 But what shall we say about the
frav6 Screams °fr for instance, some kinds of macaws ; tlie? t^'ese birds as bad taste for musical sounds as ha," aPl)ai’cntly have for colour, judging by the in- genious contrai
phi ”'/uo ooonast of their bright yellow and blue 0f la§e • It is indeed possible that the loud voices ady ail'Y ma*° birds may be the result, without any flleautaSe being thus gained, of the inherited effects of exc.;'0«tinued use of their vocal organs, when they are rao.e.e. the strong passions of love, jealousy, and
cun. f to this point we shall recur when we treat of 4Ua<irupeds.
mai'j ^ave as yet spoken only of the voice, but the 'vhafS Vari°us birds practise, during their courtship,
Peacocks
music.
amf fr° C(dled instrumental
Ucfr of Paradise rattle their quills together, Vibratory movement apparently serves merely
atld the
to
of
) v-., i J »UW»UUiUIIU OVA U.O AAAVy L vlj
f tj? a n°ise, for it can hardly add to the beauty again?(-11'tfrJUmaoe‘ Turkey-cocks scrape their wings
Prod:
ground, and some kinds of grouse thus
®l'°Use ° a ^llzz'u£ sound. Another North American his j.. ’ ^ Tttrav umbelhis, when with his tail erect, “ , 8 displayed, “ he shows oif his finery to the
by es> who lie hid in the neighbourhood,” drums piuly striking his wings together above his
49 L T —
50 4 ^ame Birds of Sweden,’ &c., 1SG7, p. 22, 81. er> k Pliilosoph. Transactions,’ 1824, p. 20.
62
SEXUAL SELECTION: BIRDS.
Part
back, according to Mr. R. Haymond, and not, ,u Audubon thought, by striking them against his sideS' The sound thus produced is compared by some t£ distant thunder, and by others to the quick roll of 11 drum. The female never drums, “ but flies directly t0 “ the place where the male is thus engaged.” In tb® Himalayas the male of the Kalij-pheasant “ often mak®8 “ a singular dramming noise with his wings, not unlik® “ the sound produced by shaking a stiff piece of cloth- On the west coast of Africa the little black-weavef* (Ploceus?) congregate in a small party on the bushl>- round a small open space, and sing and glide through the air with quivering wings, “ which make a rap1'1 “ whirring sound like a child’s rattle.” One bird al't<?l another thus performs for hours together, but only duriPr the courting-season. At this same season the males ot certain night-jars (Caprimulgus) make a most strung® noise with their wings. The various species of wood peckers strike a sonorous branch with their beaks, wit 1 so rapid a vibratory movement that “the head appea1*’ “ to be in two places at once.” The sound thus pr° duced is audible at a considerable distance, but can not be described; and I feel sure that its cause wotu( never be conjectured by any one who heard it for tb' first time. As this jarring sound is made chiefly duttDe the breeding-season, it has been considered as a loV® song; but it is perhaps more strictly a love-call. lb® female, when driven from her nest, has been observe thus to call her mate, who answered in the sa#1® manner and soon appeared. Lastly the male Hoop0® (Upupa epops) combines vocal and instrumental musk > for during the breeding-season this bird, as Mr. Swinh°® saw, first draw's in air and then taps the end of beak perpendicularly down against a stone or the truf* v of a tree, “ when the breath being forced down tb®
INSTRUMENTAL MUSIC.
63
C«AP. XIII.
u "ilar Lill produces tlie correct sound.” When the . e utters its cry without striking his beak the sound Sjuite different.51
of 11 f°reg°ing cases sounds are made by the aid ^ sfouctures already present and otherwise necessary ; g ,ln the following cases certain feathers have been - ecially modified for the express purpose of producing
tj|e Souuds. The drumming, or bleating, or neignmg, or wl'U:;fonng noise, as expressed by different observers, ^ le 1 is made by the common snipe (Scolojpax gallinago) pjlSt ^Jave surprised every one who has ever lieai’d it. <i / ^ird, during the pairing-season, flies to “perhaps a for L°U*aEc! foot in height,” and after zig-zagging about an/ tlnie <fost'eil(ls in a curved line, with outspread tail fiuivering pinions, with surprising velocity to the
‘‘‘g. 41.
Outer tail-feather of ScoJopax gallinago (from Proc, Zoo). Soc. 1 853).
earth.
,j(. ' fhe sound is emitted only during this rapid
Jj ... t- No one was able to explain the cause, until fe^„ e?es observed that on each side of the tail the outer sab blS aie Peculiarly formed (fig. 41), having a stiff te'sliaped shaft, with the oblique barbs of unusual
Ji
L^ierlliZ? forgoing several facts see, on Birds of Paradise, Brchm, hor. ,6jen> Band iii. s, 325. On Grouse, ltichardson, ‘Fauna : Birds,’ p. 313 and 309; Major W. Ross Kin"-, ‘The ‘Qeol, f ln Canada,' 1866, p. 156; Mr. Haymoud, in Prof. Cox’s tl io^nra, \ "rvey °t' Indiana,’ p. 227; Auduhon, ‘American Ornitholog. fodia,,’ y' ,1 '• P- 216. On the Kalij-pheasant, Jerdon, 1 Birds of
"‘a- g’ l11' P- '’33. On the Weavers, ‘ Liviugslono’s Expedition to foitish ^865, p.425. On Woodpeckers, Macgillivray, ‘Hist, of ®*r. Swinh1*18’' Vo1' iii- 1810> T- 8‘b 88> 8lt IIU,1 95. On the Hoopoe, ^UbonV in ‘ Proc- Zoolog. Soc.’ June 23, 1S63. On the Night- Jar. ‘a the s lbi<1- v°k it- p. 255. The English Night-Jar likewise makes lllo a curious noise during its rapid flight.
64
SEXUAL SELECTION : BIRDS.
Pakt
Fig. 42. Outer tail-feather of Scolopax frenata. Fig. 13. Outer tail-feather of Scolopax javensis.
length, the outer webs being strongly bound together' He found that by blowing on these feathers, or by fasten' ing them to a long thin stick and waving them rapidly through the air, he could exactly reproduce the drum' ming noise made by the living bird. Both sexes »rfl furnished with these feathers, but they are generally
larger in the male than in the female, and ein't a deeper note. In soWe species, as in S.frend <* (fig. 42), four feather®) and in /S', javensis (h$* 43), no less than eigl’J on each side of the tan are greatly modified. Different tones are emitted l1) the feathers of the different species when waved throng'1 the air; and the Scolopax Wilsonii of the United Staff5 makes a switching noise whilst descending rapidly 1° the earth.52
In the male of the Chamrepctes unicolor (a large gall*' naceous bird of America) the first primary wing- feather is arched towards the tip and is much more attenuated than in the female. In an allied bird, the Peneloff nigra, Mr. Salvin observed a male, which, whilst ’ flew downwards “ with outstretched wings, gave fot^ “ a kind of crashing, rushing noise,” like the falli11' of a tree.62 The male alone of one of the Indim1 bustards ( Sypkeotides auritus ) has its primary win? feathers greatly acuminated; and the male of an alHe‘
52 Sec M. Meves- luteresting paper in ‘Proc. Zool. Soc.’ 1858, p. U) For the habits of the snipe, Maegillivray, ‘Ilist. British Birds,’ vol- ’ ' p. 371. For the American snipe, Capt. Blakiston, ‘Ibis,’ vol. v. '
p. 181. ...
33 Mr. Salvin, in ‘ Proc. Zool. Soe.’ 1867, p. 160. I am much 1 debted to this distinguished ornithologist for sketches of tho feather3 the Chamrepctes, and for other information.
INSTRUMENTAL MUSIC.
65
G«.
Ap- XIII.
e°ies ig known to make a humming noise whilst bin]1'11” ^le ^ema^e-54 In a widely different group of j. s’ Namely the Humming-birds, the males alone y Certain kinds have either M..° s^afts of their primary Of*1? '^eathers broadly dilated, re webs abruptly excised Waida f'10 extremity. The
fits 6’ l<>r llls1ail°e, of Selaspho- h * **"'
8 &atycereus, when adult, feat]^10 ^lst Primary wing-
as
thi aer (fig. 44), excised in fanner. Whilst flying
aial- ,^ower to flower ho did'68 " a s^n 'fi’ almost whistling,
Fig. 44. Primary wing-feather of a Humming-bird, the Kelasphvrus pla- iner us (from a sketch by Mr. Salvin). Upper figure, that of male; lower figure, corresponding feather of fe- male.
noise
;”65 hut it
t; 11011 appear to Mr. Salvin that the noise was iuten-
1 dade.
in several species of a sub-genus of Pipra or ^akin, the males have their secondary wing-feathers rein as descrihed by Mr. Sclater, in a still more deli a.r^a^e manner. In the brilliantly-coloured P.
e*osa the first three secondaries are thick-stemmed (fil CUlVe(i towards the body ; in the fourth and fifth auT a) the change is greater ; and in the sixth “ e Seveu,h (b. c) the shaft “ is thickened to an ^ho Ja°rdinary degree, forming a solid horny lump.” Paris ar^8 a^so are greatly changed in shape, in eom- 011 with the corresponding feathers (d, e,f) in the
Even the hones of the wing which support.
tl)£§£
Slngular feathers in the male are said by Mr. Ser to be much thickened. These little birds make
*4 j
55 Qo(n ' Birds of India>’ vo1- iU- P- 618, 621 ■ 'Hoc 7 * Introduction to the Trocliilidoe,’ i
V0L “l0S- *».' 1807, p. 100.
1801, p. 49- Salvin,
66
SEXUAL SELECTION. BIKDS.
Part It
an extraordinary noise, the first “ sharp note being not “ unlike the crack of a whip.” 66
d e f
Fig. 45. Secondary wing-feathers of Pipra deliciosa (from Mr. Sclater, in Proc. Zool. 1860). The three upper feathers, a, b, c, from the male ; the three lower corresponding feathers, d, e,f, from the female.
a. and d. Fifth secondary wing-feather of male and female, upper surface. b and Sixth secondary, upper surface. c and/. Seventh secondary, lower surface.
The diversity of the sounds, both vocal and instru- mental, made by the males of many species during the
55 Sclater, in ‘Proc. Zool. Soc.’ 1860, p. 90, and in ‘Ibis,’ vol. iv’ 1862, p. 175. Also Salvin, in ‘ Ibis/ 1860, p. 37.
C«AP. XIII.
VOCAL AND INSTRUMENTAL MUSIC.
67
reeding-Seas01i, and the diversity of the means for th , ^ SU(‘h sounds, are highly remarkable. We 115 gain a high idea of their importance for sexual P°ses, and are reminded of the same conclusion with ]. ' Pe°t to insects. It is not difficult to imagine the steps -Mch the notes of a bird, primarily used as a mere 1 or for some other purpose, might have been im- 'ed into a melodious love-song. This is somewhat °!e difficult in the case of the modified feathers, by *he drumming, whistling, or roaring noises are th*/ Uce^‘ But we have seen that some birds during ' °ourtship flutter, shake, or rattle their unmodified
lathers together ; and if the females were led to select 8tr _ est performers, the males which possessed the
the
at or thickest, or most attenuated feathers, situ- s ( 0n any part of the body, would be the most he 6SS^d i and thus by slow degrees the feathers might Modified to almost any extent. The females, of in |Se’ Wou^d not notice each slight successive alteration cu •• :d,e> hut only the sounds thus produced. It is a so i-'w dhat in the same class of animals, sounds erent as the drumming of the snipe’s tail, the
lilnf'11*’ °* ^le woodpecker’s beak, the harsh trumpet dov
^ I j ^ I
C1y ol certain water-fowl, the cooing of the turtle-
j ,|Cj. ’. and the song of the nightingale, should all be we dSing to the females of the several species. But ***** not judge the tastes of distinct species by a °f °r* standard ; nor must we judge by the standard "hat ,r ^as^e' Even with man, we should remember the i ^Sc°rdant noises, the beating of tom-toms and S;r g ri i notes of reeds, please the ears of savages. <( duiker remarks,67 that “ as the stomach of the prefers the raw meat and reeking liver taken
The Nile Tributaries of Abyssinia,’ 18G7, p. 203.
68
SEXUAL SELECTION : BIRDS.
Part O'
“ hot from the animal, so does his ear prefer his equally “ coai’se and discordant music to all other.”
Love-Antics and Lances. — The curious love-gestures of various birds, especially of the Gallinacem, have already been incidentally noticed ; so that little need here be added. In Northern America, large numbers of a grouse, the Tetrao phasianellus, meet every morning during the breeding-season on a selected level spot, and here they run round and round in a circle of about fifteen or twenty feet in diameter, so that the ground is worn quite bare, like a fairy-ring. In these Par- tridge-dances, as they are called by the hunters, the birds assume the strangest attitudes, and run round, some to the left and some to the right, Audubon describes the males of a heron (Ardea herodias ) as walking about on their long legs with great dignity before the females, bidding defiance to their rivals. With one of the disgusting carrion- vultures ( CatharteS jota) the same naturalist states that “the gesticulations and parade of the males at the beginning- of the “love-season are extremely ludicrous.” Certain birds perform their love-antics on the wing, as we have seen with the black African weaver, instead of on the ground. During the spring our little white-throat ( Sylvia cinerea) often rises a few feet or yards in the air above some bush, and “flutters with a fitful and 1 fantastic motion, singing all the while, and then drop8 ‘ to its perch. The great English bustard throws himself into indescribably odd attitudes whilst courting the female, as has been figured by Wolf. An allied Indian bustard (Otis bengalensis) at such times “rises “ perpendicularly into the air with a hurried flapping ot his wings, laising his crest and puffing out the “ feathers of his neck and breast, and then drops to the
Cu.
Ap- XIII.
LOVE-ANTICS.
69
‘ CY
s ° 0Tln(3 ; ” lie repeats this manoeuvre several times ton eSSIVely> at the same time humming in a peculiar “ s.l females as happen to he near “ obey this
tr atory summons,” and when they approach lie 4V“S W]nSs aud spreads his tail like a turkey-
e tlie most curious case is afforded by three allied
, Cla °f Australian birds, the famous Bower-birds,
^^loubt the co-descendants of some ancient species acquired the strange instinct of constructing
first
°°Wers
for performing their love-antics. The bowers
46),
r 'i'01 afett with feathers, “mlt (
f°r tlr
hich, as we shall hereafter see, are highly shells, bones and leaves, are °a the ground for the sole purpose of courtship, in tl eir 1K:'S*H are formed in trees. Both sexes assist civj. l'6 erection of the bowers, but the male is the prin- Workman. So strong is this instinct that it is
Strange has
noised under
described 69 the
confinement, and Mr me habits of some Satin Bower -birds, “ de kept in his aviary in New South Wales. “At
a .es die male will chase the female all over the or ^iGn 8° t0 die bower, pick up a gay feather
^1' large leaf, utter a curious kind of note, set all so ea~*eis erect, run round the bower and become k;s eXcited that his eyes appear ready to start from th . lCa< ’ he continues opening first one wing, and 11 die other, uttering a low, whistling note, and,
For
elrno phasianollus, see Richardson, ‘Fauna Bor. America,’
Ibis,’ 18G3, p. 125. Biography,’ vol. ii.
361 nn.1 r 1 ‘ 11 iJ 1 c-v. j ... , iau
* 0r tbe ;fr farther particulars Capt. Blalciston, ‘ t- atifia , am' Ardoa, Audubon, ‘Oruitk. uiugrapuy, vui.
Uj . }°r P- 89. On the White-throat, Macgillivray, ‘Hist. °f India ’ ' ,8’ V°F ii- p. 354. On the Indian Bustard, Jerdon, ‘ Birds
59 Boul f iiL P- 618.
f he bower' .^an(ibook to the Birds of Australia,’ vol. i. p. 444, 449, 455. bgicai Q,r°* *be Satin Bower-bird may always be seen in the Zoolo- ’ Miety’s Gardens, Regent’s Park.
70 SEXUAL SELECTION: BINDS. PARI &
“ like the domestic cock, seems to be picking up some- “ thing from the ground, until at last the female goes “ gently towards him.” Captain Stokes has described the habits and “play-houses” of another species, the
4P. XIII.
DECORATION.
71
G
X Sower-bird, which was seen “amusing itself by <( ayiug backwards and forwards, taking a shell alter- tl nately from each side, and carrying it through the f ar°kvvay iu its mouth.” These curious structures, a°rnied solely as halls of assemblages, where both sexes l^1’180 themselves and pay their court, must cost the fa s 111 uch labour. The bower, for instance, of the ehJ)n'bleasted sPecies> is nearly four feet in length, e teen inches in height, and is raised on a thick l atform of sticks.
decoration,'— 1 will first discuss the cases in which the ,es ai’e ornamented either exclusively or in a much ^8 ier degree than the females ; and in a succeeding ^aPter those in which both sexes are equally orna- 8oented, ami finally the rare cases in which the female is the 6W^at more rightly-coloured than the male. As with So ai dificial ornaments used by savage and civilised men, ^1G natural ornaments of birds, the head is the at t) Sea^ <d decoration.60 The ornaments, as mentioned div le.Commencement of this chapter, are wonderfully lle^.1'8'ded. The plumes on the front or back of the Ca c°nsist of variously-shaped feathers, sometimes >Ul erection or expansion, by which their beauti-
fy,. Cr^°Urs are fully displayed. Elegant ear-tufts (see som , ante) are occasionally present. The head is hll(U tilVJes covercd with velvety down like that of the fl asa»t ; or is naked and vividly coloured ; or supports d’he ^kl’cndages, filaments, and solid protuberances, .oat, also, is sometimes ornamented with a beard,
or
geriej1^1 Watt^es or caruncles. Such appendages are
61 ally brightly coloured, and no doubt serv
as
See
imal, to this effect, on the “Feeling of Beauty among
s’ by Mr. J. Shaw, in the 1 A
‘ Athenmum,’ Nov. 24th, 1866, p. 681.
72
sexual selection: birds.
Part H
ornaments, though not always ornamental in our eyes for whilst the male is in the act of courting the female they often swell and assume more vivid tints, as in the case of the male turkey. At such times the fleshy ap" pendages about the head of the male Trugopan phea* sant ( Ceriornis temminchii) swell into a large lapp®1 on the throat and into two horns, one on each side of the splendid top-knot ; and these are then coloured of the most intense blue which I have ever beheld. The African hornbill ( Bucorax abyssinicus ) inflates the scarlet bladder-like wattle on its neck, and with its wings drooping and tail expanded « makes quite a grand “ appearance. 61 Even the iris of the eye is sometime^ more brightly coloured in the male than in the female? and this is frequently the case with the beak, &r instance, in our common black-bird. In Buceros cor rugatus, the whole beak and immense casque at® coloured more conspicuously in the male than in the female; and “the oblique grooves upon the sides of “ the lower mandible are peculiar to the male sex.” 63 The males .are often ornamented with elongated fen' tliers or plumes springing from almost every part of th® body. The feathers on the throat and breast are some‘ times developed iuto beautiful rail's and collars. The tail-feathers are frequently increased in length ; as see in the tail-coverts of the peacock, and in the tail of the Argus pheasant. The body of this latter bird is larger than that ot a fowl ; yet the length from the end of the beak to the extremity of the tail is no less than five feet three inches.63 The wing-feathers are n°l elongated nearly so often as the tail-feathers ; for the'1
151 Mr. Monteiro, ‘ Ibis,’ vol. iv. 1862, p. 339.
62 1 Land and Water,* 1868, p, 217.
63 Jardine’s 1 Naturalist Library : Birds,’ vol. xiv. p. 166.
DECORATION.
Ch.
At>.
XIII.
I 6
w°uld impede the act of flight. Yet the ^tfuUy ocellated secondary wing-feathers of the ^ Argus pheasant are nearly three feet in length; n'C 111 a small African night-jar ( Cosmetornis vexilla- bi^'^i-0116 ^ie primary wing-feathers, during the Reason, attains a length of twenty-six inches, jn’ st Hie bird itself is only ten inches in length. of ^°tiier closely-allied genus of night-jars, the shafts tl|6 0 ^Dgated wing-feathers are naked, except at
^ot-remity, where there is a disc.14
Again, in
still * Senus of nightjars, the tail-feathers are even
Hill] °
^ lrj°re prodigiously developed ; so that we see the 111 kind of ornament gained by the males of closely-
birds'
f«ath
It
to
fhe in
Is, through the development of widely different
'erg.
18 a curious fact that the feathers of birds belonging
groups have been modified in almost exactly Same peculiar manner. Thus the wing-feathers
°Ue of r[U; above-mentioned night-jars are bare tl1(? & tUe shaft and terminate in a disc; or are, as J J are sometimes called, spoon or racket-shaped.
lers of this kind occur in the tail of a rnotmot ^ota swper ciliar is), of a king-fisher, finch, burn- ed PiUTot> several Indian drongos ( Dicrurus
anfl • °^MS> in one of which the disc stands vertically), UttJ11 ^'e ta^ certain Birds of Paradise. In these olT|,01 kirds, similar feathers, beautifully ocellated, ga]|U‘"‘ut the head, as is likewise the case with some aW).0la,'<!ons birds. In an Indian bustard ( Sypheotides ab0( Us) ^le feathers forming the ear-tufts, which are 1 i°ur inches in length, also terminate in discs.03
tio>i to ti teir’ in tlle ‘ tbis,’ vol. vi. 1864, p. 114. Livingstone, ‘ Expedi- 65 Jev.in Zaml,e“V 1865, p. 66.
n’ ‘Birds of India,’ vol. iii. p. 620.
74
SEXUAL SELECTION: BIRDS.
PABi1
The barbs of the feathers in various widely-disti°c birds are filamentous or plumose, as with some HeroO-' Ibises, Birds of Paradise and Gallinaceae. In othe| eases the barbs disappear, leaving the shafts bare; °’11 these in the tail of tho Paradhea apoda attain a lengt'1 of thirty-four inches.66 Smaller feathers when thfl denuded appear like bristles, as on the breast of turkey-cock. As any fleeting fashion in dress con11’’ to be admired by man, so with birds a change 0 almost any kind in the structure or colouring of t'1<J feathers in the male appears to have been admired W the female. The fact of the feathers in widely tinet groups, having been modified in an analog011’ manner, no doubt depends primarily on all the feath01" having nearly the same structure and manner of deV^ lopment, and consequently tending to vary in the manner. We often see a tendency to analogous vari9' bility in the plumage of our domestic breeds belong!0' to distinct species. Thus top-knots have appeared ,jl several species. In an extinct variety of the turk°)’ the top-knot consisted of bare quills surmounted wi^ plumes of down, so that they resembled, to a certa'1' extent, the racket-shaped feathers above described. I11 certain breeds of the pigeon and fowl the feathers il1'1 plumose, with some tendency in the shafts to be nak°^’ In the Sebastopol goose the scapular feathers are great!.' elongated, curled, or even spirally twisted, with margins plumose.67
In regard to colour hardly anything need here said ; lor every one knows how splendid are the th'*5
66 Wallace, in ‘Annals and Mag. of Nat. Hist.’ vol. xx. 1857, p. ilb and in his 1 Malay Archipelago,’ vol. ii. 1869, p. 390.
67 See ray work on * The Variation of Animals and Plants nndet Domestication’ vol. i. p. 289, 293.
DECORATION,
75
1-HlP
Xlii.
and how harmoniously they are combined. s colours are often metallic and iridescent. Circular ai'e sometimes surrounded by one or more differ- ut‘y shaded /ones, and are thus converted into ocelli.
Paradises rubra, male (from Brehm)
76 SEXUAL SELECTION: BIRDS. PAR? ^
Nor need much be said on the wonderful different between the sexes, or of the extreme beauty of ^ males of many birds. The common peacock offers 11 striking instance. Female Birds of Paradise &
Pig. 48.
Lophornis oniatus, male and female (from Brehm).
DECORATION,
xm.
77
ob.
tU,
rCUl'e]y coloured and destitute of all ornaments, whilst ^ales are pV0bably the most highly decorated of and in so many ways, that they must be
gjj »
Seeut8 ’ anc^ *n s0 many ways> f^at tliey
1 to be appreciated. The elongated and golden
Spilth uva underwoodi, male and female (from Brelim).
78
sexual selection: bieds.
Part
orange plumes which spring from beneath the 'v'n' of the Paradisea apoda (see fig. 47 of P. rubra, a less beautiful species), when vertically erected and to vibrate, are described as forming a sort of hal°' the centre of which the head “ looks like a h1,,,. “ emerald sun with its rays formed by the two plume* In another most beautiful species the head is “ and of a rich cobalt blue, crossed by several lines v “ black velvety leathers.” 69
Male humming-birds (figs. 48 and 49) almost with Birds of Paradise in their beauty, as every one admit who has seen Mr. Gould’s splendid volumes or rich collection. It is very remarkable in how nn11’, different ways these birds are ornamented. Almost part of the plumage has been taken advantage of & , modified; and the modifications have been carried. \ Mr. Gould shewed me, to a wonderful extreme in s0"' species belonging to nearly every sub-group. Such are curiously like those which we see in our fatw breeds, reared by man for the sake of ornament : cert*’ individuals originally varied in one character, and oh1 individuals belonging to the same species in 1 , characters ; and these have been seized on by man ^ augmented to an extreme point — as the tail of * j fantail-pigeon, the hood of the jacobin, the beak 0|1, wattle of the carrier, and so forth. The sole differ11 ( between these cases is that in the one the result is 1 1 , to man’s selection, whilst in the other, as with H11 j ming-birds, Birds of Paradise, &c., it is due to seZ'f, selection, — that is to the selection by the females of * more beautiful males.
. .{ft
68 Quoted from M. do Lafresnaye, in ‘Annals and Mag. ot Hist.’ vol. siii. 1854, p. 157 : see also Mr. Wallace’s much full01 count in vol. xx. 1857, p. 412, and in Ins Malay Archipelago.
69 Wallace, ‘The Malay Archipelago,’ vol. ii. 1869, p. 405.
C«.
4P. XIII.
DECORATION.
79
I
Will
tjj mention only one other bird, remarkable from n ®xti'enie contrast in colour between the sexes, § e*y tlie famous Bell-bird ( Chasinorhynehus niveus ) of the r 6lioa’ tlle note of can b<i distinguished at
0Ue distance of nearly three miles, and astonishes every tlig f flrst hears it. The male is pure white, whilst terr -ale is dusky-green; and the former colour with
]lul^utl'ial species of moderate size and inoffensive \v’ts is very rare. The male, also, as described by
Kmkt0n, bas a 8Piral tube> nearly tbree diclies^ m
blp^i 5 'vhich rises from the base of the beak. It is jet-
„ , — uses uuui uubc ui -
tuff,' dotted over with minute downy feathers. This palate ; and when not inflated hangs down on
'vitix ^ 'Je inflated with air, through a communication
of The genus consists of four species, the males
^ are very distinct, whilst the females, as de- Jf-d by Mr. Sclater in a most interesting
cl
i„M! -v resemble each other, thus offering au excellent gro‘|ace of the common rule that within the same do t/ ^le roalos differ much more from each other than iaa]ele.^males. In a second species ( C . nudicollis) the Vr,, 18 dkewise snow-white, with the exception of a ey(fs sPace of naked skin on the throat and round the <^h during the breeding-season is of a fine green and a third species ( C . tricarunculatus) the head
paper,
-uif Tt 1 y — - /
boc|v , . alone of the male are white, the rest of the is pr _ eiOg chesnut-brown, and the male of this species Vg
ar,<i the ■
y be o ,
l°agt0^ded with three filamentous projections half as “ , 5s the body — one rising from the base of the beak
Tli 6 ' W° °thers from the corners of the mouth.
‘ Coloured plumage and certain other ornaments of
70 Mr
'VdeijT Se,later» ‘Intellectual Observer,’ Jan. 1867. ‘ Waterton’s
™te. in +P’ p- Us- See also Mr. Salvin’s interesting paper, witli a he ‘Ibis,’ 1865, p. 90.
80
sexual selection: bikds.
PahT*
the males when adult are either retained for life or
periodically renewed during the summer and breedi"? season. At this season the beak and naked skin ab° the head frequently change colour, as with some hero1'" ibises, gulls, one of the bell-birds just noticed, &c. the white ibis, the cheeks, the inflatable skin of 1 throat, and the basal portion of the beak, then becO^ crimson.71 In one of the rails, Gatticrex cristatus a h"-'^ red caruncle is developed during this same period the head of the male. So it is with a thin horny C1 , on the beak of one of the pelicans, P. erythrorhynchl>s' for after the breeding-season, these horny crests ^ shed, like horns from the heads of stags, and the si)'’1, of an island in a lake in Nevada was found cover with these curious exuvke.72
dU
Changes of colour in the plumage according to season depend firstly on a double annual moult, secoo1"; on an actual change of colour in the feathers themself
!<*
and thirdly on their dull-coloured margius being per1' ically shed, or on these three processes more or
combined. The shedding of the deciduary margins be compared with the shedding by very young bA1 of their down ; for the down in most cases arises frC* I the summits of the first true feathers.73
With respect to the birds which annually undergo double moult, there are, firstly, some kinds, for inst#",. snipes, swallow-plovers (Glared®), and curlews, ^ which the two sexes resemble each other and do 11 . change colour at any season. I do not know whet^, the winter-plumage is thicker and warmer than 11
U 1 Land and Water,’ 1867, p. 394.
w Mr. D. G. Elliot,, in ‘Proo. Zool. Soc.’ 1869, p. 589. ^
73 ‘Nitzsck’s Pterylograpliy,’ edited by P. L. Selater. Bay ^ 18G7, p. 14.
DOUBLE ANNUAL MOULT.
81
Cir.
4P- Sin.
of'?.1T!er'PlumaoeJ which seems, when there is no change
^e°lour5 the most probable cause of a double moult, lot ly’ ^ler<: are birds, for instance certain species of „c mp antl 0l'101' grallatores, the sexes of which re-
an'l ’ 6 eacl1 otlier> but have a slightly different summer tl'VlIl^ei Piuma"e. The difference, however, in colour a<j ese cases is so slight that it can hardly be an to J^a§e to them ; and it may, perhaps, be attributed tli, 1*° ci'rect action of the different conditions to which
“e birds
tt
iero
are exposed during the two seasons. Thirdly, a]jj. are many other birds the sexes of which are Hatj’e’ but which are widely different in their summer St Xp "*nter plumage. Fourthly, there are birds, the
^ \V'Vt 1 f ilw dfIT.M* vn nnnT\ A"f l'l D V in mlnnr • Tvnt.
ath ^ Ibroughout the year, whilst the males undergo ep i;lnSe, sometimes, as with certain bustards, a great tli,? colour. Fifthly and lastly, there are birds
tliei?eXeS 0t which differ from each other in both de SUn»ner and winter plumage, but the male un-
°f which differ from each other in colour ; hut ouiales, though moulting twice, retain the same
goes ;
greater amount of change at each recurrent
^an ^be female— of which the Huff ( Machetes offers a good instance.
iu c , respect to the cause or purpose of the difference Uw ,°Ur between the summer and winter plumage, this cln?n? s°uie instances, as with the ptarmigan,74 serve feteng both seasons as a protection. When the dif- p6fi Ce between the two plumages is slight it may aPs he attributed, as already remarked, to the
'PUoL browu mottled Bummer plumage of the ptarmigan is of as '3t' in p(, ^Jr,rtanee to it, as a protection, as the white winter plumage ;
lnav'a! during the spring, when the snow has disappeared, Waited u hnown to suffer greatly from birds of prey, before it has bh<ls of 15 S SUtQmer dress : see Wilhelm von Wright, in Lloyd, 1 Game V0L ^edeiV 1S67, p. 125.
8 2 SEXUAL SELECTION: BIRDS. PAR?11'
direct action of the conditions of life. But with mo11) birds there can hardly be a doubt that the sumn1^ plumage is ornamental, even when both sexes are ali^e' We may conclude that this is the case with man)* herons, egrets, &c., for they acquire their beautii'1 plumes only during the breeding-season. Moreover such plumes, top-knots, &c., though possessed by bod1 sexes, are occasionally a little more highly developed 111 the male than in the female; and they resemble d1? plumes and ornaments possessed by the males al°”f of other birds. It is also known that confinement, W affecting the reproductive system of male birds, hf* quently checks the development of their second^') sexual characters, but has no immediate influence any other characters ; and I am informed by ^r‘ Bartlett that eight or nine specimens of the Kd° (: Tringa canutus) retained their unadorned winter mage in the Zoological Gardens throughout the ye‘‘ir' from which fact we may infer that the summer pluina?' though common to both sexes partakes of the nat»re of the exclusively masculine plumage of many otF’1 birds.75
From the foregoing facts, more especially fr01’1 neither sex of certain birds changing colour duri"' either annual moult, or changing so slightly that tb change can hardly be of any service to them, and the females of other species moulting twice yet rota'1' ing the same colours throughout the year, we may C°K elude that the habit of moulting twice in the year h1'
IT1 regard to the previous statements on moulting, see, on sa'P1,
&c., Macgillivmy, ‘Hist. Brit. Birds,’ vol. iv. p. 371; on Glare0’? curlews, and bustards, Jerdon, ‘ Birds of India,’ vol. iii. p. 615, ’ 683 ; on Totanus, ibid, p. 700 ; on the plumes of herons, ibhf 73S, and Macgillivray, vol. lv. p. 435 and 444, and Mr. Stafford Allc'
in the ‘ Ibis,’ vol. v. 1863, p. 33.
DOUBLE ANNUAL MOULT.
83
c«.
At>' Xlii.
^ been acquired in order that the male should assume K,'111? the breerlin^-season an ornamental character; ae lllal the double moult, having been originally I haired f01. some distinct purpose, has subsequently W-^en. advantage of in certain cases for gaining a J’t!al Plumage.
tli, + a?Pears at first sight a surprising circumstance lad 'v‘th closely-allied birds, some species should regu- sjri ^ Undergo a double annual moult, and others only a 0l, g 0 °ne. The ptarmigan, for instance, moults twice ^ thrice in the year, and the black-cock only IXo S01ae of the splendidly-coloured honey-suckers eoi0' tai'inj©) of India and some sub-genera of obscurely- ]lav°Ure<i pipits (Anthus) have a double, whilst others daf6 °nly a single annual moult.76 But the gra- <k'ci°nS - n tlle manner of moulting, which are known to gj.0 r witl1 various birds, shew us how species, or whole do,23 of species, might have originally acquired their l,aVp 6 ai>nual moult, or having once gained the habit, t]le !l8ain lost it. With certain bustards and plovers b6iIiVernal moult is far from complete, some feathers also'8 1enewed, and some changed in colour. There is rail ,!ea8°n to believe that with certain bustards and s0U) 1 '<J birds, which properly undergo a double moult, tlir,,6 tlle °Uer males retain their nuptial plumage lUav" i °nt the year. A few highly modified feathers as (Jl one be added during the spring to the plumage, OrS " bh the disc-formed tail-feathers of certain feat]f,°S ffliringa) in India, and with the elongated By er® 011 the back, neck, and crest of certain herons. c 1 steps as these, the vernal moult might be ren-
Olq
bnta|a > ^10 awaiting of tlie ptarmigan, see Gould’s ‘ Birds of Great 3Gg v1 honey-suckers, Jerdon, ‘ Birds of India,’ vol. i. p. 359, a the moulting of Anthus, see Blyth, in 1 Ibis,’ 1867, p. 32.
G 2
84
SEXUAL SELECTION: BIRDS.
PakT*
dered more and more complete, until a perfect double moult was acquired. A gradation can also be shewn 1° exist in the length of time during which eitl*el" annual plumage is retained; so that the one mig^ come to bo retained for the whole'year, the other beM completely lost. Thus the Machetes pugnax retail his raff in the spring for barely two months. Tbe male widow-bird ( Cliera progne) acquires in Natal ^ fine plumage and long tail-feathers in December °r January and loses them in March; so that they a1'0 retained during only about three months. Most specif which undergo a double moult keep their ornament111, feathers for about six months. The male, however, °! the wild Oallus bankiva retains his neck-hackles nine or ten months ; and when these are cast off, underlying black feathers on the neck are fully expo?1- to view. But with the domesticated descendant of tl)ls species, the neck-hackles of the male are immediate!) replaced by new ones; so that we here see, with respect to part of the plumage, a double moult changed undef domestication into a single moult.77
4 ho common drake (Anas boschas ) is well known aft0* the breeding-season to lose his male plumage for 11 period of three months, during which time he assun3^ that of the female. The male pintail-duck acuta) loses his plumage for the shorter period 0 six weeks or two months ; and Montagu remarks tb®
“ For the foregoing statements in regard to partial moults, an<l ^ old males retaining their nuptial plumage, sec Jenlon, on bustards < plovers, in ‘ Birds ol India,’ vol. iii. p. (;i7, 637, 709, 711. Also Sb, in ‘ Land and Water,’ 1867, p. 84. Oil the Yidua, ‘ Ibis,’ vol. iii- l8" i p. 133. On the Drongo shrikes, Jordon, ibid. vol. i. p. 435. On w vernal moult of the Herodias bubulcus. Sir. S. S. Allen, in ‘ Ibis,’ lS6J p. 33. On Gallus lanhiva, Blytli, in 1 Annals and Mag. of Nat. Bis,„ vol. i. 1848, p. 455 ; see, also, on this subject, my ‘Variation of under Domestication,’ vol. i. p. 236.
DOUBLE ANNUAL MOULT.
85
CiUp.
XIII.
« ^’s double moult within so short a time is a most „ ^ti'aordinary circumstance, that seems to bid defiance 0 all human reasoning.” But lie who believes in the o adual modification of species will be far from feeling
11 prise at finding gradations of all kinds. If the male Pintail
o o
^ were to acquire his new plumage within a still l°rter period, the new male feathers would almost ^essarily be mingled with the old, and both with e lne Proper to the female ; and this apparently is the tj^e with the male of a not distantly-allied bird, namely << 6 df erganser serrator, for the males are said to <; ^lldergo a change of plumage, which assimilates them
tsh
aecel
^pletely lost.78
some measure to the female.” By a little further Oration in the process, the double moult would be
'ome
b 8
coloured in the spring, not by a vernal moult, 0j, , either by an actual change of colour in the feathers, sli 7 t'1“r obscurely-coloured deciduary margins being j0 6 ‘ Changes of colour thus caused may last for a a ^er °r shorter time. With the Pelecanus onocrotalus br 7aUtiful rosy tint, with lemon-coloured marks on the th ast’ overspreads the whole plumage in the spring ; hut “ 7° t*Uts’ as ^r- Sclater states, “do not last long, dis- (( appearing generally in about six weeks or two months the 6r the>T Pave been attained.
- marc
male birds, as before stated, become more
Certain finches shed
KJ 1 tUtJir leailltUC) 111 Wi<3 Q|niug, uuu w '^liter-coloured, while other finches undergo no Sb t 'Jlli,nKe- Thus the Fringilla tridis of the United lju . es _(as well as many other American species), ex- tyjj.1, 8 its bright colours only when the winter is past, 1 st our goldfinch, which exactly represents this bird
on tj. ee VlaeglUivray, 1 Hist. British Birds ’ (vol. v. p. 31, 70, and 223), Xloj^ ^Woulting 0f f|ie Anatidss, with quotations from M aterton and SB- Also Yarrell, * Hist, of British Birds,’ vol. iii. p. 243.
86
SEXUAL SELECTION: B1KDS.
Paet 1
in habits, and our siskin, which represents it still m0l'e closely in structure, undergo no such annual chan?6' But a difference of this kind in the plumage of alii'- species is not surprising, for with the common linin’1’ which belongs to the same family, the crimson forehe®® and breast are displayed only during the summer 1,1 England, whilst in Madeira these colours are retain66 throughout the year.73
Display by Male Birds of their Plumage. — Ornament of all kinds, whether permanently or temporarily gained are sedulously displayed by the males, and apparently serve to excite, or attract, or charm the females. But the males will sometimes display their ornaments, wl^11 not in the presence of the females, as occasionally occur3 with grouse at their balz-places, and as may be noting with the peacock; this latter bird, however, evidently, wishes for a spectator of some kind, and will shew’ his finery, as I have often seen, before poultry or ev6’1 pigs.80 All naturalists who have closely attended to tl|6 habits of birds, whether in a state of nature or under confinement, are unanimously of opinion that the rod65 delight to display their beauty. Audubon frequently speaks of the male as endeavouring in various ways to charm the female. Mr. Goidd, after describing son)6 peculiarities in a male humming-bird, says he has 110 doubt that it has the power of displaying them to th6 greatest advantage before the female, Ur. Jordon :
79 On the pelican, see Selnter, in ‘Proc. Znol. Soo.’ 1868, p. ^ ' On the American (inches, see Audubon, ‘Ornith. Biography,’ vol. i-P- 174. 221, and Jerdon, ‘Birds of India,’ vol. ii. p. 888. On the l'r‘r gilla cannabina of Madeira, Mr. E. Vernon Harcourt ‘Ibis’ vol- v'’ 1863, p. 230.
so See also ‘ Ornamental Poultry,’ by Eev. E. S. Dixon, 1S48, p. 8-...
81 ‘ Birds of India,’ introduct. vol. i. p. xxiv. ; on the peacock, vol- 1"' p. 507. See Gould’s ‘Introduction to the Trochilidse,’ 1 861, p. la and l1*’
DISPLAY BY THE MALE.
87
Cii.
Ap.
XIII.
, ®lsts that the beautiful plumage of the male serves th ° *asclnate and attract the female.” Mr. Bartlett, at 0 Zoological Gardens, expressed himself to me in the ' railgest terms to the same effect.
<t 1 m«st be a grand sight in the forests of India “to (< /.?me suddenly on twenty or thirty pea-fowl, the males <; ‘splaying their gorgeous trains, and strutting about rJ11 aU the pomp of pride before the gratified females.” feUe wild turkey-cock erects his glittering plumage, ^Pands his finely-zoned tail and barred wing-feathers, t|l altogether, with his gorged crimson and blue wat- .(es’ ^akes a superb, though, to our eyes, grotesque 'Ppearauce. Similar facts have already been given u 1 Respect to grouse of various kinds. rl urning to pother Order. The male Rupicold crooea (fig. 50) is n 16 1°^ uiost beautiful birds in the world, being of T1 end id orange, with some of the feathers curiously plicated and plumose. The female is brownish- shaded with red, and has a much smaller dh ^ IT Schomburgk has described their court- ln'P; he found one of their meeting-places where ten jp'1 es iu'd two females were present. The space was ^ 0,11 l°ur to five feet in diameter, and appeared to have j(- '.u cleared of every blade of grass and smoothed as <( hv human hands. A male “ was capering to the .^Parent, deli ght of several others. Now spreading “i..8 "ings, throwing up its head, or opening its tail « 'e a Inn 5 now strutting about with a hopping gait a bred, when it gabbled some kind of note, and a as Relieved by another. Thus three ot them suc- « ^bveiy took the field, and then, with self-appro- 0].a ,1011’ withdrew to rest.” The Indians, in order to bioir skins, wait at one of the meeting-places are T are eagerly engaged in dancing, and then alfie to kill, with their poisoned arrows, four or five
88
SEXUAL selection: bikds.
Pakt*
males, one after the other.82 With Birds of Paradis® a dozen or more full-plumagcd males congregate in ‘l tree to hold a dancing-party, as it is called by tlie natives ; and here flying about, raising their wing3’
Kuptcoltt crocea, male (from Brelm).
elevating their exquisite plumes, and making the& vibrate, the whole tree seems, as Mr. Wallace re*
83 ‘Journal of R. Geograph, Soc.’ vol. s. 1S40, p. 236.
DISPLAY BY THE MALE.
89
C«.
Ap.
xiir.
eii,! S’ filled with waving plumes. When thus
’Uav^’ they be001116 so absorbed, that a skilful archer kei't S*l°ot 11 early the whole party. These birds, when to i i"1 eorvfinf'ment in the Malay Archipelago, are said
* * ]ttuch care jn keeping their feathers clean ; olten evJ-acbng them out, examining them, and removing pa- y sPeck of dirt. One observer, who kept several
* * a^Ve! did not doubt that the display of the male ’^tended to please the female.83
sliih 6 S°ld-pheasant (Thaumalea jaicta) during bis court- °nly expands and raises his splendid frill, but
fet(1 1 't, as I have myself seen, obliquely towards the
it, J 0 011 whichever side she may be standing, obviously
ker (JI' that a large surlace maybe displayed before
(fiff ddartlett has observed a male Polyplectron
...
;cimen
«. ^r
la the act of courtship, and has shewn me a
tail
"'l'1 g- feathers of this bird are ornamented with 0c°Ib, like those on the peacock’s train. Now etects | . Peacock displays himself, he expands and b0llt 1118 tad transversely to his body, for he stands in tilll{- .. the female, and has to shew ofi', at the same °fth’ d® rich blue throat and breast. But the breast
stuffed in the attitude then assumed. The
ure
--VU ViUC UllUcib (IUU VAUtVOl. J-UIU DliVy i/i vuuw
°lyplectron is obscurely coloured, and the ocelli
Polv °, Coufined to the tail- leathers. Consequently the ^ P tetrou docs not stand in front of the female; but °ts and expands his tail-feathers a little obliquely,
. XX
Also
\ 83 ( A
■Miaou and Mag. of Nat. Ilist.’ vol. xiii. 1854, p. 157; also
iseo’ bld- Vol. ■ '
h jjj > P 252
8<m 326-
j> mj. ij
3 aecoyn'j.yr;. ^Tp°il has given (‘The Student,’ April, 1870, p. 115) a ye"'®ided \) ° 'his manner of display, which he calls the lateral or ers,co tof' ’X the gold pheasant and by the Japanese pheasant, Ph.
vlag. of Nat. lost. vol. xm. 1804, p. 157 ; also ■ 1857, p. 412, and ‘The Malay Archipelago,' vol. io Dr. Bennett, us quoted by Brelnn, ‘ Thierleben,’
90
SEXUAL SELECTION: BIRDS.
Part !l'
lowering the expanded wing on the same side, raising that on the opposite side. In this attitude ^ ocelli over the whole body are exposed before the eV of the admiring female in one grand bespangled &
DISPLAY BY THE MALE.
91
Cit.
^ XIII.
Panse.
HerS8rrT“ l,UB oull(lueirueiu 1(111 “1C "“,""7
8,^ -‘-tie male Tragopan pheasant acts m nearly the
w- To whichever side she may turn, the expanded he,!gSrauc* the obliquely-held tail are turned towards
u - banner, for he raises the feathers of the body,
°ugh - - - -- •
t° the
'°ugh not the wing itself, on the side which is opposite finale, and which would otherwise be concealed, eXhib7 “eaiV a11 the beautifully-spotted feathers are
So
till
iat
Tl £d the same time.
'tv!!. case of the Argus pheasant, is #uu mwo duu,...^. arc ^'^cnsely developed secondary wing-feathers, which
seiy cieveiupea secouuaiy
honC°nfined t» the male, are ornamented with a row of
aitwi ‘ ...
4i
erdy to twenty-three ocelli, each above an inch in oh); r‘ t he feathers are also elegantly marked with 8ta‘ JUe daidf stripes and rows of spots, like those on the
ttl fyf' _ t t rm n *
so ° a tiger and leopard combined. The ocelli are taatfo?^ul]y shaded that, as the Duke of Argyll re- So y f° they stand out like a ball lying loosely within rit\L ®ut when I looked at the specimen in the
a
-But when I looked at tlie specim fcJ Museum, which is mounted with the ])°intfcC an(l trailing downwards, I was greatly disap- ltr p ’ for the ocelli appeared flat or even concave. fot ],g°, d’ however, soon made the case clear to me, p]avi had made a drawing of a male whilst he was dis- katj V' himself.
both 6„ -I— -
gate,] U11,f these, together with the enormously clon- V. at 'feathers, make a grand semicircular upright Poaitio °W as soon !iS the wing-feathers are held in this % h aud the light shines on them from above, the °UCe r act °f the shading comes out, and each ocellus at the8r, 'jVmbles the ornament called a ball and socket. have eathers have been shewn to several artists, aud all xPressed their admiration at the perfect shading.
Cj
Hjl u y-wseix. At such times the long secondary fcls hi both wings are vertically erected and ex-
85 ‘The Reign of Law,’ 1867, p. 203.
92
SEXUAL SELECTION: BILES.
PART1
It may well be asked, could suck artistically-sk^6 ornaments bare been formed by means of sexual tion? But it will be convenient to defer giving 1 answer to this question until we treat in the nc chapter of the principle of gradation.
The primary wing-feathers, whick in most gall'li:'_ ceous birds are uniformly coloured, are in the Atf , pheasant not less wonderful objects than the second
wing-feathers. They are of a soft brown tint numerous dark spots, each of which consists of two , three black dots with a surrounding dark zone. ^ I the chief ornament is a space parallel to the dark-*-1 . shaft, whick in outline forms a perfect second feat*1., lying within the true feather. This inner pa1'* \\ coloured of a lighter chesnut, and is thickly dot*^ with minute white points. 1 have shewn this featko* I several persons, and many have admired it even 111 | than the ball-and-socket feathers, and have declsM that it was more like a work of art than of nll*u . Now these feathers are quite hidden on all ordk ’
occasions, but are fully displayed when the long seC° dary feathers are erected, though in a widely difl manner ; for they are expanded in front like two - ^
ttk
fans or shields, one on each side of the breast near ground. I
The case of the male Argus pheasant is eminel1 , interesting, because it affords good evidence that
most refined beauty may serve as a charm f°r female, and for no other purpose. We must conn that this is the case, as the primary wing-featberS (f never displayed, and the ball-and-socket ornaments not exhibited in full perfection, except when the lJl‘ , assumes the attitude of courtship. The Argus phe^ does not possess brilliant colours, so that his succes^j courtship appears to have depended on the great *>te
DISPLAY BY THE MALE.
93
-«4t.
Sill.
Umes3 aQd on the elaboration of the most elegant t]lat(;1'ns' Many will declare that it is utterly incredible s]1;u|.u finale bird should be able to appreciate fine Hja|, Up a,1(l exquisite patterns. It is undoubtedly a f'Uin.' 0118 that she should possess this almost tlie 111 ^eSree of taste, though perhaps she admires }[,. ^<nei'al effect rather than each separate detail, ^tir 10 that lie can safely gauge the discrimi-
tll6 ail(f taste of the lower animals, may deny that ma^e Argus pheasant can appreciate such refined tip ’ but he will then be compelled to admit that efcxtraor-
of
tlie ! :;, laoi‘dinary attitudes assumed by the male during l(is ^ of courtship, by which the wonderful beauty of
this •. mage is fully displayed, are purposeless; and a conclusion which I for one will never admit.
b
i^sj' so many pheasants and allied gallinaceous tbe ,. Cai'eMlly display their beautiful plumage before raleS) ^ ’s reinav^ft^^e» as Mr. Bartlett informs tluj(4^'at this is not the case with the dull-coloured P]hl .. ail(f Cheer pheasants ( Crossoptilon auritum and «ci0. <a>lUs Walliohii ) ; so that these birds seem con- IWi5 ,^'at they have little beauty to display. Mr.
'^rtW i - »...*»
sp6cies • Jlas llever 8een the males of either of these
gCKjfi68 ^'Sbting together, though ho has not had such
VU°P P 0 r tu ni t i es for observing the Cheer as the
nil ^ Pheasant, Mr. Jenner Weir, also, finds that
P1U * 6 turds with rich or strongly-characterised
sPecieg are more quarrelsome than the dull-coloured
bne)|’s belonging to the same groups. The gold- ’■ n tor '
li:
>et
instance, is far more pugnacious than the
'vbici1’ Ulu^ the black-bird than the thrush. Those birds ''iso 1, llU|Mrgo a seasonal change of plumage like- they ,GC(,me much more pugnacious at the period when 5,0 most gaily ornamented. No doubt the males
of
lU° obscurely-coloured birds fight desperately
94
SEXUAL SELECTION : BIKDS.
Pab1 1
together, but it appears that when sexual select^ has been highly influential, and has given bri? , colours to the males of any species, it has also
often
W
given a strong tendency to pugnacity. j shall meet with nearly analogous cases when we of mammals. On the other band, with birds the po"'^ of song and brilliant colours have rarely been h\.
t,l"f
,11/
acquired by the males of the same species ; but i» case, the advantage gained would have been identic^ the same, namely success in charming the fen1" j Nevertheless it must be owned that the males of sev"1'
brilliantly-coloured birds have had their feathers f! j cially modified for the sake of producing instruxne®^ music, though the beauty of this cannot be compnre j at least according to our taste, with that of the v°L’ music of many songsters.
We will now turn to male birds which are
nflt
ornamented in
any very high degree, but "'1'“ , nevertheless display, during their courtship, what® attractions they may possess. These cases are in so"1 respects more curious than the foregoing, and have *•> j but little noticed. I owe the following facts, se^eCqr, from a large body of valuable notes, sent to me by ^ Jenner Weir, who has long kept, birds of many kinds* eluding all the British Friugilikke and Emberizidffi. -* bullfinch makes his advances in front of the fen1"
crimson feathers arc seen at once than otherwise 'v<
and then puffs out his breast, so that many more o* - j
9
be the case. At the same time he twists and bows black tail from side to side in a ludicrous manner.
rp|j<?
male chaffinch also stands in front of the female, shewing his red breast, and “blue bell, ” as the fa»"" call his head ; the wings at the same time being sli- 1 k expanded, with the pure white bands on the shorn1 ,, thus rendered conspicuous. The common linnet diste
DISPLAY BY THE MALE.
95
4Up
XIII.
his ,,
tail °S^ ')reast, slightly expands his brown wings and ’ s° as to
*hite el,'ding lS°me birdi
make the best of them by exhibiting their
' ef gmgs. \Ve must, however, bo cautious in con- us ^ the wings are spread out solely for display, s act thus whose wings are not beautiful.
Thi
tile • Ule case with the domestic cock, but it is always 6Xpai W 0U ^le °PP0Site to the female which is The Ir, , an<i at the same time scraped on the ground. fincjlf^a e goldfinch behaves differently from all other bl(ic]? S ' . his wings are beautiful, the shoulders being "hit ’ ii|e dark-tipped wing-feathers spotted with ■he f, “ J
ail(i edged with golden yellow. When he courts
ai®! he sways his body from side to side, and Gue tlll'ns his slightly expanded wings first to -\'o 0^e ihen to the other, with a golden flashing effect. Vin? ^ hnch, as Mr. Weir informs me, turns
t>ot
tl:
courtship from side to side in this manner ;
j -I 1 1 ?
.. . > TJle closely-allied male siskin, for lie would not
Sf0st to his beauty.
hut ^ British Buntings are plain -coloured birds;
the feathers on the head of the male
re
W£.sK--- . .
c.olOUr lng (Emberiza sehoeniculus ) acquire a fine black
hictu ,J- die abrasion of the dusky tips: and these ar
..X** ,
>lofis j Ies of Amadina from Australia : the A. casta- adarl a Very small and chastely-coloured finch, with 6ucH r,c l,’ "hite rump, and jet-black upper tail-coverts,
%
hvo Sjv' u.lll Ing fbe act of courtship. Mr. Weir has kept
n ‘ ^ J CAU
. die latter
beim
marked with three large
^I'tinrr 18 0V:d spots of white.86 This species, when diegg 15 die female, slightly spreads out and vibrates ^^ner ^ ^‘Coloured tail-coverts in a very peculiar The male Amadina Lathami behaves very
-vop ^
of a e ascription of these birds, see Gould’s ‘ Handbook to the
w&tralra,’ vol. i865, 417.
96
SEXUAL SELECTION: BIRDS.
pA»T
P'
tl'1'
differently, exhibiting before the female his brillia33^ spotted breast and scarlet rump and scarlet upper 1 coverts. I may here add from Dr. Jerdon, that the dian Bulbul ( Pycnonotus hmmorrhous) has crimson U® tail-coverts, and the beauty of these feathers, it mb be thought, could never be well exhibited ; but bird “ when excited often spreads them out later* ' “so that they can be seen even from above.” 81 .J common pigeon lias iridescent feathers on the br^J and every one must have seen how the male inflate® breast whilst courting the female, thus showing off feathers to the best advantage. One of the bean*1 bronze-winged pigeons of Australia ( Oct/phaps behaves, as described to me by Mr. Weir, very di ently : the male, whilst standing before the fi"3331 i lowers his head almost to the ground, spreads out raises perpendicularly his tail, and half expands I wings. He then alternately and slowly raises and 1
presses his body, so that the iridescent metallic featl3® I
are all seen at once, and glitter in the suu.
Sufficient facts have now been given to shew " i
b »I»I
what care male birds display their various charms,
this they do with the utmost skill. Whilst p3’eell'|j< their feathers, they have frequent opportunities lor
their beauty. But as all the males of the same spet
miring themselves and of studying how best to eS
display themselves in exactly the same
bi3^
.ttirf
appears that actions, at first perhaps intentional, become instinctive. If so, we ought not to accuse of conscious vanity ; yet when we see a peacock stru1 ^ about, with expanded and quivering tail-leathm'S, seems the very emblem of pride and vanity.
The various ornaments possessed by the male®
87 ‘ Birds of India,’ vol. ii. p. 96.
DISPLAY BY THE MALE.
97
C«.
At' xur.
^tai;
ha*e b,
°f tlie highest importance to them, for they
gtoatl e-6U ae(lu*re(l iQ some cases at tlie expense of 4fr- -v ^upeded powers of flight or of running. The "ight-jar ( Cosmetornis ), which during the pair- l°pe^a8°n ^'as one primary wing-feathers deve-
^tai- ilnto a streamer of extreme length, is thus much ab]e ' ' \n its flight, although at other times remark- SeCo °r its swiftness. The “ unwieldy size ” of the are lcary wing-feathers of the male Argus pheasant Xb6 j!^ <£ almost entirely to deprive the bird of flight.” ^h'iricy16 PW of male Birds of Paradise trouble them of |] '' a high wind. The extremely long tail-feathers 6 'ruilo widow-birds (Yidua) of Southern Africa cast o> ^eir flight heavy ; ” but as soon as these are Wed ^UeP iiy as well as the females. As birds always Dot . ^en i'00fl is abundant, the males probably do
ft0a a('r much inconvenience in searching for food 11 theii ■
h
■ardiv l 1 r — “■ ■' > — — - —
to b^ Je a floubt that they must be much more liable
tL down by birds of prey. Nor can we doubt
tl]G lonn
lr impeded powers of movement ; hut, there can
and
th,
Wm
g train of the peacock and the long tail ^'feathers of the Argus pheasant must render 'vouj ^ a lri°re easy prey to any prowling tiger-cat than of inari01'lCrw,'se Hie case. Even the bright colours otogs ^ ^ale birds cannot fail to make them conspi- h Ug a Iheir enemies of all kinds. Hence it probably r' ^ould has remarked, that such birds are ^ °* a sl>y disposition, as if conscious that their cult t0 Vj as a source of danger, and are much more diffi- lscover or apiproach, than the sombre-coloured H'u] „ 1Paratively tame females, or thau the young
etn
yet unadorned males.*
u , Oh +1.
1865 6 ^0srQetornis, see Livingstone’s 1 Expedition to the Zam- ^Otj, t’tP- the Argus piieasant, Jardine’s 4 Nat. Hist. Lib. :
98
SEXUAL SELECTION : BIEDS.
PiS* 1
It is a more curious fact that the males of some hi1' ^ which are provided with special weapons for battle, which in a state of nature are so pugnacious that tl)£’- often kill each other, suffer from possessing eert^ ornaments. Cock-fighters trim the hackles and cut 0 the comb and gills of their cocks ; and the birds fl' then said to be dubbed. An undubbed, bird, as , Tegetmeier insists, “is at a fearful disadvantage:
“ comb and gills offer an easy hold to his adversatl ' “beak, and as a cock always strikes where he hoi “ when once he has seized his foe, he has him entire*J “in his power. Even supposing that the bird is “ killed, the loss of blood suffered by an undubbed fOc “ is much greater than that sustained by one that J1^ “ been trimmed.” 89 Young turkey-cocks in fight'11-' always seize hold of each other’s wattles ; and I l)rC"
surne that the old birds fight in the same manner.
If
may perhaps be objected that the comb and wattles not ornamental, and cannot be of service to the b'1 > in this way ; but even to our eyes, the beauty the glossy black Spanish cock is much enhanced by ( white face and crimson comb ; and no one who has 0 ^ seen the splendid blue wattles of the male Trag°l'. pheasant, when distended during the act of courtsH
can for a moment doubt that beauty is the object g'1 From the foregoing facts we clearly see that the p
lufl
and other ornaments of the male must be of the In
<rlk
i i'1
importance to him; and we further see that beauty some cases is even more important than success in bar
Birds,’ vol. xiv. p. 167. On Birds of Paradise, Lesson, quoted by t'Y jt ‘ Thierleben,’ B. iii. s. 325. On the widow-bird, Barrow’s ‘ Tr»w ^ Africa,’ vol. i. p. 243, and ‘ Ibis,’ vol. iii. 1861, p. 133. Mr. Gcu1 j. the shyness of male birds, ‘Handbook to Birds of Australia,’ v 1865, p. 210, 457.
33 Tegetmeier, 1 The Poultry Book,’ 1866, p. 139.
Ch.
Ap. XIV.
sexual selection: birds.
99
CHAPTER XIV.
Ch,
Birds — continued.
w
Ol(»g '
, exerted by the female — Length of court ship — Unpaired 0)lr s~7 Mental qualities and taste for the beautiful — Preference ^antipathy shewn by the female for particular males — Vari- tjf ' °f birds — Yariations sometimes abrupt — Laws of varia-
p U formation of ocelli — Gradations of character — Case ol c°ck, Argus pheasant, and Urosticte.
Ben tlie sexes differ in beauty, in the power of
inert ’ 0r producing what I have called instru- fc3fc ,a tausic, it is almost invariably the male which seeil S the female. These qualities, as we have just are evidently of high importance to the male.
is aj'n they are gained for only a part of the year, this iq..i ' a-Vs shortly before the breeding-season. It is the
tii
or
i a'°ne who elaborately displays his varied attrac- ’ aad often performs strange antics on the ground
°hs,
11 ^je air, in the presence of the female. Each eia-J llVes away or> if he can, kills all his rivals.
n,
^ale
We
may conclude, that it is the object of the
+ f • J * >1
this ° ln<tuce the female to pair with him, and for
Way
Purpose }le tries to excite or charm her in various
Caref ’an,-i this is the opinion of all those who have ;V' studied the habits of living birds. But there oq go 8 a question which has an all important bearing satqe Ua . Section, namely, does every male of the ho^ 8Pe°ies equally excite and attract the female ? or Ibegti 6 exert a choice, and prefer certain males? This 011 can be answered in the affirmative by much
H 2
100
SEXUAL SELECTION : BIEDS.
PABI ^
direct and indirect evidence. It is much more difib’1 * * * * *^ to decide what qualities determine the choice oi \ females ; but here again we have some direct and 1 direct evidence tliat it is to a large extent the extern*1 attractions of the male, though no doubt his vig°n* courage, and other mental qualities come into pi9?* We will begin with the indirect evidence.
Length of Courtship. — The lengthened period dun"' which both sexes of certain birds meet day after dW at an appointed place, probably depends partly on courtship being a prolonged affair, and partly on the f® iteration of the act of pairing. Thus in Germany al1 Scandinavia the balzens or leks of the Black-cock*1" last from the middle of March, all through April May. As many as forty or fifty, or even more bn'1 congregate at the leks; and the same place is often bL quented during successive years. The lek of the Cape'’ cailzie lasts from the end of March to the middle even end of May. In North America “the partri'-sj dances” of the Tetrao phasianellus “last for a mo® or more.” Other kinds of grouse both in North A11.'1” rica and Eastern Siberia1 follow nearly the same hab* The fowlers discover the hillocks where the Buffs c°^ gregate by the grass being trampled bare, and this sbe"j that the same spot is long frequented. The Indian® Guiana are well acquainted with the cleared are*"^, where they expect to find the beautiful Cocks of 1 1 . Bock; and the natives of New Guinea know the B'b where from ten to twenty full-plumaged male Bh'(b
1 Nordnmnn describes Bull. Soc. Imp. des Nat. Moscow,’ 186b ^
xxxiv. p. 2(14) the balzen of Tetrao urogalloides in Amur Laud- ^
estimated the number of assembled males at above a hundred) i
females, which lie hid in the surrounding bushes, not being cou® -
The noises uttered differ from those of the T. urogutlm or the
cailzie.
Cn
'ip. Xiy.
LENGTH OP COURTSHIP.
101
aradise congregate. In this latter case it is not ex- b 8sv stated that the females meet on the same trees, hunters, ^ not specially asked, would not pro- le8s mention their presence, as their skins are value- d-gate, during the breeding-season, and perform for g0i* lileir graceful evolutions. Large numbers of the ^“fy snipe ( Scolopax major) assemble during the
♦i.„ ' 111 a morass ; and the same place is frequented for le sa
^ay h
Affine htt,
Small parties of an African weaver ( Ploceus ) con-
Sclme purpose during successive years; here they
e seen running about “ like so many large rats, s out their feathers, flapping their wings
and
tke strangest cries.2 b°me of
capercailzie, pheasant-grouse, the rutt, the
bla!?me of the above-mentioned birds, namely, the
B^'Cock.
^i'tar
b,
'rive ^l0,1gbt that the stronger males would simply tat- c riVea away the weaker, and then at once have
polygamists. With such birds it might have
beiiev y Snipe, and perhaps some others, are, as it is
the dri'
it |0e . Possession of as many females as possible ; but if tei). .^‘dispensable for the male to excite or please the ’ '"e can understand the length of the courtship Sc,*-. Je congregation of so many individuals of both 8 at the
<%ale
%
LUo same spot. Certain species which are ibiN ,‘V m°nogamous likewise hold nuptial assemblages ;
tb,
Sfcerns to be the ease in Scandinavia with one of
of jj? arim'gans, and their leks last from the middle b|t(1 are'i to the middle of May. In Australia the lyre- 01 ^lenura superba forms “ small round hillocks,”
to the assemblages of the above named grouse see ’ > aieilebeHj' B. iv. s. 350; also L. Lloyd, ‘Game Birds of
P. 3C2 1 1867, p. i9i 78i Richardson, ‘ Fauna Bor. Americana,’ Birds, , «eT’°Usl .etL‘rences in regard to the assemblages of other birds have a kat, jr. e,en given. On Paradisea see Wallace, in ‘ Annals and Mag. lst-’ vol. xx. 1857, p. 412. On the snipe, Lloyd, ibid. p. 221.
102
SEXUAL SELECTION: BIRDS.
PakT ll'
and the M. Alberti scratches for itself shallow holes, 0,1 as they are called by the natives, corroborying placeS' where it is believed both sexes assemble. The mee, ings of the M. superla are sometimes very large ; al1 an account has lately been published3 by a travell etj who heard in a valley beneath him, thickly cove*'60 with scrub, “a din which completely astonished ” l|1!l’ ' on crawling onwards he beheld to his amazement abo1’ one hundred and fifty of the magnificent lyre-coc^ “ranged in order of battle, and fighting with “ scribable fury.” The bowers of the Bower-birds il1 the resort of both sexes during the breeding-seasO'1 ’ and “here the males meet and contend with each otl|t>f “for the favours of the female, and here the lathj, “ assemble and coquet with the males.” With t " ° the genera, the same bower is resorted to during mid-
years.4
The common magpie (Corvus pica, Linn.), as I ha' been informed by the Kev. W. Darwin Fox, used * assemble from all parts of Delamere Forest, in ord to celebrate the “ great magpie marriage.” So01^ years ago these birds abounded in extraordinary B'j1® bers, so that a gamekeeper killed in one inornfi^
nineteen males, and another killed by a single
seven birds at roost together. Whilst they were s° numerous, they had the habit very early in the sp^ of assembling at. particular spots, where they could seen in flocks, chattering, sometimes fighting, busth1'- and flying about the trees. The whole affair evidently considered by the birds as of the hig^ y importance. Shortly after the meeting they all seP . rated, and were then observed by Mr. Fox and otl*f>r'
3 Quoted by Mr. T. W. Wood in tho ‘ Student,’ April, 1870, p- Wg,
1 Gould, ‘ Handbook of Birds of Australia,’ vol. i. p. 300, 30S, 451. On the ptarmigan, above alluded to, see Lloyd, ibid. p. 129-
UNPAIRED BIRDS.
103
c«.
4p- Xiv.
^ bs Paired for the season. In any district in which I^Peeies does not exist in large numbers, great assem- lriages cannot, of course, be belli, and the same species iu',y llave different habits in different countries. For ® ance, I have never met with any account ot regular
sfcnTblages of black game in Scotland’ yet these as‘
m ,lages are so well known in Germany and Scau- a'ia that they have special names. t “"'Wired Birds.— From the tacts now given, we G°Qclude that with birds belonging to widely-dif- Cut gl011Ps their courtship is often a prolonged, deli- ng’ itu'i troublesome affair. There is even reason to ‘pact, improbable as this will at first appear, that tij 1(5 ra;des and females of the same species, inhabiting jjj6 SaiUe district, do not always please each other and pui?.11Se<l'ience do not pair. Many accounts have been |J6r lslled of either the male or female of a pair having he'n sb°t, and quickly replaced by another. This has observed more frequently with the magpie than ap 1 any other bird, owing perhaps to its conspicuous thitear&nC6 and nest- The illustrious Jenner states 1,1 Wiltshire one of a pair was daily shot no less «* seven times successively, “but all to no purpose, Mi\ i''e renaaining magpie soon found another mate;” is r le last pair reared their young. A new partner -jjgcneraliy found on the succeeding day ; but -Mr. eVe uh8°n gives the case of one being replaced on the hatr}.ng tbe same day- Even after the eggs are "'ill et ’ b °ne of the old birds is destroyed a mate of often be found; this occurred after an interval §lt j° days, in a case recently observed by one of • Lubbock’s keepers.5 The first and most obvious 5 o
W ,l?.aSPies, Jenner, in ‘Phil. Transact.’ 1824, p. 21. Maegil- »lag. of British Birds,’ vol. i. p. 570. Thompson, in * Annals and Xat- Hist.’ vol. viii. 1842, p. 494.
104
SEXUAL SELECTION: BIEDS.
Past*
conjecture is that male magpies must be much 511 °lf numerous than the females ; and that in the above case6’ as well in many others which could be given, the alone had been killed. This apparently holds good P some instances, for the gamekeepers iuDelamere F °,-e assured Mr. Fox that the magpies and carrion-cro"5 which they formerly killed in succession in large bers near their nests were all males; find they “F counted for this fact by the males being easily hd‘c' whilst bringing food to the sitting females. Maeg1’ livray, however, gives, on the authority of an excelF11' observer, an instance of three magpies successive^ killed on the same nest which were all females; 031 another case of six magpies successively killed wb$ sitting on the same eggs, which renders it probafr^ that most of them were females, though the male sit on the eggs, as I hear from Mr. Fox, when ^ female is killed.
iSir J . Lubbock’s gamekeeper has repeatedly shot, bc how many times he could not say, one of a pair of jil^ ( Garrulus glandarius), and has never failed shoi'd- atterwards to tind the survivor rematched. The L*3' W. I). Fox, Mr. F. Bond, and others, have shot one pair of carrion-crows ( Corvus cor one), but the nest soon agai
«
ill'
u tenanted by a pair. These birds are ratk^ common; but the peregrine falcon ( Falco peregrin is rare, yet Mr. Thompson states that in Ireland “ either an old male or female be killed in the bree1 “ ing-season (not an uncommon circumstance), anotbe* “ mate is found within a very few days, so that “ eyries, notwithstanding such casualties, are sure t0 “ turn out their complement of young.” Mr. Jen®^ Weir has known the same thing to occur with the pe^ griue falcons at Beachy Head. The same obsei've’ informs me that three kestrels, all males ( Falco iv0&
UNPAIRED BIRDS.
105
Cn.
Ap. V
Xiv.
^lus\
the ’ Were billed one after the other whilst attending SaiDe Dest 5 two of these were in mature plumage, hV(;i . third in the plumage of the previous year. ^r ty'Vit'h the rare golden eagle {Aquila chrysaStos), iu ^ Irhheek was assured bv a trustworthy gamekeeper So !?tland> that i] 1 one is killed, another is soon found. <«h the white owl ( Btrix jlammea), it has been ' th Vf>^ that “the survivor readily found a mate, and ^ laisehief went on.”
a.(]c}s Jte of Selborne, who gives the case of the owl, NrirlJ1 h? W a man, who from believing that %htjC '^tS "hen paired were disturbed by the males Wido’1-’ US(,d to shoot them ; and though he had S(JOll Ved the same female several times she was always m^ptovided With a fresh partner. This same natu- taartj 0l’hered the sparrows, which deprived the liouse- M’as j ls °t their nests, to be shot : but the one which “ ai1(j ’ “ he it cock or lien, presently procured a mate, ° '°r several times following.” 1 could add ana- feds^ar °ases relating to the chaffinch, nightingale, and ^t'ci n ■ ^'th respect to the latter bird ( Phoenicura eoitttn0 • tke W1'ifer remarks that it was by no means SlJrpri. j1U neighbourhood, and he expresses much hial • l0vv the sitting female could so soon give effec- T4C« that she was a widow. Mr. .Tenner Weir has
Stic
h,
never
lleci to me a nearly similar case: at Blackheath
"hen or SeeS °r heai’s the note of the wild bullfinch, yet Coik\se » °' his caged males has died, a wild one in the ''Sr |j. a h'w days has generally come and perched Vcl, r "'Towed female, whose call-note is far from tl)is "hi give only one other fact, on the authority ^garil'a<i °kserver ; one of a pair of starlings (Sturnus 'VS fQ "as shot in the morning ; by noon a new mate fair 111 > this was again shot, but before night the
Wag
complete ; so that the disconsolate widow or
106
SEXUAL SELECTION: BIEDS.
PABl"
widower was thrice consoled during the same day. ® t Engleheart also informs me that he used during sc''^r ^ years to shoot one of a pair of starlings which built ^ _ hole in a house at Blackheath ; but the loss was al""!'. immediately repaired. During one season he hep , account and found that he had shot thirty-five birds 1’ ' the same nest ; these consisted of both males and males, but in what proportion he could not say: D®’ theless after all this destruction, a brood was reared- J These facts are certainly remarkable. How is it r , ; so many birds are ready immediately to replace »
mate ? Mae
jpies, jays, carrion-crows, partridges, some other birds, are never seen during the spring a i themselves, and these offer at first sight the | perplexing case. But birds of the same sex, alth°lk, of course not truly paired, sometimes live in pairs 01 . small parties, as is known to be the case with pigeC> . and partridges. Birds also sometimes live in trip*6 as has been observed with starlings, carrion-crows, Fh rots, and partridges. With partridges two females ^ been known to live with one male, and two males ^ ( one female. In all such cases it is probable that union would be easily broken. The males of birds may occasionally be beard pouring forth love-song long after the proper time, shewing that * . have either lost or never gained a mate. Death accident or disease of either one of a pair, would the other bird free and single ; and there is reas0'1 ^ believe that female birds during the breeding-®®8^
• jiff'
« On the peregrine falcon see Thompson, ‘ Nat. Hist, of Birds,’ vol. i. 1819, p. 39. On owls, sparrows, and partridges, see ‘ Nat. Hist, of Selborae,’ edit, of 1825, yol. i. p. 139. On the r%,n. cura, see London’s ‘ Mag. of Nat. Hist.’ vol. vii. 1834, p. 245. riel (‘ Thierleben,’ B. iv. s. 991) also alludes to cases of birds thrice during same day.
UNPAIRED BIRDS.
107
V XIV.
"'hi iSpecially liable to premature death. Again, birds f6j. e ^'av'e bad their nests destroyed, or barren pairs, or tlioij ^ ^'“H'iduals, would easily be induced to desert „lair ,nates, and would probably be glad to take what off- 6 . 1,!ley could of the pleasures and duties of rearing ajA1,'1 lriK> although not their own.7 Such contingencies Xtv'°se probably explain most of the foregoing cases.6 di^^less it is a strange fact that within the same tlwlet> during the height of the breeding-season, sl*ould be so many males and females always fsiir.]" to repair the loss of a mated bird. Why do not W,. } 8Pare birds immediately pair together? Have Oi-'oi,'0* s°me reason to suspect, and the suspicion has a<-t f ^ to Jenner Weir, that inasmuch as the lojj,,0 Courtshrp appears to be with many birds a pro- th*^et an,l tedious affair, so it occasionally happens tlle eertain males and females do not succeed during co^Per season, in exciting each other’s love, and <6^tly ci0 uot pajr ? This suspicion will appear 'v Jat less improbable after we have seen what
>et i ’ eilr'y i n the season, of small coveys of mule partridg f the ,.aVe heard other instances. See Jenner, on the re-
p. 140) on the idges, of which tanled state
hite (< Nat. Hist, of Selbome,’ 1825, vol. i.
tar1 - w. - of
h lo ^'Uuivc organs in certain birds, in ‘Phil. Transact. 1824.
iu triplets, I owe to Mr. ,) enner Weir the oases , 11 ai‘d parrots, and to Mr. Fox, of partridges ; on carrion-
‘Field?
I
’ ‘"'lowing case has been given (‘The Times? Aug. 6th. 1868)
the rl"ta,' 1808, p. 415. On various male birds singing Atn,.A f'-oper jieriod, see Rev. L. Jenvus, ‘ Observations iu Natural
1*?’ 1816, p. 87.
* a, A 7 hy 6 &
w’.’^ter u! ‘ Morris, on tho authority ot‘ the Hon. and Rev. O. W .
von ^le Slimcikeeper here found a hawk’s nest this year, with ..MthiJg ones in it. He took four and killed them, but left one
,, "ete botl"11?8 "''Plied as a decoy to destroy tire old ones by. They A1'1; kee, J 6 lot TKxt day, in the act of feeding the young one, and , pd WTAWM it was done with. Tho next, day he c»me again lin„ ^ tw° other charitable hawks, who had come with an adopted succour tire orphan. These two he killed, and then left Ou returning afterwards lie found two more charitable
the
' to
lest.
108
SEXUAL SELECTION : BIRDS.
PA**"
strong antipathies and preferences female birds °cc9 sionally evince towards particular males. .
Mental Qualities of Birds, and their taste Jot f beautiful. — Before we discuss any further the quest'1', whether the females select the more attractive a,, or accept the first whom they may encounter, it wi^ advisable briefly to consider the mental powers of b>r j Their reason is generally, and perhaps justly, as low ; yet some facts could be given 9 leading to f opposite conclusion. Low powers of reasoning? I'^V ever, are compatible, as we see with mankind, ^ strong affections, acute perception, and a taste for ^ beautiful; and it is with these latter qualities tlitd arc here concerned. It has often been said that parrL become so deeply attached to each other that ^
one dies the other for a long time pines : but
Jenner Weir thinks that with most birds the streO? of them affection has been much exaggerated. Ne'e. theless when one of a pair in a state of nature ly been shot, the survivor has been heard for days . wards uttering a plaintive call; and Mr. St. j gives 10 various facts proving the attachment of birds. Starlings, however, as we have seen, may consoled thrice in the same day for the loss of mates. In the Zoological Gardens parrots have cleftI
“ individuals on the same errand of mercy. One of these he k^d the olher he also shot, but could not find. No more came on tb®
“ fruitless errand."
9 -For instance, Mr. Yarrell states (‘Hist. British Birds,’ vol. ii‘- p. 585) that a gull was not able to swallow a small bird which kad jy given 1o it. The gull “ paused for a moment, and then, as if “ recollecting himself, ran off at full speed to a pun of water, sh«f ,,, “ bird about m it until well soaked, and immediately gulped it d°. J “ Since that time he invariably has had recourse to the same espcdl “ in similar cases."
19 ‘A Tour in Sutherlaudshirc,’ vol. i. 1S49, p. 185.
MENTAL QUALITIES.
109
C8.
Ap,
XIV.
Soi,°8nised their foi-mer masters after an interval of lllonths. Pigeons have such excellent local me-
for,
that
,uri - they have been known to return to their 1 ]j er Monies after an interval of nine months, yet, as Mr. Harrison Weir, if a pair which would . v remain mated for life be separated for a few the tS <lUl ilJS tho winter and matched with other birds, w 'V.Q» when brought together again, rarely, if ever, E186 each other.
"ill f 8 SOmetimes exhibit benevolent feelings ; they
i'foi 18 Per'lal)s ought to be considered as a mistaken pajtllc*; They will also feed, as shewn in an earlier v.'hj,. this work, adult birds of their own species acJ>e become blind. Mr. Buxton gives a curious
ctj *nt of a parrot which took care of a frost-bitten and arjd ,ec T>ird of a distinct species, cleansed her feathers eUded her trom the attacks of the other parrots laole ,0:' lu°d freely about his garden. It is a still Llu''°us fact that these birds apparently evince a i)ilit,SyTriPathy for the pie asures of their fellows. When " r °f coc] ' ■ ' ' J
1 "hculous to see the extravagant interest taken Matter by the others of the same species.”
“ ■ eockatoos made a nest in an acacia tree,
"’as
it
'Tb
the
fose
l’ai'rots, also, evinced unbounded curiosity, and Sim Ul^ l< idea of property and possession.” 11 ^atgij 8 P°Ssess acute powers of observation. Every
8tati
®tai
lrt*, of course, recognises its fellow. Audubon ^t6g ^at with the mocking-thrushes of the United hie v / ^l'nus pohjfflothis) a certain number remain all tpJe<Vh r°ii]id in Louisiana, whilst the others migrate Wstern States; these latter, on their return,
to
n .
ip ACl
of Parrots,’ by 0. Buxton, M.P. Nov. 1868, p. 381.
‘ Annals and
110
SEXUAL SELECTION : BIKDS.
PaB1
gb^1
are instantly recognised, and always attacked, by ^ Southern brethren. Birds under confinement distl .
« ml I
guish different persons, as is proved by the strong * permanent antipathy or affection which they without any apparent cause, towards certain in® duals. I have heard of numerous instances with J^f partridges, canaries, and especially bullfinches. ' H Hussey has described in how extraordinary a no^^J a tamed partridge recognised everybody; and its h’d and dislikes were very strong. This bird seemed “ ^ I “ of gay colours, and no new gown or cap could be 1 ( “on without catching his attention.” 12 Mr. HefLl has carefully described the habits of some ducks ( I '•-'ntly descended from wild birds), which, at thy^ I
proach of a strange dog or cat, would rush headlong 1,1 to escape; but they knew so well Mr. Hewitt’s °'
C " ‘ » ’ **V^**«-D M
the water, and exhaust themselves in their attest
dogs and cats that they would lie down and bask i’1
sun close to them. They always moved away strange man, and so they would from the lady attended them, if she made any great change „ dress. Audubon relates that he reared and tatfe‘
wild turkey which always ran away from any dog ; this bird escaped into the woods, and some <•* afterwards Audubon saw, as he thought, a wild and made his dog chase it; but to his astonish!'1' ^ the bird did not run away, and the dog, when he cyb up, did not attack the bird, for they mutually re<
nised each other as old friends.13
Mr. Jenner Weir is convinced that birds pay P iP cular attention to the colours of other birds, sometl"
12 ‘ The Zoologist,’ 1847-1 SIS, p. 1602.
13 Hewitt on wild duets, ■ Journal of Horticulture,’ Jan. 13, y jf 39. Audubon on the wild turkey, 1 Ornith. Biography,’ voh >• * ' On the mocking thrush, ibid. vol. i. p. 1 10.
'"ip.
XIV.
TASTE FOE TflE BEAUTIFUL.
Ill
^W°*' mid sometimes as a sign of kinship.
S. *le turned a reed-bunting ( Emberiza solioeniculus), aUi|' 1 ^ad acquired its black head, into his aviary, k. ,ttle new-comer was not noticed by any bird, except bnii*!. ^"Utinch, which is likewise black-headed. This lUfii l,lf' was a very quiet bird, and had never before tee'd ',!U0d with al>y o1' its comrades, including another },r.,( ' M||'1ing, which had not as yet become black- a0 * : but the reed-bunting with a black head was \jr ^ercifully treated, that it had to be removed. V;,eir Was also obliged to turn out a robin, as it tnan.e "V attacked all birds with any red in their plu- bj^P’ but no other kinds; it actually killed a red- tbe 8 ':(* c|,ossbill, and nearly killed a goldfinch. On first °- Ire has observed that some birds, when
Hi(:,mtro<lnced into his aviary, fly towards the species
tli, ■ 1 .’Kemble them most in colour, and settle by * sides.
plUu r birds display with so much (tare their fine ib^/md other ornaments in the presence of the tfi,. p °'S’ ^ is obviously probable that these appreciate obtainai% of their suitors. It is, however, difficult to ^'rect evidence of their capacity to appreciate Sfiisa / ^ben birds gaze at themselves in a looking- ° wbich many instances have been recorded) we ft-Jel sure that it is not from jealousy at a sup- though this is not the conclusion of some WV6rs- In other cases it is difficult to distinguish
the
een
fo
ps
mere curiosity and admiration. It is perhaj ^tiact tflei' which, as stated by Lord Lilford,14
s° th f . bluff strongly towards any bright object, “ bri,|i ’ the Ionian Islands, it “will dart down to a
glit-,
coloured handkerchief, regardless of repeated
14 Tlie 1 Ibis,’ vol. ii. 1860, p. 344.
112
SEXUAL SELECTION : BIRDS.
PA*1'
Ml
“ shots.” The common lark is drawn down from 1 sky, and is caught in large numbers, by a small m,r; made to move and glitter in the sun. Is it admin1'1 ' or curiosity which leads the magpie, raven, and s° ^ other birds to steal and secrete bright objects, sud1 silver articles or jewels ?
Mr. Gould states that certain humming-birds de ; rate the outside of their nests, “ with the utmost t»®^ “they instinctively fasten thereon beautiful pie^3.., 1 “ Hat lichen, the larger pieces in the middle, and ;
“ smaller on the part attached to the branch. P j “ and then a pretty feather is intertwined or fasteI* j “ to the outer sides, the stem being always so “ that the feather stands out beyond the surface.” j - best evidence, however, of a taste for the beaut if u; afforded by the three genera of Australian bowef"h>' already mentioned. Their bowers (see fig. 46, [»• 1 . where the sexes congregate and play strange antics,- ' ^ differently constructed, but what most concerns us is> 1 j they are decorated in a different manner by the sef£'j species. The Satin bower-bird collects gaily-cok0’ articles, such as the blue tail-feathers of parrakc' , bleached bones and shells, which it sticks between 1 j twigs, or arranges at the entrance. Mr. Gould f°ll\ in one bower a neatly-worked stone tomahawk al1 . ...
n<
f id*
slip of blue cotton, evidently procured from, a encampment. These objects are continually rearraWrj and carried about by the birds whilst at play-
bower of the Spotted bower-bird “ is beautifully “ with tall grasses, so disposed that the heads “ meet, and the decorations are very profuse.” P®11 stones are used to keep the grass-stems in their pr°jj|f places, and to make divergent paths leading to . bower. The stones and shells are often brought h a great distance. The Eegent bird, as describe^
PREFERENCE BY THE FEMALE.
113
Cn.
,Ap- XlV.
Ra
itr. ^
lajjj \amsay, ornaments its short bower with bleached “ p, s. e^s belonging
0 . ...... B to five or sis species, and with
“ -• l6s °f various colours, blue, red, and black, which
“ ([j e ^ "hen fresh a very pretty appearance. Besides “ y0^e there were several newly-picked leaves and “ m » shoots of a pinkish colour, the whole shewing a Say taste for the beautiful.” Well may Mr. Gould “ je lese highly decorated halls of assembly must be “ te*.ai as the most wonderful instances of bird-archi- tL, t,.Ule y°t discovered;” and the taste, as we see, of
! Se"eral
species certainly differs.15
^\'ifermee for Partieutar Males by the Females. —
)iatj0l ? these preliminary remarks on the discrimi-
t° ^ ail(t taste of birds, I will give all the facts known
for * "Rich bear on the preference shewn by the female
bircj8 "'"lar males. It is certain that distinct species of
^Wid°fai0IlaI1y pair in a state of liature and produce
livtav A,any instances could be given : thus Maegil-
“ f'eii how a male blackbird and female thrush
(j 11 in '
Sral
^6v°ral ^°Ve VV1'^1 eac^ °fhcr,” and produced offspring.16 the o , ' ears ago eighteen cases had been recorded of ^aok CUrience in Great Britain of hybrids between the n»,ly a'°Use and pheasant;17 but most of these cases ^fiiiitr'1 laP8 he accounted for by solitary birds not °tker^.0ne of their own species to pair with. With i'Jbri^11^’ aS ^r‘ J°uiier Weir has reason to believe, fc°arse 0j.dr® sometimes the result of the casual inter- 0 birds building in close proximity. But these
On
the
<j'r‘ to tynamented nests of humming-birds, Gould, ‘ Introdue- l{rlMho0]i: , roetilida3,’ 1861, p. 19. On the bower-birds, Gould n*Say in ,^e ®irds of Australia,’ 1865, vol. i. p. 441-461.
‘ hist, lb!s>’ 18(ih p. 456.
‘2or>i_ . “Utisb Birds,’ vol. ii. p. 92.
114
SEXUAL selection: birds.
FM
remarks do not apply to the many recorded instance® tamed or domestic birds, belonging to distinct sp6^' which have become absolutely fascinated with e4tC. other, although living with their own species. Waterton18 states that out of a flock of twenty-^ j{ Canada geese, a female paired with a solitary Bern’1' . gander, although so different in appearance and and they produced hybrid offspring. A malo W'o ? ( Mareea penelojie), living with females of the -c‘l j, species, has been known to pair with a Pintail Querquedula acuta. Lloyd describes the remark® \ attachment between a shiehl-drake (Tadorna vulpti'11* , ; and a common duck. Many additional instances c°u be given ; and the Rev. E. S. Dixon remarks that “ 1 ^ “ who have kept many different species of gee®e
gether, well know what unaccountable attaching “ they are frequently forming, and that they are 4° 3 “ as likely to pair and rear young with individual® 0 . “ race (species) apparently the most alien to them®e'
“ as with their own stock.” ^jj
The Rev. W. D. Fox informs me that he possess®' ^ the same time a pair of Chinese geese (Anser cygn°u ^ and a common gander with three geese. The two ^ kept quite separate, until the Chinese gander one of the common geese to live with him. More*1' of the young birds hatched from the eggs of the con'1'^ geese, only four were pure, the other eighteen pr0' ,( hybrids ; so that the Chinese gander seems to k®.jj had prepotent charms over the cominoii zander. ^ '
■ ti|f,
" Waterton, ‘Essays on Nat. Hist.’ 2nd series, p. 42, 117. following statements, see on the wigeon, Loudon’s ‘ Mag. of N'at- ‘ pi vol. ix. P- 616; L. Lloyd, * Scandinavian Adventures/ vol. i. 185L Dixon, ‘ Ornamental and Domestic Poultry,’ p. 137 ; Hewitt, in ‘ , of Horticulture,’ Jan. 13, 1S63, p. 40; Beclistein, ‘ Stubcnvdgd,
H. 230.
XIV.
PREFERENCE BY THE FEMALE.
115
u>' one other case ; Mr. Hewitt states that a wild “Sfi J rea,'ed in captivity, “after breeding a couple of “ ori 0118 'v’^1 ^er °wn mallard, at once shook him off “ ev. !°y placing a male Pintail on the water. It was “abn-—?^ a case ot' l°ve at ^'1-st sight* lor she swam
“Jknt]J alarmed and
the new-comer caressingly, though ho appeared
to her overtures of
averse
“ From that hour she forgot her old partner.
“sef.llter Passed by, and the next spring the Pintail 11 jq le<t to have become a convert to her blandish- “ vrJ 8’ ^or they nested and produced seven or eight
%
Vs.
at the charm may have been in these several
Wond
mere novelty, we cannot even conjecture.
i0Ur l
°r<ler / l0wever, sometimes comes into play ; for in
Uii(j .. 0 raise hybrids from the siskin ( Fringilla spinus)
•K b|]A ... 1 ,1 1 i _ ' i..
hybrids from the siskin ( Fringilla spinus) . y, it is much the best plan, according to 3l|. j , |IJ> to place birds of the same tint together. ivheveei-»er Weir turned a female canary into his aviary, grep,* ,tllere were male linnets, goldfinches, siskins,
. Ca-Iln„l , „ . , . , .
loiiU c 1 sbe would choose ; but there never was any and ’ Un<l the greenfinch carried the day. They paired Wi,ifuced tylmd offspring.
* te 'oombers of the same species the fact of the Preferring to pair with one male rather than Het[l lutber is not so likely to excite attention, as l‘aa jj Us occurs between distinct species. Such cases 'Hr], 'Jc observed with domesticated or confined att<l B’ Jll\ these are often pampered by high feeding,
tfriae ^ ^mes have their instincts vitiated to an ex- r°ofs
>ot v' .
^Cniw. e here related. Vitiated instincts may also
^°ree’ Of this latter fact I could give sufficient
'vith
pigeons, and especially with fowls, but they
;°U*t f0r
some of the hybrid unions above referred
116
SEXUAL SELECTION: BIRDS.
Pab1*
J
to ; but in many of these cases the birds were all0"^ to range free ly over large ponds, and there is no i'efis^ to suppose that they were unnaturally stimulated
high feeding.
r
With respect to birds in a state of nature, the and most obvious supposition which will occur to eve’y one is that the female at the proper season accept® first male whom she may encounter; but she ha® ■■ least the opportunity for exerting a choice, as sl>® almost invariably pursued by many males. Audu ^ — and we must remember that he spent a long lde j prowling about the forests of the United States ^ observing the birds — -does not doubt that the feD,£1JI deliberately chooses her mate ; thus, speaking of a pecker, he says the hen is followed by half-a-dozen suitors, who continue performing strange antics, “ 1111 •'
: a marked preference is shewn for one.” The fem
a-l®
the red-winged starling (Ageheus phceniceus) is like^
pursued by several males, “ until, becoming fat'd
“ she alights, receives their addresses, and soon ",;l
&
“ a choice.” He describes also how several male Ob'
A
jars repeatedly plunge through the air with asto"IS ;l
rapidity, suddenly turning, and thus making, , singular noise ; “ but no sooner has the female b* ■'
1 her choice, than the other males are driven a With one of the vultures ( Cathartes aura ) of the L Jil .
States, parties of eight or ten or more males and
assemble on fallen logs, “ exhibiting the strongest
“ to please mutually,” and after many caresses, each 1 * leads off his partner on the wing. Audubon lik^W/
carefully observed the wild flocks of Canada geese (/ j ^
tltf1
Canadensis), and gives a graphic description ot ^
o i i
love-antics ; lie says that the birds which had been f ^ viously mated “ renewed their courtship as early aS ^ “ month of January, while the others would be co"lt
PREFERENCE BY THE FEMALE.
117
Ca.
4P.
Xiv.
Itlrr ,
“ 8 r °r C0(luetting for hours every day, until all seemed ! ? ls®ed with the choice they had made, after which, !ough they remained together, any person could
Perce^Te that they were careful to keep in pairs. ***** observed also that the older the birds, the <1'l’l°lter Were tbe preliminaries of their courtship.
« 9 bachelors and old maids, whether in regret, or ■<m0t cai’hig to be disturbed by the bustle, quietly “ t aside and lay down at some distance from the Wh U Many similar statements with respect to other Coidd be cited from this same observer.
\Viu"luing now to domesticated and confined birds, I spec)-)rnrileilce by giving what little I have learnt re- Wtomg the courtship of fowls. I have received long tnej 011 this subject from Messrs. Hewitt and Teget- j!1’ ai'd almost an essay from the late Mr. Brent. &o 1 : be admitted by every one that these gentlemen, ata] * known from their published works, are careful fenced observers. They do not believe that the tli^, CS Pl'efer certain males on account of the beauty of tJifi Pjuniage; but some allowance must be made for k6ptaitlficial state under which they have' long been tl10)l' kb'. Tegetmeier is convinced that a game-cock, bin & * 'b'^figured by being dubbed with his hackles inj> r ’ Would be accepted as readily as a male retain- bis natural ornaments. Mr. Brent, however, e^if8 t]mt the beauty of the male probably aids in Jlv> ^ S bie female ; and her acquiescence is necessary, left b convinced that the union is by no means
mere chance, for the female almost invariably hei1CgS.*'be most vigorous, defiant, and mettlesome male ; b is almost useless, as he remarks, “ to attempt
"k® ; vol 'b.lin> * Ornitliolog. Biography,’ vol. i. p. 191 , 319 ; vol. ii. P- 12,
118
SEXUAL SELECTION : BIRDS.
PAR* 1
good health and c0iJ
“ true breeding if a game-cock in ^
“ dition runs the locality, for almost every hen on leavi1’^ “ the roosting-place will resort to the game-cock, eV “ though that bird may not actually drive a way the s®1 “ of her own variety.” Under ordinary circumstances , males and females of the fowl seem to come to a W'd11 j understanding by means of certain gestures, descri^f to me by Mr. Brent. But hens will often avoid , officious attentions of young males. Old hens:
si*1
hens of a pugnacious disposition, as the same "'*'
informs me, dislike strange males, and will not until well beaten into compliance. Ferguson, howe' describes how a quarrelsome hen was subdued by * gentle courtship of a Shanghai cock.20 ,
There is reason to believe that pigeons of both se*g,
prefer pairing with birds of the same breed ; and do'
, 21 Jm
cot-pigeons dislike all the highly improved breeds. Harrison Weir has lately heard from a trustwod ■ observer, who keeps blue pigeons, that these dr* away all other coloured varieties, such as white, *’ ^ and yellow ; and from another observer, that a dun carrier could not be matched, after repeated t*'i!l with a black male, but immediately paired with a d**^ Generally colour alone appears to have little infli*eU on the pairing of pigeons. Mr. Tegetmeier, at my 1 quest, stained some of his birds with magenta, but u:t were not much noticed by the others. f
Female pigeons occasionally feel a strong antipftt towards certain males, without any assignable call\. Thus MM. Boitard and Corbid, whose experience tended over forty-five years, state : “ Quand une fe***e
a
■it*
20 ‘ Rare and Prize Poultry,’ 1854, p. 27. , ^
21 ‘Tiro Variation of Animals and Plants under Domesticatin'1’
PREFERENCE BY THE FEMALE.
119
C6.
At.
Xiv
« v r°llVe de l’antipatlue pour un male avec lequel on ^ decoupler, malgre tous les feux de 1 amour, “ ii U I'alpiste et le chenevis dout on la nourrit “ J*'11' augment©!- son ardeur, malgre un emprisonne- « six mois et meme d’un an, elle rel'use con- ses caresses; les avarices empressees, les « r^aceries, les tournoiemens, les tendres roucoulemcns, “ de U IJe Peut dn pl;rii'e ni l’emouvoir ; gonflee, bou- Use> hlottie dans un coin de sa prisou, ello n’en sort '• e P°ur boire et manger, ou pour repousser avec une 0U ^ce rage des caresses devonues trap pressautes.” 22 oljH. le ether band, Mr. Harrison Weir has himself l'err| !.' °d, and has heard from several breeders, that a a 8- 6 pigeon will occasionally take a strong faucy for Ij^^d-ular male, and will desert her own mate lor ok.’ ®01ue females, according to another experienced
liefer
^Ulo;
er= Riedel,23 are of a profligate disposition, and almost any stranger to their own mate. Some 'di'd^8 Ula^e8> called by our English fanciers “gay If,. ’ ate so successful in their gallantries, that, as ‘ JR Weir informs me, they must be shut up, on
aCc ,v oir mtorms me, they must ut ^r.at °f the mischief which they cause.
in the United States, accordin
to
on, “
sometimes pay their addresses to the domes- “ C* Canales, and are generally received by them ptef,-.r ®real pleasure.” So that these females apparently 1R "dd to their own males.24 Ltian- a more curious case. Sir It. Heron during fovviy yeai's
kept an account of the habits of the pea-
" hich he bred
in large numbers.
He states that
au<t Corbie, ‘ Les Pigeons,' 1S24, p, 12. Prosper Lucas 1'Here'd. Nat.’ tom. ii. 1S50, p. 29U) has himself observed 53 fclill'fac*-vith pigeons.
21 ‘Ornim beDzueht'’ 182b »■ 86-
1 hologieai Biography,’ vol. i. p. 13.
120
SEXUAL selection: birds.
PaM
“the hens have frequently great preference to a Pa* “ ticular peacock. They were all so fond of an old p'"
“ cock, that one year, when he was confined thoh-^ “ still in view, they were constantly assembled c'l°; “ to the trel lice- walls of his prison, and would not “ a japanned peacock to touch them. On his being “ out in the autumn, the oldest of the hens install- “courted him, and was successful in her courts^' “ The next year ho was shut up in a stable, and ^ “the hens all courted his rival.”25 This rival 'vaS " japanned or black-winged peacock, which to our is a more beautiful bird than the common kind. ^ Lichtenstein, who was a good observer and excellent opportunities of observation at the Ope 0 Good Hope, assured Eudolphi that the female wid°"j bird ( Chera progne) disowns the male, when robbed the long tail-feathers with which he is ornamd'fo during the breeding-season. I presume that this 0 , serration must have been made on birds under c°'l, fmement.-b Here is another striking case ; Dr. Jaeger'. director of the Zoological Gardens of Vienna, that a male silver-pheasant, who had been triumph1.1* over the other males and was the accepted lover oi t females, had his ornamental plumage spoiled. ^ ^ was then immediately superseded by a rival, who S° the Upper hand and afterwards led the flock.
Not only does the female exert a choice, but in s01'! few cases she courts the male, or even fights for ^ possession. Sir R. Heron states that with peafowl,
25 ‘ Troc. Zool. Son.’ 1S35, p. 51 Tie japanned peacock is sidered by Mr. Selater as a distinct species, and las been «! Pavo nigripemiis.
26 Eudolpiii ■ Beytrage zur Anthropologie,’ 1812, s. 184
27 ‘Die Darwin’sole Theorie, and ilre Stellun- zu Moral Religion,’ 1869, s. 59.
aid
PREFERENCE BY THE FEMALE.
121
Ca.
:4p.
XIV.
adve
thi^^s are always made by the female - °f the same kind
some- accordincr to
AUr]'' . the same kind takes place,
\\’ip4 'i'11’ vvith the older females of the wild turkey. Wbjpt ,'e Capercailzie, the females flit round the male, Uuc| ,.le ts parading at one of the places of assemblage, 1CI^ Itis attention.28 We have seen that a tame fjw. .!lek seduced after a long courtship on unwilling
u
>> lit,
Mr. Bartlett believes that the Lopho-
- many other gallinaceous birds, is naturally • ^anions, but two females cannot be placed in the a male, as they fight so much together,
it rel. r°WluS instance of rivalry is more surprising as j* es to bullfinches, which usually pair for life. ^hUalr n-llei ^ ek' introduced a dull-coloured and ugly attotb aviary, and she immediately attacked
kad |Q tinted female so unmercifully that the latter shiv. )0 separated. The new female did all the court-
4 -1"'1
for
e . j "as at last successful, for she paired with the after a time she met with a just retribution,
°lcl /, as'ng to be pugnacious, Mr. Weir replaced the
h;t„ ',n“
male
In
to his
and the male then deserted his new and
ftee«pt ■ °rdiuaiT eases the male is so eager that lie will tkefei, U,l-V female, and does not, as far as we can judge, 'Vo sb.jj16 f° the other ; but exceptions to this rule, as Rafter see, apparently occur in some few
old lov
;e.
°ae |.a‘ ^ iff1 domesticated birds, I have heard of only
111 "dl'ck the males shew any preference for "ho, a / females, namely, that of the domestic cock, IX, to the high authority of Mr. Hewitt,
e younger to the older hens. On the other
% It)
l'or k aU(l tH^ i° Pcaf'owt see Sir E. Heron, ‘ Proo. Zoolog. Soc.’ 1835, thirl-6 ^CV‘ ^xonj ‘Ornamental Poultry,* 1848, p. 8.
ftiivi^0?’ ^utlubon, ibid. p. 4. For the capercailzie, Lloyd,
8 °f Sweden/ •,cw‘~
18(37, p. 23.
122
sexual selection: birds.
Pi*'
J
hand, in effecting hybrid unions between the & J pheasant and common hens, Mr. Hewitt is convi^^, that the pheasant invariably prefers the older l'ir^ He does not appear to be in the least influence" ^ their colour, but “ is most “ capricious in his ments.” 29 From some inexplicable cause he shews . I
8<*
most determined aversion to certain hens, which care on the part of the breeder can overcome, hens, as Mr. Hewitt informs me, are cpiite unatti'F even to the males of their own species, so that may bo kept with several cocks during a whole
$
/
son, and not one egg out of forty or fifty will F; vl
fertile. On the other baud with the Long-tailed 11 ;
(. Marelda glacialis), “it has been remarked, s" M. Ekstrom, “that certain females are much “courted than the rest. Frequently, indeed, o»e “ an individual surrounded by six or eight “males.” Whether this statement is credible, I not; but the native sportsmen shoot these feimd6 order to stuff them as decoys.30 d I
With respect to female birds feeling a pref'eret^1’ ^
particular males, we must bear in mind that v'e judge of choice being exerted, only by placin;
o'11
selves in imagination in the samo position. * inhabitant of another planet were to behold a j of young rustics at a fair, courting and quart6 M over a pretty girl, like birds at one of their ph10* I assemblage, he would be able to infer that she h3L | power of choice only by observing the eagerness 0 ^ wooers to please her, and to display their finery- 'yf with birds, the evidence stands thus ; they have powers of observation, and they seem to have b
-9 Mr. Hewitt, quoted in ‘ Tegetmcier’s Poultry Book,’ 18fiC’ 30 Quoted in Lloyd’s 1 Game Birds of Sweden,’ p. 345.
JF,
P-
PREFERENCE BY THE FEMALE.
123
VXlv.
Ste
is c °y the beautiful botli in colour and sound. It iiq]. ain that the females occasionally exhibit, from 6W,0'Jn Cause"S the strongest antipathies and prefer-
es i c°loUl.
' IOr particular males. When the sexes differ in
Ceptj °r m other ornaments, the males with rare ex- Hetltpns av° the most highly decorated, either perma-
0l' temporarily during the breeding-season. They <*y display their various ornaments, exert their fetuaj5’ perform strange antics in the presence of the
he, Gs 171 1 ' 1
-j6J) Even well-armed males, who, it might have longht, would have altogether depended for otlla;;s (>ri the law of battle, are in most cases highly t^etlhed; and their ornaments have been acquired exPense of some loss of power. In other cases fflc f)''nts have been acquired, at the cost of increased cios 0111 birds and beasts of prey. With various spe- any individuals of both sexes congregate at the P°b and their courtship is a prolonged affair. ls even reason to suspect that the males and 1 Within the same district do not always succeed
'Pie,
%h!Sl"g Gaeh other and pairi
tker‘ are we to conclude from these facts and !0%o'ation8? Does the male parade his charms with 'ls,ifu:;,|l I"1111? and rivalry for no purpose? Are we not HHrJ ^ 111 believing that the female exerts a choice, sbo receives the addresses of the male who Seio^e] ler most ? It is not probable that she con- liberates; but she is most excited or at- ant tbe most beautiful, or melodious, or gal-
uur.
Hesales; ^°r nged it be supposed that the female
A ~ -j- - - -- j - x
Q p6ac Ce> admires each detail in the gorgeous train of
^ ^a<k sti'ipe or spot of colour; that the peahen,
Hi
C°ck~
Ee
Ar;
-she is probably struck only by the general °Yertl)eless after hearing how carefully the §as pheasant displays his elegant primary
124
SEXUAL SELECTION: BIRDS.
PAS1"
0
«w
wing-feathers, and erects his ocellated plumes in right position for their full effect ; or again, ho"' male goldfinch alternately displays his gold-bespat®*^ wings, we ought not to feel too sure that the h’11^, does not attend to each detail of beauty. We l
• i i i i i pi- , • ,.,-erw
judge, as already remarked, of choice being es01 only from the analogy of our own minds ; and
mental powers of birds, if reason be excluded, <1° . considerations we may conclude that the pair111
I
birds is not left to chance ; hut that those males, "^ft are best able by their various charms to please or eSf. the female, are under ordinary circumstances accsf If this be admitted, there is not much difficult) fl| understanding how male birds have gradually acfi’j jr I their ornamental characters. All animals present "h. vidual differences, and as man can modify his don;l^, cated birds by selecting the individuals which &l’^,,r to him the most, beautiful, so the habitual or even 0 sional preference by the female of the more attrs1
i"
:ajL
males would almost certainly lead to their modificaI*' p and such modifications might iu the course of tife ^ augmented to almost any extent, compatible wi^1 existence of the species.
Variability of Birds, and especially of their seco,u ^ , Sexual Characters. — Variability and inheritance 9,16 f foundations for the work of selection. That doP1'.,^ cated birds have varied greatly, their variations inherited, is certain. That birds in a state of n*1^ present individual differences is admitted by e\ $ one ; and that they have sometimes been modifi01 ^ distinct races, is generally admitted.31 Variation5
the!® 6i
81 According to Dr. Blasius (< Ibis,’ vol. ii. I860, p. 297), 425 indubitable species of birds which breed in Europe, beSl
VARIABILITY.
125
<b.
Ap.
Xiv.
°f two ].-
wliich insensibly graduate into each other, the s • ’ sh’ght differences between all the members of ll(J species, and more strongly-marked deviations 'vitli r .°Ccur °fly occasionally. These latter are rare
^len transmitted to succeeding generations.3 c!tae8 lr’^essj it may be worth while to give the few ^el<l!lj1°'a1l’T? chiefly to colour (simple albinism and
ljifcls ia a state of nature, and it is very doubtful ei they have often been preserved through selec-
c°llf.etSm ^eing excluded), which I have been able to
of y is well known rarely to admit the existence
8p6ejglttleSj for he esteems very slight differences as ^ Il0v'r he states 33 that near Bogota certain hum- !Wifje;jll.^s belonging to the genus Cynanthus are ftOm lnto two or three races or varieties, which differ c 1 other in the colouring of the tail, — “ some
6
S, ttM are ftoquently regarded a3 distinct species. Of the latter, tia to be , vs that only ten ore really doubtful, and that the other fifty be a a llnjted with their nearest allies ; hut this shews that there Iff*8' It •0n®<t°rat>le amount of variation with some of our European Au,eS R*so an unsettled point with naturalists, whether several 'a2<**»espoa)yn ^‘rt's ought to be ranked as specifically distinct from
^ _ ]
| * 1 - C!iiic.fj riU l an|I strongly-marked deviations of structure, deserving ,v;<jtion, an??i1Stl'l,s®es’ ouuld seldom be preserved through, natural cin| depeuV ”at *'10 preservation of even highly-bendioial variations ta the; in a certain extent on chance. I had also fully appre- o 'Pounce of mere individual differences, and this led i
‘Orj,,.: ll,lS European species.
C(I, duit" 01 ®l-iei'*t!si' fifth edit, 18011, p. 104. I had always per*
vj<; ^ strongly on the importance of that unconscious form of 0-!l) iH(HVjijUatl’ which follows from the preservation of the most th. V th<, „i Uu*8 each breed, without any intention on his part to l*.,'/ korti, na^clra8 °I the breed. But until I read an able article in (March, 1867, p. 2S9, el seq.), which has
of ia Review
^ Use to me than any other Review, I did not see how
33 , 0t stro n°iaS "ere aSaiust the preservation of variations, whether * I niton. ^ y pronounced, occurring only in single individuals.
Uct- to the Trochilida;,' p. 102.
126
SEXUAL selection: birds.
“ having the whole of
the feathers blue, while
oth^!
“ have the eiglit central ones tipped with bea'1
tit'"
green, dations have
It does not appear that intermediate een observed in this or the foil** In the males alone of one of the Austr1'1 parrakeets “the thighs in some are scarlet, in ot )( “ grass-green.” In another parrakeet of the ^
cases.
country “some
individuals have the band across
“ wing-coverts bright-yellow, while in others the s* , “part is tinged with red.”34 In the United
some few of the males of the Scarlet Tanager ( Tan
of
rubra) have “a beautiful transverse band of gl°".
in?
“red on the smaller wing-coverts ;”35 but this vai'i^!.
pV3t"
preserv^!
#1
seems to be somewhat rare, so that its through sexual selection would follow only unusually favourable circumstances. In Bengal Honey buzzard (Pernis cristata) has either a £ * ^ ' slig11*
Off
rudimental crest on its head, or none at all ; so difference however would not have been worth i
had not this same species possessed in Southern
crest formed of several
“a well-marked occi
“ duated feathers.” 36 A
The following case is in some respects more intel'i|, ing. A pied variety of the raven, with the head, j abdomen, and parts of the wings and tail-feathers " ^
is confined to the Feroe Islands. It is not v®r) i |,
rr
erv 1 *,
there, for Graba saw ten living specimens.
during his visit from eig
fit
of 1 i
Although the characters - m
variety are not quite constant, yet it has been
distinguished ornithologists as a J
1
by several distinguished ornithologists as a species. The fact of the pied birds being pursue0
A156'
M Gould, ‘ Handbook of Birds of Australia,’ vol. ii. p. 32 au( Audubon, ‘ Omitbolog. Biography,' 1838, vol. iv. p. 389. _ 3f' Jordon, ‘ Birds of India.,’ vol. i. p. 108 : and Mr. Blyth, and Water,' 1868, p. 381.
VARIABILITY.
127
J‘UP.
Xiv.
P^Secnf l .
the ; i C6Cl W1^ much clamour by the other ravens of Cot>e] Was ^le ohfof cause which led Briinnich to ti0\v e ^'a* it was specifically distinct; but this is In v°l-n t0 be an error.37
v^^ous parts of the northern seas a remarkable
ftficl ; ' ^ tbe common Guillemot ( Uria troile) is found; - ui pe
Qtaljr‘ Cer°e, one out of every five birds, according to ll''f,dJs jjy a pUre -wBite ring round the eye, with
raet,
l>ed
s estimation, consists of this variety. It is elm-
narrow white line, an inch and a half in % ej’ ^tending back from the ring. This conspicu- S|'vti'‘i) Uac^ei' bas caused the bird to be ranked by Hp 0rTlitliologists as a distinct species under the ^ vUl.- ' luerymans, but it is now known to be merely It often pairs with the common kind, yet fills s f la^e gradations have never been seen; nor is for variations which appear suddenly -ifiipj, en> as I have elsewhere shewn,39 transmitted S«2fred. or not at all. We thus see that two a- °!'ms of the same species may co-exist in the PosSe s nct, and we cannot doubt that if the one had any great advantage over the oilier, it would ^ f0r ave been multiplied to the exclusion of the latter. ln8taBce, the male pied ravens, instead of being ' 1 and driven away by their comrades, had ^tii/"’ ^ attractive, like the pied peacock before hJii]([ p c > f° the common black females, their numbers Jeea a ave rapidly increased. And this would have Case °f sexual selection.
W h * Hie* aSetmch, Tieisc nach Faro,'
'!■ Britisli It;,.. I , > .,,.1 „ -7,1
1830, s. 51-54. Macgil- 745. ‘ Ibis,’ vol. v. 1863, p.
British Birds,’ vol. iii. p,
t. go y^riatio^' S’ ^ac&Blivray, ibid. vol. v. p. 327.
Of A TUmolo And T)l-,ntA nndAM l l/i m aaXi/1
°f Animals and Plants under Domestication,’ vol. ii.
SEXUAL SELECTION : BIEDS.
1118
px®*1
1 it!
With respect to the slight individual differences ^ ■ are common, in a greater or less degree, to ah
members of the same species, we have every to believe that they are by far the most imp0' ^ for the work of selection. Secondary sexual char® , 4 are eminently liable to vary, both with animals state of nature and under domestication.40 The1® also reason to believe, as we have seen in our
in 1
chapter, that variations are more apt to occur - je,
male than in the female sex. All these continge°, ,f
are
highly favourable for sexual selection. W
7b#
characters thus acquired are transmitted to cue . or to both sexes, depends exclusively in most c9 ^
as I hope to shew in the following chapter,
on
form of inheritance which prevails in the group®
if
question. ^
It is sometimes difficult to form any opinion wbe jj
l
certain slight differences between the sexes of ^
are simply the result of variability with seX
.viu1
Hf
limited inheritance, without the aid of sexual se
or whether they have been augmented through ^ latter process. I do not here refer to the innuine19 instances in which the male displays splendid 0 u
Ofl1'
or other ornaments, of which the female partake® . a
to a slight degree; for these cases are almost cei'tilh.
due to characters primarily acquired by the
having been transferred, in a greater or less degff^i the female. But what are we to conclude with red1 ,,f to certain birds in which, for instance, the eyes ' 1 jt;
slightly in colour in the two sexes?41 In some ^
the eyes differ conspicuously; thus with the
stor*
¥
■ii1 On these points see also ‘Variation of Animals and Plants Domestication,’ vol, i. p. 253 ; vol. ii. p. 73, 75. , fF
41 See, for instance, on the irides of a Podica and GallicreX in vol. ii. I860, p. 206 ; and vol. v. 1863, d. 426.
VARIABILITY.
129
Ar>
XIV.
Of
the
are
blacv- Senus Xenorhynchus those of the male a t- s 'Wei, whilst those of the females are gam-
^e-yello
om ir > with many hornhills (lluceros), as I hear
(L. ^ B]v+R 42
hi!/wies
'W;
Ulvtli,4- the males have intense crimson, and white eyes. In the Buceros bicornis, the
Afg a* are black in the male, but not so in the female.
e be.^ 5111 ^ie (Jasclue an(t a stripe on the crest of
'bin
ti6;
*e to Sou
!1Jted
V0|'V
suppose that these black marks and the c°lour of the eyes have been preserved or aug- H, through sexual selection in the males? This ^0q1o,‘. c °ubtful ; for Mr. Bartlett shewed me in the ^Ucer&lCa^ hardens that the inside of the mouth of this ^hale. JS 'back in the male and flesh-coloured in the tot be’!ln<* their external appearance or beauty would *bfj ; IUs affected. I observed in Chili43 that the
^the
<4,„
K
kt
condor, when about a year old, is dark-brown,
ail&es maturity into yellowisli-brown in the
The male
]l*ts a]atlc' »>to bright red in the female.
''%t ( a sniall, longitudinal, leaden-coloured, fleshy "Wb is .c,°mb. With many gallinaceous birds the ''tritg ^|uSbly ornameutal, and assumes vivid colours 'b thg 1 ® aut of courtship ; but what are we to think 1|()t 1:1 ^-coloured comb of the condor, which does
K
appear
:stio
t° us in the least ornamental? The same
lnay be asked in regard to various other l*e Objp SUc'J as the knob on the base of the beak of Wr jQeSe S°Qse (. Anser cygnnides), which is much aWer c the male than in the female. No certain If ^ ^'ven to these questions; but we ought
®8hy a 1Qus in assuming that knobs and various " lc‘ti ^ bondages cannot be attractive to the female, lemember that with savage races of man
130
sexual selection: birds.
p.if
various hideous deformities — deep scars on
the
&
with the flesh raised into protuberances, the of the nose pierced by sticks or bones, holes in th® , |V.
the f
-are all adroit
and lips stretched widely open ornamental. tt’
Whether or not unimportant differences betw®®1’ V,J sexes, such as those just specified, have been pre“ j r
through sexual selection, these differences, as "'L >
0 .... .. . C iTlV
all others, must primarily depend on the laws of tion. On the principle of correlated development’ ' $
plumage often varies on different parts of the jf
body-
I n . A V
over the whole body, in the same manner. " Ji)
this well illustrated in certain breeds of the «l
all the breeds the feathers on the neck and
the males are elongated, and are called hackles , j
when both sexes acquire a top-knot, which is ! (]f
character in the genus, the feathers on the
head
„ ■
male become hackle-shaped, evidently on the prI; J of correlation ; whilst those on the head of the >l, ^ are of the ordinary shape. The colour also 0 ^
hackles forming the top-knot of the male, is oi'ff1!
related with that of the hackles on the neck auo
a K
as may be seen by comparing these feathers 111 ^
Golden and Silver-spangled Polish, the Houduri’
Creve-coeur breeds. In some natural species "e -f
colc^'jl
observe exactly the same correlation in the these same feathers, as in the males of the SP Golden and Amherst pheasants. ^
The structure of each individual feather
causes any change in its colouring to be sym'||(J
we see this in the various laced, spangled,
aud * (i
cilled breeds of the fowl ; and on the prim'd ^
correlation the feathers over the whole body
modified in the same manner. We are thus
eilil
vithout much trouble to rear breeds with then
r
VARIABILITY.
131
V
XIV.
age
.Marked and coloured almost as symmetrically
the0 ftural species. In laced and spangled fowls dfeft0|°Ured margins of the feathers are abruptly
but in a mongrel raised by me from a black l)r;iJ P c°ck glossed with green and a white game to*;," ^he leathers were greenish -black, excepting bm their extremities, which were yellowish-white ; biiSes pvveen the white extremities and the black
Vof
tlllls „a.Per determines the distribution of the tints;
tj'ere was on each feather a symmetrical, curved
dark-bra
% .^w-orown
In some instances the shaft ot
-Unl0 )'th the body-feathers of a mongrel from the , ;lck Spanish cock and a silver-spaugled Polish shaft, together with a narrow space on each greenish-black, and this was surrounded by zone of dark-brown, edged with brownisli- / these cases we see feathers becoming sym-
the
fois
klaj
ifo.
*h!
shaded, like those which give so much Ve rCf to the plumage of many natural species, I H .p° noticed a variety of the common pigeon fright i 'v‘ug-bars symmetrically zoned with three bluy lades, instead of being simply black on a siaty-
as in the parent-species, kt th ,dn^ barge groups of birds it ^
•VH tint b'bumage is differently coloured iu each species,
large groups of birds it may he observed
"ho cj.g, certain spots, marks, or stripes, though like-
'^■Tfoloo- eiently coloured, are retained by all the species.
'hep0118 cases occur with the breeds of the pigeon,
’"ay ^ dually retain the two wing-bars, though they
'pt of loured red, vellow, white, black, or blue, the '
is
plumage being of some wholly different tint, fot- • 1Qore curious case, iu which certain marks lf-VeCsed1U°dl though coloured in almost an exactly .Gunner to what is natural; the aboriginal ds u blue tail, with the terminal halves of the
K 2
132
SEXUAL SELECTION : BIRDS.
fit1
outer webs of the two outer tail-feathers white . ^ there is a sub-variety having a white instead of ^ tail, with precisely that small part black which is ' in the parent-species.44
Formation and variability of the Ocelli or eH ^ ^ Spots on the Plumage of Birds. — As no ornamec^. .,.
more beautiful than the ocelli ontlie feathers of ' ‘‘ g.
- on 1
■■br
birds, on the hairy coats of some mammals, scales of reptiles and fishes, on the skin of amph1
on the wings of many Lepidoptera and other i j- they deserve to be especially noticed. An ocelhi8^],,' sists of a spot within a ring of another colour
like
pupil within the iris, but the central spot is
JbM
rounded by additional concentric zones. The °cC^,lo the tail-coverts of the peacock offer a familiar eX!l' as well as those on the wings of the peacock-but ^ (Vanessa). Mr. Trimen has given me a descrip11 / a S. African moth ( Gynanisa Isi.s), allied to our EUT moth, in which a magnificent ocellus occupies ue!)1 ^ whole surface of each hinder wing ; it consists of centre, including a semi-transparent crescent-* mark, surrounded by successive ochre-yellow, y. ochre-yellow, pink, white, pink, brown, and whitish * ^ Although we do not know the steps by which ^ wonderfully-beautiful and complex ornaments ha'^l; developed, the process at least with insects has pJ° ]J)t' been a simple one ; for, as Mr. Trimen writes
s to
“ no characters of mere marking or coloration ^
“ unstable in tlie Lepidoptera as the ocelli? h° ^ “ number and size.” Mr. Wallace, ’ " ' ""1 L
who first calk .j-
attention to this subject, shewed me a series
of *
mens of our common meadow-brown butterfly
44 Bechstein. ‘ Nnturgpsehichte Deutsclilands,’ B. iv. 1”3J a suk-vuriety of the Monck pigeon.
(W
„ 8t'
OCELLI.
133
Xiv.
a . la Janira ) exhibiting numerous gradations from minute black spot to an elegantly-shaded Wj0i'ls: In a S. African butterfly ( Gytto Leda, Linn.) H0r to the same family, the ocelli are even still Bpae 'il|'iable. In some specimens (A, fig. 52) large 'J!;ir.|-S 011 upper surface of the wings arc coloured tftjs and include irregular white marks ; and from -bite a complete gradation can be traced into a
A Al
CyUo U',iaj jj
inn., from a drawing by Mr. Trimen, shewing the extreme range of variation in the ocelli.
B. Specimen, from Java, upper surface of hind-wing.
B1. Specimen, from Mauritius, ditto.
h. 5^
Sp,*,
4>. n,s»rracl ,m Mauritius, upper Peci®en
ftom Natal, ditto.
Cobti'afJ. ^ Perfect, (A1) ocellus, and this results from the >tW,0» of the irregular blotclies of colour. In fi'0in Sp-ries of specimens a gradation can be followed 'Cess've]y minute white dots, surrounded by a 'V/ ,Visible black line (B), into perfectly symme- bu'ge ocelli (B1).45 In cases like these, the
u* h' Nt
J-hig .
b has been engraved from a beautiful drawing, most
e for me by Mr. Trimen : see also bis description of the
134
SEXUAL SELECTION : BIRDS.
p &
development of a perfect ocellus does not req
uiw
long course of variation and selection.
f#
With birds and many other animals it sceins, ^
the comparison of allied species, to follow, th<1^ ^
cular spots are often generated by the breakup, and contraction of stripes. In the Tragopan pk^k.vi faint white lines in the female represent the bea® ^ white spots in the male ;
and something ^ same kind may be observed in the two sexes 0 6; Argus pheasant. However this may be, appe®1’’^ strongly favour the belief that, on the one hand, 11
spot is often formed by the colouring-matter drawn towards a central point from a surro®®1 ^ zone, which is thus rendered lighter. And, on the *
hand, that a white spot is often formed by the ,ir
7 ---------- x „ . , • i ( ' '
being driven away from a central point, so that n ^ mulates in a surrounding darker zone. In eith*3^ an ocellus is the result. The colouring matter ^,j, to be a nearly constant quantity, but is redfeto tii either centripetally or centrifugaUy. The fea^.jjjt1' the common guinea-fowl offer a good instance 1,1 $
spots surrounded by darker zones; and where'1® (!i white spots are large and stand near each othe®’^ surrounding dark zones become confluent. In the wing-feather of the Argus pheasant dark sp°ts be seen surrounded by a pale zone, and whit'-1 ||lF
o re
by a dark zone. Thus the formation of an “ ^jj By what further steps the more complex ocelli- '
in its simplest state appears to be a simple
wonderful amount of variation in the coloration and shape
of this butterfly, in his ‘Rhopalocera Africse Australis,’ P-
J
ofl<:
also an interesting paper by the Rev. H. H. Higgins, on 1
of the ocelli in the Lepidoptera in the ‘Quarterly Journal July, 1808, p. 825.
«• Jerdon, ‘Birds of India,’ vol. iii. p, 517.
GRADATION OF CHARACTERS.
135
’Ul‘' SIV.
9,1'g
ka SUrr°unded by many successive zones of colour, beae lje<m generated, I will not pretend to say. But ofc/11^ i'1 mind the zoned feathers of the mongrel ot(j!lrinS from differently-coloured fowls, and the extra- t]1(1 ^iry Variability of the ocelli in many Lepidoptera, ljfe „ Ration of these beautiful ornaments can hardly snili _ %hly complex process, and probably depends on tissUes U and g.ra(juated change in the nature of the
n
of , of Secondary Sexual Characters. Cases
it Nation are important for us, as they shew that
^ ^ast possible that highly complex ornaments hi ,llVe been acquired by small successive steps. iyi^i lf to discover the actual steps by which the eo«t °f aUy existiug bird has acquired his magnifi- ^ c°l°Urs or other ornaments, we ought to behold Wt boo of his ancient and extinct progenitors; gene, i is obviously impossible. We may, however, u Sain a clue by comparing all the species of
if it be a large one ; for some of them will their c y vetHilb at least in a partial manner, traces of fletai] °riDer characters. Instead of entering on tedious in^1 S respecting various groups, in which striking Man UOeS °f gradation could be given, it seems the best, casc.s t0 take some one or two strongly-characterised c^’ ,01’ instance that of the peacock, in order to dis- "bicl a.ny light can thus be thrown on the steps by b’ke 1 bir l has become so splendidly decorated. otcli beacoek is chiefly remarkable from the extra- lei^'y length of his tail-coverts; the tail itsell not "'hof ^Ucl1 el°ngated. The barbs along nearly the c]6(.0° length of these feathers stand separate or are of i^r'b°sod ; but this is the case with the feathers U"y species, and with some varieties of the
130
sexual selection: birds.
domestic fowl and pigeon. The barbs coalesce ^ the extremity of the shaft to form the oval disc , ocellus, which is certainly one of the most bca«fI objects in the world. This consists of an irideS^ , intensely blue, indented centre, surrounded by a rl green zone, and this by a broad coppery-brown 0°" t and this by five other narrow zones of slightly-diffcl'e iridescent shades. A trifling character in the disc haps deserves notice the barbs, for a space along ^ of the concentric zones are destitute, to a greater , loss degree, of their barbules, so that a part of the is surrounded by an almost transparent zone, "h1^
gives to it a highly-finished aspect But I have ^
where described47 an exactly analogous variation h‘ ^ hackles of a sub-variety of the game-cock, in the tips, having a metallic lustre, -‘are separated ^
“ the lower part of the feather by a symmetric®^, “ shaped transparent zone, composed of the naked f { “ t!°ns ol the barbs.” The low er margin or hage i
>0^
t!ie dark-blue centre of the ocellus is deeply hide1* on the line of the shaft. The surrounding zones ly 'f wise shew traces, as may be seen in the dra"1'1^ (fig. S3), of indentations, or rather breaks. These ^ dentations are common to the Indian and Javan l1' j cocks ( I’avo cristatus and P. muticus) ; and they to me to deserve particular attention, as probably | ;1 nected with the development of the ocellus; hut long time I could not conjecture their meaning. $ It we admit the principle of gradual evolution, _ must formerly have existed many species which P' seated every successive step between the wonder*'11 ' j, elongated tail-coverts of the peacock and the short &
47 ‘Variation of Animals and Plants under Domestication p. 254.
» fOl’ l’
GRADATION' OF CHARACTERS.
137
Wp.
XIV.
e°vert
tafu> ® °1 all ordinary birds ; and again between the or t 1 eent ocelli of the former, and the simpler ocelli all pi'1'0 c°loured spots of other birds ; and so with to |^e °lher characters of the peacock. Let us look foils ' Gallinacete for any still-existing grada-
-Ihe species and sub-species of Polyplectron
°f ^cock, about two-thirds of natural size, carefully drawn by Mr. C uPper ” 'ansParent zone is represented by the outermost white zone, confined to ihl ena of the disc.
^abit
N^®0^*** adjacent to the native land of the ?re 80l^ ! ail(l they so far resemble this bird that they lf^0,'tn(:,'i^lnes calL'd peacock-pheasants. I am also c°cl; ^ c Ly Mr. Bartlett that they resemble the pea- leh voice and in some of their habits. During
138
SEXUAL SELECTION : BIRDS.
rAf-'f
ifllt
the spring the males, as previously described,
about before the comparatively plain-coloured ^
expanding and erecting their tail and wing-teat ^
which are ornamented with numerous ocelli. I reCl^
the reader to turn back to the drawing (fig. 51, V;
of a Polyplectron. In P. Napoleonis the ocelh
confined to the tail, and the back is of a rich ,
aw
*4
tallic blue, in which respects this species appi'°lU
Java peacock. P. Emrdwiekii possesses a
several species of Polyplectron are either cilC\
the
liar top-knot, somewhat like that of this same of peacock. The ocelli on the wungs and tail ft f
">
or oval, and consist of a beautiful, iridescent, gi'ee jf blue or greenish-purple disc, with a black l'°l This border in P. chinquis shades into brown " is edged with cream-colour, so that the ocell1'^., here surrounded with differently, though not brig ^ shaded concentric zones. The unusual length 0 a tail-coverts is another highly remarkable in Polyplectron; for in some of the species ti*6- $ half as loner, and in others two-thirds of the of the true tail-feathers. The tail-coverts are lated, as in the peacock. Thus the several of Polyplectron manifestly make a graduated , proach in the length of their tail-coverts, in the z<jl ^j,? of the ocelli, and in some other characters, t0 peacock. . (it
Notwithstanding this approach, the first sp^1 Polyplectron which 1 happened to examine almost' ^ me give up the search ; for I found not only th’1 ^jjif true tail-feathers, which in the peacock are quite P ' g were ornamented with ocelli, but that the oce i» all the feathers differed fundamentally from th0"^ the peacock, in there being two on the same 1 (fig. 54), one on each side of the shaft. ffeV
GRADATION OF CHARACTERS.
139
Co.
•VP.
XIV.
Eluded
c , that the early progenitors of the peacock
a, / n°t have resembled in P ' degree a Polyplectron.
lit O" v
1 '/JI1 continuing my search, the Sei’Ved that in some of ,sPecies the two ocelli that Very near each other;
111 the tail-feathers of (;;i! , ardtvic]cii they touched ipy °^lei"> and, finally, that 8pe !e bdl-co veils of this same O* as well as of P. ma- ftctjp (% 55) they were cepta -v confluent. As the
aU ; * ] hai't alone is confluent, the n station is left at both ^’jPper and lower ends; ?0p e surrounding coloured 4 . are likewise indented.
tofr^1^6 ocellus is thus thorn 011 eac^ tail-covert, its k 1 8tiU plainly betraying flu^^hle origin. These cou-
Fig. 54, Part of a tail -covert of Poly- plectron chinquis, with the two ocelli of nat. size.
°celli differ from the
in ~]J ocelli of the peacock an indentation at V/^s, instead of at the 01 ^asal end alone. The 'liffL.aritlt'ou> however, of this *s not difficult ; in
the sPecies of Polyplectron Sajpe w° °val ocelli on the
to ea , ”"ul »umu parallel c°Uv* °t^ei' j in other species (as in P. cldnquis) they tw‘ge towards one end ; now the partial confluence 0 convergent ocelli would manifestly leave a much
aer stand parallel
Fig. 55. Part of a tail-covert of Poly- plectron maluecense, with tilt* two ocelli, partially confluent, of nat. size.
140
SEXUAL SELECTION : BIKDS.
par11
deeper indentation at the divergent than at the
coP'
vergent end. It is also manifest that if the conver
rtreflO®
let*
V
were strongly pronounced and the confluence coinp: the indentation at the convergent end would tend to quite obliterated.
The tail-feathers in both species of peacock at® ‘'j
tirely destitute of ocelli, and this apparently is rek^
to their being covered up and concealed by the 1° *
tail-coverts. In this respect they differ remarkably ^
the tail-feathers of Pol vplectron, which in most of ^
species are ornamented with larger ocelli than those- 6
the tail-coverts. Hence I was led carefully to exam11'
the tail-feathers of the several species of Polyplef'tr (
iii order to discover whether the ocelli in any of oJ<? >
shewed any tendency to disappear, and, to mv gie .
satisfaction, I was successful. The central tail-feat^’'
of P. Najtoleonis have the two ocelli on each side oi
shaft perfectly developed ; but the inner ocellus be<5oI°?,
less and less conspicuous ou the more exterior ^
feathers, until a mere shadow or rudimentary vestig6
left on the inner side of the outermost feather. Ag1*'
A
i0^
in P. malaceense , the ocelli on the tail-coverts arc, a® have seen, confluent ; and these feathers are of uu"b, length, being two-thirds of the length of the ta
\W
thers, so that in both these respects they resemble ^ tail-coverts of the peacock. Now in this species th® ^ central tail-feathers alone are ornamented, each with
brightly-coloured ocelli, the ocelli havii
vmg comple*e.j, disappeared from the inner sides of all the other ^ feathers. Consequently the tail-coverts and tail-feat1'^ of this species of Polyplectron make a near appr°a<g in structure and ornamentation to the correspond feathers of the peacock. *
As far, then, as the principle of gradation thr°'J light on the steps by which the magnificent train the peacock has been acquired, hardly anything lllL'
GRADATION OF CHARACTERS.
141
C14
4p.
XIV.
of ^e^ed. "We may picture to ourselves a progenitor ^tiov Peacofik in an almost exactly intermediate con- between the existing peacock, with his enor- OceHj " elongated tail-coverts, ornamented with single
tail,.
and eoverts
au ordinary gallinaceous bird with short merely spotted with somo colour; and we
•hall +h
tail. n leQ see in our mind’s eye, a bird possessing
'no:
'c° verts hted
capable of erection and expansion, orna-
,<u ( "ith two partially continent ocelli, and long li{lyw 1 ahnost to conceal the tail-feathers.— the latter see w* trendy partially lost their ocelli ; we shall <**Wt, a Polyplectron. Tiie indentation of the spg(1- msc and surrounding zones of the ocellus in both fuV(As °t peacock, seems to me to speak plainly in [>lic„il,ot ^is view; and this structure is otherwise inex-
CJ1.6- The 3
C ul
The males of Polyplectron are no doubt very but their beauty, when viewed from a
“ ^°°logical Gardens, with that of the peacock ‘ ^ale progenitors of the peacock must, during for tp 1110 descent, have appreciated this superiority ;
have unconsciously, by the continued prefer* file ]y. tb° most beautiful males, rendered the peacock °st splendid of living birds.
Ar
gati0^Mf &leasant. — Another excellent case for investi- ng ls °Tsred by the ocelli on the wing-feathers of ^hne S Pheasant, which are shaded in so wonderful a 'vbich as resemble balls lying within sockets, and -I Pres,ie^a8eTuentl y differ from ordinary ocelli. No one,
which has excited
distance.
cannot be compared, as I formerly saw
n© rn.e! "ill attribute the shadin^
Mo ti. llati°u of many experienced artists, to chance
h'° fortuitous concourse of atoms of colouring
„rir, rn
“•OIRA "
, the
fatter. Ti ;;
lnat these ornaments should have been formed
tl
16 selection of many successive variations, not "kick was originally intended to produce the
142
sexual selection: birds.
ParI1
0$
w
ball-and-socket effect, seems as inci’edible, as that of Raphael’s Madonnas should have been formed the selection of chance daubs of paint made long succession of young artists, not one of whom tended at first to draw the human figure. In ord® discover how the ocelli have been developed, we 6
ctiV
not look to a long line of progenitors, nor to vai'* closely-allied forms, for such do not now exist.
ciif
put
fortunately the several feathers on the wing 3iy) to give us a clue to the problem, and they pro'6 demonstration that a gradation is at least possible & a mere spot to a finished ball-and-socket ocellus.
The wing-feathers, bearing the ocelli, are covered v dark stripes or rows of dark spots, each stripe or 1 ^ running obliquely down the outer side of the shaft ,, an ocellus. The spots are generally elongated . transverse line to the row in which they stand, J, often become confluent, either in the line of the r°' and then they form a longitudinal stripe — or tJl1 ^ versely, that is, with the spots in the adjoining and then they form transverse stripes. A spot s°; ^ times breaks up into smaller spots, which still stauc their proper places. ]).
It will be convenient first to describe a perfect b^j, and-socket ocellus. This consists of an intensely b jjv circular ring, surrounding a space shaded so as e%a.C,c\i to resemble a ball. The figure here given has 1
cut cannot exhibit the exquisite shading of the or'r*1^ The ring is almost always slightly broken or intern1!’ (see fig. 56) at a point in the upper half, a little h1 ^ right of and above the white shade on the eacl° 0v ball ; it is also sometimes broken towards the baSe t the right hand. These little breaks have an imp01'^ meaning. The ring is always much thickened, with edges ill-defined towards the left-hand upper c°’
admirably drawn by Dir. Ford, and engraved, but :
GRADATION OF CHARACTERS.
143
^Ifi
■ XIV.
; father bein^ held erect, in the position in which it
Paw Vbls tll,ckened
sun there is 011 the o}j1 i‘lCe of the ball an 'vPi?Ue a^most pure- e mark, which
it,. °s °ff downwards aiv] ^P^e-leaden hue, io. 1's into yellow-
A?4.
tints,
tw _ ^sensibly be- er / < a,'ker and dark- °"ards the lower It
is the ball $v6s . &
fading wliich s°_a<dmirab] y the
%
°f light shining If 0 Cnnvex surface.
r*Xflv, e the balls be
^med.
Pan
Seejj 7TC"> it will be 'at the lower
and i;
rowner
o^tedb
. t Fig. 56. Part of Secondary wing-feather of Argus
*8 indistinctly pheasant, shewing two, a and b, perfect ocelli.
*1 A, B, C, kc., dark stripes running obliquely down,
'Y ^ curved each tu an ocellus.
tpp^le hue from the
:s
[Much of the web on both sides, especially to the left of the shaft, has been cut off.]
fart» which
1'i§ht"er and more leaden; this oblique line runs at light ail,''Gs to the longer axis of the white patch of it) tlj aiid indeed of all the shading ; but this difference Sfc ^afs> which canuot of course be shewn in the 8*^li Ut’ (^°es 11 °t in the least interfere with the perfect US of the ball.48 It should be particularly ob-
» Wjp
'lt|i tlirJS^ri Argus pheasant displays his wing-feathers like a great barest to the body stand more upright than the outer ones,
144
SEXOAL SELECTION : BIEDS.
P.1B1
4
served that each ocellus stands in obvious connect'1^ with a dark stripe, or row of dark spots, for both °c. , indifferently on the same feather. Thus in fig. 50 A' runs to ocellus a; B runs to ocellus b; strip6 L broken in the upper part, and runs down to the J)Lj| succeeding ocellus, not represented in the woodcut .■ - to the nest lower one, and so with tho stripes E uul ,.j
Lastly, the several °(( 1 are separated from , other by a pale s,ir v bearing irregular hi®8 marks.
I will nest de^’11,
the other extreme ot , hPl
series, namely the trace of an ocellus. short secondary " j feather (tig. 57), ne;‘'j to the body, is m®1 ^ like the other with oblique, longl*1'^ nal, rather irregular1 fft, of spots. The lowest d ^ or that nearest the s in the five lower ro" ; i eluding the basal
.1^'
Fig, 57. Basal part of the Secondary wing- feather, nearest to the body.
a little larger thaU other spots in the same row, and a little more t
so that the shading pf the ball-and-socket ocelli ought to be different on tho different feathers, in order to bring out their full e relatively to the incidence of tho light. Mr. T. W. Wood, who jgjl). experienced eye of on artist, asserts (‘ Field,’ Newspaper. May -b’ p. 457) that this is tiie case; but after carefully examining two W°^i)V specimens (the proper feathers from one having been given 1° 1 p’ Mr. Gould for more accurate comparison) I cannot perceive tb®*^ acme of perfection in the shading has been attained; nor can0 to whom I have shewn these feathers recognise the fact.
gradation of characters.
145
<V
4p.
XXV.
It differs also from
ftotefl ;
the r n 11 a transverse direction.
"’ifh s 6r sP°ts by being bordered on its upper side ?l!iy 1Be dull fulvous shading. But this spot is not in of Tn°ro remarkable than those on the plumage I'hfl !l' birds, and might easily be quite overlooked.
•tte
®st higher spot in each row does not differ at all the uPPer ones in the same row, although in
series it becomes, as we shall see,
greatly
the
QOrljg , 1
The larger spots occupy exactly the same Pr- !’ F, . (, ^ P0sbion on this feather as tiiose occupied by the Ily i °Ce^’ °n the longer wing-feathers.
°°kino- to the next two
8fiCi
Kirur
-Pm. I IW iLlv 11
^ati0li ai T wing-feathers,
or three succeeding an absolutely insensible gra- 'Hver ean be traced from one of the above-described stUae sP°ts, together with the next higher one in the ki to a curious ornament, which cannot be called
^tte:
th
0eellus, r term.
and which I will name, from the want of a > an “elliptic ornament,” These are shewn
We here see
"wei,ai a-'c°mpanying figui’e (fig. 58).
'Clique rows, A, B, C, D (see the lettered diu-
\\ of' c’’ °1 dark spots of the usual character. Each
d'e i.fPots rims down to and is connected with one of ■ •
H
str
Jptic
ornaments, in exactly the same manner as
■*« l'Pe ln fig. 56 runs down to, and is connected with, *0"-, j. f ball-and-socket ocelli. Looking to any one *c‘^er „ lnistauee, B, the lowest spot or mark (&) is
th
aild considerably longer than the upper spots, bUt left extremity pointed and curved upwards. ■ a tatl i mar^ abruptly bordered on its upper side "hlr ler broad space of richlv-shaded tints, beginning tllif!larrow brown zone, which passes into orange, lo 111 to a pale leaden tint, with the end towards |6sPeet Paler' This mark corresponds in every
k-t fbe larger, shaded spot, described in the
graph (fig. 57)} but is more highly deve-
v°l.
It.
146 . SEXUAL SELECTION : BIRDS. 1
. u $
loped and more brightly coloured. To the rig*11' .. j above this spot (b), with its bright shading, the1® ^ long, narrow, black mark (e), belonging to the f‘ , row, and which is arched a little downwards so ^ face (h). It is also narrowly edged on the lowe1 ^ with a fulvous tint. To the left of and above c, 111
A
b c
tig. 58. Portion oi one of the Secondary wing-feathers near to the body* jiii!-'1 so-called elliptic ornaments. The right-hand figure is given merely ^ for the sake of the letters of reference.
A, B, C, ko. Hows of spots running down I c. The next succeeding spot °r tomnug U,e orna- the same row.
d. Apparently a broken p1’0, jj. the spot c in the same rtf'
meats.
h. Lowest spot or mark in row B.
same oblique direction, but always more or less j, r from it, there is another black mark (d). This &a‘\ iH generally sub-triangular and irregular in shape- the one lettered in the diagram is unusually 11,1 J ;l elongated, and regular. It apparently consist® ^1 lateral and broken prolongation of the mark ( ■
gradation of characters.
147
c«,
it.
Xiv.
>nf,
er
^Ci
from
rt|1(,^(ling upper spots; but I do not feel sure of this. '•ti'% t*u’ee marks, l, c, and d, with the intervening s^ades, form together the so-called elliptic orna.- t)|6 1'hese ornaments stand in a line parallel to U.la and manifestly correspond in position with the
traces of similar prolongations from the
^d-socsket ocelli. Their extremely elegant appear- ed be appreciated in the drawing, as the orange
r<iarh Cuc^eEL tints, contrasting so well with the black Set" Caun°f be shewn.
tyi 'Vfei1 one °f the elliptic ornaments and a perfect d js docket ocellus, the gradation is so perfect that \htSCai'Cely P0ssible to decide when the latter term to be used. I regret that I have not given an
K
<ht.
Vlu°Ual drawing, besides fig. 58, which stands about ‘ y 111 the series between one of the simple spots Perfect ocellus. The passage from the elliptic ■hid e,lt iuto an ocellus is effected by the elongation hlaep tdter curvature in opposed directions of the lower h CTk (h), and more especially of the upper one hijm 'J’^her with the contraction of the irregular sub- 1 ar or narrow mark (d), so that at last these ^ipti(^nU-r^8 become confluent, forming an irregular jj. llno- This ring is gradually rendered more circular and regular, at the same time in- 7 ln diameter. Traces of the junction of all 'd'pep 011§ated spots or marks, especially of the two Can still be observed in many of the most
% -elli. The broken state of the black ring on Tf S^6 ocellus in fig. 56 was pointed
■) U'regular sub-triangular or narrow mark
'“ho,! es% forms, by its contraction and equal i- j’ldiOf’ ■ . 6 thickened portion of the ring on the left
f e °f the perfect ball-and-socket ocellus. The ai't of the ring is invariably a little thicker than
l 2
14S
SEXUAL SELECTION: BIRDS.
lit*
n # the other parts (see fig. 56), and this follows fro® ^
lower black mark of the elliptic ornament (b) 1')'
been originally thicker than the upper mark (c). ^
step can be followed in the process of confluence
modification ; and the black ring which surrounds th£! . f
of the ocellus is unquestionably formed by the
and modification of the three black marks, l, c, d, c>* ,h
elliptic ornament. The irregular zigzag blacl between the successive ocelli (see again fig. 56) plainly due to the breaking up of the somewhat 1
regular but similar marks between the elliptic inents.
✓ ,4-
The successive steps in the shading of the ba^':' .;i socket ocelli can be followed out with equal cle0,1^^ The brown, orange, and pale-leaden narrow zones " ^ border the lower black mark of the elliptic on®” | can be seen gradually to become more and more son ( and shaded into each other, with the upper lights1* towards the left-hand comer rendered still light®'
■4*
But even in the most
to become almost white.
ball-and-socket ocelli a slight difference in the 1 p though notin the shading, between the upper and parts of the hall can be perceived (as was before ' ,,,,
ciallv noticed), the line of separation being «5 ’ ■’ " - ’sin.;
ill”;
in the saino direction with the bright coloured of the elliptic ornaments. Thus almost every 11,1 detail in the shape and colouring of the ball-aod"'1 jp ocelli can be shewn to follow from gradual cha'1?, j)j0 the elliptic ornaments ; and the development 0 ,;■/ latter can. he traced by equally small steps ft-0”' ji)
p (fib' aide*
union of two almost simple spots, the lower one having some dull fulvous shading on the upper r
ml - X *x* _ -I* , 1 ..
’ * => - ouuuu,6 Uii W.t, MV
The extremities of the longer secondary te which bear the perfect ball-and-socket ocelli a[e ^ liarlv ornamented. (Fig. 59.) The oblique longitu
c«
4p.
Siv.
gradation of characters.
149
Stfj'
^Ht[ SU(Merily cease upwards and become confused, («) js °Ve this limit the whole upper end of the feather 'JV]j C"Vere(1 with white dots, surrounded by little
|'IU8S! standing on a hie ,.e str4)e belonging to is j PP»most ocellus
J*P**er
MVlththe
be^01’° stated, this ,%l6(} ( [ Pai't is apparently
'JV a hm-iton
%
%,
\
4>id
“sen,
same row. From Ce of the
a thi i UI T,lle upper
tll6 '6ri6(i Part of the
J°iigu 'Pperruost ocellus, l'sl)ects 'etlect iu all other jll(i beejj UjhJefll’s as if its top , 'vo„] |ol'1ique]y sliced off.
t]'y 0l|e tLmk’ PerPlex
) | 6 Plum ' l° ^iieves that Nnm 1 of the Argus- ii°'Vse®it"f8 ereateci as we „ ^etfew ’ t0 aecount for the
v^UiOsf C’0n(htion of the Vf °8t ocelli a feath,
dark ground. Even the
Q>)
ated only by a 8ll0rt irregular
black
hsiy
V
ip'-.,
fihipeVei;° base. As this %bovS t'1Us ah™ptly cut "e can understand, Vv <lt has gone before, ’W]je ls that the upper I'Vut ;tC ^Ult °i the ring is lls: w 11 ^©uppermost ocel-
iillSver:; lue usual, curved,
^iou'nf!, broken hr0' ih+i 01 next higher , sa
Fig. 69. Portion near summit of one of the Secondary wing-feathers, bearing perfect ball-and-socket ocelli.
a. Ornamented upper part.
b. Uppermost, imperfect ball-and-socket
ocellus. (The shading above the white mark on the summit of the ocellus Is here a little too dark.)
c. Perfect ocellus.
I should add that in the secondary 61 farthest from the body all the ocelli are
150
SEXUAL SELECTION: BIRDS.
pi*'
smaller and less perfect than on the other f6^1^- with the upper parts of the external black ring®^,, ficient, as in the case just mentioned. The imp® ^ tion here seems to he connected with the fact tin1 spots on this feather shew less tendency than ngU1’ ^ become confluent into stripes ; on the contrary, they ^ often broken up into smaller spots, so that two or rows run down to each ocellus. _ $
be
We have now seen that a perfect series can ^
V
lowed, from two almost simple spots, at first '^.Ji distinct from each other, to one of the wonderful s and-socket ornaments. Mr. Gould, who kindly some of these feathers, fully agrees with me in tke ^ pleteness of the gradation. It is obvious that the ^ ^ in development exhibited by the feathers on the bird do not at all necessarily shew us the steps " A have been passed through by the extinct progeu1 ' t|1( the species ; but they probably give us the clue actual stops, and they at least prove to denn'^jil tion that a gradation is possible. Bearing 111 ||f
how carefully the male Argus pheasant display!: plumes before the female, as well as the man) n’ rendering it probable that female birds prefer tin ^ attractive, males, no one who admits the age'1 ' jtl' sexual selection, will deny that a simple dark sp'-’ ^ some fulvous shading might be converted, the approximation and modification of the a‘ spots, together with some slight increase of cf^ into one of the so-called elliptic ornaments. latter ornaments have been shewn to many and all have admitted that they are extremely 1^ fv some thinking them even more beautiful th1 _ pr ball-and-socket ocelli. As the secondary P^u^d came lengthened through sexual selection, ‘l ^ the elliptic ornaments increased in diameter*
'•Up
XIV.
GRADATION OF CHARACTERS.
151
Co]o
apparently became less bright ; and then the itn^^tation of the plumes had to be gained by pf(j(!'°Verneuts in the pattern aud shading ; and this atl(|tSs ^,as been carried on until the wouderlul ball- ean s°cket ocelli have been finally developed. Thus we Understand — and in no other way as it seems to on y present condition and origin of the ornaments 16 'ring-feathers of the Argus pheasant.
p
^i*0'1' the light reflected by the principle of grada- fr(lli 11 ’ from what we know of the laws of variation ; of 1 fhe changes which have taken place in many
iiilt
d;
VVUitn “U.IVJ jy - j
r domesticated birds; and, lastly, from the cha- 01 (as we shall hereafter more clearly see) of the
ku]
Mature
_ plumage of young birds — we can sometimes babjCate " ith a certain amount of confidence, the pro- bri|l? 8teps by which the males have acquired their plumage and various ornaments; yet in many are involved in darkness. Mr. Gould several
■$es
jr>
ago
pointed out to mo a humming-bird,
the
fetpv lcte benjamini, remarkable from the curious dif-
v J
presented by the two sexes. The male, besides dd gorget, has greenish-black tail-feathers, with Wit!*1 ceniral ones tipped with white ; in the female, oatlie 1 >nost of the allied species, the three outer tail- Ha.n'i1’8 °n each side are tipped with white, so that the
t|JSUd
X 1 tuv 7
four central, whilst the female has the six
What
Jeiw /? ...
kaljp^ ai weathers ornamented with white tips.
0f the . case cu ri ous is that, although the colouring titiffs do 1 differs remarkably in both sexes of many dmmming-birds, Mr. Gould does not know a bfio ‘sPecies, besides the Urosticte, in which the male le *°ur central feathers tipped with white.
e of Argyll, in commenting on this case,49
The Ifuk
49 1 Tlio Reign of Law,' 1807, p. 247.
152
sexual selection: birds.
PA**1
passes over sexual selection, and asks, « What expl^l “ l'011 ^oes the law of natural selection give of ®u^ “specific varieties as these?” He answers “»0lJ “whatever;” and I quite agree with him. Bid ^ this be so confidently said of sexual selection ? S^'f, in how many ways the tail-feathers of humming'1"1'1.' differ, why should not the four central feathers varied in this one species alone, so as to have acq^ white tips? The variations may have been gradin'*’^ somewhat abrupt as in the case recently given of humming-birds near Bogota, in which "certain ifl j viduals alone have the “central tail-feathers tipf, “with beautiful green.” In the female of the • r'.^ ticte 1 noticed extremely minute or rudiments! tips to the two outer of the four central black t:1‘ , feathers ; so that here we have an indication of cha"h of some kind in the plumage of this species. If we g1’8,, the possibility of the central tail-feathers of the varying in whiteness, there is nothing strange in sll!ft. variations having been sexually selected. The tips, together with the small white ear-tufts, cori^1'1! j add. as the Duke of Argyll admits, to the beauty0* j'r male ; and whiteness is apparently appreciated by ot ^ birds, as may be inferred from such eases as the ^ w hite male ot the Bell-bird. The statement ni^d'3 . Sii h. Heron should not be forgotten, namely that peahens, when debarred from access to the pied pe^0.^ would not unite with any other male, and during 1 K t season produced no offspring. Nor is it strange f'b variations in the tail-feathers of the Urosticte liave been specially selected for the sake of ornao1'8., toi the next succeeding genus in the family tak°B ^ name ofMetallura from the splendour of these featl*' , Mr. Gould, after describing tlie peculiar plumage of ^ Uiosticte, adds, 1 that ornament and variety is the
GRADATION OF CHARACTERS.
153
ClUp,
XIV.
Ob'
ad Jeet> I have myself but little doubt.” 50 If this be dJM we cau perceive that the males which were -in t,le lnost elegant and novel manner would f0l. ® Sa-ined an advantage, not in the ordinary struggle Cq^16’ hut in rivalry with other males, and would itihg <iUently have left a larger number of offspring to d their newly- acquired beauty.
50 ‘Introduction to the Trochilidse/ 18G1, p. lid.
154
SEXUAL SELECTION : BIRDS.
pAl*1
CHAPTEE XV.
Bikds — continued.
J
Discussion why the males alone of some species, and both sei^ jf other species, are brightly coloured — On sexually-limi^ m- heritaiice, as applied to various structures and to bri§ J coloured plumage — Nidification in relation to colour — b<lSi nuptial plumage during the winter.
We hare in this chapter to consider, why with kinds of birds the female has not received the fil , ornaments as the male ; and wliy with many both sexes are equally, or almost equally, ornament^, In the following chapter we shall consider why in s° J few rare cases the female is more conspicuously cob1'1* than the male. t
In my ‘ Origin of Species ’ 1 I briefly suggested the long tail of the peacock would be inconvenient ** ■, the conspicuous black colour of the male capeu'3', , dangerous, to the female during the period of incub^ f, and consequently that the transmission of these eJ19^, teis liom the male to the female offspring had ^ <
checked through natural selectiou. I still think this may have occurred in some few instances : hut
>00
matme reflection on all the facts which I have
able to collect, I am now inclined to belie'® when the sexes differ, the successive variations ™ generally been from the first limited in their tranf ,, sion to the same sex in which they first appeared. my remarks appeared, the subject of sexual coloi'at‘
1 Fourth edition, 1SGG, p. 241.
SEXUALLY-LIMITED INHERITANCE.
155
c*
XV.
8Uc
Jjj ^een discussed in some very interesting papers by ' Wallace,2 who believes that in almost all cases the CessWe variations tended at first to be transmitted t]‘, ally to both sexes ; but that the female was saved, o "Ugh natural selection, from acquiring the conspicu- , -W, of the male, owing to the danger which she riV ^ms lmve incurred during incubation, dil'c 18 vlew necessitates a tedious discussion on a f,i point, namely whether the transmission of a be r‘lc*ei') which is at first inherited by both sexes, can of sp®equently limited in its transmission, by means Action, to one sex alone. We must bear in mind,
Sho,..
tio
Qewn
4u
the
k
in the preliminary chapter on sexual selec- characters which are limited in their de- t P’nent to one sex are always latent in the other, ^agioary illustration will best aid us in seeing ■ulty of the ease: we may suppose that a
diffi
tlU;('U:I' wished to make a breed of pigeons, in which M)i]?aleS alone should be coloured of a pale blue, Wjtj 1 tlle females retained their former slaty tint. As tiitt liIgeous characters of all kinds are usually trans- to ^ to both sexes equally, the fancier would have 8e ‘ •f to convert this latter form of inheritance into ^''limited transmission. All that he could do to persevere in selecting every male pigeon Was iu the least degree of a paler blue ; and the
Mi*41
a ]0 result of this process, if steadily carried on for time> au(l if the pale variations were strongly strJ(:.j! 11,-11 or often recuri'ed, would be to make his whole pell i°^ a ^‘S'bter blue. But our fancier would be com- bing1 match, generation after generation, his pale with slaty females, for he wishes to keep the
* hi
>8, p^tminster Review,' July, 1867. ‘ Journal of Travel,’ vol.
156
SEXUAL SELECTION : BIRDS.
p+rJ 1
latter of this colour. The result would generally V the production either of a mongrel piebald lot, or &0l} probably the speedy and complete loss of the pale-b^ colour, for the primordial slaty tint would be ti'3°‘" nutted with prepotent force. Supposing, however, some pale-blue males and slaty females were prodfl®^ during each successive generation, and were crossed together ; then the slaty females would h**? if I may use the expression, much blue blood m veins, for their fathers, grandfathers, etc., will all h9fC been blue birds. Under these circumstances it is ceivable (though I know of no distinct facts render^ it probable) tliat the slaty lemales might acquit > strong a latent tendency to pale-blueness, that t1'6' would not destroy this colour in their male offspr^| then- female offspring still inheriting the slaty tint. 1 so, the desired end of making a breed with the sexes permanently different in colour might be ga^e<‘ The extreme importance, or rather necessity, of ^ desired character in the above case, namely, pale-b^’j^ ness, being present though in a latent state in ll‘‘ emale, so that the male offspring should not be de^ riorated, will be best appreciated as follows : the m3^ of Sccmmerring’s pheasant has a tail thirty-seven in length, whilst that of the female is only eight. ind,eSJ the tail of the male common plieasant is about inches, and that of the female twelve inches long. if the female Scemmerring pheasant with her short were crossed with the male common pheasant, can be no doubt that the male hybrid offspring 'V0«l1 have a much longer tail tlian that of the pure offspring f the common pheasant. On the other hand, if the fen^1' common pheasant, with her tail nearly twice as long &s that of the female Scemmerring pheasant, were cms6e with the male of the latter, the male hybrid offd>ri'^
SEXUALLY-LIMITED INHERITANCE.
157
‘up.
Xv.
Q^slJ1'ii|JaVe a muc^ ^lor^er tail than that of the pure Q( j? ^mmcrring’s pheasant.3 5la]es aileier, in order to make his new breed with the a decided pale-blue tint, and the females ltn- ^tfiTw ’ would have to continue selecting the males Si! ,many generations ; ami each stage of paleness ^k‘nt ■ laVe to ^xe(l in the males, and rendered t'le females. The task would be an extremely Sy 0ne> and has never been tried, but might pos- sCCCOed. The chief obstacle would be the early sity ^plete loss of the pale-blue tint, from the neces- Wtej reiterated crosses with the slaty female, the IJale.Lil0t having at first any latent tendency to produce On p 6 offspring.
^Vet ,e °ther hand, if one or two males were to vary (.fi Sl.'"hOy in paleness, and the variations were ^ hrst limited in their transmission to the male of making a new breed of the desired
If, '0]'hl be easy, for such males would simply have * e°ted and matched with ordinary females. An
ST
3,01 ls ease has actually occurred, for there are
of Oie
f, e are
s
pigeon in Belgium 4 in which the males
t!lr; ’/Nations
marked with black striae. In the case of the
'hit
edt.
of colour limited in their transmission to sex habitually occur. Even when this form of
some
! th6 an<:6 prevails, it might well happen that J9 tpai, f.Ce<Jssive steps in the process of variation might I e5le<^ to the female, who would then come to n'eeds VQ a 8%kt degree the male, as occurs in some 0 the fowl. Or again, the greater number, but
fe,rib ?aXs that the tail of the female Flmsianns Sivmmerringii
i^g1110™8 l°n& ‘ Planches coloriees,’ voL v. 1838, p. 487 and l>. ]J^6 colnaSUremeilta ahore given were made lor mo by Mr. Sclater. , , 12] ltQon Pheasant, see Macgillivray, 1 Hist. Brit. Birds,’ vol. i.
■Ch;
apuis
‘Le Pigeon Voyagcur Beige,’ 1865, p. 87.
158
SEXUAL SELECTION : BIRDS.
P^1 j {0
not all, of the successive steps might be transfer^ ^ both sexes, and the female would then closely reseIf j. the male. There can hardly be a doubt that th'3 , the cause of the male pouter pigeon having a some" larger crop, and of the male carrier pigeon having what larger wattles, than their respective females fanciers have not selected one sex more than the 0 ^ and have had no wish that these characters shorn1 more strongly displayed in the male than in the fe^ yet this is the case with both breeds. m
The same process would have to be followed, a011.!,,! same difficulties would be encountered, if it were desl to make a breed with the females alone of soWe 1 colour. j|i
Lastly, our fancier might wish to make a breed 'vV the two sexes differing from each other, and both the parent-species. Here the difficulty would ho ^ treme, unless the successive variations were fro'11 J first sexually limited on both sides, and then there be no difficulty. We see this with the fowl; tiff8 (jy two sexes of the pencilled Hamburghs differ g^^rj- from each other, and from the two sexes of the 9 ginal Gallus lankiva ; and both are now kept c°iv ^i. to their standard of excellence by continued sek1(t „ which would be impossible unless the distinctive oh ^ ters ol both wore limited in their transmission. ^ Spanish fowl offers a more curious case ; the und1, ji;, an immense comb, but some of the successive vari^Vy by the accumulation of which it was acquired, ; to have been transferred to the female ; for she h?^ comb many times larger than that of the females otj,) parent-species. But the comb of the female diffef#j(,ji
one respect from that of the male, for it is apt over; and within a recent period it has been
to
off
de1"
by the fancy that this should always be the case> 1
Cn
4p. v
XV.
SEXUALLY-LIMITED INHERITANCE.
159
Slkees(, l
Pino. las quickly followed the order. Now the lop- comb must be sexually limited iu its trans- it^ n> otherwise it would prevent tbe comb of the ul^ fr°m being perfectly upright, which would be ent to every fancier. On the other hand the it Sr,^ lttU;ss of (he comb in the male must likewise be Olly-limited character, otherwise it would prevent of the female from lopping over.
Wit]. foregoing illustrations, we see that even
°st unlimited time at command, it would be
X retuely difficult and complex process, though &ne not impossible, to change through selection "itr 01111 of transmission into the other. Therefore, to i)r| distinct evidence in each case, 1 am unwilling
11 that this has often been effected with natural On the other hand by means of successive
s a<V
ill t.j which were from the first sexually limited transmission, there would not be the least "o]OU|i y in rendering a male bird widely different in I** 111 any other character from the female; the ffiodif: left unaltered, or slightly altered, or specially
j. . idr the sake of protection, fivajj. ri?^t colours are of service to the males in their "'I'etfi Vlt^ °tder males, such colours w'ould be selected, :'Uiru; 61 01 not they were transmitted exclusively to the
oft.
1 §ex,
to
Consequently the females might be expected
Partake of the brightness of the males to a
sPeCj0s 0r less degree ; and this occurs with a host of
fitted" ^ nil the successive variations were trans-
Oiiflit,,,. e9.ually to both sexes, the females would be “winr ■ -
%
cUrs ^dshable from the males; and this likewise °f hira^l^1 many birds. If, however, dull colours were
V
|%S JluP(|rtance for the safety of the female during 'viUel| l0ll.: as "dth many ground birds, the females ^aried in brightness, or which received through
160
SEXUAL SELECTION : BIBDS.
PA*^
inheritance from the males any marked access!01’
fliji
brightness, would sooner or later be destroyed- _ the tendency in the males to continue for an inde11’1^, period transmitting to their female offspring their 0 brightness, would have to be eliminated by a ehaflf^ the form of inheritance; and this, as shewn by previous illustration, would be extremely difficult- , p more probable result of the long-continued destm0 ^ of the more brightly-coloured females, supposing equal form of transmission to prevail, would be tl'e .
sening or annihilation of the bright colours of the
owing to
their continually
crossing with the •-
females. It would be tedious to follow out ^ ^ other possible results; but I may remind the reade!j(tl| shewn in the eighth chapter, that if sexually-i’"1* jj1
variations in brightness occurred in the females,
they were not in the least injurious to them ^ sequenfly were not eliminated, yet they would 110
3D
if
<D'
favoured or selected, for the male usually accept female, and does not select the more att racin'® * jjo viduals ; consequently these variations would be 1 to be lost, and would have little influence 011 character of the race ; and this will aid in ing for the females being commonly less brig coloured than the males.
In the chapter just referred to, instances were c and any number might have been added, of van1*
$
&
l\V>
occurring at different ages, and inherited at the age. It was also shewn that variations which oce*’1^ iu lit
which they first appeared ; whilst variations occ,tt’^, early in lit© are apt to be transmitted to both £f
V ,<#
not that all the cases of sexually-limited trans11’’ ^ cau thus be accounted for. It was further she"1’ ,,;].-! if a male bird varied by becoming
brighter
SEXUALLY LIMITED INHERIT AX GE.
161
C«.
Ap.
XV.
a;re P SUch variations would be of no service until the titj()li°r repvoduction had arrived, and there was compe- 'vliicj ( ‘e^vveen rival males. But in the case of birds tlie llVe the ground and which commonly need
Vf?tecti0n dull colours, bright tints would be far e dan:
to
th
Serous to the young and inexperienced than
vhi(1(t .a^u^ males. Consequently the males which 111 brightness whilst young would suffer much ti0ft Ucti°n and be eliminated through natural selec- ting ’ °u the other hand the males which varied in turner when nearly mature, notwithstanding that VjVe ere exposed to some additional danger, might sur- 'vouic|in<l b'°m being favoured through sexual selection, J&aj bl’°create their kind. The brightly-coloured young -einbr destroyed and the mature ones being suc- of la their courtship, may account, on the principle .lotion existing between the period of variation itiail 16 form of transmission, for the males alone of co]OUrs lrds, having acquired and transmitted brilliant ah6atls their male offspring alone. But I by no th6 j. Wl8n to maintain that the influence of age on Hie transmission is indirectly the sole cause of
Of JIeat difference in brilliancy between the sexes ^ a}T birds.
b 'Vl^b all birds in which the sexes differ in colour, it bee^ Ill^erestiug question whether the males alone have Wijjg 1 °difled through sexual selection, the females !lt oul ° as as this agency is concerned, unchanged ^ Partially changed ; or whether the females have J,6l-ially modified through natural selection for the j Protection, I will discuss this question at con- *hp0rt e length, even at greater length than its intrinsic ance deserves ; for various curious collateral points \'oj_ be conveniently considered.
162
SEXUAL SELECTION: BIRDS.
PART1
Before we enter on the subject of colour,
ioPs’
especially in reference to Mr. Wallace’s conclns1' it may be useful to discuss under a similar p°'u^ ^
breed of fowls formerly existed in Germany 5 in
view some other differences between the sexes- ,
•5 i„ wll'CJ
the bens were furnished with spurs; they were layers, but they so greatly disturbed their nests '' 1 .f their spurs that they could not be allowed to sit ou 1 own eggs. Hence at one time it appeared to w° 1' , itli the females of the wild Galh’118,0^
tbtir
bable that w . (l
the development of spurs had been checked tin'0’1' natural selection, from the injury thus caused to \ „ nests. This seemed all the more probable as the "j1
,ti<”)'
spurs, which could not be injurious during uidificil are often as well developed in the female as jrl ^ male ; though in not a few cases they are rather ;|1' in the male. When the male is furnished with y- spurs the female almost always exhibits rudime®^^
them, — the rudiment sometimes consisting of a scale, as with the species of Gallus. Hence it be argued that the females had aboriginally been nished with well-developed spurs, but that these j subsequently been lost either through disuse or nil*U , - selection. But if this view be admitted, it would , to be extended to innumerable other cases ; and lt
plies that the female progenitors of the existing '1 - bearing species were once encumbered with j urious appendage. uj,
In some few genera and species, as in Gallop^
4
Acomus, and the Javan peacock ( Pavo muiiG^s): * females, as well as the males, possess well-de'e spurs. Are we to infer from this fact that they
5 Beehstein, 1 Naturgesch. Deutschlands,’ 1703, B. iii.
33?-
DEVELOPMENT OF SPUES.
163
<W,
XV.
by ,a different sort of nest, not liable to be injured So y Cl1 sl)Urs) from that made by their nearest allies, tbf.i,.'at t^lere bus been no neerl for the removal of spurs? Or are we to suppose that these fe- especially require spurs for their defence ? Jt
aeir >l6s
b a 'Specially require spurs for their defence ? j frid i°le Pr°bable conclusion that both the presence
M aij- 1
®Dtly a'vs °i inheritance having prevailed, independ- ''’bi°/ nafrir{fr selection. With the many females *( 1 spurs appear as rudiments, we may conclude
'V^ch'S°me ^ew ^ie successive variations, through v,Uy tliey were developed iu the males, occurred S^ly iu life, and were as a consequence trans- !° fr*° females. In the other and much rarer '-n which the females possess fully developed ’ "e uiay conclude that all the successive yaria- 'Vallv""ere fr’uusferred to them; and that they gra- acquired the inherited habit of not disturbing
h
bests'
V ,ir ^°cal organs and tbe variously-modified feathers lf)t Us^ Ucing sound, as well as the proper instincts \eh ° ^em> often differ in the two sexes, but are the same in both. Can such differences be H||d ^ . tor by the males having acquired these organs 'hbjgj.- . mcts, whilst the females have been saved from V;nS them, on account of the danger to which
vyr - ~ vr,A U/V.WUJ-1P vi uaugci l\J VVIUCJL
have been exposed by attracting the at- °t birds or beasts of prey ? This does not 'Hir^ llle probable, when we think of the multitude ‘*ir v ,'vhich with impunity gladden the country with lCes during the spring.6 It is a safer conclu-
VVea m .
1 p. aiTington, however, thought it probable (‘ Phil. Transact.’ ) that few female birds sing, because the talent would have
M 2
104
sexual selection: birds.
PaR1
It
f stiec’^
sion that as vocal and instrumental organs are ot 4 service only to the males during their courtship) i|(j
organs were developed through sexual selection ^ continued use in this sex alone — the successive tions and the effects of use having been from th® ^ limited in their transmission in a greater or less deo to the male offspring. ^ \y
$
tits*
Many analogous cases could be advanced ; llir
J}.
stance the plumes on the head, which are geDe ^ of longer in the male than in the female, someth®1' j„ equal length in both sexes, and occasionally abse’h^ the female, — these several cases sometimes occ®^ ,(i in the same group of birds. It would be difr0" ^ account for a difference of this kind between the ^ ^ on the principle of the female having been beneth^ possessing a slightly shorter crest than the male, consequent diminution or complete suppression i,]e natural selection. But. I will take a more fa 1° case, namely, the length of the tail. The of the peacock would have been not only inco»'r but dangerous to the peahen during the period o bation and whilst accompanying her young- . (I'1 there is not the least a priori improbability t ^ development of her tail having been checked t
natural selection.
•I)®!'
But the females of van0111’
sauts, which apparently are exposed on their op1’1^.
/
to as much danger as the peahen, have tail- 0 ^ siderable length. The females as well as f'10
of the Menura euperba have long tails, and fluff a domed nest, which is a great anomaly in so
m
.iii.
bird. Naturalists have wondered how the fc®®1 ^t1 nura could manage her tail during incubation >
— ^ si^(
been dangerous to tliem during incubation. He adds, tb»^ view may possibly account for the inferiority of the female in plumage.
XV.
LENGTH OF TAIL IN FEMALE.
165
known7 that she “enters the nest head first, “ |j j'ken turns round with her tail sometimes over 1 i'h .C'k> knt more often bent round by her side. “ t0j,)s 7,i time the tail becomes quite askew, and is a b^le guide to the length of time the bird lias 1 S|tting-.” Both sexes of an Australian kingfisher
(Ju .une- Joott
S1jlvia) i. .sHiermri . ,i „
have the middle tail-leathers greatly h0£ ened; and as the female makes her nest in a If jj k|r‘S3 feathers become, as I am informed by Mr. hi ktttpe, much crumpled during nidification.
. iese two cases the great length of the tail-feathers
m some degree inconvenient to the female ;
4re 8 111 both species the tail-feathers of the female lie . _ 1 ewhat shorter than those of the male, it might Vpjj. 8Ued that their full development had been pre- CitSrig c . kirough natural selection. Judging from these had |j ^ " kh the peahen, the development of the tail Of ^ en decked only when it became inconveniently W. gey°nsly long, she would have acquired a much hot tad than she actually possesses; for her tail is hs tp eai,y so long, relatively to the size of her body,
of
that
f 01 many female pheasants, nor longer than that that finale turkey. It must also be borne in mind, tin. accordance with this view as soon as the tail of d len became dangerously long, and its develop-
*n.
lhi
keVfc ' leacted on her male progeny, and thus have *be peacock from acquiring his present mag- °t t]le tram- We may therefore infer that the length btp ad in the peacock and its shortness in the pea- d>ale result of the requisite variations in the
’tfi'sn,.; a'lng been from the first transmitted to the male P alone.
Was
consequently checked, she would have con-
Mr. Ramsay, in ‘ Proc. Zoolog. Soc.’ 1S6S, p. 50.
16b* sexual selection: bikds. PAltI
We are led to a nearly similar conclusion "'h
respect to the length of the tail in (he various sPeC!.,
of pheasants. In the Eared pheasant (Crossop1
- -
the cotavf
auritim ) the tail is of equal length in both seS‘
namely, sixteen or seventeen inches; in the co-
’ alft
P
pheasant it is about twenty inches long in the 10,1 and twelve in the female; in Soemmerring’s phe®®9 thirty-seven inches in the male, and only eight i® . female ; and lastly in Eeeve’s pheasant it is someth actually seventy-two inches loug in the male and teen in the female. Thus in the several specie®* j(, tail of the female differs much in length, irrespect‘vjvr of that of the male ; and this can be accounted as it seems to me, with much more probability, hy -v laws of inheritance, — that is by the successive v® ^ tions having been from the first more or less cle-^ limited in their transmission to the male sex,— tin1® v the agency of natural selection, owing to the long'd1^., tail having been injurious in a greater or less deg1 to the females of the several species.
Wo may now consider Mr. Wallace’s argument __ regard to the sexual coloration of birds. He bel'c^| that the bright tints originally acquired through selection by the males, would in all or almost all have been transmitted to the females, unless the b ference had been checked through natural sel©®^,,; I may here remind the reader that various bearing on this view have already been given 11 'm.,
l \*te'
reptiles, amphibians, fishes, and lepidoptera. Wallace rests his belief chiefly, but not exclusive1- ’ we shall see in the next chapter, on the following 1 ment,8 that when both sexes are coloured in a strik1®*
‘ Journal of Travel,’ edited by A. Murray, vol. i. 186S, !>•
COLOUR AND NIDIFICATION.
167
“*U.p
p- Xv.
Con?icUoils manner tlie nest is of such a nature as to '"Ofttr ^le 8‘tt*uo bird J but when there is a marked Say >)S,
%
ast of colour between the sexes, the male being the female dull-coloured, the nest is open and bird to view. This coincidence.
f.^b'S tlle sittin_ tV-jjj . as it goes, certainly supports the belief that the H0(!. fs which sit on open nests have been specially Hi], ! <;<1 for the sake of protection. Mr. Wallace $0^ 8 i'bat there are, as might have been expected, 'vbet| ex<3ePtious to his two rules, but it is a question to ; ler tbe exceptions are not so numerous as seriously Jalidate them.
of ^ ere is in the first place much truth in the Duke 0ol)s remark9 that a large domed nest is more 0abhyCtlOUs to aa enemy, especially to all tree-haunting tnist 0l'°Us animals, than a smaller open nest. Nor Ufcsts. "e forget that with many birds which build open Hor, llla*cs Sit 0,1 the eSSs all(i in feeding the HnU(6 as well as the females : this is the case, for in- V,ls ! with Pyranga eediva ,10 one of the most splendid Ul)d tl 111 t'le United States, the male beiug vermilion, c°lon .*e ^eniaie light brownish-green. Now if brilliant sittiJ ^lad been extremely dangerous to birds whilst Si*0* their open nests, the males in these cases UlVe suffered greatly. It might, however, be of Varamou*t importance to the male to be bril- 1 c°loured, in order to beat his rivals, that this
°U1(1 a, -
0re than compensate for some additional danger. VaUace admits that with the King-crows (Di- fltioles, and Pittidie, the females are conspi- ^tgfcg "I’ coloured, yet they build open nests ; but he llt the birds of the first group are highly pug-
8 ‘ J
ll of Travel,’ edited by A. Murray, vol. i. 18CS, p. 281.
- ‘ Oruitiiologioal Biography,’ vol. i. p. 233.
168
SEXUAL SELECTION : BIRDS.
PA***
nacious and could defend themselves ; that those
of*
second group take extreme care in concealing 1‘ r open nests, but this does not invariably hold g°0< Ll and that with the birds of the third group the are brightly coloured chiefly on the under surface. ^ sides these cases the whole great family of p1'®60 ,, which are sometimes brightly, and almost always c- spicuously coloured, and which are notoriously 1^%, the attacks of birds of prey, offers a serious excel'^j
yd
in'1'
¥
to the rule, for pigeons almost always build open
exposed nests. In another large family, that
of
Humming-birds, all the species build open nests? with some of the most gorgeous species the sexeS ^ alike ; and in the majority, the females, though ^ brilliant than the males, are very brightly colou „ Nor can it be maintained that all female hum11’ ^ birds, which are brightly coloured, escape detect)011 , their tints being green, for some display on their ufl
surfaces red, blue, and otlicr colours.12 A
str*8
In regard to birds which build in holes or cons
3r)'
i'
besides concealment are gained, such as shelter 1
domed nests, other advantages, as Mr. Wallace
the rain, greater warmth, and in hot countries ]l)0 tion from the rays of the sun ;13 so that it is no
.Hanl'501
io!>"
i
11 Jordon, ‘Birds of India,’ vol. ii. p. 108. Gould’s 1 tlie Birds of Australia/ vol. i. p. 463. ^
1- For instance, the female Eupefomena mocrouta has the lllj (id tail dark blue with reddish loins ; the female Lampornis porrIJg{ i‘‘j is blackish-green on the upper surface, with the lores and aid' * tfP throat crimson ; the female h 'ulampis jugulctris has the top 1 , P1' ami hack green, hut the loins and the tail are crimson. At ;i 1 \ ^
instances ot highly conspicuous females eonld he given. Sec Mr- magnificent work on this family. . jpjfl1'
** Mr. Salvin noticed in Guatemala (‘Ibis,’ 1864, p. 375) ***,, vi'<j ming-birds were much more unwilling to leave their nests ° liot weather, when the sun was shining brightly, than du>lflo cloudy, or rainy weather.
COLOUR AND NIDIFICATION.
169
VXv
°bjec,t-
oW JOa bis Y^ew that many birds having both sexes tr0t^lely coloured build concealed nests.14 The female {Buceros), for instance, of India and Africa ^Protected, during nidification, with extraordinary Vl •the umle l'biister.s up the bole in wliicb the (: s*ts on her eggs, and leaves only a small orifice t)lisi"^U which be feeds her; she is thus kept a close f.| j1' r during the whole period of incubation;15 yet t^^nbills are not more conspicuously coloured tiegt8ltlany °^ler birds of equal size which build open vi(%' b, is a more serious objection to Mr. Wallace’s Ha](’.as ls admitted by him, that in some few groups the ftt^ S (lre brilliantly coloured and the females obscure, f]i,s \et the latter hatch their eggs in domed nests. Si|p( ^ the case with the Grallime of Australia, the tll6 Warblers (Maluridae) of the same country, A^'^irds (Nectarinim), and with several of the Indian Honey-suckers or Meliphagidas.16
? ^°ok to the birds of England wrn shall see that
j 18 no close and general relation between the %, S the female and the nature of the nest con- dn.jj W by her. About forty of our British birds (ex- A those of large size which could defend them- V/ JU‘bt in holes in banks, rocks, or trees, or con- ('°nied nests. If we take the colours of the Of goldfinch, bullfinch, or blackbird, as a standard 'Wrrl ^e8ree of conspicuousness, which is not highly
H
dbe sitting female, then out of the above u'ds, the females of only twelve can be considered
c >' t
^PPcify, as instances of obscureiy-colotirod birds building
., -riK. ,, tiie species belonging to eight Australian genera,
k'fibj.j . tiie species belonging to eight Australian genera, jhfl, ("Onhl's ‘ Handbook of the Birds of Australia,’ vol. i.
tr. ■ 244-
j’ardn 365’.383, 3S7, 389, 391, 414.
‘h* ti"’ '.^'rds of India,’ vol. i. p. 5 b'ldljQ ® Utdihcation and colours of these latter species, sec Gould s b &o-, vol. i. p. 504, 527.
170
SEXUAL SELECTION: BIKDS.
PAS*'
as conspicuous to a dangerous degree, the reiual twenty-eight being inconspicuous.17 Nor is there
ii>
— x - ip
close relation between a well-pronounced differcD(1 , ,
e of1
colour between the two sexes, and the nature 01 ,
nest constructed. Thus the male house-sparrow (/ u domestieus ) differs much from the female, the ^ trce-spurrow (P. montanus) differs hardly at all, both build well-concealed nests. The two sexes ol ^ common fly-catcher (Muscicapa c/risola) can Jiard-I} distinguished, whilst the sexes of the pied fly-c*1^, (M. luduosa) differ considerably, and both build in llP,jl, The female blackbird ( Turdus merula) differs the female ring-ouzel (T. iorquatus) differs and the female common thrush (T. mmicus ) at all from their respective males ; yet all build nests. On the other hand, the not very ^
allied water-ouzel ( Ginclus aquaticus) builds a nest, and the sexes differ about as much as in tbe p p ol the ring-ouzel. The black and red grouse j|- tetrix and T. Scoticus ) build open nests, in equally concealed spots, but in the one species the sexes 1 greatly, and in the other very little.
Notwithstanding the foregoing objections, I doubt, after reading Mr. Wallace’s excellent esS
17 1 lmve consulted, mi this subject, Macgillivray’s ‘ liri* 'd’ t0 i;|1' and though doubts may be entertained in some cases in reg911 ,|C: degree of concealment of the nest, and of the degree of couspicll,°l[)Ii]<'i of the female, yet the following birds, which all lay their- egg9 1,1 or in domed ne»ls, can hardly he consider! d, according to ft* d1 standard, as conspicuous : Passer, 2 species; Sturnus, of 'dj'hcifj female is considerably less brilliant than the male; Cinelusi W’V y boarula (?) ; Eiithm-ns (?) ; Fruticohi, 2 sp.; Saxicola; sp, ; Sylvia., a sp. ; Parus, 3 sp. ; Meristura; Anurthura; 1 ' ft1 Sitta; Yunx; Muscicapa, 2 sp. ; Hirundo, 3 sp.; and C-ypse111^#^ females ot the following 12 birds may be considered as cowl according to the same standard, viz., Pastor, Motacilla alb^v^y* major and P. cseruleus, Upupa, Pious, 4 sp., Coracias, Alcedo, »n“ 1
COLOUR AND NIDIFICATION.
171
V
xv.
St 0f the
poking to the birds of the world, a large majority c0|0 'e sPecies in which tlio females are conspicuously iif(. (and in this case the males with rare exceptions -h];% conspicuous), build concealed nests for the 1 protection. Mr. Wallace enumerates18 a long
O0[
S*of‘
Vj]j ' ut groups in which this rule holds good ; but it ,nUHlCe her« to give, as instances, the more familiar
kt
>of
kingfishers, toucans, trogous, puff-birds (Capi-
UJJ-jj 1 lit
Patt S’ PSn tain-eaters (Musoplmgse), woodpeckers, and °ts- Mr. Wallace believes that in these groups,
‘the
tiijjj ' ^ales gradually acquired through sexual selec- ts ^ eir brilliant colours, these were transferred to hit] '"'"(des and were not eliminated by natural selec- to the protection which they already enjoyed
S\v \.eir manner of nidification.
ifot6
According to this
^ Sr present manner of nesting was acquired their present colours. But it seems to me Bl0l'e probable that in most cases as the females {^gradually rendered more and more brilliant from % j of the colours of the male, they were gradu- °>ioj ' , to change their instincts (supposing that they
built open nests), and to seek protection by
tof,
domed or concealed nests. No one who studies, VrC6’ Audubon’s account of the differences in the VteJ u^e same species in the Northern and Southern V, t| States,19 will feel any great difficulty in adrnit- birds, either by a cliauge (in the strict sense Sey word) of their habits, or through the natural
variations of
%ct M so-called spontaneous
m-
readily be led to modify their manner of
S i, 11111 of Travel/ edited by A. Murray, vol. i. p. 78.
t, tl>
Si,
l'! eiH'ic'lU^ sla*,el«euts in the ‘ Ornithological Biography.’ See, also, Si,jn'j“ observations on tlie nests of Italian birds by Eugenio ‘ Atti della Socicta Italiftna,’ vol. xi. 18G9, p. 487.
172
SEXUAL SELECTION : BIRDS.
nr
This way of viewing the relation, as far as it good, between the bright colours of female birds ^ their manner of nesting, receives some support ^ certain analogous cases occurring in the Sahara Here, as in most other deserts, various birds, and & „ other animals, have had their colours adapted in a ^ derful maimer to the tints of the surrounding sU‘it,v, Nevertheless there are, as I am informed by the hh Mr. Tristram, some curious exceptions to the rule! ’ ; the male ol the Monticola cyanea is conspicuous ^ his bright blue colour, and the female almost conspicuous from her mottled brown and white piot,I%-
r i ; 1> t\ i p _ v
(it/
, "• CUO HU 11U1U »- sI]|"
protection from their colours, yet they are ablet^ vive, for they have acquired the habit, when in
both sexes of tuo species of Dromolsea are of a black ; so that these three birds are far from r<;CCl'
' j — x — — '*VJ
of taking refuge in holes or crevices in the rocks* With respect to the above-specified groups of ^ in which the females are conspicuously coloured . build concealed nests, it is not necessary to that each separate species had its nidifying ft specially modified ; but only that the early prOge,ij of each group were gradually led to build d 0&el j,,. concealed nests; and afterwards transmitted stinct, together with their bright colours, to their 11 [,, fied descendants. This conclusion, as far as it trusted, is interesting, namely, that sexual together with equal or nearly equal inheritance b' . jjjr sexes, have indirectly determined the manner °f ,l) cation of whole groups of birds. ^
Even in the groups in which, according to M1.' ^ lace, the females from being protected during tion, have not had their bright colours :i
through natural selection, the males often difl'er^./ slight, and occasionally in a considerable degi'ee>
COLOUR AND NIDIFICATION.
173
'Up. V
XV.
^6 r
e^e, l^es' This is a significant fact, for sucli differ- of S(jS colour must be accounted for on the principle
°f the variations in the males having been from % ^mited in their transmission to the same sex ;
hardly be maintained that these dihercnces, C^hy when very slight, serve as a protection to of J}'uaie. Thus all the species in the splendid group %i,te .Jr°g°ns build in holes; and Mr. Gould gives ° °f both sexes of twenty-five species, in all of <h 'vdh one partial exception, the sexes differ some- th. Rightly, sometimes conspicuously, in colour, t|)0(i ‘j'cs being always more beautiful than the iemalcs, the latter are likewise beautiful. All the tlm e® °f kingfisher build in holes, and with most of llt Sheeieg the sexes are equally brilliant, and thus tar 1%^ Place’s rule holds good ; but in some ot the a'’au species the colours ot the females are rather than those of the male ; and in one splen- tliviy 0(Jtoured species, the sexes differ so much that llf_ *ere at first thought to be specifically distinct.'^' gf0|J ' lb Sharpe, who has especially studied this in l1’ tas shewn me some American species (Ceryle) bl^. ict the breast of the male is belted with Again, in Carcineutes, the difference between . es is conspicuous: in the male the upper sur- ^eii)c>S ^AU-blne banded with black, the lower surface P^tly fawn-coloured, and there is much red >Mai tAe head; in the female the upper surface is Hite . 0Wn banded with black, and the lower surface Hs ^ "ith black markings. It is an interesting fact, l6"ing l10w ti,e same peculiar style ol sexual
!» s
*> V\*
t Xan, l-|S ‘ Monograph of the Trogonidas,’ first edition.
eb Cyanalcyon. Gould’s • Handbook of the Birds of Aus- ° p. 133 ; see, also, p. 130, 136.
174
SEXUAL SELECTION: BIRDS.
pi®1
colouring often characterises allied forms, that in species of Ducelo the male differs from the fem
tl/
ale
(iJ
;
in the tail being dull-blue banded with black,
that of the female is brown with blackish bars; s° here the tail differs in colour in the two sexes in c*8/, the same manner as the whole upper surface k* sexes of Carcineutes.
, W
With parrots, which likewise build in holes,
we1
analogous cases: in most of the species both brilliantly coloured and undistinguishable, but ifl/.ijj few species (he males are coloured rather more W than the females, or even very differently from ^ Thus, besides other strongly-marked differences; ,
- -■ -osit^
¥
$
whole under surface of the male King Lory (Ap scapulatus) is scarlet, whilst the throat and chest A female is green tinged with red : in the EupheffM dida there is a similar difference, the face and coverts moreover of the female being of a ]«d°r , A than in the male.22 In the family of the tits which build concealed nests, the female of our c°f blue tomtit ( Pants c/eruleus) is “ much less hr ^ < coloured” than the male; and in the magnificent ^ll yellow tit of India the difference is greater.23 jjif
Again in the great group of the woodpeckers, sexes are generally nearly alike, but in the 2neus validus all those parts of the head, neck, breast, which are crimson in the male are pal® ^ of in the female. As in several woodpeckers the h(>1^ |: the male is bright crimson, whilst that of the fm#
22 Every gradation of difference between the
sexes may
be
the parrots of Australia. See Gould's 4 Handbook/ &c., vol. ii* P* 1 33 Macgillivruy’s 4 British Birds,’ vol. ii. p. 433. Jerdon,
India/ vol. ii. p. 282.
24 All the following facts are taken from M. Malherbe’s ‘ Monographic des Piciddes,’ 1861.
COLOUR AND NIDIFICATION.
175
%
Xv.
Maj
it
occurred to me that this colour might possibly
* le female dangerously conspicuous, whenever ' 1 her head out of the hole containing her nest, h?'lsefluently that this colour, in accordance with face’s belief, had been eliminated. This view is *■**'«■* by what Malherbe states with respect to like q|U8 carlotta; namely, that the young females, ® young males, have some crimson about their ^1* ;V|f that this colour disappears in the adult ^ intensified in the adult male. Nevcr- following considerations render this view feculj. - doubtful: the male takes a fair share in V"l0D,25 and would be thus far almost equally ,||(dr 6r
^ danger ; both sexes of many species have 'i^; lea^s of an equally bright crimson ; in other
fl -i .
° ^ai‘l 6 c ^erence between the sexes in the amount M'fftej 80 that it can hardly make any
difference in the danger incurred ; and
^tty tl
diff co^ou™e °f t'10 head in the two
sexes
1’ile“uers slightly in other ways.
as yet given, of slight and graduated
the"'''
1,1 a lLes in colour between the males and females
ill
^likl ^r°uPs, iu which as a general rule the sexes 6 6ac^ otdior, all relate to species which build ^"ij,'1' coaceafe(l nests. But similar gradations may ^ a ^ observed in groups in whieb the sexes ' ^r‘ a 6ra^ rufe resemble each other, but which build Hr0(g sts- As I have before instanced the Australian ■his ' , i ° ^ may here instance, without giving any *Hee le Australian pigeons.26 It deserves especial at in all these cases the slight differences in
«,**> Vof ;°U 8 ‘ Ornithological Biography,’ vol. ii. p. 75 ; see also the
bald’s J'b268-
Handbook of the Birds of Australia,’ vol. ii. p. 109-149.
176
SEXUAL SELECTION: BIRDS.
pA
jK'
plumage between the sexes are of the nature as the occasionally greater differences. - . illustration of this fact has already been afford131
same
‘ p V
those kingfishers in which either the tail a!t"'>
in
aloo*
the whole upper surface of the plumage differs >- |, same manner in the two sexes. Simiiar cases i)ill',i!i observed with parrots and pigeons
The differ00^
x jijr
colour between the sexes of the same species are^pii!
of the same general nature as the differences iu
between the distinct species of the same group
VX UiiV CUIlUVy rj
when in a group in which the sexes are usually the male differs considerably from the female, A
not coloured in a quite new style. Hence
infer that within the same group the special coIou'V
of
both sexes when they are alike, and the colours male, when he differs slightly or even consider»Hv ' the female, have in most cases been determined ^
abW*’
same general cause ; this being sexual selection-
It is not probable, as has already been
.. w*-' x»x»o WHOMLiy UCWU -
that differences in colour between the sexes, whe*
jj-i ivimu PJCtutCll tilt? (SCACoj rr
slight, can be of service to the female as a pr°te<jj!vlil Assuming, however, that they are of service, they Jll ,p0
A.1 Lx X , - . ... ... ,
be thought to he cases of transition; but we
- - » — tin
reason to believe that many species at any 0,)'
are undergoing
change.
Therefore we can
it<;
<6
admit that the numerous females which di$e* ^ slightly in colour from their males are now ;d meucing to become obscure for the sake of p1'0^ $
Lven it we consider somewhat more marked seS!l'()('tl|1'
-1* ,,v wxioiu«i- Bwmewnai more manceu ferermes, is it probable, for instance, that the bea1 ^ female chaffinch, the crimson on the breast of tbe jb
bullfinch,— the green of the female greenfincjO “ ' ’ »n • '
¥
crest of the female golden-crested wren, have - . ^ ,» rendered less bright by the slow process of select!‘- the sake of protection ? I cannot think so ; and
COLOUR ASD NIDIFICATION.
177
'**». y
Sv.
bircjs le slight differences between tlie sexes of those the w!licli build concealed nests. On the other hand, greai' 6l'onces in colour between the sexes, whether On ^ ot small, may to a large extent be explained by tj'" Principle of the successive variations, acquired Sn tL 111 nles through sexual selection, having been to i] 16 rirst more or less limited in their transmission ^etriales. That the degree of limitation should ettrp,,;10 different species of the same group will not *ot y aily one who has studied the laws of inheritance, iga0l, are so complex that they appear to us in our 48a,Uce to be capricious in their action.37 °f as I can discover there are very few groups ri \vj ,s c°ntaining a considerable number of species, ‘!.' h nil have both sexes brilliantly coloured 1 at ’ ^ut this appears to be the case, as I hear , Sclater, with the Musophagm or plain- ■ ers‘ Nor do I believe that any large group
<^si ’a "bicli the sexes of all the species are widely
% Ullilnr
Nte 1,
• ■ best
tbe |^a^®rers of S. America ( Cotingidee ) offer one of Hint. lnstances : but with some of the species, in
m colour: Mr. Wallace informs me that
hcjj . j 1Ustances ;
p, ° ma^e bas a splendid red breast, the female <% " Sl»«e red on her breast; and the females of °f th6S^ecies 8bew traces of the green and other colours to lll;dos. Nevertheless we have a near approach
rio.
i<fiVetal S°Xlla' similarity or dissimilarity throughout thP §lcmP8 : and this, from what has just been said *W b'ctuatin
^‘'Prising sbould SurPrisin
6 nature of inheritance, is a some- circumstance. But that the same largely prevail with allied animals is
The domestic fowl has produced a
P°V ***» to this effect in my work on ‘ Variation under Pomes-
',0li j ‘ ll- chap. xii.
N
178
SEXUAL SELECTION: BIEDS.
PAR!1
great number of breeds and sub-breeds, and in
tbese
~ MS
tbe sexes generally differ in plumage; so that n . been noticed as a remarkable circumstance wheB ^ certain sub-breeds they resemble each other. On j other hand, the domestic pigeon has likewise prodn^ a vast number of distinct breeds and sub-breeds* ^ in these, with rare exceptions, the two sexes are ide” j cally alike. Therefore if other species of Gallns a Columba were domesticated and varied, it would no1 j rash to predict that the same general rules of seXl^{ similarity and dissimilarity, depending on the for®® ,, transmission, would, in both cases, hold good. ^ similar maner the same form of transmission has ge rally prevailed throughout the same natural although marked exceptions to this rule occur, d 1 ^ the same family or even genus, the sexes naif identically alike or very different in colour. Inst^0 have already been given relating to the same geI as with sparrows, fly-catchers, thrushes and grouse- , the family of pheasants the males and females of all the species are wonderfully dissimilar, but are similar in the eared pheasant or Crossopiilon aui'1 ^ In two species of Chloephaga, a genus of geese,
males cannot be distinguished from the females, e> p by size; whilst in two others, the sexes are so uly s*. that they might easily be mistaken for distinct s]>eCl<^jie, The laws of inheritance can alone account ^ following cases, in which the female by acquiri11^^ a late period ol life certain characters proper to ^ male, ultimately comes to resemble him in a jjy less complete manner. Here protection can l^.'t have come into play. Mr. Blyth informs »ie the females of Oriolus melanoceplialus and of
28 The ‘Ibis,’ vol. vi. 1S61, p. 122.
COLOUR AXD NIDIFICATION.
179
Ap,
XV.
species, when sufficiently mature to breed, differ ’ably in plumage from the adult males ; but
alHed
c°Usid
^ e.1' ^le second or third moults they differ only in div'1' ^ea^s having a slight greenish tinge. In the „ bitterns (Ardetta), according to the same au- “the male acquires his final livery at the
' first
moult, the female not before the third or fourth
a ; in the meanwhile she presents an iuter- i, )ediate garb, which is ultimately exchanged for the f livery as that of the male.” So again the le Falco peregrinm acquires her blue plumage te slowly than the male. Mr. Swinhoe states that
Mth
0lle of the Drongo shrikes (Dicrurus maerocercus )
moults his soft
the v,
l male whilst almost a nestling.
g,, | plumage and becomes of a uniform glossy
ilih llls^"black ; but the female retains for a longtime %d V'^e sfn8e and spots on the axillary feathers; o0| not completely assume the uniform black e^01’1’ °f the male for the first three years. The same Sec en^ observer remarks that in the spring of the Jll(l year the female spoonbill (Platalea) of China re- fes the male of the first year, and that apparently u°t until the third spring that she acquires the adult plumage as that possessed by the male at a
as
djjjf'1 ea,her age. The female Bombycilla caroUnensis Hi's Vei'y little from the male, but the appendages, W hke beads of red sealing-wax ornament the wing-
rers _
•i]
flip 7 J1"8> are not developed in her so early in life as in
The upper mandible in the male of an Indian eatp fi:eef ( Palseornis Javanicus ) is coral-red from his youth, but in the female, as Mr. Blyth has
cl lest
°oserv j . - ^
j <;c with, caged and wild birds, it is at first black
olt, a°°s not become red until the bird is at least a year Cs’ 'vhich age the sexes resemble each other in all ' s- Both sexes of the wild turkey are ultimately
x 2
ISO
SEXUAL SELECTION: BIEDS.
Part 1
in
furnished with a tuft of bristles on the breast, bid ^ two-year-old birds the tuft is about four inches lou? the male and hardly apparent in the female; however, the latter has reached her fourth year, from four to five inches in length.29
In these cases, the females follow a normal courS®
it’5
.a
development in ultimately becoming like the males ; iU’, such cases must not be confounded with those in , diseased or old females assume masculine charad® . or with those in which perfectly fertile females,"'^1 ", young, acquire through variation or some unknown the characters of the male.30 But all these cases so much in common that they depend, according t° ..
hypothesis of pangenesis, on genumdes derived from eil‘
part of the male being present, though latent, in the male ; their development following on some slight elm11' in the elective affinities of her constituent tissues.
A few words must be added on changes of pin11”1', in relation to the season of the year. From red® formerly assigned there can be little doubt that ^ elegant plumes, long pendant feathers, crests, egrets, herons, and many other birds, which are loped and retained only during the summer, ge ^ exclusively for ornamental or nuptial purposes, th°l1'
ft
-IJ On Ardetta, Translation of Cuvier s 1 Iiiigne Animal,’ by Mr- footnote, p. 15‘J. On the Peregrine Falcon, Mr. Blyth, in ^ _ e worth’s 1 Mag. of Nat. Hist,.’ Vol. i. 1837, p. 30h On Bicrurus, tliC
18(13, p. 44. On the Platalea, ‘Ibis,’ vol. vi. 1864, p. 366. u pH Bombycilla, Audubon’s ‘ Oruitholog. Biography,’ vol. i. p. the PaJioornis, see, also, Jerdon, • Birds of India,’ vol. i- 1’’ V On the wild turkey, Audubon, find. vol. i. p. 15: 1 hear from 1
i. p.
Caton that iu Illinois the female very rarely acquires a tuft. 30 Mr. Blyth has recorded (Translation of Cuvier’s
Ifegue A» #
p. 158) various instances with Lanius, Buticilla, I, inaria, and 1 ^ Audubon has also recorded a similar case (‘ Ornith. Biog.’ vol. v’’ P‘ with Tymnga mstiva.
SUMMER PLUMAGE.
181
LHiP.
XV.
The female is thus rendered
to both sexes, a® conspicuous during the period of incubation than nS the winter ; but such birds as herons and egrets pi 1 be able to defend themselves. As, however, of lQes would probably be inconvenient and certainly ]lftp0 use during the winter, it is possible that the °f moulting twice in the year may have been sui Ually acquired through natural selection for the tyj'10 casting off inconvenient ornaments during the 'h?er* ^*’s Vlew canu°t be extended to the many >■ ers> in which the summer and winter plumages
very little in colour. With defenceless species.
%v
either both sexes or the males alone become or leniely conspicuous during the breeding-season, — ,;;^n the males acquire at this season such long n ® 0r tail-feathers as to impede their flight, as with ^ ,lQ6t°ruis and Vidua, — it certainly at first appears fojf 1 y Probable that the second moult has been gained flie special purpose of throwing off these ornaments. Pi^ust, however, remember that many birds, such as
‘>ot
\y le special purpose of throwing
. uust, however, remember tha — ,
8 °f Paradise, the Argus pheasant and peacock, do W !l ^lel'r P^umes during the winter ; and it can . *,e maintained that there is something in the iwfltution of these birds, at least of the Gallinaceae,
'^Uerin... „ u : f at... • . ...
Vts H
er»ng a double moult impossible, for the ptarmigan ts thrice in the year.31 Hence it must be eon- O* as doubtful whether the many species which 1 1 their ornamental plumes or lose their bright ^ during the winter, have acquired this habit on t^j ni,|t of the inconvenience or danger which they would j6lwise have suffered.
(;°n elude, therefore, that the habit of moulting
the year was in most or all cases first acquired
31 See Gould’s ‘Birds of Great Britain.’
382
SEXUAL SELECTION: BIEDS.
pABT 1
for some distinct purpose, perhaps for gaining a wart0^ winter covering ; and that variations in tiie plum®^ occurring during the summer were accumulated throt'r sexual selection, and transmitted to the offspring at 1 1 same season of the year. Such variations being ritecl either by both sexes or by the males alone, ace1’’1., ing to the form of inheritance which prevailed. " jj appears more probable tbap that these species i» !lj cases originally tended to retain their ornames11! plumage during the winter, but wrere saved from m1 through natural selection, owing to the iueonvenieJl or danger thus caused.
I have endeavoured in this chapter to shew that j arguments are not trustworthy in favour of the
tl»«
vie"'
that weapons, bright colours, and various ornamen ' are now confined to the males owing to the convert1 j by means of natural selection, of a tendency to the transmission of characters to both sexes into transJlU f sion to the male sex alone. It is also doubtful 'yrb^]e the colours of many female birds are due to the preS.ejj vation, for the sake of protection, of variations w’b1® were from the first limited in their transmission * , temale sex. But it will be convenient to defer further discussion on this subject until I treat, m ^ following chapter, on the differences in plumage betw£,e the young and old.
INHERITANCE, LIMITED BY AGE.
183
Ci,
Ap- XVI.
CHAPTER XYI.
Birds — concluded.
'^mature plumage in relation to the character of the pi uniage lri both sexes when adult — Six classes of cases — Sexual differ- eDces between the males of closcdy-nllied or representative species ~~ Pie female assuming the characters of the male — Plumage of 16 young in relation to the summer and winter plumage of the adults — On the increase of beauty in the Birds of the World — r°tecti vo colouring — Conspicuously-coloured birds — Novelty appreciated — Summary of the four chapters on Birds.
^ 13 'Rust now consider the transmission of characters •|S| Suited by age in reference to sexual selection.
. 16 truth and importance of the principle of inheri- ts Ce ^responding ages need not here be discussed,
. (;tl0,igh has already been said on the subject. Before f, ' lug the several rather complex rules or classes of l‘ast's> under which all the differences in plumage
H:t'veen tpe youn~ an(j p)ie 0ld, as far as known to
*he, J °
!> joay be included, it will be well to make a few
eVinary remarks.
" ith animals of all kinds when the young differ in °Ur from the adults, and the colours of the former
are
far as we can see, of any special service, they a-v generally be attributed, like various embryological
f pictures, to the retention by the young of the character au early progenitor. But this view can be maintained C| confidence, only when the young of several species ot°8ely resemble each other, and likewise resemble Ij. er adult species belonging to the same group; for {] ? Matter are the living proofs that such a state ol ltlgs was formerly possible. Young lions and pumas
1 84
SEXUAL selection: bieds.
Part Jl‘
are marked with feeble stripes or rows of spots, and l1 many allied species both young and old are simhftr^ marked, no naturalist, who believes in the grad©1 evolution of species, will doubt that the progenitor 0 the lion and puma was a striped animal, the ytd having retained vestiges of the stripes, like the kitteb* of black cats, which when grown up are not in the l®aS striped. Many species of deer, which when mature a11 not spotted, are whilst young covered with white spo(A as are likewise some few species in their adult st»^' So again the young in the whole family of pigs (Said and in certain rather distantly-allied animals, such the tapir, are marked with dark longitudinal strips ' but here we have a character apparently derived fro'1' an extinct progenitor, and now preserved by the ycd alone. In all such cases the old have had their cold changed in the course of time, whilst the young h!lV'j remained but little altered, and this has been efhd through the principle of inheritance at correspond ages.
Tliis same principle applies to many birds belong1®- to various groups, in which the young closely resetf^ each other, and differ much from their respective ad'1 parents. The young of almost all the G allinace©, 0p of some distantly-allied birds such as ostriches, 111 ^ whilst covered with down longitudinally striped ; ^ this character points back to a state of things so *e. mote that it hardly concerns us. Young cross-!'1 (Loxia) have at first straight beaks like those of finches, and iu their immature striated plumage 1111 j| resemble the mature redpole aud female siskin, as " e ^ as the young of the goldfinch, greenfinch, and so"^, other allied species. The young of many kinds ® buntings (Emberiza) resemble each other, and d wise the adult state of the common bunting, E- d
'»Af
'• XVI.
INHERITANCE, LIMITED BY AGE.
385
tlje * a™ost the whole large group of thrushes 'V'lii |'r°Ull» 'iave Lieir breasts spotted — a character
ls retained by many species throughout life, to,,.- ls I'd to lost by others, as by the Tardus migra-
the
0^ 18 a
’ lils- So again with many thrushes, the feathers on acL are mottled before they are moulted for the ^rt, ■' lll'e’ aud this character is retained for life by
fji. 111 eastern species. The young of many species of
U'Ufr-- - • - - --
pj es (Lanins), of some woodpeckers, and of an Indian 6rf ( Chalcophaps Indicus), are transversely striped 10 under surface ; and certain allied species or
Ag*.
c;!f !'a when adult are similarly marked. In some Co,. ' y'aUied and resplendent Indian cuckoos (Cliry, so- ft.0i^x)> the species when mature differ considerably tin,, other in colour, but the young cannot be dis- D^'tshed. The young of an Indian goose ( Sarkidiornk ,n°notus) closely resemble in plumage an allied 1, s> I)endrocygna, when mature.1 Similar facts will l*Wh tSr ^’ven *n regard to certain herons. Young grouse (Tetrad tdrix) resemble the young as well j>fCj 10 °ld of certain other species, for instance the red °r sc°ticus. Finally, as Mr. Llyth, who lias
wDl]ed closely to this subject, has well remarked, the t^i . affinities of many species are best exhibited in a.(] "Umature plumage ; aud as the true affinities of Oganic beiugs depend on their descent from a
^lief
the former"
progenitor, this remark strongly confirms the that the immature plumage approximately shews
or ancestral condition of the species.
L i-i
Vm,e8wd to thrushes, shrikes, and woodpeckers, sec Mr. Blyth, in ‘tis ^'0l'th’s ‘Mag. of Nat. Hist.’ vol. i. 1837, p. 304; also footnote i * L.vj ansktion of Cuvier’s ‘Rtgne Animal,’ p. 159. 1 give the ease ^hith rv*1 ^r> Blythts information. On thrushes, see also Audubon, pt’hi,,,1' d^kgraphy,’ vol. ii. p, 195. On Chrysocoecyx and Ohal- ^0 8#>i- as quoted in Jordon’s ‘Birds of India,’ vol. iii. p. 485. ‘ kdiornis, Blytli, in ‘Ibis,’ 1867, p. 175.
1SG
SEXUAL SELECTION: BIRDS.
Part
Although many young birds belonging to vari°1' orders thus give us a glimpse of the plumage of t>® remote progenitors, yet there are many other birds, dull-coloured and bright-coloured, in which the vo1® closely resemble their parents. With such species }roung of the different species cannot resemble each 0®^ more closely than do the parents ; nor can they Prese']{, striking resemblances to allied forms in their ad'1 state. They give us but little insight into the phi®1?, of their progenitors, excepting in so far that when 1 j young and the old are coloured in the same gen®1 manner throughout a whole group of species, it is Vt0' bable that their progenitors were similarly coloured- We may now consider the classes of cases or rU^ under which the differences and resemblances, bet"’0^. the plumage of the young and the old, of both seSeS. ^ of one sex alone, may be grouped. Eules of this were first enounced bv Cuvier; but with the prOr1’,:. of knowledge they require some modification and a®!’,^ fication. Tin's I have attempted to do, as far ‘ extreme complexity of the subject permits, from ® ^ mation derived from various sources; but a full eS on this subject by some competent ornithologhj { much needed. In order to ascertain to what ^ each rule prevails, I have tabulated the facts giveIJ.,(;j four great works, namely, by Macgillivray on the of Britain, Audubon on those of North America, -T® j on those ol India, and Gould on those of Austral®' ^ may here premise, firstly, that the several cases or ^
jjOi
► * JJ *
raduate into each other ; and secondly, that when to resemble their parents, it
young are
said
meant that they are identically alike, for their
are almost always rather less vivid, and the t’ea are softer and often of a different shape.
CLASSES OE CASES.
187
C«.
*p. \-
XVI.
LULLS OR CLASSES OF CASES.
. - ^ hen tlie adult male is more beautiful or con- iii +jU°.Us ^an the adult female, the young of both sexes lei'r first plumage closely resemble the adult female, all'Vltfi the common fowl and peacock; or, as occasion- tljf 0<?cilrsj they resemble her much more closely than a' the adult male.
ftiFj ’ When ti,e adult female is more conspicuous than y a(^lfit male, as sometimes though rarely occurs, the a lt)" °f both sexes in their first plumage resemble
Vultmale.
W hen the adult male resembles the adult female, ^leir own, as wp;], tl,o robin.
of
young of both sexes have a peculiar first plumage
tllf ‘ When the adidt male resembles the adult female, tjj Wung of both sexes in their first plumage resemble
, — JL
hr.,) adults> ms with the kingfisher, many parrots, crows,
v®
Ner
Se-warblers.
w ’ When the adults of both sexes have a distinct
r aud summer plumage, whether or not the male
04ls froai the female, the young resemble the adults atl* sexes in their winter dress, or much more rarely summer dress, or they resemble the females
it
Niter.
or the young may liave an intermediate cha- in b ' > °r again they may differ greatly from the adults Wt!l their seasonal plumages.
(lilj. ' In some few cases the young in their first plumage ti;ij Irotn each other according to sex; the young s resembling more or less closely the adult males, Nnh'3 females more or less closely the adult
I- — In this class, the young of both sexes file " ^e’ more or less closely, the adult female, whilst afi'dt male differs, often in the most conspicuous
188
SEXUAL SELECTION: BIRDS.
PiHTJ
manner, from the adult female. Innumerable instaDc^ in all Orders could be given ; it will suffice to caU f mind the common pheasant, duck' and house-spa1'1 *'0*! The eases under this class graduate into others. the two sexes when adult may differ so slightlv, and 1 ■ . young so slightly from the adults, that it is doubtf'1 whether such cases ought to come under the present' 0 under the third or fourth classes. So again the y°l!'!;' of both sexes, instead of being quite alike, may in a slight degree from each other, as in our sixth da" These transitional cases, however, are few in nun1^'’ or at least are not strongly pronounced, in compad^ with those which come strictly under the present d®8* The force of the present law is well shewn in , groups, in which, as a general rule, the two sexes ^ the young are all alike; for when the male in ^-ie\ groups does differ from the female, as with certain rots, kingfishers, pigeons, &c., the young of both resemble the adult female * * *.2 We see the same fad e , hibited still more clearly in certain anomalous c®9^, thus the male of HeliotJvrix auriculata (one of the h"’!^ ming-birds) differs conspicuously from the feinal0 * having a splendid gorget and fine ear-tufts, but * j female is remarkable from having a much longe1' ^ than that of the male ; now the young of both
2 for instance, Mr. Gould’s account (*. Handbook of tlie Jj.
Australia, vol. i. p. 133) of Cyanalcyon (one of the Kingfishers) iu '1 1 j,
however, the young male, though resembling the adult femah', 10i,juC
brilliantly coloured. In some species of Duccio the males l«‘r° >
tails, and the females browu ones ; ami Mr. it. B. Sharpe iu,brf Lii'
that the tail of the young male of D. Gaudichaudi is at firs1 11 ,,;;i
Mr. Gould has described (ibid. vol. ii. p. 14, 20, 37) the se*e%.ifl>
the young of certain Black Cockatoos aud of the King Lory . ji. which the same rule prevails. Also Jordon (‘Birds of India,’ vt“' Jje 260) on the Falseornu roea, in which the young are more female than the male. See Audubon (* Ornith. Biograph.’ vol'
475) on the two sexes and the young of Columba passerine
XVI.
THE YOUNG LIKE THE ADULT FEMALES. 189
’’eg.
(with the exception of the breast being spotted 6 leDgth of her tail,
t|1(; i bronze) the adult female in all respects including so that the tail of the male
actual] i
is becomes shorter as he reaches maturity, which * unusual circumstance.3 Again, the plumage spii ° ltJa^e goosander (Margins merganser) is more con- Vyjj. a°Usly colom'ed, with the scapular and secondary .fathers much longer than in the female, but differ- bii/ b°m what occurs, as far as i know, in any other H ! the crest, of the adult male, though broader than
itu °* *be female, is
ktt] 1CU*B1C, is considerably shorter, being only a
k{,iJJ above an inch in length ; the crest of the female bo/ two and a half inches long. Now the young of
&. ,, Sexes resemble in all respects the adult female, that’
r°vver than in the adult male.4
[j V. OG XJ.X IC/J-t/ JllX HI A HJOJ-HJULQ tuc Cl'-t.LiAU
itr ^ b'oir crests are actually of greater length thorn
^ch^en yonng und the females closely resemble vj0(j °ther and both differ from the male, the most ob-
fled.
J*s conclusion is that the male alone has been modi-
-Even in the anomalous cases of the ldeliothrix Iergu8> ^ is probable that originally both adult gw ' *ere furnished, the one species with a much cion-
4 1 ' O Tl /l + h f~\ 4-h .11. 4 1. s-t wt 1 1 r~± 1 nw a "I I
Hi,
and the other with a much elongated crest,
‘Eult °^aracters having since been partially lost byfthe ^‘tt ^a^es fr°m some unexplained cause, and trans- 1U ^buir diminished state to their male offspring Vit ’ "ben arrived at the corresponding age of ma-
hty.
tw.
;0lle ha
f he belief that in the present class the male fce s been modified, as far as the differences be- y(j|l)il the male and the female together with her g are concerned, is strongly supported by some
auj)0 ^'is information to Mr. Gould who shewed mo the specimens ; * Hj ,s ‘ Introduction to the Troehilidse,’ 1801, p. 120.
°SiUivray, ‘Hist. Brit. Birds,’ vol. v. p. 207-211.
190
sexual selection: birds.
p art *
remarkable facts recorded by Mr. Blytli,5 with respef to closely-allied species which represent each othe* 11 distinct countries. For with several of these repi'e8e tative species the adult males have undergone a
ct?r'
tain amount of change and can be distinguished >
ith
females and the young being uudistinguishable, therefore absolutely unchanged. This is the case "-l _ certain Indian chats (Thamnobia), with certain how1' suckers (Ncctarinia), shrikes (Tephrodornis), cert:l|, kingfishers (Tanysiptera), Ivallij pheasants (Gallop1'1' sis), and tree-partridges (Arboricola). .
In some analogous cases, namely with birds hav'J’® a distinct summer and winter plumage, but with ( _ two sexes nearly alike, certain closely-allied spe°fj can easily be distinguished in their summer or n®P^. plumage, yet arc uudistinguishable in their winter well as in their immature plumage. This is the cl'\ with some of the closely-allied Indian wag-tails or ^ cilho. Mr. Swinhoe6 informs me that three specie3'^, Ardeola, a genus of herons, which represent each ot ' »
.rent
hardly, if at all, distinguishable during the winter. ^[e young also of these three species in their f
plumage closely resemble the adults in their 'villt'.,, dress. This case is all the more interesting hecal!jl( with two other species of Ardeola both sexes i'e^, during the winter and summer, nearly the same ph1
a-, (f
5 See llis admirable paper in the < Jouri al of the Asiatic i. Bengal,’ vol. xix. 1850, p. 223; see also Jordon, ‘Birds of India,' ' ^1 introduction, p. xxix. In regard to Tanysiptera, ITof. Schlcg®1,, Mr. Blytli that ho could distinguish several distinct races, comparing the adult males. jolls
0 See also Mr. Swinhoe, in ‘Ibis,’ July, 1883, p. 131 ; and a Preb,;I paper, with an extract from a note by Mr. Blytli, in ‘Ibis,’ J°D' p. 52.
ou separate continents, arc “ most strikingly diffci-e when ornamented with their summer plumes,
C*
;AP. XVI.
the young like the adult females. 191
ctl>Q
tlie il- ™*at possessed, by the three first species during lu*er and in their immature state ; and this plum- dfif 18 common to several distinct species at
ages and seasons, probably shews us liow the ^ gonitor of the genus was coloured. In all these °rir/S’ nilptial plumage which we may assume was jj1(;lUl% acquired by the adult males during the breed- ^ tfeasoa> aucl transmitted to the adults of both sexes tliQ ® oorresponding season, has been modified, whilst , "later and immature plumages have been left un- ified. F °
question naturally arises, how is it that in these t]le Cases the winter plumage of both sexes, aud in ,r6]j 0lIaer cases the plumage of the adult females, as as the immature plumage of the young, have not °vat all affected ? The species which represent each
1 fori
iu distinct countries will almost alwa
U(i^ " ^xoi/ALi^u WUUtUCO YI'J.J.J, tt-JLILlVOli CUvVciyS llciVe
exposed to somewhat different conditions, but we in 'ardly attribute the modification of the plumage f(;i]|r males alone to this action, seeing that the li0j , 68 and the young, though similarly exposed, have Us eea affected. Hardly any fact in nature shews (l;rc °re clearly how subordinate in importance is the WjtliCt action of the conditions of life, in comparison the accumulation through selection of indefinite l0ns> than the surprising difference between the ^ °i many birds; for both sexes must have con- the same food and have been exposed to the ligjj ^imate. Nevertheless we are not precluded from that in the course of time now conditions induce some direct effect; wre see only that this of 0rdinate in importance to the accumulated results Hewecti°m When, however, a species migrates into
teIur C0UntrJr> an(l this must precede the formation of Putative species, the changed conditions to which
192
SEXUAL selection: birds.
Pact i
,0
they will almost always have been exposed will c£,u them to undergo, judging from a widely-spread analog
a certain amount of fluctuating variability. la
0
case sexual selection, which depends on an elei»eI: eminently liable to change — namely the taste or ration of the female— will liave had new shades of coll)l
°d <
sexual selection is always at work, it would (jndg^ from what we know of the results on domestic ani®3^ of man’s unintentional selection), be a surprising fft(jt f
tiy
or other differences to act on and accumulate ; a11*' ,
- 'W
ills
animals inhabiting separate districts, which can cross and thus blend their newly-acquired charac were not, after a sufficient lapse of time, differ611. ) modified. These remarks likewise apply to the nnPfl‘ir or summer plumage, whether confined to the tua!eS
common to botli sexes.
JJi*
4
‘vat013
Although the females of the above closely species, together with their young, differ hardly . from each other, so that the males alone can be dig guished, yet in most cases the females of the spet>3^ within the same genus obviously differ from each ot|11 ^ The differences, however, are rarely as great as bet" ^ the males. We see this clearly in the whole fain''-3, the Gallinaceie : the females, for instance, of the c°
uupiu jjucaotiiiL, ami trsjjtjuijuxy ui tilt*
Amherst pheasant — of the silver pheasant and the fowl — resemble each other very closely in colour
id
ylfi'f
mon and J apan pheasant, and especially of the gold 00 ,
u_, .
the males differ to an extraordinary degree. So ** with the females of most of the Cotingidm, FringH113 ^ and many other families. There can indeed be no do*
DC1
that, as a general rule, the females have been fled to a less extent than the males. Some fe'v
IllO
bP . ,tiop'
however, offer a singular and inexplicable except1" thus the females of Paradisea, apoda and P. Pafl‘\-e differ from each other more than do their respeC
THE YOUNG LIKE THE ADULT FEMALES. 193
C«.
Aj>.
XVI.
the female of the latter species having the
er surface pure white, whilst the female P. apoda is ^eI' °rown beneath. So, again, as I hear from Professor '-"ton, the males of two species of Oxynotus (shrikes), . cu represent each other in the islands of Mauritius k' B°urbon,8 differ hut little in colour, whilst the ^ales differ much. In the Bourbon species the female ( . 1'ears to have partially retained an immature condition . Plumage, for at first sight she “might he taken for ^ e young of the Mauritian species.” These differences 0j.a! be compared with those which occur, independently c ejection by man, and which we cannot explain, in arf ain suh-hreeds of the game-fowl, in which the females t; Very different, whilst the males can hardlv be dis-
Vished.9
(li(fS ^ account so largely by sexual selection for the tl) eie.aces between the males of allied species, howr can • differences between the females be accounted for n all
%
*<Ia
ordinary cases? We need not here consider the e,es which belong to distinct genera ; for with these,
W
jj'Ptation to different habits of life, and other agencies, have come into play. In regard to the differences
"’ill
^en the females within the same genus, it appears to (ho a^'10sl' certain, after looking through various large ill 1 1 >s> that the chief agent has been the transference, fiif.j1 ®reater or less degree, to the female of the cha- 1^ ]trs acquired by the males through sexual selection. y(.r 19 several British finches, the twro sexes differ either ■ lightly or considerably ; ami if wre compare the
V.h'eS ^ie greeufinch, challinch, goldfinch, hull- > crossbill, sparrow, &e., we shall see that they
* ‘ Tlie Malay Archipelago,’ vol. ii. 1869, p. 394.
‘ e?e secies are described, with coloured figures, by M. F. Pollen,
* 1864, p. 275
v arkt.on of ynimals, Ac., under Domestication,’ vol. i. p. 251. V°^. II. 0
194
SEXUAL SELECTIONS' : BIRDS.
p.MiI 1
differ from each other chiefly in the points in wh’c they partially resemble their respective males ; and * colours of the males may safely be attributed to so*’1*1 selection. With many gallinaceous species the
se.
differ to an extreme degree, as with the peacock, p',e8 sant, and fowl, whilst with other species there has been partial or even complete transference of character fr0l'j the male to the female. The females of the s6ve,‘j species of Polvpleetron exhibit in a dim condition, fll>‘ chiefly on the tail, the splendid ocelli of their n)#1 The female partridge differs from the male only i» ^ red mark on her breast being smaller ; and the fen®*1
wild turkey only in her colours being much duller- the guinea-fowl the two sexes are undistinguish®1
In
bl0.
There is no improbability in the plain, though p liar spotted plumage of this latter bird having acquired through sexual selection by the males, ^ ^ then transmitted to both sexes; for it is not essej tiallv different from the much more beautifully-sp0^ , plumage, characteristic of the males alone of the l"1 gopan pheasants. ^
It should he observed that, in some instances, transference of characters from the male to the e has been effected apparently at a remote period, male having subsequently undergone great c^lilll^ejv without transferring to the female any of his gained characters. For instance, the female at|(l
young ot t ie black-grouse ( Telrao ietrix) rese1'5 pretty closely both sexes and the young of the
grouse i . Scoticus ; and we may consequently 111
descended fi axes were c
the same manner as the red-grouse. As both seX®*
fef
that the black-grouse is descended from some species, of which both sexes were coloured in ve‘\ 0{
this latter species are more plainly barred during breeding-season than at any other time, and as the *
tl>®
i
c„.
AP. XVI. THE YOUJTS LIKE THE ADULT FEMALES. 195
^ers slightly from the female in his more strongly- ^ "flounced red and brown tints,10 we may conclude . his plumage has been, at least to a certain extent, Uenced by sexual selection. If so, we may further ), er that the nearly similar plumage of the female nek-grouse was
feriod. But has s
similarly produced at some former since this period the male black-grouse acquired his tine black plumage, with his forked and hardly-curled tail-feathers ; hut of these characters <il'e has hardly been any transference to tho female, fj®pting that she shews in her tail a trace of the curved
.. ^ e may therefore conclude that the females of dis- °t though allied species have often had their plumage Offered more or less different bv the transference in j ll->us degrees, of characters acquired, both during s^lller and recent times, by the males through sexual i .®eti°n. But it deserves especial attention that hant colours liave been transferred much more uy than other tints. For instance, the male of e red-throated bfuebreast ( Cyanecula suecica) has
a sub-triangular red
tin
j, ri°h blue breast, ineludin
now marks of approximately the same shape
Sn,Ve keen transferred to the female, hut the central Pace
is fulvous instead of red, and is surrounded by ' ^ied instead of blue feathers. The Galliuaeeae offer auy analogous cases ; for none of the species, such as
Pfyw . • .. ^ ^ l ‘r
nnges, quails, guinea-fowls, &c., in which the colours ! plumage have been largely transferred from the to the female, are brilliantly coloured. This is
*the
"'ale
Is exemplified with the pheasants, in which the male ^rally so much more brilliant than the female ; "’ith the Eared and Cheer pheasants (Grossoftilon
10
Macgillivrav, ‘Hist. Brilish Birds,’ vol. i. p. 172-171.
o 2
196
SEXUAL SELECTION: BIliDS.
Part 1
IV
auritum and Pliasianus Wallichii) the two sexes close*- resemble each other and their colours are dull- ^ 6 may go so far as to believe that if any part of plumage in the males of these two pheasants had hce|j brilliantly coloured, this would not have been transfer^
to the females. These facts strongly support
Wallace’s view that with birds which are exposed ® much danger during nidification, the transference 0 bright colours from the male to the female has beCI' checked through natural selection. We must IlD ’ however, forget that another explanation, before gireI'j is possible ; namely, that the males which varied became bright, whilst they were young and >ne* perienced, would have been exposed to much dang** and would generally have been destroyed; the d , and more cautious males, on the other hand, if * j varied in a like manner, would not only have been to survive, but would have been favoured in rivalry with other males. Now variations occur11*’® late in life tend to be transmitted exclusively to * same sex, so that in this case extremely bright would not have beeu transmitted to the females. ^ the other hand, ornaments of a less conspicuous 1;|U ’ such as those possessed by the Eared and Cheer sants, would not have been dangerous, and if they ^ peared during early youth, would generally have h®e transmitted to both sexes.
In addition to the effects of the partial transfer61' of characters from the males to the females, some of t.' , differences between the females of closely-allied sVeCi^‘ may be attributed to the direct or definite actio11 the conditions of life.11 With the males any
o'
sucl>
11 See, on this subject, chap, xxiii. in the ‘Variation of Aninr Plants under Domestication.’
THE YOUNG LIKE THE ADULT FEMALES. 197
<V
Ap.
XVI.
Vli'-11 Wou^ generally have been masked by the Hot 'aUt c°l°nrs gained through sexual selection; but sit'j 8° W'^1 t'le females' Each of the endless diver- j- '.s ju plumage, which we see in our domesticated aHcl S 18 ’ coulse’ * be resuit °i' some definite cause ;
otie Un(^er natural and more uniform conditions, some m 6 i,lnb assuming that it was in no way injurious, would in!,l08t certainly sooner or later prevail. The lree Sa f l'Cr°ssirLg of the many individuals belonging to the 1(3 species would ultimately tend to make any change colour, thus induced, uniform in character, i ° °ne doubts that both sexes of many birds have (l)i^ jlieir colours adapted for the sake of protection ; lria 1( ts possible that the females alone of some species ^ave ^een tlnus modified. Although it would be a 1 <»lt, perhaps an impossible process, as shewn in the
e^apter, to convert through selection one form of lllto -another, there would not be the least in adapting the colours of the female, inde- n centiy of those of the male, to surrounding objects, tl>h the accumulation of variations which were from Ust limited in their transmission to the female sex. hi 6 V!Uaa<->ons were not thus limited, the bright tints of the llia'e W0L1^ be deteriorated or destroyed. Whether eeietnaIes aIone of many sPeciew have been thus 1 cCl<dly modified, is at present very doubtful. I wish follow Mr. Wallace to the lull extent ; for the tion lSS^0n W0UEi remove some difficulties. Any varia- "bicli were of no service to the female as a protec- would be at once obliterated, instead of being lost or jT y by not being selected, or from free intercrossing, it,uj °m being eliminated when transferred to the male J." any way injurious to him. Thus the plumage of W0hi J"ln,ale would be kept constant in character. It
ul(i also
be a relief if we could admit that the obscure
198
SEXUAL SELECTION: BIRDS.
PART
,11.
tints of both sexes of many birds had been acquired ^ preserved for the sake of protection, — for example the hedge-warbler or kitty-wren (Accentor modular is 1111 Troglodytes vulgaris), with respect to which we have 1 sufficient evidence of the action of sexual selecta'1^
We ought, however, to be cautions in concluding
or thlt
the
colours which appear to us dull, are not attractive to females of certain species; we should bear in mind s® . cases as that of the common house-sparrow, in wb11-
,eJ>
the male differs much from the female, but does 1,1 exhibit any bright tints. No one probably will disp1
that many gallinaceous birds which live on the °PL.^ ground have acquired their present colours, at least part, for the sake of protection. We know how well tn • are thus concealed ; we know that ptarmigans, changing from their winter to their summer plum®1" both of which are protective, suffer greatly from bffi of prey. Hut can we believe that the very slight 1 ferences in tints and markings between, for insta® , the female black and red-grouse serve as a protect!® Are partridges, as they are now coloured, better 1 tected than if they had resembled quails? slight differences between the females of the com’11 pheasant, the Japan and golden pheasants, serve protection, or might not their plumages have interchanged with impunity? From v hat Mr- ' ^ lace has observed of the habits of certain gallin®ce^ birds in the East he thinks that such slight differ are beneficial. For myself, I will only say that 1 not convinced. 0p
Formerly when I was inclined to lay much s^reS^eSs the principle of protection, as accounting for the^t bright colours of female birds, it occurred to me im- possibly both sexes and the young might aborig11'1^ have been brightly coloured in an equal degree ,
tl‘«
9
THE YOUNG LIKE THE ADULT FEMALES. 199
•«4P.
XVI.
s
ubsequently, the females from the danger during incubation, and the
m-
*'‘“u6 muuwHiuu, auu me young from being fenced, had been rendered dull as a protection. Hot ^n's v'ew ls not supported by any evidence, and is p P^°bable; for we thus in imagination expose during ,V]'. ' tomes the females and the young to danger, from ti i ^‘as subsequently been necessary to shield their a r, lf*ec^ descendants. VVe have, also, to reduce, through ^ I dual process of selection, the females and the young k 1 lllost exactly the same tints and markings, and to lif'e them to the corresponding sex and period of it is also a somewhat strange tact, on the suppo- (ju°u that the females and the young have partaken
to-
f'Me:
o each stage of the process of modification of a i( 11(iy to be as brightly coloured as the males, that the a, "lf-s have never been rendered dull-coloured without a,,e •>0,iug participating in the same change; for there t; instances, as far as T can discover, of species with the mes dull-coloured and the young bright-coloured. A - . ud exception, however, is offered by the young of cer- Woodpeckers, for they have “the whole upper part ,i J die head
tinged with red,’
which afterwards either
dii,
$
*-• ' '
U*«e. into a mere circular red line in the adults of ^ sexes, or quite disappears in the adult females.12 tlfe 1Ua%, with respect to our present class of cases, V probable view appears to he that successive
tfc),sdd°ns in brightness or in other ornamental cbarac- Ijf !1°Ccuri'ing in the males at a rather late period of
Of
,le h; tk
^ ave alone been preserved ; and that most or all "If !ese variations owing to the late period of life at ^itt * aPPeare£i, have been from the first trans- ed only to the adult male offspring. Any varia- nt ls•Ul^Ub,0n, * Ornith.. Biography,’ vol. i. p. 193. Macgillivray, ‘ Hist. ? r<as»' v°t iii. p. 85. See also the ease before given of Indopicus
200
SEXUAL SELECTION: BIRDS.
Part'
tions in brightness which occurred in the females or "j the young would have been of no service to them, a® would not have been selected ; moreover, if danger0'1 ’ would have been eliminated. Thus the females and ^ young will either have been left unmodified, or, il11
this has much more commonly occurred, will have
partially modified by receiving through transference
the males some of the successive variations. Both
have perhaps been directly acted on by the eondit'fl|P
..... . J - ■
tiH all
r uu uy tut?
of life to which they have long been exposed; but t® females from not being otherwise much modified , best exhibit any such effects. These changes and flJ
- • &r
.W
others will have been kept uniform by the free in , crossing of many individuals. In some cases, esped"' ' w ith ground birds, the females and the young may P°S sibly have been modified, independents of the va^e"' for the sake of protection, so as to have acquired
•no*11
same dull-coloured plumage.
Class II. When the adult female is more conspi^'f ^ than the adult male, the young of hotli sexes in their plumage resemble the adult male. — This class is eX&ct ' the reverse of the last, for the females are here _ brightly coloured or more conspicuous than the va^- ’ and the young, as far as they are known, reset® the adult males instead of the adult females. But t ^ difference between the sexes is never nearly so as occurs with many birds in the first class, and t ^ cases are comparatively rare. Mr. Wallace who fj';“ called attention to the singular relation which eS>Sy between the less bright colours of the males and tl1® performing the duties of incubation, lays great stress this point,13 as a crucial test that obscure colours l"lVt
13 ‘Westminster Review,’ July, 1867, and A. Murray, ‘ J° urDa Travel,’ 1868, p. 83.
C,t.
Ap. XVI.
THE YOUNG LIKE THE ADULT MALES. 201
b,
u acquired for the sake of protection during the j°d of nesting. A different view seems to me more , uable. As the cases are curious and not numerous, ^ill briefly give all that I have been able to find.
1
In
the
^arl
one section of the genus Turnix, quail-like birds, female is invariably larger than the male (being v twice as large in one of the Australian species) j ' this ig an unusual circumstance with the G-allinacese.
^ost of the species the female is more distinctly j. °Ured and brighter than the male,14 but in some » ".species the sexes are alike. In Turnix taigoor of K la the male ,£ wants the black on the throat and neck, the whole tone of the plumage is lighter and less a Pronounced than that of the female.” The female 1 P°ars to be more vociferous, and is certainly much ire pugnacious than the male; so that the females j. not the males are often kept by the natives for ltuig, like game-cocks. As male birds are exposed J the English bird-catchers for a decoy near a trap, ^ order to catch other males by exciting their rivalry, n,,the females of this Turnix are employed in India. i( l,;n thus exposed the females soon begin their “ loud 1( Purring call, which can be heard a long way off, i, 'U|(i any females within ear-shot run rapidly to the TSP°t, and commence fighting with the caged bird.” j'e lllIs way from twelve to twenty birds, all breeding- fjltlales, may be caught in the course of a single The natives assert that the females after laying 8^eir eggS associate in flocks, and leave the males to °u them. There is no reason to doubt the truth ^is assertion, which is supported by some observa-
1^8 0t Australian species, see Gould's ' Handbook,’ Ac., vol. ii. p. AiA . ’ anU 1®®- I'1 the British Museum specimens of the
ill,, ralia^ Plain-wanderer ( Pedionomus torquatus ) may be seen, shevv- * ^milar sexual differences.
■tig. 60. Rbynchffia capensis (from Brehm).
“ coloured than the males.” 10 With all other birds. 111 which the trachea differs in structure in the two
“ Jerdon, ‘ Birds of India,’ yol. iii. p. 596. Mr. Swinhoe, in ‘ JbiS’ 1865, p.542; 1866, p. 131,405.
18 Jerdon, 1 Birds of India,’ vol. iii. p. 677.
202
SEXUAL SELECTION: BIRDS.
Pabt 1
tions made in China by Mr. Swinhoe.15 Mr. Bb'ttl believes, that the young of both sexes resemble ^ adult male.
dhe females of the three species of Painted Snip?* (Rhynchsea) “ are not only larger, but much more rid1 '
XVI.
THE YOUNG LIKE THE ADULT MALES.
203
t],'S Baore developed and complex in the male than in j 'e female ; but in the Bhjnchsea Australis it is simple (11 tije male, whilst in the female it makes four distinct ^Involutions before entering the lungs.1’ The female before of this species has acquired an eminently n^'iiline character. Mr. Blytli ascertained, by exa- ^I'lting many specimens, that the trachea is not con- 8° >1,;ed in either sex of B. Bengalensis, which species 0 closely resembles B, Australis that it can hardly be ,'dii'guiyhed except by its shorter toes. This fact is striking ■ ’ ■
^XUul
instance of the law that secondary
... — characters are often widely different in closely- . . lftd forms; though it is a very rare circumstance letl such differences relate to the female sex. The 'Mlllg of both sexes of li. Bengalensis in their first jl^niage arc said to resemble the mature iuale.lb
l6re is aiso reason to believe that the male undertakes j duty of incubation, for Mr. Swinhoe 19 lound the D '''ales before the close of the summer associated in
Tl,
*-S as occurs with the females of the Turnix
116 females of Phalarojms fulicarivs and P. liyperlo- , ill'e larger, and in their summer pi urnage “more gaily I attired than the males.” But the difference in colour Jt'veen the sexes is far from conspicuous. The male ^()Ue of P.fulicarius undertakes, according to Professor ^ ^strup, the duty of incubation, as is likewise shewn lbe state of his breast-feathers during the breeding- The female of the dotterel plover ( Eudromias h°Y^ellus) is larger than the male, and has the red ^ack tints on the lower surface, the white crescent
more
str 'be breast, and the stripes over the eyes, more 0,Jgly pronounced. The male also takes at least a
is Quid’s ‘ Handbook of the Birds of Australia,’ vol. ii. p. 275. rke Indian Field,’ Sept. 1858, p. 3. 18 1 Ibis,’ 1866, p. 298.
204
SEXUAL SELECTION : BIRDS.
Part'
share in hatching the eggs; hut the female like**? attends to the young.20 I have not been able to (]li' covei whether with these species the young resemble ^ adult males more closely than the adult females ; ^ the comparison is somewhat difficult to make on a ccoU" of the double moult.
Turning now to the Ostrich order: the male of the co & mon cassowary ( Casuarius gcdecUus) would be tho«glj* by any one to be the female, from his smaller size ^ from the appendages and naked skin about his he"1 being much less brightly coloured; and I am infor^' by Mr. Bartlett that in the Zoological Gardens h / certainly the male alone who sits on the eggs and ta1;f care of the young.21 The female is said by Mr. T. ^V' Wood 22 to exhibit during the breeding-season a W0* pugnacious disposition; and her wattles then b ec°,1)C enlarged and more brilliantly coloured. So again female of one of the emus ( Dromceus irroratus) is c°r siderably larger than the male, and she possesses/ s ight top-knot, but is otherwise undistinguishable 1,1 plumage. She appears, however, “to have great<?r power, when angry “or otherwise excited, of erectfr# “hke a turkey-cock, the feathers of her neck ^
Britain Prof w stoteraents’ see Mr- Goulds ‘Birds of
“ Pl0f- Newtou informs me that he has long been convm1^
own observations ami from those of others, that the , e the above-named spedes take either the whole or a large share of/ ^ tUat ‘key ".hew much grLer devo'j towards their young when in danger, than do the females,” So / as he informs me, with Lhmm lappmim and some few other in which the females are larger and have more strongly eon**** colours than the males. J
ii. P’
vol.
i -lo T1 i m t « f °fam fWa]lace> ‘Mhtay Archipelago,’ von IdO) assert that the male and female sit alternately on the egg.’’ Z this assertion, as Mr. Bartlett thinks, may he accounted for W “ female visiting the nest to lay Jier egga.
22 t
The Student,’ April, 1870, p, 124.
THE YOUNG LIKE THE ADULT MALES. 205
"'At. XVI.
ft 1
cc oreast. She is usually the more courageous and «e Silistio. She makes a deep hollow guttural boom, . ( sPecially at night, sounding like a small gong. The <i ti ll e has a slenderer frame and is more docile, with <t J voiee beyond a suppressed hiss when angry, or a itj.j ' '' hie not only performs the whole duty of
U 1 ation, but has to defend the young from their ■i lr er > “ for as soon as she catches sight of her pro- she becomes violently agitated, and notwith- >• ^<Uitling the resistance of the father appears to use ';:r utmost endeavours to destroy them. For months * wards it is unsafe to put the parents together, Ay0 erd quarrels being the inevitable result, in which hem id. e generally comes off conqueror.” 23 So (J||] "hh this emu we have a complete reversal not t!)f? hbc parental and incubating instincts, but of i>ej USUa^ mora^ qualities of the two sexes; the females 'Hi l ® S;tVuge, quarrelsome and noisy, the males gentle ^'‘good. The case is very different with the African 1^1 c*h for the male is somewhat larger than the fe- tfil ® and has finer plumes with more strongly con- dJ ' c°i°urs j nevertheless he undertakes the whole j- °f incubation.21
V,.. 'VlU specify the few other cases known to me, in the female is more conspicuously coloured than l°ule, although nothing is known about their man- incubation. With the carrion-hawk of the Falk-
J6r of
t, Viands ( Milvago leueurus ) I was much surprised Hi] ljy dissection that the individuals, which had "!’r tints strongly pronounced, with the cere and orange-coloured, were the adult females; whilst
•gs
1 1 o i j t tUe excellent account of the habits of this bird under confino-
. Mr- A. W. Bennett, in ‘Land and Water,’ May, IS6S, p. 233.
>> /' delator, on the ineubation of the Struthionea ’ 0, 1863.
' Froc. Zoo.
206
SEXUAL SELECTION: BIRDS.
PAR* 1
those with duller plumage and grey legs were the i|lil e[ or the young. In tin Australian tree-creeper ieris erythrops) the female differs from the null*1 1 ‘•being adorned with beautiful, radiated, rufous u^1' “ ings on the throat, the male having this part d'11^ “plain.” Lastly in an Australian night-jar “the h'111'1^ “always exceeds the male in size and in the brill'tl° g “of her tints; the males, on the other hand, have ^ “ white spots on the primaries more conspicuous u)tl “ in the female.” 25
We thus see that the cases in which female bii'^s !! , more conspicuously coloured than the males, with young in their immature plumage resembling the ad1 males instead of the adult females, as in the preV1°-n class, are not numerous, though they are distribute^ various Orders. The amount of difference, also, the sexes is incomparably less than that which freql,tf occurs in the last class ; so that the cause of the h'f e ence, whatever it may have been, has acted on tb0 males in the present class either less energetically °T^{l persistently than on the males in the last class. ' ^ Wallace believes that the males have had their cd0
I nr the Milvngo, see ‘ Zoology of the Voyage of tho
Birds, I All , p. lt>. For the Clinracteris and night-jar (Eur0®t°P j jl c see Gould s ‘ Hanilbook of the Binla of Australia, ’ vol. i. p. 602 1,1 Tho Now Zealand shield rake ( Tadorna variegatd ) offers a quit0 lous ease . the head ot the female is pure white, and her book 1 jgid th"n that of tho male; the head of the male is of a rich dark l)1. ,,d colour, and his hack is clothed with finely pencilled dnt|L'<1' ^jfd feathers, so that ho may altogether be considered ns tho more 1 ^
of the two. Ilo is larger and more pugnacious than the d'lUt' Ajc; does not sit on the eggs. So that in nil these respects this *1^. comes under our first class of oases ; but Mr. Sclater 0 Pr0°'c tiA Soc.’ I860), p. led) was much surprised to observe that the young screes, when about three months old, resembled in their dark b^pul'1 necks the adult males, instead of the adult females; so that d { t]i0 appear in this case that tho feinalos have been modified, wl11 ’ males and tho young have retained a f, inner state of plumage-
Clljj
U’- XyI' THE YOUNG LIKE THE ADULT MALES. 207
^ndered less conspicuous for the sake of protection I llrie the period of incubation; but the difference Jrriveen the sexes in hardly any of the foregoing cases I Pears sufficiently great for this view to he safely ac- Ph‘d. Xu some of the cases the brighter tints of the male are almost confined to the lower surface, and the les> if thus coloured, would not have been exposed to l^ger whilst sitting on the eggs. It should also he fjD| De in mind that the males are not only in a slight less conspicuously coloured than the females, but B °f les s size, and have less strength. They have, tnore- er> not only acquired the maternal instinct of incuba- J1h hut are less pugnacious and vociferous than the and iu one instance have simpler vocal organs. ■ 1,ls an almost complete transposition of the instincts,
abifo, dis
position, colour, size, and of some points of
^ctnre, has been effected between the two sexes.
-'ow if We might assume that the males in the present
have lost some of that ardour which is usual to c B1,‘ sex, so that thev no longer search eagerly for the
'fodes ; or, if we might assume that the females hr
°PCi
ave
th,
°Die much more numerous than the males — and in c-ase of one Indian Turnix the females are said to be t]'Uu"h more commonly met with than the males”26 — f1' 4 it is not improbable that the females would have n tu to court the males, instead of being courted by ^ 111 • This indeed is the case to a certain extent, with at o'3 b‘t(^a’ as we l|ave seen with the peahen, wild turkey, ji; , . certain kinds of grouse. Taking as our guide the of most male birds, the greater size and strength I'll, -be extraordinary pugnacity of the females of the lllx and Emu, must mean that they endeavour to e away rival females, in order to gain possession of
86 Jerdon, ‘Birds of India,’ vol. iii. p. 5J8.
208
SEXUAL SELECTION: BIRDS.
1’AB1 1
the male ; and on this view, all the facts become cle®t’ for the males would probably be most charmed or c.ted by the females which were the most attractive t0 them by their brighter colours, other ornaments, vocal powers. Sexual selection would then soon d° |,S work, steadily adding to the attractions of the female j the males and the young being left not at all, or 1)11 little modified.
Class III. When the adult male resembles the of1 ^ female, the young of loth sexes have a peculiar first age of their own— In this class both sexes when aclllJ. resemble each other, and differ from the young. I*1!' occurs with many birds of many kinds. The male r°l1"' can hardly be distinguished from the female, but young are widely different with their mottled dus^' olive and brown plumage. The male and female of ^ splendid scarlet Ibis are alike, whilst the young f1' brown ; and the scarlet-colour, though common to ho ^ sexes, is apparently a sexual character, for it is not developed with birds under confinement, in the ^ manner as often occurs in the case of brilliantly c°^ loured male birds. With many species of herons t young differ greatly from the adults, and their su®^ plumage, though common to both sexes, clearly h a nuptial character. Young swans are slate-colo>ire ’ whilst the mature birds are pure white ; but it would v superfluous to give additional instances. These ^ ences between the young and the old apparently , t pend, as in tiie two last classes, on the young h®^|^ retained a former or ancient state of plumage, which . been exchanged for a new plumage by the old of h0^. sexes. When the adults are brightly coloured, we conclude from the remarks just made in relation to i ^ scarlet ibis and to many herons, and from the analog/ ^ the species in the first class, that such colours have heL
THE YOUNG LIKE BOTH ADULTS.
209
j|Up,
XVI.
JJVtfted through sexual selection by the nearly mature j es ’> but that, differently from what occurs in the gt 0 dust classes, the transmission, though limited to the ie age, has not been limited to the same sex. Conse- both sexes when mature resemble each other ^ differ from the young.
/o J’AS‘S ^'|T- When the adult male resembles the adult ~niale, tjie young of both sexes in their first plumage Se>atZe the adults. — In this class the young and the Cob 8 ^oth sexes» whether brilliantly or obscurely °Ured, resemble each other. Such cases are, I think, j 0,6 common than those in the last class. We have * England instances in the kingfisher, some wood- <‘ol erS’ ^le j»y* raagP'e, crow, and many small dull- ^ cured birds, such as the hedge-warbler or kitty-wren. tj'!t the similarity in plumage between the young and . 0 old is never absolutely complete, and graduates away o 0 dissimilarity. Thus the young of some members of kingfisher family are not only less vividly coloured s ai1 the adults, but many of the feathers on the lower 4 ,,aee are edged with brown,27 — a vestige probably of °l'Uier state of the plumage. Frequently in the same j^0,1P of birds, even within the same genus, for instance V( atl Australian genus of parrokeets (Platycercus), the y 1,1,1 g of some species closely resemble, whilst the of other species differ considerably from their a leuts of both sexes, which are alike.28 Both sexes Ct -l'le youuS’ ot" the common jay are closely similar ; (jj 111 the Canada jay ( Perisoreus canadensis ) the young (| so much from their parents that they were formerly S|'l'ibed as distinct species.29
9fthfJ^lo.n’ ‘ Birds of India,' vol. i. p. 222, 228. Gould’s ‘Handbook ’°uld, Ibid. vol. ii. p. 37, *1G, 56.
Sa 1 thirds of Australia,’ vol. i. 124, 130. ss ,'°UW, Ibid. vol. ii. p. 37, -16, 56.
Audubon, ‘ Ornith. Biography,’ vol. ii. p. 55. vOr ~
II.
210
SEXUAL SELECTION: BIRDS.
PAR
rll-
Before proceeding, I may remark that under present and two next classes of cases the tacts are
tl'e
SO
tr O3®
complex, and the conclusions so doubtful, that any - who feels no especial interest in the subject had b^e! pass them over.
The brilliant or conspicuous colours which char^j terise many birds in the present class, can rar^' or never be of service to them as a protect!0® ’ so that thev have probably been gained bv the n 1 : 1 '
’ ’ ’ • - • ' tbe
that
fe-
to vo°1(1
► ^ -r J
through sexual selection, and then transferred to females and the young. It is, however, possible the males may have selected the more attractive males ; and if these transmitted their characters their offspring of both sexes, the same results wo^ follow as from the selection of the more attract1 males by the females. But there is some evidence this contingency has rarely, if ever, occurred in any °r
s
■ — U | U<1 JMIVi"— -
tailed to bo transmitted to both sexes, the fern3^ would have exceeded to a slight degree the ®3^! in beauty. Exactly the reverse occurs under nat®’6’ for in almost every large group, in which the se*e_ generally resemble eacli other, the males of some ^ species are in a slight degi'ee more brightly colo®'1 c than the females, it is again possible that the fe®3 ^ may have selected the more beautiful males, these mfl 1 , having reciprocally selected the more beautiful but it is doubtful whether this double process of
those groups of birds, iu which the sexes are gen®'3 alike ; for if even a few of the successive variations ’’
tion would be likely to occur
------ -*J t/LUU, OWlIlg LU IUD £>'
eagerness of one sex than the other, and whether
der
to the greflt.
ri*
»Jg
would be more efficient than selection on one ■ * ^ . alone. It is, therefore, the most probable view ^ sexual selection has acted, in the present class, 3S ^ as ornamental characters are concerned, iu accords®
THE YOUNG LIKE BOTH ADULTS.
211
c«.
■Ap. XVI.
the general rule throughout the animal king- ^0t,1> that is, on the males ; and that these have Emitted their gradually-acquired colours, either ^ttally or almost equally, to their offspring of both
-Another point is more doubtful, namely, whether the Recessive variations first appeared in the males after j e.v bad become nearly mature, or whilst quite young. ^ either case sexual selection must have acted on e male when he had to compete with rivals for 6 possession of the female ; and in both eases the hracters thus acquired have been transmitted to both |f Xes and aq ageS- }3ut these characters, if acquired J)r the males when adult, may have been transmitted first, to the adults alone, and at some subsequent b^'iod transferred to the young. For it is known that ,, ,'en the law of inheritance at corresponding ages the offspring often inherit characters at an d|lier age than that at which they first appeared ^ dieir parents.30 Cases apparently of this kind have observed with birds in a state of nature. For Stance Mr. Blyth lias seen specimens of Lanius ufu$ and of Colymhus glacial/s which had assumed ' blst young, in a quite anomalous manner, the adult IFunage of their parents.31 Again, the young of the swan (Ci/gnus olor ) do not cast off their dark athers and become white until eighteen months or years old; but Dr. F. Forel has described the case three vigorous young birds, out of a brood of four, 11 eh were born pure white. These young birds were ’ albinoes, as shewn by the colour of their beaks
^0 (». _ ......
^ Variation of Animals and Plants under Domestication, vol. n.
Charlesworth, 1 Mag. of Nat. Hist/ vol. i. 1837, p. 305, 306.
p 2
212
SEXUAL SELECTION: BIRDS.
Part ‘
and legs, which nearly resembled the same parts the adults.32
It may he worth while to illustrate the above tbre® modes by which, in the present class, the two se^1” and the young may have come to resemble each otlif'1'' by the curious case of the genus Passer.33 In ^ house-sparrow (P. domesticus ) the male differs ro«c^ from the ternale and from the young. These resendd® each other, and likewise to a large extent both sexe* and the young of the sparrow of Palestine (P. bracM' daetylm), as well as ot some allied species. We m!l< therefore assume that the female and young of ^e, house-sparrow approximately shew us the plumage the progenitor of the genus. Now with the tree-spart'°"r (P. montanus) both sexes and the young closely resend1'1' the male of the house-sparrow; so that they have 11 been modified in the same manner, and all depart f1'0^1 the typical colouring of their early progenitor. may have been effected by a male ancestor of the tree* sparrow having varied, firstly, when nearly mature, °r’ secondly, whilst quite young, having in either case tra1)S' mitted his modified plumage to the females and &0 young ; or, thirdly, he may have varied when adult ^ transmitted his plumage to both adult sexes, and, to the failure of the law of inheritance at correspond'11^ ages, at some subsequent period to his young.
It is impossible to decide which of these three has generally prevailed throughout the present class 0 cases. The belief that the males varied whilst young’ and transmitted their variations to their offspring 0
32 ‘ Bulletin <te la See. Vaudoise des So. Nat,.’ vol. x. ISGO, !>• ^ The young of the Polish swan, Cygnua immutahilis of Yarrell’ "j always white; but this species, as Mr. Sclater informs me, is b<he' , to be nothing more than a variety of the Domestic Swan (C^««s
33 I am indebted to Mr. Blyth for information in iegard to genus. The sparrow of Palestine belongs to the sub-genus Petrol'
THE YOUNG LIKE BOTH ADULTS.
213
xvi.
<Jt*' sexes is perhaps the most probable. I may here '* that 1 have endeavoured, with little success, bv ^‘suiting various works, to decide how far with birds 16 period of variation has generally determined the 'Emission of characters to one sex or to both. The v° rules, often referred to (namely, that variations °ccurrinor late in life are transmitted to one and the
Sa«ie
sex, whilst those which occur early in life are
|'ansmitted to both sexes), apparently hold good
in
first,34 second, and fourth classes of cases; but lf'6y fail in an equal number, namely, in the third, in the fifth,35 and iu the sixth small class, 'ey hold good, however, as far as I can judge, with a e°Hsiderable majority of the species of birds. Whether °r Hot this be so, we may conclude from the facts j'lv°n in the eighth chapter that the period of variation j,i,s been one important element in determining the 0l'ii of transmission.
^ ith birds it is difficult to decide by what standard Vi,; ought to judge of the earliness or lateness of the j/'iod of variation, whether by the age in reference to 110 duration of life, or to the power of reproduction, 01 to the number of moults through which the species Passes. The moulting of birds, even within the same Hinily, sometimes differs much without any assignable
t[, instance, tlie males of Tanagra estiva and Fringilla cyanea
^ three years, the male of Fringilla ciris four years, to complete |, beautiful plumage. (See Audubon, ‘Ornith. Biography,’ vol. i. j,j 280, 378.) Tlie Harlequin duck takes three years (ibid. vol. J.,/1' ^t4). The male of the Gold pheasant, as I hear from Mr. J. kio'if1 can he distinguished from the female when about three
of ti 18 ollb Hut He does not acquire his full splendour until the end :i5 '® September in the following year, pi jhus the Ibis tantalus and Grus Ameriuanus take four years, the tp _ QS° several years, and the Arclea Ludovicana two years, before V0]>.ac<iuire their perfect plumage. See Audubon, ibid. vol. i. p. 221 ;
' lii- P- 133, 139, 211.
214
SEXUAL SELECTION : BIKDS.
ParJ' ■
cause. Some birds moult so early, that nearly ^ the body-feathers are cast off before the first wing' feathers are fully grown j and we cannot believe th;1| this was the primordial state of things. When the peri°( of moulting has been accelerated, the age at with’1' the colours of the adult plumage were first develops would falsely appear to us to have been earlier it really was. This may be illustrated by the practice followed by some bird-fanciers, who pull out a feathers from the breast of nestling bullfinches, from the head or neck of young gokl-pheasants, order to ascertain their sex ; for in the males tl>eS° feathers are immediately replaced by coloured ones-'’ The actual duration of life is known in but few' birds,®0 that we can hardly judge by this standard. And wi*1’ reference to the period at which the powers of repr°' duction are gained, it is a remarkable fact that vari°°s birds occasionally breed whilst retaining their iinmatur° plumage.37
The fact of birds breeding in their immature plunn'ty seems opposed to the belief that sexual selection bllS
38 Mr. Illy til, in Clmrlesworth’s ‘Mag. of Nut. Hist.’ vol. i. I837’ ,100. Mr. Bartlett lias informed me in regard to gold-pheasants. .
Sl I have noticed the following eases in Audubon’s ‘Ornith- graphy. the lledstart of America’ (Muscicapa rutieilla, vol. *' j 20ii). The Ibis tantalus takes four years to come to full maturity- 0 sometimes breeds in the second year (vol. iii. p. 133 . The (irus re canus takes the same time, but breeds before acquiring its foil (vol. iii. p. 211}. The adults of Arden cterulea are blue and the J'01" ", white; and white, mottled, an.l mature blue birds may all fl,r- breeding together (vol. iv. p. 58, : but Mr. Blytb informs me the* CA tain lierons apparently are dimorphic, for wliite and coloured iiulivR 11 of the same age may be observed. The Harlequin duck j, u
trionica, Tanu.) takes three years to acquire its full plumage, tfo’1.',, many birds breed in the second year (vol. iii. p. 611). Th" " ‘j.,, headed Eagle ( Falco leucocephalus, vol. iii. p. 210) is lik6'lr known to breed in its immature state. Some species of Oriol»s ^ cording to Mr. Blyth and Mr. Swinhoe, in ‘Ibis,’ July, 1863, P- likewise breed before they attain their full plumage.
THE YOUNG LIKE BOTH ADULTS.
215
Ciu
AP. XVI.
^;ayed as important a part, as I believe it has, in Mviiig ornamental colours, plumes, &c., to the males, by means ot' equal transmission, to the iemales of ''lany species. The objection would be a valid one, if younger and less ornamented males were as sue- ^Ssiul in winning females and propagating their kind, Hie older and more beautiful males. But we have 1,0 reason to suppose that this is the case. Audubon ^Peaks of the breeding of the immature males of Ibis lllltalug as a rare event, as does Mr. Svvinhoe, in re- h'tl'd to the immature males of Oriolus.38 If the young any species in their immature plumage were more 8l,ecessful in winning partners than the adults, the ilt,l|lt plumage would probably soon be lost, as the Joules which retained their immature dress ior the ''''Rest period would prevail, and thus the character ot e species would ultimately be modified.39 If, on the
g a
young never succee-
ded in obtaiuin
j!tller hand, the _
|l'rriJde, the habit of early reproduction would perhaps Sooner or later quite eliminated, from being super* "r°tis and entailing waste of power.
L'he plumage of certain birds goes on increasing in
'39 ^ee *'je l0** foot-note.
i . Other animals, belonging to quite distinct classes, are either 0ii J'taally or occasionally capable of breeding before they have fully .'j'Ured their adult characters. This is the case with the young ;°3 of the salmon. Several amphibians have been known to breed
'“Hi,
Hil
;i st retaining their larval strueturo. Fritz Midler has shewn (‘ Facts -S|9 -Arguments for Darwin,’ Eng. Irons. 1.869, p. 79) that the males of u umphipod crustaceans become Sexually mature whilst young; ' 1 infer that this is a case of premature breeding, because they
&'e hot ns yet acquired their fully-developed claspcrs. All such facts highly interesting, as hearing on one means liy which sptcies may
Vj ' orSo great modifications of character, in accordance with Mr. Cope’, dr "s’ expressed under the terms of the “ retardation and ucceleratloi generic characters but I cannot follow die views of this eminen [fr "'alist to their full extent. See Mr. Cope, “ On the Origin of Genera,’ ^ tlie ‘ Proc. of Acad, Nat. Sc. of Philadelphia,’ Ocl. 18GS.
21(5
SEXUAL SELECTION : BIRDS.
Part ‘
beauty (luring many years after they are fully mature » this is the case with the train of the peacock, and ^ 1 tlie crest and plumes of certain herons ; for instance. b1L' Ardea Ludovicana ;40 hut it is very doubtful whethef the continued development of such feathers is tI,e lesult of the selection ot successive beneficial variatiou^ or merely of continuous growth. Most fishes contm'1^ increasing in size, as long as they are in good heah1' and have plenty of food ; and a somewhat similar may prevail with the plumes of birds.
Class Y. When the adults of both sexes have a ^ tinet winter and summer plumage, whether or not the i differs from the female, the young resemble the adult s °J both sexes in their winter dress, or much more rarely tn their summer dress, or they resemble the females do**’ or the young may have an intermediate character ; °f again, they may differ greatly from the adults in h(,t[ their seasonal plumages.— The cases in this class »re singularly complex; nor is this surprising, as tKf depend on inheritance, limited in a greater or lesS degree in three different ways, namely by sex, and the season of the year. In some cases the mfl1' viduals of the same species pass through at least We distinct states of plumage. With the species, in >vb’C ! the male di iters from the female during the sum1111'’' season alone, or, which is rarer, during both seasons- the young generally resemble the females— as "itH the so-called goldfinch of North America, and apP9' rently with the splendid Maluri of Australia.42 ^
40 Jerdon ‘Birds of India,’ vol. iii. p. 507, on the peacock. A°d°' non, ibid. vol. 111. p. 139, on the Arden.
pi'1
the
41 For illustrative oases see vo). iv. of Maegillivrav’s ‘ Hist. Birds;’ on Tringa, &c„ p. 229, 271; on the Machetes, p. 172; Charadnm hatmh, p. 118 ; on the Charadrim pluvialis, p. 0i- lor the goldfinch of N. America, Fringilla Mil, Lu>»->
C,,AP. XVI.
SEASONAL CHANGES OF PLUMAGE.
217
tlie
species, the sexes of which are alike during both
summer and winter, tiie young may resemble adults, firstly, in their winter dress ; secondly, ^Lcly occurs much more rarely, in their summer tj °8s > thirdly, they may be intermediate between j. 'ese two states ; and, fourthly, they may differ greatly of * the adults at all seasons. We have an instance the first of these four cases in one of the egrets y tudia ( Buphus coromandus), in which the young and adults of both sexes are white during the winter, adults becoming golden-buff during the summer. ^ dU the Gaper (Anastomus oscitans) of India we f.Uv° a similar case, but the colours are reversed;
the young and the adults of both sexes are grey du • lat"k during the winter, the adults becoming white Ong the summer.43 As an instance of the second hi*6’ the young of the razor-bill (Alca iorda, Linn.), au early state of plumage, are coloured like the 'fits during the summer; and the young of the ^ ite-crowned sparrow of North America (Fringilla ^c°phrys), as soon as fledged, have elegant white ^ ‘Pes on their heads, which are lost by the young and 6 °hl during the winter.44 With respect to the third ( ^Se> namely, that of the young having an intermediate factor between the summer and winter adult plum- fefes> Yarrell45 insists that this occurs with many
‘ Ii u Jon> 1 Omith. Biography,’ vnl. i. p. 172. For the Maluri, Gould’s ^adliook of the Birds of Australia,' vol. i. p. 318.
. * “W indebted to Mr. Blyth for information iu regard to the An "1*’ Beo ftlso Jordon, ‘Birds of India,’ vnl. iii. p, 741). On the ^tomns, see Blyth, in ‘ Ibis,’ 1867, p. 173.
0„ 1 the Aloa, see MacgiJIiviay, ‘ Hist. Brit. Birds,’ vol. v. p. 347.
hete^)e Fringilla kueophrys, Audubon, ibid. vol. ii. p. S9. I shall have to refer to tlie young of certain herons and egrets being
History of British Birds,’ vol. i. 1839, p. 159.
218
SEXUAL SELECTION: BIRDS.
PaR1 1
waders. Lastly, in regard to tlie young di greatly from both sexes in their adult summer winter plumages, this occurs with some herons ‘ll1' egrets of North America and India, — the young being white.
I will mako only a few remarks on these eompli011^ cases. When the young resemble the female in ^ summer dress, or the adults of both sexes in their win^ dress, the cases differ from those given under Classes * and III. only in the characters originally acquired V the males during the breeding-season, having l,eti Imited in their transmission to the corresponding se®®^ When the adults have a distinct summer and wkdf plumage, and the young- differ from both, the case " more difficult to understand. We may admit as P1^ bable that the young have retained an ancient shlt' of plumage ; we can account through sexual sele0tl<\ tor the summer or nuptial plumage of the adults? ^ how are we to account for their distinct winter plmuag'0 ' If we could admit that this plumage serves in all as a protection, its acquirement would he a sii»W affair , but there seems no good reason for this ,l mission. It may be suggested that the widely differeJ* conditions ol life during the winter and summer b#v acted in a direct manner on the plumage; this have had some effect, but I have not much confid®BC in so great a difference, as we sometimes see, bet"'01' the two plumages having been thus caused. A 1001 probable explanation is, that an ancient style of plutB1^1 ^ partially modified through the transference of characters from the summer plumage, has been reta'B< by the adults during the winter. Finally, all the in our pieseut class apparently depend on c-hara0!0
•iouS
acquired by the adult males, having been var limited in their transmission accordino- to age, se®
;lf
ISO0'
c«. XVI.
THE YOUNG LIKE ADULTS OF SAME SEX. 219
foll,
sex ; but it would not be worth while to attempt to
A
<nv out flies1 complex relations.
" LAss YI. The young in their first plumage differ
Y°'n each oilier according to sex ; the young males Se>nbling more or less closely the adult males, and the ■pin9 females more or less closely the adult, females. — 16 cases in the present class, though occurring' in
Nous
It
ad
*>at
groups, are not numerous ; yet, if experience
Hot taught us to the contrary, it seems the most Hfal thin" that the young should at first always j : ’nble to a certain extent, and gradually become N iUl(l more like, the adults of the same sex. The I 11 b male blackcap ( Sylvia atricapilla) lias a black tud, that of the female being reddish-brown; and I . Informed by Mr. Blyth, that the young of both sexes p" be distinguished by this character even as nestlings. ^ ff'e family of thrushes an unusual number of similar )ils<;s have been noticed; the male blackbird ( Tardus ,^yu^a) can bo distinguished in the nest from the female, file main wing-feathers, which are not moulted so 011 as the body-feathers, retain a brownish tint until the .^-“°nd general moult.46 The two sexes of the moek- ^■8 liird (T urduS polyglottus, Linn.) differ very little N each other, yet the males can easily be distin- Y'shed at a very early age from the females by shew- 8 more pure white.47 The males of a forest-thrush p of a rock-thrush (viz. Orocetes erythrogastra and j. tfrocincla cyanea ) have much of their plumage of a , ' blue, whilst the females are brown ; and the nestling
J^rvl 7 ....
j.( ’ les of both species have their main wing and tail- afbers edged with blue, whilst those of the female are
Blyth, in Charlesworth’s ‘ Mag. of Nat. Hist.’ vol. i. 1837, p. 362 ; 4. r°tn information given to me by him.
■'fuJubon, ‘ Ornith. Biography,’ vol. i. p. 113.
220
SEXUAL SELECTION: BIRDS.
Part1
e%ed with brown.48 So that the very same featlier* which in the young blackbird assume their mature racter and become black after the others, in these t"'° species assume this character and become blue be^ the others. Ihe most probable view with reference t these cases is that the males, differently from ^ occurs in Class I., have transmitted their colours b their male offspring at an earlier age than that which they themselves first acquired them; for if ^ bad varied whilst quite young, they would probate have transmitted all their characters to their offs]-11''11' of both sexes.49
In Aithurus pohjtmus (one of the humming-b'1^.' the male is splendidly coloured black and green, two of the tail-feathers are immensely lengthened; * ' , female has an ordinary tail and inconspicuous colon113’ now the young males, instead of resembling the . female, in accordance with the common rule, bet? from the first to assume the colours proper to tbel sex, and their tail-feathers soon become elonga*el I owe this information to Mr. Gould, who has g>v<f me the following more striking and as yet unpuD lished case. Two humming-birds belonging to /. genus Eustephanus, both beautifully coloured, inbab\ the small island of Juan Fernandez, and have al'Vi’k been ranked as specifically distinct. But it has l«te ; been ascertained that the one, which is of a rich
PT W'isM, in ‘Ibis,’ vol. vi. 1864, p. 65. Jerdon, lJ}it *
of India/ vol. 1. p. 515.
“i lhf‘ollo"'mS additional casos may be mentioned: the 7°^ males ot Tana,jm ruhra can be distinguished from the young (Audubon, * Onuth. Brogmphy,’ vol. iv. p. 392), and so it is nestlings of a h ue nuthatch, Dendrophila frontalis of India {3ef ‘Brrds of India, vol. i. p. 389). Mr. Blyth al,o informs me th»* ‘ sexes of the stoneehat, Saxicola ruUcola, are distinguishable at » Vl" early age.
THE YOUNG LIKE ADULTS OF SAME SEX. 221
C«. Xv
XVi.
'bro'vn colour with a golclen-red head, is the male, ^ st the other, which is elegantly variegated with tl and white with a metallic-green head, is the ie- Now the young from the first resemble to a ),f a’n extent the adults of the corresponding sex, the glance gradually becoming more and more com-
L
Ihi COnsidcirinS this hist case, if as before we take the Ik "I:i?e °f the young as our guide, it would appear C both sexes have been independently rendered if ul ; and not that the one sex has partially trans- its beauty to the other. The male apparently tirj) at(luir('d his bright colours through sexual selec- 111 the same manner as, for instance, the peacock or
A
fdsant in our first class of cases: and the female in Hi banie manner as the female Rhynchsea or Turnix
the
^ second class of cases. But there is much diffi- 6jj. -v in understanding how this could have been at the same time with the two sexes of the the 6 ,sPecies- Mr. Salvin states, as we have seen in t]|6 ei^bth chapter, that with certain humming-birds ^jt(tllaies greatly exceed in number the females, whilst t °ther species inhabiting the same country the S Srea% exceed tlio males. If, then, we might 'till'116 tbat duriDo some former lengthened period the U6 as °f the Juan Fernandez species had greatly ex- l6t. ed the females in number, but that during another tl^oned period the females had greatly exceeded titles, we could understand how the males at one i, ’ aud the females at another time, might have been o0] ered beautiful by the selection of the brighter- ti)j0lll'ed individuals of either sex; both sexes transmit- their characters to their young at a rather earlier & than usual. Whether this is the true explanation i
999
SEXUAL SELECTION: BIRDS.
PAB1
will not pretend to say ; but the case is too remar to be passed over without notice.
We have now seen in numerous instances under
,l^le
#
six classes, that an intimate relation exists between plumage of the young and that of the adults, eithef ^ one sex or both sexes. These relations are fairly "h explained on the principle that one sex — this being j the great majority of cases the male— Hist aeq113'^, through variation and sexual selection bright col°1^ or other ornaments, and transmitted them in var,a ways, in accordance with the recognised laws of ]'n ' , ritance. \\ 1 ) y variations have occurred at differ; periods of life, even sometimes with the species of same group, we do not know; but with resp6^.^ the form of transmission, one important detertfiu‘, “ cause seems to have lu cn the age at which the tions first appeared.
Ire
ooiw
m
rom the principle of inheritance at correspo ages, and from any variations in colour which ocO'j in the males at an early age not being then selects1 the contrary being often eliminated as dangerous, " 3 similar variations occurring at or near the Per3'° reproduction have been preserved, it follows
n\iS
ti’1?
plumage of the young will often have been left difie 3, or but little modified. We thus get some if * into the colouring of the progenitors of our e*3* gl]j species. In a vast number of species iu five out o ^ six classes ol eases, the adults of one sex or hot 1 brightly coloured, at least during the breeding-8^! whilst the young are invariably less brightly ooh,u than the adults, or are quite dull-coloured; for stance is known, as far as I can discover, of the )3 gj of dull-coloured species displaying bright colon1*'
Cli
['AI>. XVI.
COLOUR AND PROTECTION.
223
the
young of briglitly-coloured species being more
f.j'1 ,an% coloured than their parents. In the fourth however, in which the young and the old resemble 1 other, there are many species (though by no means ^ J brightly-coloured, and as these form whole groups, Ij . Illfly infer that their early progenitors were likewise ^'dly-coloured. With this exception, if we look to birds of the world, it appears that their beauty "s beeil greatiy increased since that period, of which luye a partial record in their immature plumage.
ki-1 ^ le Colour of the Plumage in relation to Pro- 'll l°n — It will have been seen that I cannot follow ViWallace. in the belief that dull colours when con- to the females have been in most cases specially 1^ for the sake of protection. There can, however,
d'a
■^d'pORe, so as to escape the notice of their enemies ; or, - Sutne instances, so as to approach their prey unob- v,1V(i(l, in the same maimer as owls have had their 0 diage rendered soft, that their flight may not he . ei'beard. Mr. Wallace remarks50
do doubt, as formerly remarked, that, both sexes of uy birds have had their colours modified for this
i,. -“iu. Mr. Wallace remarks50 that “it is only i, *d the tropics, among forests which never lose their K . 10 ge, that we find whole groups of birds, whose ■-f colour is green.”
folk
VUMV rr rmci iu
f colour is green.” It will he admitted by every p, ’’ 'vbo has ever tried, how difficult it is to distinguish l'ots in a leaf-covered tree. Nevertheless, we must re- (,] 'dber that many parrots are ornamented with crimson, and orange tints, which can hardly be protective, ’b peckers are eminently arboreal, but, besides green (jh there are many black, and black-and-white
U^s all the species being apparently exposed to
50 ‘ Westminster Review,’ July, 1S67, p. 5.
224
SEXUAL SELECTION: BIRDS.
Part1
nearly tlie same dangers. It is therefore probab^ that strongly-pronounced colours have been acquit by tree-haunting birds through sexual selection, b° that green tints have had an advantage throws , natural selection over other colours for the sake 0 protection.
In regard to birds which live on the ground, ev'eT-' one admits that they are coloured so as to imitate t'1*' surrounding surface. How difficult it is to see a P8j tridge, snipe, woodcock, certain plovers, larks, night-jars when crouched on the ground. Animals J”' habiting deserts offer the most striking instances, for ^ bare surface affords no concealment, and all the quadrupeds, reptiles, and birds depend for safety ^ their colours. As Mr. Tristram has remarked,6 ' regard to the inhabitants of the Sahara, all are Py| tected by their “ isabelline or sand-colour.” Calli°p my recollection the desert-birds which I had seen 1 South America, as well as most of the ground-b)r ^ in Great Britain, it appeared to me that both se* in such cases are generally coloured nearly alike. •“ cor lingly I applied to Mr. Tristram, with respect to 1 birds ot the Sahara, and he has kindly given me . ^ following information. There arc twenty-six spet!' j belonging to fifteen genera, which manifestly have 1
their plumage coloured in a protective manner ; ‘‘l ^ this colouring is all the more striking, as with ^ ot these birds it is different from that of their geners. Both sexes of thirteen out of the tweidf^ species are coloured in the same manner ; but t 1 belong to genera in which this rule commonly P vails, so that they tell us nothing about the protcc ^ colours being the same in both sexes of desert- bird15'
‘ Ibis, 1859, vol. i. p, 429, et seq .
J
COLOUR AND PROTECTION.
225
C«
4P- XVI.
tyi". °^er thirteen species, three belong to genera in jj. lt^ the sexes usually differ from each other, yet they til'.6 sexes alike. In the remaining ten species, differs from the female; but the diffei •ence is J! IUe^ chiefly to the under surface of the plumage, i( h is concealed when the bird crouches on the 0olUlKl; the head and back being of the same sand- °ured hue in both sexes. >So that in these ten the upper surfaces of both sexes have been kr i 0n aa^ rendered alike, through natural selection, tli le sake ot protection; whilst the lower surfaces of '^ules alone have been diversified through sexual S( ^!' tlou. for the sake of ornament. Here, as bot h I' f'ft are equally well protected, we clearly see that the tj, l' 68 have not been prevented through natural selcc- Wfi'1 *10111 inheriting the colours of their male parents : sit, 1°°^ to the law of sexually limited trausinis- !l; as before explained.
hii/'/'ii parts of the world both sexes of many soft-
especially those which frequent reeds
or
il]U.a^ i'“
Co,^ are obscurely coloured, bio doubt if their °']Irs had been brilliant, they would have been t|( ! 1 n:|o re conspicuous to their enemies ; hut whether hi- 1 tints have been specially gained for the protection seems, as far as I can judge, rather still more doubtful whether such
(1,
« of
C11'"
It
IS
bi
nt.
tjnts can have been gained for the sake of orna- We must, however, bear in mind that male
though dull-coloured, often differ much from 'rQalea> as witl1 tlie C0|n'nou sparrow, and this
N nr”"65
tlq' ’ to tlle belief that such colours have been gained of I’!*11 sexual selection, from being attractive. Many ii, soft-hilled birds are songsters ; and a discussion °rmer chapter should not be forgotten, in which 's shewn that the best songsters are rarely orna-
u.
226
sexual selection: birds.
PakI
It
mented with bright tints. It would appear that fenW0 birds, as a general rule, have selected their mat® either for their sweet voices or gay colours, but n° for both charms combined. Some species which a1® manifestly coloured for the sake of protection, as the jack-snipe, woodcock, and night-jar, are ^'e', wise marked and shaded, according to our stand®1 of taste, with extreme elegance. In such cases "e may conclude that both natural and sexual select0® have acted conjointly for protection and ornameIlt' Whether any bird exists which does not possess special attraction, by which to charm the opposite & may be doubted. When both sexes are so obscur coloured, that it would be rash to assume the a geJlC'
•ely
of sexual selection, and when no direct evidence
c®®
be advanced shewing that such colours serve as a Fr° tection, it is best to own complete ignorance of tl10 cause, or, which comes to nearly the same thing; ^ attribute the result to the direct action of the c0l) ditions of life.
cOF
There are many birds both sexes of which are spicuously, though not brilliantly coloured, such the numerous black, white, or piebald species ; these colours, are probably the result of sexual
ieF
bl®0*
tion. With the common blackbird, capercailzie, - p cock, black Scoter-duck (Oidemia), and even with of of the Birds of Paradise ( Lophorina atra), the >°a ^ alone are black, whilst the females are brown or )|l0_f tied; and there can hardly be a doubt that black11® ^
in these cases has been a sexually selected char®0 e
co# rck
bh'
Therefore it is in some degree probable that the plete or partial blackness of both sexes in such ^ as crows, certain cockatoos, storks, and swans, and 111 marine birds, is likewise the result of sexual se g, tion, accompanied by equal transmission to both sc^
CONSPICUOUS COLOURS.
227
Co.
Ap- XVI.
r blackness can hardly serve in any case as a pro-
e°tion 'tTT‘ ’ ’
. 1
s and in others in which both sexes are black,
_ 1 1 _ ,
6 beak or skin about the head is brightly coloured,
I)*1' ^le contrast thus afforded adds greatly to their eauty ; we see this in the bright yellow beak of the blackbird, in the crimson skin over the eyes of jj . black-cock and capercailzie, in the variously and
th.
.^ghtly-coloured beak of the Scoter-drake (Oidcmia), 0,, red beak of the chough ( Corvus graculus, Linn.), bhe black swan, and black stork. This leads me to >ark that it is not at all incredible that toucans may ^ e the enormous size of their beaks to sexual selec- °n> for the sake of displaying the diversified and vivid 'pes of colour, with which these organs are oma- j, fJUted.62 The naked skin at the base of the beak and nd the eyes is likewise often brilliantly coloured; tlj, VIr- Gould, in speaking of one species,63 says that „ e colours of the beak “ are doubtless in the finest most brilliant state during the time of pairing.” ^ 6l'e is no greater improbability in toucans being l'umbered with immense beaks, though, rendered, its
as possible by their cancellated structure, for l! °bject falsely appearing to us unimportant, namely, e display of fine colours, than that the male Argus
*>2 -w
Ni’sfactDry explanation has fiver been offered of the immense bu,) "n<1r still less of the bright colours, of the toucan’s beak. Mr. St ti ^ •rile Naturalist on the Amazons,’ vol. ii. 1863, p. 311) slates baiifi y use tlieir h0ak for reaching fruit at the extreme tips of the “M v *B ’ and likewise, as stated by other authors, for extracting eggs 'V | hg birds from the nests of other birds. Bui, as Mr. Bates admits, “ tll| “can scarcely be considered a very perfectly-formed instru- di'11 tor the end to which it is applied." The great bulk of the beak, til,. ?'vn ky its breadth, depth, as well as length, is not intelligible on s» if'v> that it serves merely as an organ of prehension.
t&mphastos corinotus, Gould’s ‘ Monograph of Ramphastidso.’
Q 2
228
sexual selection: birds.
Par!1
pheasant and some other birds should be enciunbei'et with plumes so long as to impede their flight.
In the same manner, as the males alone of varied species are black, the females being dull-coloui'eC ’ so in a few cases the males alone are either wholly or partially white, as with the several Bell-bk'^ of South America (Chasmorhynchus), the Antaictl‘ goose ( Bernicla aniardica), the silver-pheasant, whilst the females are brown or obscurely '
Therefore, on the same principle as before, it is l’1.'0” bable that both sexes of many birds, such as wblte cockatoos, several egrets with their beautiful p>lun,eS’ certain ibises, gulls, terns, &c., have acquired the'j more or less completely white plumage through seSUi\ selection. The species which iidiabit snowy region'1 0 course come under a different head. The white ph1".1 age of some of the above-named birds appears both sexes only when they are mature. This ’ likewise the case with certain gannets, tropic-h'1'^ &c‘., and with the snow-goose {Ans&r hyperboreus )• ' the latter breeds on the “ barren grounds,” when ^ covered with snow, and as it migrates southward din'111'’ the winter, there is no reason to suppose that its s&°' white adult plumage serves as a protection. In t *' case ot the Anas! omits oscitans previously alluded ^ we have still better evidence that the white plu is a nuptial character, for it is developed only dm11'^
the summer; the young in their immature state,
the adults in their winter dress, being grey and bhlC ^ With many kinds of gulls (Larus), the bead and become pure white during the summer, being or mottled during the winter and in the young st“ On the other hand, with the smaller gulls, or sea-n^'' (Gavia), and with some terns (Sterna), exacilv the ’ verse occurs; for the heads of the young birds du1,1't’
CONSPICUOUS COLOURS.
229
c«.
ip. XVI.
. 6 first year, and of tlie adults during the winter, are pure white, or much paler-coloured than during 'e breeding-season. These latter cases offer another st<ince of the capricious manner in which sexual se- ec-ti°n appears often to have acted.61 J he cause of aquatic birds having acquired a white lrUage so much more frequently than terrestrial birds, h|°bably depends on their large size and strong powers flight, so that they can easily defend themselves or , s< aPe from birds of prey, to which moreover they are "l much exposed. Consequently sexual selection lias ,lot heve been interfered with or guided for the sake of h’otection. No doubt, with birds which roam over the "lH‘ri ocean, the males and females could find each I ler much more easily when made conspicuous either b being perfectly white, or intensely black; so that
Ul
<*du
it discovers and flies down to a carcase floating the sea or cast up on the beach, will be seen from Steat distance, and will guide other birds of the same t A of distinct species, to the prey; but as this would ® a disadvantage to the first finders, the individuals Oeh were the whitest or blackest would not thus have | oeured more food than the less strougly coloured • I^b'bduals. Hence conspicuous colours cannot have t en gradually acquired for this purpose through na- selection.55
(-se colours may possibly serve the same end as the notes of many land-birds. A white or black bird,
Vo/ 0,1 Larus, Gavia, and Slerna, see Maogillivray, ‘ Hist. Brit. Birds, ’ bio 4 'do. 584, 626. On the Anser hyperboreus, Audubon, ‘ Ornifh. pLty’’ vol> iv' P' 562- 0n the Anastomus, Mr. Blyth, in ‘Ibis,’ 55 ’,P'
t)lf 6 luay be noticed that with vultures, which roam far and wide ,tjjf uob the higher regions of the atmosphere, like marine birds over 0cean, three or four species are almost wholly or largely white, and
230
SEXUAL selection: binds.
ParIj
As sexual selection depends on so fluctuating element as taste, we can understand how it is that w#lJ' in the same group of birds, with habits of life neafl' the same, there should exist white or nearly whk®’ as well as black, or nearly black species, — for instant’ white and black cockatoos, storks, ibises, swans, teO'5’ and petrels. Piebald birds likewise sometimes occll| in the same groups, for instance, the black-neck®'' swan, certain terns, and the common magpie. I’k®' a strong contrast in colour is agreeable to birds, may conclude, by looking through any large collect^ of specimens or scries of coloured plates, for the se*0’ frequently differ from each other in the male hav>11' the pale parts of a purer white, and the various^ coloured dark parts of still darker tints than in t'1‘ female.
It would even appear that mere novelty, or chaB»fc for the sake of change, has sometimes acted lik0 *' charm on female birds, in the same manner as chang^ of fashion with us. The Duke of Argyll says,66 — -and am glad to have the unusual satisfaction of foil lor even a short distance in his footsteps — “I am “ ancl more convinced that variety, mere variety, u be admitted to be an object and an aim in Nat111®’
I wish the Duke had explained what he here mean8 Nature. Is it meant that the Creator of the uuiv0^ ordained diversified results for His own satisfaction, m 0 that ol man ? The former notion seems to me as wanting in due reverence as the latter in probabil1^ Capriciousness of taste in the birds themselves appea!g a more fitting explanation. For example; the ’
many other species are black. This fact supports the conjecture tliese conspicuous colours may aid the sexes in finding each other n111 the breeding-season. • 0gg.
50 ‘ The Journal of Travel,’ edited by A. Murray, vol. i. 1868, V- '
NOVELTY ADMIRED.
231
C«.
XVI.
°f some parrots can hardly be said to be more beautiful, at least according to our taste, than the females, but iey differ from them in such points, as the male
hav
fe:
mg a rose-coloured collar instead of, as in the
111 ale, “a bright emeraldine narrow green collar;” or la fde male having a black collar instead of “ a yellow ' emi-collar in front,” with a pale roseate instead of a Pl'im-blue head.57 As so many male birds have for dieir chief ornament elongated tail-feathers or elongated crests, the shortened tail, formerly described in the ^le of a humming-bird, and the shortened crest of male goosander almost seem like one of the many °Pposite changes of fashion which we admire in our °'vn dresses.
konre members of the heron family offer a still more °hrious case of novelty in colouring having appa- 1 f*ntly been appreciated for the sake of novelty. The loung of the Ardea asha are white, the adults being ' ark slate-coloured ; and not only the young, but the ac|ults of the allied Buplius coromandus in their winter Pmrnage are white, this colour changing into a rich ^den-buff during the breeding-season. It is incredible ^at the young of these two species, as well as of some °flier members of the same family,58 should have been sP(-'cially rendered pure white and thus made conspi- eUous
to their enemies; or that the adults of one of ^ese two species should have been specially rendered "hite during the winter in a country which is never
n See Jerdon on the genus Pakeomis, 1 Birds of India,’ vol. i. p. _8-260,
i,J8 tile young of Ardea rafeecem and A. ccerulea of the U. States are c k 'ViSe waite, the adults being coloured in accordance with their spe- names. Audubon Ornith. Biography,’ vol. iii. p. 410; vol. iv. of seems rather pleased at the thought that this remarkable change Plumage will greatly “ disconcert the systemutists.”
232
SEXUAL SELECTION: BIRDS.
PAB'r 1
covered with snow. On the other hand we have rea®0** to believe that whiteness has been gained by many bMs as a sexual ornament. We may therefore conclude th1^ an early progenitor of the Ardea asha and the acquired a white plumage for nuptial purposes, i1,u transmitted this colour to t heir young; so that d11 young and the old became white "like certain exist'11" egiets , the whiteness having afterwards been retai*lt>l by the young whilst exchanged by the adults for strongly pronounced tints. But if we could look su) further backwards in time to the still earlier progenitor of these two species, we should probably see the ad«lts dark-coloured. I infer that this would be the case, the analogy of many other birds, which are dark wki,st young, and when adult are white ; and more especial1’ from the case of the Ardea gularis, the colours of wlik*1 are the reverse of those of A. asha, for the young f6 dark-coloured and the adults white, the young having retained a former state of plumage. It appears there* fore that the progenitors in their adult condition of Ardea asha, the Biiphus, and of some allies, have n ncb?r' gone, during a long line of descent, the following ckangeS of colour ; firstly a dark shade, secondly pure wbk6’ and thirdly, owing to another change of fashion (# may so express myself), their present slatv, reddish, °r golden-buff tints. These successive changes are telligible only on the principle of novelty having heelJ admired by birds for the sake of novelty.
. Summary of the Four Chapters on Birds.— Mo st «lilIe birds are highly pugnacious during the breeding-sea®0*1’ and some possess weapons especially adapted for fig11*' ing with their rivals. But the most pugnacious and th* best-armed males rarely or never depend for succeSS solely on their power to drive away or kill their riv»ls>
SUMMARY.
233
or of producing instrumental music, and the males consequence differ from the females in their vocal
Vp. xvl
Jth have special means for charming the female. With
°!ne it is the power of song, or of emitting strange cries, in
^bans, or in the structure of certain feathers. From e curiously diversified means for producing various 1U(ls we gain a high idea of the importance of this Cana of courtship. Many birds endeavour to charm e females by love-dances or antics, performed on the ^"Und or in the air, and sometimes at prepared places.
Il' ornaments of many kinds, the most brilliant tints, ,',lnbs and wattles, beautiful plumes, elongated feathers, H'knots,
'tea
?cted
and so forth, are by far the commonest ills. In some cases mere novelty appears to have
as a charm. The ornaments of the males must
6 highly important to them, for they have been ac-
Fifed in not a few cases at the cost of increased danger
f111 enemies, and even at some loss of power in fight-
.§ "ith their rivals. The males of very many spe-
Cle® do not assume their ornamental dress until they
^'ive at maturity, or they assume it ouly during the
feeding-season, or the tints then become more vivid.
Main ornamental appendages become enlarged, turgid,
brightly-coloured during the very act of courtship.
'e males display their charms with elaborate care and to p 1 J
th.
, Mr, and many males and females congregate at an ^Pointed place. To suppose that the females do not fht'eciute the beauty of the males is to admit that
are Povvi
'be best effect ; and this is done in the presence of females. The courtship is sometimes a prolonged
splendid decorations, all their pomp and display, Useless ; and this is incredible. Birds have fine ers of discrimination, and in some few instances it y'1 be shewn that they have a taste for the beautiful
rbb,
6 females, moreover, are known occasionally to
234
SEXUAL SELECTION: BIBDS.
Part*
exhibit a marked preference or antipathy for certa1® individual males.
If it be admitted that the females prefer, or flI< unconsciously excited by the more beautiful males, d|£l the males would slowly but surely be rendered and more attractive through sexual selection. That 1 ' is this sex which has been chiefly modified vve may h1^ from the fact that in almost every genus in which th® sexes differ, the males differ much more from each otk'1 than do the females ; this is well shewn in certain clo^' allied representative species in which the females hardly be distinguished, whilst the males are quite tinct. Birds in a state of nature offer individual diffelj ences which would amply suffice for the work of seS>u‘ selection ; but we have seen that they occasionally f6' sent more strongly-marked variations which recti*' frequently that they would immediately be fixed- 1 they served to allure the female. The law’s of vari&tio5) will have determined the nature of the initial cbai'g£v' and largely influenced the final result. The g*"’1^ tions, which may be observed between the males ® allied species, indicate the nature of the steps whi^ have been passed through, and explain in the 111 ^ interesting manner certain characters, such as * \ indented ocelli of the tail-feathers of the peacock, a11 , the wonderfully-shaded ocelli of the wing-feather^ the Argus pheasant. It is evident that the briU1'®? colours, top-knots, fine plumes, Ac., of many ^ , birds cannot have been acquired as a protect*011’ indeed they sometimes lead to danger. That thjv are not due to the direct and definite action of *
conditions of life,
tb«
we may feel assured, because ^ females have been exposed to the same conditions, ^ yet often differ from the males to an extreme deg1^ Although it is probable that changed conditions act*11*
SUMMARY.
235
c«.
«>. XVI.
' llT'ing a lengthened period have produced some definite ^fi^ct on both sexes, the more important result will have ’a<-'n an increased tendency to fluctuating variability or
0 a,Igmented individual differences; and such differ- ^Ces will have afforded an excellent groundwork for
J,;‘ action of sexual selection.
J’he laws of inheritance, irrespectively of selection, aPpear to have determined whether the characters ac- j'lired by the males for the sake of ornament, for pro-
1 Ucitlg various sounds, and for fighting together, have e,-J1 transmitted to the males alone or to botii sexes,
e,ther permanently or periodically during certain sea- s°lis of the year. Why various characters should sonie- have been transmitted in one way and sometimes Mother is, in most cases, not known ; but the period Variability seems often to have been the determining r'ai|se. When the two sexes have inherited all charac- |f‘ls in common they necessarily resemble each other ; ^ as the successive variations may be differently trans- mitted, every possible gradation may he found, even '''thin the same genus, from the closest similarity to l° widest dissimilarity between the sexes. With many ' ',S(dy-ailied species, following nearly the same habits °J life, the males have come to differ from each other hlefly through the action of sexual selection; whilst . It! females have come to differ chiefly from partaking m a greater or lesser degree of the characters thus
8ft
vfiuired by the males. The effects, moreover, of the , finite action of the conditions of life, will not have
l^eu masked in the females, as in the case of the males, the accumulation through sexual selection of strongly- <1,Jnouuced colours and other ornaments. The iudi- j_1(luals of both sexes, however affected, will have been ^'Tt at each successive period nearly uniform by the ee intercrossing of many individuals.
236
SEXUAL SELECTION: BIRDS.
Par! ‘
With the species, in which the sexes differ in colotir’ it is possible that at first there existed a tendency ^ transmit the successive variations equally to both seS68’ and that the females were prevented from acquiring ^ bright colours of the males, on account of tlm danger which they would have been exposed during incubati^11 Lut it would be, as lar as I can see, an extremely cult process to convert, by means of natural selection, oJ)(, form of transmission into another. On the other ha')L there would not be the least difficulty in rendering “ female (lull-coloured, the male being still kept brig1'*' coloured, by the selection of successive variations, "In1 ( weie from the first limited in their transmission to same sex. Whether the females of many species b9' actually been thus modified, must at present rein91'1 doubtful. When, through the law of the equal mission of characters to both sexes, the females h»ve been rendered as conspicuously coloured as the m9^’ their instincts have often been modified, and they 1‘W been led to build domed or concealed nests.
In one small and curious class of cases the ebarac^ and habits of the two sexes have been completely t’9"5 posed, for the females are larger, stronger, more ferous and brightly-coloured than their males, have, also, become so quarrelsome that they often fir together like the males of the most pugnacious It, as seems probable, they habitually drive away rlf!l females, and by the display of their bright colours 1 other charms endeavour to attract the mates, we c'g understand how it is that they have gradually been *eJ\ tiered, by means ol sexual selection and sexually-li®1^ transmission, more beautiful than the males— the hltte being left unmodified or only slightly modified. .
Whenever the law of inheritance at correspond111® ages prevails, but not that of sexually-limited tra*
SUMMARY.
237
C«.
;4P. XVI.
lesion, then if the parents vary late in life — and we 0c°w that this constantly occurs with our poultry, and casionally with other birds — the young will be left ^affected, whilst the adults of both sexes will be .'i 'fled. If both these laws of inheritance prevail and j 1,‘r sex varies late in life, that sex alone will be 'hilled, the other sex and the young being left un- (‘lw;ted. When variations in brightness or in other “•pbuon. characters occur early in life, as no doubt .<jl1 happens, they will not be acted on through sexual f Action until the period of reproduction arrives ; eonse- lllt!ntly they will, if dangerous to the young, be elimi- cted through natural selection. Thus we can under- llcj how it is that variations arising late in life have °ften been preserved for the ornamentation of the ales- the females and the young being left almost un- ^ ected, and therefore like each other. With species ^riiig a distinct summer and winter plumage, the males ^ 'ybich either resemble or differ from the females ^ llQg both seasons or during the summer aloue, the s=?ees and kinds of resemblance between the young , ' the old are exceedingly complex; and this com- j. exjty apparently depends on characters, first acquired r|- ^he males, being transmitted in various ways and el'ces, as limited by age, sex, and season.
the young of so many species have been but little quilled in colour and in other ornaments, we are Jj^Ued to form some judgment with respect to the ^’ttnage of their early progenitors ; and we may infer at tUe beauty of our existing species, if wo look to the 0j.'° e class, has been largely increased since that period lv "hieh the immature plumage gives us an indirect cord. Many birds, especially those which live much the ground, have undoubtedly been obscurely co-
0|ii'ed
for the sake of protection. In some instances
238
sexual selection: birds.
PabT*
the upper exposed surface of the plumage has been thu® coloured in both sexes, whilst the lower surface in y'11 males alone has been variously ornamented throng'1 sexual selection. Finally, from the facts given in tl'eS® four chapters, we may conclude that weapons for battle organs for producing sound, ornaments of many bright and conspicuous colours, have generally be^ acquired by the males through variation and ses«‘l1 selection, and have been transmitted in various n'».yS according to the several laws of inheritance— the i’(;' males and the young being left comparatively but l^6 modified."
59 I am greatly indebted to the kindness of Mr. Selater for ha*1®* looked over these four chapters on birds, and tho two following on mammals. By this means I have been saved from making about the names of the species, and from giving any facts which af actually known to this distinguished naturalist to be erroneous. of course lie is not at all answerable for tho accuracy of the statenV11 5 quoted by me from various authorities.
SEXUAL SELECTION: MAMMALS.
239
ClUp. XVII,
CHAPTER XVII.
Secondary Sexual Characters of Mammals.
Tl
lt- 'a'v of battle — Special weapons, confined to the males — Cause absence of weapons in the female — Weapons common to both s°St's, yet primarily acquired by tlio male — Other uses of such 'voapons — Their high importance — Greater size of the male — ®eans of' defence — On the preference shewn by either sex in the Pairing of quadrupeds.
^ H’h mammals the male appears to win the female more through the law of battle than through the lsplay of his charms. The most timid animals, not ,^°Vided with any special weapons for fighting, engage 1 desperate conflicts during the season of love. Two hle hares have been seen to fight together until one ,&s killed ; male moles often fight, and sometimes with « !li results ; male squirrels “ engage in frequent eon- ests, and often wound each other severely;” as do j beavers, so that “ hardly a shin is without scars.”1 observed the same fact with the hides of the
hbs
red the same fact with the hides of the guana- in Patagonia ; and on one occasion several were so s°rbed in fighting that they fearlessly rushed close by e’ Livingstone speaks of the males of the many ani-
V. , — v v — “ JliCUlV CILIA-
^ais in Southern Africa as almost invariably shewing le sears received iu former contests.
^be law of battle prevails with aquatic as with ter-
1§, ®eo Waterton’s account of two bares fighting, ‘ Zoologist,’ vol.
{,• jg P- 21] . On moles, Bell, * Hist, of British Quadrupeds,* 1st edit, of \T ^ On squirrels, Audubon and Bachman, ‘ Viviparous Quadrupeds of 1 ; -America,’ 184G, p. 269. On beavers, Mr. A. H. Green, in ‘ Journal
240
SEXUAL selection: mammals.
Part '
,d
restrial mammals. It is notorious how desperately seals fight, hotli with their teeth and claws, during fbe breeding-season ; and their hides are likewise oft611 covered with scars, Male sperm-whales are very lous at this season; and in their battles “they oft#} “ lock their jaws together, and turn on their sides «»" twist about ; so that it is believed by some naturalist that the frequently deformed state of their lower jaws caused by these struggles.2
All male animals which are furnished with specif weapons for fighting, are well known to engage in fieA'e battles. The courage and the desperate conflicts of s tags have often been described ; their skeletons have bee11
found in various parts of the world, with the horns extricably locked together, shewing how miserably victor and vanquished had perished.3 No animal in ^ world is so dangerous as an elephant in must. L°n Tankerville has given me a graphic description of r',e battles between the wild bulls in Chillingham l>ar^’ the descendants degenerated in size hut not" iu courage of the gigantic Bos primigenius. In 1861 several co]l' tended lor mastery ; and it was observed that two 0 the younger bulls attacked in concert the old of the herd, overthrew and disabled him, so that he believed by the keepers to be lying mortally wounde in a neighbouring wood. But a few days afterwards 0>'e of the young bulls singly approached the wood ; ftI,t
‘ 0n file„.bflU11es of seals- see Cajit, C. Abbott in ‘Proc. Zool- 1868, p. LII ; also Mr. li. Brown, ibid. 186S, p. 486: also D- L10'
‘ Game 01 Sweden.’ 1S67, p. 412 ; also Pennant. On the sFr“
whale, see Mr. ,T. II. Thompson, in ‘ Proo. Zool. Soc.’ 1867, p- 2Jt:'.
3 See Scrape (‘Art of Deer-stalking,’ p. 17) on the locking 1 ■ horns with tlie Cervns elaphus. Richardson, in * Fauna Bor. A®yp cana,’ 1829, p. 252, says that the wapiti, moose, and rein-deer have W found thus locked together. Sir A. Smith found at the Cape of lit?pe the skeletons oi two gnus in the same condition.
C|>AP. XVII.
LAW OF BATTLE.
241
^!en the “ monarch of the chase,” who had been lashing •ttiself up for vengeance, came out and, in a short ^nie killed his antagonist. He then quietly joined the and long held undisputed sway. Admiral Sir • J. Sulivan informs me that when he resided in the jdkland Islands he imported a young English stallion, '’eh, with eight mares, frequented the hills near Port Uliam. On these hills there were two wild stallions, ®'Wh with a small troop of mares; “and it is certain <( ^lat these stallions would never have approached each „ °t!ler without fighting. Both had tried singly to fight l( , e English horse and drive away his mares, but had ,. jailed. One day they came in together and attacked ({ ll,n- This was seen by the capitan who had charge of , the horses, and who, on riding to the spot, found one 1( 01 the two stallions engaged with the English horse, "hilst the other was driving away the mares, and had ( already separated four from the rest. The capitan „ titled the matter by driving the whole party into the , 1 0l'i'al, for the wild stallions would not leave the hi ares.”
•^ale animals already provided with efficient cutting • tearing teeth for the ordinary purposes of life, as j. the carnivora, insectivora, and rodents, are seldom Wished with weapons especially adapted for lighting j^tu their rivals. The case is very different with the J|;des of many other animals. We see this in the horns 8tags and of certain kinds of antelopes in which tB. females are hornless. With many animals the j^nine teeth in the upper or lower jaw, or in both, are ah'1011 larger in the males than in the females; or are ^.8e,it in the latter, with the exception sometimes of a (1' ^eu rudiment. Certain antelopes, the musk-deer, 0j!J,r"T- horse, hoar, various apes, seals, and the walrus, er instances of these several cases. In the females
V°P II. K
242
SEXUAL SELECTION: MAMMALS.
PakT 1
of the walrus the tusks are sometimes quite absent In the male elephant of India and in the male dugo**r the upper incisors form offensive weapons. In the narwhal one alone of the upper teeth is developed iJ1^ the well-known, spirally-twisted, so called horn, which *' sometimes from nine to ten feet in length. It is belief that the males use these horns for finlitinn together; 1°' “ an unbroken one can rarely be got, and occasion"**- “ one may be found with the point of another jam 111 e “ into the broken place.”6 The tooth on the opp°s*(t side of the head in the male consists of a rudiment abo*1 ten inches in length, which is embedded in the jaw- ^ is not, however, very uncommon to find double-hor"e‘ male narwhals in which both teetli are well develop6*' In the females both teeth are rudimentary. The n1*1 !j cachalot has a larger head than that of the female, **D it no doubt aids these animals in their aquatic bat^e“ Lastly, the adult male omithorhynchus is provided a remarkable apparatus, namely a spur on the fore-h^’ closely resembling the poison-fang of a venomous sn»be’ its use is not known, but we may suspect that it se?'6 as a weapon of offence.7 It is represented by a 1110 ’ rudiment in the female.
When the
whicl
:b
males are provided with weapons ■ . ,
the females do not possess, there can hardly be a do** that they are used for fighting with other males, aP that they have been acquired through sexual select*011
ON
4 Mr. Lftmont (‘ Seasons with the Sea-Horses,’ 1361, J>- 1^-) ' that a good tusk ot the male walrus weighs I pounds, and *s *01 ^,-t- than that of the female, which w< ighs about 3 pounds. The r»aIeS jj,, described as fighting ferociously. On the occasional absence °* ,,. tusks in the female, see Mr. It. Brown, -Proc. Zool, Soc.’ IS**8’ P’ *'
5 Owen, ‘Anatomy of Vertebrates,’ vol. iii. p. 283.
8 Mr. R. Brown, in ‘ Proc. Zool. Soc.’ 1869, p. 553. 6gg.
’ Owen on the Cachalot and Omithorhynchus ib'd. vol. in- P‘
611.
LAW OF BATTLE.
243
C«AF. XVII.
It is
have
°Win
not probable, at least in most cases, that the females * actually been saved from acquiring such weapons, lS to tbeir being useless and superfluous, or in some I d) injurious. On the contrary, as they are often used I' tbe males of many animals for various purposes, Jfe especially as a defence against their enemies, it is uprising fact that they are so poorly developed or Phte absent in the females. No doubt with female deer l development during each recurrent season of great
, fl n /.b * 1 1 • . 1 .1 «i m . , 1
th
lynching horns, and with female elephants the deve- P*hent of immense tusks, would have been a great oi vital power, on the admission that they were th 130 USe ^ie thinales. Consequently variations in e size of these organs, leading to their suppression, 0,dd have come under the control of natural selection, 11 If limited in their transmission to the female off- ^1’Ung would not have interfered with their develop- (j^ut t^rouSl1 sexual selection in the males. But how ^ fnls view can we explain the presence of horns in the 'hales of certain antelopes, and of tusks in the females ^ Hrany animals, which are only of slightly less size ilu in the males ? The explanation in almost all cases st> I believe, be sought in the laws of transmission.
|, the reindeer is the single species in the whole jt of Deer in which the female is furnished with 01 Us> though somewhat smaller, thinner, and less
bn
tl‘,;iHched than in the male, it might naturally he -j.^ught that they must be of some special use to her. pi e,e is, however, some evidence opposed to this view.
female retains her horns from the time when they th! developed, namely in September, throughout "in' VlUter’ Until JIay’ wlieQ slle br“gs forth her young ; t J! st the male casts his horns much earlier towards the °f November. As both sexes have the same require- 4£1ts and follow tbe same habits of life, and as tbe male
li 2
2M
SEXUAL SELECTION : MAMMALS.
PaRt‘
sheds his horns during the winter, it is very improba^® that tiiey can be of any special service to the fernale ■' this season, which includes the larger proportion oi time during which she hears horns. Nor is it probab1 tliat she can have inherited horns from some anck'1 progenitor of the whole family of deer, for, from the k( . ot the males alone of so many species in all quartet 0 the globe possessing horns, we may conclude that t^' was the primordial character of the group. Hence J appears that horns must have been transferred from t!‘J_ male to the female at a period subsequent to the di'’e^ gence of the various species from a common stock! that this was not effected for the sake of giving her 1)1 • special advantage.8
We know that the horns are developed at a unusually early age in the reindeer ; but what the ca'lS^ of tins may have been is not known. The effect, k° ever, has apparently been the transference of the holIlj, to both sexes. It is intelligible on the hypothesis^ pangenesis, that a very slight change in the constit'd11^ ot the male, either in the tissues of the forehead ot the gemmules of the horns, might lead to their e!“ ;
r&o*
st
development ; and as the young of both sexes nearly the same constitution before the period of r
rep
in
,r0'
'the
■se-
duction, the horns, if developed at an early age male, would tend to be developed equally’ in both se^)6 In support of this view, w e should bear in mind that ^ horns are always transmitted through the female ‘l that sire lias a latent capacity for their development’ we see in old or disease 1 females.9 Moreover tbe "
.If
,tr-
8 On the structure and shedding of tile horns of the reindr^1’ berg, ‘ Amoenitates Acad.’ voL iv. 1 788, p. 1*19. See Iiiohardsom ‘ J ^ Bor. Americana,’ p. 211, in regard to the American variety or **]* also Major W. Boss King, ‘ The Sportsman in Canada/ 1866, P’, jgjb
9 Isidore Geoffrey St. -Hilaire, ‘ Essais de Zoolog. General c» p. 513. Other masculine characters, besides the horns, are son10
LAW OF BATTLE.
245
c«.
:4p- XVII.
of
s°me other species of deer either normally or ocea- 0°nally exhibit rudiments of horns ; thus the female of ~r,Julus moschatm has “ bristly tufts, ending in a knob, « *lls^ead of a horn ; ” and “ in most specimens of the ^niale Wapiti (Cervus Canadensis ) there is a sharp °uy protuberance in the place of the horn.” 10 From
‘h
th,
ese several considerations we may conclude that the ^session of fairly well-developed horns by the female ^iudeer, is due to the males having first acquired them j8 weapons for fighting with other males ; and secondarily 0 their development from some unknown cause at an 'usually early age in the males, and their consequent uusmission to both sexes.
j -turning to the sheath-horned ruminants: with ante- ' l’Ca a graduated series can be formed, beginning with e species, the females of which are completely desti- te of horns — passing to those which have horns so Jail as to be almost rudimentary, as in Antilocapra ^ erieana — to those which have fairly well-developed 0ras, but manifestly smaller and thinner than in the ,aie, and sometimes of a different shape,11 and ending those in which both sexes have horns of equal size.
4S
with the reindeer, so with antelopes there exists a
Ration between the period of the development of the °l'us and their transmission to one or both sexes; it
oh l .arly transferred to the female; thus Mr. Boner, in speaking of an A. chamois (‘Chamois Hunting in the Mountains of Bavaria,’
•ij '0’ 2nd edit. p. 863), says, “ not only was the head very male-look- ti n§, but along the hack there was a ridge of long hair, nsually to be “"nd only in bucks.”
the Cervulus, Dr. Gray, ‘Catalogue of the Mammalia in
•p tkh Museum,’ part iii. p. 320. On the Cervus Canadensis or Wapiti
j/^don. j. Jj. Caton, ‘ Ottawa Acad, of Nat. Sciences,’ May, 1S6S.
0|, Dor instance the horns of the female Ant. Euchore resemble those < distinct species, viz. the Ant. Dorcas var. Corine, see Desmarest, lammalogie,’ p. 455.
246 sexual selection: mammals. pakt11,
is therefore probable that their presence or absence >r' the females of some species, and their more or less Yel" loct condition in the females of other species, depe^’ not on their being 0f some special use, but simply 0,1 the form of inheritance which has prevailed. It ;'1'" cords with this view that even in the same restricted genus both sexes of some species, and the males alon® of other species, are thus provided. It is a remarkable fact that, although the females of Antilope bezoai'^ are normally destitute of horns, Mr. Blyth has seen less than three females thus furnished ; and there *** no reason to suppose that, they were old or disease^ The males of this species have long straight spiral horns, nearly parallel to each other, and directed bad' wards. Those of the female, when present, are vetf different in shape, for they are not spiraled, a|)( spreading widely bend round, so that their points *re directed forwards. It is a still more remarkable &ct that in the castrated male, as Mr. Blyth informs me, d® horns are of the same peculiar shape as in the fern3^’ but longer and thicker. In all cases the difference* between the horns of the males and females, and ol castrated and entire males, probably depend on vari°fll\ causes, on the more or less complete transference 0 male characters to the females, — on the former std® of the progenitors of the species,— and partly perhaps ^ the horns being differently nourished, in nearly the manner as the spurs of the domestic cock, when insert into the comb or other parts of the body, assume vai’i°uS abnormal forms from being differently nourished.
In all the w ild species of goats and sheep the h oi°s are larger in the male than in the female, and are s o&e[ times cprite absent in the latter.13 In several domestjC
12 Gray, 1 Catalogue Mamm. Brit. Mus.’ part iii. IS52, p. 160>
LAW OF BATTLE.
247
Ch.
ap. XVII.
b:
*eeds of the sheep and goat, the males alone are fur- u,8hed with horns; and it is a significant fact, that in °ne such breed of sheep on the Guinea coast, the horns are not developed, as Mr. Win wood Eeade informs me, 1)1 the castrated male ; so that they are affected in this respect like the horns of stags. In some breeds, as in that of N. Wales, in which both sexes are properly l01'ned, the ewes arc very liable to he hornless. In theso same sheep, as I have been informed by a trust- worthy witness who purposely inspected a flock during *Jhe lambing-season, the horns at birth are generally !n°re fully developed in the male than in the female.
^ ith the adult musk-ox (Ovibos moschatus ) the horns of | he male are larger than those of the female, and in the Mter the bases do not touch.13 In regard to ordinary little Mr. Blyth remarks : “ In most of the wild bovine aiUmals the horns are both longer and thicker in the ‘‘ bull than in the cow, and in the cow-banteng (Bos sondaicus ) the horns are remarkably small, and in- clined much backwards. In the domestic races of ‘‘ cattle, both of the humped and bumpless types, the ' horns are short and thick in the bull, longer and ( aiore slender in the cow and ox ; and in the Indian buffalo, they are shorter and thicker in the bull, longer and more slender in the cow. In tho wild gaour (B. gaums ) the horns are mostly both longer and ‘ thicker in the bull than in the cow.” 14 Hence with sheath-horned ruminants the horns of the male are either longer or stronger than those of the female.
'ith the Rhinoceros simus, as I may here add, the horns of the female aro generally longer but less power- hd than in the male ; and in some other species of
13 Richardson, ‘ Fauna Bor. Americana,’ p. 278.
14 ‘ Land and Water,’ 1867, p. 316.
248
SEXUAL SELECTION- : MAMMALS.
Part
rhinoceros they are said to be shorter in the female.15 From these various facts we may conclude that hor»s of all kinds, even when they are equally developed & both sexes, were primarily acquired by the males & order to conquer other males, and have been tra»s' f erred more or less completely to tiie female, in relation to the force of the equal form of inheritance.
4 he tusks o( the elephant, in the different species ,a* races, differ according to sex, in nearly the same man|ier as the horns of ruminants. In India and Malacca tl>0 males alone are provided with well-developed tusk* 4he elephant of Ceylon is considered by most 11 a” tuialists as a distinct race, but by some as a distiu*^ species, and here “ not one in a hundred is found “tusks, the few that possess them being exclusive!/ “ males.” 16 The African elephant is undoubtedly ^ tmet, and the female has large, well-developed tusk* though not so large as those of the male. These d#' feiences in the tusks ol the several races and species elephants— the great variability of the horns of deed as notably in the wild reindeer — the occasional pre' seuce of horns in the female Antilope lezoartica—^0 presence of two tusks in some few male narwhals-'*0*3 complete absence of tusks in some female walruses,"' are all Instances of the extreme variability of second a1'/
®e*ual. chai'a<;ters, and of their extreme liability t0 differ m closely-allied forms.
Although tusks and horns appear in all cases to hllV0 been primarily developed as sexual weapons they ol*e° serve for other purposes. The elephant uses his tusks
15 Sir Andrew Smith, ‘ Zoology of S. Africa,’ pi. xix. Owen, ‘A119' tomy of Vertebrates,’ vol. iii. p. 624.
18 Sir J. Emerson Tennent, ‘Ceylon,’ 1S59, vol. ii p. 274. Malacca, ‘Journal of Indian Archipelago,’ vol. iv. p. 357.
LAW OF BATTLE.
249
C«4P. 3
XVII.
Ill
the
d
attacking the tiger ; according to Bruce, he scores trunks of trees until they can be easily thrown l,VVu* and he likewise thus extracts the farinaceous
^°ves of palms ; in Africa he often uses one tusk, this eiug always the same, to probe the ground and thus
h
to ascertain whether it will bear his weight. The bull defends the herd with h is horns ; and ll! elk in Sweden has been known, according to Lloyd, 1° strike a wolf dead with a single blow of bis great ^'Us. Many similar facts could bo given. One of the Ulost curious secondary uses to which the horns ot' any Rhinal are occasionally put, is that observed by Captain |ttton 17 with the wild goat ( Capra, wgagrus) of the Himalayas, and as it is said with the ibex, namely, that ^ ieQ the male accidentally falls from a height he e*ds inwards bis head, and, by alighting on bis mas- 1Ve horns, breaks the shock. The female cannot thus Se her horns, which are smaller, but from her more hriet disposition she does not so much need this strange *Ul'l of shield.
j. huch male animal uses his weapons in his own peeu- jrir lashion. The common ram makes a charge and ritts with such force with the bases of his horns, that I ^Ve seen a powerful man knocked over as easily as a uld. Goats and certain species of sheep, for instance I e Ovis cycloceros of Afghanistan,18 rear on their hind and then not only butt, but “ make a cut down t(llud a jerk up, with the ribbed front of their scimitar- (< ^Uiped born, as with a sabre. When the 0. cycloceros (( ^Backed a large domestic ram, who was a noted ririser, lie conquered him by the sheer novelty of his
„ 1 Calcutta .Journal of Nat. Hist.’ vol. ii. 1843, p. 526.
in ‘Land and Water,’ March, 1867, p. 134, on the
®°ati
10 1 tty of Capt. Hutton and others. For the wild Pembrokeshire
:s see the ‘Field,’ 1863, p. 150.
250
sexual selection: mammals.
PARI
“ inode of fighting, always closing at once with hi-' “ adversary, and catching him across the face and nose “with a sharp drawing jerk of his head, and the11 “ bounding out of the way before the blow could h “ returned.” In Pembrokeshire a male goat, the niaster of a flock which during several generations had rUl1 wild, was known to have killed several other males single combat; this goat possessed enormous hornft measuring 39 inches in a straight line from tip to tip' The common bull, as every one knows, gores and tosse® his opponent ; but the Italian buffalo is saicl never t° use his horns, he gives a tremendous blow- with h)S convex forehead, and then tramples on his fallen ene»V with his knees — an instinct which the common bull doe® not possess.19 Hence a dog wdio pins a buffalo W the nose is immediately crushed. We must, liowe^er’ remember that the Italian buffalo has long been doi»eS" ticated, and it is by no means certain that the wn parent-form had similarly shaped horns. Mr. Barth’* informs me that when a female Cape buffalo (Bub^t coffer) was turned into an enclosure with a bull 0 the same species, she attacked him, and he in retur pushed her about with great violence. But it 'vllS manifest to Mr. Bartlett that had not the hull she''1' dignified forbearance, he could easily have killed bel' by a single lateral thrust with his immense horns. r^e giraffe uses Ids short hair-covered horns, which rather longer in the male than in the female, i11 f curious manner ; for with his long neck he swings bIB head to either side, almost upside down, with sllC, torce, that I have seen a hard plank deeply indent by a single blow.
19 M. E. M. Bailly, “ sur l’usage des Comes,” &c., ‘ Annal. des Nat.’ tom. ii. 1824, p. 3G9.
Sc-
LAW OF BATTLE.
251
<5U:
p- XVII.
j ^ ith antelopes it is sometimes difficult to imagine °'v they can possibly use their curiously-shaped horns ;
the spiing-boc (Ant. euehore ) has rather short up- 1 Jglit horns, with the sharp points beut inwards almost ilt a right angle, so as to face each other ; Mr. Bartlett
doe.
thi
not know how they are used, but suggests that 6y would inflict a fearful wound down each side of le face of an antagonist. The slightly-curved horns of le Oryx leucoryx (fig. Cl) are directed backwards, and 1 e °f such length that their points reach beyond the
Fig. 61. Oryx leucoryx, male (from the Knowsley Menagerie).
Middle of the back, over which they stand in an almost Parallel line. Thus they seem singularly ill-fitted for Siting; but Mr. Bartlett informs me that when two , these animals prepare for battle, they kneel down, "rih their heads between their front legs, and in this '^titude the horns stand nearly parallel and close to i. 6 ground, with the points directed forwards and a de upwards. The combatants then gradually ap- proach each other and endeavour to get the upturned Points under each other’s bodies; if one succeeds in
252
SEXUAL selection: mammals.
Part ‘
doing this, he suddenly springs up, throwing up hi3 head at the same time, and can thus wound or perhap® even transfix his antagonist. Both animals always knee* down so as to guard as far as possible against tin3 manoeuvre. It has heen recorded that one of these antelopes has used his horns with effect even against ® lion; yet from being forced to place his head between the fore-legs in order to bring the points of the hoi'119 forward, he would generally be under a great <*lS' advantage when attacked by any other animal. It lS’ therefore, not probable that the horns have been modified into their present great length and peculiar position, aS a protection against beasts of prey. We can, howeveb see that as soon as some ancient male progenitor of tha Oryx acquired moderately long horns, directed a lit**15 backwards, he would be compelled in his battles wit*1 rival males to bend his head somewhat inwards or do"-11' wards, as is now done by certain stags ; and it is n°* improbable that he might have acquired the habit 0 at first occasionally and afterwards of regularly knee*' ing down. In this case it is almost certain that the males which possessed the longest horns would h»v0 had a great advantage over others with shorter hoi'119’ and then the horns would gradually have been i'eU| dered longer and longer, through sexual selection, unt1 they acquired their present extraordinary length illl‘ position.
With stags of many kinds the branching of the h01'^ offers a curious case of difficulty ; for certainly a sing10 straight point would inflict a much more serious worn1 than several diverging points. In Sir Philip BgerW'1 3 museum there is a horn of the red-deer (Cervus e^‘ pirns) thirty inches in length, with “not fewer tb»IJ “ fifteen snags or branches and at Moritzburg the?3 is still preserved a pair of antlers of a red-deer, shot 111
CBAP. XVIII.
LAW OP BATTLE.
253
. ^99 by Frederick I., each of which bears the aston- jfl'ing number of thirty-three branches. Richardson rjSUres a pair of antlers of the wild reindeer with twenty- 11 1,10 points.20 From the manner in which the horns 'lre branched, and more especially from deer being known occasionally to fight together by kicking with be-
clu
uteir fore-feet,21 M. Bailly actually came to the cou-
pon that their horns were more injurious than useful j° them ! But this author overlooks the pitched battles jetween rival males. As I felt much perplexed about *he use or advantage of the branches, 1 applied to Mr. IcNeill of Oolinsay, who has long and carefully ob- ^ved the habits of red-deer, and he informs me that 19 has never seen some of the branches brought into action, but that the brow-antlers, from inclining down- wards, are a great protection to the forehead, and their b°ints are likewise used in attack. Sir Philip Egerton *ds° informs me in regard both to red-deer and fallow- ( 9er, that when they fight they suddenly dash together, and getting their horns fixed against each other’s bodies a desperate struggle ensues. When one is at last °l-ced to yield and turn round, the victor endeavours *9 plunge his brow-antlers into his defeated foe. It lUs appears that the upper branches are used chiefly 0lj exclusively for pushing and fencing. Nevertheless "dh some species the upper branches are used as "Capons of offence; when a man was attacked by a
0 Owen, on the Horns of Ked-deer, 1 British Fossil Mammals,’ 1S46, ' *78 ; 1 Forest Creatures,’ by Charles Boiler, 1S6I, p. 70. 02. Bich- r‘‘s°u on the Horns of the Reindeer, ‘ Fauna Bor. Americana,’ 1S29, >’• 2-iO.
Hon. J. D. Caton (‘Ottawa Acad, of Nat. Science,’ May, 1SGS, p.
9),
says that the American deer fight with their fore-feet, after “ the
I"estion of superiority has been once settled and acknowledged in the ‘erd.” 3ayjy> « gul. pusage des Cornes,” * Annal es des Sc. Nat.’ tom. l' p. 371.
254
SEXUAL selection: mammals.
Part
Wapiti deer ( Cervus Canadensis ) in Judge Caton’s park in Ottawa, and several men tried to rescue him, the stag “ never raised his head from the ground ; in fact he kep* ‘his face almost flat on the ground, with his nose near!? “ between his fore-feet, except when he rolled his hea^ “ one side to take a new observation preparatory 1°, “ a plunge.” In this position the terminal points the horns were directed against his adversaries. 1 “rolling his head he necessarily raised it somewhat “because his antlers were so long that he could «ot “ roll his head without raising them on one side, whiJ® “on the other side they touched the ground.” T,lf’ stag by this procedure gradually drove the party ot rescuers backwards, to a distance of 150 or 200 feet- 1 and the attacked man was killed.22
Although the horns of stags are efficient weapo»s’ there can, I think, be no doubt that a single poipt would have been much more dangerous than a branched antler; and Judge Caton, who has had large exper)' ence with deer, fully concurs in this conclusion. ^0> do the branching horns, though highly important as !l means of defence against rival stags, appear perfect!' well adapted for this purpose, as they are liable t° become interlocked. The suspicion has therefore cross? my mind that they may serve partly as ornament”' That the branched antlers of stags, as well as elegant lyrated horns of certain antelopes, with the'| graceful double curvature, (fig. (12), are ornament1 in our eyes, no one will dispute. If, then, the bort1* like the splendid accoutrements of the knights of °1(l’ add to the noble appearance of stags and antelop1'' they may have been partly modified” for this purpose
See a most interesting account in the Appendix to Hon- J* ^ Caton’s paper, as above quoted.
LAW OF BATTLE.
255
Ctup. xvn.
''hough mainly for actual service in battle ; but I have 110 evidence in favour of this belief.
tv
S- 62. Strepsiceros Kudu (from Andrew Smith’s ‘ Zoology of South Africa ').
. . 11 interesting case has lately been published, from Ar,ch it appears that the horns of a deer in one district 1 the United States are now being modified through x,lal and natural selection. A writer in an excellent
256
SEXUAL SELECTION: MAMMALS.
PAR1 1
American Journal 23 says, tliat he has hunted for last twenty-one years in the Adirondack's, where tke Cervus Virginianus abounds. About fourteen years he first heard of spike-horn lucks. These became fi'°nl year to year more common; about five years ago
shot one, and subsequently another, and now they
lie
frequently killed. “The spike-horn differs great 1/ “from the common antler of the C. Virginianus. ^ “consists of a single spike, more slender than the antler’ “ and scarcely half so long, projecting forward from tl10 “ brow, and terminating in a very sharp point. It g‘veS “ a considerable advantage to its possessor over tl10 “common buck. Besides enabling him to run m°'e “swiftly through the thick woods and underbid'11 “(every hunter knows that does and yearling bu^'3 “run much more rapidly than the large bucks wheI> “armed with their cumbrous antlers), the spike-h0'1’ “is a more eifective weapon than the common aid^1' “ With this advantage the spike-horn bucks are gai^j- “upon the common bucks, and may, in time, enth'e- “supersede them in the Adirondacks. Undoubted? “the first spike-horn buck was merely an accident “freak of nature. But his spike-horns gavre him 1,1 “ advantage, and enabled him to propagate his peC" “liarity. Ilis descendants, having a like advance0’ “have propagated the peculiarity in a cousta»y “increasing ratio, till they are slowly crowding tlll? “antlered deer from the region they inhabit,”
Male quadrupeds which are furnished with tm' use them in various ways, as in the case of b°rI?Sj The boar strikes laterally and upwards; the mnS' deer with serious effect downwards.24 The wabub’
23 ‘ The American Naturalist,’ Dec. 1869, p. 552.
24 Pallas, 1 Spicilegia Zoologica,’ fasc. xiii, 1779, p.
LAW OF BATTLE.
257
°"W XVII.
°ugli having so short a neck and so unwieldy a body, (< Can strike either upwards, or downwards, or side- ^ 'Vavs, with equal dexterity.” 25 The Indian elephant ghts, as I was informed by the late Dr. Falconer, in a of ,ent manner according to the position and curvature ^is tusks. When they are directed forwards and P wards lie is able to fling a tiger to a great distance — 18 said to even thirty feet ; when they are short and Iried downwards lie endeavours suddenly to pin the d'er to the ground, and in consequence is danger- JlliS to the rider, who is liable to be jerked off the 10odah.26
^ Very few male quadrupeds possess weapons of two istiuet kinds specially adapted for fighting with rival |ales. The male muutjae-deer ( Gervulw ), however, ers an exception, as he is provided with horns and jetted canine teeth. But one form of weapon, has j, 611 been replaced in the course of ages by another ',|.rth as we may infer from what follows. With rn- . '“ants the development of horns generally stands an inverse relation with that of even moderately i ^-developed canine teeth. Thus camels, guanacoes, “GVrotains and musk-deer, are hornless, and they [(ave efficient canines; these teeth being “always of ^“'nailer size in the females than in the males.” The ti^mclidae have in their upper jaws, in addition to jj6'1' true canines, a pair of canine-shaped incisors.27 ^ d e deer and antelopes, on the other hand, possess and they rarely have canine teeth; and these 611 present are always of small size, so that it is
j8 Liuaout, 1 Seasons with the Sen-Horses,’ 18G1, p. HI. her • See als0 Corse (‘ Pliilosoph. Transact.’ 1799, p. 212) on the mnn- ot] 1,1 whieli the short-tusked Mooknah variety of the elephant attacks
elephants.
t*Wen, ‘Anatomy of Vertebrates,’ vol. iii. p. 349.
V°L. II. " S
258
SEXUAL SELECTION: MAMMALS.
Part
II.
doubtful whether they are of any service in theb battles. With Antilope montana they exist only rudiments in the young male, disappearing as be grows old ; and they are absent in the female il* all ages ; but the females of certain other antelope3 and deer have been known occasionally to exhibit rudiments of these teeth.23 Stallions have small cani»e teeth, which are either quite absent or rudimentari in the mare ; but they do not appear to be used 111 fighting, for stallions bite with their incisors, and &° not open their mouths widely like camels and guairi' coes. Whenever the adult male possesses canines n°" in an inefficient state, whilst the female has either »oI>0 or mere rudiments, we may conclude that the eaw male progenitor of the species was provided with e^' cient canines, which had been partially transferred the females. The reduction of these teeth in the ma^S seems to have followed from some change in tl|Cl1 manner of fighting, often caused (but not in the c^e of the horse) by the development of new weapons.
Tusks and horns are manifestly of high importance their possessors, for their development consumes ®uC organised matter. A single tusk of the Asiatic phant, — one of the extinct woolly species, — and of African elephant, have been known to weigh respectW' • lot), lliO, and 180 pounds; and even greater weigh have been assigned by some authors.29 With deer, 11
it®
!S See Itiippell (in Tree. Zoolog. Soc.’ Jan. 12, 183G, p. 3) on ^ canines in deer ancl antelopes, with a note by Mr. Martin on a ’ American deer. See also Falconer (‘Pa keen t. Mtmoirs and ^ vol. i. 1868, p. 576) on canines in an adult female dccr. In old ji. of the musk-deer the canines (Pallas, ‘Spic. Zoolog.’ fasc. xi.i- 18) sometimes grow to the length of three inches, whilst in old &&
a rudiment projects scarcely half an inch above the gums.
20 Emerson Tennent, ‘Ceylon,’ 1S59, vol. ii. p. 275; Owen, Fossil Mammals/ 1816, p. 245,
I3rit*Jl
°1UP. XVII.
LAW OF BATTLE.
259
'vhich the horns are periodically renewed, the drain 011 the constitution must be greater; the horns, for |llstance, of the moose weigh from fifty to sixty pounds, a,i(l those of the extinct Irish elk from sixty to seventy P°Unds, — the skull of the latter weighing on an average ?.nh five and a quarter pounds. With sheep, although horns are not periodically renewed, yet their de- velopment, in the opinion of many agriculturists, en- ails a sensible loss to the breeder. Stags, more- IVer. in escaping from beasts of prey are loaded with 11 additional weight for the race, and are greatly Warded in passing through a woody country. The v °0Se> for instance, with horns extending five and a Uilf feet
from tip to tip, although so skilful in their that he will not touch or break a dead twig vien walking quietly, cannot act so dexterously whilst Wishing away from a pack of wolves. “During his (< Jn'ogress he holds his nose up, so as to lay the (( l0|'us horizontally back ; and in this attitude cannot ?See the ground distinctly.” 30 The tips of the horns ,l. die great Irish oik were actually eight feet apart! uilst the horns are covered with velvet, which lasts *th the red-deer for about twelve weeks, they are ^tremely sensitive to a blow; so that in Germany 1 1® stags at this time change their habits to a cer- tUu extent, and avoid dense forests, frequenting young j'^ds and low' thickets.31 These facts remind us, that U!de birds have acquired ornamental plumes at the ^8t of retarded flight, and other ornaments at the cost sonie loss of power in their battles with rival males.
p ^t-'hardson, ‘Fauna Bor. Americana,’ on the moose, Alcea palmata, t8Cq 237 ’ al*° 011 tlie exPanso of the horns 1 Land and Water,’ (dr 5 P* 143 See also Owen, ‘ British Fossil Mammals, ’ on the Irish ,{P- 447, 455.
‘ Forest Creatures,’ by C. Boner, 1SG1, p. GO.
260 SEXUAL SELECTION: MAMMALS. PakT II'
With quadrupeds, when, as is often the case, the sexes differ in size, the males are, I believe, alwa)rS larger and stronger. This holds good in a marked manner, as I am informed by Mr. Gould, with the mai" supials of Australia, the males of which appear continue growing until an unusually late age. B1'* the most extraordinary case is that of one of fb® seals (Callorliinus ursinus), a full-grown female weigh' ing less than one-sixth of a full-grown male.32 'U1® greater strength of the male is invariably displayed’ as Hunter long ago remarked,33 in those parts of tbe body which are brought into action in fighting with rival males, — for instance, in the massive neck of tb0 bull. Male quadrupeds are also more courageous tlJI< pugnacious than the females. There can be little doubt that these characters have been gained, parti)' through sexual selection, owing to a long series of xl°' tories by the stronger and more courageous males o?e the weaker, and partly through the inherited effects 0 use. It is probable that the successive variations strength, size, and courage, whether due to so-call®1 spontaneous variability or to the effects of use, bv tb® accumulation of which male quadrupeds have acqud'f these characteristic qualities, occurred rather late life, and were consequently to a large extent limit0 in their transmission to the same sex.
Under this point of view I was anxious to obtc’1’ information in regard to the Scotch deer-hound, tb® sexes ot which differ more in size than those of aD' other breed (though blood-hounds differ consul01 ably), or than in any wild canine species known to IlU
32 See the very interesting paper by Mr. J. A. Allen in ‘ Bulb ^ Comp. Zoolog. of Cambridge; United States,' vol. ii. No. 1, p. 82. 1 weights were ascertained by a careful observer, Capt. Bryant.
33 1 Animal Economy, p. 45.
ClUp. XVII. GBEATEB SIZE OP THE MALE. 261
Accordingly, I applied to Mr. Cupples, a well-known breeder of these dogs, wlio has weighed and measured many of his own dogs, and who, with great kindness, has Collected for me the following facts from various sources. Superior male dogs, measured at the shoulder, range from twenty-eight inches, which is low, to thirty-three, 0r even thirty-four inches in height; and in weight from eighty pounds, which is low, to 120, or even more Pounds. The females range in height from twenty- ^tai'ee to twenty-seven, or even to twenty-eight inches ; aml in weight from fifty to seventy, or even eighty Pounds.31 Mr. Cupples concludes that from ninety -five to one hundred pounds for the male, and seventy for fre female, would be a safe average ; but there is reason fr believe that formerly both sexes attained a greater "’eight. Mr. Cupples has weighed puppies when a fortnight old ; in one litter the average weight of four males exceeded that of two females by six and a half Alices ; in another litter the average weight of four males exceeded that of one female by less than one °Unce ; the same males, when three weeks old, exceeded f^e female by seven and a half ounces, and at the age °f six weeks by nearly fourteen ounces. Mr. Wright m Yeldersley House, in a letter to Mr. Cupples, says : I have taken notes on the sizes and weights of puppies °f many litters, and as far as my experience goes, dog-pUppieS as a rule differ very little from bitches till they arrive at about five or six months old ; and
<{ j-i J , m 7
lhen the dogs begin to increase, gaining upon the
4 See also Richardson's ‘ Manual on the Dog,’ p. 59. Much valu- k information on the Scottish deer-hound is given by Mr. McNeill, J first called attention to the inequality in size between the sexes, in pope’s ‘ Art of Deer Stalking.’ I hope that Mr. (Jupples will keep to j^s intention of publishing a full account and history of this famous
262
SEXUAL selection: mammals.
Part 1
“ bitches both in weight and size. At birth, and f°r “ several weeks afterwards, a bitch-puppy will occS' “ sionallv be larger than any of the dogs, but they a*® “invariably beaten by them later.” Mr. McNeill? Oolinsay, concludes that “the males do not attain “ their lull growth till over two years old, though “the females attain it sooner.” According to Cupples’ experience, male dogs go on growing irl stature till they are from twelve to eighteen months old, and in weight till from eighteen to twenty-^1' months old ; whilst the females cease increasing ^ stature at the age of from nine to fourteen or fifte®® months, and in weight at the age of from twelve t0 fifteen months. From these various statements if clear that the full difference in size between th® male and female Scotch deer-hound is not acqnir®^ until rather late in life. The males are almost exd11 sively used for coursing, for, as Mr. McNeill inforn,s me, the females have not sufficient strength and weig1^ to pull down a full-grown deer. From the names «se<1 in old legends, it appears, as I hear from Mr. CuppleS’ that at a very ancient period the males were the m°st celebrated, the females being mentioned only as mothers of famous dogs. Hence during many genera tions, it is the male which has been chiefly testet for strength, size, speed, and courage, and the be® will have been bred from. As, however, the male® do not attain their full dimensions until a ratheI late period in life, they will have tended, in a<!' cordance with the law often indicated, to transit their characters to their male offspring alone; a01' thus the great inequality in size between the se$eS of the Scotch deer-hound may probably be account for.
The males of some few quadrupeds possess organ*
or
Ca.
'ap. XVII.
MEANS OP DEFENCE.
203
I^ts developed solely as a means of defence against ae attacks of other males. Some kinds of deer use, ap"’e have seen, the upper branches of their horns Chiefly or exclusively for defending themselves ; and , le Oryx antelope, as I am informed by Mr. Bartlett, .ebces most skilfully with his long, gently curved horns ; llt these are likewise used as organs of offence, lilii- ll°ceroses, as the same observer remarks, in fighting ^arry each other’s sidelong blows with their horns, ''tich loudly clatter together, as do the tusks of boars, ^though wild boars fight desperately together, they sOdotn, according to Brehm, receive fatal blows, as bese fall on each other’s tusks, or on the layer of pistly skin covering the shoulder, which the German 1,1 uters call tho shield ; and here we have a part speci- fy modified for defence. With boars in the prime °* life (see fig. 63) the tusks in the lower jaw ar® used for fighting ut they become in age, as Brehm . ates, so much curved hoards and upwards,
°ver the snout, that th,
ey can no longer be pus used. They
Head of common wild boar, in prime of life (from Brehm).
I ~ wouu, XUOJ IflUVj
l0Wever, still continue to serve, and even in F:g a still more efl’ective plnner, as a means of defence. In compensation for .b® loss of the lower tusks as weapons of offence, those 1,1 die upper jaw, which always project a little later- increase so much in length during old age, and cUrve so much upwards, that they can be used as a bieans of attack. Nevertheless an old boar is not so
264
sexual selection: mammals.
Part
II.
dangerous to man as one at the age of six or seven years.35
4n the full-grown male Babirusa pig of Celebes (fig. 64), the lower tusks are formidable weapons, b^e those of the European boar in the prime of life, whdst the upper tusks are so long and have their points s<5 much curled inwards, sometimes even touching the
Fig. U. Skull ul the Uttbirusa Pig (f><™ Wallace's ‘ Malay Archipelago )
forehead, that they are utterly useless as weapons attack. They more nearly resemble horns than teeth* and are so manifestly useless as teeth that the ani®al was formerly supposed to rest his head by hooking the10 on to a branch. Their convex surfaces would, however*
35 Brehm, ‘ Thierleben,’ B. ii. s. 720-732.
CH4P. XVII.
MEANS OF DEFENCE.
265
^ the lieacl were held a little laterally, serve as an excellent guard ; and hence, perhaps it is that in °fd animals they “ are generally broken off, as if by ‘ %hting.”36 Here, then, we have the curious case of t!le upper tusks of the Babimsa regularly assuming ■taring the prime of life, a structure which apparently l'°nders them fitted only for defence ; whilst in the Euro- Pean boar the lower aud opposite tusks assume in a less 'tagree and only during old age nearly the same form, a,ul then serve in like manner solely for defence.
lS- 65. Head of ^Ethiopian Wart-hog, from 1 Proc. Zool. Soc.* 1869. (I now find that this drawing represents the head of a female, but it serves to shew, on a reduced Scale, the characters of the male.)
In the wart-hog ( Phacoclioerus ssthiopicus, fig. 65) ttae tusks in the upper jaw of the male curve upwards during the prime of life, and from being pointed, S(il've as formidable weapons. The tusks in the lower .law are sharper than those in the upper, but from their shortness it seems hardly possible that they can be used as weapons of attack. They must, however, greatly
3c See Mr. Wallace’s interesting account of this animal, 1 The Malay ^’chipelago,’ 1869, vol. i. p. 435.
266
SEXUAL selection: mammals.
Part j
strengthen those in the upper jaw, from being ground so as to fit closely against their bases. Neither the upper nor the lower tusks appear to have been sped' ally modified to act as guards, though, no doubt, the/ are thus used to a certain extent. But the wart-hog lS not destitute of other special means of protection, there exists, on each side of the face, beneath the eye"’ a rather stiff, yet flexible, cartilaginous, oblong Pa^ (fig. 65), which projects two or three inches outwards J and it appeared to Mr. Bartlett and myself, when vie"" ing the living animal, that these pads, when struck fm111 beneath by the tusks of an opponent, would be turned upwards, and would thus protect in an admirable ma*1' ner the somewhat prominent eyes. These boars, as *■ may add on the authority of Mr. Bartlett, when fighting together, stand directly face to face.
Lastly, the African river-hog ( Potamochoerus latus) has a hard cartilaginous knob on each side the face beneath the eyes, which answers to the fiexide pad of the wart-hog ; it has also two bony prominency on the upper jaw above the nostrils. A boar of ti’jS species in the Zoological Gardens recently broke iIlt0 the cage of the wart-hog. They fought all night-l°nc’ and were found in the morning much exhausted, not seriously wounded. It is a significant fact, shewing Iho purpose of the above-described projection® and excrescences, that these were covered with blo° ’ and were scored and abraded in an extraordina1/ manner.
Ihe mane of the lion forms a good defence agalllS^ the one danger to which he is liable, namely the at- tacks of rival lions : for the males, as Sir. A. Smdjl informs me, engage in terrible battles, and a y °nnS lion dares not approach an old one. In 1857 a tiger at Bromwich broke into the cage of a lion, and :l
MEANS OF DEFENCE.
267
cHap. xvii.
jarful scene ensued ; “ the lion’s mane saved his neck (( ar'd head from being much injured, but the tiger at W succeeded in ripping up ids belly, and in a few minutes he was dead.”37 The broad ruff round the .oat and chin of the Canadian lynx (Felis Canadensis) much longer in the male than in the female ; but " bether it serves as a defence I do not know. Male 8ea-ls are well known to fight desperately together, and bbe males of certain kinds {Otaria jubata) 33 have great Jjmnes, whilst the females have small ones or none. Ibe male baboon of the Capo of Good Hope ( Cynoce - Phalus forcarius) has a much longer mane anti larger Cauine teeth than the female ; and the mane probably ?erVes as a protection, for on asking the keepers 111 the Zoological Gardens, without giving them any C!bie to my object, whether any of the monkeys espe- faally attacked each other by the nape of the neck, I "as answered that this was not the case, excepting with |be above baboon. In the Ilamadryas baboon, Eliren- e,'g compares the mane of the adult male to that a young lion, whilst in the young of both sexes and la the female the mane is almost absent.
It appeared to me probable that the immense woolly r,lurie of the male American bison, which reaches ‘brnost to the ground, and is much more developed 1(1 the males than in the females, served as a pro- motion to them in their terrible battles; but an ex- perienced hunter told Judge Caton that he had never observed anything which favoured this belief. The
‘Tlie Times,’ Nov. 10th, 1807. In regard to the Canada lynx, 60 Audubon and Bachman, ‘ Quadrupeds of N. America,’ ISIS, p. 139. . Dr. Marie, on Otaria, ‘Proc. Zoolog. Soc.’ 1809, p. 109. Mr. J. A. Jkn, iu paper above quoted (p. 75), doubts whether the hair, ^vnieh is longer on the neck in the male than in the female, deserves to 6 called a mane.
268
sexual selection: mammals.
part*
stallion has a thicker and fuller mane than the mar®’ and I have made particular inquiries of two g'1®® trainers and breeders who have had charge of m*111' entire horses, and am assured that they “invariable “ endeavour to seize one another by the neck.” f does not, however, follow from the foregoing st®t® ments, that alien the hair on the neck serves a® defence, that it was originally developed for this p1'1 pose, though this is probable in some cases, as in lb11 of the lion. I am informed by Mr. McNeill that th® long hairs on the throat of the stag ( Cervus ele^:tS> serve as a great protection to him when hunted, 1°* the dogs generally endeavour to seize him by th® throat; but it is not probable that these hairs W®r0 specially developed for this purpose; otherwise the young and the females would, as we may feel assured have been equally protected.
On Preference or Choice in Pairing, as shewn byei^eT sex oj Quadrupeds, — Before describing, in the next chap ter, the differences between the sexes in voice, odo11^ emitted, and ornamentation, it will be convenient h'-u to consider whether the sexes exert any choice in th®11 unions. Does the female prefer any particular either before or after the males- may have fought t0 gethei for supremacy; or does the male, when notap0^* gamist, select any particular female ? The general ho pression amongst breeders seems to be that the B1® 6 accepts any female; and this, owing to his eager*1®88’ is, in most cases, probably the truth. Whether th® female as a general rule indifferently accepts any m® 6 is much more doubtful. In the fourteenth chapt®1’’ on Birds, a considerable body of direct and indir®®1 evidence was advanced, shewing that the female sele®18 her partner ; and it would be a strange anomaly 1
PREFERENCES IN PAIRING.
2G9
Cir.
Ap- XVII.
quadrupeds, which stand higher in the scale of 0,'ganisation and have higlier mental powers, did not kciierally, or at least often, exert some choice. The C'nale could in most cases escape, if wooed by a male 'at did not please or excite her; and when pursued, so incessantly occurs, by several males, she would ^ten have the opportunity, whilst they were fighting l°gether, of escaping with, or at least of temporarily hairing with, some one male. This latter contingency as often been observed in Scotland with female red- eei’> as I have been informed by Sir Philip Egerton.39 It is scarcely possible that much should be known ,0ut female quadrupeds exerting in a state of nature aa.V choice in their marriage unions. The following
V O o
ery curious details on the courtship of one of the 6iil‘ed seals, Gallorhinus ursinus, are given 40 on the 3l'thority of Capt. Bryant, who had ample opportunities l(°1' observation. He says, “Many of the females on l( tueir arrival at the island where they breed appear losirous of returning to some particular male, and , h’^quently climb the outlying rocks to overlook the I'ookcrics, calling out and listening as if for a familiar
Voice.
same
Then changing to another place they do the As soon as a female reaches the
again . .
i( sWe, the nearest male goes down to meet her, making "‘can while a noise like the clucking of a hen to her chickens. He bows to her and coaxes her until he gets between her and the water so that she cannot escape him. Then his manner changes, and with a
Mr. Boner in his excellent description of the habits of the red- «e®r Germany (‘Forest Creatures,’ 1801, p. 81) says, “ while the a staS is defending his rights against one intruder, another invades the n sanctuary of his harem, and carries off trophy after trophy.” Exactly ^sanie thing occurs with seals, see Mr. J. A. Allen, ibid. p. 100.
Mr. J. A. Allen in ‘ Bull. Mus. Comp. Zoolog. of Cambridge, United tatcs,’ vol. ii. No. 1, p. 99.
270
SEXUAL SELECTION : MAMMALS.
Part
II.
“ harsh growl lie drives her to a place in his hare#' “ 1 his continues until the lower row of harems # “ nearly full. Tlien the males higher up select tl# “ time when their more fortunate neighbours are <# “ their guard to steal their wives. This they do h? “ taking them in their mouths and lifting them ov# “ the heads of the other females, and carefully placing “ them in their own harem, carrying them as cats “ their kittens. Those still higher up pursue the sa#° “ method until the whole space is occupied. Frequently “ a struggle ensues between two males for the posses#01* “ of the same female, and both seizing her at once pul “ her in two or terribly lacerate her with their teeth' “ When the space is all filled, the old male walks aroi#tl “complacently reviewing his family, scolding tl#se
who crowd or disturb the others, and fiercely drivh’S’
“ off all intruders. This surveillance always keeps hi#
“ actively occupied.”
As so little is known about the courtship of animals i*1 a state of nature, I have endeavoured to discover how #r our domesticated quadrupeds evince any choice in th#r unions. Dogs offer the best opportunity for observation as they are carefully attended to and well understood Many breeders have expressed a strong opinion on tlj,!5 head. Thus Mr. Mayhew remarks, “ The females aJ'° “able to bestow their affections; and tender recoil#
“ ti°us are as potent over them as they are known “ be in other cases, where higher animals are “ cerned. Bitches are not always prudent in tin#
“ loves, but are apt to fling themselves away on ®
“ of low degree. If reared with a companion of vulg#'
“ appearance, there often springs up between the pa#
“ devotion which no time can afterwards subdue. 'L'l,e “ passion, for such it really is, becomes of a more than “romantic endurance.” Mr. Mayhew, who attend#1
PREFERENCES IN PAIRING.
271
Cit.
AP- XVII.
chiefly to the smaller breeds, is convinced that the emales are strongly attracted by males of large size.41 hhe well-known veterinary Blaine states43 that his own jhtQale pug became so attached to a spaniel, and a 'J1Hale setter to a cur. that in neither case would they jhbr with a dog of their own breed until several weeks lad elapsed. Two similar and trustworthy accounts laVe been given me in regard to a female retriever Urid a spaniel, both of which became enamoured with
terrier-dogs.
hlr. Cupples informs me that he can personally vouch 0r the accuracy of the following more remarkable case, 111 which a valuable and wonderfully-intelligent female terrier loved a retriever, belonging to a neighbour, to 8,1ck a degree that she had often to be dragged away teonx him. After their permanent separation, although lepeatedly shewing milk in her teats, she would never ^knowledge the courtship of any other dog, and to the legret of her owner, never bore puppies. Mr. Cupples ^so states that a female deerhound now (1868) in his vennel has thrice produced puppies, and on each j^Pasion shewed a marked preference for one of the jtegest and handsomest, but not the most eager, of four *teer-hounds living with her, all in the prime of life, . Cupples has observed that the female generally tevours a dog whom she has associated with and 'Rows ; her shyness and timidity at first incline her gainst a strange dog. The male, on the contrary, s eras rather inclined towards strange females. It appears to be rare when the male refuses any par- ticular female, but Mr. Wright, of Yeldersley House,
, " •* Dogs : their Management,’ by E. Mayliew, M.R.C.V.S., 2nd edit. p. 187-192.
* Quoted by Alex. Walker ‘Oh Intermarriage/ 1838, p. 276, see
"ho p. 244.
272
SEXUAL SELECTION: MAMMALS.
Pab'I'
It
a great breeder of clogs, informs me that he has lnioWJJ some instances ; he cites the case of one of his ofl'P deer-hounds, who would not take any notice of a paT' ticular female mastiff, so that another deer-hound had to be emjjloyed. It would be superfluous to give other cases, and I will only add that Mr. Bari', who lias car*-'” fully bred many blood-hounds, states that in almost every instance particular individuals of the opposhe sex shew a decided preference for each other, hi nail.' Mr. Cupples, after attending to this subject for another year, has recently written to me, “ I have had full con' “ firmation of my former statement, that dogs in breed' ‘ring form decided preferences for each other, bein? “ often influenced by size, bright colour, and individu*1' “ character, as well as by the degree of their previouS “ familiarity.”
In regard to horses, Mr. Blenkiron, the greatest breeder of race-horses in the world, informs me th» * stallions are so frequently capricious in their choice rejecting one mare and. without any apparent ca«s® taking to another, that various artifices have to b0 habitually used. The famous Monarque, for instant would never consciously look at the dam of Gladiateu1'- and a trick bad to be practised. We can partly see td 1 1 reason why valuable race-horse stallions, which are 1° such demand, should be so particular in their choice* Mr. Blenkiron has never known a mare to reject horse; but this has occurred in Mr. Wright’s stably so that the mare had to be cheated. Prosper Lucas4 quotes various statements from French authorities, and remarks, “ On voit des etalons qui seprennent d’u110 “jument, et negligent toutes les autres.” He gives, 0,1 the authority of Baelen, similar facts in regard to bull®*
43 * Traite tie l’Hered. Nat.’ tom. ii. 1850, p. 286.
UiiAp. XVII.
PREFERENCES IN PAIRING.
273
in describing tbe domesticated reindeer of says, “Foemina majores et fortiores mares Pr® cmteris admittunt, ad eos confugiunt, a juniori- agitate, qui lios in fugam conjiciunt.” 44 A clergy- ^Utn, who has bred many pigs, assures me that sows °ften reject one boar and immediately accept another.
I1 rom these facts there can be no doubt that with ril°st of our domesticated quadrupeds strong individual ^tipathies and preferences arc frequently exhibited yiul much more commonly by the female than by the ^ale. This being the case, it is improbable that the Elions of quadrupeds in a state of nature should be Jpt to mere chance. It is much more probable that 4e females are allured or excited by particular males, 'vl>o possess certain characters in a higher degree than °ther males ; but what these characters are, wo can SeUom or never discover with certainty.
14 ‘ Amoenitates Acad.’ vol. iv. 1788, p. 160.
Hoffberg,
upland.
V°L. II.
T
274
SEXUAL SELECTION: MAMMALS.
Part
II.
CHAPTER XVIII.
Secondary Sexcjal Characters of Mammals — continued-
Voice — Remarkable sexual peculiarities in seals — Odour — Deve' lopment ol tire hair — Colour of the hair and skin — AuoieV-^ case ol the female being more ornamented than the maleV Colour and ornaments due to sexual selection — Culour acq«irc‘ foi the sake ol protection — Colour, though common to sexes, often due to sexual selection — On the disappearance 0 spots and stripes in adult quadrupeds — On the colours :lJ,c ornaments of the Quadrnmana — Summary.
Quadrupeds use tlieir voices for various purpo^J, as a signal of danger, as a call from one member °[ a troop to another, or from the mother to her l°f offspring, or from the latter for protection to the'1' mother; but such uses need not here be considered H'e are concerned only with the difference between voices of the two sexes, for instance between that the lion and lioness, or of the bull and cow. all male animals use tlieir voices much more duri^ the rutting-season than at any other time ; and as the giraffe and porcupine,1 are said to be completed mute excepting at this season. As the throats (».«■ t'lC larnyx and thyroid bodies 2) of stags become period' cally enlaiged at the commencement of the breediIJb season, it might be thought that tlieir powerful vofc^ must be tlien in some way of high importance to then1* but this is very doubtful. Prom information give11 me by two experienced observers, Mr. McNeill and S‘r
1 Owen, ‘Anatomy of Vertebrates,’ vol. iii. p. 585.
Oil.
«*. XVIII.
VOCAL ORGANS.
275
■ Egerton, it seems tliat young stags under three ^ears old do not roar or bellow ; and that the old ones (legin bellowing at the commencement of the breeding- 8eason, at first only occasionally and moderately, whilst biey restlessly wander about in search of the females. J-heir battles are prefaced by loud and prolonged bel- owingj but during the actual conflict they are silent, finals of all kinds which habitually use their voices, l)tter various noises under any strong emotion, as when j^uraged and preparing to fight ; but this may merely 6 the result of their nervous excitement, which leads ^ the spasmodic contraction of almost all the muscles of body, as when a man grinds his teeth and clenches lls hands in rage or agony. ISio doubt stags challenge 6flch other to mortal combat by bellowing; but it is n°t likely that this habit could have led through b°XUal selection, that is by the loudest-voiced males ‘;tving been the most successful in their conflicts, to l(i periodical enlargement of the vocal organs ; for the ^ugs with the most powerful voices, unless at the same l,lle the strongest, best-armed, and most courageous, "puld not have gained any advantage over their rivals "ith weaker voices. The stags, moreover, which had "°aker voices, though not so well able to challenge other Stags, would have been drawn to the place of combat as Cfcl'tainly as those with stronger voices.
^ is possible that the roaring of the lion may be . , some actual service to him in striking terror into t‘ls adversary ; for when enraged he likewise erects his Qaile and thus instinctively tries to make himself ap- as terrible as possible. But it can hard.'y he sup- P°sed that the bellowing of the stag, even if it be of Jy service to him in this way, can have been im- jurtant enough to have led to the periodical enlarge- Some writers suggest that the
ll60t of the throat.
t 2
276
SEXUAL selection: mammals.
Part
II-
bellowing serves as a call to the female ; but th® experienced observers above quoted inform me tl'id female deer do not search for the male, though tbe males search eagerly for the females, as indeed nag'1* be expected from what we know of the habits ot other male quadrupeds. The voice of the feiusle’ on the other hand, quickly brings to her one or stags,3 4 as is well known to the hunters who in countries imitate her cry. If we could believe thlt the male had the power to excite or allure the feB>9^ by his voice, the periodical enlargement of his voc'1 organs would be intelligible on the principle of ses,ul selection, together with inheritance limited to the safl^ sex and season of the year ; but we have no evide»c® in favour of this view. As the case stands, the l°lU voice of the stag during the breeding season does »° seem to be of any special service to him, either dm'111' his courtship or battles, or in any other way. But 11,a-; we not believe that the frequent use of the voice, uvdet the strong excitement of love, jealousy, and rage, f°u tinued during many generations, may at last hi1' . produced an inherited effect on the vocal organs 0 the stag, as tvell as of other male animals? ^h1" appears to me, with our present state of knowledge the most probable view.
I ho male gorilla has a tremendous voice, and wh f adult is furnished with a laryngeal sack, as is like"’^ the adult male orang.* The gibbons rank amongst t noisiest of monkeys, and the Sumatra species ^
sjndactylus) is also furnished with a laryngeal sack _ 11 Mr. Blyth, who has had opportunities for observed011’
3 See, for instance. Major \V. Ross King (‘ The Sportsman in I860, p. 53, 131) on the habits of the moose and wild reindeer.
4 Owen, 1 Anatomy of Vertebrates/ vol. iii. p. 600.
c,ui>. xviii.
VOCAL 0 LiGANS.
277
floes not believe that the male is more noisy than the female. Hence, these latter monkeys probably use their v°ices as a mutual call; and this is certainly the case "‘th some quadrupeds, for instance with the beaver.5 Another gibbon, the H. agilis, is highly remarkable, fe°m having the power of emitting a complete and c°iTeet octave of musical notes,6 which we may reasonably Sl)spect serves as a sexual charm ; but I shall have to d-'ciir to this subject in the next chapter. The vocal 0|'guns of the American Mycetes caraya are one-third Wgep in the male than in the female, and are wonder- felly powerful. These monkeys, when the weather is '"tom, make the forests resound during the morning and Evening with their overwhelming voices. The males fe-gin the dreadful concert, in which the females, with their less powerful voices, sometimes join, and which 18 often continued during many hours. An excellent observer, llengger,7 could not perceive that they were exoited to begin their concert by any special cause ; he thinks that like many birds, they delight in their own 'dUsic, and try to excel each other. Whether most of the foregoing monkeys have acquired their powerful voices lri order to beat their rivals and to charm the females — °r whether the vocal organs have been strengthened
aild enlarged through the inherited effects of long-con- t'uued use without any particular good being gained P'1 will not. pretend to say; but the former view, at feast in the case of the Hylobate s agilis, seems the most
Probable.
I may here mention two very curious sexual pecu- harities occurring in seals, because they have been sup-
Mr. Green, in 1 Journal of Linn. Soc.’ vol. x. Zoology, 18G9, p. 3G2. 6 C. L. Martin, ‘ General Introduction to the Nat. liist. of Mamin, finals, ’ 1841, p. 431.
' Naturgeschicllte der Saugethiere von Paraguay,’ 1830, s. 15, 21.
27S
SEXUAL SELECTION : IIAMMALS.
PakT
II.
posed by some writers to affect the voice. The nose oi tiie male sea-elephant (Macrorhinus proboscideus), wbe® about three years old, is greatly elongated during tb e breeding-season, and can then be erected. In this state it is sometimes a foot in length. The female at J10 period of life is thus provided, and her voice is dif* ferent. That of the male consists of a wild, hoarse gurgling noise, which is audible at a great distant’ and is believed to be strengthened by the proboscis Lesson compares the erection of the proboscis, to the swelling of the Wattles of male gallinaceous birds, whilst they court the females. In another allied kind of sea1’ namely, the bladder-nose ( Cydophom cristata), the bea‘l is covered by a great hood or bladder. This is inter* nally supported by the septum of the nose, which ls produced far backwards and rises into a crest seveJ1 inches in height. The hood is clothed with short h^x> and is muscular; it can be inflated until it more th;lI) equals the whole head in size ! The males when ting light furiously on the ice, and their roaring “iS “ said to he sometimes so loud as to be heard f°ur
miles oft. M hen attacked by man they likewise r°lli or bellow ; and whenever .irritated the bladder is i°' flated. Some naturalists believe that the voice is th^ sti engthened, but various other uses have been assign®1 to this extraordinary structure. Mr. K. Brown thin1^ that it serves as a protection against accidents of 8,1 kinds. I his latter view is not probable, if what fbe sealers have long maintained is correct, namely) fba^ the hood or bladder is very poorly developed in females and in the males whilst young.®
8 0n tlle sea-elephant, see an article by Lesson, in ‘Diet. OsS' Hist. Nat. tom. xiii. p. 418. For the Cy&topkora or Stemmatop^ ^ Dr. Dekay, ‘ Annals of Lyceum of Nat. Hist. New York,’ vol. i. lS* ’ p. 94. Pennant lias also collected information from the sealers on ^
ODOUKS EMITTED.
279
C|JAP. XVIII.
Odour. — With some animals, as with the notorious skuuk of America, the overwhelming odour which they etQit appears to serve exclusively as a means of defence.
ith shrew-mice (Sorex) both sexes possess abdominal scent-glands, and there can be little doubt, from the banner in which their bodies aro rejected by birds and Jeasts of prey, that their odour is protective ; never- theless the glands become enlarged in the males during the breeding-season. In many quadrupeds the glands ai'e of the same size in both sexes;9 but their use is dot known. In other species the glands are confined t° the males, or are more developed in them than in the females ; and they almost always become more active during the rutting-season. At this period the Stands on the sides of the face of the male elephant Enlarge and emit a secretion having a strong musky °dour.
The rank effluvium of the male goat is well known, at)d that of certain male deer is wonderfully strong and persistent. On the banks of the Plata 1 have per- °eived the whole air tainted with the odour of the male Oervus campestris, at the distance of half a mile to Reward of a herd ; and a silk handkerchief, in which I carried home a skin, though repeatedly used and washed, h'tained, when first unfolded, traces of the odour for cue year and seven months. This animal does not emit ds strong odour until more than a year old, and if cas-
aiumal. The fullest account is given by Mr. Brown, who doubts about r^e rudimentary condition of the bladder in the female, in ‘ Proc. ^°°log. Soc.’ ISOS, p. 435.
8 As with the castoveum of the beaver, see Mr. L. H. Morgan’s interesting work, ‘ The American Beaver,’ lSGSi p. 300. Pallas 7 Spic. Zoolog.’ fasc. viii. 1770, p. 23) has well discussed the odoriferous glands of mammals. Owen Anat. of Vertebrates,’ vol. iii. p. 634) abo gives an account of these glands, including those of the elephant, at>d (p. 763) those of shrew-mice.
280
SEXUAL SELECTION: MAMMALS.
Part
II.
trated whilst young never emits it.10 Besides the general odour, with which the whole body of certain ruminant® seems to be permeated during the breeding-season, man,'' deer, antelopes, sheep, and goats, possess odoriferofl® glands in various situations, more especially on their iaees. The so-called tear-sacks or suborbital pits coin*' under this head. These glands secrete a semi-fl11'1* fetid matter, which is sometimes so copious as to stain the whole face, as I have seen in the case of an ante" lope. They are “ usually larger in the male than i’1 “ the female, and their development is checked by ca®* “ tration.” 11 According to Desmarest they are alto* gether absent in the female of Antilope sulgutturosa- Hence, there can be no doubt that they stand in son>e close relation with the reproductive functions. They are also sometimes present, and sometimes absent, nearly-allied forms. In the adult male musk-deer ( Moschus moschifervs), a naked spice round the tail is bedewed with an odoriferous fluid, whilst in the adult female, and in the male, until two years old, tbi® space is covered with hair and is not odoriferous. Tl*e proper musk-sack, from its position, is necessarily con* lined to the male, and forms an additional soent-orgfl®' It is a singular fact that the matter secreted by this latter gland does not, according to Pallas, change hi consistence, or increase in quantity, during the rutting* season; nevertheless this naturalist admits that its pi’e* sence is in some way connected with the act of repr°*
10 Eengger, ‘ Naturgeschichte dor Saugethiere von Paraguay,’
s. 355. 'I- his observer also gives some curious particulars in regard t° the odour emitted.
11 Owen, 1 Anatomy of Vertebrates,’ vol. iii, p. 632. See, also, Dr- Murie’s observations on their glands in ‘Proc. Zoolog. Soc.’ I*70’ p. 340. Desmarest, On the Antilope subgutturoea, • Mammalogie,’ 1S2°> p. 455.
C«AP. XVIII.
DEVELOPMENT OP HAIR.
281
Auction, He gives, however, only a conjectural and unsatisfactory explanation of its use.13
In most cases, when during the breeding-season the Unile alone emits a strong odour, this probably serves t:° excite or allure the female. We must not judge °n this head by our own taste, for it is well known that rats are enticed by certain essential oils, and cats by valerian, substances which are far from agree- able to us ; and that dogs, though they will not eat carrion, sniff and roll in it. From the reasons given "’hen discussing the voice of the stag, we may reject the idea that the odour serves to bring the females from a distance to the males. Active and long-continued cannot here have come into play, as in the case ot the vocal organs. The odour emitted must be ol con- siderable importance to the male, inasmuch as large and complex glands, furnished with muscles for evert- h'g the sack, and for closing or opening the orifice, have in some cases been developed. 1 he development cf these organs is intelligible through sexual selection, fr the more odoriferous males are the most successful in "'inning the females, and in leaving offspring to inherit their gradually-perfected glands and odours.
Development of the Hair. — We have seen that male Quadrupeds often have the hair on their necks and shoulders much more developed than in the females ; and many additional instances could be given. This s°metimes serves as a defence to the male during his battles; but whether the hair in most cases has been RPecially developed for this purpose is very doubtful. We may feel almost certain that this is not the case.
( 12 Pallas, ‘ Spicilegia Zoolog.’ fasc. xiii. 1799, p. .24 ; Desmoulins, * Diet. Class. d’Hist. Nat.’ tom. iii. p. 586.
282
Tart &
SEXUAL SELECTION: MAMMALS.
when a thin and narrow crest runs along the whole ength of the back; for a crest of this kind would afford scarcely any protection, and the ridge of the back is not a likely place to be injured ; nevertheless suck crests are sometimes conlined to the males, or are much more developed in them than in the female* wo antelopes, the Pragelaphus scriptus13 (see fig. p. 300) and Portax picta, may be given as instances- Ihe crests of certain stags and of the male wild goal stand erect, when these animals are enraged or terri- fied ; but it can hardly be supposed that they have been acquired lor the sake of exciting fear in their enemies. One of the above-named antelopes, the Pori 0 picta, has a large well-defined brush of black hair the throat, and this is much larger in the male than i» the. female. In the Ammotragus tragelaphus of North Africa, a member of the sheep-family, the front-leg3 are almost concealed by an extraordinary growth of hair, which depends- from the neck and upper halve3 oi the legs ; but Mr. Bartlett does not believe that this mantle is of the least use to the male, in whom it is much more developed than in the female.
Male quadrupeds of many kinds differ from the females in having more hair, or hair of a different character, on certain parts of their faces. The bul1 alone has curled hair on the forehead.15 In thre0 closely-allied sub-genera of the goat family, the maleS alone possess beards, sometimes of large size ; in t"° other sub-genera both sexes have a beard, but this
u ?r' iGran | Glelmin£S from the Menagerie at Knowsley,’ pi. 28- » Judge Catoa on the wapiti, ‘Transact. Ottawa Acid. ■!&*•
* 4°: B]yUl’ ‘L“d ^
‘5 ‘Himter’s Essays and Observations,’ edited by Owen, 1861, vol- 11
p. Zob. J
C[Up. XVIII.
DEVELOPMENT OP 1IAIE.
283
disappears in some of tlie domestic breeds of' the com- mon goat ; and neither sex of the Hemitragus has a beard. In the ibex the beard is not developed during the summer, and is so small at other seasons that it lriay be called rudimentary.16 With some monkeys the beard is confined to the male, as in the Orang, or is
Fig. 66. Plthecia Satanas, male (fault Bretmi).
Qmch larger in the male than in the female, as in the Mi/cetes caraya and Pitheeia satanas (lig. (50). So it is "ith the whiskers of some species of Macacus,11 and, as ■tve have seen, with the manes of some species of baboons.
16 See Dr. Gray’s ‘ Oat. of Mammalia in British Museum,’ part iii. 1852, p. 144.
17 Kengger, ‘ Saugethiere,’ &c., s. 14; Desmarest, ‘ Mammalogie,’ P. 66.
284
SEXUAL selection: mammals.
Part U*
Lut with most kinds of monkeys the various tufts of liaii about the face and head are alike in both sexes.
The males of various members of the Ox family (Lovidae), and of certain antelopes, are furnished with a dewlap, or great fold of skin on the neck, which is much less developed in the female.
Low', what must we conclude with respect to such sexual differences as these? .No one will ]>retend that the beards of certain male-goats, or the dewlap of the bull, or the crests of hair along the backs of certain male antelopes, are of any direct or ordinary use to them. It is possible that the immense beard of the male Pitheeia, and the large beard of the male Oraug- may protect their throats when fighting ; for the keepers in the Zoological Gardens inform me that many monkeys attack each other by the throat : but it is not probable that the beard has been developed for a distinct purpose from that which the whiskers, moustache, and other tufts of hair on the face serve ; and no one 'nil suppose that these are useful as a protection. Must we attribute to mere purposeless variability in the male all these appendages of hair or skin ? It cannot be de- nied that this is possible; for with many domesticated quadrupeds, certain characters, apparently not derived through reversion from any wild parent-form, have ap- peared in, and are confined to, the males, or are more largely developed in them than in the females,— for in- stance the hump in the male Zebu-cattle of India, the tail in hit-tailed rams, the arched outline of the forehead in the males ol several breeds of sheep, the mane in the ram of an African breed, and, lastly, the mane, long hairs on the binder legs, and the dewlap in the male alone of the Bcrbura goat.18 The mane which occurs in
18 See the chapters on these several animals in vol. i. of my ‘Vari- ation of Animals under Domestication;’ also vol. ii. p. T3 ■ also cliap. s*
C«AP. XVIII.
DEVELOPMENT OF HAIR.
285
the rams alone of the above-mentioned African breed of sheep, is a true secondary sexual character, for it is not developed, as I hear from Mr. Winwood Kendo, if the 'Rhinal be castrated. Although we ought to be ex- Keinely cautious, as shewn in my work on ‘ Variation Under Domestication,’ in concluding that any character, even with animals kept by semi-civiliscd people, has hot been subjected to selection by man, and thus aug- mented ; yet in the cases just specified this is im- probable, more especially as the characters are confined fo the males, or are more strongly developed in them than in the females. If it were positively known that the African ram with a mane was descended from the s*tme primitive stoclc with the other breeds of sheep, 0l' the JBerbura male-goat with his mane, dewlap, &c., k'om the same stock with other goats ; and if selee- t)on has not been applied to these characters, then they must be due to simple variability, together with sexually-limited inheritance.
In this ease it would appear reasonable to ex- tend the same view to the many analogous characters °ccurring in animals under a state of nature. Never- theless I cannot persuade myself that this view is applicable in many cases, as in that of the extraordi- nary development of hair on the throat and fore-legs °f the male Ammotragus, or of the immense beard of the male Pithecia. With those antelopes in which the niale when adult is more strongly-coloured than the tenrale, and with those monkeys in which this is like- wise the case, and in which the hair on the face is of a different colour from that on the rest of the head, being Arranged in the most diversified and elegant manner, *t seems probable that the crests and tufts of hair have
°u the practice of selection by semi-civilised people. For the Berbuva Seat, see Dr. Cray, ‘ Catalogue,’ ibid. p. 157.
2S6
SEXUAL SELECTION: MAMMALS.
Part ‘
been acquired as ornaments; and this I know is the opinion of some naturalists. If this view be correct, there can be little doubt that they have been acquired, or at least modified, through sexual selection.
Colour of the Hair and of the Nahed Shin. — I "'ill first give briefly all the cases known to me, of imde quadrupeds differing in colour from the females. With Marsupials, as I am informed by Mr. Gould, the sexes rarely differ in this respect; but the great red kan- garoo offers a striking exception, “delicate blue being “the prevailing tint in those parts of the female- “ which in the male are red.”19 In the Didelphis opos- sum of Cayenne the female is said to be a little more red than the male. With Rodents Dr. Gray remarks: “African squirrels, especially those found in the tropi' “ cal regions, have the fur much brighter and more “ vivid at some seasons of the year than at others, and “ the fur of the male is generally brighter than that “of the female.”20 Dr. Gray informs me that he specified the African squirrels, because, from their un- usually bright colours, they best exhibit this diffe,v enee. The female of the Mus minutus of Russia is a paler and dirtier tint than the male. In some f«" bats the fur of the male is lighter and brighter than in the female.21
The terrestrial Carnivora and Insectivora rarely eX' hibit sexual differences of any kind, and their colon are almost always exactly the same in both sexes. The
19 Osphranter rufn s, Gould. ‘Mammal- of Australia.’ vcl. ii. 18°3' On tlic Didelphis, D< smnrost, * Mumnmlogie,’ p. 250.
20 ‘Annals and Mag. of Nat. IIi»t.’ Nov. 1867, p.':l25. On the M*1 minutus, Desmarest, 1 Mammalogie,’ p, 604.
21 J- A. Allen, in ‘ Bulletin of Mus. Comp. Zoolog. of Cambridge- United States,’ ISO!), p. 207.
C«AP. XVIII.
ORNAMENTAL COLOURS.
287
°celot ( Felis pardalis), however, offers an exception, for ^le colours of the female, compared with those of the l^le, are “moms apparentes, le fauve etant plus terne, t blanc moins pur, les raies avant moius de largeur et les taehes moins de diametre.”22 The sexes of ^le allied FeUs mitis also differ, but even in a less degree, the general hues of the female being rather Paler than in the male, with the spots less black. Jlte marine Carnivora or Beals, on the other hand, s 01 ne times differ considerably in colour, and they pre- Sf;Tlt, as we have already seen, other remarkable sexual differences. Thus the male of the Otaria nigrescens °i the southern hemisphere is of a rich brown shade above; whilst the female, who acquires her adult tints eai’lier in life than the male, is dark-grey above, the young of both sexes being of a very deep chocolate Colour. The male of the northern Phoea groenlandica ls tawny grey, with a curious saddle-shaped dark mark 0Q the back ; the female is much smaller, and has a v®*y different appearance, being “dull white or yellow- tsh straw-colour, with a tawny hue on the back the ~ °ung at first are pure white, and can “ hardly be dis- ' tinguished among the icy hummocks and snow, their colour thus acting as a protection.” 23 With Ruminants sexual differences of colour occur t^ore commonly than in any other order. A difference this kind is general with the Strepsicerene antelopes ; the male nilghau ( Portax picta j is bluish-grey at|d much darker than the female, with the square white Patch on the throat, the white marks on the fetlocks,
." Desmarest, 1 Mamraalngie,’ 1820, p. 223. On Feliti mitie, Jtezagor, Dl‘'- s. 194.
p^Dr. Murie on the Otaria, ‘Proc. Zool. Soc.’ 1863, p. 108. Hr. (.kj Drown, on the P. groenlandica , ibid. 1868, p. 417. See also on the 0l°urs of seals, Desmarest, ibid. p. 213, 249,
288
sexual selection: mammals.
Part
and the black spots on the ears, all much more dis* tinet. We have seen that in this species the crests and tufts of hair are likewise more developed in the mad0 than in the hornless female. The male, as I am informed by Mr. Myth, without shedding his had-’ periodically becomes darker during the breeding-sea" son. Young males cannot be distinguished from youoS females until above twelve months old; and if d'e male is emasculated before this period, he never, accord- ing to the same authority, changes colour. The import' ance of this latter fact, as distinctive of sexual colouring becomes obvious, when we hear24 that neither the red summer-coat nor the blue winter-coat of the Virginia11 deer is at all affected by emasculation. With most or all of the highly-ornamented species of Tragelaphus tb0 males are darker than the hornless females, and thmr crests of hair are more fully developed. In the mal0 of that magnificent antelope, the Derbyan Eland, tbe body is redder, the whole neck much blacker, and tbe white baud which separates these colours, broaden than in the female. In the Cape Eland also, the mad0 is slightly darker than the female.26
In the Indian Mack-buck (A. Lezoarlica'), which belong’ to another tribe of antelopes, the male is very dark, alm°rt black; whilst the hornless female is fawn-coloured. ^ 1 meet in this species, as Mr. Blyth informs me, an exadj) similiar scries of facts, as with the Portax jncta, namely b1 the male periodically changing colour during the breed
24 Judge Caton, in ‘ Trans. Oltawa Acad, of Nat. Sciences,’ lSfiS’
p. d- 0.
25 Dr- Dray, ‘ Cat. of Mamm. in Brit. Mus.’ part iii. 1852, p. 134'1 ^ also Dr. Gray, ‘ Gleanings from the Menagerie of Knowsley,' in ^lu^ there is a splendid drawing of the Oreas derbianus : see the text u Tragelaphus. For the Cape Eland (Orens canna), see Andrew Bui1 ’
‘ Zoology of S. Africa,’ pi. 41 and 42. There are also many of me antelopes in the Zoological Society’s Gardens.
C»4P. XVIII.
ORNAMENTAL COLOURS.
289
season, in the effects of emasculation on this change, and in the young of both sexes being undistinguish- jl ) e from each other. In the Antilope mger the male is -* act, the female as well as the young being brown ; in j ' sing-sing the malo is much brighter coloured than the , 01’Lless female, and his chest and belly are blacker ; the male A. caama, the marks and lines which occur various parts of the body are black instead of as II' the female brown; in the brindled gnu (A. gorgon) (( ^IG colours of the male are nearly the same as those °f the female, only deeper and of a brighter hue.”26 frer analogous cases could be added, fhe Banteng bull ( Bos sondaicus ) of the Malayan 'l,,('hipelago is almost black, with white legs and but- °cks ; the cow is of a bright dun, as are the young ^ules until about the age of three years, when they frpidly change colour. The emasculated bull reverts . the colour of the female. The female Ivemas goat ls paler, and the female Capra segagrus is said to be ^°i'e uniformly tinted than their respective males, j eer rarely present any sexual differences in colour. Ul%e Caton, however, informs me that with the males 0 the Wapiti deer ( Germs Canadensis ) the neck, belly, 6ud legg are much darker than the same parts in the G)nale ; but during the winter the darker tints gradually j 0 away and disappear. I may here mention that ' udge Caton has in his park three races of the Yir- Sfrian deer, which differ slightly in colour, but the
erences are almost exclusively confined to the blue
sr 0tl the Ant. niger, Bee ‘Proc. Zool. Soc.’ 1S50, p. 133. With re- i,, ct *° an allied species, in which there is an equal sexual difference Po^nr, see Sir S. Baker, ‘ The Albert Nyauza,’ 1866, vol. ii. p. 327. hia] • f1' sin9-sin9i Gray, ‘ Cat. B. Mus.’ p. 100. Desmarest, ‘ Mam- a °gie,’ p. 468, on the A. caama. Andrew Smith, ‘Zoology of S.
TluV on the Gnu.
V°L. II. U
290
SEXUAL SELECTION: MAMMALS.
Pakt
it
winter or breeding coat ; so that this case may compared with those given in a previous chapter 0 closely-allied or representative species of bii’ds which differ from each other only in their nuptial plumage- The females of Cervus paludosus of S. America, well as the young of both sexes, do not possess tb e black stripes on the nose, and the blackish-brown l111® on the breast which characterise the adult males" Lastly, the mature male of the beautifully coloured spotted Axis deer is considerably darker, as I am formed by Air. Myth, than the female ; and this b11® the castrated male never acquires.
The last Order which we have to consider — for I iin‘ not aware that sexual differences in colour occur 111 the other mammalian groups — is that of the Primal' The male of the Lemur macaco is coal-black, wbnf the female is reddish-yellow, but highly variable colour.'29 Of the Quadrumana of the New World, ^ ,visb'
in-
females and vouiu
of Mycetes caraya are grey1 yellow and alike; in the second year the young 11111 becomes reddish-brown, in the third year black, cepting the stomach, which, however, becomes T1'1' black in the fourth or fifth year. There is als° strongly-marked difference in colour between the in Mycetes senicuhis and Cebus capucinus ; the y°ll)lr of the former and I believe of the latter species re sembling the females. With Pithecia leucocephcda ^ * young likewise resemble the females, which are brown13 1
27 1 Ottawa Academy of Sciences,’ May 21, 1808, p. 3, 5.
22 S. Muller, on the Bnnteng, « Zoog. Indischen Archipel.’ 1839:1- , , tab. 35 : see also Baffles, as quoted by Mr. Blytb, in ‘Land and W1*1^ 1867, p. 476. On goats, Dr. Gray, ‘Cat. Brit. Mus.’ p. 146; Desniim ; ‘ Mammalogie, p. 482. On the Cervus paludosus, Rcngger, ibid. s. „ 29 Sclater, ‘ Proc. Zool. Soc.’ 1866, p. 1. The same fact has also > fidly ascertained by MM. Pollen and van Dain.
ClIAP. XVIII.
ORNAMENTAL COLOURS.
291
■’tack above and light rusty-red beneath, the adult tllales being black. The ruff of hair round the face Ateles marginatus is tinted yellow in the male and "kite in the female. Turning to the Old World, the ^ales of Hylobates hoolodk are always black, with the exception of a white band over the brows ; the females 'ary fx-om whity-brown to a dark tint mixed with Hack, but are never wholly black,30 In the beautiful . ercopithecus diana the head of the adult male is of an ‘''tense black, whilst that of the female is dark grey ; in le former the fur between the thighs is of an elegant ."Wn-eoloirr, in the latter it is paler. In the equally dutiful and curious moustache monkey (Cercojoithecus Cephus) the only difference bet ween the sexes is that le tail of the male is chesnut and that of the female pey ; but Mr. Bartlett informs me that all the hues J°come more strongly pronounced in the male when *"mlt, whilst in the female they remain as they were j Ul’ing youth. According to the coloured figures given y Solomon Muller, the male of Semnopiihecus chry- °0,ne?aS is nearly black, the female being pale brown. 11 the Cercopithec'us cynosurus and griseo-viridis one j!ai't of the body which is confined to the male sex is of 'e most brilliant blue or green, and contrasts strikingly "fill the naked skin on the hinder part of the body, "nich is vivid red.
Lastly, in the Baboon family, the adult male of Cyno- ?e- phalus hamadryas differs from the female not only by ls immense mane, but slightly in the colour of the hair Utlk of the naked callosities. In the drill ( OynoeepJialus
leb° 9n Myoetes’ Rengger, ibid. 8. 14; and Brehm, ‘ Illustrates Thier- 0 e’t i. a. 96, 107. On Ateles, Desmarest, ‘ Mammalogie,’ ]). 75. ■jj., hylobates, Blyth, 1 Land and Water,’ 1807, p. 135. On the Semno- e°ns, g. Midler, ‘Zoog. ludischen Arcbipel.’ tab. x.
u 2
2!)2 SEXUAL SELECTION: MAMMALS. PaktI1-
leucojilueus) the females and young are much pale1' coloured, with less green, than the adult males. ^ other member of the whole class of mammals is colour^ in so extraordinary a manner as the adult male mandril (Gynocejohalm mormon). The face at this age become" of a fine blue, with the ridge and tip of the nose of most brilliant red. According to some authors the &ce is also marked with whitish stripes, and is shaded in pa1*5
Fig. 67. Heart of male Mandrill (from Gervais, ‘ Hist. Nat. des Mammife«3
with black, but the colours appear to be variable. ^ the forehead there is a crest of hair, and on the chi*1 ‘
RHAP. XVIII. ORNAMENTAL COLOURS. 293
yellow beard. “ Toutes les parties superieures de leurs euisses et le grand espace nu de leurs fesses sont ' egalement colores du rouge le plus vif, avec un melange de bleu qui ne manque reellement, pas 1 ^ elegance.” 31 When the animal is excited all the naked parts become much more vividly tinted. Several authors have used the strongest expressions in describing these resplendent colours, which they compare with those of Hre most brilliant birds. Another most remarkable Peculiarity is that when the great canine teeth are fully developed, immense protuberances of bone are formed °n each cheek, which are deeply furrowed longitudinally, arid the naked skin over them is brilliantly-coloured, as •i’rst described. (Fig. G7.) In the adult females and in lire young of both sexes these protuberances are scarcely Perceptible ; and the naked parts are much less brightly Coloured, the face being almost black, tinged with blue. 1 n the adult female, however, the nose at certain regular rtrtervals of time becomes tinted with red.
In all the cases hitherto given the male is more strongly or brightly coloured than the female, and dif- I'Ts in a greater degree from the young of both sexes, ll'it as a reversed style of colouring is characteristic of Urn two sexes with some few birds, so with the Rhesus donkey ( Maeacus rhesus) the female has a large surface °f naked skin round the tail, of a brilliant carmine red, "Pick periodically becomes, as I was assured by the Peepers in the Zoological Gardens, even more vivid, and her face is also pale red. On the other hand with
!1 Gervais, 1 Hist. Nat. des Mammif eres,’ 1851, p. 103. Figures aro S'ven of the skull of the male. Desmarest, ‘ Mammalogie,’ p. 70. Geofiroy St.-Hilaire and F. Cuvier, ‘ Hist. Nat. des Mamm.’ 1821, tom. i.
294
SEXUAL SELECTION : MAMMALS.
Pakt
It
the adult male and with the young of both sexes, as I saw in the Gardens, neither the naked skin at the posterior end of the body, nor the face, shew a trace of red. It appears, however, from some published accounts, that the male does occasionally, or during certain seasons, exhibit some traces of the red. Although he is thus less ornamented than the female, yet in the larger size of his body, larger canine teeth, more de- veloped whiskers, more prominent superciliary ridgeS> he follows the common rule of the male excelling the female.
I have now given all the cases known to me of a dif- ference in colour between the sexes of mammals. Tke colours of the female either do not differ in a sufficient degree from those ot the male, or are not of a suitable nature, to afford her protection, and therefore cannot h« explained on this principle. In some, perhaps in many cases, the differences may he the result of variation13 confined to one sex and transmitted to the same »eS> without any good having been thus gained, and there- fore without the aid of selection. We have instances ol this kind with our domesticated animals, as in tb® ma es ol certain cats being rusty-red, whilst the fernaleS are tortoise-shell coloured. Analogous cases occur under nature ; Mr. Bartlett has seen many black var- ieties ot the jaguar, leopard, vulpine phalanger aD( wombat ; and he is certain that all, or nearly all, "'el’e males. On the other hand, both sexes of wolve3’ foxes, and apparently of American squirrels, are occa- sionally born black. Hence it is quite possible that with some mammals the blackness of the males, especi- ally w hen this colour is congenital, may simply be th® result, without the aid of selection, of one or nior® variations having occurred, which from the first "’ere
Chap. XVIII.
ORNAMENTAL COLOURS.
295
sexually limited in their transmission. Nevertheless d can hardly he admitted that the diversified, vivid, and contrasted colours of certain quadrupeds, for in- stance of the above-mentioned monkeys and antelopes, can thus be accounted for. We should bear in mind that these colours do not appear in the male at birth, as in the case of most ordinary variations, but only at °p near maturity ; and that unlike ordinary variations, h' the male be emasculated, they never appear or sub- sequently disappear. It is on the whole a much more probable conclusion that the strongly-marked colours ilud other ornamental characters of male quadrupeds nre beneficial to them in their rivalry with other males, and have consequently been acquired through sexual ^election. The probability of this view is strengthened by the differences in colour between the sexes occur- ring almost exclusively, as may be observed by going through the previous details, in those groups and sub- groups of mammals, which present other and distinct secondary sexual characters ; these being likewise due i° the action of sexual selection.
Quadrupeds manifestly take notice of colour. Sir 8. Baker repeatedly observed that the African elephant and rhinoceros attacked with special fury white or grey borses. I have elsewhere shewn32 that half-wild horses apparently prefer pairing with those of the same colour, and that herds of fallow-deer of a different colour, though living together, have long kept distinct. It is a more significant fact that a female zebra would not admit the addresses of a male ass until ho was painted so as to resemble a zebra, and then, as John Hunter remarks, “ she received him very readily. In this curious fact,
32 ‘ The Variation of Animals and Plants under Domestication,’ 1868, v°l- ii. p. 102, 103.
296
SEXUAL SELECTION : MAMMALS.
Part fl*
“ we Ilavc instinct excited by mere colour, which had “so strong an effect as to get the better of ever)" “ thing else. But the male did not require this, the “ female being an animal somewhat similar to himself, “ "’as sufficient to rouse him.”33 In an early chapter we have seen that the mental powers of the higher animals do not differ in hind, though so greatly in degree, from the corresponding powers of man, especially of the lower and barbarous races; and it would appear that even their taste for the beautiful is not widely different from that of the Quad- rumana. As the negro of Africa raises the flesh on his face into parallel ridges “ or cicatrices, high above the “natural surface, which unsightly deformities, are con- “ 8ldered great personal attractions;”34— as negroes, as well as savages in many parts of the world, paint their laces with red, blue, white, or black bars,— so the male mandrill of Africa appears to have acquired his deeply-furrowed and gaudily. coloured face from having- been thus rendered attractive to the female. No doubt it is to us a most grotesque notion that the posterior end of the body should have been coloured for the sake of ornament even more brilliantly than the face! but this is really not more strange than that the tails of many birds should have been especially de- With mammals we do not at present possess any evi- dence that the males fake paius to display their charms ie ore t le female ; and the elaborate manner in which this is performed by male birds, is the strongest argu- ment in favour of the belief that the females admire,
“‘Essays and Observations by J. Hunter,’ edited by Owen, 186b yol. i. p. 194. J
Sir S. Baker, ‘ The Nile Tributaries of Abyssinia,’ 1867.
CHAP. XVIII.
EQUAL TRANSMISSION.
297
°r are excited by, the ornaments and colours displayed before them. There is, however, a striking parallelism between mammals and birds in all their secondary sexual characters, namely in their weapons for lighting with rival males, in their ornamental appendages, and in their colours. In both classes, when the male differs from the female, the young of both sexes almost always resemble each other, and in a large majority of cases resemble the adult female. In both classes the male assumes the characters proper to his sex shortly before the age for reproduction ; if emasculated he either never acquires such characters or subsequently loses them. In both classes the change of colour is sometimes seasonal, and the tints of the naked parts sometimes become more yivid during the act of courtship. In both classes the ’"ale is almost always more vividly or strongly coloured than the female, and is ornamented with larger crests cither of hair or feathers, or other appendages. In a tew exceptional cases the female in both classes is 'Lore highly ornamented than the male. With many Mammals, and at least in the case of one bird, the U|ale is more odoriferous than the female. In both classes the voice of the male is more powerful than that °t the female. Considering this parallelism there can be tittle doubt that the same cause, whatever it may he, bas acted on mammals and birds ; and the result, as far 88 ornamental characters are concerned, may safely be attributed, as it appears to me, to the loug-continued preference of the individuals of one sex for certain in- dividuals of the opposite sex, combined with their suc- cess in leaving a larger number of offspring to inherit Iheir superior attractions.
Equal transmission of ornamental characters to both sexes. — With many birds, ornaments, which analogy leads
298
SEXUAL SELECTION : MAMMALS.
Part II-
us to believe were primarily acquired by tbe males, have been transmitted equally, or almost equally, to both sexes ; and we may now enquire how far this vie"' may be extended to mammals. With a considerable number of species, especially the smaller kinds, both sexes have been coloured, independently of sexual selec- tion, for the sake ot protection ; but not, as far as I can judge, in so many cases, nor in nearly so striking a manner as in most of the lower classes. Audubon re* marks that he often mistook the musk-rat,35 whilst sitting on the banks of a muddy stream, for a clod of earth, so complete was the resemblance. The hare on her form is a familiar instance ot concealment through colour ’ yet this principle partly fails in a closely-allied species, namely the rabbit, for as this animal runs to its burro"', it is made conspicuous to the sportsman and no doubt to all beasts of prey, by its upturned pure-white tail- No one has ever doubted that the quadrupeds which inhabit snow-clad regions, have been rendered white to protect them from their enemies, or to favour their stealing on their prey. In regions where snow never lies long on the ground a white coat would be inju' lious ; consequently species thus coloured are extremely rare in the hotter parts of the world. It deserves notice that many quadrupeds, inhabiting moderately cold re* gions, although they do not assume a white winter dress, become paler during this season ; and this apparently' is the direct result of the conditions to which they have long been exposed. Pallas36 states that in Sibe- ria a change of this nature occurs with the wolf, two species ol Alustela, the domestic horse, the Equus
3j Filer zibelMcus , Audubon and Bachman. ‘The Quadrupeds of
X. America,* 18-16, p. 109.
30 ‘Novso species Quadrupedum e Glirium ordine,* 1778, p. 7. Wh** I have called the roe is the Capreolus Sibiricus subecauclatus of Pallas.
Chap. XVIII.
EQUAL TRANSMISSION.
299
7nionus, the domestic cow, two species of antelopes, the ®usk-deer, the roe, the elk, and reindeer. The roe, for instance, has a red summer and a greyish-white winter coat; and the latter may perhaps serve as a protection to the animal whilst wandering through the leafless thickets, sprinkled with snow and hoar-frost, it the above named animals were gradually to extend their range into regions perpetually covered with snow, their pale winter-coats would probably be rendered, through natural selection, whiter and whiter by de- grees, until they became as white as snow.
Although we must admit that many quadrupeds have received their present tints as a protection, yet with a host of species, the colours are far too conspicuous and too singularly arranged to allow us to suppose that they serve for this purpose. We may take as an illustra- tion certain antelopes: when we see that the square White patch on the throat, the white marks on the fet- locks, and the round black spots on the ears, are all "lore distinct in the male of the Portax picta, than in the female ; — when we see that the colours are more Avid, that the narrow white lines on the flank and tlie broad white bar on the shoulder are more distinct "i the male Oreas Derlyanus than in the female ; — when we see a similar difference between the sexes °i the curiously-ornamented Tragelaphus scriptus (fig.
68), we may conclude that these colours and various
"larks have been at least intensified through sexual election. It is inconceivable that such colours and "larks can be of any direct or ordinary service to these animals; and as they have almost certainly been inten- sified through sexual selection, it is probable that they Were originally gained through this same process, and 'hen partially transferred to the females. If this view he admitted, there can be little doubt that the equally
300 SEXUAL SELECTION: MAMMALS. Part H-
singular colours and marks of many other antelopes, though common to both sexes, have been gained and transmitted in a like manner. Both sexes, for instance, ot the Koodoo (Strepsiceros Kudu, fig. 02) have nar-
I' lg. OS. Tragelaphus script™, male (from the Knowsley Menagerie),
row white vertical lines on their hinder flanks, and an elegant angular white mark on their foreheads. Both sexes in the genus Damalis are very oddly coloured ; hi D. pygarga the back and neck are purplish-red, shading on the flanks into black, and abruptly separated from the
Chap. XVIII. EQUAL TRANSMISSION. 301
white belly and a large white space on the buttocks ; the head is still more oddly coloured, a large oblong- white mask, narrowly-edged with black, covers the face Up to the eyes (fig. 69) ; there are three white stripes on the forehead, and the ears are marked with white. The fawns of this species are of a uniform pale yellow-
>'ig. 09. Diumilia jijgarga, male (from the Knowsley Menagerie).
ish-brown. In Damalh albifrons the colouring of the head differs from that in the last species in a single white stripe replacing the three stripes, and in the ears being almost wholly white.37 After having studied to
37 See the fine plates in A. Smith’s ‘ Zoology of S. Africa,’ and Dr. Gray’s ‘ Gleanings from the Menagerie of Knowsley.’
302
SEXUAL SELECTION : MAMMALS.
Part li-
the best of my ability the sexual differences of animals belonging to all classes, I cannot avoid the conclusion that the curiously-arranged colours of many antelopes* though common to both sexes, are the result of sexual selection primarily applied to the male.
The same conclusion may perhaps be extended to the tiger, one of the most beautiful animals in the world, the sexes of which cannot be distinguished by colour, even by the dealers in wild beasts. Mr. Wallace believes 33 that the striped coat of the tiger “ so assi' “ milates with the vertical stems of the bamboo, as to ‘‘ assist greatly in concealing him from his approaching prey. But this view does not appear to me satisfac- tory. We have some slight evidence that his beauty may be due to sexual selection, for in two species of Felis analogous marks and colours are rather brighter m the male than in the female. The zebra is conspic- uously striped, and stripes on the open plains of South Africa cannot afford any protection. Burchell 39 in de- scribing a herd says, “their sleek ribs glistened in the “ SUD’ and tlie brightness and regularity of their striped “ c°ats presented a picture of extraordinary beauty, i»
“ which probably they are not surpassed by anv other quadruped.” Here we have no evidence of ' sexual selection, as throughout the whole group of the Equidm the sexes are identical in colour. Nevertheless he who attributes the white and dark vertical stripes on the hanks ol various antelopes to sexual selection, will pro- bably extend the same view to the Royal Tiger and beautiful Zebra. °
We have seen in a former chapter that when young animals belonging to any class follow nearly the same
38 t
39 t
Westminster Review,’ July l, 1867 p 5 Travels in South Africa,’ 1S24, vol.’ii.' p. 315.
C«AP. XVIII.
SPOTS AND STRIPES.
303
habits of life with their parents, and yet are coloured 111 a different manner, it may be inferred that they have retained the colouring of some ancient and extinct Progenitor. In the family of pigs, and in the genus h'apir, the young are marked w ith longitudinal stripes, aud thus differ from every existing adult species in these two groups. With many kinds of deer the young are marked with elegant white spots, of which their parents exhibit not a trace. A graduated series can be followed from the Axis deer, both sexes of "'hick at all ages and during all seasons are beau- tifully spotted (the male being rather more strongly coloured than the female) — to species in which neither the old nor the young are spotted. I will specify some of the steps in this series. The Mantclmrian deer ( Cervus Manic) 'turicus) is spotted during the whole year, but the spots are much plainer, as I have seen Hi the Zoological Gardens, during the summer, when the general colour of the coat is lighter, than during the "’inter, when the general colour is darker and the horns are fully developed. In the hog-deer ( Hyelaplius por- cinus) the spots are extremely conspicuous during the summer when the coat is reddish-brown, but quite dis- appear during the winter when the coat is brown.40 dn both these species the young are spotted. In the Virginian deer the young are likewise spotted, and about five per cent, of the adult animals living in Judge Gaton’s park, as I am informed by him, tem- porarily exhibit at the period when the red summer coat is being replaced by the bluish winter coat, a row °f spots on each flank, which are always the same in
10 Dr. Gray, ‘ Gleanings from the Menagerie of Knowsley,’ p. 64. Mr. Blyth, in speaking (‘ Land and Water,’ 1863, p. 42) of the hog- "eer of Ceylon, says it is more brightly spotted with white than the ooannon liog-deer, at the season when it renews its horns.
•'U4 SEXUAL SELECTION: MAMMALS. Pabt II.
number, though very variable in distinctness. From this condition there is hut a very small step to the complete absence of spots at all seasons in the adults; and lastly, to their absence at all ages, as occurs with certain species. From the existence of this perfect series, and more especially from the fawns of so many species being spotted, we may conclude that the now living members of the deer family are the descendants of some ancient species which, like the Axis deer, was spotted at all ages and seasons. A still more ancient progenitor probably resembled to a certain extent the Hyomoschus aquaticus— for this animal is spotted, and the hornless males have large exserted canine teeth) of which some few true deer still retain rudiments. It offers, also, one of those interesting cases of a form linking together two groups, as it is intermediate in certain osteological characters between the pachyderms and ruminants, which were formerly thought to be quite distinct.41
A curious difficulty here arises. If we admit that coloured spots and stripes have been acquired as orna- ments, how comes it that so many existing deer, the descendants of an aboriginally spotted animal, and all the species of pigs and tapirs, the descendants of an aboriginally striped animal, have lost in their adult state their former ornaments ? I cannot satisfactorily answer this question. We may feel nearly sure that the spots and stripes disappeared in the progenitors of our existing species at or near maturity, so that they were retained by the young and, owing to the lawof inheritance at corresponding ages, by the young of all succeeding generations. It may have been a great advantage to
41 Falconer and Cautley, ‘ Proc. Geolog. Soc.’ 1813 ; and Falconer’s 1 Pal. Memoirs,’ vol. i. p. 196,
CHAP. XVIII.
SPOTS AND STRIPES.
305
the lion and puma from the open nature of the localities "'hi ch they commonly haunt, to have lost their stripes, a'id to have been thus rendered less conspicuous to their Prey ; and if the successive variations, by which this 6nd was gained, occurred rather late in life, the young "'ould have retained their stripes, as we know to be the case. In regard to deer, pigs, and tapirs, Fritz Muller has suggested to me that these animals by the removal through natural selection of their spots or stripes would have been less easily seen by their enemies ; and they "'ould have especially required this protection, as soon a« the carnivora increased in size and number during the Tertiary periods. This may be the true explana- tion, but it is rather strange that the young should »ot have been equally well protected, and still more strange that with some species the adults should have ’'stained their spots, either partially or completely, during part of the year. We know, though we cannot explain the cause, that when the domestic ass varies and becomes reddish-brown, grey or black, the stripes on the shoulders and even on the spine frequently disappear. Very few horses, except dun-coloured kinds, exhibit 8tripes on any part of their bodies, yet we have gopd reason to believe that the aboriginal horse was striped °n the legs and spine, and probably on the shoulders.42 htence the disappearance of the spots and stripes in our adult existing deer, pigs, and tapirs, may be due to a change in the general colour of their coats ; but whether this change was effected through sexual or natural se- lection, or was due to the direct action of the conditions °f life, or some other unknown cause, it is impossible llJ decide. An observation made by Mr. Sclater well dlustrates our ignorance of the laws which regulate the
12 ‘ The Variation of Animals and Plants under Domestication,’ l868, vol. i. p. 61-64.
VOL. II.
X
306
SEXUAL SELECTION : MAMMALS.
Part H.
appearance and disappearance of stripes ; the species of Asinus which inhabit the Asiatic continent are destitute of stripes, not having even the cross shoulder-stripe, whilst those which inhabit Africa are conspicuously striped, with the partial exception of A. tmniopus, which has only the cross shoulder-stripe and generally sonic taint bars on the legs ; and this species inhabits the almost intermediate region of Upper Egypt and Abyssinia.43
Quadrumana. — Before we conclude, it will be advis' able to add a few remarks to those already given on the
l ifi. 70. Head of Senmopfflwens rubkmndus. This and the fottowi, a figures (fr0"* i’rof. Gervais) are given to shew the odd arrangement ami development of the hair on the head.
*3 ‘Proc. Zool. Soc.’ 1862, p. 164. See, also, Dr. Hartmann, ‘ A»°- cl. Landw.’ Bd. xliii. s. 222.
c«Ap. XVIII.
QUADKUMANA.
307
ornamental characters of monkeys. In most of the 8Pecies the sexes resemble each other in colour, but 111 some, as we have seen, the males differ from the tamales, especially in the colour of the naked parts of the skin, in the development of the beard, whiskers, and mane. Many species are coloured either in so ex-
71. Head of Semnopithocus oomatus. Fig. 72. Head of Cebus capucinus.
traordinary or beautiful a man mu, and are furnished 'V)th such curious and elegant crests of hair, that we o^n hardly avoid looking at these characters as having been gained for the sake of ornament. The accom- panying figures (figs. 70 to 74) serve to shew the
Fig- 73.
Head of A teles marginatus.
Fig. 74. Head of Cebus vellerosus.
SEXUAL SELECTION: MAMMALS.
Part II*
:;os
airangement of the hair on the face and head in several species. It is scarcely conceivable that these crests of hair and the strongly-contrasted colours of the fur and skin can be the result of mere variability without the aid of selection ; and it is inconceivable that they can be of any ordinary use to these animals. If so, they have probably been gained through sexual selection, though transmitted equally, or almost equally, to both sexes. With many of the Quadrumana, we have addi- tional evidence of the action of sexual selection in the greater size and strength of the males, and in the greater development of their canine teeth, in comparison with the females.
With respect to the strange manner in which both sexes of some species are coloured, and of the beauty of others, a few instances will suffice. The face of the Cercopithecus petaurista (fig. 75) is black, the whiskers and beard being white, with a defined, round, white spot on the nose, covered with short white hair, which gives to the animal an almost ludicrous aspect. The Semnopithecus frontatus likewise, has a blackish face with a long black beard, and a large naked spot on the forehead of a bluish-white colour. The face of Macacus la&iotus is dirty flesh-coloured, with a defined ied spot on each cheek. The appearance of Cerco- cebus mtluops is grotesque, with its black face, white whiskers and collar, chesnut head, and a large naked white spot over each eyelid. In very many species, the beard, whiskers, and crests of hair round the face are of a different colour from the rest of the head, and when different, are always of a lighter tint,11 being often pure
" I observed this fact in the Zoological Gardens; and numerous cases may be seen in the coloured plates in Geoffroy St -Hilaire and E . Cuvier, < Hist. Nat. des Mammiferes,’ tom. i. 182-1.
f'iUP. SVIII. QUADRUMAJS’A. 309
'vhite, sometimes bright yellow, or reddish. The whole face of the South American Braohyurus calvus is of a “ glowing scarlet hue ; ” but this colour does not appear
Fig. Y5, Cercopitliecus petaurteta (from Brehm).
310
SEXUAL SELECTION : MAMMALS.
Part II-
until the animal is nearly mature.45 The naked skin of the face differs wonderfully in colour in the various species. It is often brown or flesh -colour, with parts pei feet]\ white, and often as black as that of the most sooty negro. Iu the Brachyurus the scarlet tint is brighter than that of the most blushing Caucasian t amsel. It is sometimes more distinctly orange than m any Mongolian, and in several species it is blue, passing into violet or grey. In all the species known to Mr. Bartlett, in which the adults of both .sexes have strongly-coloured faces, the colours are dull or absent during early youth. This likewise holds good with the Mandrill and Rhesus, in which the face and the posterior parts of the body are brilliantly coloured in one seX alone. In these latter cases we have every reason to believe that the colours were acquired through sexual selection ; and rve are naturally led to extend the same view to the foregoing species, though both sexes when adult have their faces coloured in the same manner.
Although, according to our taste, many kinds of monkeys are far from beautiful, other species are uni- ?e?sf' -v ^dmired ior their elegant appearance and nrigbt colours. The Semnopithecus nemeeus, though pceu nu y coloured, is described as extremely pretty! the orange-tinted face is surrounded by long whiskers o g ossy whiteness, with a line of chesnut-red over the eyebrows ; the fur on the back is of a delicate grey, with a square patch on the loins, the tail and the fore-arms a o a pine \\ lite ; a gorget of chesnut surmounts the chest; the hind thighs are black, with the legs chesnut- red. I will mention only two other monkeys on account of their beauty ; and 1 have selected these as they pre- sent slight sexual differences in colour, which renders it
40 Bates, 1 The Naturalist on the Amazons,’ 1863, vol. ii. p. 310.
c«ap. XVIII.
QUADRUMANA,
311
in some degree probable that both sexes owe their elegant appearance to sexual selection. In the mous- tache-monkey ( Cercopithecus cephus) the general colour of the fur is mottled-greenish, with the throat white ; in the male the end of the tail is chesnut; but the face is the most ornamented part, the skin being chiefly bluish- grey, shading into a blackish tint beneath the eyes, with the upper lip of a delicate blue, clothed on the lower edffe with a thin black moustache ; the whiskers
O
Cercopithecus Diana (from Brebm).
rig. 76.
312
sexual selection: mammals.
Part
are orange^coloured, with the upper partblack, forming a band which extends backwards to the ears, the latter being clothed with whitish hairs. In the Zoological Society’s Gardens I have often overheard visitors ad- miring the beauty of another monkey, deservedly called Cercopithecus Liana (fig. 76) ; the general colour of the iur is grey ; the chest and inner surface of the forc-legs are white ; a large triangular defined space on the hinder part of the back is rich ehesnut; in the male the inner sides of the thighs and the abdomen are delicate fawn- coloured,^ and the top of the head is black ; the face and ears are intensely black, finely contrasted with a white transverse crest over the eye-brows and with a long
white peaked beard, of which the basal portion is black.
In these and many other monkeys, the beauty and singular arrangement of their colours, and still more the diversified and elegant arrangement of the crests and tufts of hair on their heads, force the conviction on my nund that these characters have been acquired through sexual selection exclusively as ornaments.
Summary.— The law of battle for the possession of the female appears to prevail throughout the whole great class of mammals. Most naturalists will admit that the greater size, strength, courage, and pugnacity of the male, Ins special weapons of offence, as well as his special means of defence, have all been acquired or modified through that form of selection which I have
” Ilmve seen most of the above-named monkeys in the ZooIogical Society s Gardens. The description of the Semnopitheeus taken from Mr. W. C. Martin’s ‘Nat. Hist, of Mammalia,’ 1841, p. *60; see also p. 475, 528.
CHAP. XVIII.
SUMMARY.
called sexual selection. This does not depend on any Sl-ipci'ioi'ity in the general struggle for life, hut on certain individuals of one sex, generally the male sex, having been successful in conquering other males, and °n their having left a larger number of offspring to mherit their superiority, than the less successful males.
There is another and more peaceful kind of contest, hi which the males endeavour to excite or allure the females by various charms. This may be effected by ■he powerful odours emitted, by the males during the hreeding-season ; the odoriferous glands having been acquired through sexual selection. Whether the same vfew can he extended to the voice is doubtful, for the v°cal organs of the males may have been strengthened hy use during maturity, under the powerful excitements °1 love, jealousy, or rage, and transmitted to the same sex. Various crests, tufts, and mantles of hair, which ai'e either confined to the male, or are more developed 111 this sex than in the females, seem in most cases to he merely ornamental, though they sometimes serve as a defence against rival males. There is even reason to suspect that the branching horns of stags, and the efegant horns of certain antelopes, though properly serving as weapons of offence or of defence, have been partly modified for the sake of ornament.
When the male differs in colour from the female he generally exhibits darker and more strongly-contrasted ^nts. We do not in this class meet with the splendid ly,l. blue, yellow, and green colours, so common with jaale birds and many other animals. The naked parts, however, of certain Quadrumana must be excepted ; for 3Uc'h parts, often oddly situated, are coloured in some species in the most brilliant manner. The colours of the male in other cases may be due to simple variation,
314 SEXUAL SELECTION: MAMMALS. PART II-
without the aid of selection. But when the colours are diversified and strongly pronounced, when they are not developed until near maturity, and when they are 1°®* after emasculation, we can hardly avoid the conclusion that they have been acquired through sexual selection fer the sake of ornament, and have been transmitted exclu- sively, or almost exclusively, to the same sex. When both sexes are coloured in the same manner, and the colours are conspicuous or curiously arranged, without being of the least apparent use as a protection, and especially when they are associated with various other ornamental appendages, we are led by analogy to the same conclusion, namely, that they have been acquired through sexual selection, although transmitted to both sexes. That conspicuous and diversified colours, whether confined to the males or common to both sexes, are aS a general rule associated in the same groups and sub- groups with other secondary sexual characters, serving for war or for ornament, will be found to hold good it we look back to the various cases given in tbis and the last chapter.
4he law of the equal transmission of characters to both sexes, as far as colour and other ornaments are concerned, has prevailed far more extensively "ith mammals than with birds ; but in regard to weapon®’ such as horns and tusks, these have often been trans- mitted either exclusively, or in a much higher degi'ee to the males than to the females. This is a surprising circumstance, for as the males generally use then weapons as a defence against enemies of all kinds> these weapons would have been of service to the fe- male. Their absence in this sex can be accounted fob as far as we can see, only by the form of inheritance which has prevailed. Finally with quadrupeds tbe
°hap. XVIII.
SUMMARY.
315
contest between the individuals of the same sex, whether Peaceful or bloody, has with the rarest exceptions been confined to the males ; so that these have been mo- dified through sexual selection, either for fighting with each other or for alluring the opposite sex, far more commonly than the females.
316
SEXUAL SELECTION: MAN.
Past 11 •
CHAPTER XIX.
. Secondary Sexual Characters of Man.
Differences between man and woman — Causes of such differences and of certain characters common to both sexes — La"' oi battle — Differences in mental powers — and voice — On ^e influence of beauty in determining the marriages of manW11” Attention paid by savages to ornaments — Their ideas beauty in woman — 'J he tendency to exaggerate each nat11 1 ;l peculiarity.
With mankind the differences between the sexes are greater than in most species of Quadrumana, but »ot so great as in some, for instance, the mandrill. ^al‘ on an average is considerably taller, heavier, and stronger than woman, with squarer shoulders and W°re plainly-pronounced muscles. Owing to the relati°D which exists between muscular development and the projection of the brows,1 the superciliary ridge is geBe” rally more strongly marked in man than in wou>aB- His body, and especially his face, is more hairy, *u)d his voice has a different and more powerful tone. i 11 certain tribes the women are said, whether truly I kco" not, to differ slightly in tint from the men; and with Europeans, the women are perhaps the more bright!) coloured oi the two, as may be seen when both sexes have been equally exposed to the weather.
Man is more courageous, pugnacious, and energetic thau woman, and has a more inventive genius, i ^
1 Schaaffhausen, translation in 1 Anthropological Keview,’ Oct. I868,
p. 419, 420, 427.
Chap. XIX.
SEXUAL DIFFERENCES.
317
brain is absolutely larger, but whether relatively to the larger size of bis body, in comparison with that of 'voman, has not, I believe been fully ascertained. In "Oman the face is rounder ; the jaws and the base of the skull smaller ; the outlines of her body rounder, in parts more prominent; and her pelvis is broader than in man;2 but this latter character may perhaps be considered rather as a primary than a secondary sexual character. She comes to maturity at an earlier age than man.
As with animals of all classes, so with man, the dis- tinctive characters of the male sex are not fully deve- loped until he is nearly mature ; and if emasculated they never appear. The beard, for instance, is a secondary sexual character, and male children are beardless, though at an early age they have abundant hair on their heads. It is probably due to the rather late "Ppearance in life of the successive variations, by "hi eh man acquired his masculine characters, that they are transmitted to the male sex alone. Male and female children resemble each other closely, like the young of so many other animals in which the adult sexes differ ; they likewise resemble the mature female much more closely, than the mature male. The fe- male, however, ultimately assumes certain distinctive characters, and iu the formation of her skull, is said to be intermediate between the child and the man.3 Again, as tiie young of closely allied though distinct species do not differ nearly so much from each other as do the adults, so it is with the children of the different races of man. Some have even maintained that race-differences
2 Ecker, translation in ‘ Anthropological Review,’ Oct. 1868, p. 351- 356. The comparison of the form of the skull in men and women has been, followed out with much care by Welcker.
2 Ecker and Welcker, ibid. p. 352, 355 ; Yogt, ‘ Lectures on Man,’ ■®ng. translat. p. 81.
318
SEXUAL SELECTION: MAN.
Papa
II.
cannot be detected in the infantile skull.4 In regard to colour, the new-born negro child is reddish nut-brown, which soon becomes slaty-grey ; the black colour being fully developed within a year in the Sudan, but not until three years in Egypt. The eyes of the negro are at first blue, and the hair chesnut-brown rather than black, being curled only at the ends. The children of the Australians immediately after birth are yellowish- brown, and become dark at a later age. Those of the Gnaranys of Paraguay are whitish-yellow, but they acquire in the course of a few weeks the yellowish- brown tint of their parents. Similar observations have been made in other parts of America.5
I have specified the foregoing familiar differences be- tween the male and female sex in mankind, because they are curiously the same as in the Quadrumana. With these animals tho female is mature at an earlier age than the male; at least this is certainly the case with the Gelus azarw.6 With most of the species the males are larger and much stronger than the females, of which tact the gorilla offers a well-known instance. Even iu so trifling a character as the greater prominence oi the superciliary ridge, the males of certain monkeys diffel irom the females,7 and agree in this respect with man- kind. In the gorilla and certain other monkeys, the
-1 Scliaaffh arisen, ‘ Antliropolog. Beview,’ ibid. p. 429.
* pmner-ILy, on negro infants, as quoted by Vogt, ‘ Lectures o» Mali, Lug. translat, ISG4, p. 189 : for further facts on negro infant aS quoted from V\ interbottom and Oauiper, see Lawrence, ‘Lectures 0I* Physiology. &c. LS22, p. 451. Bor the infants of the Guaranys, tP‘ Kenggcr, ■ Siiugethiore,’ Ac. a. 3. See also Godron, ‘ Be TEspeoe,’ torn- ii. 1859, p. 253. For the Australians, Waltz, ‘ Inlroduct. to Ant‘u° pology,’ Eng. translat. 18G3, p. 99.
* Bengger, 1 Shugetliiere,’ Are. 1830, a. 49. ,
7 As in Maoacus cynomolgw (Desmarest, • Mammalogie,’ P- 631 n”
in Hyl abates agilis (Geoffrey St.-Hilaire and F. Cuvier, ‘Hist. Nat. c tD Mamm.’ 1824. tom. i. p. 2),
Chap. XIX.
SEXUAL DIFFERENCES.
319
cranium of the adult male presents a strongly-marked sagittal crest, which is absent in the female ; and Ecker found a trace of a similar difference between the two sexes in the Australians.8 With monkeys when there is any difference in the voice, that of the male is the 'Lore powerful. We have seen that certain male mon- keys, have a well-developed heard, which is quite de- ficient, or much less developed in the female. No in- stance is known of the beard, whiskers, or moustache being larger in a female than in the male monkey. Even in the colour of the beard there is a curious parallelism between man and the Quadmmana, for "'hen in man the beard differs in colour from the hair °f the head, as is often the case, it is, I believe, in- variably of a lighter tint, being often reddish. I have observed this fact in England, and Dr. Hooker, who attended to this little point for me in Russia, found "o exception to the rule. In Calcutta, Mr. J. Scott, °f the Botanic Gardens, was so kind as to observe with care the many races of men to be seen there, as well as in some other parts of India, namely, two races in Sikkim, the Bhoteas, Hindoos, Burmese, and Chinese. •Although most of these races have very little hair on fhe face, yet- he always found that when there was any difference in colour between the hair of the head and file beard, the latter was invariably of a lighter tint. Now "’itli monkeys, as has already been staled, the beard frequently differs in a striking manner in colour from fhe hair of the head, and in such cases it is invariably °f a lighter hue, being often pure white, sometimes yellow or reddish.9
8 ‘Anthropological Review,* Oct. 1858, p. 353.
a Mr. Blyth informs me that he lms never seen more than one instance °f the beard, whiskers, &e., in a monkey becoming white with old age, as is so eommouly the case with us. This, however, occurred in an aged
320
SEXUAL SELECTION: MAN.
Part U-
In regard to the general hairyness of the body, the women in all races are less hairy than the men, and i" some few Quadrumana the under side of the body ot the female is less hairy than that of the male.10 Lastly^ male monkeys, like men, are bolder and fiercer than the females. They lead the troop, and when there Is danger, come to the front. We thus see how close h the parallelism between the sexual differences of naan and the Quadrumana. With some few species, how- ever, as with certain baboons, the gorilla and orangt there is a considerably greater difference between the sexes, in the size of the canine teeth, in the develop" ment and colour of the hair, and especially in the colour of the naked parts of the skin, than in 'the case of mankind.
The secondary sexual characters of man are all highly variable, even within the limits of the same race or sub-species ; and they differ much in the several races, these two rules generally hold good throughout the animal kingdom. In the excellent observations mack on board the Novara ,n the male Australians were found to exceed the females by only G5 millim. in height) whilst with the Javanese the average excess was 21® millim., so that in this latter race the difference in height
and confined Macacus eynomolgus, whose moustaches were “remarkaW.' long and human-like.” Altogether this old monkey presented a lndicrouS resemblance to one of the reigning inorinrehs of Europe, after whom ne was universally nick-named. In certain races of man the hair on the head hardly ever becomes grey; thus Mr. I>. Forbes has never seen, as he informs me, an instance with the Aymaras and Quichuas oi S. America.
This is the ease with the females of several species of see Geoffroy St.-Hilaire and F. Cuvier, ‘Hist, Nat. des Mfunm.’ tom- 1- See, also, on K lar. ‘ Penny Encyclopedia,’ vol. ii. p. 149, 150.
11 The results were deduced by I)r. Weisbach from the measure- ments made by Drs. K. Selierzer and Schwarz, see ‘ Keise der Novara : Anthropolog. Theil,’ 1867, s. 216, 231, 234, 236, 239, 269.
Chap. XIX.
SEXUAL DIFFERENCES.
321
between the sexes is more than thrice as great as with the Australians. The numerous measurements of various other races, with respect to stature, the circumference of the neck and chest, and the length of the back-bone aod arms, which were carefully made, nearly all shewed that the males differed much more from each other than did the females. This fact indicates that, as far as these characters are concerned, it is the male which has been chiefly modified, since the races diverged from their common and primeval source.
The development of the beard and the hairiness of the body differ remarkably in the men belonging to distinct races, and even to different families in the same race. We Europeans see this amongst ourselves. In the island of St. Hilda, according to Martin,12 the men do not acquire beards, which are very thin, until the age of thirty or upwards. On the Europmo- Asiatic continent, beards prevail until we pass beyond India, though with the natives of Ceylon they are frequentlv absent, as was noticed in ancient times by Diodorus.13 Beyond India beards disappear, as with the Siamese, llalays, Kalmucks, Chinese, and Japanese; nevertheless the Amos,14 who inhabit the northernmost islands of the Japan archipelago, are the most hairy men in the world. With negroes the beard is scanty or absent, and they have 110 whiskers ; in both sexes the body is generally almost destitute of fine down.15 On the other hand, the Pa-
12 ‘ Voyage to St. Hilda’ (3rd edit. 1753) p. 37.
13 Sir J. E. Tennent, ‘ Ceylon,’ vol. it. 1859, p. 107.
14 Quatrefeges, ‘ Revue des Cours Soientifiques,’ Aug. 29, 1S68, p. 630 ; ’°gt, ‘ Lectures on Ma.n,’ Rug. translat. p. 127
t 15 On the beards of negroes, Vogt, ‘ Lectures,’ &c. ibid, p. 127 ; Waitz, lutroduct. to Anthropology,’ Engl, translat. 1863, vol. i. p. 96. It is remarkable that in the United Statis (‘Investigations in Military and Anthropological Statistics of American Soldiers,’ 1SC9, p. 569) the VOL. II. V
322
SEXUAL SELECTION : MAN.
Part II.
puans of the Malay archipelago, who are nearly as black as negroes, possess well-developed beards.16 In the Pacific Ocean the inhabitants of the Fiji archipelago have large bushy beards, whilst those of the not-distant archipelagoes of Tonga and Samoa are beardless ; but these men belong to distinct races. In the Ellice group all the inhabitants belong to the same race; yet on one island alone, namely Nunemaya, “ the men have splendid beards ; whilst on the other islands “ they •‘have, as a rule, a dozen straggling hairs for a beard.”17 Throughout the great American continent the men may be said to be beardless ; but in almost all the tribes a few short hairs are apt to appear on the face, espe- cially during old age. With the tribes of North America, Gatlin estimates that eighteen out of twenty men are completely destitute by nature of a beard ; but occa- sionally there may be seen a man, who has neglected to pluck out the hairs at puberty, with a soft beard an inch or two in length. The Guaranys of Paraguay differ from all the surrounding tribes in having a small beard, and even some hair on the body, but no whiskers.18 1 am informed by Mr. D. Forbes, who particularly attended to this subject, that the Aymaras and Quicliuas of the Ooi dill era are remarkably hairless, yet in old age a few straggling hairs occasionally appear on the chin. The men of these two tribes have very little hair on the \aiious parts of the body where hair grows abundantly
pure negroes and their crossed offspring seem to have bodies almost a* hairy as those at Kurojieans.
18 Wallace, ‘ The Malay Arch.’ vol. ii. 1S69, p. 178.
I)r. J. Barnard Davis on Oceanic Races, in ‘ Anthropolog. Review,’ April, 1870, p. 185, 191. 1 °
18 Catliu, ‘North American Indians,’ 3rd edit. 1842, vol. ii. n 227- On the Guaranys, see Azam, 1 Voyages dans l’Ame'rique Merid.’ tom. it 1809, p. 58 ; also Rengger, ‘ Saugethicre von Paraguay,’ s. 3.
Chap XIX.
LAW OF BATTLE,
323
m Europeans, and the women have none on the corre- sponding parts. The hair on the head, however, attains an extraordinary length in both sexes, often reaching almost to the ground ; and this is likewise the case with some of the N. American tribes. In the amount of hair, and in the general shape of the body, the sexes °f the American aborigines do not differ from each other so much as with most other races of mankind.19 This fact is analagous with what occurs with some allied monkeys ; thus the sexes of 1:1 te chimpanzee arc not as different as those of the gorilla or orang.20
In the previous chapters we have seen that with mammals, birds, fishes, insects, &c., many characters, "thick there is every reason to believe were primarily gained through sexual selection by one sex alone, have been transferred to both sexes. As this same form of transmission has apparently prevailed to a large extent With mankind, it will save much useless repetition if "e consider the characters peculiar to the male sex together with certain other characters common to both sexes.
Laiv of Battle. — With barbarous nations, for instance with the Australians, the women are the constant cause °f war both between the individuals of the same tribe a>id between distinct tribes. So no doubt it was in ancient times ; “ iiam fuit ante Helenam mulier teter- " lima belli causa.” With the North American Indians, the contest is reduced to a system. That excellent ob-
ls Prof, and Mra. Agassiz (‘ Journey in Brazil/ p. 530) remark ^&t tlie sexes of the American Indians (lifter less than those of the neoroes and of the higher races. See also Rengger, ibid. p. 3, on the ^•uaranys.
“° Riitimeyer, ‘Die Grenzen der Thierwelt; eine Betrachtung zu Erwin’s Lehre,’ 18GS, s. 54.
324
SEXUAL SELECTION: MAN.
Part II.
server, Hearn e,-1 says : — “ It has ever been the custom “ among these people for the men to wrestle for any “ woman t0 " llom they are attached ; and, of course, the “ strongest party always carries off the prize. A weak “ man unless he be a good hunter, and well-beloved, “is seldom permitted to keep a wife that a stronger “man thinks worth his notice. This custom prevails
t loughout all the tribes, and causes a great spirit “ of emulation among their youth, who are upon all ' occas,ons> from their childhood, trying their strength “ and skill in wrestling.” With the Guanas of South America, Azara states that the men rarely marry till twenty or more years old, as before that age "they cannot conquer their rivals.
Other similar facts could he given ; but even if we had no evidence on this head, we might feel almost sure, from the analogy of the higher Quadrumana,22 that the law of battle had prevailed with man during the early stages of his development. The occasional appearance at the present day of canine teeth which project above the others, with traces of a diastema or open space for the reception of the opposite canines, is m all probability a case of reversion to a former state, when the progenitors of man were provided with these weapons, like so many existing male Quadrumana, It was remarked in a former chapter that as man gra- dually became erect, and continually used his hands and arms for fighting with sticks and stones, as well as tor the other purposes of life, he would have used his
ln.A ,fT fTC0 01 Wales Fort'’ 8to- «lit. Dublin, 1796,
p m Sa J Lubbock (‘Origin of Civilisation,’ 1S70, p. 69) gives other and similar eases ia North America. For the Guanas of S. America see Azara, Voyages,’ &o. tom. ii. p. 94.
r 22 °? “ale Serillas, see Dr. .Savage, in ‘ Boston
Journal of Nat Hist, voh v. 1847, p. 423. On Preslytis cnteUns, see the 1 Indian Field,’ 1859, p. 146.
Ciur. XIX.
LAW OF BATTLE.
325
jaws and teeth less and less. The jaws, together with their muscles, would then have become reduced through disuse, as would the teeth through the not well under- stood principles of correlation and the economy of growth ; for ive everywhere see that parts which are no longer of service arc reduced in size. By such steps the original inequality between the jaws and teeth in the two sexes of mankind would ultimately have been quite obliterated. The case is almost parallel with that of many male Buminants, in which the canine teeth have been reduced to mere rudiments, or have disappeared, apparently in consequence of the develop- ment of horns. As the prodigious difference between the skulls of the two sexes in the Gorilla and Orang, stands in close relation with the development of the immense canine teeth in the males, we may infer that the reduction of the jaws and teeth in the early male progenitors of man led to a most striking and favourable change in his appearance.
There can be little doubt that the greater size and strength of man, in comparison with woman, together with his broader shoulders, more developed muscles, rugged outline of body, his greater courage and pug- nacity, are all due in chief part to inheritance from some early male progenitor, who, like the existing anthropoid apes, -was thus characterised. These cha- racters will, however, have been preserved or even augmented during the long ages whilst man was still in a barbarous condition, by the strongest and boldest men having succeeded best in tlie general struggle for life, as well as in securing wives, and thus having left a large number of offspring. It is not probable that the greater strength of man was primarily acquired through the inherited effects of his having worked harder than Woman for his own subsistence and that of his family ;
326-
SEXUAL SELECTION: MAN.
Pakt II-
for the women in all barbarous nations are compelled to work at least as hard as the men. With civilised people the arbitrament of battle for the possession of the women has long ceased ; on the other hand, the men, as a general rule, have to work harder than the women lor their mutual subsistence ; and thus their greater stieugth will have been kept up.
Difference in the Mental Powers of the two Sexes.— With respect to differences of this nature between man and woman, it is probable that sexual selection has played a very important part. I am aware that some writers doubt whether there is any inherent difference ; but this is at least probable from the analogy of the lower animals which present other secondary sexual characters. No one will dispute that the bull differs in disposition from the cow, the wild-boar from the sow, the stallion from the mare, and, as is well known to the keepers of menageries, the males of the larger apes from the females. Woman seems to differ from man in mental disposition, chiefly in tier greater tender- ness and less selfishness; and this holds good even wit i savages, as shewn by a well-known passage in ungo Park s Travels, and by statements made by many other travellers. Woman, owing to her maternal instincts, displays these qualities towards her infants in an eminent degree ; therefore it is likely that she shou d often extend them towards her fellow-creatures. Man is the rival of other men ; he delights in com- petition, and this leads to ambition which passes too easily into selfishness. These latter qualities seem to be his natural and unfortunate birthright. It is gene- rally admitted that with woman the powers of intuition, of rapid perception, and perhaps of imitation, are more strongly marked than in man; but some, at least, of
Ciiap. XIX.
MENTAL TOWERS OF MAN AND WOMAN. 32 1
these faculties are characteristic of the lower races, and therefore of a past and lower state of civilisation.
The chief distinction in the intellectual powers of the two sexes is shewn by man attaining to a higher eminence, in whatever lie takes up, than woman can attain — whether requiring deep thought, reason, or imagination, or merely the nse of the senses and hands. If two lists were made of the most eminent men and women in poetry, painting, sculpture, music, — comprising composition and performance, histoiy, science, and philosophy, with half-a-dozen names under each subject, the two lists would not bear comparison. We may also infer, from the law of the deviation of averages, so well illustrated by Mr. Galton, in his work on 1 Hereditary Genius,’ that it men are capable of decided eminence over women in many subjects, the average standard of mental power in man must be above that of woman.
The half-human male progenitors of man, and men in a savage state, have struggled together during many generations for the possession of the lemales. But mere bodily strength and size would do little for victory, unless associated with courage, perseveianc.e, and detei- mined energy. With social animals, the young males have to pass' through many a contest before they win a female, and the older males have to retain their females by renewed battles. They have, also, in the case of man, to defend their females, as well as their young, from enemies of all kinds, and to hunt for their joint subsistence. But to avoid enemies, or to attack them with success, to capture wild animals, and to invent and fashion weapons, requires the aid of the higher mental faculties, namely, observation, reason, inven- tion, or imagination. These various faculties will thus have been continually put to the test, and selected
328
SEXUAL selection: man.
Part II-
dining manhood ; they will, moreover, have been strengthened by use during this same period of life. Consequently, in accordance with the principle often alluded to, we might expect that they would at least tend to be transmitted chiefly to the male offspring at the corresponding period of manhood.
Now, when two men are put into competition, or a man with a woman, who possess every mental quality m the same perfection, with the exception that the one has higher energy, perseverance, and courage, tins one will generally become more eminent, what- ever the object may he, and will gain the victory.23 He may be said to possess genius— for genius has been declared by a great authority to he patience; and patience, in this sense, means unflinching, undaunted pci. severance. But this view of genius is perhaps
deficient: for without the higher powers of the imagi- nation and reason, no eminent success in many subjects c-au be gained. These latter as well as the former inanities will have been developed in man, partly through sexual selection,— that is, through the contest of rival males, and partly through natural selection,— that is, ro m success in the general struggle for life ; and as m both cases the struggle will have been during maturity, the characters thus gained will have been transmitted more fully to the male than to the female offspring. It accords with the view that some of our mental faculties have been modified or strengthened through sexual selection, that, firstly, they undergo, as is generally admitted, a considerable change at puberty, and, secondly, that eunuchs remain throughout life infe-
« St,uart Ml.1! “lrs Tlle Subjection of Women,’ 1SG9, p. 122), the m whloh “ost excels woman are those which require
‘ most plodding, and long hammering at single thoughts.” What is this but energy and perseverance ?
C'lIAP. XIX.
MENTAL TOWERS OF MAN AND WOMAN. 329
rior in these same qualities. Thus man has ultimately become superior to woman. It is, indeed, fortunate that the law of the equal transmission of characters to both sexes has commonly prevailed throughout the whole class of mammals ; otherwise it is probable that man would have become as superior in mental endowment to woman, as the peacock is in ornamental plumage to the peahen.
It must be borne in mind that the tendency in cha- racters acquired at a late period of life by either sex, to be transmitted to the same sex at the same age, and of characters acquired at an early age to be transmitted to both sexes, are rules which, though general, do not always hold good. If they always held good, we might conclude (but I am here wandering beyond my proper bounds) that the inherited effects of the early education of bovs and girls would be transmitted equally to both sexes ; so that the present inequality between the sexes in mental power could not be effaced by a similar course of early training ; nor can it have been caused by their dissimilar early training. In order that woman should reach the same standard as man, she ought, when nearly adult, to be trained to energy and perse- verance, and to have her reason and imagination exer- cised to the highest point ; and then she would pro- bably transmit these qualities chiefly to her adult daughters. The whole body of women, however, could not be thus raised, unless during many generations the women who excelled in the above robust virtues Were married, and produced offspring in larger numbers than other women. As before remarked with respect to bodily strength, although men do not now fight for the sake of obtaining wives, and this form of selection has passed away, yet they generally have to undergo, during manhood, a severe struggle in order to maintain themselves and their iamilies ; and this will tend to keep
330
SEXUAL SELECTION: MAN.
Fart II.
up or even increase their mental powers, and, as a con- sequence, the present inequality between the sexes.24
Voice and Musical Powers. — In some species of Quad- rumana there is a great difference between the adult sexes, in the power of the voice and in the development of the vocal organs ; and man appears to have inherited this difference from his early progenitors. His vocal cords are about one-third longer than in woman, or than in boys ; and emasculation produces the same effect on him as on the lower animals, for it “ arrests that pi'0' “ minent growth of the thyroid, &c., which accompanies “the elongation of the cords.”23 With respect to the cause of this difference between the sexes, 1 have nothing to add to the remarks made in the last chapter on the probable effects of the long-continued use of the vocal organs by the male under the excitement of love, rage, and jealousy. According to Sir Duncan Gibb,26 the voice differs in the different races of mankind ; ant with the natives of Tartary, China, &c., the voice of the male is said not to differ so much from that of the female, as in most other races.
The capacity and love for singing or music, though not a sexual character in man, must not here be passed over. Although the sounds emitted by animals of al kinds serve many purposes, a strong case can be made out, that the vocal organs were primarily used and per
24 An observation by Vogt bears on this subject : be says, it *s n “ remarkable circumstance, that the difference between the sexes, »s “ regards the cranial cavity, increases with the development of
“ race, so that the male European excels much more the female, tb»
“ the negro the negress. Welcker confirms this statement of Huschke “ from his measurements of negro and German skulls.” But V°S admits (* Lectures on Man,’ Eng. translat. 1864, p. 81) that more obse - vations are requisite on this point.
25 Owen, ‘ Anatomy of Vertebrates,’ vol. iii. p. 603.
28 ‘ Journal of the Anthropolog. Soc,’ April, 1S69, p. lvii. ami lxvn
Chap. XIX.
MUSICAL POWERS.
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fected in relation to the propagation of the species. Insects and some few spiders are the lowest animals which voluntarily produce any sound ; and this is gene- rally effected by the aid of beautifully constructed stridulating organs, which are often confined to the males alone. The sounds thus produced consist, I believe in all cases, of the same note, repeated rhythmically ; and this is sometimes pleasing even to the ears ot man. Their chief, and in some cases exclusive use appears to be either to call or to charm the opposite sex.
The sounds produced by fishes are said in some cases to be made only by the males during the breeding season. All the air-breathing Yertebrata necessarily possess an apparatus for inhaling and expelling air, with a pipe capable of being closed at one end. cnee w len the primeval members of this class were strong y ex- cited and then- muscles violently contracted, purpose- less sounds would almost certainly have been produced ; and these, if they proved in any way serviceable, might readily have been modified or intensified by the pre- servation of properly adapted variations. The Amphi- bians are the lowest Vertebrates which breathe air ; and many of these animals, namely, frogs and toads, possess vocal organs, which are incessantly used during the breeding-season, and which are often more highly developed in the male than in the female. The male alone of the tortoise utters a noise, and this only during the season of love. Male alligators roar or bellow during the same season. Every one knows how largely birds use their vocal organs as a means of courtship ; and some species likewise perform what may be called instrumental music.
In the class of Mammals, with which we are here
27 Dr. Scudder, “ Notes on Stridulation,” in ‘ Proc. Boston Soc. of Nat. Hist.’ vol. xi. April, 1868.
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move particularly concerned, the males of almost all the species use their voices during the breeding-season much more than at any other time ; and some are abso- lately mute excepting at this season. Both sexes of other species, or the females alone, use their voices as a love- call. Considering these facts, and that the vocal organs of some quadrupeds are much more largely developed in the male than in the female, either permanently or temporarily during the breeding season ; and consider- ing that in most of the lower classes the sounds produced by the males, serve not only to call but to excite or allure the female, it is a surprising fact that we have not as yet any good evidence that these organs are used by male mammals to charm the females. The American Sfycstss caraya perhaps forms an exception, as does more pro- bably one ot those apes which come nearer to man, namely, the Hylobates agilis. This gibbon has an extremely loud but musical voice. Mr. Waterhouse states," “It appeared to me that in ascending and ‘ descending the scale, the intervals were always exactly "half-tones; and I am sure that the highest note was the exact octave to the lowest. The quality of the ^ notes is very musical ; and 1 do not doubt that a good “ Uolinist would be able to give a correct idea of the gibbons composition, excepting as regards its loud- “ ness- ’ Mr. Waterhouse then gives the notes. Pi'0' lessor Owen, who is likewise a musician, confirms the foregoing statement, and remarks that this gibbon “alone of brute mammals may be said to sing.” U appears to be much excited after its performance. Un- fortunately its habits have never been closely observed in a state of nature ; but from the analogy of almost
28 Given in W. G. L. Martin’s ‘General Introduet. to Nat. Hist, of Mamm. Animals, 1841, p. 432; Owen, ‘Anatomy of Vertebrates,’ v0 * iii. p. 600.
Chap. XIX.
MUSICAL POWERS.
333
all other animals, it is highly probable that it utters its musical notes especially during the season of courtship.
The perception, if not the enjoyment, of musical cadences and of rhythm is probably common to all ani- mals, and no doubt depends on the common physio- logical nature of their nervous systems. kven Crus- taceans, which are not capable of producing any voluntary sound, possess certain auditory hairs, which have been seen to vibrate when the proper musical notes are struck.29 It is well known that some dogs howl when hearing particular tones. Seals apparently ap- preciate music, and their fondness for it “was well “ known to the ancients, and is often taken advantage of by the hunters at the present day”3 \Vith all those animals, namely insects, amphibians, and birds, the males of which during the season of courtship incessantly produce musical notes or mere rhythmical sounds, we must believe that the females are able to appreciate them, and arc thus excited or charmed; otherwise the incessant efforts of the males and the complex structures often possessed exclusively by them
would he useless. ....
With man song is generally admitted to be the basis
or origin of instrumental music. As neither the enjoy- ment nor the capacity of producing musical notes are faculties of the least direct use to man in reference to his ordinary habits of life, they must be ranked amongst the most mysterious with which he is endowed. They are present, though in a very rude and as it appears almost latent condition, in men of a, 11 races, even the most savage ; hut so different is the taste of the different races, that our music gives not the least pleasure to savages, and their music is to us hideous
23 Helmholtz, ‘ The'orie Pliys. de la Musique,’ 1S68, p. 187. 80 Mr. R. Brown, in ‘Proc. Zoo. Soc.’ 1868, p. 410.
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and unmeaning. Dr. Seemann, in some interesting remarks on this subject,31 “doubts whether even amongst „ t,le natl0Ils of Western Europe, intimately connected <{ as the-v are b>r cIose an-d frequent intercourse, the „ !rU1'S!C of ,the one is interpreted in tlie same sense „ .7 tlle. others. By travelling eastwards we find that there is certainly a different language of music. a ' onSs 01 joy and dance-accompaniments are no longer,
■ as with us, in tlie major keys, but always in the minor.” hether or not the half-human progenitors of man pos- sessed like the before-mentioned gibbon, the capacity of producing, and no doubt of appreciating, musical notes we have every reason to believe that man pos- sessed these faculties at a very remote period, for singing and music are extremely ancient arts, poetry, which may be considered as the offspring of soim is likewise so ancient that many persons have felt aston- ishment that it should have arisen during the earliest ages of which we have any record.
The musical faculties, which are not wholly deficient m any race, are capable of prompt and high develop- ment as we see with Hottentots and Negroes, who have readily become excellent musicians, although they do no practise in their native countries anything that we should esteem as music. But there is nothing ano- malous in this circumstance : some species of birds w ic 1 never naturally sing, can without much difficulty be taught to perform ; thus the house-sparrow has learnt t ie song of a linnet. As these two species are closely allied and belong to the order of Insessores, which includes nearly all the singing-birds in the world, it is quite possible or probable that a progenitor of the spar-
!1 ‘Journal of Ajjfcropolog. See.’ Oct. 1870, p civ See also the “!n-l °n’ ’ W Ch COntai“ a“ admirable account of the habits
Chap. XIX.
MUSICAL POWERS.
335
row may have been a songster. It is a much more remarkable fact that parrots, which belong to a group distinct from the Insessores, and have differently-con- structed vocal organs, can be taught not only to speak, but to pipe or whistle tunes invented by man, so that they must have some musical capacity. Nevertheless it would be extremely rash to assume that parrots are descended from some ancient progenitor which was a songster. Many analogous cases could be advanced of organs and instincts originally adapted for oue pur- pose, having been utilised for some quite distinct purpose.3'" Hence the capacity for high musical de- velopment, which the savage races of man possess, may be due either to our semi-human progenitors having Practised some rude form of music, or simply to their having acquired for some distinct purposes the proper vocal organs. But in this latter case we must assume that they already possessed, as in the above instance of the parrots, and* as seems to occur with many animals, some sense of melody.
Music affects every emotion, but does not by itself ex- cite in us the more terrible emotions of horror, rage, &c. It awakens the gentler feelings of tenderness and love, which readily pass into devotion. It likewise stirs up in Us the sensation of triumph and the glorious ardour for war. These powerful and mingled feelings may well give vise to the sense of sublimity. We can concentrate, as
52 Since ties chapter has been printed I have seen a valuable article ty Mr. Chauucey Wright (‘ North Amer. Review,’ Oct. 1870, page 293), Who, in discussing the above subject, remarks, “ There are many con- “ sequences of the ultimate laws or uniformities of nature through “ which the acquisition of one useful power will bring with it many “ resulting advantages as well as limiting disadvantages, actual or “ possible, which the principle of utility may not have comprehended l* in its action.” This principle has an important bearing, as I have attempted to shew in the second chapter of this work, on the acqni- sitiou by man of some of his mental characteristics.
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Dr. Seemann observes, greater intensity of feeling in a single musical note than in pages of writing. Nearly the same emotions, but much weaker and less complex, are probably felt by birds when the male pours forth Ids full volume of song, in rivalry with other males, for the sake of captivating the female. Love is still the commonest theme of our own songs. As Herbert Spencer remarks, music “arouses dormant sentiments of which we had not ‘ conceived the possibility, and do not know the meaning > or, as Richter says, tells us of t hings we have not seen “ ancl shall not see.” 33 Conversely, when vivid emotions are felt and expressed by the orator or even in common speech, musical cadences and rhythm are instinctively used. Monkeys also express strong feel inns in different tones anger and impatience by low, — fear and pain by high notes.34 The sensations and ideas excited in us by music, or by the cadences of impassioned oratory, appear from their vagueness, yet depth, like mental re- versions to the emotions and thoughts of a long-past age.
All these facts with respect to music become to a certain extent intelligible if we may assume that musical tones and rhythm were used by the half'
Sec the very interesting discussion on the Origin and Function of TU aMr‘ Herb0rt 8P°“oer> hi his collected ‘ Essays,’ 1858, P- , / . , ; Spencer comes to an exactly opposite conclusion to that at wlncU I have arrived. He concludes that the cadences used in emo- tional speech afford the foundation from which music has been developed; whilst I conclude that musical notes and rhythm were first acquired by the male or female progenitors of mankind for the sake of charming the opposite sex. Thus musical tones became firmly associated with some of the strongest passions an animal is capable of feeling, mid arc consequently used instinctively, or through association, when strong emotions are expressed in speech. Mr. Spencer does not offer any satisfactory explanation, nor can I, why high or deep notes should bo expressive, both with man and the lower animals, of certain emotions. Mr. Spencer gives also an interesting discussion on the relations between poetry, recitative, and song.
34 Eengger, 1 Saugethiere von Paraguay s, 49.
Chap. XIX.
MUSICAL POWERS.
337
human progenitors of man, during the season of court- ship, when animals of all kinds are excited by the strongest passions. In this case, from the deeply-laid principle of inherited associations, musical tones would be likely to excite in us, in a vague and indefinite man- ner, the strong emotions of a long-past age. Bearing in mind that the males of some quadrumanous animals have their vocal organs much more developed than in the females, and that one anthropomorphous species pours forth a whole octave of musical notes and may be said to sing, the suspicion does not appear improbable that the progenitors of man, either the males or females, or both sexes, before they had acquired the power of expressing their mutual love in articulate language, endeavoured to charm each other with musical notes and rhythm. So little is known about the use of the voice by the Quadrmnana during the season ot love, that We have ha rdly any means of judging whether the habit of singing was first acquired by the male or female progenitors of mankind. Women are generally thought to possess sweeter voices than men, and as far as this serves as any guide we may infer that they first acquired musical powers in order to attract the other sex.35 But if so, this must have occurred long ago, before the pro- genitors of man had become sufficiently human to treat and value their women merely as useful slaves. The impassioned orator, bard, or musician, when with his Varied tones and cadences he excites the strongest emotions in his hearers, little suspects that he uses the same means by which, at an extremely remote period, bis half-human ancestors aroused each other’s ardent passions, during their mutual courtship and rivalry.
55 See an interesting discussion on tliis subject by H'ackel, 1 Generelle Slorph.’ B. ii. 18C6, s. 246.
VOL. II.
Z
338
sexual selection: man.
Part II.
On the influence of beauty in determining the mar- riages of mankind. — In civilised life man is largely, but by no means exclusively, influenced in the choice of his wife by external appearance ; but we are chiefly concerned with primeval times, and our only means of forming a judgment on this subject is to study the habits of existing semi-civilised and savage nations. If it can be shewn that the men of different races prefer women having certain characteristics, or conversely that the women prefer certain men, we have then to enquire whether such choice, continued during many generations, would produce any sensible effect on the race, either on one sex or both sexes ; this latter circumstance depending on the form of inheritance which prevails.
It will be well first to shew in some detail that savages pay the greatest attention to their personal appearance.36 That they have a passion for ornament is notorious; and an English philosopher goes so lar as to maintain that clothes were first made for ornament and not for warmth. As Professor Waitz remarks, “ however poor “ and miserable man is, he finds a pleasure in adorning “ himself.” The extravagance of the naked Indians of South America in decorating themselves is shewn “by “ a man of large stature gaining with difficulty enough “ by the labour of a fortnight to procure in exchange
36 A full and excellent account of the manner in -which savages in all parts of the world ornament themselves is given by the Italian traveller, Prof. Mantcgazza, ‘Rio de la Plata, Viaggi e Studi,’ 1867, p. 525-545; all the following statements, when other references are not given, are taken from this work. See, also, Waitz, ‘ Introduce to Anthropolog.’ Eng. trnnsl. vol. i. 1863, p. 275, et passim. Lawrence also gives very full details in his ‘Lectures on Physiology,’ 1822. Since this chapter was written Sir J. Lubbock has published bis ‘ Origin of Civilisation,’ 1870, in which there is an interesting chapter on the present subject, and from which (p. 42, 48) I have taken some facts about savages dyeing their teeth and hair, and piercing their teeth.
Chap. XIX.
LOVE OF ORNAMENTS.
339
“the cliica necessary to paint himself red.”37 The ancient barbarians of Europe during the Reindeer period brought to their caves any brilliant or singular objects which they happened to find. Savages at the present day everywhere deck themselves with plumes, neck- laces, armlets, earrings, &c. They paint themselves in the most diversified manner. “ If painted nations,” as Humboldt observes, “ had been examined with the same “ attention as clothed nations, it would have been per- “ ceived that the most fertile imagination and the most “ mutable caprice have created the fashions of painting,
“ as well as those of garments.”
In one part of Africa the eyelids are coloured black ; in another the nails are coloured yellow or purple. In many places the hair is dyed of various tints. In dif- ferent countries the teeth are stained black, red, blue, &c., and in the Malay Archipelago it is thought shame- ful to have white teeth like those of a dog. Not one great country can be named, from the Polar regions in the north to New Zealand in the south, in which the aborigines do not tattoo themselves. This practice was followed by the Jews of old and by the ancient Britons. InAfriea some of the natives tattoo themselves, but it is much more common to raise protuberances by rubbing salt into incisions made in various parts of the body ; and these are considered by the inhabitants of Kordofan and Darfur “ to be great personal attractions.” In the Arab countries no beauty can be perfect until the cheeks “or temples have been gashed.”38 In South America, ns Humboldt remarks, “a mother would be accused of
37 Humboldt, ‘Personal Narrative,’ Eng. translat. vol. iv. p.
on the imagination shewn in painting the body, p. 022 ; on modifying the form of the calf of the leg. p. 466.
38 1 The Nile Tributaries,’ 1867 ; 1 The Albert N’yanzn,’ 1866, vol. l. p. 218.
Z 2
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SEXUAL selection: max.
Pari II.
“ culpable indifference towards her children, if she did “not employ artificial means to shape the calf of the leg “ after the fashion of the country.” In the Old and New
oild the shape of the skull was formerly modified during infancy in the most extraordinary manner, as is still the case in many places, and such deformities are considered ornamental. For instance, the savages of Colombia 39 deem a much flattened head “ an essential “ point of beauty.”
Ihe hair is treated with especial care in various countries ; it is allowed to grow to full length, so as to reach to the ground, or is combed into “a compact “frizzled mop, which is the Papuan’s pride and glory.”40 In Forth ern Africa “a man requires a period of from “ eight to ten years to perfect his coiffure.” With other nations the head is shaved, and in parts of South Ame- rica and Africa even the eyebrows are eradicated. The natives of the Upper Nile knock out the four front teeth, saying that they do not wish to resemble brutes. Further south, the Batokas knock out the two upper incisors, which, as Livingstone41 remarks, gives the face a hideous appearance,, owing to the growth of the lower jaw ; but these people think the presence of the incisors most unsightly, and on beholding some Europeans, cried out, « Look at the great teeth ! ” The great chief Sebi- tuani tried in vain to alter this fashion. In various parts oi A Inca and in the Malay Archipelago the natives file t ic incisor teeth into points like those of a saw, or pierce them with. holes, into which they insert studs.
" Qno*e* b-v Priohar'b ‘Hive. Hist, of Mankind,’ 4th edit. vol. i. 1851, p. 321.
" °;i thf ^puans, Wallace, ‘The Malay Archipelago,’ vol. ii. p. 415. On the coiffure of the Africans, Sir S. Baker, ‘The Albert jn yanza,’ vol. l. p. 210.
41 ‘ Travels, p. 533.
Chap. XIX.
LOVE OF ORNAMENTS.
341
As the face with ns is chiefly admired for its beauty, so with savages it is the chief seat of mutilation. In all quarters of the world the septum, and more rarely the wings of the nose are pierced, with rings, sticks, feathers, and other ornaments inserted into the holes. The ears are everywhere pierced and similarly orna- mented, and with the Botucudos and Lengnas of South America the hole is gradually so much enlarged that the lower edge touches the shoulder. In North and South America and in Africa either the upper or lower lip is pierced ; and with the Botocudos the hole in the lower lip is so large that a disc of wood four inches in diameter is placed in it. Mantegazza gives a curious account of the shame felt by a South American native, and of the ridicule which he excited, when he sold his tenibeta, — the large coloured piece of wood which is passed through the hole. In central Africa the women perforate the lower lip and wear a crystal, which, from the movement of the tongue, has “ a wriggling motion “indescribably ludicrous during conversation.” The wife of the chief of Latooka told Sir S. Baker '1J that his “ wife would be much improved if she would extract “ her four front teeth from the lower jaw, and wear the “ long pointed polished crystal in her under lip.” Fur- ther south with the Makalolo, the upper lip is perforated, and a large metal and bamboo ring, called a felele, is worn in the hole. “ This caused the lip in one case to “project two inches beyond the tip of the nose; and “ when the lady smiled the contraction of the muscles “ elevated it over the eyes. ‘ Why do the women wear “‘these things?’ the venerable chief, Chinsurdi, was “ asked. Evidently surprised at such a stupid question, “ he replied, ‘ For beauty ! They are the only beautiful
42 ‘ The Albert N’yanza,’ I860, vol. i. p. 2X7.
342
sexual selection: man.
Part II.
‘“things women Lave; men have beards, women have “ ‘ none. What kind of a person would she be without “ ‘ the peloid ? She would not be a woman at all with a “ * mouth like a man, but no beard.’ ”43 Hardly any part of the body, which can be unna- turally modified, has escaped. The amount of suffering thus caused must have been wonderfully great, for many of the operations require several years for their completion, so that the idea of their necessity must be imperative. The motives are various; the men paint their bodies to make themselves appear terrible in bat- tle; certain mutilations are connected with religious rites; or they mark the age of puberty, or the rank of the man, or they serve to distinguish the tribes. As with savages the same fashions prevail for long periods,44 mutilations, from whatever cause first made, soon come to be valued as distinctive marks. But self-adornment, vanity, and the admiration of others, seem to be the commonest motives. In regard to tattooing, I was told by the missionaries in New Zealand, that when they tried to persuade some girls to give up the practice, they answered, “ We must just have a few “ idles on our lips ; else when we grow old we shall be “ so very ugly.” With the men of New Zealand, a most capable judge45 says, “to have fine tattooed faces was “ fde great ambition of the young, both to render them- “ selves attractive to the ladies, and conspicuous in war.” A star tattooed on the forehead and a spot on the chin
43 Livingstone, British Association,’ I860; report given in the * Athenaeum,’ July 7, 1860, p. 29.
44 Sir S. Baker (ibid. vol. i. p. 210) speaking of the natives of Central Africa says, “every tribe has a distinct and unchanging fashion for “ dressing the hair.” Sec Agassiz (‘ .Tourney in Brazil,’ 1868, p. 318) on the invariability of the tattooing of the Amazonian Indians.
45 Kev. E. Taylor, < New Zealand and its Inhabitants,’ 1855, p. 152.
Chap. XIX.
BEAUTY.
343
are thought by the women in one part of Africa to be irresistible attractions.46 In most, but not all parts oi the world, the men are more highly ornamented than the women, and often in a different manner ; sometimes, though rarely, the women are hardly at all ornamented. As the women are made by savages to perform the greatest share of the work, and as they are not allowed to eat the best kinds of food, so it accords with the cha- racteristic selfishness of man that they should not be allowed to obtain, or to use, the finest ornaments. Lastly it is a remarkable fact, as proved by the ore- going quotations, that the same fashions in modifying the shape of the head, in ornamenting the hair, in painting, tattooing, perforating the nose, lips, or ears, in removing or filing the teeth, &e., now prevail and have long prevailed in the most distant quarters qf the world. It is extremely improbable that these prac- tices which are followed by so many distinct nations are due to tradition from any common source. They rather indicate the close similarity of the mind of man, to what- ever race he may belong, in the same manner as the almost universal habits of dancing, masquerading, and making rude pictures.
Having made these preliminary remarks on the admiration felt by savages for various ornaments, and for deformities most unsightly in our eyes, let us see how' far the men are attracted by the appearance of their women, and what are their ideas of beauty. As I have heard it maintained that savages are quite indifferent about the beauty of their women, valuing them solely as slaves, it may be well to observe that this conclusion does not at all agree with the care which the women take in ornamenting themselves, or with
Mantcg:<zza, ‘ Yiaggi e Stuili,’ p. 542.
341
SEXUAL SELECTION: MAN.
Part II.
tieir vanity. Burcliell47 gives an amusing account of a Bush-woman, who used so much grease, red ochre, and shining powder, “ as would have ruined any but a very rich husband.” She displayed also “much" vanity and too evident a consciousness of her superiority.” Mr. Winwood Keade informs me that the negroes of the West Coast often discuss the beauty of their women, borne competent observers have attributed the fearfully common practice of infanticide partly to the desire felt by the women to retain their good looks.48 In several regions the women wear charms and love-philters to gam the affections of the men; and Mr. Brown enume- rates four plants used for this purpose by the women of .North-Western America.49
Hearne,50 who lived many years with the American Indians, and who was an excellent observer, says, in speaking of the women, “Ask a Northern Indian what is beauty, and he will answer, a broad flat face, small ■ •eyes, high cheek-bones, three or four broad black lines
aCr°SS eac]l cheek> a Io'v forehead, a large broad chin, a clumsy hook nose, a tawny hide, and breasts hanging- down to the belt.” Pallas, who visited the northern parts 0f the Chinese empire, says “those women are „ P, Tf! who have Mandschii form ; that is to say, a broad face, high cheek-bones, very broad noses, and enormous ears 51 and Vogt remarks that the obliquity of the eye, which is proper to the Chinese and Japanese,
^ ‘Tm7el* “ Africa,’ 1824, vol. i. p. 414.
186S S nVfrlail1il,er CkS Aussterben der Naturvolker,’
« n u ’ /if80 Azam> ‘ Voyages,’ Ac. tom. ii. p. IK;.
On the vegetable productions used by the North-Western Ameri- can Indians, 1 Pharmaceutical Journal ’ vol x
" ‘ A ;r“UT°A * Wales Fort,’' Svo. edit. 1796, p. 89.
^ P™hrard’ ‘toys. Hist, of Mankind,’ 3rd edit vol. iv. 184:4, p. 519; Vogt, ‘Lectures on Man,’ Eng. translat p 129 On the
185“0p 107 0hmeSe °“ thB Cingillese’ E‘ Tennent, ‘ Ceylon,’ vol. ii.
chap. XIX.
BEAUTY.
345
is exaggerated in their pictures for the purpose, as it “ it seems, of exhibiting its beauty, as contrasted with “the eye of the red-haired barbarians.” It is well hnown, as Hue repeatedly remarks, that the Chinese of tlie interior think Europeans hideous with their white skins and prominent noses. The nose is far from being too prominent, according to our ideas, in the natives of Ceylon ; yet “the Cliine.se in the seventh century, ac- “ customed to the flat features of the Mogul races, were “ surprised at the prominent noses of the Cingalese ; and “ Thsang described them as having ‘ the beak of a bird, “ with the body of a man/ ”
Finlayson, after minutely describing the people of Cochin China, says that their rounded heads and faces ftre their chief characteristics ; and- he adds, “ the “ roundness of the whole countenance is more striking “ in the women, who are reckoned beautiful in propor- “ tion as they display this form of face.” The Siamese have small noses with divergent nostrils, a wide mouth, rather thick lips, a remarkably large face, with very high and broad cheek-bones. It. is, therefore, not won- derful that “ beauty, according to our notion is a stranger !‘ to them. Yet they consider their own females to be “ much more beautiful than those of Europe.” 5a It is well known that with many Hottentot women Hie posterior part of the body projects in a wonderful fanner ; they are steatopygous ; and Sir Andrew Smith C certain that this peculiarity is greatly admired by the men.63 He once saw a woman who was considered a
32 Prichard, aa taken from Crawfurd and Finlayson, 1 Fhys. Hist, of Mankind,’ vol. iv. p. 534, 535.
33 Idem illustrissimns viator dixit miiii prmcinctorium vel tabulam f'Snunje, quod nobis teterfimum est, quondam permagno sestimari ab “oininibus in hac gente. Nunc res mutata est, et censcnt talem con- formation em minima optandam esse.
340
SEXUAL SELECTION: MAN.
Part II.
beauty, and she was so immensely developed behind, that when seated on level ground she could not rise, and had to push herself along until she came to a slope. Some of the women in various negro tribes are similarly charac- terised; and, according to Burton, the Sornal men “ are “ said to choose their wives by ranging them in a line, “ and by picking her out who projects farthest a ter go, “Nothing can be more hateful to a negro than the “ opposite form.” 64
With respect to colour, the negroes rallied Mungo Park on the whiteness of his skin and the prominence of his nose, both of which they considered as “ unsightly “ and unnatural conformations.” He in return praised the glossy jet of their skins and the lovely depression of their noses; this they said was “ honey-mouth,” never- theless they gave him food. The African Moors, also, “ knitted their brows and seemed to shudder ” at the whiteness ot his skin. On the eastern coast, the negro boys when they saw Eurton, cried out “Look at the “ white man ; does he not look like a white ape ?” On the western coast, as Mr. Winwood lleade informs me, the negroes admire a very black skin more than one of a lighter tint. But their horror of whiteness may be partly attributed, according to this same traveller, to the belief held by most negroes that demons and spirits are white.
The Banyai of the more southern part of the continent are negroes, but “ a great many of them are of a light “ coflee-and-milk colour, and, indeed, this colour is con- “ sidered handsome throughout the whole country ; ” so that here we have a different standard of taste. With the
54 ‘The Anthropological Review,’ November, 1864, p. 237. F°r additional references, see Waitz, ‘Introduct. to Anthropology,’ Eng* translat. 1863, vol. i. p. 1 05.
CHAP. XIX.
BEAUTY.
347
Kafirs, who differ much from negroes, “ the skin, except “ among the tribes near Delagoa Bay, is not usually “ black, the prevailing colour being a mixture of black “ and red, the most common shade being chocolate.
Dark complexions, as being most common are natu- “ rally held in the highest esteem. To be told that he “ is lighhcoloured, or like a white man, would be deemed “a very poor compliment by a Kafir. I have heard of one unfortunate man who was so very fair that no “ girl would marry him.” One of the titles of the Zulu king is “You who are black.”65 Mr. Galton, in speaking to me about the natives of S. Africa, remarked that their ideas of beauty seem very different from °urs ; for in one tribe two slim, slight, and pretty girls "'ere not admired by the natives.
Turning to other quarters of the world ; in J ava, a yellow, not a white girl, is considered, according to ■Kadame Pfeiffer, a beauty. A man of Cochin-China t! spoke with contempt of the wife of the English “ Ambassador, that she had white teeth like a dog, “ and a rosy colour like that of potato-flowers.” We bave seen that the Chinese dislike our white skin, and that the N. Americans admire “a tawny hide.” In K America, the Yura-caras, who inhabit the wooded, damp slopes of the eastern Cordillera, are remarkably pale-coloured, as their name in their own language °xpresses ; nevertheless they consider European women as very inferior to their own.56
** ‘ Mungo Park’s Travels in Africa," 4to. 1816, p. 53, 131. Burton’s statement is quoted by Schaaffhausen, ‘ Arcliiv fiir Antliropolog.’ 1866, s- 163. On tire Banyai, Livingstone, ‘ Travels,’ p. 64. On the Kafirs, the Rev. J. Shooter, 1 The Kafirs of Natal and the Zulu Country,’ 1857 P. 1.
50 For the Javanese and Coclrin-Chinese,’ see "Waltz, ‘ Introduct. to •‘Anthropology,' Kng. trauslat. vol. i. p. 305. On the Yura-caras, A.
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In several of the tribes of North America the hair on the head grows to a wonderful length ; and Catlin gives a curious proof how much this is esteemed, for the chief of the Crows was elected to this office from having the longest hair of any man in the tribe, namely ten feet and seven inches. Tire Aymaras and Quichuas of S. America, likewise have very long hair ; and this, as Mr. 1). Forbes informs me, is so much valued for the sake of beauty, that cutting it off was the severest punishment which he could inflict on them. In both halves of the continent the natives sometimes increase the apparent length of their hair by weaving into it fibrous substances. Although the hair on the head is thus cherished, that on the face is considered by the North American Indians “as very vulgar,” and every hair is carefully eradicated. This practice pre- vails throughout the American continent from Van- couver’s Island in the north to Tierra del Fuego in the south. When \ ork Minster, a Fucgian on board the
Beagle was taken back to his country, the natives told him he ought to pull out the few short hairs on his face. They also threatened a young missionary, who was left for a time with them, to strip him naked, and pluck the hairs from his face and body, yet he was far from a hairy man. This fashion is carried to such an ex- treme that the Indians of Paraguay eradicate their eye- brows and eyelashes, saying that they do not wish" to be like horses.57
It is remarkable that throughout the world the races
d’Orligny, as quoted in Prichard, ‘ Phys. Hist, of Mankind ’ yol v 3rd edit. p. 476.
" <North American Indians,’ by G. Catlin, 3rd edit. 1842, yol. i. P- 40; vol. ii. p. 22,. On the natives of Vancouver Island, see Sproat, •Scenes and Studies of Savage Life,’ 1868, p. 25. On the Indians of Paraguay, Azaia, ‘ Voyages,’ tom. ii. p. 105.
C>UP. XIX.
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which are almost completely destitute of a beard dislike hairs on the face and body, and take pains to eradicate them. The Kalmucks are beardless, and they are well known, like the Americans, to pluck out all straggling hairs; and so it is with the Polynesians, some of the ■Malays, and the Siamese. Mr. Yeitcli states that the Japanese ladies “all objected to our whiskers, consider- ‘ »ig them very ugly, and told us to cut them off, and ' be like Japanese men.” The New Zealanders are beardless; they carefully pluck out the hairs on the hice, and have a saying that “ There is no woman lor a “ hairy man.” 53
On the other hand, bearded races admire and greatly value their beards ; among the Anglo-Saxons every part °f the body, according to their laws, had a recognised ^alue ; “the loss of the beard being estimated at twenty 'shillings, while the breaking of a thigh was fixed at "'only twelve.”53 In the East men swear solemnly bv their beards. We have seen that Chinsurdi, the chief 01 the Makalolo in Africa, evidently thought that beards were a great ornament. With the Fijians in the Pacific the beard is “profuse and bushy, and is his 'greatest pride;” whilst the inhabitants of the adja- Ceut archipelagoes of Tonga and Samoa are “ beardless,
’ and abhor a rough chin.” In one island alone of the kJlice group “the men are heavily bearded, and not a ** httle proud thereof.”60
18 On the Siamese, Prichard, ibid. vol. iv. p. 533. On the Japanese, <-'tch in ‘Gardeners’ Chronicle,’ 18(10, p. 1104. On the New Zealanders lantegazza, ‘ Via.ggi e Studi,’ 1867, p. 526. For the other nations Mentioned, see references in Lawrence, ‘Lectures on Physiology, ’ &c. 1822, p.272.
11 Lubbock, ‘ Origin of Civilisation.’ 1S70, p. 321.
. 0 hr. Barnard Davis quotes Mr. Pritchard and others for these facts ltl regard to the Polynesians, in ‘ Anthropological Iteview,’ April, 1870, P- 185, 191.
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We thus see how widely the different races of man differ in their taste for the beautiful. In every nation sufficiently advanced to have made effigies of their gods or of their deified rulers, the sculptors no doubt have endeavoured to express their highest ideal of beauty and grandeur.61 Under this point of view it is well to compare in our mind the Jupiter or Apollo of the Greeks with the Egyptian or Assyrian statues ; and these with the hideous bas-reliefs on the mined buildings of Cen- tral America.
I have- met with very few statements opposed to the above conclusion. Mr. Winwood Eeade, however, who has had ample opportunities for observation, not only with the negroes of the West Coast of Africa, but with those of the interior who have never associated with Europeans, is convinced that their ideas of beauty are on the whole the same as ours. He has repeatedly found that lie agreed with negroes in their estimation ot the beauty of the native girls; and that their appreci- ation of the beauty of European women corresponded with ours. They admire long hair, and use artificial means to make it appear abundant ; they admire also a beard, though themselves very scantily pr O' vided. Mr. Eeade feels doubtful what kind of nose is most appreciated: a girl has been heard to say, “I “ do not want to marry him, he has got no nose ; ” and this shews that a very flat nose is not an object of admi- ration. We should, however, bear in mind that tke depressed and very broad noses and projecting jaws of the negroes of the West Coast are exceptional typeS with the inhabitants of Africa. Notwithstanding the foregoing statements, Mr. Eeade does not think it pi°'
61 Ch. Comte lias remarks to this effect in his ‘ Traite de legist' tion,’ 3rd edit. 1837, p. 136.
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liable that negroes would ever prefer the “ most beau- “ tiful European woman, on the mere grounds of physical admiration, to a good-loohing uegress.”1’2
The truth of the principle, long ago insisted on by Humboldt,63 that man admires and often tries to exag- gerate whatever characters nature may have given him, is shewn in many ways. The practice of beardless races extirpating every trace of a beard, and generally all the hairs on the body, offers one illustration. The skull has been greatly modified during ancient and modern times by many nations ; and there can bo little doubt that this has been practised, especially in N. and S. America, in order to exaggerate some natural and admired pecu- harity. Many American Indians are known to admire a bead flattened to such an extreme degree as to appear to us like that of an idiot. The natives on the north- western coast compress the head into a pointed cone ; and it is their constant practice to gather the hair into a knot on the top of the head, for the sake, as Hr. Wilson remarks, “ of increasing the apparent eleva- “ tion of the favourite conoid form.” The inhabitants °f Arakhan “ admire a broad, smooth forehead, and in “ order to produce it, they fasten a plate of lead on the “ heads of the new-born children.” On the other hand,
62 The Fucgians, as I have been informed by a missionary who long resided with them, consider European women as extremely beautiful ; but from what we have seen of the judgment of the other aborigines of America, I cannot but think that this must he a mistake, unless indeed the statement refers to the few Fuegians who have lived for some time With Europeans, and who must consider us as superior beings. 1 should add that a most experienced observer, Capt. Burton, believes that a Woman whom we consider beautiful is admired throughout (he world, ‘ Anthropological Keview,’ March, 1864, p. 245.
63 ‘Personal Narrative,’ Eng. translat. vol. iv. p. 518, and elsewhere. Mantegazza, in his ‘Yiaggi e Studi,’ 1867, strongly insists on this same principle.
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“ a broad, well-rounded occiput is considered a great “ beauty ” by the natives of the Fiji islands.64
As with the skull, so with the nose ; the ancient ITuds during the age of Attila were accustomed to flatten the noses of their infants with bandages, “ for the sake “ of exaggerating a natural conformation.” With the Tahitians, to be called long-nose is considered as an insult, and they compress the noses and foreheads of their children for the sake of beauty. So it is with the Malays of Sumatra, tire Hottentots, certain Xegroes, and the natives of Brazil.65 The Chinese have by nature unusually small feet ; 66 and it is well known that the women of the upper classes distort their feet to make them still smaller. Lastly, Humboldt thinks that the American Indians prefer colouring their bodies with red paint in order to exaggerate their natural tint ; and until recently European women added to their natu- rally bright colours by rouge and white cosmetics ; but I doubt whether many barbarous nations have had any such intention in painting themselves.
In the fashions of our own dress we see exactly the same principle and the same desire to carry every point to an extreme ; we exhibit, also, the same spirit of emulation. But the fashions of savages are far more permanent than ours; and whenever their bodies are
64 On the Skulls of the American tribes, see Nott and Gliddon, ' Types of Mankind,’ 1851, p. 4-10 ; Prichard, • Pliys. Hist, of Mankind,’ vol. i. 3rd edit. p. 3X1 ; on the natives of Arakhnn, ibid. vol. iv. p. 537- Wilson, ‘Physical Ethnology,’ Smithsonian Institution. 1863, p. 2SS ; on the Fijians, p. 290. Sir ,T. Lubbock (‘ Prehistoric Times,’ 2nd edit. 1869, p. 500) gives an excellent resume on this subject.
65 On the Huns, Godron, ‘He l’Esp&co,’ tom. ii. 1859, p. 300. On the Tahitians, "Waits, ‘ Antliropolog.’ Eng, trail-let. vol. i. p. 305. Marsden, quoted by Prichard, ‘Pliys. Hist, of Mankind,’ 3rd edit, vol. v. p. 67. Lawrence, ‘ Lectures on Physiology,’ p. 337.
66 This fact was ascertained in the ‘ Eeise der Novara : Anthropolog- Theil,’ Dr. Weisbach, 1867, s. 265,
Chap. XIX.
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artificially modified this is necessarily the case. The Arab women of the Upper Nile occupy about three days in dressing their hair ; they never imitate other tribes, “ but simply vie with each other in the superlativeness “ of their own style.” Dr. Wilson, in speaking of the compressed skulls of various American races, adds, “ such “ usages are among the least e radical >le, and long sur- “ vive the shock of revolutions that change dynasties “and efface more important national peculiarities.”6’ The same principle comes largely into play in the art of selection ; and we can thus understand, as I have else- where explained,63 the wonderful development of all the races of animals and plants which are kept merely for ornament. Fanciers always wish each character to be somewhat increased ; they do not admire a medium standard ; they certainly do not desire any great and abrupt change in the character of their breeds ; they admire solely what they are accustomed to behold, but they ardently desire to see each characteristic feature a little more developed.
No doubt the perceptive powers of man and the lower animals are so constituted that brilliant colours and certain forms, as well as harmonious and rhythmical sounds, give pleasure and are called beautiful ; but why this should be so, we know no more than why certain bodily sensations are agreeable and others disagreeable. It is certainly not true that there is in the mind of tnau any universal standard of beauty with respect to the human body. It is, however, possible that certain tastes may in the course of time become inherited, though I know of no evidence in favour of this belief ;
'7 * Smithsonian Institution, 1S63, p. 289. On the fashions of Arab Women, Sir S. Baker, ‘The Nile Tributaries,’ 1S67, p. 121.
68 ‘ The Variation of Animals and Tlants under Domestication,’ vol. i. P- 214 ; vol. ii. p. 240.
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35i SEXUAL SELECTION : MAN. Part II.
and if so, each race would possess its own innate ideal standard of beauty. It has been argued69 that ugli- ness consists in an approach to the structure of the lower animals, and tins no doubt is true with the more civilised nations, in which intellect is highly appre- ciated ; but a nose twice as prominent, or eyes twice as large as usual, would not be an approach in struc- ture to any of the lower animals, and yet would be utterly hideous. The men of each race prefer what they are accustomed to behold ; they cannot endure any great change ; but they like variety, and admire each characteristic point carried to a moderate ex- treme.70 Men accustomed to a nearly oval face, to straight and regular features, and to bright colours, admire, as we Europeans know, these points when strongly developed. On the other hand, men accus- tomed to a broad face, with high cheek-bones, a de- pressed nose, and a black skin, admire these points strongly developed. No doubt characters of all kinds may easily bo too much developed for beauty. Hence a perfect beauty, which implies many characters modified in a particular manner, will in every race be a prodigy- As the great anatomist Bichat long ago said, if every one were cast in the same mould, there would be no such thing as beauty. If all our women were to become as beautiful as the Venus de Medici, we should for a time be charmed ; but we should soon wish for variety ; and as soon as we hud obtained variety, we should wish to see certain characters in our women a little exaggerated beyond the then existing common standard.
68 Schanffhausen, ‘ Archivfiir Anthropologie,’ I860, s. 164.
70 Mr. Bain has collected (‘Mental ami Moral Science,’ J868, p. 304- 314) about a dozen more or less different theories of the idea of beauty ! but none are quite the same with that here given.
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CHAPTER XX.
Secondary Sexual Characters of Man — continued.
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 civilised and savage nations — Conditions favourable to sexual selection during primeval times — On the manner of action of sexual selection with mankind — On the women in savage tribes having some power to choose their husbands — Absence of hair on the body, and development of the beard — Colour of tire skin Summary.
We have seen in the last chapter that with all barbarous races ornaments, dress, and external appearance are highly valued; and that the men judge of the beauty of their women by widely different standards. We must next inquire whether this preference and the consequent selection during many generations of those "'omen, which appear to the men ol each race the most attractive, has altered the character either of the females alone or of both sexes. \\ ith mammals the general rule appears to be that characters of all kinds are inherited equally by the males and females ; we might therefore expect that with mankind any dia- meters gained through sexual selection by the females would commonly be transferred to the offspring of both sexes. If any change has thus been effected it is almost certain that the different races will have been differ- ently modified, as each has its own standard of beauty.
With mankind, especially with savages, many causes interfere with the action of sexual selection as far as the bodily frame is concerned. Civilised men are largely
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3'JG SEXUAL SELECTION : MAX. Part II-
attracted bv the mental channs of women, by their wealth, and especially by their social position ; for men rarely marry into a much lower rank of life. The men who succeed in obtaining the more beautiful women, will not have a better chance of leaving a long line of descendants than other men with plainer wives, with the exception of the few who bequeath their fortunes according to primogeniture. With respect to the op- posite form of selection, namely of the more attractive men by the women, although in civilised nations women have free or almost free choice, which is not the case with barbarous races, yet their choice is largely in- fluenced by the social position and wealth of the men ; and the success of the latter in life largely depends on their intellectual powers and energy, or on the fruits of these same powers in their forefathers.
There is, however, reason to believe that sexual selection has effected something in certain civilised and semi-civilised nations. Many persons are convinced, as it appears to me with justice, that the members of our aristocracy, including under this term all wealthy fami- lies in which primogeniture has long prevailed, from having chosen during many generations from all classes the more beautiful women as their wives, have become handsomer, according to the European standard of beauty, than the middle classes ; yet the middle classes are placed under equally favourable conditions of life for the perfect development of the body. Cook re- marks that the superiority in personal appearance “ which is observable in the erees or nobles in all the “ other islands (of the Pacific) is found in the Sandwich “ islands ; but this may be chiefly due to their better food and manner of life.
The old traveller Chardin, in describing the Persians, says their “blood is now highly refined by frequent
Chap. XX.
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“intermixtures with the Georgians and Circassians, “ two nations which surpass all the world in personal “beauty. There is hardly a man of rank in Persia “ who is not born of a Georgian or Circassian mother.” He adds that they inherit their beauty, “ not from their “ ancestors, for without the above mixture, the men of “ rank in Persia, who are descendants of the Tartars, “would be extremely ugly.”1 Here is a more curious case : the priestesses who attended the temple of Venus Erycina at San-Giuliauo in Sicily, were selected for their beauty out of the whole of Greece; they were not festal virgins, and Quatrefages,2 wTho makes this state- ment, says that the women of San-Giuliano are famous at the present day as the most beautiful in the island, and are sought by artists as models. Hut it is obvious that the evidence in the above cases is doubtful.
The following case, though relating to savages, is well Worth giving from its curiosity. Mr. Winwood Eeade informs me that the Jollofs, a tribe of negroes on the West coast of Africa, “ are remarkable for their uni- “ formly fine appearance.” A friend of his asked one of these men, “ How is it that every one whom I meet is “ so fine-looking, not only your men, but your women ? 1’he Jollof answered, “ it is very easily explained : it “ has always been our custom to pick out our worse- “ looking slaves and to sell them.” It need hardly be added that with all savages female slaves serve as concubines. That this negro should have attributed, whether rightly or wrongly, the fine appearance of his tribe, to the long-continued elimination of the ugly
1 These quotations are taken from Lawrence (‘ Lectures on Physi- ology,’ &c. 1822, p. 393), who attributes the beauty of the upper classes in England to the men having long selected the more beautiful women.
2 “ Anthropologie,” ‘Bevue des Cours Scientifiques,’ Oct. 1868, p.
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women, is not so surprising as it may at first appear ; for I have elsewhere shewn3 that negroes fully appre- ciate the importance of selection in the breeding of their domestic animals, and I could give from Mr. lieade additional evidence on this head.
On the Ccmses which prevent or checlc the Action of Sexual Selection with Savages. — The chief causes are, firstly, so-called communal marriages or promiscuous intercourse ; secondly, infanticide, especially of female infants; thirdly, early betrothals; and lastly, the low estimation in which women are held, as mere slaves. These four points must be considered in some detail.
It is obvious that as long as the pairing of man, or of any other animal, is left to chance, with no choice exerted by either sex, there can be no sexual selection ; and no effect will be produced on the offspring by certain individuals having had an advantage over others in their courtship. Now it is asserted that there exist at the present day tribes which practise what Sir J. Lubbock by courtesy calls communal marriages ; that is, all the men and women in the tribe are husbands and wives to each other. The licentiousness of many savages is no doubt astonishingly great, but it seems to me that more evidence is requisite before we fully admit that their existing intercourse is absolutely promiscuous. Nevertheless all those who have most closely studied the subject,4 and whose judgment is worth much more
3 ‘The Variation of Animals and Plants under Domestication,’ vol. i. p. 207.
4 Sir J . Lubbock, ‘ The Origin of Civilisation,’ 1870, chap. iii. especi- ally p. (iO-67. Mr. M'Lennan, in his extrunely valuable work on ‘ Primitive Marriage, 1865, p. IG3, speaks of the union of the sexes “ in the earliest tim< s as loose, transitory, and in some degree pronvs- “ cuous.” Mr. M'Lennan and Sir J. Lubbock have collected much evidence on the extreme licentiousness of savages at the present time. Mr. L. 11. Morgan, in his interesting memoir on the classilicatory system
Chap. XX.
INTERFERING CAUSES.
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than mine, believe that communal marriage was the original and universal form throughout the world, in- cluding the intermarriage of brothers and sisters. Ihe indirect evidence in favour of this belief is extremely strong, and rests chiefly on the terms ot relationship which are employed between the members of the same tribe, implying a connection with the tribe alone, and not with either parent. But the subject is too large and complex for even an abstract to be here given, and I will confine myself to a few remarks. It is evident in the case of communal marriages, or where the marriage- tie is very loose, that the relationship of the child to its father cannot be known. But it seems almost incredible that the relationship of the child to its mother should ever have been completely ignored, especially as the women in most savage tribes nurse their infants for a long time. Accordingly in many cases the lines ot descent are traced through the mother alone, to the exclusion of the father. But in many other cases the terms employed express a connection with the tribe alone, to the exclusion even of the mother. It seems possible that the connection between the related mem- bers of the same barbarous tribe, exposed to all sorts of danger, might be so much more important, owing to the need of mutual protection and aid, than that between the mother and her child, as to lead to the sole use of terms expressive of the former relationships ; but Mr. Morgan is convinced that this view of the case is by no means sufficient.
The terms of relationship used in different parts ot
of relationship (‘ Uroc. American Acad, of Sciences,’ vol. vii. Feb. 1808, p. 475) concludes that polygamy and all forms of marriage during primeval times were essentially unknown. It appears, also, Irom bir •>. Lubbock’s work, that Bacliofen likewise believes that communal inter- course originally prevailed.
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sexual selection: man.
Pakt II.
tile world may be divided, according to the author just quoted, into two great classes, the classificatory and descriptive,— the latter being employed by us. ' It is the classificatory system which so strongly leads to the belief that communal and other extremely loose forms of marriage were originally universal. But as far as 1 can see, there is no necessity on this ground for be- lieving m absolutely promiscuous intercourse; and I am glad to find that this is Sir J. Lubbock’s view. Men and women, like many of the lower animals, mio-ht for- merly have entered into strict though temporary” unions tor each birth, and in this case nearly as much confusion would have arisen in the terms of relationship as in the case of promiscuous intercourse. As far as sexual selec- tion is concerned, all that is required is that choice should be exerted before the parents unite, and it signifies little whether the unions last for life or only for a season.
Besides the evidence derived from the terms of re- ationship, other lines of reasoning indicate the former wide prevalence of communal marriage. Sir J. Lub- bock ingeniously accounts6 for the strange and widely- extended habit of exogamy, -that is, the men of one tn le always taking wives from a distinct tribe.— by communism having been the original form of mar- riage ; so that a man never obtained a wife for himself un ess he captured her from a neighbouring and hostile tribe, and then she would naturally have become Ids sole and valuable property. Thus the practice of cap- turing wives might have arisen; and from the honour so gained might ultimately have become the universal habit. Vie can also, according to Sir J. Lubbock,5 thus understand “the necessity of expiation for mar-
' *° Briti^ Association ‘On the Social and It ligious Con-
dition of the Lower Race s of Man,’ 1870, p. 20.
Chap. XX.
INTERFERING CAUSES.
S61
“ wage as an infringement of tribal rites, since, accord- “ ing to old ideas, a man had no right to appropriate “ to himself that which belonged to the whole tribe.” Sir J. Lubbock further gives a most curious body of facts shewing that in old times high honour was be- stowed on women who were utterly licentious ; and this, as he explains, is intelligible, if we admit that pro- miscuous intercourse was the aboriginal and therefore long revered custom of the tribe.6
Although the manner of development of the mar- riage-tie is an obscure subject, as wo may infer from the divergent opinions on several points between the three authors who have studied it most closely, namely, Mr. Morgan, Mr. M'Lennan, and Sir J. Lubbock, yet from the foregoing and several other lines of evidence it seems certain that the habit of marriage has been gradu- ally developed, and that almost promiscuous intercourse "Was once extremely common throughout the world. Nevertheless from the analogy of the lower animals, more particularly of those which come nearest to man in the series, I cannot believe that absolutely promiscu- ous intercourse prevailed formerly, w hen man had hardly attained to his present rank in the zoological scale. Man, as I have attempted to shew, is certainly descended from some ape-like creature. With the existing Quad- ruinana, as far as their habits are known, the males of some species are monogamous, but live during only a Part of the year with the females, as seems to be the case with the Orang. Several kinds, as some of the Indian and American monkeys, are strictly monogam- ous, and associate all the year round with their wives. Others are polygamous, as the Gorilla and several
* ‘ Origin of Civilisation,’ 1870, p. 86. In the several works above 'looted there will be found copious evidence on relationship through the females alone, or with the tribe alone.
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American species, and each family lives separate. Even " lien this occurs, the families inhabiting the same district are probably to a certain extent social: the Chimpanzee, for instance, is occasionally met with in huge bands. Again, other species are polygamous, but several males, each with their own females, live associated in a body, as with several species of Baboons.7 We may indeed conclude from what we know of the jealousy of all male quadrupeds, armed, as many of them are, with special weapons for battling with their rivals, that promiscuous intercourse in a state of nature is extremely improbable. The pairing mav not last for life, but only for each birth; yet if the males which are the strongest and best able to defend or otherwise assist their females and young offspring, were to select the more attractive females, this would suffice for the work of sexual selection.
I here lore, il we look far enough back iu the stream of time, it is extremely improbable that primeval men and women lived promiscuously together. Judging from the social habits of man as he now exists, and from most savages being polygamists, the most probable view is that primeval man aboriginally lived in small communities, each with as many wives as he could support and obtain, whom he would have jealously guarded against all other men. Or he may have lived with several wives by himself, like the Gorilla ; for all the natives “agree that but one adult male is seen in a band ; when the young male grows up, a “ contest takes place for mastery, and the strongest, by
» Brehm (‘ Blast. Thierleben,’ B. i. p. 77) says Cynooephalus hama- dryas lives in great troops containing twice as many adult females as adult males. See Rengger on American polygamous species, and Owen ( Anat. of ‘Vertebrates,’ vol. iii, p, 746) on American monogamous species. Other references might he added.
Cjiap. XX.
INTERFERING CAUSES.
SG3
“ killing and driving out the others, establishes himself “ as the head of the community.” 8 The younger males, being thus expelled and wandering about, would, when at last successful in finding a partner, prevent too close interbreeding within the limits of the same family.
Although savages are now extremely licentious, and although communal marriages may formerly have largely prevailed, yet many tribes practise some form of marriage, but of a far more lax nature than with civilised nations. Polygamy, as just stated, is almost universally followed by the leading men in every tribe. Nevertheless there are tribes, standing almost at the bottom of the scale, which are strictly monogamous. This is the case with the Yeddahs ot Ceylon: they have a saying, according to Sir J. Lubbock,9 “ that “ death alone can separate husband and wife. An intelligent Kandyan chief, of course a polygamist, “ was perfectly scandalized at the utter barbarism of “ living with only one wife, and never parting until « separated by death.” It was, he said, “just like the “ Wanderoo monkeys.” Whether savages who now enter into some form of marriage, either polygamous or monogamous, have retained this habit from primeval times, or whether they have returned to some form of marriage, after passing through a stage of promiscuous intercourse, I will not pretend to conjecture.
Infanticide. — This practice is now very common throughout the world, and there is reason to believe that it prevailed much more extensively during former times.10 Baibarians find it difficult to support them-
8 Dr Savage, in 1 Boston Journal of Nat. Hist.’ vol. v. 1845-47, p. 423.
* • Prehistoric Times,’ 18G9, p. 424.
10 Mr. M'Lennan, ‘ Primitive Marriage, ’ 1865. See especially on exogamy and infanticide, p. lot), 138, 105,
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selves and their children, and it is a simple plan to kill their infants. In South America some tribes, as Azara states, formerly destroyed so many infants of both sexes, that they were on the point of extinction. In the Poly- nesian Islands women have been known to kill from four or five to even ten of their children ; and Ellis could not find a single woman who had not killed at least one. Wherever infanticide prevails the struggle for existence will be in so far less severe, and all the members of the tribe will have an almost equally good chance of rearing their few surviving children. In most cases a larger number of female than of male infants are destroyed, for it is obvious that the latter are of most value to the tribe, as they will when grown up aid in de- fending it, and can support themselves. But the trouble experienced by the women in rearing children, their consequent loss of beauty, the higher estimation set on them and their happier fate, when few in number, are assigned by the women themselves, and by various ob- observers, as additional motives for infanticide. In Australia, where female infanticide is still common, Sir G. Grey estimated the proportion of native women to men as one to three ; but others say as two to three. In a village on the eastern frontier of India, Colonel IVlacculloch found not a single female child.11
When, owing to female infanticide, the women of a tribe are few in number, the habit of capturing wives lroin neighbouring tribes would naturally arise. ° Sir J. Lubbock, however, as we have seen, attributes the prac- tice in chief part, to the former existence of communal marriage, and to the men having consequently captured
11 Dr. Gerland (‘ Ueber das Aussterben der Naturvolker ’ 1SG8) has collected much information on infanticide, see especially s 07 51 54. Azara (‘ Voyages,’ &c tom. ii. p. 94, 116) enters in detail on the motives, bee also M'Lennan (ibid. p. 139) for cases in India.
Chap. XX.
INTERFERING CAUSES.
365
women from other tribes to hold as their sole property. Additional causes might be assigned, such as the com- munities being very small, in which case, marriageable Women would often bo deficient. That the habit of capture was most extensively practised during former times, even by the ancestors of civilised nations, is clearly shewn by the preservation of many curious customs and ceremonies, of which Mr. M'Lennan has given a most interesting account. In our own mar- riages the “ best man ” seems originally to have been the chief abettor of the bridegroom in the act of cap- ture. Now as long as men habitually procured their wives through violence and craft, it is not probable that they would have selected the more attractive women ; they would have been too glad to have seized on any woman. But as soon as the practice of procuring wives from a distinct tribe was effected through barter, as now occurs in many places, the more attractive women would generally have been purchased. The incessant crossing, however, between tribe and tribe, which necessarily follows from any form ol this habit would have tended to keep all the people inhabiting the same country nearly uniform in character ; and this would have greatly interfered with the power of sexual selection in differentiating the tribes.
The scarcity of women, consequent on female infanti- cide, leads, also, to another practice, namely polyandry, which is still common in several parts of the world, and which formerly, as Mr. M‘Lennan believes, prevailed tdmost universally ; but this latter conclusion is doubted by Mr. Morgan and fc>ir J. Lubbock.12 Whenever two
1 Primitive Marriage,’ p. 208 ; Sir J. Lubbock, 1 Origin of Civilisa- tion,’ p. mo. See alto Mr, Morgan, loc. cit., on former prevalence of Polyandry.
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or more men are compelled to marry one woman, it is certain that all the women of the tribe will get married, and there will bo no selection by the men of the more attractive women. But under these circumstances the women no doubt will have the power of choice, and will prefer the more attractive men. Azam, for in- stance, describes how carefully a Guana woman bargains for all sorts ot privileges, before accepting some one or more husbands ; and the men in consequence take unusual care of their personal appearance.13 The very ugly men would perhaps altogether fail in getting a wife, or get one later in life, but the handsomer men, although the most successful in obtaining wives, would not, as far as we can see, leave more offspring to inherit their beauty than the less handsome husbands of the same women.
Early Betrothals and Slavery of Women. — With many savages it is the custom to betroth the females whilst mere infants ; and this would effectually prevent preference being exerted on either side according to persona] appearance. But it would not prevent the more attractive women from being afterwards stolen or taken by force from their husbands by the more powerful men ; and this often happens in Australia, America, and other parts of the world. The same con- sequences with reference to sexual selection would to a certain extent follow when women are valued almost exclusively as slaves or beasts of burden, as is the case with most savages. The men, however, at all times would prefer the handsomest slaves according to their standard of beauty.
W e thus see that several customs prevail with savages
18 ‘Voyages,’ &c. tom. ii. p. 92-95.
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MANNER OF ACTION.
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which would greatly interfere with, or completely stop, the action of sexual selection. On the other hand, the conditions of life to which savages are exposed, and some of their habits, are favourable to natural selection ; and this always comes into play together with sexual selection. Savages are known to suffer severely from recurrent famines ; they do not increase their food by artificial means ; they rarely refrain from marriage,14 and generally marry young. Consequently they must he subjected to occasional hard struggles for existence, and the favoured individuals will alone survive.
Turning to primeval times when men had only doubt- fully attained the rank of manhood, they would probably have lived, as already stated, either as polygamists or temporarily as monogamists. Their intercourse, judging from analogy, would not then have been promiscuous. They would, no doubt, have defended their females to the best of their power from enemies of all kinds, and Would probably have hunted for their subsistence, as Well as for that of their offspring. The most power- ful and able males would have succeeded best in the struggle for life and in obtaining attractive females. At this early period the progenitors of man, from having only feeble powers of reason, would not have looked forward to distant contingencies. They would have been governed more by their instincts and even less by their reason than are savages at the present day. They would not at that period have partially lost one °f the strongest of all instincts, common to all the lower uuimals, namely the love of their young offspring; and
14 Burcliell says (‘ Travels in S. Africa, vol. ii. 1824, p. 58), that among the wild nations of Southern Africa, neither men nor women ever pass their lives in a state of celibacy. Azara (‘ Voyages dans l’Amerique Mend.’ tom. ii. 1809, p. 21) makes precisely the same remark in regard to the wild Indians of South America.
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consequently they would not have practised infanticide. There would have been no artificial scarcity of women, and polyandry would not have been followed ; there would have been no early betrothals ; women would not have been valued as mere slaves ; both sexes, if the females as well as the males were permitted to exert any choice, would have chosen their partners, not for mental charms, or property, or social position, but almost solely from external appearance. All the adults would have married or paired, and all the offspring, as far as that was possible, would have been reared ; so that the struggle for existence would have been periodically severe to an extreme degree. Thus during these pri- mordial times all the conditions for sexual selection would have been much more favourable than at a later period, when man had advanced in his intellectual powers, but had retrograded in his instincts. Therefore, whatever influence sexual selection may have had in producing the differences between the races of man, and between man and the higher Quadrumana, this influence would have been much more powerful at a very remote period than at the present day.
On the Manner of Action of Sexual Selection with mankind. — With primeval men under the favourable conditions just stated, and with those savages who at the present time enter into any marriage tie (but subject to greater or less interference according as the habits of female infanticide, early betrothals, &c., are more or less practised), sexual selection will probably have acted in the following manner. The strongest and most vigorous men, — those who could best defend and hunt for their families, and during later times the chiefs or head-men, — those who were provided with the best weapons and who possessed the most property, such as
Chap. XX.
MANXES OP ACTION.
369
a larger number of dogs or other animals, would have succeeded in rearing a greater average number of off- spring, than would the weaker, poorer and lower members of the same tribes. There can, also, be no doubt that such men would generally have been able to select the more attractive women. At present the chiefs of nearly every tribe throughout the world suc- ceed in obtaining more than one wife. Until recently, as I hear from Mr. Mantel], almost every girl in New Zealand, who was pretty, or promised to be pretty, was tapu to some chief. With the Kafirs, as Mr. C. Hamilton states,15 “ the chiefs generally have the pick “ of the women for many miles round, and are most “ persevering in establishing or confirming their privi- lege.” We have seen that each race has its own style of beauty, and we know that it is natural to man to admire each characteristic point in his domestic ani- mals, dress, ornaments, and personal appearance, when carried a little beyond the common standard. If then the several foregoing propositions be admitted, and I cannot see that they are doubtful, it would be an in- explicable circumstance, if the selection of the more attractive women by the more powerful men of each tribe, who would rear on an average a greater number of children, did not after the lapse of many generations modify to a certain extent the character of the tribe.
With our domestic animals, when a foreign breed is introduced into a new country, or when a native breed is long and carefully attended to, either for use or ornament, it is found after several generations to have undergone, whenever the means of comparison exist, a greater or less amount of change. This follows from Unconscious selection during a long series of generations
15 ‘ Anthropological Review,’ Jan. 1870, p. xvi.
2 B
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— that is, the preservation of the most approved indivi- duals— without any wish or expectation of such a result on the part of the breeder. So again, if two careful breeders rear during many years animals of the same family, and do not compare them together or with a common standard, the animals are found after a time to have become to the surprise of their owners slightly different.16 Each breeder has impressed, as Yon Nathusius well expresses it, the character of his own mind — his own taste and judgment — on his animals. What reason, then, can be assigned why similar results should not follow from the long-con- tinued selection of the most admired women by those men of each tribe, who were able to rear to maturity the greater number of children? This would be un- conscious selection, for an effect would be produced, independently of any wish or expectation on the part of the men who preferred certain women to others.
Let us suppose the members of a tribe, in which some form of marriage was practised, to spread over an unoccupied continent ; they would soon split up into distinct hordes, which would be separated from each other by various barriers, and still more effectually by the incessant wars between all barbarous nations. The hordes would thus be exposed to slightly different con- ditions and habits of life, and would sooner or later come to differ in some small degree. As soon as this occurred, each isolated tribe would form for itself a slightly different standard of beauty ; 17 and then uu-
16 ‘The Variation of Animals and Danis under Domestication,’ vol. ii. p. 210-217.
17 An ingenious writer argues, from a comparison of the pictures of Raphael, Rubens, and modern French artists, that the idea of beauty is not absolutely the same even throughout Europe : see the ‘ Lives of Haydn and Mozart,’ by M. Bombet, English translat. p. 278.
Chap. XX.
MANNER OF ACTION.
371
conscious selection would come into action through the more powerful and leading savages preferring certain women to others. Thus the differences between the tribes, at first very slight, would gradually and inevi- tably be increased to a greater and greater degree.
With animals in a state of nature, many characters proper to the males, such as size, strength, special weapons, courage and pugnacity, have been acquired through the law of battle. The semi-human proge- nitors of man, like their allies the Quadrumana, will almost certainly have been thus modified ; and, as savages still fight for the possession of their women, a similar process of selection has probably gone on in a greater or less degree to the present day. Other cha- racters proper to the males of the lower animals, such as bright colours and various ornaments, have been acquired by the more attractive males having been preferred by the females. There are, however, excep- tional cases in which the males, instead of having been the selected, have been the selectors. We recognise such cases by the females having been rendered more highly ornamented than the males, — their ornamental characters having been transmitted exclusively or chiefly to their female offspring. One such case ha3 been described in the order to which man belongs, namely, with the Eliesus monkey.
Man is more powerful in body and mind than woman, and in the savage state he keeps her in a far more abject, state of bondage than does the male of any other animal; therefore it is not surprising that he should have gained the power of selection. Women are every- where conscious of the value of their beauty ; and when they have the means, they take more delight in deco- rating themselves with all sorts of ornaments than do
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Pabt II.
men. They borrow the plumes of male birds, with which nature decked this sex in order to charm the females. As women have long been selected for beauty, it is not surprising that some of the successive variations should have been transmitted in a limited manner; and consequently that women should have transmitted their beauty in a somewhat higher degree to their female than to their male offspring. Hence women have be- come more beautiful, as most persons will admit, than men. Women, however, certainly transmit most of their characters, including beauty, to their offspring of both sexes; so that the continued preference by the men of each race of the more attractive women, according to their standard of taste, would tend to modify in the same manner all the individuals of both sexes belonging to the race.
With respect to the other form of sexual selection (which with the lower animals is much the most com- mon), namely, when the females are the selectors, and accept only those males which excite or charm them most, we have reason to believe that it formerly acted on the progenitors of man. Man in all probability owes Ins beard, and perhaps some other characters, to" inhe- ritance from an ancient progenitor who gained in this manner his ornaments. But tin’s form of selection may have occasionally acted during later times; for in ut- teilj barbarous tribes the women have more power in choosing, rejecting, and tempting their lovers, or of after- wards changing their husbands, than might have been ex- pected. As this is a point of some importance, I will give in detail such evidence as I have been able to collect.
Hearne describes how a woman in one of the tribes of Arctic America repeatedly ran away from her hus- band and joined a beloved man ; and with the Charruas of S. America, as Azara states, the power of
Chap. XX.
MANNER OF ACTION.
6 i d
divorce is perfectly free. With the Abipones, when a man chooses a wife he bargains with the parents about the price. But “it frequently happens that the “ girl rescinds what has been agreed upon between the “ parents and the bridegroom, obstinately rejecting the “ very mention of marriage.” She often runs away, hides herself, and thus eludes the bridegroom. In the Fiji Islands the man seizes on the woman whom lie wishes for his wife by actual or pretended force ; but “ on reaching the home of her abductor, should she not “ approve of the match, she runs to some one who can “ protect her ; if, however, she is satisfied, the matter is “settled forthwith.” In Tierra del Fuego a young man first obtains the consent of the parents by doing them some service, and then he attempts to carry off the girl ; “ but if she is unwilling, she hides herself “in the woods until her admirer is heartily tired of “ looking for her, and gives up the pursuit ; but this “ seldom happens.” With the Kalmucks there is a regular race between the bride and bridegroom, the former having a fair start ; and Clarke “ was assured “ that no instance occurs ot a girl being caught, unless “ she has a partiality to the pursuer.” So with the wild tribes of the Malay archipelago there is a similar racing match ; and it appears from M. Bourien’s account, as Sir J. Lubbock remarks, that “ the race * is not to “ ‘ the swift, nor the battle to the strong,’ but to the “ young man who has the good fortune to please his “ intended bride.”
Turning to Africa: the Kafirs buy their wives, and girls are severely beaten by their fathers if they will not accept a chosen husband ; yet it is manifest from many facts given by the Kev. Mr. Shooter, that they have considerable power of choice. Thus very ugly, though rich men, have been known to fail in getting
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wives. The girls, before consenting to be betrothed, compel the men to shew themselves off, first in front and then behind, and “exhibit their paces.” They have been known to propose to a man, and they not rarely run away with a favoured lover. Witli the degraded bush-women of S. Africa, “when a girl has “grown up to womanhood without having been be- “ trothed, which, however, does not often happen, her “lover must gain her approbation, as well as tbit of
the pai ents. Mr. Win wood Eeade made inquiries for me with respect to the negroes of Western Africa, and he informs me that “the women, at least among “ tlie more intelligent Pagan tribes, have no difficulty “ in getting the husbands whom they may desire, al- “ though it is considered unwomanly to ask a man to “ marry them. They are quite capable of falling in “ love, and of forming tender, passionate, and faithful “ attachments.”
We thus see that with savages the women are not in quite so abject a state in relation to marriage as has often been supposed. They can tempt the men whom they prefer, and can sometimes reject those whom they dislike, either before or after marriage. Preference on the part of the women, steadily acting in any one direction, would ultimately affect the character of the tribe ; for the women would generally choose not merely the handsomer men, according to their standard of taste,
A*ara> Voyages, &e. tom. ii. p. 23. Dobrizhoffer, ‘An Account ot the Abipones, vol. n. 1822, p. 207. Williams on the Fiji Wanders, as quoted by Lubbock, Origin of Civilisation,’ 1870, p. 79. On the luegians, Amg and FitzRoy, ‘Voyages of the Adventure and Beagle vo . u. 1888. p. 182. On the Kalmucks, quoted by M‘Len- nan ‘ PramUve Homage, 1805, „ 32. On the Malays, Lubbock, ibid, p. 16. The Rev. J. bhooter, ‘On the Kafirs of Natal,’ 1857, p. 52-60. On the Bush-women, Burchell, ‘ Travels in S. Africa,’ vol ii 1824, p. 59. ’ '
Chap. XX.
ABSENCE OF HAIR.
375
but those who were at the same time best able to defend and support them. Such well-endowed pairs would commonly rear a larger number of offspring than the less well endowed. The same result would obviously follow in a still more marked manner if there was selec- tion on both sides ; that is if the more attractive, and at the same time more powerful men were to prefer, and were preferred by, the more attractive women. And these two forms of selection seem actually to have occurred, whether or not simultaneously, with mankind, especially during the earlier periods of our long history.
We will now consider in a little more detail, rela- tively to sexual selection, some of the characters which distinguish the several races of man from each other and from the lower animals, namely, the more or less complete absence of hair from the body and the coloui of the skin. We need say nothing about the great diversity in the shape of the features and of the skull between the different races, as we have seen iu the last chapter how different is the standard of beauty in these respects. These characters will therefore probably have been acted on through sexual selection ; but we have no means of judging, as far as I can see, whether they have been acted on chiefly through the male or female side. The musical faculties of man have likewise been already discussed.
Absence of Hair on Hie Body, and its Development on the Face and Head— From the presence of the woolly hair or lanugo on the human feetus, and of rudimentary hairs scattered over the body during maturity, we may infer that man is descended from some animal which was born hairy and remained so during life. The loss of hair is an inconvenience and probably an injury to
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man even under a hot climate, for lie is thus exposed to sudden chills, especially during wet weather. As Mr. Wallace remarks, the natives in all countries are glad to protect their naked backs and shoulders with some slight covering. No one supposes that the naked- ness of the skin is any direct advantage to man, so that his body cannot have been divested of hair through natural selection.1* Nor have we any grounds for be- lieving, as shewn in a former chapter, that this can be c ue to the direct action of the conditions to which man has long been exposed, or that it is the result of cor- related development.
The absence of hair on the body is to a certain extent a secondary sexual character; for in all parts of the world women are less hairy than men. Therefore we may reasonably suspect that this is a character which has been gained through sexual selection. We know that the faces of several species of monkeys, and large surfaces at the posterior end of the body in other spe- cies, have been denuded of hair; and' this we may safely attribute to sexual selection, for these surfaces are not only vividly coloured, but sometimes, as with the male mandrill and female rhesus, much more vividly in the one sex than in the other. As these animals gradually reach maturity the naked surfaces, as 1 am informed by Mr. Bartlett, grow larger, rela-
‘?°ntr,butloris t0 fl*o Theory of Natural Selection,’ 1870, p. 3-16. Mr. M allace believes (p. 350) “that some intelligent power has guided OT determined the development of man;” and he considers the hair- less conditmn of the shin as coming under this head. The Eev. T. Iv aebbing, m commenting on this view (‘ Transactions of Devonshire A soc. for Science, 18 1 0) remarks, that had Mr. Wallace “employed ills usual ingenuity on the question of man’s hairless skin, he might
„ ha™,ST P°f a ‘y °f its selection its superior beauty
or tlie health attaching to superior cleanliness/ 1
Chap. XX.
ABSENCE OF HAIR.
377
tively to the size of their bodies. The hair, however, appears to have been removed in these cases, not for the sake of nudity, but that the colour of the skin should be more fully displayed. So again with many birds the head and ueck have been divested of feathers through sexual selection, for the sake of exhibiting the brightly-coloured skin.
As woman has a less hairy body than man, and as this character is common to all races, we may con- clude that our female semi-human progenitors were probably first partially divested of hair ; and that this occurred at an extremely remote period before the several races had diverged from a common stock. As our female progenitors gradually accjuired this new character of nudity, they must have transmitted it in an almost equal degree to their young offspring of both sexes ; so that its transmission, as in the case of many ornaments with mammals and birds, has not been limited either by age or sex. There is nothing sur- prising in a partial loss of hair having been esteemed as ornamental by the ape-like progenitors of man, for 're have seen that with animals of all kinds innumerable strange characters have been thus esteemed, and have consequently been modified through sexual selection. Nor is it surprising that a character in a slight degree injurious should have been thus acquired ; for we know that this is the case with the plumes of some birds, and with the horns of some stags.
The females of certain anthropoid apes, as stated in a former chapter, are somewhat less hairy on the under surface than are the males ; and here we have what 'night have afforded a commencement for the process °f denudation. With respect to the completion of the Process through sexual selection, it is well to bear in mind the New' Zealand proverb, “there is no woman
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“ for a hairy man.” All who have seen photographs of the Siamese hairy family will admit how ludicrously hideous is the opposite extreme of excessive hairiness. Hence the Icing of Siam had to bribe a man to marry the first hairy woman in the family, who transmitted this character to her young offspring of both sexes.20
Some races are much more hairy than others, especi- ally on the male side; but it must not be assumed that the more hairy races, for instance Europeans, have re- tained a primordial condition more completely than have the naked races, such as the Kalmucks or Ame- ricans. It is a more probable view that the hairiness of the former is due to partial reversion, for characters which have long been inherited are always apt to re- turn. A curious case has been recorded, by Pi nel, of an idiot, degraded to the level of a brute, whose back, loins, and shoulders were covered with hair, one or two inches in length. Some other analogous cases are like- wise known. It does not appear that a cold climate has been influential in leading to this kind of rever- sion ; excepting perhaps with the negroes, who have been reared during several generations, in the United States,21 and possibly with the Ainos, who inhabit the
20 1 The Variation of Animals and Plants under Domestication,’ vol. ii. 1868, p. 327.
21 ‘ Investigations into Military and Anthropological Statistics of American Soldiers,’ by B. A. Gould, 1869; p. 568 Observations were carefully made on the pilosity of 212!) black and coloured soldiers, whilst they were bathing; and by looking to the published table, “ it “ is manifest at a glance that there is hut little, if any, difference “ between the white and the black races in tliis respect.” It is, how- ever, certain that negroes in their native and much hotter land of Africa, have remarkably smooth bodies. It should be particularly observed, that pure blacks and mulattops were included in the above enumeration ; and tin's is an unfortunate circumstance, as in accordance with the principle, the truth of which I liavo elsewhere proved, crossed races would be eminently liable to revert to the primordial hairy character of their early ape-like progenitors.
Chap. XX.
BEAEDS.
379
northern islands of the Japan archipelago. But the laws of inheritance are so complex than we can seldom understand their action. If the greater hairiness of certain races be the result of reversion, unchecked by any form of selection, the extreme variability of this character, even within the limits of the same race, ceases to be remarkable.
With respect to the beard, if we turn to our best guide, namely the Quadrumana, we find beards equally well developed in both sexes of many species, but in others, either confined to the males, or more developed in them than in the females. From this fact, and from the curious arrangement, as well as the bright colours, of the hair about the heads of many monkeys, it is highly probable, as before explained, that the males first acquired their beards as an ornament through sexual selection, transmitting them in most cases, in an equal or nearly equal degree, to their offspring of both sexes. We know from Eschricht22 that with mankind, the female as well as the male foetus is furnished with much hair on the face, especially round the mouth ; and this indicates that we are descended from a progenitor, of which both sexes were bearded. It appears therefore nt first sight probable that man has retained his beard from a very early period, whilst woman lost her beard at the same time when her body became almost com- pletely divested of hair. Even the colour of the beard with mankind seems to have been inherited from an ape-like progenitor; for when there is any difference in tint between the hair of the head and the beard, the latter is lighter coloured in all monkeys and in man. There is less improbability in the men of the bearded
22 “Ueber die Kiclitung der Ilaare am Menschlickcn Korper,” in Muller’s ‘ Arcliiv fur Anat. und Pliye.’ 1837, s. 40.
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races having retained their beards from primordial times, than in the case of the hair on the body; for with those Quadrum ana, in which the male has a larger beard than that of the female, it is fully developed only at maturity, and the later stages of development may have been exclusively transmitted to mankind. We should then see what is actually the case, namely, our male children, before they arrive at maturity, as destitute ot beards as are our female children. On the other hand the great variability of the beard within the limits ot the same race and in different races indi- cates that reversion has come into action. However this may be, we must not overlook the part which sexual selection may have played even during later times; tor we know that with savages, the men of the beardless races take infinite pains in eradicating every hair from their faces, as something odious, whilst the men of the bearded races feel the greatest pride in their beards. The women, no doubt, participate in these feelings, and if so sexual selection can hardly have failed to have effected something in the course of later times.23
It is rather difficult to form a judgment how the long
Mi'. Spvoat (‘Scenes and Studies of Savage Life,’ 1SG8, p. 25) suggests, with reference to the beardless natives of Vancouver's Island, that the custom of plucking out tiro hairs on the face, “ continued from one generation to another, would perhaps at last produce a race “ distinguishable by a thin and straggling growth of beard.” But tho custom would not liuvo arisen until the. bi ard had already become, from some independent cause, greatly reduced. Nor liavo we any direct evidence that the continued eradication of the hair would load to any inherited effect. Owing to this cause of doubt, I havo uot hitherto alluded to the belief held by some distinguished ethnologists, for in- stance M. Gosse of Geneva, that artificial modifications of tho skull tend to be Inherited. I have no wish to dispute this conclusion ; and we now know from Dr. Brown-Sequard’s remarkable observations, espe- cially those recently communicated (1870) to the British Association, that with guinea-pigs the effects of operations are inherited.
CnAr. XX.
COLOUR OP SKIN.
381
hair on our heads became developed. Eschricht 24 states that in the human foetus the hair on the face during the fifth month is louger than that on the head ; and this indicates that our semi-human progenitors were not furnished with long tresses, which consequently must have been a late acquisition. This is likewise indicated by the extraordinary difference in the length of the hair in the different races ; in the negro the hair forms a mere curly mat ; with us it is of great length, and with the American natives it not rarely reaches to the ground. Some species of Semnopithecus have their heads covered with moderately long hair, and this pro- bably serves as an ornament and was acquired through sexual selection. The same view may be extended to mankind, for we know that long tresses are now and "ere formerly much admired, as may be observed in the "orks of almost every poet ; St. Paul says, if a woman “ have long hair, it is a glory to her ; ” and we have seen that in North America a chief was elected solely from the length of his hair.
Colour of the Skin. — The best kind of evidence that the colour of the skin has been modified through sexual selection is wanting in the case ol mankind ; for the sexes do not differ in this respect, or only slightly and doubtfully. On the other hand we know from many facts already given that the colour of the skin is re- garded by the men of all races as a highly important dement in their beauty ; so that it is a character which "Tonld be likely to be modified through selection, as has occurred in innumerable instances with the lower ani- mals. It seems at first sight a monstrous supposition that the jet blackness of the negro has been gained
24 1 Ucber die Riclitung,’ ibid. s. 40.
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Part II.
through sexual selection ; hut this view is supported by various analogies, and we know that negroes admire their own blackness. With mammals, when the sexes differ in colour, the male is often black or much darker than the female ; and it depends merely on the form of inheritance whether this or any other tint shall be trans- mitted to both sexes or to one alone. The resemblance of Pithecia saianas with his jet black skin, white rolling eyeballs, and hair parted on the top of the head, to a negro in miniature, is almost ludicrous.
The colour of the face differs much more widely in the various kinds of monkeys than it does in the races of man ; and we have good reason to believe that the red, blue, orange, almost white and black tints of their skin, even when common to both sexes, and the bright colours of their fur, as well as the ornamental tufts of hair about the head, have all been acquired through sexual selection. As the newly-born infants of the most distinct races do not differ nearly as much in colour as do the adults, although their bodies are com- pletely destitute of hair, we have some slight indication that the tints of the different races were acquired sub- sequently to the removal of the hair, which, as before stated, must have occurred at a very early period.
Summary. — We may conclude that the greater size, strength, courage, pugnacity, and even energy of man, in comparison with the same qualities in woman, were acquired during primeval times, and have subsequently been augmented, chielly through the contests of rival males for the possession of the females. The greater intellectual vigour and power of invention in man is probably due to natural selection combined with the inherited effects of habit, for the most able men will have succeeded best in defending and providing for
Chap. XX.
SUMMARY.
383
themselves, their wives and offspring. As far as the extreme intricacy of the subject permits us to judge, it appears that our male ape-like progenitors acquired their beards as an ornament to charm or excite the opposite sex, and transmitted them to man as lie now exists. The females apparently were first denuded of hair in like manner as a sexual ornament ; but they transmitted this character almost equally to both sexes. It is not improbable that the females were modified in other respects for the same purpose and through the same means ; so that women have acquired sweeter Voices and become more beautiful than men.
It deserves particular attention that with mankind all the conditions for sexual selection were much more favourable, during a very early period, when man had only just attained to the rank of manhood, than during later times. For he would then, as we may safely con- clude, have been guided more by his instinctive passions, and less by foresight or reason. He would not then have been so utterly licentious as many savages now are; and each male would have jealously guarded his wife or wives. He would not then have practised infanticide; aor valued his wives merely as useful slaves ; nor have been betrothed to them during infancy. Hence we may infer that the races of men were differentiated, as far as Sexual selection is concerned, in chief part during a very remote epoch ; and this conclusion throws light on the remarkable fact that at the most ancient period, of which We have as vet obtained any record, the races of man had already come to diner nearly or quite as much as they do at the present day.
The views here advanced, on the part which sexual selection has played in the history of man, want scien- tific precision. He wdio does not admit this agency in the case of the lower animals, will properly disregard
384
sexual selection: man.
Part II.
all that I have written in the later chapters on man. We cannot positively say that this character, but not that, has been thus modified ; it has, however, been shewn that the races of man differ from each other and from their nearest allies amongst the lower animals, in certain characters which are of no service to them in their ordinary habits of life, and which it is extremely probable would have been modified through sexual selec- tion. We have seen that with the lowest savages the people of each tribe admire their own characteristic qualities, — the shape of the head and face, the square- ness of the cheek-bones, the prominence or depression of the nose, the colour of the skin, the length of the hair on the head, the absence of lmir on the face and body, or the presence of a great beard, and so forth. Hence these and other such points could hardly fail to have been slowly and gradually exaggerated from the more powerful and able men in each tribe, who would succeed in rearing the largest number of offspring, hav- ing selected during many generations as their w'ives the most strongly characterised and therefore most attrac- tive women. For my own part I conclude that of all the causes which have led to the differences in external appearance between the races of man, and to a certain extent between man and the lower animals, sexual selection has been by far the most efficient.
Chap. XXI. GENERAL SUMMARY AND CONCLUSION. 385
CHAPTER XXI.
General Summary and Conclusion.
Main conclusion that man is descended, from some lower form — Manner of development — Genealogy of man — Intellectual and moral faculties — Sexual selection — Concluding remarks.
A brief summary will here be sufficient to recall to the leader’s mind the more salient points in this work. Many of the views which have been advanced are highly speculative, and some no doubt will prove erroneous ; hut I have in every case given the reasons which have led me to oue view rather than to another. It seemed worth while to try how far the principle of evolution Would throw light on some of the more complex pro- blems in the natural history of man. False facts are highly injurious to the progress of science, for they often long endure; but false views, if supported by some evidence, do little barm, as every one takes a salutary pleasure in proving tbeir falseness; aud when this is hone, one path towards error is closed and the road to truth is often at the same time opened.
The main conclusion arrived at in this work, and now held by many naturalists wdio are well competent to h’rm a sound judgment, is that man is descended from 80 111 e less highly organised form. The grounds upon "hich this conclusion rests will never be shaken, for the °lose similarity between man and the lower animals in ornbryonic development, as well as in innumerable Points of structure and constitution, both of high and °f the most trifling importance, — the rudiments which Vol. ii. 2 c
386
GENERAL SUMMARY
Part II.
he retains, and the abnormal reversions to which he is occasionally liable, — are facts which cannot be dis- puted. They have long been known, but until recently they told us nothing with respect to the origin of man. Now when viewed by tlie light of our know- ledge of the whole organic world, their meaning is unmistakeable. The great principle of evolution stands up clear and firm, when these groups of facts are con- sidered in connection with others, such as the mutual affinities of the members of the same group, their geographical distribution in past and present times, and their geological succession. It is incredible that all these facts should speak falsely. He who is not content to look, like a savage, at the phenomena of nature as disconnected, cannot any longer believe that man is the work of a separate act of creation. He will be forced to admit that the close resemblance of the embryo of man to that, for instance, of a dog — the con- struction of his skull, limbs, and whole frame, indepen- dently of the uses to which the parts may bo put, on the same plan with that of other mammals — the occa- sional reappearance of various structures, for instance of several distinct muscles, which man does not nor- mally possess, but which are common to the Quadru- mana — and a crowd of analogous facts — all point in the plainest manner to the conclusion that man is the co-descendant with other mammals of a common pro- genitor.
We have seen that man incessantly presents indi- vidual differences in all parts of his body and in his mental faculties. These differences or variations seem to be induced by the same general causes, and to obey the same laws as with the lower animals. In both cases similar laws of inheritance prevail. Man tends to increase at a greater rate than his means of subsistence ;
Chap. XXI.
AND CONCLUDING REMARKS.
387
consequently lie is occasionally subjected to a severe struggle for existence, and natural selection will have effected whatever lies within its scope. A succession of strongly-marked variations of a similar nature are by no means requisite ; slight fluctuating differences in the individual suffice for the work of natural selec- tion. Wo may feel assured that the inherited effects of the long-continued use or disuse of parts will have done much in the same direction with natural selection. Modifications formerly of importance, though no longer of any special use, will he long inherited. When one part is modified, other parts will change through the principle of correlation, of which we have instances in many curious cases of correlated monstrosities. Some- thing may be attributed to the direct and definite action of the surrounding conditions of life, such as abundant food, heat, or moisture ; and lastly, many characters of slight physiological importance, some in- deed of considerable importance, have been gained through sexual selection.
No doubt man, as well as every other animal, pre- sents structures, which as far as we can judge with °ar little knowledge, are not now of any service to him, nor have been so during any former period of his existence, either in relation to his general conditions of b'fe, or of one sex to the other. Such structures cannot be accounted for by any form of selection, or by the 1 Merited effects of the use and disuse of parts. We know, however, that many strange and strongly-marked Peculiarities of structure occasionally appear in our domesticated productions, and if the unknown causes "hick produce them were to act more uniformly, they "°uld probably become common to all the individuals
the species. We may hope hereafter to understand Something about the causes of such occasional modi-
2 c 2
388 GENERAL SUMMARY Part II.
fications, especially through the study of monstrosities : hence the labours of experimentalists, such as those of M. Camille Dareste, are full of promise for the future. In the greater number of cases we can only say that the cause of each slight variation and of each monstrosity lies much more in the nature or constitution of the organism, than in the nature of the surrounding con- ditions ; though new and changed conditions certainly play an important part in exciting organic changes of all kinds.
Through the means just specified, aided perhaps by others as yet undiscovered, man has been raised to his present state. But since he attained to the rank of manhood, he has diverged into distinct races, or as they may he more appropriately called sub-specios. Some of these, for instance the Negro and European, are so distinct that, if specimens had been brought to a natu- ralist without any further information, they would un- doubtedly have been considered by him as good and true species. Nevertheless all the races agree in so many unimportant details of structure and in so many mental peculiarities, that these can be accounted for only through inheritance from a common progenitor ; and a progenitor thus characterised would probably nave deserved to rank as man.
It must not be supposed that the divergence of each race from the other races, and of all the races from a common stock, can be traced back to any one pair of progenitors. On the contrary, at every stage in the process of modification, all the individuals which were in any way best fitted for their conditions of life, though in different degrees, would have survived in greater numbers than the less well fitted. The pro- cess would have been like that followed by man, when he does not intentionally select particular individuals*
Chap. XXI.
AND CONCLUDING EEMABKS.
389
but breeds from all the superior and neglects all the inferior individuals. He thus slowly but surely modi- fies his stock, and unconsciously forms a new strain. So with respect to modifications, acquired indepen- dently of selection, and due to variations arising from the nature of the organism and the action of the sur- rounding conditions, or from changed habits of life, no single pair will have been modified in a much greater de gree than the other pairs which inhabit the same Country, for all will have been continually blended through free intercrossing.
By considering the embryological structure of man, - — the homologies which he presents with the lower animals, — the rudiments which he retains, — and the reversions to which he is liable, we can partly recall in imagination the former condition of our early pro- genitors ; and can approximately place them in their proper position in the zoological series. We thus learn that man is descended from a hairy quadruped, fur- nished with a tail and pointed ears, probably arboreal in its habits, and an inhabitant of the Old World. This creature, if its whole structure had been examined by a naturalist, would have been classed amongst the Quadrumana, as surely as would the common and still more ancient progenitor of the Old and New World monkeys. The Quadrumana and all the higher mam- mals are probably derived from an ancient marsupial animal, and this through a Jong line of diversified forms, either from some reptile-like or some amphibian- i'ke creature, and this again from some fish-like animal. b> the dim obscurity of the past we can see that the oarly progenitor of all the Vertebrata must have been an aquatic animal, provided with branchiae, witli the two ^exes united in the same individual, and with the most 'niportant organs of the body (such as the brain and
390
GENERAL SUMMARY
Part II.
heart) imperfectly developed. This animal seems to have been more like the larvae of our existing marine Ascidians than any other known form.
The greatest difficulty which presents itself, when we are driven to the above conclusion on the origin of man, is the high standard of intellectual power and of moral disposition which he has attained. But every one who admits the general principle of evolution, must see that the mental powers of the higher animals, which are the same in kind with those of mankind, though so different in degree, are capable of advancement. Thus the interval between the mental powers of one of the higher apes and of a fish, or between those of an ant and scale-insect, is immense. The develop- ment of these powers hi animals does not offer any special difficulty; for with our domesticated animals, the mental faculties are certainly variable, and the variations are inherited. No one doubts that these faculties are of the utmost importance to animals in a state of nature. Therefore the conditions are favour- able for their development through natural selection. The same conclusion may be extended to man; the intellect must have been all-important to him, even at a very remote period, enabling him to use language, to invent and make weapons, tools, traps, &c. ; bv which means, in combination with his social habits, he long ago became the most dominant of all living creatures.
A great stride in the development of the intellect will have followed, as soon as, through a previous consi- derable advance, the half-art and half-instinct of lan- guage came into use ; for the continued use of language will have reacted on the brain, and produced an in- herited effect ; and this again will have reacted on the improvement of language. The large size of the brain
Chap. XXI.
AND CONCLUDING REMARKS.
391
oi man, in comparison with that of the lower animals, relatively to the size of their bodies, may be attributed in chief part, as Mr. Chauneey Wright has well re- marked,1 to the early use of some simple form of language,- — that wonderful engine which affixes signs to all sorts of objects and qualities, and excites trains of thought which would never arise from the mere im- pression of the senses, and if they did arise could not be followed out. The higher intellectual powers of man, such as those of ratiocination, abstraction, self- consciousness, &c., will have followed from the con- tinued improvement of other mental faculties ; but without considerable culture of the mind, both in the race and in the individual, it is doubtful whether these high powers would be exercised, and thus fully attained.
The development of the moral qualities is a more interesting and difficult problem. Their foundation lies in the social instincts, including in this term the family tips. These instincts are of a highly complex nature, and in the case of the lower animals give special tendencies towards certain definite actions ; but tlie more important elements for us are love, and the distinct emotion of sympathy. Animals endowed with the social instincts take pleasure in each other’s com- pany, warn each other of danger, defend and aid each other in many ways. These instincts arc not extended to all the individuals of the species, but. only to those of the same community. As they are highly beneficial to the species, they have in all probability been acquired through natural selection.
O
A moral being is one who is capable of reflecting on bis past actions and their motives, — of approving of
1 On the “ Limits of Natural Selection,” in the ‘ North American Review,’ Oct. 1870, p. 295.
392
GENERAL SUMMARY
Part II.
some and disapproving of others; and the fact that man is the one being who with certainty can be thus designated makes the greatest of all distinctions be- tween him and the lower animals. But in our third chapter I have endeavoured to shew that the moral sense follows, firstly, from the enduring and always present nature of the social instincts, in which respect man agrees with the lower animals ; secondly, from his appreciation of the approbation and disapprobation of his fellows, and thirdly, from his mental faculties being h%hly active and his impressions of past events ex- tiemely vivid, in which respects he differs from the lower animals. Owing to this condition of mind, man cannot avoid looking both backwards and forwards, and comparing past impressions. Hence after some temporary desire or passion has mastered his social in- stincts, ho will reflect and compare the now weakened impression of such past impulses, with the ever present social instincts ; and he will then feel that sense of dis- satisfaction which all unsatisfied instincts leave behind them. Consequently he resolves to act differently for the future — and this is conscience. Any instinct which is permanently stronger or more enduring than another, gives rise to a feeling which we express by saving that it ought to be obeyed. A pointer dog, if able to reflect on his past conduct, would say to himself, I ought (as indeed we say of him) to have pointed at that hare and not have yielded to the passing temptation of springing on and hunting it.
bocial animals are partly impelled by a wish to aid the members of the same community in a general manner, but more commonly to perform certain definite actions. Man is impelled by the same general wish to aid his fellows, but has few or no special instincts. He differs also from the lower animals in being able
Chap. XXI.
AND CONCLUDING REMARKS.
393
to express his desires by words, which thus become the guide to the aid required aud bestowed. The motive to give aid is likewise much modified in man : it no longer consists solely of a blind instinctive impulse, but is largely influenced by the praise or blame of his fellow men. Both the appreciation and the bestowal of praise and blame rest on sympathy ; and this emotion, as we have seen, is one of the most important elements of the social instincts. Sympathy, though gained as an instinct, is also much strengthened by exercise or habit. As all men desire their own happiness, praise or blame is bestowed on actions and motives, according as they lead to this end ; and as happiness is an essential part of the general good, the greatest-happiness principle indirectly serves as a nearly safe standard of right and wrong. As the reasoning- powers advance and experience is gained, the more remote effects of certain lines of conduct on the character of the individual, and on the general good, are perceived ; and then the self-regarding virtues, from coming within the scope of public opinion, receive praise, and their opposites receive blame. But with the less civilised nations reason often errs, and many bad customs and base superstitions come within the same scope, and consequently are esteemed as high virtues, and their breach as heavy crimes.
The moral faculties are generally esteemed, and with justice, as of higher value than the intellectual powers. But we should always bear in mind that the activity of the mind in vividly recalling past impressions is one of the fundamental though secondary bases of conscience. This fact affords the strongest argument for educating and stimulating in all possible ways the intellectual faculties of every human being. No doubt a man with a torpid mind, if his social affections and sympathies are
394
GENERAL SUMMARY
Part II.
well developed, will be led to good actions, and may have a fairly sensitive conscience. But whatever ren- ders the imagination of men more vivid and strengthens the habit of recalling and comparing past impressions, will make the conscience more sensitive, and may even compensate to a certain extent for weak social affections and sympathies.
Ihe moral nature of man has reached the highest stand aid as yet attained, partly through the advance- ment of the reasoning powers and consequently of a just public opinion, but especially through the sympathies being rendered more tender and widely diffused through the effects of habit, example, instruction, and reflection. It is not improbable that virtuous tendencies may through long practice be inherited. With the more civilised races, the conviction of the existence of an all-seeing Deity has had a potent influence on the advancement of morality. Ultimately man no longer accepts the praise or blame of his fellows as his chief guide, though few escape this influence, but his habi- tual convictions controlled by reason afford him the safest rule. His conscience then becomes his supreme judge and monitor. Nevertheless the first foundation or origin of the moral sense lies in the social instincts, including sympathy ; and these instincts no doubt were primarily gained, as in the case of the lower animals, through natural selection.
The belief in God has often been advanced as not only the greatest, but the most complete of all the distinctions between man and the lower animals. It is however impossible, as we have seen, to maintain that this belief is innate or instinctive in man. On the other hand a belief in all-pervading spiritual agencies seems to be universal ; and apparently follows from a
Ciiap. XXI.
AND CONCLUDING REMARKS.
395
considerable advance in the reasoning powers of man, and from a still greater advance in his faculties of im- agination, curiosity and wonder. I am aware that the assumed instinctive belief in God has been used by many persons as an argument for His existence. But this is a rash argument, as we should thus be compelled to believe in the existence of many cruel and malignant spirits, possessing only a little more power than man ; for the belief in them is far more general than of a beneficent Deity. The idea of a universal and bene- ficent Creator of the universe does not seem to arise in the mind of man, until he has been elevated by long- continued culture.
He who believes in the advancement of man from some lowly-organised form, will naturally ask how does this bear on the belief in the immortality of the soul. The barbarous races of man, as Sir J. Lubbock has shewn, possess no clear belief ol this kind; but argu- ments derived from the primeval beliefs of savages are, as we have just seen, of little or no avail. Few persons .feel any anxiety from the impossibility of determining at what precise period in the development of the indi- vidual, from the first trace of the minute germinal vesicle to the child either before or after birth, man becomes an immortal being; and there is no greater cause for anxiety because the period in the gradually ascending organic scale cannot possibly be determined.2
I am aware that the conclusions arrived at in this work will be denounced by some as highly irreligious; but he who thus denounces them is bound to shew why it is more irreligious to explain the origin of man as a distinct species by descent from some lower form,
2 The Rev. J. A. Picton gives a discussion to this effect in his 1 New Theories and the Old Faith/ 1870.
390
GENERAL SUMMARY
Part II.
through the laws of variation and natural selection, than to explain the birth of the individual through the laws of ordinary reproduction. The birth both of the species and of the individual are equally parts of that grand sequence of events, which our minds refuse to accept as the result of blind chance. The understand- ing revolts at such a conclusion, whether or not we are able to believe that every slight variation of struc- ture,—the union of each pair in marriage, — the disse- mination ol each seed, — and other such events, have all been ordained for some special purpose.
Sexual selection has been treated at great length in these volumes; for, ns I have attempted to shew, it has played an important part in the history of the organic world. As summaries have been given to each chapter, it would be superfluous here to add a detailed sum- mary. I am aware that much remains doubtful, but I have endeavoured to give a fair view of the whole case. In the lower divisions of the animal kingdom, sexual selection seems to have done nothing: such animals are often affixed for life to the same spot, or have the two sexes combined in the same individual, or what is still more important, their perceptive and intellectual faculties are not sufficiently advanced to allow of the feelings of love and jealousy, or of the exertion of choice. When, however, we come to the Arthropoda and Yerte- brata, even to the lowest classes in these two great Sub- Kingdoms, sexual selection has effected much ; and it deserves notice that we here find the intellectual facul- ties developed, but in two very distinct lines, to the highest standard, namely in the Hymenoptera (ants, bees, &c.) amongst the Arthropoda, and in the Mam- malia, including man, amongst the Yertebrata.
In the most distinct classes of the animal kingdom,
O 7
Ciiap. XXI.
AND CONCLUDING REM AUKS.
397
with mammals, birds, reptiles, fishes, insects, and even crustaceans, the differences between the sexes follow almost exactly the same rules. The males are almost always the wooers ; and they alone are armed with spe- cial weapons for fighting with their rivals. They are generally stronger and larger than the females, and are endowed with the requisite qualities of courage and pug- nacity. They are provided, either exclusively or in a much higher degree than the females, with organs for producing vocal or instrumental music, and with odori- ferous glands. They are ornamented with infinitely diversified appendages, and with the most brilliant or conspicuous colours, often arranged in elegant patterns, W'hilst the females are left unadorned. When the sexes differ in more important structures, it is the male which is provided with special sense-organs for discovering the female, with locomotive organs for reaching her, and often with prehensile organs for holding her. These various structures for securing or charming the female are often developed in the male during only part of the year, namely the breeding season. They have in many cases been transferred in a greater or less degree to the females; and in the latter case they appear in her as mere rudiments. They are lost by the males after emasculation. Generally they are not developed in the male during early youth, but appear a short time before the age for reproduction. Hence in most cases the young of both sexes resemble each other ; and the female resembles her young offspring through- out life. In almost every great class a few anomalous cases occur in which there has been an almost complete transposition of the characters proper to the two sexes ; the females assuming characters which properly belong to the males. This surprising uniformity in the laws regulating the differences between the sexes in so many
398
GENERAL SUMMARY
Part II.
and such widely separated classes, is intelligible if we admit the action throughout all the higher divisions of the animal kingdom of one common cause, namely sexual selection.
Sexual selection depends on the success of certain individuals over others of the same sex in relation to the propagation of the species ; whilst natural selection depends on the success of both sexes, at all ages, in re- lation to the general conditions of life. The sexual struggle is of two kinds; in the one it is between the individuals of the same sex, generally the male sex, in order to drive away or kill their rivals, the females remaining passive; whilst in the other, the struggle is likewise between the individuals of the same sex, in order to excite or charm those of the opposite sex, generally the females, which no longer remain passive, but select the more agreeable partners. This latter kind of selection is closely analogous to that which man unintentionally, yet effectually, brings to bear on his domesticated productions, when he continues for a lon^ tune choosing the most pleasing or useful individuals, without any wish to modify the breed.
The laws of inheritance determine whether charac- ters gained through sexual selection by either sex shall be transmitted to the same sex, or to both sexes ; as well as the age at which they shall be developed. It appears that variations which arise late in life are com- monly transmitted to one and the same sex. Vari- ability is the necessary basis for the action of selection, and is wholly independent of it. It follows from this, that variations of the same general nature have often been taken advantage of and accumulated through sexual selection in relation to the propagation of the species, and through natural selection in relation to the general purposes of life. Hence secondary sexual cha-
Ciiap. XXI.
AND CONCLUDING REMARKS.
399
racters, when equally transmitted to both sexes can be distinguished from ordinary specific characters only by the light of analogy. The modifications acquired through sexual selection are often so strongly pronounced that the two sexes have frequently been ranked as distinct species, or even as distinct genera. Such strongly- marked differences must be in some manner highly im- portant; and we know that they have been acquired in some instances at the cost not only of inconvenience, but of exposure to actual danger.
The belief in the power of sexual selection rests chiefly on the following considerations. The characters which we have the best reason for supposing to have been thus acquired are confined to one sex ; and this alone renders it probable that they are in some way connected with the act of reproduction. These charac- ters in innumerable instances are fully developed only at maturity ; and often during only a part of the year, which is always the breeding-season. The males (pass- ing over a few exceptional cases) are the most active in courtship; they are the best armed, and are rendered the most attractive in various ways. It is to be espe- cially observed that the males display their attractions with elaborate care in the presence of the females ; and that they rarely or never display them excepting during the season of love. It is incredible that all this display should be purposeless. Lastly we have distinct evidence with some quadrupeds and birds that the indi- viduals of the oDe sex are capable of feeling a strong antipathy or preference for certain individuals of the opposite sex.
Bearing these facts in mind, and not forgetting the marked results of man’s unconscious selection, it seems to me almost certain that if the individuals of one sex were during a long series of generations to prefer pair-
400
GENERAL SUMMARY
Part II.
ing with certain individuals of the other sex, charac- terised in some peculiar manner, the offspring would slowly hut surely become modified in this same manner. I have not attempted to conceal that, excepting when the males are more numerous than the females, or when polygamy prevails, it is doubtful how the more attrac- tive males succeed in leaving a larger number of off- spiing to inherit their superiority in ornaments or other charms than the less attractive males; but I have shewn that this would probably follow from the females,— espe- cially the more vigorous females which would be the first to breed, preferring not only the more attractive but at the same time the more vigorous and victorious males.
Although we have some positive evidence that birds appreciate bright and beautiful objects, as with the Bower-birds of Australia, and although they certainly appreciate the power of song, yet I fully admit that it is an astonishing fact that the females of many birds and some mammals should be endowed with sufficient taste for what lias apparently been effected through sexual selection ; and this is even more astonishing in the case of reptiles, fish, and insects. But we really know very little about the minds of the lower animals. It cannot be supposed that male Birds of Paradise or eacocks, for instance, should take so much pains in erecting, spreading, and vibrating their beautiful plumes before the females for no purpose. We should remember t le act given on excellent authority in a former chap- ter, namely that several peahens, when debarred from an admired male, remained widows during a whole season rather than pair with another bird.
Nevertheless I know of no fact in natural history more wonderful than that the female Argus pheasant should be able to appreciate the exquisite shading of the ball-and-socket ornaments and the elegant patterns
Ciup. XXI.
AND CONCLUDING REMARKS.
401
on the wing-feathers of the male. He who thinks that the male was created as lie now exists must admit that the great plumes, which prevent the wings from being Used for flight, and which, as well as the primary feathers, are displayed in a manner quite peculiar to this one species during the act of courtship, and at no other time, were given to him as an ornament. If so, he must likewise admit that the female was created and endowed with the capacity of appreciating such orna- ments. I differ only in the conviction that the male Argus pheasant acquired his beauty gradually, through the females having preferred during many genera-, tions the more highly ornamented males ; the aesthetic capacity of the females having been advanced through exercise or habit in the same manner as our own taste is gradually improved. In the male, through the for- tunate chance of a few feathers not having been modified, We can distinctly see how simple spots with a little fulvous shading on one side might have been de- veloped by small and graduated steps into the won- derful ball-and-socket ornaments ; and it is probable that they were actually thus developed.
Everyone who admits the principle of evolution, and yet feels great difficulty in admitting that female mammals, birds, reptiles, and fish, could have acquired the high standard of taste which is implied by the beauty of the males, and which generally coincides with our own standard, should reflect that in each member °t the vertebrate series the nerve-cells of the brain are the direct offshoots of those possessed by the common progenitor of the whole group. It thus becomes intel- ligible that the brain and mental faculties should be capable under similar conditions of nearly the same course of development, and consequently of performing nearly the same functions.
VOL. II. 2 D
402
GENERAL SUMMARY.
Part II.
41ie reader who has taken the trouble to go through the several chapters devoted to sexual selection, will be able to judge how far the conclusions at which I have ar- rived are supported by sufficient evidence. If he accepts these conclusions, he may, I think, safely extend them to mankind ; but it would be superfluous here to repeat what I have so lately said on the manner in which sexual selection has apparently acted on both the male and female side, causing the two sexes of man to differ in body and mind, and the several races to differ from each other in various characters, as well as from their ancient and lowly-organised progenitors.
He who admits the principle of sexual selection will be led to the remarkable conclusion that the cerebral system not only regulates most of the existing functions oi the body, but has indirectly influenced the progressive development of various bodily structures and of certain mental qualities. Courage, pugnacity, perseverance, strength and size of body, weapons of all kinds, musical organs, both vocal and instrumental, bright colours, stripes and marks, and ornamental appendages, have all been indirectly gained by the one sex or the other, through the influence of love and jealousy, through the appreciation of the beautiful in sound, colour or form, and through the exertion of a choice ; and these powers of the mind manifestly depend on the development of the cerebral system.
Man scans with scrupulous care the character and pedigree ot his horses, cattle, and dogs before he matches them ; but when he comes to his own marriage he rarely, or never, takes any such care. He is impelled by nearly the same motives as are the lower animals when left to their own free choice, though he is in so far superior to them that he highly values mental charms
Ciiap. XXI.
AND CONCLUDING REMARKS.
403
and virtues. On the other hand he is strongly attracted by mere wealth or rank. Yet he might by selection do something not only for the bodily constitution and frame of his offspring, but for their intellectual and moral qualities. Both sexes ought to retrain from marriage if in any marked degree inferior in body or mind ; but such hopes are Utopian and will never be even partially realised until the laws of inheritance are thoroughly known. All do good service who aid towards this end. When the principles of breeding and of inhe- ritance are better understood, we shall not hear ignorant members of our legislature rejecting with scorn a plan for ascertaining by an easy method whether or not con- sanguineous marriages are injurious to man.
The advancement of the welfare of mankind is a most intricate problem : all ought to refrain from marriage who cannot avoid abject poverty for their children ; for poverty is not only a great evil, hut tends to its own increase by leading to recklessness in marriage. On the other hand, as Mr. Gallon has remarked, if the prudent avoid marriage, whilst the reckless marry, the inferior members will tend to supplant the better members of society. Man, like every other animal, has no doubt ad- vanced to bis present high condition through a struggle for existence consequent on his rapid multiplication ; and if he is to advance still higher he must remain subject to a severe struggle. Otherwise he would soon sink into indolence, and the more highly-gifted men would not be more successful in the battle of life than the less gifted. Hence our natural rate of increase, though leading to many and obvious evils, must not he greatly diminished by any means. There should be open competition for all men ; and the most able should Dot be prevented by laws or customs from succeeding best and rearing the largest number of offspring. Im-
2 D 2
404
GENERAL SUMMARY
Part II.
T . Stl le for existence has been and even
still is, yet as far as the highest part of man’s nature is concerned there are other agencies more important. For the moral qualities are advanced, either directly or in- directly, much more through the effects of habit, the reasoning powers, instruction, religion, &c., than through natural selection ; though to this latter agency the social instincts, which afforded the basis for the development ot the moral sense, may be safely attributed.
The main conclusion arrived at in this work, namely that man is descended from some lowly-organised form, will, I regret to think, be highly distasteful to many persons. But there can hardly be a doubt that we are descended Irom barbarians. The astonishment which I felt on first seeing a party of Fuegians on a wild and broken shore will never be forgotten by me, for the reflection at once rushed into my mind — such were our ancestors. These men were absolutely naked and bedaubed with paint, their long hair was tangled, their mouths frothed with excitement, and their expression was wild, startled, and distrustful. They possessed hardly any arts, and like wild animals lived on what they could catch ; they had no govern- ment, and were merciless to every one not of their own small tribe. He who has seen a savage in his native laud will not feel much shame, if forced to acknowledge that the blood of some more humble creature flows in his veins. For my own part I would as soon be descended from that heroic little monkey, who braved his dreaded enemy in order to save the life of his keeper , or from that old baboon, who, descending from the mountains, carried away in triumph his young comrade from a crowd of astonished dogs— as from a savage who delights to torture his enemies, offers up
Chap. XXI.
AND CONCLUDING REMARKS.
405
Woody sacrifices, practises infanticide without remorse, treats his wives like slaves, knows no decency, and is haunted by the grossest superstitions.
Man may be excused for feeling some pride at having risen, though not through his own exertions, to the very summit of the organic scale ; and the fact of his having thus risen, instead of having been aboriginally placed there, may give him hopes for a still higher- destiny in the distant future, hut we are not here concerned with hopes or fears, only with the truth as far as our reason allows us to discover it, I have given the evidence to the best of my ability ; and we must acknowledge, as it seems to me, that man with all his noble qualities, with sympathy which feels for the most debased, with benevolence which extends not only to other men but to the humblest living creature, with his god-like intellect which has penetrated into the move- ments and constitution of the solar system — with all these exalted powers — Man still bears in his bodily frame the indelible stamp of his lowly origin.
ABBOTT.
ALCA.
Abbott, C., on the bottles of seals, ii. 240.
Abductor of the fifth metatarsal, presence of, in man, i. 128.
Abercrombie, Dr., on disease of the brain affecting speech, i. 58.
Abipones, marriage-customs of the, ii. 373.
Abou-Simbkl, caves of, i. 217.
Abortion, prevalence of the practice of, i. 134.
Abstraction, i. G2.
Acalles, stridulation of, i. 384.
Acanthodaci.i/lus capcnsis , sexual dif- ferences of colour in, ii. 36,
Accentor modularis, ii. 198.
Acclimatisation, difference of, in dif- ferent races of men, i. 216.
Achetidx, stridulation of the, i. 352, 353, 355 ; rudimentary stridnlating organs in female, i. 359.
Acilius rule, this, elytra of the female, i. 343.
-4com?fs, development of spurs in tlie female of ii. 162.
AuHdiidx, stridulation of the, i. 352, 356; rudimentary stridnlating or- gans in female, i. 309.
Acting, i. 232.
Admix, bright colours of. i. 322.
Admiral butterfly, i. 392.
Adoption ot the young of other ani- mals by female monkeys, i. 41.
Advancement in the organic scale, Von Baer’s definition of, i. 211.
Aeiiv, on the difference between the skulls of man and the quatlrumaua i. 190.
^Esthetic facility, not highly deve- loped in savages, i. 64.
Affection, maternal, i. 40 ; mani- festation of, by animals, i, 40 ; pa-
rental and filial, partly the result of natural selection, i. 81 ; shown by birds in confinement, for certain persons, ii. 110; mutual, of birds, ii. 108.
Africa, probably the birthplace of man, i. 199 ; South, crossed popu- lation of, i. 225; South, retention of colour by the Dutch in, i. 242 South, proportion of the sexes i® the butterflies of, i. 310; tattooing practised in, ii. 339 ; 'Northern, coiffure of natives of, ii. 340.
Agassiz, L, on conscience in dogs, >• 78 ; on the coincidence of the rac®9 of man with zoological provinces, *• 218; on the number of species man, i. 226; on the courtship oftbe land-snails, i. 324; on the bright' ness of the colours of male fish®9 during the breeding season, ii. on the frontal protuberance of th0 males of Geoj)hagu$ and CHchht, |]‘ 13, 20; on the slight sexual di#e*- ences of the South Americans, 323 ; on the tattooing of the Au111" zonian Indians, ii. 342.
Age, in relation to the transmissi°D of characters in birds, ii. 183; r;V> riation in accordance with, in birJ5' ii. 213.
Agdiuus phamiceus, ii. 116.
Ageronia feronia , noise produced hji
i. 387.
Agrion , dimorphism in, i. 363.
Agrion Mamburii , sexes of, i. 362. .
AgriONIda*;, difference in the sexes 0 ’ i. 362.
Agrotis exdamatioms, i. 369.
Ague, tertian, dog suffering i. 13.
AWiurus polytmus , young of, ii. 226*
AlNOS, hairiness of the, ii. 321.
Alca tor da , young of’ ii. 217.
ALCES.
INDEX.
ANTHIDIUM.
407
Alces palmata, ii. 259.
Alder and Hancock, MM., on the nudi-branch mollusea, i. 326.
Algen, Mr., on the st rid illation of Scolytus , i. 379.
Allen, J. A., on the relative size of the sexes of Callorhinus ursinus, ii. 2G0 ; on the mane of Otaria jubata , ii. 267 ; on the pairing of seals, ii. 279 ; on sexual differences in the colour of bats, ii. 286.
Allen, S., on the habits of JIoplo- pterus, ii. 48; on the plumes of herons, ii. 82 ; on the vernal moult of Herodias bubulcus, ii. 84. Alligator, courtship of the male, i. 272, ii. 29; roaring of the male,
i. 331.
Amadavat, pugnacity of male, ii. 49. Amadina Lathavu, display of plum- age by the male, ii. 95.
Amadina casta not is, display of plum- age by the male, ii. 95.
Amazons, butter flies of the, i. 309 ;
fishes of the, ii. 17.
America, variation in the skulls of aborigines of, i. 108 ; wide range of aborigines of, i. 218 ; lice of the natives of, i. 220 ; general beard- lessness of the natives of, ii. 322. America, North, butterflies of, i. 309 ; Indians of, women a cause of strife among the, ii. 324; Indians of, their notions of female beauty,
ii. 344, 347.
America, South, character of the na- tives of, i. 216; population of parts of, i. 225 ; [tiles of stones in, i. 233 ; extinction of the fossil horse of, i. 239 ; desert-birds of, ii. 224 ; slight sexual difference of the aborigines of, ii. 323 ; prevalence of infanticide in, ii. 361.
American languages, often highly artificial, i. 112.
Americans, wide geographical range of, i. 112; and negroes, difference of, i. 247 ; aversion of, to hair on the face, ii. 348; native, varia- bility of, i. 226.
Amrnophila , on the jaws of, i. 342. Ammotracjus tragelaphus, hairy fore- legs of, ii. 282, 285.
Amphibia, affinity of, to the ganoid
fishes, i. 204 ; vocal organs of the, ii. 331.
Amphibians, i. 213, ii. 24; breeding whilst immature, ii. 215.
Amphioxus, i. 204.
A.mpiiipODA, males sexually mature while young, ii. 215.
Amunopu HI., negro character of fea- tures of, i. 217.
Anal appendages of insects, i. 342.
ANALOGOUS variation in the plumage of birds, ii. 74.
Anas , ii.' 180.
Anas acuta , male plumage of, ii. 84.
Anas boschas, male plumage of, ii. 84.
Anas histr ionica, ii. 214.
Anastomus oscitans, sexes and young of, ii. 217 ; white nuptial plumage of, ii. 228.
AN ATI LEE, voices of, ii. 60.
Anax junius , difference in the sexes of, i. 362.
Anglo-Saxons, estimation of the beard among the, ii. 349.
Animals, cruelty of savages to, i. 94; domesticated, more fertile than wild, i. 132; characters common to man and, i. 185 ; domestic, change of breeds of, ii. 369.
Annelida, i. 327.
Annulosa, i. 327.
Anolis cristatellus , male, crest of, ii. 32 ; pugnacity of the male, ii. 32 ; throat-pouch of, ii. 33,
Anobium tessellalum , sounds produced by, i. 384,
Ansar canadensis, ii. 116,
Anser cyynoides , ii. 114 ; knob at the base of the beak of, ii. 129.
Anser hy perborates, whiteness of, ii. 228.
Antelope, prong-horned, horns ot,
i. 289.
Antelopes, generally polygamous, i. 267 ; horns of, i. 289, ii. 245 ; ca- nine teeth of some male, ii. 241 ; use of liorus of, ii. 251 ; dorsal crests in. ii. 282 ; dewlaps ot, ii. 284 ; winter change of two species of, ii. 299; peculiar markings of,
ii. 299.
Antennae, furnished with cushions in the male of Penthe , i. 343.
Anthidium manicatum , large male of, i. 347.
408
AXTIIOCIIAEIS.
INDEX.
ARGUS.
Anthocharis cardamines, i. 388, 393 394; sexual difference of colour in’ i. 409.
Anthocharis gemtia, i. 393. Anthocharis sara, i. 393.
Anthophore, a cervorttiu, large male of
i. 347. ’
Anthophora retusa, difference of the
sexes in, i. 366.
Anthus, moulting of, ii. 83. AXTHROPIDJ5, i. 195.
Antigua, Dr. Nicholson’s observations on yellow fever in, i. 245.
Antics of birds, ii. 68.
Antilocapra amerkana, horns of i 289, ii. 245.
Antilope bezoartica, horned females of
ii. 246, 248 ; sexual difference in the colour of, ii. 288.
Antilope Dorcas and euchore, ii. 245. Antilope euchore, horns of, ii. 251. Antilope montana, rudimentary ca- nines in the young male of, ii. 258. Antilope niger, sing-sing, caanut, and gorgon , sexual differences in the colours of, ii. 289.
Antilope areas, horns of, i. 289.
Antilope saiga, polygamous habits of, i. 267.
Antilope strepsieeros, horns of, i. 289. Antilope subguiturosa, absence of sub- orbital pits in, ii. 280.
Antipathy, shown by birds in Con- finement, to certain persons, ii. 110. Ants, i. 186; playing together, i.39; memory in, i. 45 ■ intercommuni- cation of, by means of the antennas, i. 58 ; large size of the cerebral ganglia in, i. 145 . soidiei.. ) jaws of, i. 155; difference of the sexes in, i. 36o; recognition of each other by, after separation, i. 365. Ants, White, habits of, i. 364.
Aniiea, ii. 25.
Apatania muliebris, male unknown i. 314.
Apathus, difference of the sexes in i 366.
Apatura Iris, i. 386, 388.
Apes, anthropomorphous, i. 196 • difference of the young, from the adult, i. 13 ; building plat- forms, i. 53 ; probable speedy ex- termination of the, i. 201 ; Gratio-
lct on the evolution of, i. 230 ; semi-erect attitude of some, i. ] 42 ; mastoid processes of, i. 143; influ- ence of the jaw-muscles on the phy- siognomy of, i. 144 ; female, desti- tute of large canines, i. 156 ; imi- tative faculties of, i. 101 ; canine teeth of male, ii. 241 ; females of some, Jess hairy beneath than the males, ii. 377.
Apes, long-armed, their mode of pro- gression, i. 143.
Apis mellifica, large male of, i. 347. Apollo, Greek statues of, ii. 350. Apoplexy- in Cebus Azaric. i. 12. Approbation, influence of the love of, i. 86, 92, 164, 165.
Appendages, anal, of insects, i. 342. Aprosmictus scapulatus, ii. 174. Aquatic birds, frequency of white plumage in, ii. 229.
Aquila chri/saetos, ii. 105.
Akah women, elaborate and peculiar coiffure of, ii. 353.
Arabs, gashing of cheeks and temples among the, ii. 339.
Aiiachnida, i. 337.
Arakhan, artificial widening of the forehead by the natives oi; ii. 351. Arboricola, young of, ii. 190. Archcoptcryx, i. 204.
Arctiim:, coloration of the, i. 396. Ardea a$ha, rufescehs, and cseruka, chauge of colour in, ii. 231 232. Ardea castulea , breeding in immature plumage, ii. 214.
Ardea gutaris, change of pi umage in, ii. 232. 5
At t lea herodias, love-gestures of the male, ii. 68.
Ardea ludoviciana, age of mature plu- mage in, ii. 2 1 3 ; continued growth of crest and plumes in the male of, ii. 216.
Ardea nycticorax, cries of, ii. 51. Ardeola, young of, ii. 190.
Ardetta , changes of plumage in, ii, 179.
Argenteuil, i. 29.
Argus pheasant, ii. 72, 97, 181 ; dis- play of plumage by the male, ii.
91 ; ocellated spots of the, ii. 134,
141 ; gradation of characters in the, ii. 141.
ARGYLL.
INDEX.
AUSTRALIANS.
409
Argyll, Duke of, the fashioning of implements peculiar to man, i. 52 ; on the contest in man between right and wrong, i. 104 ; on the physical weakness of man, i. 156 ; on the primitive civilisation of man, i. 181 ; on the plumage of the male I Argus pheasant, ii. 91 ; on Urosticte Benjamini , ii. 151 ; on the nests of birds, ii. 167 ; on variety as an object in nature, ii. 230.
Arqynnis aglaki, colouring of the lower surface of, i. 396.
A ri cor is epitus , sexual differences in the wings of, i. 345.
Aristocracy, increased beauty of the, ii. 356.
Arms, proportions of, in soldiers and sailors, i. 116; direction of the hair on the, i. 192.
Arms and hands, free use of, indi- rectly correlated with diminution of canines, i. 144.
Arrest of development, i. 121, 122.
Arrow-iieads, stone, general resem- blance of, i. 233.
Arrows, use of, i. 232.
Arteries, variations in the course of the, i. 108.
Artery, effect of tying, upon the lateral channels, i. 116.
Arthropoda, i. 328.
Arts practised by savages, i. 234.
Ascension, coloured incrustation on the rocks of, i. 326.
Ascldia, affinity of the bracelet to, i. 205 : tadpole-like larvae of, i. 205.
Ascidians, i. 324; bright colours of some, i. 322.
Asiatic and African species of, ii. 306.
Anintcs twniopus , ii. 306.
Ass, colour- variations of the, ii. 305.
Atrles, effects of brandy on an, i. 12 ; absence of the thumb in, i. 140.
Atcles bee Iz chut it, ears of, i. 23.
Atcics marginntus, colour of the ruff of, ii. 291 ; hair on the head of, ii. 109 ; on the recognition of a dog by a turkey, ii. 110 ; on the selec- tion of a mate by female birds, ii. 307.
^tcuchus, stridulation of, i. 384.
Ateuchus cicatricosus, habits of, i. 376
Athalia , proportions of the sexes in, i. 314.
Attention, manifestations of, in ani- mals, i. 44.
Audouin, V., on a hymenopterous parasite with a sedentary male, i. 273.
Auduron, J. .1, on the pugnacity of male birds, ii. 43, 48; on Tetrao cupido , ii. 50; on Ardea nycticorax , ii. 51 ; on Stnrnetla ludovAciuna , ii. 51 ; on the vocal organs of Tetrao cupido , ii. 56 ; on the drumming of the male Tetrao umbdlns, ii. 61 ; on sounds produced by the nightjar, ii. 63 ; on Ardea herodins and Cath- artes jot a, ii. 68; on the spring change of colour in some finches, ii. 86; on Mimus polyglottus , ii. 116; on the turkey, ii. 119, 121; on variation in the male scarlet tanager, ii. 120; on the habits of Pyranga &stiva, ii. 107 ; on local differences in the nests of the same species of birds, ii. 171 ; on the habits of woodpeckers, ii. 175; on Bomby cilia carolinenm, ii. 180 ; on young females of Tanngra sestiva acquiring male characters, ii. 180; on the immature plumage of thrushes, ii. 185 ; on the immature plumage of birds, ii. 186 et seg. ; on birds breeding in immature plumage, ii. 214; on the growth of the crest and plumes in the male Ardea ludoviciana , ii. 216 ; on the change of colour in some spe- cies oi Ardea, ii. 231 ; on the specu- lum of Mergus cucullatus , ii. 291 ; on the musk-rat, ii. 298.
Audtjijon and Bachman, MM., on squirrels fighting, ii. 239 ; on the Canadian lynx, ii. 267.
Austen, N. L., on Anolti cnstatellus , ii. 32, 33.
Australia, half-castes killed by the natives of, i. 220 ; lice of the na- tives of, i. 220 ; not the birthplace of man, i. 199; prevalence of fe- male infanticide in, ii. 364.
Australia, South, variation in the skulls of aborigines of, i. 108.
Australians, colour of newborn
410
AXIS.
INDEX.
BARRINGTON.
children of, ii. 318 ; relative height of the sexes of, ii. 320 ; women a cause of war among the, ii. 323.
Axis deer, sexual difference in the colour of the, ii. 290.
A v maras, measurements of the, i. 119; no grey hair among the, ii. 320 ; hairlessness of the face in the, ii. 322 ; long hair of the, ii. 348.
Azara, on the proportion of men and women among the Guaranys, i. 302 ; on Palamedun cornuta, ii. 48 ; on the beards of the Guaranvs, ii. 322 ; on strife for women among the Gu- anas, ii. 324; on infanticide, ii. 344, 304; on the eradication of the eye- brows and eyelashes by the Indians of Paraguay, ii. 348 ; on polyandry among the Guanas, Ii. 366 ; celibacy unknown among the savages of South America, ii. 367 ; ou the freedom of divorce among the Charruas, ii. 372.
B.
Babbage, C., ou the greater propor- tion of illegitimate female births,
i. 302.
Bawrusa, tusks of the, ii. 264.
Baboon, employing a mat for shelter against the sun, i. 53 ; manifesta- tion of memory by a, i. 45 ; pro- tected from punishment by its com- panions, i. 78; rage excited in, by reading, i. 42.
Baboon, Gape, mane of the male, ii. 267 ; Hamadryas, mane of the male,
ii. 267.
Baboons, effects of intoxicating li- quors on, i. 12; ears of, i. 23; "ma- nifestation of maternal affection by, i. 41 ; using stones and sticks as weapons, i. 51 ; co-operation of, i.
' 5; silence of, on plundering expe- ditions, i. 79; diversity of tlie men- tal faculties in, i. 110 ;" bands of, i. 139 ; habits of, i. 141 ; variability of the tail in, i. 150; apparent polygamy of, i. 266 ; polygamous and social habits of, ii. 362.
Bachman, Dr., on the fertility of mu- lattoes, i. 221.
Baer, K. E. von, on embryonic deve- lopment, i. 14.
Bagehot, W., on the social virtues among primitive men, i. 93; on the value of obedience, i. 162; on human progress, i. 166 ; on the per- sistence of savage tribes in classical times, i. 239.
Bailly, E. M., on the fighting of stags, ii. 252 ; on the mode of fight- ing ot the Italian buffalo, ii. 250.
Bain, A., on the sense of duty, i. 71; aid springing from sympathy, i. 77 ; on the basis of sympathy, i. 82 ; on love of approbation, &c., i. 86 ; on the idea of beauty, ii. 354.
Baird, W., ou a difference in colour between the males and females of some Entoxua, i. 321.
Baker, Mr., observation on the pro- portion of the sexes in pheasant- chicks, i. 306.
Baker, Sir S., on the fondness of the Arabs for discordant music, ii. 67 ; on sexual difference in the colours of an antelope, ii. 289 ; on the ele- phant and rhinoceros attacking white or grey horses, ii. 295 ; on the disfigurements practised by the negroes, ii. 296 ; on the gashing of the cheeks and temples practised i& Arab countries, ii. 339 ; on the coiffure of the North Africans, ii* 340 ; ou the perforation of the lower lip by the women of Latooka, ii. 341; ou the distinctive charac- ters of the coiffure of central Afri- can tribes, ii, 342 ; ou the coiffure of Arab women, ii. 353.
Balz ” of the Black-cock. ii. 45, 100*
Bantam, Sebright, i. 259, 294.
Bant eng, horns of, ii. 247 ; sexual differences in the colours of the, ii* 289.
Banyat, colour of the, ii. 346.
Barbarism, primitive, of civilised nations, i. 181.
Barbs, filamentous, of the feathery in certain birds, ii. 74.
Barr, Mr., on sexual preference i*1 dogs, ii. 272.
Barrington, Dames, on the language of birds, i. 55 ; on the clucking the hen, ii. 51; on the object oi
BARROW.
INDEX.
BECIISTEIN.
411
the song of birds, ii. 52 ; on the singing of female birds, ii. 54 ; on , birds acquiring the songs of other birds, ii. 55; on the muscles of the larynx in song-birds, ii. 55 ; on the want of the power of song by female birds, ii. 163.
Barrow, on the widow-bird, ii. 98. Bartlett, A. D., on the tragopan, i. 270 ; on the development of the spurs in Orassoptihn auritum , i. 290 ; on the fighting of the males of JPlectropterus gtxmbensis , ii. 4G; on the knot, ii. 82 ; on display in male birds, ii. 87 ; on the display ' of plumage by the male Polyplcc- tron , ii. 89 ; on Crossoptilon auri - turn and Phasiamts WallicMi , ii. 93; on the habits of Lophnphorus , ii. 121 ; on the colour of the mouth in Buceros bkornis, ii. 129 ; on the incubation of the cassowary, ii. 204 ; on the Cape Buffalo, ii. 250 ; on the use of the horns of ante- lopes, ii. 251 ; on the fighting of male wart-hogs, ii. 266 ; on Ammo- tragus tragelaphus , ii. 282 ; on the colours of Cercopithecus cephus , ii. 291 ; on the colours of the faces of monkeys, ii. 310 ; on the naked surfaces of monkeys, ii. 377. Bartram, on the courtship of the male alligator, ii. 29.
Basque language, highly artificial, i. 61.
Bate, C. S., on the superior activity of male Crustacea, i. 272; on the proportions of the sexes in crabs, i. 315 ; on the chela? of Crustacea, i. 330; on the relative size of the sexes in Crustacea, i. 332; on the colours of Crustacea, i. 835.
Bates, H. W., on variation in the form of the head of Amazonian Indians, i. Ill; on the proportion of the sexes among Amazonian but- terflies, i. 309; on sexual differ- ences in the wings of butterflies, i. 345 ; on the field-cricket, i. 353 ; on Pyrodca piilvherrimus7 i. 367 ; on the horns of Lamellicorn beetles, i. 370, 371 ; on the colours of Epi - calisc, &c., i. 388 ; on the colora- tion of tropical butterflies, i. 391 ;
on the variability of Papilio Pesos- tris and Childrens, i. 402 ; on male and female butterflies inhabiting different stations, i. 403 ; on mi- mickry, i. 411 ; on the caterpillar of a Sphinx, i. 416 ; on the vocal organs of the umbrella-bird, ii. 58 ; on the toucans, ii. 227 ; on Brachy- urus calms, ii. 309.
Batokas, knocking out two upper in- cisal’s, ii. 340.
Batraciiia, ii. 25 ; eagerness of male, i. 272.
Bats, sexual differences in the colour of, ii. 286.
Battle, law of, i. 182 ; among beetles,
i. 375 ; among birds, ii. 40 ; among mammals, ii. 239 et seq. ; in man,
ii. 323.
Beak, sexual difference in the forms of the, ii. 39 ; in the colour of the, ii. 72.
Beaks, of birds, bright colours of, ii. 227.
Beard, development of, in man, ii. 317 ; analogy of the, in man and the quadrumana, ii. 319 ; variation of the development of the, in diffe- rent races of men, ii. 321 ; estima- tion of, among bearded nations, ii. 349; probable origin of the, ii. 379.
Beards, in monkeys, i. 192; of mam- mals, ii. 282,
Beautiful, taste for the, in birds, ii. 108 ; in the quadrumana, ii. 296.
Beauty, sense of, in animals, i. 63; appreciation of, by birds, ii. Ill ; influence of, ii. 338, 343; varia- bility of the standard of, ii. 370.
Beavan, Lieut., on the development of the horns in Cerms Midi, i. 288.
Beaver, instinct and intelligence^ of the, i. 37, 38 ; voice of the, ii. 277 ; castoreum of the, ii. 279.
Beavers, battles of male, ii. 239.
BkchSTEIN, on female birds choosing the best singers among the males, ii. 52; on rivalry in song-birds, ii. 53 ; on the singing of female birds, ii. 54 ; on birds acquiring the songs of other birds, ii. 55 ; on pairing the canary and siskin, ii. 115 ; on
412
BEDDOE.
INDEX.
BISCIIOFF.
a subvariety of the monk pigeon, ) ii. 132 ; on spurred hens, ii. 162. Beddoe, Dr., on causes of difference in stature, i. ] 15.
Bee-eater, ii. 56.
Bees, i. 73; destruction of drones and queens by, i. 82 ; pollen-baskets and stings of, i. 1.55; female, se- condary sexual characters of, i. 254 • difference of the sexes in, i. 365. ’
Beetle, luminous larva of a, i. 345. Beetles, i. 366 ; size of the cerebral ganglia in, i. 145 ; dilatation of the tore tarsi in male, i. 343- blind, i. 367 ; stridulation of, i! >378.
Belgium, ancient inhabitants of, i 237.
Bell, Sir C., on emotional muscles in man, i, 5; ‘•snarling muscles,” i.
127 ; on the hand, i. 141.
Bell, 1., on the numerical porpor- tiou of the sexes in moles, i. 305 • on the newts, ii. 24; on the croak- ing of the frog, ii. 27 ; on the dif- ference in the coloration of the sexes in Zootom vivipara , ii. 36 ; on moles fightiug, ii. 239.
Bell-turd, sexual difference in the colour of the, ii. 79.
Bell-birds, colours of, ii. 228. Benevolence, manifested bv birds in 109. ’
Bennett, a. W., on the habits of VromoMs ir retrains, ii. 205.
Bennett, Dr., on birds of paradise, ii.
oy.
anturcticai colours of, ii.
Bernicle gander pairing with a Canada goose, ii. 114,
Bettow, E., on local differences in the nests of Italian birds, ii. 171. Bhoteas, colour of the beard in,’ if.
Mringa , disciform tail-feathers of ii.
83.
Bibio, sexual differences in the o-enus i. 349. ’
Bichat, on beauty, ii. 354.
Bile, coloured, in many animals, i 323. ’ *
Biman a, i. 190.
Birds, imitations of the songs of other
birds by, i. 44; dreaming, i. 46 language of, i. 55 ; sense of beauty in, i. 63 ; pleasure of, in incubation, i. 79; male, incubation by, i. 210; and reptiles, alliance of, i. 213; sexual differences in the beak of some, i. 255 ; migratory, arrival of the male before the female, i. 259 ; apparent relation between polyga- my and marked sexual differences in, i. 270; monogamous, becoming polygamous under domestication, i. 270; eagerness of male in pursuit of the female, i. 272; wild, nume- rical proportion of tile sexes in, i. 306 ; secondary sexual characters of, ii. 38 ; difference of size in the sexes of, ii. 43; fights of male, wit- nessed by females, ii. 49 ; display ol male, to captivate the females, ii. 50 ; close attention of, to the songs of others, ii. 52 ; acquiring the song of their foster-parents, ii. 55 ; brilliant, rarely good song- sters, ii. 56 ; love-antics and dances of, ii. 68 ; coloration of, ii. 74 et seqq. ; moulting of, ii. 80 et seqq. ; unpaired, ii. 103 ; male, singing out of season, ii. 106 ; mutual afiection of, ii. 108 ; iu confinement, distinguish persons, ii. 110 ; hybrid, production of, ii. 113; European, number of species of, ii. 124; vari- ability of, ii. 124; gradation of secondary sexual characters in, ii. 135; obscurely coloured, building concealed nests, ii. 169; young female, acquiring male characters, ii. 180 ; breeding in immature plu- mage, ii. 214; moulting of, ii. 214; aquatic, frequency of white plu- mage in, ii. 229 ; vocal courtship of, ii. 331 ; naked skin of the head and neck in, ii. 377.
Birgus latro , habits of, i. 334.
Birkueck, Mr. on the finding of new mates by Golden Eagles, ii. 105. Birthplace of man, i. 1 99.
Births, numerical proportions of the sexes in, in animals and man, i. 263, 265 ; male and female, nume- rical proportion of, in England, i.
300.
Bischoff, Prof., on the agreement
bisiiop.
INDEX.
BLYTH.
413
between the brains of man and of the Orang, i. 11; figure of the embryo of the dog, i. 15; on the convolutions of the brain in the human foetus, i. 16 ; on the differ- ence between the skulls of man and the quadrurnnna, i. 190.
Bishop, J., on the vocal organs of frogs, ii. 28 ; on the vocal organs of corvine birds, ii. 55 ; on the trachea of the Merganser, ii. 60.
Bison, American, mane of the male, ii. 267.
Bitterns, dwarf, coloration of the sexes of, ii. 179.
Biziura lobata , musky odour of the male, ii. 38 ; large size of male, i i. 43.
Blackbird, sexual differences in the, i. 268 ; proportion of the sexes in the, i. 307 ; acquisition of a song by a, ii. 55 ; colour of the beak in the sexes of the, ii. 72, 227; pairing with a thrush, ii. 113 ; colours and nidification of the, ii. 170; young of the, ii. 219; sexual difference in coloration of the, ii. 226.
Black-buck, Indian, sexual differ- ence in the colour of the, ii. 288.
Blackcap, arrival of the male, be- fore the female, i. 259 ; young of the, ii. 219.
Black-cock, polygamous, i. 269; proportion of the sexes in the, i. 606; pugnacity and love-dance of the, ii. 45 ; call of the, ii. 00 ; moulting of the, ii, 83 ; duration of the courtship of the, ii. 100; sexual difference in coloration of the, ii. 226 ; crimson eye-cere of the, ii. 227 ; and pheasant, hybrids of, ii. ns.
“Lack-grouse, characters of young, ii- 185, 194.
Elackwall, J., on the speaking of the magpie, i. 59 ; on the desertion of their young by swallows, i. 84 ; °n the superior activity of male spiders, i. 272 ; on t he proportion °f the sexes iu spiders, i. 314 ; on sexual variation of colour in spi- ders, i. 337 ; on male spiders, i. 338.
Bladder-nose Seal, hood of the, ii. 278.
Blaine, on the affections of doirs, ii. 270.
Blair, Dr., on the relative liability of Europeans to yellow fever, i. 243.
Blake, C. 0., on the jaw from La Naulette, i. 126.
Blakistox, Capt., on the American snipe, ii. 64; on the dances of Tetrao phasianettits, ii, 69.
BlasiUS, Dr., on the species of Euro- pean birds, ii. 124.
Bled ms tcuirus , hornlike processes of male, i. 374.
Bleeding, tendency to profuse, i. 292.
Blenktron, Mr., on sexual prefer- ence in horses, ii. 272.
Blennies, crest developed on the head of male, duriug the breeding season, ii. 12.
B lei, him multipundata , stridulation of, i, 379.
Bloch, on the proportions of the sexes in Fishes, i. 308.
Blood, arterial, red colour of, i. 323.
Blood-pheasant, number of spurs in, ii. 46.
Bluebreast, red-throated, sexual dif- ferences of the, ii. 195.
Blumenbach, on Man, i. Ill- 0n the large size of the nasal cavities in American aborigines, i. 119; oifthe position of man, i. 190; on the number of species of man, i. 226.
Bly i h, E., observations on Indian crows, i. 77 ; on the structure of tlie band iu species of Ifglobates , i. 140; on the ascertainment of the sex of nestling bullfinches by pull- ing out breast-feathers, ii. 24; on the pugnacity of the males of Gal - linnla cristaict , ii. 41 ; on the pre- sence of spurs iu the female Euplo- camus er* 1 1 hrophl halmiis, ii. 46 ; on the pugnacity of the amadavat, ii. 49; on the spoonbill, ii. 60; on the moulting of Anthus, ii. 83 ; on the moulting of bustards, plovers, and Gallu-s bankiva, ii. 84 ; on the Indian honey-buzzard, ii. 126 ; on sexual differences in the colour oi the eyes of hornbills, ii. 129 ; on Oriolus melanocephalus , ii. 178 ; on Palxornis javanicus, ii. 179 ; on the
414
BOAR.
INDEX.
BOWS.
genus Ardetta , ii. 179 ; on the pere- grine falcon, ii. 180 ; on young female birds acquiring male cha- racters, ii. 180; on the immature plumage of birds, ii. 185 ; on re- presentative species of birds, ii. 190; on the young of Tumicc, ii. 202 ; on anomalous young of La- nins rufus and Colt/mbus glaciaUs, ii. 211 ; on the sexes and young of the sparrows, ii. 212 ; on dimor- phism in some herons, ii. 214; on orioles breeding in immature plu- mage, ii. 214; on the sexes and young of Bnp/ins and Amstomus, ii. 217 ; on the young of the black- cap and blackbird, ii. 219 ; on the young of the stonechat, ii. 220; on the white plumage of Anasto- mus, ii. 229 ; on the horns of Anti- lope bezoartica, ii. 240 ; on the horns of Bovine animals, ii. 247 ; on the mode of fighting of Ocis cgcloceros , ii. 249 ; on the voice of the Gib- bons, ii. 276; on the crest of the male wild goat, ii. 282; on the colours of Portax picta , ii. 287 ; on the colours of Ant Hope bezo- artica , ii. 288 ; on the development of the horns in the Koodoo and Eland antelopes, i. 289 ; on the colour of the Axis deer, ii. 290; on sexual difference of colour in Hylobates hooluck , ii. 291 ; on the hog-deer, ii. 308 ; on the beard and whiskers in a moukey becoming white with age, ii. 319.
Boar, wild, polygamous in India, i. 267 ; use of the tusks by the, ii. 256 ; fighting of, ii. 263.
Boitard and Corbie, MM., on the transmission of sexual peculiarities in pigeons, i. 283; on the anti- pathy shown by some female pi- geons to certain males, ii. 118,
Bold, Mr., on the singing of a sterile hybrid canary, ii. 58.
Bombkt, on the variability of the standard of beauty in Europe, ii. 370.
Bombus , difference of the sexes in, i. 366.
Bombycid;e, coloration of, i. 394; pairing of the, i, 401,
Bomb \j cilia carolinensis, red appendages of, ii. 179.
Bombj/x cynthia, i. 346 ; proportion of the sexes in, i. 309, 313; pairing of, i. 401.
Bornhyx mori , difference of size of the male and female cocoons of, i. 346 ; pairing of, i. 401.
Bombyx Pernyi , proportion of sexes of l. 313.
Bornhyx Yamamai, i. 346 ; M. Person- nat on. i. 310 ; proportion of sexes of, i. 313.
Bonaparte, C. L., on the call-notes of the wild turkey, ii. 60.
Bond, F., on the finding of new mates by crows, ii. 104.
Bone, implements of, skill displayed in making, i. 138.
Boner, 0., on the transfer of male characters to an old female chamois, ii. 245 ; on the antlers of the red deer, ii. 252 ; on the habits of stags, ii. 259 ; on the pairing of red deer, ii. 269.
Bones, increase of, in length and thickness, when carrying a greater weight, i. 116.
Bonnet monkey, i. 192.
Boomerang, i. 183,
Borens hyemalis, scarcity of the male,
i. 314.
Bory St. Vincent, on the number of species of man, i. 226; on the colours of Labrus paw, ii. 16.
Bos gaurus, horns of, ii. 247.
Bos prhmgemns, ii. 240.
Bos sonduicus, horns of, ii. 247 > colours of, ii. 289.
Botocudos, i. 181 ; mode of life of, i* 247 ; disfigurement of the ears and lower lip of the, ii. 341.
Bouciier de Perthes, J. C. de, on the antiquity of man, i. 3.
Bourbon, proportion of the 6exes i11 a species of Papilio from, i. 310.
Bourien, on tile marriage-customs the savages of the Malay Arcbi- pelago, ii. 373.
Bovidje, dewlaps of, ii. 284.
Bower-birds, ii. 102 ; habits of the,
ii. 69 ; ornamented playing-pkices of, i. 63, ii. 112.
Bows, use of, i. 232.
BRAC HIOPOD A.
INDEX.
BROW.
415
Braciiiopoda, i. 329.
^RAchycephalic structure, possible explanation of, i. 148.
Brachyscelus, second pair of anten- nae in the male, i. 337.
Brachyura, i. 332.
terackyurus calcus, scarlet face of, ii. 309.
Brafn, of man, agreement of the, with that of lower auimals, i. 10 ; convolutions of, in the human foetus, i. 16; larger in some exist- ing mammals than in their tertiarv prototypes, i. 51 ; relation of the development of the, to the progress of language, i. 57 ; disease of the, affecting speech, i. 58 ; influence of development of mental faculties npon the size of the, i. 145 ; influ- ence of the development of, on the •spinal column and skull, i. 146; difference in the convolutions of, in different races of men, i, 216.
Brakenridge, Dr., on the influence of climate, i. 115.
&HAUBACH, Prof., on the quasi-reli- gious feeling of a dog towards his master, i. 68; on the self-restraint of dogs, i. 78.
Waiter, F., on dimorphism in Neuro- f Ami's, i. 363.
Brazil, skulls found in caves of, i. 218 ; population of, i. 225 ; com- pression of the nose by the natives of, if. 352.
■^Reak between man and the apes, i.
200.
■^hEAM, proportion of the sexes in the, i. 308.
Breeding, age of, in birds, ii. 214.
Breeding season, sexual characters making their appearance in the, in
p birds, ii. 80.
on the effects of intoxicating liquors on monkeys, i. 12; on the Recognition of women by male Cyno- -phaU , i. 13 ; 011 revenge taken by donkeys, i. 40 ; ou manifestations maternal affection by monkeys aod baboons, 1. 41 ; on the instinc- tive dread of monkeys for serpents,
*• 42 ; on a baboon using a mat for shelter from the sun, i. 53 ; on the Use of stones as missiles by baboons,
i. 51 ; on the signal-cries of mon- keys, i. 57 ; on sentinels posted by monkeys, i. 74; ou co-operation of animals, i. 75; on an eagle attack- ing a young C^.pithecus, i. 76 ; on baboons in confinement protecting one of their number from punish- ment, i. 78; on the habits of ba- boons when plundering, i. 79; on the diversity of the mental faculties of monkeys, i. 110; ou the habits of baboons, i. 141 ; on polygamy in < j'ynocephalus and Cebns, i. 266 ; on the numerical proportion of the sexes in birds, i, 306 ; on the love- dance of the Black-cock, ii. 45; on Palameden cornuta , ii. 48 ; on the habits of the Black-grouse, ii. 49 ; on sound produced by Birds of Paradise, ii. 63 ; on assemblages of grouse, ii. 101; on the finding of new mates by birds, ii. 106 ; on the fighting of wild boars, ii. 263* on the habits of Cynoccphalul hamadnjnSy ii. 362.
Brent, Mr., on the courtship of fowls, ii. 117.
Breslau, numerical proportion of male and female births in, i. 301.
Bridgman, Laura, i. 57.
BlUMSTONli butterfly, i. 395; sexual difference of colour in the i 409
British, ancient, tattooing practised by, it. 359.
Broca, Prof., on the occurrence of the supra-condyloid foramen in the human humerus, i. 28; on the capacity of Parisian skulls at diffe- i cut periods, i. 149 ; on the influence of natural selection, i. 152 ; on hybridity in ma[1, j. 220 ; on human remains from I.es Eyzies, i. 237; on the cause of the difference be- tween Europeans and Hindoos, i. 24,0.
Biiodik, Sir B., on the origin of the moral sense in man, i. 71.
BitottN, II. G., ou the copulation of insects of distinct species, i. 342.
Bronze period, men of, in Europe, i. 160.
Brown, R., sentinels of seals generally females, i. 74; on the battles of seals, ii. 240 j on the narwhal, ii.
416
BROWN.
INDEX.
BUSHMEN.
242 ; on the occasional absence of the tusks in the female walrus, ii. 242 ; on the bladder-nose seal, ii. 278 ; on the colours of the sexes in Phoca gi'CenlandiaX) ii. 287 ; on the appreciation of music by seals, ii. 333 ; on plants used as love- philters, by North American women, ii. 344.
Brown-SeQUARD, Dr., on the inheri- tance of the effects of operations by guinea pigs, ii. 380.
Bruce, on the use of the elephant’s tusks, ii. 249.
Bruleiue, P. de la, on the habits of Ateuchus cicatricosus , i. 37(3 ; on the stridulatiou of Ateuchus, i. 384.
Brunnich, on the pied ravens of the Feroe islands, ii. 12(3.
Brvant, Oapt., on the courtship of Callorkinus ursinus, ii. 2(39.
Bu'kis bison , thoracic projection of, i. 372.
Bucephalus capensis, difference of the sexes of, in colour, ii. 29.
Buceros , nidification and incubation of, ii. 169.
Buceros bicornis , sexual differences in the colouring of the casque, beak, and mouth in, ii. 129.
Buceros corrugatus, sexual difference in the beak of, ii. 72.
Buchner, L., on the origin of man, i. 4; on the want of self-conscious- ness, &c., in low savages, i. 62 ; on the use of the human foot as a prehensile organ, i. 142 ; on the mode of progression of the apes, i. 142.
Bucklaxd, F., on the numerical pro- portion of the sexes in rats, i. 305 ; on the proportion of the sexes in the trout, i. 308 ; on Chimiera mon - strosa, ii. 12.
Buckland, W., on tne complexity of crinoids, i. 61.
Buckler, W., proportion of sexes of Lepidoptera reared by, i. 313.
Buckinghamshire, numerical pro- portion of male and female births in, i. 300.
Bucorax abyssinicus , inflation of the neck-wattle of the male, during courtship, ii. 72.
Budgies Pan, i. 260.
Buffalo, Cape, ii. 250.
Buffalo, Indian, horns of the, ii* 247.
Buffalo, Italian, mode of fighting of the, ii. 250.
Buffon, on the number of species of man, i. 226.
Bugs, i. 349.
Bujst, R., on the proportion of the sexes in salmon, i. 308 ; on the pug- nacity of the male salmon, ii. 3.
Bulbul, pugnacity of the male, ii* 41 ; display of under tail-coverts by the male, ii. 96.
Bull, mode of fighting of the, ii. 250 ; curled frontal hair of the, ii. 282.
Bullfinch, sexual differences in the,
i. 269; piping, ii. 52; female, sing- ing of the, ii. 54; courtship of the,
ii. 94 ; widowed, finding a new mate, ii. 105 ; attacking a reed- bunting, ii. Ill ; nestling, sex as- certained by pulling out breast- feathers, ii. 214.
Bullfinches distinguishing persons, ii. 110; rivalry of female, ii. 121.
Bulls, two young, attacking an old* one, i. 75 ; wild, battles of, ii. 240.
Bull-trout, mate, colouring of, during the breeding season, ii. 14.
Bunting, reed, head feathers of the male, ii. 95; attacked by a bull- finch, ii. 111.
Buntings, characters of young, h* 184.
Buphus coromandus , sexes and young of, ii. 217 ; change of colour in, h* 231, 232.
Buhcii ell, Dr., on the zebra, ii. 302; on the extravagance of a Bush- woman in adorning herself, 11, 344; celibacy unknown among the savages of South Africa, ii. 367 ; on the marriage-customs of the Bush women, ii. 374. .
Burke, on the number of species ot man, i. 226.
Burmese, colour of the beard in, 1!* 319. -
Burton, Capt., on negro ideas 0 female beauty, ii. 346 ; on a u®1' versal ideal of beauty, ii. 351.
Bushmen, i. 157.
BUSH W OMAN.
INDEX.
CANINE.
417
Bushwoman, extravagant ornamenta- tion of a, ii. 344.
Bush women, hair of, i. 216 ; mar- riage-customs of, ii. 374.
Busk, Prof. G., on the occurrence of the supra-condyloid foramen in the human humerus, i. 28.
Bustard, throat- pouch of the mule, ii. 58 ; humming noise prodneed by a male, ii. 65 ; Indian, ear-tufts of a, ii. 73.
Bustards, occurrence of sexual dif- ferences and of polygamy among the, i. 269 ; love-gestures of tho male, ii. 68; double moult in, ii, 81, 83.
-biJTLER, A. G., on sexual differences in the wings of Arlcoris epitus , i. 345 ; on the colouring of the sexes in species of Thedfy i, 389 ; on the resemblance of Iphias glamippe to a leaf, i. 394 ; on the rejection of certain moths and caterpillars by lizards and frogs, i. 417.
Butterfly, noise produced by a, i. 387; Emperor, i. 386, 388; mea- dow brown, instability of the ocel- lated spots of, ii. 132.
Butterflies, proportion of the sexes in, i. 309; forelegs atrophied in some male, i. 344 ; sexual difference in the neuration of the wings of, i. 345 ; pugnacity of male, i. 386 ; protective resemblances of the lower surface of, i. 392 ; display of the wings by, i. 396 ; white, alight- ing upon bits of paper, i. 400; attracted by a dead specimen of the same species, i. 400; courtship of, h 400 ; male and female, inhabiting different stations, 1. 403,
Buxton, C., observations on macaws, i- 76 ; on an instance of benevolence in a parrot, ii. 109.
Buzzard, Indian honey-, variation in the crest of, ii. 126.
C.
Cabbage butterflies, i. 393.
Cachalot, large head of the male, ii. 242.
Cadences, musical, perception of, by animals, ii. 333.
vol. xr.
Caecum, i. 27 ; large, in the early progenitors of man, i. 206.
Cairina moschata , pugnacity of the male, ii. 43.
Gdlliamssa , chela; of, figured, i. 330.
CaUionymus lyra, characters of the male, ii. 7.
Callorhinus ursinus, relative size of the sexes of, ii. 260 ; courtship of, ii* 269.
Calotes nigrilabris, sexual difference in the colour of, ii. 36.
Cambridge, O. Pickard, on the sexes of spiders, i, 315,
Camel, canine teeth of male, ii. 241, 257.
Campbell, J., on the Indian elephant, i. 267, 268; on the proportion of male and female births in the harems of Siam, i. 303.
Cinnpylopterus hemileucurus , i. 307.
Canaries distinguishing persons, ii.
110.
Canary, polygamy of the, i. 270; change of plumage in, after moult- ing, i. 294; female, selecting the best singing male, ii. 52; sterile hybrid, singing of a, ii. 53; female, singing of the, ii. 54; selecting a greenfinch, ii. 115; and siskin, pair- ing of, ii. 115.
Caudal vertebra?, number of, in macaques and baboons, i. 150 ; basal, of monkeys, imbedded in the body, i. 151.
Canestiuni, G., on rudimentary cha- racters and the origin of man, i. 4; on rudimentary characters, i. 17 ; on the movement of the ear in man, i. 2Q; oa the variability of the vermiform appendage in man, i. 27 ; on tho abnormal division of the malar bone in man, i. 124; on ab- normal conditions of the human uterus, i. 124; on the persistence of the frontal suture iu man, i. 125 ; on the proportion ot the sexes in silk-moths, i. 309, 311.
Canine teeth in man, i. 126; dimi- nution ol', in man, i. 144; dimi- nution of, in horses, i. 144; dis- appearance of, in male ruminants, i. 144; large, iu the early pro- genitors of man, i. 206.
2 E
418
CANINES.
INDEX.
CEBITS.
Canines, and horns, inverse develop- ment ofj ii. 257.
Canoes, use of, i. 137, 234.
Canlharis , difference of colour in the sexes of a species of, i. 367. Capercailzie, proportion of the sexes in the, i. 306; pugnacity of the male, ii. 45; pairing of the, ii. 49; autumn meetings of the, ii. 54; call of the, ii. 61 ; duration of the courtship of, ii. 100 ; behaviour of the female, ii. 121; inconvenience of black colour to the female, ii. 154; sexual difference in coloration of the, ii. 226; crimson eye-cere of the male, ii. 227 ; polygamous, i. 269.
Capital, i. 169.
Capitonid^e, colours and nidification
of the, ii. 171.
Capra wgagrus, ii. 249 ; crest of the male, ii. 282; sexual difference in the colour of, ii. 289.
Capreolus Bibiricus subccaudatus , ii. 298.
Caprice, common to man and animals,
i. 65.
Caprimulgus , noise made by the males of some species of, with their wings, ii. 62.
Caprimulgus xrirginianus , pairing of,
ii. 49.
C’ARABiDiE, bright colours of, i. 367. Carbonnter, on the natural history of the pike, i. 308 ; on the relative size of the sexes in fishes, ii. 7. Oarcineutes , sexual difference of colour in, ii. 173.
Carcinus mamas, i. 331, 333.
Car dud is elegant, sexual differences of the beak in, ii. 39.
Carnivora, marine, polygamous habits of, i. 268 ; sexual differences in the colours of, ii. 286.
Carp, numerical proportion of the sexes in the, i. 308,
Carr, R., on the peewit, ii. 48. Carrier pigeon, late development of the wattle in the, i. 293.
Carrion beetles, stridulation of, i. 378.
Carus, Prof. V., on the development of the horns in merino sheep, i. 289.
Cassowary, sexes and incubation of the, ii. 204.
Castoreum, ii. 279.
Casuarius ga/mtus, ii. 204.
Cat, convoluted body in the ex- tremity of the tail of a, i. 30 ; sick, sympathy of a dog with a, i. 77. Cataract ’in Cebus Azarx , i. 12. Catarrh, liability of Cebus Azarx to,
i. IV
Oatarruine monkeys, i. 196. Caterpillars, bright colours of, i» 415,
Cathartes aura, ii. 116.
Gathartes jot a, love-gestures of the male, ii. 68.
Catlin, G., on the development of the beard among North American Indians, ii. 322; on the great length of the hair in some North American tribes, ii. 348.
Caton, J. D., on the development of the horns in Cervus v irginianus and strongyloceros, i. 288; on the pre- sence of traces of horns in the female wapiti, ii. 245; on the fighting of deer, ii. 252 ; on the crest of the male wapiti, ii. 282 ; on the colours of the Virginian deer, ii. 288 ; on sexual difference* of colour in the wapiti, ii, 289 ; of1 the spots of the Virginian deer, ii* 303.
Cats, dreaming, i. 46 ; tortoiseshell, i* 283, 285, 293 ; enticed liy valerian?
ii. 281 ; colours of, ii. 299.
Cattle, domestic, sexual difference*
of, late developed, i. 293 ; rapid increase of, in South America, 135; domestic, lighter in winter Siberia, L 282; horns of, i. 2#9? ii. 247 ; numerical proportion the sexes in, i. 305.
Cebus, maternal affection in a, i. ^ ’ gradation of species of, i, 227.
Cebus Azanc, liability of, to the sa01® diseases as man, i. 11; distin® sounds produced by, i. 53 ; eai'Jf maturity of the female, ii. 318- Cebus capueinus , polygamous, i. 26 » sexual differences of colour in, lL 290; hair on the head of, ii- 307. Cebus vellerosus , hair on the head of? ii. 307.
CECIDOMVIDjE.
INDEX.
CHERA.
419
Ceoidomyid.®, proportions of the sexes in, i. 314.
Celibacy, unknown among the savages of South Africa and South America, ii. 307.
Centipedes, i. 339.
Cephalopoda, absence of secondary- sexual characters in, i, 325. Gephalopterus ornatus, ii. 58, 59. Cephalofiterus peruiMiger, ii. 59. Corambyx heros , stridulant organ of,
i. 380.
Gemtophora aspera, nasal appendages of, ii. 34.
Gemtophora Sloddartii, nasal horn of,
ii. 34.
Gerceris, habits of, i. 384.
Gercocebus mthiops, whiskers, &e., of ii. 308.
Cercopithecus, young, seized by an eagle and rescued by the troop, i. 76; definition of species of, i. 227. Geroopithecus Cephas, sexual difference of colour in, ii. 291, 311. Gcrcopithecus ci/vmurus aud griseom- rich's, colour of thescrotum iu,ii.291. Geroopithecus Diana, sexual differences of colour in, ii. 291, 31 1, 312. Geroopithecus grisea-viridis, i. 75. -'Crcopitheeus petaurisUi, whiskers, &e., of, ii. 308.
•'ERes, of birds, bright colours of, ii. 227.
Geriomis Temminchii, swelling of the wattles of the male during court- ship, ii. 72.
^ertulus, weapons of, ii. 257.
LGrnulus umchatus , rudimentary horns of the female, ii. 245. alces , i. 288.
jtfrvus ccmpestris , odour of, ii. 279. ^rvus canadensis , traces of horns in the female, ii. 245 ; attacking a ^an, ii. 253 ; sexual difference in the colour of, ii. 289.
C),vus elaphus , battles of male, ii. 240 ; horns of, with numerous points, ii. 252.
^nus Eldi, i. 288.
^‘n'us mantc/mricuSj ii. 303. z^VUs paludosusy colours of, ii. 290. prv,us strong yloceros, i. 288.
^uus virginianus, i. 288 ; horns of,
111 course of modification, ii. 255.
Ceryle , male black-belted in some species of, ii. 173.
Cetacea, nakedness of, i. 148. Ceylon, frequent absence of beard in the natives of. ii. 321.
Chaffinch, proportion of the sexes in the, i. 306, 307 ; courtship of , the, ii. 94.
Chaffinches, ii. 53 ; new mates found by, ii. 105.
Chulcophaps indicus, characters of young, ii. 185.
Chalcosoma atlas , sexual differences of i. 368.
ChamxleoUy sexual differences in the genus, ii. 34.
Charnxleon bifurcus, ii. 34, 35. Chamoileon Owe, nil, ii. 34, 36. Chameleons, ii. 32.
Chamois, danger-signals of, i. 74 • transfer of male characters to an old female, ii, 245.
Chanmpctes wucolor, modified wino-.
feather in the inale, ii. 64.
Chap ins, Dr., on the transmission of sexual peculiarities in pigeons i. 283; on streaked Belgian pigeons,
i. 294, ii. 157. 5
Char, male, colouring of, durino- the
breeding season, ii. 14.
Characters, male, developed iu females, i. 280 • natural, artifi- cial exaggeration oi, bv man, ii. 331 ; secondary sexual, transmitted through both sexes, i. 279. Chamdrius hiaticula and plmiatis, sexes and young of ii. 216.
Chardin on the Persians, ii. 356. Charms, worn by women, ii. 344. Ciiarruas, freedom of divorce among the, ii. 372.
Chasmorhynchus , difference of colour in the sexes of, ii. 79 ; colours of.
ii. 228.
Chastity, early estimation of, i. 96. Chatterers, sexual differences in, i. 269.
Cheiroptera, absence of secondary sexual characters in, i. 268.
Chel/E of Crustacea, i. 830, 336. Ciielonia, sexual differences in, ii. 28. Chenalopex segyptiacus, wing-knobs of, ii. 46.
Cher a progne, ii. 84. 120.
2 e 2
420
CHEST.
INDEX.
COCHIN.
Chest, proportions of, in soldiers and sailors, i. 117 ; large, of the Que- chua and Aymara Indians, i. 119.
Chevrotains, canine teeth of, ii. 257.
Ghiasogmthus, strid ulation of, i. 384-.
Chiasognathus Gruntti, mandibles of, i. 377.
Children, legitimate and illegitimate, proportion of the sexes in, i. 302.
Chiloe, lice of the natives of, i. 220 ; population of, i. 225.
Chimx.ro, monstrosity bony process on the head of the male, ii. 12.
CiiiM^EROiD fishes, prehensile organs of male, ii. 1 .
Chimpanzee, ii. 323 ; ears of the, i. 21 ; representatives of the eyebrows in the, i. 25 ; platforms built by the, i. 36; cracking nuts with a stone, i. 51; hands of the, i. 139; absence of mastoid processes in the,
i. 143 ; direction of the hair on the arms of the, i. 192 ; supposed evo- lution of the, i, 230; polygamous and social habits of the, ii. 362.
China, North, idea of female beauty in, ii. 344.
China, Southern, inhabitants of, i. 246.
Chinese, use of Hint tools by the, i. 183 ; difficulty of distinguishing the races of the, i. 215; colour of the heal’d in, ii. 319 ; general beard- lessness of the, ii. 321 ; opinions of the, on the appearance of Europeans and Cingalese, ii. 345, 347 ; com-
i pi' ess ion of the feet of, ii. 352.
Chinsdrdi, his opinion of beards, ii. 341, 349. ’
Chlamydera metadata, ii. 70.
Chlocon, pedunculated eyes of the male of, i. 341.
Ghlocphaga, colorat ion of the sexes iu,
ii. 178.
Chioroccelus Tanam (figured), i. 355.
Chorda Dorsalis, i. 207.
Chough, red beak of the, ii. 227.
CiuiOMiD/E, frontal protuberance in male, ii. 13; sexual differences in colour of, ii. 20.
Chri/semys picla , long claws of the male, ii. 28.
Chrysococcyx, characters of young of,
ii. 185.
Chrysomela cerealis, bright colours of,
i. 367.
Chrysomelidje, strid ulation of, i. 379.
Cicada pntinosa, i. 351.
Cicada septendecim , i. 351.
CiCADiE, songs of the, i. 350; rudi- mentary sound-organs in females oi; i. 359.
Cicatrix of a burn, causing modifi- cation of the facial hones, i. 147.
Cichla , frontal protuberance of male,
ii. 13.
Ctmetiere du Sud, Paris, i. 28.
Cmcloramphus crural is, large size ot male, ii. 43.
C Indus aqnaticus , ii. 170.
Cingalese, Chinese opinion of the ap- pearance of the, ii. 345.
Cirripedes, complements! males of, i. 255.
Civilisation, effects of, upon natural selection, i. 170; inlluence of, i11 the competition of nations, i. 239.
Clanging of Geese, &c., ii. 51.
Claparf.de, E., on natural selection applied to man, i. 137.
Clarke, on the marriage-customs ot the Kalmucks, ii. 373.
Classification, i. 188.
Claus, G., on the sexes of Saphirin i. 336.
Cleft-palate, inherited, i. 121.
Clmacteris erythrops , sexes of, ii. 20o-
Climate, i. 115; cool, favourable ^°. human progress, i. 167 ; power °/ supporting extremes of, by man- [• 237 ; want of connexion of, wit 1 colour, i. 241.
Cloaca, existence of a, in the early progenitors of man, L 207.
Cloacal passage existing in the hu" man embryo, i. 16.
Club, origin of the, i. 234.
Clucking of fowls, ii. 51.
Ch/fhra 4r-punctata, stridulation of, h 379.
Cobra, ingenuity of a, ii. 31.
Coccus , i. 186.
Coccyx, i. 29, 80; iu the hum»“ embryo, i. 16; convoluted bodv the extremity of the, i. 30; IlD bedded in the body, i. 151.
Cochin-China, notions of beauty 0 the inhabitants of, ii. 345, 347.
COCK.
INDEX.
CORPORA.
421
Cock, game, killing a kite, ii. 44 ; blind, fed by its companions, i. 77 ; comb and wattles of the, Li. 98 ; preference shown by the, for young hens, ii. 121 ; game, transparent zone in the lmckles of a, ii, 136.
Cock of the rock, ii. 100.
Cockatoos, ii. 226, 228, 230 ; nest- ling. ii. 109 ; black, immature plu- mage of, ii. 188.
Ccelenterata, absence of secondary sexual characters in, i. 321.
Coffee, fondness of monkeys for, i. 12.
Cold, supposed effects olj i. 116; power of supporting, by man, i.
, 237.
Coleoptera, i. 366 ; stridulant or- gans of, discussed, i, 381.
Collixgwood, 0., on the pugnacity of the butterflies of Borneo, i. 386 : on butterflies being attracted by a dead specimen of the same species, i. 400.
Colombia, flattened heads of savages
^ of, ii, 340.
Colonists, success of the English as,
i. 179.
Coloration, protective, in birds, ii. 223.
Colour, supposed to be dependent on light and heat, i. 115; correlation of, with immunity from certain poisons and parasites, i. 242 ; pur- pose of, in lepidoptera, i. 399 ; re- lation of, to sexual functions, in fishes, ii. 14; difference of, in the sexes of snakes, ii. 29 ; sexual dif- ferences of, in lizards, ii. 36; in- fluence of, in the pairing of birds of different species, ii. 115; relation of, to nidification, ii. 167, 172; sexual differences o£ in mammals,
ii. 286, 294; recognition of, by quadrupeds, ii. 295; of children, in different races of man, ii. 318; of the skin in man, ii. 381.
CotODKH, admired alike by man and animals, i. 64; bright, due to sexual selection, i. 322 ; bright, among the lower animals, i. 322, 323 5 bright, protective to butterflies and moths, i. 395; bright, in male fishes, ii. 7, 13 ; transmission of, in birds, ii. 159.
COLQUHOUN, example of reasoning in a retriever, i. 48.
Colwnba passerina, young of, ii. 188. Col ambus qlaoutlis, anomalous youu<r of, ii. 211.
Com 11, development of, in fowls, i. 295.
Combs and wattles in male birds, ii.
98.
Community, preservation of varia- tions usfdui to the, by natural selection, i. 155.
Compositas, gradation of species among the, i. 227.
Comte, C., on the expression of the ideal of beauty by sculpture, ii. 380.
Con ditiONS of life, action of changed, upon man, i. 113; influence of, on plumage or birds, ii. 196.
CONDOR, eyes and comb of the, ii. 129.
Conjugations, origin of, i. 61. Conscience, i. 91, 104; absence of, in some criminals, i. 92. Constitution, difference of, in dif- ferent races of men, i. 216. Consumption, liability of Cebus Aza- rie to, i. 12; connexion between complexion and, i. 244. Convergence, i. 230.
Cooing of pigeons and doves, ii. 60. Cook, Cnpt., on the nobles of the Sandwich Islands, ii. 356.
Cope, E. it, on the dinosauria, i. 204; on the origin of genera, ii. 215.
Copkotis ceylanica, sexual differences of, ii. 32, 36.
Cuprix, i. 370.
Capris Isidis, sexual differences of, i. 3G9.
Copris lumris, stridulation of, i. 380.
Co ii Ats, bright colours of, i. 322.
Coral-snakes, ii. 31.
Cordylusj sexual difference of colour in a. species of, ii. 36.
Corfu, habits of the chaffinch in, i. 307.
Cornelius, on the proportions of the sexes in Jjucanus Cervus, i. 313.
Corpora Wolffiana, i. 207 ; agree- ment of, with the kidneys of fishes, i. 16.
422
CORRELATED.
INDEX.
CURIOSITY.
Correlated variation, i. 130. Correlation, influence of, in the production of races, i. 247.
Corse, on the inode of fighting of the elephant, ii. 257.
Corpus corona, ii. 104.
Conus graculus, red beak of, ii. 227. Corvus pica, nuptial assembly of, ii. 102.
Cori/dalis cormitus, large jaws of the male, i. 342.
Cosmetornis, ii. 181.
Cosmetornis vex Marins, elongation of wing-feathers in, ii. 73, 97.
Cotingii>.<k, sexual differences in, i, 269 ; coloration of the sexes of, ii. 177 ; resemblance of the females of distinct species of, ii. 192.
Coitus scorpius, sexual differences in, ii. 9.
Counting, origin of, i. 181; limited power of, in primeval man, i. 234.
Courage, variability of, in the same species, i. 40 ; universal high appre- ciation of, i. 95 ; importance of, i. 162; a characteristic of men, ii. 328.
Courtship, greater eagerness of males in, i. 272 ; of fishes, ii. 2 ; of birds, ii. 50, 1 00.
Cow, winter change of the, ii. 299.
Crab, devil, i, 332.
Crab, shore, habits of, i. 331.
Crabro cribrarius, dilated tibia; of the male, i. 343.
Crabs, proportions of the sexes in, i.
Cranz, on the inheritance of dexte- rity in seal-catching, i. 117. Craweurd, on the number of species of man, i. 22G.
Crenilubrus mussa and C. melons, nests built by, ii. 19.
Crist, origin of, in Polish fowls, i. 284.
Crests, of birds, difference of, in the sexes, ii. 189; dorsal hairy, of mammals, ii. 282.
Cricket, field-, stridulatiou of the i.
353 ; pugnacity of male, i. 360. ’ Cricket, house-, stridulatiou of the i. 352, 354.
Crickets, sexual differences in, i. 361. CrtoceriDxE, stridulatiou of the, i.
'-!70
Crinoids, complexity of, i. 61.
Croaking of frogs, ii. 27.
Crocodiles, musky odour of, during the breeding season, ii. 20.
Crocodiua, ii. 28.
Crossbills, characters of young, ii. 184. 5
Crosses in man, i. 225.
Crossing of races, effects of the, i. 241.
Crossoptilvn aurif um, ii. 93, 166, 196 ; adornment of both sexes of, i. 290 ; sexes alike in, ii. 178.
Crotch, G. R., on the stridulatiou of beetles, i. 379, 382 ; on the stridu- hition of IfeliopatUes, i. 383 ; on the stridulatiou of Acalk.*, i. 384.
Crow Indians, long hair of the, ii- 348.
Crow, young of the, ii. 209.
Crows, ii. 226 ; vocal organs of the, ii. 55; living in triplets, ii. 106.
Crows, carrion, new mates found by» ii. 104.
Crows, Indian, feeding their blind companions, i. 77.
Cruelty of savages to animals, i. 94.
Crustacea, amphipod, males sexually mature while young, ii. 215 ; parasitic, loss of litnhs by female, i. 255 ; prehensile feet and antenn# of, i. 256; male, more active than female, i. 272 ; parthenogenesis in? i. 315; secondary sex mil character of, i. 328 ; auditory hairs of, ii. 333.
Crystal worn in the lower-lip bysome Central African women, ii. 341.
Cuckoo fowls, i. 294.
CtnaciDJE, i. 254, 349.
Cullen, Dr., on the throat-pouch the male bustard, ii. 58.
Cultivation of plants, probable ori- gin of* i. 167.
Cupplks, Mr., on the numerical p1’0' portion of the sexes in dogs, sheep* and cattle, i. 304, 305 ; on the Scotch deerhound, ii. 261 ; on sex- ual preference in dogs, ii. 271, 272*
CURCITLIONIDAC, sexual difference length of snout in some, i. 255 * hornlike processes in male, i. 374 ; musical, i. 378, 379.
Curiosity, manifestations of, by ani- mals, i. 42.
CURLEWS.
INDEX.
DEER.
423
Curlews, double moult in, ii. 80.
Cursores, comparative absence of sexual differences among the, i. 269.
Curtis, J., on the proportion of the sexes in Atkalia , i. 3 14-.
Cuvier, F., on the recognition of women by male quadrumana, i. 13.
Cuvier, G., views of. us to the position of man, i. 190; on instinct and intelligence, i. 37 ,* on the number of caudal vertebra in the mandrill, i, 150 ; on the position of the seals, i. 190; on Ilectocotyle, i. 325.
Cyanecula vuecioa, sexual differences of, ii. 195.
Cyamlcyon , sexual difference in colours of, ii. 173; immature plu- mage of, ii. 188.
Cychrus , sounds produced by, i, 382.
Cycnia meadica , sexual difference of colour in, i. 398.
C/gjius ferus, trachea of, ii. 59.
Cygnus o/or, white young of, ii, 211.
Cyllo Leda , instability of the ocellated spots of, ii. 133,
Cymnthus, variation in the genus, ii. 125.
CvxxpiDiB, proportions of the sexes in, i. 314.
Cynocephalus, difference of the young, from the adult, i. 13 ; male, recog- nition of women by, i. 13 ; polyga- mous habits of species of, i. 266.
Cynocephalus chacma , i. 41.
Cynocephalus (jelada , i. 51.
Cynocephalus hamidryas, i. 51 ; sexual difference of colour in, ii. 291.
Cynocephalus leucophus, colours of the sexes of, ii. 292.
Cynocephalus mormon, colours of the male, ii. 292, 296, 310.
Cynocephalus porcarius, mane of the male, ii. 267.
Cypridina , proportions of the sexes in,
. i. 315.
Cypruudve, proportion of the sexes
i in the, i. 308.
CypRUynLE, Indian, ii. 17.
C yprinodontid.e, sexual differences
^ in the, ii. 7, 9.
Cyprinus auratus , ii. 16.
Cyprinus phoxinus, spawning of, ii. 15. |
Cypris , relations of the sexes in,
i. 315.
Cystophora cristata , hood of, ii. 278.
D.
Dacelo , sexual difference of colour in,
ii. 174.
Dacelo Gaudichaudi , young male of, ii. 188.
Dal-ripa, a kind of ptarmigan, i. 306,
Damalis albifrons , peculiar markings of, ii. 301.
Damalis pygarga , peculiar markings of, ii. 300.
Dampness of climate, supposed influ- ence of, on the colour of the skin, i. 116, 242.
Danaidx, i. 387.
Dances of birds, ii. 68.
Dancinu, i. 232.
Daniell, Dr., his experience of resi- dence in West Africa, i. 245.
Dareur, protuberances artificially produced in, ii. 339.
Darwin, F., on the stridulation of Dennestes miirmus, i. 379.
Dasychira pudibvndo, , sexual difference of colour in, i. 398.
Davis, A. H., on the pugnacity of the male stag-beetle, i. 375.
Davis, J. B., on the capacity of the skull in various races of men, i. 146 ; on the beards of the Poly- nesians, ii. S22.
Death-rate higher in towns than in rural districts, i. 175.
Death-tick, i. 384.
De Candolle, Alph., on a case of in- herited power of moving the scalp,
i. 20.
D ECLENSiONS, origin of, i. 61.
Decoration in birds, ii. 71.
Decticus , i. 355.
Deer, spots of young, ii. 134, 303 ; horns of, ii. 243, 248 ; use of horns of, ii. 252, 263; size of* the horns of, ii. 259 ; female, pairing with one male, whilst others are fighting for her, ii. 269 ; male, attracted by the voice of the female, ii. 27 6 ; male, odour emitted by, ii. 279 ; development of the horns in, i.
424
DEER.
INDEX,
DISTRIBUTION.
~88 ; horns of a, in course of modi- fication, ii. 255.
I^eer, Axis, sexual difference in the Colour of the, ii. 290.
Deer, tallow, different coloured herds of, ii. 295.
Deer, Mantnhurian. ii. 303.
I>eer, Virginian, ii. .303; colour of the, not affected by castration, ii. 288 ; colours of, ii. *289. Deerhound, Scotch, greater sire of the male, i. 293, ii. 260.
Defensive organs of mammals, ii. 263.
De Geer, C., on a female spider de- stroying a male, i. 339.
Disk ay, Dr., on the bladder-nose seal, ii. 278.
Demerara, yellow fever in, i. 243. Ikndroeygn-1, ii. 185.
Dmdrophila frontalis, young of, ii. 220. Disnnv, H., on the lice of domestic animals, i. 219.
Dermestes murinus, stridulation of, i. 379.
Descent traced through the mother alone, ii. 359.
Deserts, protective colouring of ani- mals inhabiting, ii. 224.
Desmarest, on the absence of sub- orbital pits in Antilope subr/ttltu - ^80 ; on the whiskers of Macacus, ii. 283 ; on the colour of the opossum, ii. 286 ; on the colours Ot the sexes of Mm minutiis, ii. 286 ; on the colouring of the ocelot, ii.
1 i °n the colours of seals, ii. 287; on Antilope emma, ii. 289; on the colours of goats, ii. 290 ; on sexual difference nf colour in At,ks marginaim, ii. 291 ; on the man- drill, ii. 293; on Macctcus > 'nv,mol~ r/us, ii. 318.
Desmoulins, on the number of species oi man, i. 22b ; on the musk-deer ii. 281. ’
Desor, on the imitation of man by monkeys, i. 44.
Despise, P., on criminals destitute of conscience, i. 92.
Development, embryonic, of man i.
14, 16; correlated, ii. 130.
Devil, not believed in by the Fue- gians, i. 67.
Devil-crab, i. 332.
Devonian, fossil insect from the, i. 360.
Dewlaps, of cattle and antelopes, ii. 284.
Dtad&ma, sexual differences of colour- ing in the species of, i. .888. Thndema anomala , mimickrv by the female of, i. 413.
Diadema bolina , i. 413. Diamond-beetles, bright colours of,
i. 367.
Diastema, occurrence of, in man, i. 126.
Diasttltd^e, proportion of the sexes in, i. 315.
Diodorus, on the absence of beard in the natives of Ceylon, ii. 321. Dtryurui, racket-shaped feathers in,
ii. 73; nidifieation of, ii. 167. Dicrums umcrocrrcus, change of plu- mage in, ii. 179.
Didelphis opossum , sexual difference in the colour of, ii. 286. Differences, comparative, between different species of birds of the same sex, ii. 192.
Digits, supernumerary, more fre- quent in men than in women, i* 276; supernumerary, inheritance of, i. 285 ; supernumerary, early de- velopment of, i. 292.
Dimorphism in females of water- beetles, i. 343 ; in JS'eurothcmis and A: /non, i. 363.
Dipelints Canto ri, sexual differences of, i. 369.
Diplopotu, prehensile limbs of the male, i. 340.
flipsas cynodon, sexual difference in the colour of, ii. 29.
Diitera, i. 348.
Disease, generated by the contact of distinct peoples, i. 239.
Diseases common to man and the lower animals, i. 11 ; difference of liability to, in different races of mon, i. 216; new, effects of, upon savages, i. 238 ; sexually limited, i. 292.
Display, coloration of Lepidoptera for, i. 395; of plumage by male birds, ii. 86, 96.
Distribution, wide, of man, i. 137 j
DISUSE.
INDEX.
DUCKS.
425
geographical, as evidence of specific distinctness in man, i. 218.
Disuse, effects of, in producing rudi- mentary organs, i. 18 ; and use of parts, effects of, i. 116; of parts, influence of, on the races of men, i. 247.
Divorce, freedom of, among the Cliar- ruas, ii. 372.
Dixon, E. S., on the habits of the guinea-fowl, i. 270; on the pairing of different species of geese, ii. 114 ; on the courtship of peafowl, ii. 121.
Dobriziioffer, on the marriage-cus- toms of the Alipones, ii, 374.
Dogs, suffering from Tertian ague, i. 13 ; memory of, i. 45 ; domestic, progress o£ in moral qualities, i. 50; distinct tones uttered by, i. 54; pa- rallelism between bis affection for his master and religious feeling, i. 68; sociability of the, i. 74; sym- pathy of, with a sick cat, i. 77 ; sympathy of, with his master, i. 77 ; possible use of the hair on the fore- legs of the, i. 1 03 ; races of the, i. 229; diverging when drawing sledges over thin ice, i. 46 : dreaming, i. 46, 158 ; exercise of reasoning facul- ties by, i. 48; their possession of conscience, i. 78; numerical pro- portion of male and female births in, i. 304 ; sexual affection bet ween individuals of, ii. 270; howling at certain notes, ii. 333; rolling in carrion, ii. 281.
Dolichocephalic structure, possible cause of, i. 148.
Dolphins, nakedness of, i, 148.
Domestic animals, races of, i. 229 ; change of breeds of, ii. 369.
Domestication, influence of, in re- moving the sterility of hybrids, i. 222.
D’Orbigny, A., on the influence of dampness and dryness on the colour of the skin, i. 242 ; on the Y ura- caras, ii. 347.
Dotterel, ii. 203.
Doubledav, E., on sexual differences in the wings of butterflies, i. 345.
Doubleday, H., on the proportion of the sexes in the smaller moths,
i. 311; on the attraction of the males of Lasiocampa quercus and Saturnia carpini by the female, i. 312; on the proportion of the sexes in the Lepidoptera, i. 312; on the ticking of Anohin, n tcssellatum , i. 385 ; on the structure, of Ageronia feronia, i. 387 ; on white butter- flies alighting upon paper, i. 400.
Douglas, J. W.. on the sexual dif- ferences of the Jfemiptera , i. 349 ; on the colours of British Eomo- pient , i. 352.
Down, of birds, ii. 80.
Draco , gular appendages of, ii. 33.
Dkagonet, Gemmeous, ii. 7.
DraGjQN-fltkb, caudal appendages of male, i. 344; relative size of the sexes of, i. 347 ; diiierence in the sexes of, i. 361 ; want of pugnacity by the male, i. 364.
Drake, breeding plumage of the, ii., 84.
Dreams, i. 46 ; a possible source of the belief in spiritual agencies, i. 66.
Drtll, sexual difference of colour in the, ii. 291.
Dromams irroraius, ii. 204.
Dromoltva , Saharan species of, ii. 172.
Drongo shrike, ii. 179.
DrongoS, racket-shaped feathers in tho tails of, ii. 73, 83.
Dryness, of climate, supposed in- fluence of, on the colour of the skin, i. 242.
D'ri/opithecus, i. 199.
Duck, harlequin, ago of mature plu- mage in the, ii. 213; breeding in immature plumage, ii. 214.
Duck, long-tailed, preference of male, for certain females, ii. 122,
Duck, pintail, pairing with a wigeon,
ii. 114.
Duck, voice of the, ii. 60 ; pairing with a shield-drake, ii. 114; imma- ture plumage of the, ii. 188.
Duck, wild, sexual differences in the,
i. 268 ; speculum and male charac- ters of, i. 291 ; pairing with a pin- tail drake, ii. 115.
Ducks, dogs and cats recognised by,
ii. 110 ; wild, becoming polygamous under partial domestication, i. 270.
42 6
DUGONG.
INDEX.
ELLIOT.
Dugong, tusks of, ii. 242 ; nakedness of; i. 148.
Dujardin, on the relative size of the cerebral ganglia in insects, i. 145. Dunoan, Dr., on the fertility of early marriages, i. 174.
Dupont, M., on the occurrence of the supra-condyloid foramen in the hu- merus of man, i. 29.
Durand, J. P., on causes of varia- tion, i. 113,
Bureau de la Malle, on the songs of birds, i. 55; on the acquisition of an air by blackbirds, ii. 55.
Dutch, retention of their colour by the, in South Africa, i. 242.
Duty, sense of, i. 70.
Duvaucel, female Hylobates washing her young, i. 40.
Dyaks, pride of, in mere homicide, i. 94.
Eynastcs, large size of males of, i.
347. ’
Dynast i N't, strid illation of, i. 381. Dytiaous, dimorphism of females of, i. 343 ; grooved elytra of the fe- male, i. 343.
E.
Eagle, young Cercopithecus rescued from, by the troop, i. 75.
Eagle, white-headed, breeding in immature plumage, ii. 214.
Eagles, golden, new mates found by, u. 105. J 9
Ear, motion of the, 1. 20 ; external shell ot the, useless in man, i. 21 ; rudimentary point of the, in man,
l. 22.
Ears, piercing and ornamentation of the, ii. 341.
Echidna, i. 201.
Echini, bright colours of some i. 322. EcmnodekmaTA, absence of’ secon- dary sexual characters in, i. 321. Eckkr, figure of the human embryo, i. 15 ; on sexual differences in the pelvis in man, ii. 317 ; on the pre- sence of a sagittal crest in Austra- lians, ii. 319.
Edentata, former wide range of, in America, i. 219 ; absence of secon- dary sexual characters in, i. 268.
Edolius, racket-shaped feathers in, ii. 73.
Edwards, Mr., on the proportion of the sexes in North American species of Eapilio, i. 309.
Egerton, Sir P., on the use of the antlers of deer, ii. 252 ; on the pairing of red deer, ii. 269 ; on the bellowing of stags, ii. 275.
Eggs, hatched by male fishes, ii. 20.
Egret, Indian, sexes and young of, ii. 217.
Eorets, breeding plumage of, ii. 82 : ^ white, ii. 228. 1 55
Eur ember®, on the mane of the male Hamadryas baboon, if. 267. Ekstrom, M., on JIarelda alacialis, ii. 122.
Elachista rufocinerea, habits of male, i. 311.
Eland, development of the horns of ^ the, i. 289.
Elands, sexual differences of colour in, ii. 288.
Elaphomyia, sexual differences in, i. 349.
Elaphrus uUginosus, stridulation of, i. 379.
Elaps, ii. 31.
Elaterule, proportions of the sexes in, i. 313.
Elaters, luminous, i. 345.
Elephant, i. 200 ; nakedness of the,
i. 148 ; rate of increase of the, i. 135 ; Indian, polygamous habits of the, i. 267 ; pugnacity of the male,
ii. 240 ; tusks of, ii. 242, 243, 248, 249, 258 ; Indian, mode of fighting, of the, ii. 257 ; male, odour emitted by the, ii. 279 ; attacking white or
_ grey horses, ii. 295.
Elevation of abode, modifying in- fluence of, i. 120.
Elimination of inferior individuals,
i. 172.
Elk, ii, 249 ; winter change of the,
ii. 299.
Elk, Irish, horns of the, ii. 259. Ellice islands, beards of the natives, ii. 322, 349.
Elliot, It., on the numerical pre- portion of the sexes in young rats, i. 305 ; on the proportion of the sexes in sheep, i. 305.
ELLIOTT.
INDEX.
EURYGNATHUS.
427
Elliott, D. G., ou Pelecanus erythro - rhynchus, ii. 80.
Elliott, Sir WM on the polygamous habits of the Indian wild boar, i. 267.
Ellis, on the prevalence of infanticide in Polynesia, ii. 364.
Elphinstone, Mr., on local differ- ences of stature among the Hindoos, i. 115 ; on the difficulty of dis- tinguishing the native races of India, i. 215.
Elytra, of the females of Dytiscus , Acilius, Eydroporus, i. 343.
Emberiza , characters of young, ii. 184.
Emberiza miliaria , ii. 185.
Emberiza schamidm , ii. Ill; head- feathers of the male, ii. 95.
Embryo of man, i. 14, 15; of the dog, i. 15.
Embryos of mammals, resemblance of the, i. 32.
Emigration, i. 172.
Emotions experienced by the lower animals in common with man, i. 39 ; manifested by animals, i. 42.
Emperor moth, i. 398.
Emulation of singing -birds, ii. 53.
Emu, sexes and incubation of, ii. 204.
Endurance, estimation of, i. 95.
Energy, a characteristic of men, ii. 328.
England, numerical proportion of male and female births in, i. 300.
Engleheap.t, Mr., on the finding of new mates by starlings, ii. 106.
English, success of, as colonists, i. 179.
Engravers, short-sighted, i. 118.
Kntomostraca, i. 332.
Entozoa, difference of colour between the males and females of some, i.
^ 321.
Eocene, possible divergence of man during the, i. 200.
Eolid.e, colours of, produced by the biliary glands, i. 323.
Epcira, i. 337.
Epeira nigra , small size of the male of, i. 338.
Epiiemer.e, i. 341.
Epiiemeridje, i. 361.
Epiiemerina, proportions of the sexes in, i. 314.
Ephippiger vitium, stridulating organs of, i. 354, 358.
Epicalia , sexual differences of colour- ing in the species of, i. 388.
E/JUU8 hemionus , winter change of, ii. 298.
Brute-indy coloration of, i. 397.
Erect attitude of man, i. 141, 142.
Esc h rich T, on the development of hair in man, i. 24 ; on a lanuginous moustache in a female fcctus, i. 25 ; on the want of definition between the scalp and the forehead in some children, i. 192 ; on the arrange- ment of the hair in the human foetus, i. 193; on the hairiness of the face in the human feetus of both sexes, ii. 379, 380.
Esmeralda, difference of colour in the sexes of, i. 368.
Esox lueius, i. 308.
Esox retieulatus , ii. 14.
Esquimaux, i. 157, 167 ; their belief in the inheritance of dexterity in seal-catching, i. 117 ; mode of life of, i. 246.
Estrelda umandava, pugnacity of the male, ii. 49.
Eubagis, sexual differences of colour- ing in the species of, i. 389.
Euchrus lonqimanus, sound produced by, i. 381. 1
Eudromias morinej-lus , ii. 203.
Eulampis jugularis , colours of the female, ii. 168.
Euler, on the rate of increase in the United States, i. 131.
Eumomota superciluiris , racket-shaped feathers in the tail of, ii. 73.
Ewpetomena macroitra, colours of the female, ii. 168.
Euphema splendida, ii. 174.
Euplocamus erylhrophihahnus, posses- sion of spurs by the female, ii. 46.
Euplcea midamas, mimickrv of, by the female of Diadema anomala, i. 413.
Europe, ancient inhabitants of, i. 237.
Europeans, difference of, from Hin- doos, i. 240 ; hairiness of, probably due to reversion, ii. 378.
Eurostopodus , sexes of, ii. 206.
Eurygnathus, different proportions of the head in the sexes of, i. 344.
428
EUSTEPHANUS.
INDEX.
FEMALES.
Eustephanus , sexual differences of spe- cies of, ii. 39 ; young of, ii. 220.
Exaggeration of natural characters by man, ii. 351.
Exogamy, ii. 360, 364.
Expression, resemblances in, between man and the apes, 1. 191.
Extinction of races, causes of, i. 238.
Eye, destruction of the, i. 116 ; change of position in, i. 147 ; obliquity of, regarded as a beauty by the Chinese and Japanese, ii. 345.
Eyebrows, elevation of, i. 19; deve- lopment of long hairs in, 3. 25 ; in monkeys, i. 192; eradicated in parts of South America and Africa, ii. 340 ; eradication of, by the Indians of Paraguay, ii. 348.
Eyelids, coloured black, in part of Africa, ii. 339.
Eyelashes, eradication of, by the In- dians of Paraguay, ii. 348.
Eyes, difference in the colour of, in the sexes of birds, ii. 128; pillared, of the male of Chloeon, i. 341.
Eyton, T. C., observations on the de- velopment of the horns in the fal- low-deer, i. 288.
Eyzies, Les, human remains from, i. 237.
F.
l'ABRE, M.} on the habits of Cerceris, i. 364.
Facial bones, causes of modification of the, i. 147.
Faculties, mental, variation of, in the same species, i. 36 ; diversity of, in the same race of men, i. 109 ; inheritance of, i. 110 ; diversity of, in animals of the same species, i. 110; of birds, ii. 108.
Fakirs, Indian, tortures undergone by, i. 96.
Falco leucocephalics , ii. 214.
Falco peregrinus, ii. 104, 179.
Falco tinnunculus , ii. 109.
Falcon, peregrine, new mate found by, ii. 104.
Falconer, H., on the mode of fight- ing of the Indian elephant, ii. 257; on canines in a female deer, ii. 258 ; on Hyonioschus aquations , ii. 304.
Falkland islands, horses of, i. 236. Fallow-deer, different coloured herds of, ii. 295.
Famfn es, frequency of, among savages, i. 333.
Farr, Dr., on the structure of the uterus, i. 123 ; on the effects of pro- Higacv, i. 173 ; on the influence of marriage on mortality, i. 175. Farrar, F. W., on the origin of lan- guage, i. 56 ; on the crossing or blending of languages, i. 60 ; on the absence of the idea of God in certain races of men, i. 65; on early marriages of the poor, i. 173; on the middle ages, i. 178.
Fashions, long prevalence of, among savages, ii. 343, 352.
Faye, Prof., on the numerical pro- portion of male and female births in Norway and Russia, i. 301 ; on the greater mortality of male children at and before birth, i. 302. Feath ers, modified, producing sounds, ii. 63 ct seqg.f 163 ; elongated, in male birds, ii. 72, 97 ; racket-
shaped, ii, 73; barbless and with filamentous barbs in certain birds, ii. 74; shedding of margins of, ii. 85.
Feeding, high, probable, influence of, in the pairing of birds of different species, ii. 115.
Feet, modification of, in man, i. 141 ; thickening of the skin on the soles of the, i. 118.
Felis canadensis, throat-ruff of, ii. 267. Felis pardalis and F. mitis, sexual differences in the colouring of, ii* 287.
Female, behaviour of the, during courtship, i. 273.
Female birds, differences of, ii. 193. Females, presence of rudimentary male organs in, i. 208 ; preference of, for certain males, i. 262 ; pur- suit of, by males, i. 272 ; occurrence of secondary sexual characters in, i. 276; development of male cha- racters by, i. 280.
Females and males, comparative mortality of, while young, i. 264, 276 ; comparative numbers of, i. 261* 263.
FEMUR.
INDEX.
FOWLS.
429
Femur and tibia, proportions of, in the Ay mar a Indians, i. 119.
Ferquson, Mr,, on the courtship of fowls, ii. 118.
Fertilization, phenomena of, in plants, i. 273 ; in the lower animals, i. 274.
Fevers, immunity of Negroes and Mulattoes from, i. 243.
Fiber zibethicua, protective colouring of, ii. 298.
Fidelity of savages to one another,
i. 95 ; importance of, i. 162.
Field-slaves, difference of, from
house-slaves, i. 246.
Fijians, burying their old and sick parents alive, i. 77 ; estimation of the beard among the, ii. 349 ; ad- miration of, for a broad occiput, ii. 352.
Fiji Islands, beards of the natives, ii. 322, 349 ; marriage-customs of the,
ii. 373.
Filial affection, partly the result of natural selection, i. 81.
Filum terminale, i, 30.
Finch, racket-shaped feathers in the tail of a, ii. 73.
Finches, spring change of colour in, ii. 85 ; British, females of the, ii.
Fingers, partially coherent, in species of Hylobates , i. 140.
Finlayson, on the Cochin Chinese, ii. 345.
Fire, use of, i. 137, 183, 234.
Fischer, on the pugnacity of the male of Lethms cephahiles, i. 37 8.
Fish, proportion of the sexes in, i. 307 ; eagerness of male, i. 272.
Fishes, kidneys of, represented by Corpora Wolffiana in the human embryo, i. 18 ; male, hatching ova in their mouths, i. 210 ; receptacles for ova possessed by, i. 254 ; relative size of the sexes in, ii. 7 ; freshwater, of the tropics, ii. 17 ; protecti ve re- semblances in, ii. 18 ; nest-building, ii. 19; spawning uf, ii. 19; sounds produced by, ii. 23, 331 ; continued growth of, ii. 216.
Flexor polliois longus, similar varia- tion of, in man, i. 129.
Flint tools, i. 183.
Flints, difficulty of chipping into form, i. 138.
Florida, Quisoalus major in, i. 307.
Flounder, coloration of the, ii. 18.
Flower, W. H., on the abductor of the fifth metatarsal in apes, i. 128 ; on the position of the Seals, i. 190 ; on the throat-pouch of the male Bustard, ii. 58.
Fly-catchers, colours and nidification of, ii. 170.
FcETUS, human, woolly covering of the, i. 25 ; arrangement of the hair on, i. 193.
Food, influence of, upon stature, i. 115.
Foot, prehensile, in the early progeni- tors of man, i. 206 ; prehensile power of the, retained in some savages, i. 142.
Foramen, supra-condyloid, excep- tional occurrence of in the humerus of man, i. 28, 180 ; in the early progenitors of man, i. 206.
Forres, D., on the Aymara Indians, i. 110; on local variation of colour in the Quechuas, i. 246 ; on the hair- lessness of the Aymaras and Que- chuas, ii. 322 ; on the long hair of the Aymaras and Quechuas, ii. 320, 348.
Forel, F* on white young swans, ii.
211.
Formica nifa, size of the cerebral ganglia in, i. 145.
Iossils, absence of, connecting man with the apes, i. 201.
Fowl, occurrence of spurs in the female, i. 280 ; game, early pug- nacity of, i. 295 ; Polish, early development of cranial peculiarities of, i. 293 ; variations in plumage of, ii. 74 ; examples of correlated development in the, ii. 130; do- mestic, breeds and subbreeds of, ii. 178.
Fowls, spangled Hamburgh, i. 281, 294 ; sexual peculiarities in, trans- mitted only to the same sex, i. 283 ; loss of secondary sexual characters by male, i. 284; inheritance of changes of plumage by, i. 281 ; Polish, origin of the crest in, i. 284 ; period of inheritance of cha-
430
FOX.
INDEX.
GALTON.
racters by, i. 294 ; cuckoo- , i. 294 ; development of the comb in, i. 295 ; numerical proportion of the sexes in, i. 306 ; courtship of, ii. 117 ; mongrel, between a black Spanish cock and different hens, ii. 131 ; pencilled Hamburgh, difference of the sexes in, ii. 158 ; Spanish, sexual differences of the comb in, ii. 158 ; spurred, in both sexes, ii. 162.
Fox, W. D.f on some half-tamed wild ducks becoming polygamous, and on polygamy in the guinea- fowl and canary-bird, i. 270 ; on the proportion of the sexes in cattle, i. 305; on the pugnacity of the peacock, ii. 46 ; on a nuptial assem- bly of magpies, ii. 102; on the finding of new mates by crows, ii. 104; on partridges living in trip- lets, ii. 107 ; on the pairing of a goose with a Chinese gander, ii. il4.
FoxElS, wariness of young, in hunting districts, i. 50 ; black, i'i. 294,
France, numerical proportion of male and female births in, i. 301.
Francesco, B., on the Simian resem- blances of man, i. 4.
Fraser, C., on the different colours of the sexes in a species of Souilla . i. 335.
Fringilla caunabina , ii. 86.
F ri.u<ji.lla ciris , age of mature plumage in, ii. 213.
Fringilla cyanen , age of mature plu- mage in, ii. 213.
Fringilla leucophrys. young of, ii. 217.
Fringilla spinus , ii, 115.
Fringilla tristis, change of colour in, in spring, ii. 85 ; young of, ii. 216.
FeinOtILLI ire, resemblance of the females of distinct species of, ii. 192.
FROGS, ii. 25; mule, temporary recep- tacles for ova possessed by, i. 254 ; ready to breed before the females, i. 260; vocal organs of, ii. 28.
Frontal bone, persistence of the suture in, i. 124.
Fruits, poisonous, avoided by animals, i. 36.
Fuegians, i. 167, 181; mental capacity of the, i. 34; quasi-reli- gious sentimeuts of the, i. 67 ; power of sight in the, i. 118 ; skill of, in stone-throwing, i. 188; re- sistance of the, to their severe cli- mate, i. 156, 237 ; difference of stature among the, i. 115; mode of life of the, i. 246 ; resemblance of, in mental characters, to Europeans,
i. 232 ; aversion of, to hair on the face, ii. 848 ; said to admire European women, ii. 351.
FuLGOftiDAi, songs of the, i. 351.
Fur, whiteness of, in arctic animals, in winter, i. 282.
Fur-bearing animals, acquired sa- gacity of, i. 50.
G.
Gallicrex , sexual difference in the colour of the irides in, ii. 128.
Gallicrex cristatus , red caruncle occurring in the male during the breeding-season, ii. 80.
Galltnaceas, frequency of poly- gamous habits and of sexual dif- ferences in the, i. 269 ; love- gestures of, ii. 68 ; decomposed leathers in, ii. 74; stripes of young,
ii. 184; comparative sexual differ- ences between the species of, ii* 192, 194; plumage of, ii. 195.
Gallinaceous birds, weapons of the male, ii. 44; racket-shaped fea- thers on the heads of, ii. 73.
Gallinula chloropus. pugnacity of male, ii. 40.
Gallinula cristata , pugnacity of the male, ii. 41.
GallopcrdiXy spurs of, ii, 46; de- velopment of spurs in the female,
ii. 162.
Gallqpliasis , young of, ii. 190.
G alius bankiva , ii. 158 ; neck-hackles of, ii. 84.
Gallus Stanleyi , pugnacity of the male, ii. 44.
Galls, i. 152.
Galton, Mr., on the struggle between the social and personal impulses, i- 104 ; on hereditary genius, i. Hi 5 on the effects of natural selection
GAMMARUS.
INDEX.
GIBB.
431
on civilised nations, i. 168 ; on the sterility of sole daughters, i. 170 ; on the degree of fertility of people of genius, i. 171 ; on the early marriages of the poor, i. 173; on the ancient. Greeks, i. 177 ; on the Middle Ages, i. 178; on the pro- gress of the United States, i. 179 ; on South African notions of beauty, ii. 347.
Gammarus , use of the chela} of, i. 331.
Gammarus marinus , i, 334.
Garnets, white only when mature, ii. 228.
Ganoidei, i. 204.
Ganoid fishes, i. 212.
Gaour, horns of the, ii. 247.
Gap between man and the apes, i.
200.
Gaper, sexes and young of, ii. 217.
Gardner, on an example of ration- ality in a Gelasimus, i. 334.
Garrulus glandarius , ii. 104.
Gartner, on sterility of hybrid plants, i. 223.
Gasteropoda, i. 324 ; pulmoniterous, courtship of, i. 324.
G aster ustem, i. 271 ; nidification of, ii. 20.
Gasterosteus leiurus, ii. 2, 14, 20.
Gasterosteus tmchurus , ii. 2.
Gastrophora , wings of, brightly co- loured beneath, i. 397.
Gauchos, want of humanity among the, i. 101.
Gaudry, M., on a fossil monkey, i. 1.97.
Gama, seasonal change of plumage in, ii. 228.
Geese, clanging noise made by, ii. 51 ; pairing of different species of, ii. 114; Canada, selection of mates by, ii. 116.
Gegenbaur, C., on the number of digits in the Ichthyopterygia, i. 125; on the hermaphroditism of the remote progenitors of the ver- tebrata, i. 207.
Gelasimus, use of the enlarged chela of the male, i. 331 ; pugnacity of males of, i. 333; proportions of the sexes in a species of, i. 315 ; rational actions of a, i. 334 ; differ-
ence of colour in the sexes of a species of, i. 336.
Gemmules, sexual selection of, i. 285.
Genesis, i. 318.
Genius, ii. 328; hereditary, i. 111.
Genhis, fertility of men and women of, i. 171.
Geoffroy-Saint-Utlaire, Isid., on the recognition of women by male quadnimana, i. 13; on the occur- rence of a rudimentary tail in man, i. 29; on monstrosities, i. 113; on animal-like anomalies in the human structure, i. 125 ; on the correlation of monstrosities, i. 130 ; on the distribution of hair in man and monkeys, i. 149; on the caudal vertebrae of monkeys, i. 150 ; on correlated variability, i. 151 ; on the classification of man, i. 186 ; on the long hair on the heads of species of /Sfmnopithccus , i. 192 ; on the hair in monkeys, i. 194 ; on the development of horns in female deer, ii. 244 ; and F. Cuvier, on the mandrill, ii. 293 ; on Hvlobates, ii. 318, 320.
Geographical distribution, as evi- dence of specific distinctions in man
i. 218. ’
Geometry, brightly coloured be- neath, i. 397.
Geophagus, frontal protuberance of male, ii. 13, 20 ; eggs hatched by the male, in the mouth or bran- chial cavity, ii. 200.
Georgia, change of colour in Ger- mans settled in, i. 240.
Geotrupes, stridulation of, i. 380, 382.
Gep.be, M., on the nest-building of Crenilaims tnussa and C. melops,
ii. 19.
Geelakd, Dr., on the prevalence of infanticide, i. 94; ii. 344, 364; on the extinction of races, i. 237, 238.
Gervais, l1., on the hairiness of the gorilla, i. 149; oil the mandrill, ii. 293.
Gesture-lasguage, i. 232.
Ghost-moth, sexual difference of colour in the, i. 399, 402.
Gibb, Sir D., on differences of the voice in different races of men, ii. 330.
432
GIBBON.
INDEX.
GOULD.
Gibbon, Hoolock, nose of, i. 192.
Gibbons, voice of, ii. 276.
Giraffe, mute, except in the rutting season, ii. 274; its mode of using the horns, ii. 250.
Giraud-Teulon, on the cause of short sight, i. 118.
Glanders, communicable between man and the lower animals, i. 11.
Glands, odoriferous, in mammals, ii. 279, 281.
Glareola , double moult in, ii. 80.
Glomeris limbata , difference of colour iu the sexes of, i. 340.
Glowworm, female, apterous, i, 255 ; luminosity of the, i. 345,
Gnats, dances of, i. 349.
Gnu, sexual differences in the colour of the, ii. 289.
Goat, male, wild, falling on his horns, ii. 249 ; male, odour emitted by, ii. 279 ; male, wild, crest of the, ii. 282 ; Bcrbura, mane, dewlap, &c., of the male, ii. 284 ; Ivemas, sexual difference in the colour of the, ii. 289.
GOATS, sexual differences in the horns of, i. 283 ; horns of, i. 289, ii. 246 ; domestic, sexual differences of, late developed, i. 293 ; beards of, ii. 282; mode of fighting of, ii. 249, 250.
Goatsucker, Virginian, pairing of the, ii. 49.
Gobies, nidifi cation of, ii. 20.
God, want of the idea of, in some races of men, i. 05.
GODEON, M., on variability, i, 112; on difference of stature, i. 1 15 ; on the want of connexion between climate and the colour of the skin, i. 241 ; on the odour of the skin, i. 248 ; on the colour of infants, ii. 318.
Goldfinch, ii. 56, 85 ; proportion of the sexes in the, i. 307 ; sexual differences of the beak in the, ii. 39 ; courtship of the, ii. 95.
Goldfinch, North American, young of, ii. 216,
Gold-Fish, ii. 16.
Gomphus, proportions of the sexes in, i. 314 ; difference in the sexes of, i. 362.
Gonepteryx Ehamni , i. 393; sexual difference of colour in, i. 409.
Goodsir, Prof., on the affinity of the lancelet to the ascidians. i. 205.
Goosander, young of, ii. 189.
Goose, Antarctic, colours of the, ii. 228.
Goose, Canada, pairing with a Ber- nicle gander, ii. 114.
Goose, Chinese, knob on the beak of the, ii. 129.
Goose, Egyptian, ii. 46.
Goose, Sebastopol, plumage of, ii. 74.
Goose, Snow-, whiteness of the, ii. 228.
Goose, Spur-winged, ii. 46.
Gorilla, ii. 323 ; semi-erect attitude of the, i. 142 ; mastoid processes of the, i. 143 ; direction of the hair on the arms of the, i. 192 ; supposed evolution of the, i. 230; polygamy of the, i. 266, ii. 361, 362; voice of the, ii. 276; cranium of, ii. 318; fighting of male, ii. 324.
Gossk, P. II., on the pugnacity of the male Humming-birds, ii. 40.
Gosse, M., on the inheritance of artifi- cial modifications of the skull, ii. 380.
Gould, B. A., on variation in the length of the legs in man, i. 108 ; measurements of American soldiers, i. 114, 116; on the proportions of the body and capacity of the lungs in different races of men, b 216 ; on the inferior vitality ol mulattoes, i. 221.
Gould, J„ on the arrival of male snipes before the females, i. 260 ; on the numerical proportion of the sexes in birds, i, 306 ; on Xeomor- pha, ii. 39; on the species of stephmus, ii. 39; outlie Australian Musk-duck, ii. 39; on the relative size of the sexes in LUziura lobcttct and Ginoloramphus crurali s, ii. 43; on Lobivunellus lobatus , ii. 48 ; on the habits of Mcnuni Alberti, j1* 56 ; on the rarity of song in bril- liant birds, ii. 58; on Helasphor^8 pbttyccrcus , ii. 65 ; on the Bower-* birds, ii. 69, 102; on the ornamental plumage of the Humming-birds, h* 78; on the moulting of the ptar' migan, ii. 83; on the display of plumage by the male Humming- birds, ii. 86 ; on the shyness ol
GOUREAU.
INDEX.
GUARANYS.
433
adorned male birds, ii. 97 ; on the decoration of* the bowers of Bower- I birds, ii. 112; on the decoration of I their nests by Humming-birds, ii, 1 112; on variation in the genus I Cynanthus , ii. 125 ; ou the colour of the thighs in a male parakeet, ii. 126; on fjrosticte Betijtmini, ii. 151, 152; on the unification of the Orioles, ii. 168; on obscurely- ; coloured birds building concealed 1 nests, ii. 169 ; on Trogons and I Kingfishers, ii. 173 ; on Australian parrots, ii. 174; on Australian pigeons, ii. 175; on the moulting of the ptarmigan, ii. 181 ; on the immature plumage of birds, ii. 186 et seq. ; on the Australian species of lurnix , ii. 201 ; on the young of A>t hums jjolytnms , ii. 220 ; on the colours of the bills of Toucans, ii. 227 ; on the relative size of the sexes in the Marsupials of Australia, ii. 260 ; on the colours of the Mar- j supials, ii. 286.
Goureau, on the stridulation of Mu- tilla europxa , i. 366.
Gout, sexually transmitted, i. 292.
Graba, on the Pied Ravens of the Feroe Islands, ii. 126 ; on theBridled Guillemot., ii. 127.
Gradation of secondary sexual cha- I racters in birds, ii. 135.
Grallatores, absence of secondary sexual characters in, i. 270 ; double moult in some, ii. 81.
Grallina , nidifi cation of, ii. 169.
Grasshoppers, stridulation of the, i. i 356.
Gratiolet, Prof., on the authropo- ; morphous apes, i. 196 ; on the evo- | lution of the anthropomorphous ! apes, i. 230.
Gray, Asa, on the gradation of species : among the Composite, i. 227.
Gray, j. E., on the caudal vertebra ' of monkeys, i. 150 ; on the presence 1 of rudiments of horns in the female of Cenulus moschatus , ii. 245 ; ou the horns of goats and sheep, ii. j 246 ; on the beard of the Ibex, ii. i 283 ; on the Berbura goat, ii. 285 ; on sexual differences in the colora- tion of Piodents, ii. 286 ; on the co- j VOL. II.
lours of the Elands, ii. 288 ; on the Sing-sing antelope, ii. 289 ; on the colours of goats, ii. 290; on the Hog-deer, ii. 303.
“ Greatest happiness principle,” i 97, 98.
Greeks, ancient, i. 177.
Green, A. H., on heavers fighting, ii. 239 ; on the voice of the beaver ii. 277.
Greenfinch, selected by a female canary, ii. 115.
Greg, W. Ii., on the early marriages of the poor, i. 173 ; on the Ancient Greeks, i. 178; on the effects of natural selection on civilised nations,
i. 167.
Grenadiers, Prussian, i. 112.
Grey, Sir G., on female infanticide in Australia, ii. 364.
Greyhounds, numerical proportion of the sexes in, i. 263, 265 ; nume- rical proportion of male and female births in, i. 304.
Grouse, red, monogamous, i. 269 ; pugnacity of young male, ii. 48 • producing a sound by scraping their wings upon the ground, ii. 61; duration of courtship of. ii. 100 • colours and nidification ot; ii. 170. ’
Gritre, Dr., on the occurrence of the supra-condyloid foramen in the humerus of man, i. 28.
Grus amerionnus, age of mature plu- mage in, ii. 213 ; breeding in im- mature plumage, ii. 214.
Grus virgo, trachea of, ii. 60.
Gryllns campeslris, i. 353 ; pugnacity of male, i. 330.
On/llus domestkns, i. 354.
Orypvs, sexual differences in the beak in, ii. 39.
Guaxacoi;s, battles of, ii, 239 ; canine
^ teeth of, ii. 257.
Gijan-as, strife for women among the,
ii. 324; polyandry among the, ii. 366.
Guanche skeletons, occurrence of the supra-condyloid foramen in the humerus of, i. 29.
Guaranys, proportion of men and women among, i. 302 ; colour of newborn children of the, ii. 318 ; beards of the, ii. 322.
2 F
434
GEUNEE.
INDEX.
IIARE.
GtUENee, A., on the sexes of ITypery- thra , i. 310.
Guilding, L., on the stridulation of the Locustidx , i. 352.
Guillemot, variety of the, ii. 127.
Guinea, sheep of, with males only horned, i. 289.
Guinea-fowl, monogamous, i. 209; occasional polygamy of the, i. 270 ; markings of the, ii. 134,
GUINEA-PIGS, inheritance of the effects of operations by, ii. 380.
Gull, instance of reasoning in a, ii. 108.
Gulls, seasonal change of plumage in, ii. 228 ; white, ii. 228.
Gunther, Dr., on hermaphroditism in Serranus , i. 208; on male fishes hatching ova in their mouths, i. 210, ii. 20; on mistaking infertile female fishes for males, i. 308 ; on the prehensile organs of male Plagio- stomous fishes, ii. 2 ; on the pugna- city of the male salmon and trout, i ii. 3 ; on the relative size of the j sexes in fishes, ii. 7 ; on sexual dif- | ferences in fishes, ii. 8 et jteqq. ; on the genus Callionymus , ii. 9; on a protective resemblance in a Pipe- fish, ii. 18 ; on the genus Sole- nostoma, ii. 22 ; on Megalophrys montanci , ii. 20 ; on the coloration of frogs and toads, ii. 26 ; on sexual differences in the Ophidia, ii. 29 ; on differences of the sexes of lizards, ii. 32 et seqq.
Gypsies, uniformity of, in various parts of the world, i. 242.
H.
Habits, bad, facilitated by familiarity, i. 101 ; variability of the force of, i. 183.
Hack el, E., on the origin of man, i. 4 ; on rudimentary characters, i. 17 ; on the canine teeth in man, i. 126 ; on death caused by inflam- mation of the vermiform appendage, i. 28 ; on the steps by which man became a biped, i. 142 ; on man as
a member of the Catarrhine group, i. 199 ; on the position of the Le- inuridai, i. 202 ; on the genealogy of the Mammalia, i. 203 ; on the lancelet, i. 204; on the transparency of pelagic animals, i. 323 ; on the musical powers of women, ii. 337.
Hagen, H., and Walsh, B. D., on American neuroptcra, i. 314.
Hair, development of, in man, i. 24; character of, supposed to be deter- mined by light and heat, i. 116; tribution of, in man, i. 149, ii. 375; possibly removed for ornamental purposes, i. 149 ; arrangement and direction of, i. 192 ; of the early progenitors of man, i. 206 ; diffe- rent texture of, in distinct races,
i. 216 ; and skin, correlation of colour of, i. 248 ; development of, in mammals, ii. 281 ; management of, among different peoples, ii. 340; great length of’ iu some North American tribes, ii. 348; elonga- tion of the, on the human head,
ii, 380.
Hairiness, difference of, in the sexes in man, ii. 320; variation of, in races of men, ii. 321.
Hairs and excretory jHjres, numerical relation of, iu sheep, i. 248.
Hairv family, Siamese, ii. 378.
Hamadryas baboon, turning over stones, i. 75; mane of the male, h* 267.
Hamilton, C., on the cruelty of the Kaffirs to animals, i. 94; on the engrossment of the women by the Kaffir chiefs, ii. 369.
Hammering, difficulty of, i. 138.
Hancock, A., ou the' colours of the nudibranch mollusca, i. 326.
Hands, larger at birth, in the cliff' dren of labourers, i. 117; struc- ture of, in the quadrumana, i. ’ and arms, freedom of. indirectly correlated with diminution of ca' nines, i. 144.
Handwriting, inherited, i. 58.
Harcourt, E. Vernon, on Fringe cannabina , ii. 86.
Harelda glacialis , ii. 122.
Hare, protective colouring of t ie? ii. 298.
HARES.
INDEX.
HOFFBERG.
435
Hares, battles of male, ii. 239.
Harlan, Dr., on the difference be- tween field- and house-slaves, i. 246.
Harris, J. M., on the relation of com- plexion to climate, i. 245.
Harris, T. W., on the Katv-did locust, i. 353 ; on the stridulation of the grasshoppers, i. 357 ; on (Ecanthns nivalis, i. 361; on the colouring of Lepidoptera, i. 396 ; on the colour- ing of Saturnia to, i. 393.
Harrv-long-leos, pugnacity of male, i. 349.
Hartman, Dr., on the singing of Cicada septendeoim, i. 351.
Haughton, S., on a variation of the jtexor pollicis lunjus in mau, i. 129.
Hawks, feeding orphan nestling, ii. 107.
Hayes, Dr., on the diverging of sledge-dogs on thin ice, i. 46.
Head, altered position of, to suit the erect attitude of man, i. 143 ; hairiness of, in man, i. 149 ; pro- cesses of, in male beetles, i. 370; artificial alterations of the form of the, ii., 351.
IIearne, on strife for women among the North American Indians, ii. 324; on the North American In- dians’ notion of female beauty, ii. 344; repeated elopements of a North American woman, ii. 372.
Heart, in the human einln-yo, i. 16.
Heat, supposed eliects of, i. 116.
Heatocutyle, i. 325.
Hedge-warbler, ii. 193 ; young of the, ii. 209.
Heel, small projection of, in the Aymara Indians, i. 120.
H ix, r, M., on the development of the spurs in peacocks, i. 290.
Hf.licon-id.k, i. 387 ; mimickry of, by other butterflies, i. 411.
flcliopathes, stridulation peculiar to the male, i. 383.
tfeliotltria auncalata, young of, ii. 188, 189.
Helix pomutia , example of individual attachment in, i. 325.
Hellins, J., proportions of sexes of Lepidoptera reared by, i. 313.
Helmholtz, on the vibration of the auditory hairs of Crustacea, ii. 333.
I-Iemiptera, i. 349.
II emit reigns, beardless in both sexes, ii. 283.
Hepburn, Mr., on the autumn song of the water-ouzel, ii. 54.
Ifepialus /tumuli, sexual difference of colour iu the, i. 399, 402.
Herbs, poisonous, avoided by animals,
i. 36.
HerjiaphrODETISM of embryos, i. 207.
Herodias bu'iulcus, vernal moult of,
ii. 84.
Heron, love-gestures of a, ii. 68.
Heron, Sir K., on the habits of pea- fowl, ii. 119, 120, 152.
Herons, decomposed feathers in, ii. 74; breeding plumage of, ii.. 82, 83 ; young of the, ii. 208 ; some- times dimorphic, ii. 214; continued growth of crest and plumes in the males of some, ii. 216; change of colour in some, ii. 231.
Iletserina, difference in the sexes of, i. 362 ; proportion of the sexes in,
i. 314.
Heleroeerus, stridulation of, i. 379.
Hewitt, Mr. on a game-cook killing a kite, ii. 44 ; on the recognition of dogs and cats by ducks, ii. 110; on the pairing of a wild duck with a pintail drake, ii. 115; on the courtship of fowls, ii. 117 ; on the coupling of pheasants with com- mon hens, ii. 122,
Hindoo, his horror of breaking his caste, i. 99, 103.
Hindoos, local difference of stature among, i. 115; difference of, from Europeans, i. 240; colour of the beard in, ii. 319.
IHpparchia Janint, instability of the ooellated spots of, ii. 132.
Hipparchiae, i. 387.
Hippocampus, development of, i. 210; marsupial receptacles of the male,
ii. 21.
Hippopotamus, nakedness of, i. 148.
Hips, proportions of, in soldiers and sailors, i. 117,
Hodgson, S., on the sense of duty, i, 7i.
HoffberG, on the horns of the rein-
2 F 2
436
HOG.
INDEX.
HUNGER.
deer, ii. 244 ; on sexual prefer- ences shown by reindeer, ii. 273.
Hog, wart-, ii. 265 ; river-, ii. 266.
Hog-deer, ii. 303.
Holland, Sir H., on the effects of new diseases, i. 238.
Homologous structures, correlated variation of, i. 130.
IIomoptera, i. 350; stimulation of the, and orthoptera, discussed, i. 360.
Honduras, Quiscalus major in, i. 307.
Honey-buzzard of India, variation in the crest of, ii. 126.
Honey-suckers, moulting of the, ii. 83 ; Australian, nidification of, ii. 369.
Honour, law of, i. 99.
Hooker, Jos., on the colour of the beard in man, ii. 319.
Hoolock Gibbon, nose of, i. 192.
Hoopoe, ii. 56 ; sounds produced by the male, ii, 62.
Hoplopkerus armatus , wing-spurs of, ii. 48.
Horn bill, African, inflation of the neck-wattle of the male during courtship, ii. 72.
Hornbllls, sexual difference in the colour of the eyes in, ii. 129 ; nidi- fi cation and incubation of, ii. 169.
Horne, C., on the rejection of a brightly-coloured locust by lizards and birds, i. 361.
Horns, of deer, ii. 243, 248, 259; and canine teeth, inverse develop- ment of, ii. 257; sexual differences of, in sheep and goats, i. 283; loss of, in female merino sheep, i. 284; development of, in deer, i. 288; de- velopment of, iu antelopes, i. 289; from the head and thorax, in male beetles, i. 370.
Horse, polygamous, i. 267; canine teeth cl male, ii. 241 ; winter change of the, ii. 298; fossil, ex- tinction of the, in South America, i. 239.
Horses, dreaming, i. 46 ; rapid in- crease of, in South America, i. 135; diminution of canine teeth in, i. 144; of the Falkland Islands and Pampas, i. 236 ; numerical propor- tion of the sexes in, i. 263, 265;
lighter in winter in Siberia, i. 282; sexual preferences in, ii. 272; pair- ing preferently with those of the same colour, ii. 295 ; nnmerical proportion of male and female births in, i. 303 ; formerly striped, ii. 305.
Hottentot women, peculiarities of, i. 225.
Hottentots, lice of, i. 220; readily become musicians, ii. 334 ; notions of female beauty of the, ii. 345; compression of nose by, ii. 352.
House-slaves, difference of, from field-slaves, i. 246.
IIuber, P., on ants playing together, i. 39 ; on memory in ants, i. 45 ; on the intereommurricat.ion of ants, i. 58 ; on the recognition of each other by ants after separation, P 365.
Hue, on Chinese opinions of the ap- pearance of Europeans, ii. 345.
Human kingdom, i. 186.
Human sacrifices, i. 68.
Humanttv, unknown among some savages, i. 94 ; deficiency of, among savages, i. 101.
Humboldt, A. von, on the rationality of mules, i. 48; on a parrot pre- serving the language of a lost tribe,^ i. 236; on the cosmetic arts ot savages, ii. 339, 340; on the ex- aggeration of natural characters by man, ii. 351 ; on the red painting of American Indians, ii. 352.
Hume, L>., oh sympathetic feelings, P 85.
Humming-bird, racket-shaped fa- thers in the tail of a, ii. 73; dis- play of plumage by the male, ii. 80*
Humm tng -birds, ornament their nests,
i. 63, ii. 112; polygamous, i. 26^5 proportion of the sexes in, i. 307,
ii. 221 ; sexual differences in. ii- 40, 151 ; pugnacity of male, ii. 40 > modified primaries of male, ii- coloration of the sexes of, ii- young of, ii. 220; nidification of the, ii. 168; colours of female, Jl* 168. f
Humphreys, H. N., on the habits ot the Stickle-back, i. 271, ii. 2.
Hunger, instinct of, i. 89.
HUNS.
INDEX.
IMITATION.
497
Huns, ancient, flattening of the nose by the, ii. 352.
Hunter, J., on the number of species of man, i. 226 ; on secondary sexual characters, i. 253 ; on the general behaviour of female animals during courtship, i. 273; ou the muscles of the larynx in song-birds, ii. 55 ; on the curled frontal hair of the Bull, ii. 282 ; on the rejection of an ass by a female zebra, ii. 295.
Hunter, \V. \V., on the recent rapid increase of the Sari tali, i. 133 ; ou the Santali, i. 24-1.
Hussey, Mr., on a partridge distin- guishing persons, ii. 110.
Hutchinson, Col., example of reason- ing in a retriever, i. 48.
Hutton, Capt., on the male wild goat falling on his horns, ii. 249.
Huxley, T. H., on the structural agreement of man with the apes, i. 3; on the agreement of the brain in man with that of lower animals, i. 10 ; on the adult age of the Orang, i. 18 ; on the embryonic development of man, i. 14 ; on the origin of man, i. 4, 17 ; on variation in the skulls of the natives of Aus- tralia, i. 108 ; on the abductor of the fifth metatarsal in apes, i. 128 ; on the position of man, i. 191 ; on the sub-orders of primates, i. 195 ; on the LemurkUc, i. 202; on the Dinosauria, i. 204; on the amphibian affinities of the Ichthyosaurians, i. 204; on variability of the skull in certain races of man, i. 220 ; ou the races of mao, i. 229.
Hybrid birds, production of, ii. 113.
Hydrophobia communicable between man and the lower animals, i. 11.
Ilydj'oporus, dimorphism of females of, i. 343.
Hyelapkus purdnus, ii. 303.
Hygrogonu v, ii. 21.
Hyla, singing species of, ii. 27.
Hylobates, maternal affection in a, i. 40; absence of the thumb in, i, 140; upright progression of some species of, i. 143 ; direction of the hair on the arms of species of, i. 192 ; females of, less hairy below than males, ii. 320.
Hylobates agilis , i. 140 ; hair on the arms of, i. 193 ; musical voice of the, ii. 277 ; superciliary ridge of, ii. 318; voice of, ii. 332.
Hylobates hoolock , sexual difference of colour in, ii. 291.
Hylobates la/', i. 140 ; hair on the arms of, i. 193.
Hylobates huciscas, i. 140.
Hylobates syndactylus , i. 140 ; laryn- geal sac of, ii. 276.
Hymenoptera, i. 364 ; large size of the cerebral ganglia in, i. 145 ; classification of, i. 188; sexual dif- ferences in the wings of, i. 345 ; aculeate, relative size of the sexes of, i. 347.
Hymenopterqn, parasitic, with a sedentary male, i. 272.
Hyo/nosc/ms aqiiaticus, ii. 304.
Hyper yt/ira, proportion of the sexes in, i. 310.
Ilypogt/mnci dispar , sexual difference of colour in, i. 398.
IJypopyra , coloration of, i, 397.
I.
Ibex, male, falling ou his horns, ii. 249 ; beard of the, ii. 283.
Ibis, scarlet, young of the, ii. 208; white, change of colour of naked skin in, during the breeding season, ii. 80.
Ibis tantalus , age of mature plumage in, ii. 213 ; breeding in immature plumage, ii. 214, 215.
Ibises, decomposed feathers in, ii. 74; white, ii. 228, and black, ii. 230.
Ichneumonida^, difference of the sexes in, i. 365.
Johtiiyo pterygia, i. 125. Ichthyosaurians, i. 204.
Ideas, general, i. 62.
Idiots, microcephalous, imitative faculties of, i. 57 ; microcephalous, their characters and habits, i. 121.
Iguana tubenmlata, ii. 32.
Iguanas, ii. 82.
Illegitimate and legitimate children, proportion of the sexes in, i. 302.
Imagination, existence of, in animals, i. 45.
Imitation, i. 39 ; of man by monkeys,
438
IMMATURE.
INDEX.
JACQUINOT.
i. 44 ; tendency to, in monkeys, microcephalous idiots and savages, i. 56 ; influence of, i. 161. Immature plumage of birds, ii. 183, 187.
Implacentata, i. 202.
Implements, employed by monkeys, i. 51 ; fashioning of, peculiar to man, i. 52.
Impregnation, period of, influence of, upon sex, i. 303.
Improvement, progressive, man alone supposed to be capable of i. 49. Incisor teeth, knocked out or filed by some savages, ii. 340.
Increase, rate of, i. 131 ; necessity of checks in, i. 135.
Indecency, hatred of, a modern virtue, i. 96.
Indta, difficulty of distinguishing the native races of, i. 215; Cyprinidae of, ii. 17 ; colour of the beard in races of men of, ii. 319.
Indian, North American, honoured for scalping a man of another tribe, i. 93.
Individuality, i. 62.
Individuation, i. 318.
Indoj/icus carlotta , colours of the sexes of, ii. 175.
Infanticide, prevalence of, i. 94, 134; supposed cause of, ii. 344; prevalence and causes of, ii. 363 et seq.
Inferiority, supposed physical, of man, i. 156.
Inflammation of the bowels, occur- rence of, in Ccbus Azarai, i. 12. Inheritance, i. 110; of effects of use of vocal and ineniitl organs, i. 58 ; of moral tendencies, i. 102, 104* of long and short sight, i. 118 ; laws of, i. 279; sexual, i. 285; sexually limited, ii. 154.
Inquisition, influence of the, i. 179. Insanity, hereditary, i. 111.
Insect, fossil, from the Devonian, i. 360.
Inskctivora, ii. 286 ; absence of secondary sexual characters in, i. 268.
Insects, relative size of the cerebral ganglia in, i. 145 ; male, appearance of, before the females, i. 260 ; pur-
suit of female, by the males, i. 272 ; period of development of sexual characters in, i. 291 ; secon- dary sexual characters of, i. 341 ; stridulation of ii. 331.
iNSESSORKvS, vocal organs of, ii. 55.
Instep, depth of, in soldiers and sailors, i. 117.
Instinct and intelligence, i. 37.
Instinct, migratory, vanquishing the maternal, i. 83, 90.
Instinctive actions, the result of in- heritance, 1. 80.
Instinctive impulses, difference of the force of, i. 87, 89 ; and moral impulses, alliance of, i. 88.
Instincts, i. 36; complex origin of, through natural selection, i. 38 ; possible origin of some, i. 38; ac- quired, of domestic animals, i. 79 ; variability of the force of, i. 83; difference of force between the social and other, i. 89, 104 ; utilised for new purposes, ii. 335.
Instrumental music of birds, ii. 61,
66.
Intellect, influence of, in natural selection in civilised society, i. 171.
Intellectual faculties, their influ- ence on natural selection in man. i* 158; probably perfected through natural selection, i. 160.
Intelligence, Mr. II. Spencer on the dawn of, i. 37.
Intemperance, no reproach among
savages, i. 96 ; its destructiveness,
i. 172.
Intoxication in monkeys, i. 12.
fp/ms (jlnuoippe, i. 394.
Iris, sexual difference in the colour of the, In birds, ii. 72, 128.
Isctqo-pubic muscle, i. 127.
Ithaginis emeritus , number of spui's in, ii. 46.
lulus , tarsal suckers of the males ox, i. 340.
J.
Jackals learning to bark from dogs> i* 44.
Jack-snipe, coloration of the, ii. 226.
Jacquinot, on the number of species of man, i. 226.
JAEGER.
INDEX,
JUPITER.
439
Jaeger, Dr, on the difficulty of ap- proaching herds of wild animals, i. 74 ; on the increase of length in bones, i. 116; on the deposition of a male Silver-pheasant on account of spoiled plumage, ii. 120.
Jaguars, black, ii. 294.
Janson, E. W,, ou the proportions of the sexes in Tomicus villosus , i. 314 ; on stridulant beetles, i. 379.
Japan, encouragement of licentious- ness in, i. 134.
Japanese, general beardlessness of the, ii. 321; aversion of the, to whiskers, ii. 349.
Jardine, Sir W., on the Argus phea- sant, ii. 72, 97.
Jarrold, Dr., on modifications of the skull induced by unnatural posi- tion, i. 147.
Javanese, relative height of the sexes of, ii. 320 ; notions of female beauty, ii. 347.
Jaw, influence of the muscles of the, upon the physiognomy of the apes, i. 144.
Jaws, smaller in the same ratio with the extremities, i. 117 ; influence of food upon the size of, i. 118; diminution of, in man, i. 144 ; in man, reduced by correlation, ii. 325. Jay, young of the, ii. 209 ; Canada, young of the, ii. 209.
Jays, new mates found by, ii. 104;
distinguishing persons, ii. 110. Jeffreys, J. Gwyn, on the form of the shell in the sexes of the Gastero- poda, i. 324; on the influence of light upon the colours of shells, i. 326.
Jelly-fish, bright colours of some,
i. 322.
Jenner, Dr., on the voice of the rook,
ii. 61 ; on the finding of new mates
by magpies, ii. 103 ; on retardation of the generative organs in birds, ii, 107. .
Jenyns, L., on the desertion of their young by swallows, i. 84 ; on male birds singing after the proper sea- son, ii. 107.
Jerdon, Dr., on birds dreaming, 46 ; on the pugnacity of the male bul- bul, ii. 41 ; on the pugnacity of the
male Ortygornis gularis , ii. 44 ; on the spurs of Galloperdix , ii. 46 ; on the habits of Lobimnellus , ii. 48; on the spoonbill, ii. 60; on the drumming of the Kalij-pheasant, ii. 63; on Indian bustards, ii. 65 ; on Otis bengalensis , ii. 69; ou the ear- tufts of Sypheobides auritus , ii. 73; on the double moults of certain birds, ii. 82; on the moulting of the honey-suckers, ii. 83 ; on the moulting of bustards, plovers, anil drongos, ii. 84; on display in male birds, ii. 86 ; on the spring change of colour in some finches, ii. 86 ; on the diplay of the under tail- coverts by the male bulbul, ii. 96 ; on the Indian honey-buzzard, ii. 126; on sexual differences in the colour of the eyes of hornbills, ii. 129 ; on the markings of the Tra- gopan pheasant, ii. 134; on the ni- dificat.ion of the Orioles, ii. 168; on the nidification of the hornbills, ii. 169; on the Sultan yellow-tit, ii. 174; ou Palmornis javanicus , ii. 180 ; on the immature plumage of birds, ii. 186 ct scq. ; on represen- tative species of birds, ii. 190; on the habits of Tumix, ii. 202; on the continued increase of beauty of the peacock, ii. 216; on coloration in the genus Palmornis , ii. 231. Jevons, W. S., on the migrations of man, i. 135.
Jews, ancient, use of flint tools by the, i. 183; uniformity of, in various parts of the world, i. 242 ; numerical proportion of male and female births among the, i. 301 ; ancient, tattooing practised by, ii. 339.
Johnstone, Lieut., on the Indian elephant, i. 268.
Jollofs, fine appearance of the, ii. 357.
Jones, Albert, proportion of sexes of Lepidoptera, reared by, i. 313. Juan Fernandez, humming-birds of, ii. 221. p
Junonia , sexual differences of colour- ing in species of, i. 389.
Jupiter, Greek statues of, ii. 350.
440
KAFFIR.
INDEX.
LACERTILIA.
K.
Kaffir skull, occurrence of the dia- stema in a, i. 1 26.
Kaffirs, their cruelty to animals, i. 94 ; lice ot the, i, 220 ; colour of the, ii. 347 ; engrossment of the handsomest women by the chiefs ol the, ii. 369 ; marriage-customs of the, ii, 373.
Kalij-piieasant, drumming of the male, ii. 62; voting of, ii. 190.
K ultima , resemblance of, to a withered leaf, i. 392.
Kalmucks, aversion of, to hairs on the face, ii. 349 ; marriage-customs of the, ii. 373.
Kangaroo, great red, sexual dif-
^ ference in the colour of, ii. 286,
Kant, Imm., on duty, i. 70 ; on self- restraint, i. 86; on the number of species of man, i. 226,
Katy-did, stridulntion of the, i. 352.
Keller, Dr., on the difficulty of fashioning stone implements, i. 138.
Kestrels, new mates found bv, ii. 104.
Kidney, i. 116.
King, W. R., on the vocal organs of Jetrao cupido , ii. 56 ; on the drum- ming of grouse, ii. 63 ; on the rein- deer, ii. 244 ; on the attraction of male deer by the voice of the female, ii. 276.
King and I1 itzroy, on the marringe-
^ customs of theFuegians, ii. 374.
King-crows, nidification. of, ii. 167.
Kingfisher, ii. 56 ; racket -shaped
feathers in the tail of a, ii. 73.
Kingfishers, colours and nidification ot the, ii. 171, 173, 176 ; immature plumage of the, ii. 188, 190; young of the, ii. 209.
King Lory, ii, 174; immature plu- mage of the, ii. 188.
Kingsley, C., on the sounds produced by Umbrina , ii. 23.
Kirby and Spence, on the courtship of insects, i. 272; on sexual differ- ences in the length of the snout in curculionidte, i. 255 ; on the elytra of Dytisctis , i. 343 ; on peculiarities |
in the legs of male insects, i. 344; on the relative size of the sexes in in- sects, i. 345; on the luminosity of iusects, i. 845; on the FulgorkLe, i. 351 ; on the habits of I entities, i. 364; on difference of colour in the sexes ol beetles, i. 367 ; on the horns of the male lamellicorn beetles, i. vD 1 ; on hornlike processes in male curculionidai, i. 374; ou the pugna- , city of the male stag-beetle, i. 375. Kite, killed by a game-cock, ii. 44. Knot, retention of winter plumage by the, ii. 82.
Knox, Ii., on the semilunar fold, i. 23 ; ou the occurrence of the supra- condyloid foramen in the humerus of man, i. 28; on the features of the young Memnon, i. 217.
Koala, length of the coecum in, i. 27. Kolreutkr, on the sterility of hybrid plants, i. 223.
7i obits cltipsiprymnus , proportion of the sexes in, i. 305,
Koodoo, development of the horns of the, i. 289 ; markings of the, ii.
_ 300.
KoPPEN, F. T., on the migratory lo- cust, i. 352.
Kordofan, protuberances artificially produced in, ii. 339.
Kowalevsky, A., on the affinity of the Ascidia to the Vertebrata, i. 205.
Kowalevsky, W., on the pugnacity ot the male Capercailzie, ii. 45; on ^ the pairing of the Capercailzie, ii. 49. Krause, on a convoluted body at the extremity of the tail in a Mac - ac us and a cat, i. 30.
Kuppfer, Prof., on the affinity of the Ascidia to the Vertebrata, i. 205.
I.
Labidocera Darwinti , prehensile organs of the male, i. 329.
Labrus, splendid colours of the species of, ii. 16.
Labrus mixtus , sexual differences iu, ii. 9.
Labrus pavo, ii. 16.
Lacertilia, sexual differences of, ii. 32.
LAFRESNAYE.
INDEX.
LECKY.
441
Lafresnaye, M. de, on Birds of Paradise, ii. 78.
Lamarck, on the origin of man, i. 4.
Lamellibrancuiata, i. 324.
Lamkllicorn beetles, horn-like pro- j cesses from the head and thorax of, ! i. 370, 373 ; analogy of, to Rurnin- | ants, i. 373; influence of sexual i selection on, i. 377.
Lamellicornia, st ridulation of, i.380.
Lamont, Mr. on the tusks of tlie Walrus, ii. 242; on the use of its tusks by the Walrus, ii. 257.
Lampornis porphyrurus , colours of the female, ii. 168.
Lancelet, i. 204, 212.
Landois, H., on the production of sound by the Cicada?, i. 351 ; on the stridulating organ of the Crickets, i. 354 ; on fi$ct£cusf i. 355 ; on the stridulating organs of the Acri- diidae, i. 350 ; on the presence of rudimentary stridulating organs in some female Orthoptera, i. 359 ; on the stimulation of JS'ecrop/iorus, i. 378; on the stridulant organ of Cerambyx Aeros, i. 380; on the stridulating organs in the Coleo- ptera, i. 382 ; on the ticking of Anobium, i. 385 ; on the stridulant organ of Geotru-pes , i. 380.
Language an art, i. 55 ; articulate, origin of, i. 50 ; relation of the progress of, to the development of the brain, 1. 57 ; effects of inherit- ance in production of, i. 58 ; com- plex structure of, among barbarous nations, i. 61; natural selection in, i. 61 ; gesture, i. 232 ; primeval, i. 235 ; of a lost tribe preserved by a parrot, i. 236.
Languages, presence of rudiments in,
i. 60; classification of’ i. 60; vari- ability of, i. 60 ; crossing or blend- ing of, i. 60 ; complexity of, no test of perfection or proof of special creation, i. 62 ; resemblance of, evidence of community of origin, i. i89.
Languages and species, identity of evidence of their gradual develop- ment, i. 59.
Lanius , ii. 180 ; characters of young,
ii. 185.
Lanius rufus , anomalous young of, ii. 211.
Lankester, £, R., on comparative longevity, i. 168, 171; on the de- structive effects of intemperance, i. 173.
Lanugo, of the human foetus, i. 25 ; ii. 375.
Lapponian language, highly arti- ficial, i. 61.
Lark, proportion of the sexes in the,
i. 307 ; female, singing of the, ii. 54.
Larks, attracted hy a mirror, ii. 112.
LARTET, E., on the size of the brain in mammals, i. 51 ; comparison of cranial capacities of skulls of recent and tertiary mammals, i. 146; on Dryopithecus, i. 199.
Larus, seasonal change of plumage in,
ii. 228.
Larva, luminous, of a Brazilian beetle, i. 345.
Larynx, muscles of the, in song- birds, ii. 55.
Lasiocampa quercus , attraction of males by the female, i. 311 ; sexual difference of colour in, i. 398.
Latham, R. G,, on the migrations of man, i. 136.
Latooka, perforation of the lower lip by the women of, ii. 341.
Laotullaro, on the abnormal division of the malar bone in man, i. 124.
Lawrence, W., on the superiority of savages to Europeans in power of sight, i. 118; on the colour of negro infants, ii. 318 ; on the fond- ness of savages for ornaments, ii. 338 ; on beardless races, ii. 349 ; on the beauty of the English aris- tocracy, ii. 357.
I-AYARn, E. I,., on an instance of rationality in a Cobra, ii. 30; on the pugnacity of Oniliis Stanteyi , ii. 44.
Layc'OCK, Dr., on vital periodicity, i. 12.
Leaves, decaying, tints of, i. 323.
Lecky, Mr., on tho sense of duty, i. 71 ; ou suicide, i. 94 ; on the prac- tice of celibacy, i. 96; his view of the crimes of savages, i. 97 ; on the gradual rise of morality, i. 103.
442
LECONTE.
INDEX.
LIVINGSTONE.
Leconte, J. L., on the stridulant organ in the Coprini and Dynastini, i. 381.
Lee, H., on the numerical proportion of the sexes in the trout, i. 308.
Leg, calf of the, artificially modified, ii. 340.
Legitimate and illegitimate children, proportion of the sexes in, i. 302.
Legs, variation of the length of the, in man, i. 108 ; proportions of, in soldiers and sailors, i. 116; fore, atrophied in some male butterflies, i. 344 ; peculiarities of, in male insects, i. 344.
il Lek ” of the black-cock and caper- cailzie, ii. 100.
Lemoine, Albert, on the origin of language, i. 56.
Lemur macaco , sexual difference of colour in, ii. 290.
Lemuridas, i. 195 ; their origin, i. 213 ; position and derivation of the, i. 202 ; ears of the, i. 23 ; variability of the muscles in the,
i. 128.
Lemurs, uterus in the, i. 123 ; tail- less species of, i. 194.
Leopards, black, ii. 294.
Lepidoptera, i. 386 ; numerical pro- portions of the sexes in the, i. 309 ; colouring of, i. 387 ; ocellated spots of, ii. 132.
Lepidosiren , i. 204, 212.
Lenguas, disfigurement of the ears of the, ii. 341.
Lcptorhynchus angustatus , pugnacity of male, i. 375.
Leptura testacea , difference of colour in the sexes of, i. 367.
Lequay, on the occurrence of the supra-condyloid foramen in the humerus of man, i. 29.
LEROY, on the wariness of young foxes in hunting-districts, i. 50 ; on the desertion of their young by swallows, i. 84.
Lesse, valley of the, i. 29.
Lesson, on the Birds of Paradise, i. 269, ii. 98 ; on the sea-elephant,
ii. 278.
Lestis bombylans , difference of the sexes in, i. 366.
Zethrus cephalotes , pugnacity of the males of, i. 371, 376.
Leuckart, E., on the vesicula pro - statica , i. 31 ; on the influence of the age of parents on the sex of offspring, i. 302.
Ijcvator clmnculse muscle, i. 128.
Libcllula depressa , colour of the male? 1. 863*
Libellulid;e, relative size of the sexes of, i. 347 ; difference in the sexes of, i. 361.
Lice of domestic animals and man, i. 219.
Licentiousness, prevalence of, among savages, i. 96 ; a check upon pop11' lation, i. 134.
Lichtenstein, on Chera progne , li*
120.
Life, inheritance at corresponding periods of, i. 280, 285.
Ltght, supposed effects of, i.
influence of, upon the colours of shells, i. 326.
Lileord, Lord, the ruff attracted by bright objects, ii. 111.
Limosa lapponica , ii. 204.
Linaria , ii. 180.
IAnnria vnontana, i, 307.
LiNNiEUS, views of, as to the position of man, i. 190.
Linnet, numerical proportion of tllC sexes in the, i. 307 ; crimson for*' head and breast of the, ii.86 ; court- ship of the, ii. 94.
Linyphia , i. 337. r
Lion, polygamous, i. 268 ; mane 0 the, defensive, ii. 26 6 ; roaring 0 the, ii. 275.
Lions, stripes of young, ii. 183.
Lips, piercing of the, by savages, 1U
341.
of
Lithobius , prehensile appendages the female, i. 340.
Lithosia , coloration in, i. 396.
JAttorina Ultorea , i. 324.
Livingstone, Dr., on the inflnenc of dampness and dryness on 1 colour of the skin, i. 242; on liability of negroes to trop1^ fevers after residence in a c climate, i. 243; on the SP winged goose, ii. 47 ; on birds, ii. 63 ; on an African mgn jar, ii. 73, 97 ; on the foattle-sc of South African male mamm >
LIVONIA.
INDEX.
LUNAR.
443
ii. 239; on the removal of the upper incisors by the Batokas, ii. 340 ; on the perforation of the upper lip by the Makulolo, ii, 342 ; on the Banyai, ii. 347.
Livonia, numerical proportion of male and female births in, i, 301.
Lizards, relative size of the sexes of, ii. 32; gular pouches of, ii. 33.
Lloyd, L., on the polygamy of the capercailzie and bustard, i. 209 ; on the numerical proportion of the sexes in the capercailzie and black- cock, i. 306 ; on the salmon, ii. 5 ; on the colours of the sea -scorpion, ii. 9 ; on the pugnacity of male grouse, ii. 45; on the capercailzie and black-cock, ii. 49, 54; on the call of the capercailzie, ii. 61 ; ton assemblages of grouse and snipes, ii. 101 ; on the pairing of a shiehl- drake with a common duck, ii. 114; on the battles of seals, ii. 240 ; on the elk,ii. 249.
Lobivandlus , wing-spurs in, ii. 48,
Local influences, effect of, upon sta- ture, i. 114.
Lockwood, Mr., on the development of Hippocampus , i. 210.
Locust, bright-coloured, rejected by lizards and birds, i. 361.
Locust, migratory, i. 352.
Locustidje, stridulation of the, i. 352, 354; descent of the, i. 356.
Longicorn beetles, difference of the sexes of, in colour, i, 367 ; stridula- tion of, i. 380.
Lonsdale, Mr., on an example of per- sonal attachment in Helix pomatiiij
i. 325.
Lophobranchii, marsupial recep- tacles of the male, ii. 21.
lophophorus, habits of, ii. 121.
Lophonna (lira , sexual difference in coloration of, ii. 226.
Lophomis ornatus , ii. 76.
Lord, J. K., ou Salma lycaodon , ii. 5.
Lory, King, ii. 174; immature plum- age of the, ii. 188.
Love-antics and dances of birds,
ii. 68.
Lowne, B. T., on Musca vomitoria , i. 145, 349.
Loxia, characters of young of, ii. 184.
Lubbock, Sir J., on the antiquity of man, i. 3 ; on the origin of man, i. 4; on the mental capacity of sa- vages, i. 34 ; on the origin of imple- ments, i. 52 ; on the simplification of languages, i. 62 ; on the absence of the idea of God among certain races of men, i. 65 ; on the origin of the belief in spiritual agencies, i. 66 ; on superstitions, i. 69 ; on the sense of duty, i. 7 1 ; on the prac- tice of burying the old and sick among the Fijians, i. 77 ; non- prevalence of suicide among the lowest barbarians, i. 94; on the immorality of savages, 1. 97 ; on Mr. Wallace’s claim to the ori- gination of the idea of natural se- lection, i. 137 ; on the absence of remorse among savages, i. 164 ; on the former barbarism of civilised nations, i. 181 ; on improvements in the arts among savages, i. 182 ; on resemblances of the mental cha- racters in different races of men,
i. 232 ; on the power of counting in primeval mau, i. 234 ; on the arts practised by savages, i. 234 ; ou the prehensile organs of the male Labidocera Darwinii , i. 329 ; on Chloeon , i. 341 ; on Smynthut'us luteus , i. 348 ; on strife for women among the North American Indians,
ii. 324 ; ou music, ii. 334 ; on the ornamental practices of savages, ii. 338 ; on the estimation of the beard among the Anglo-Saxons, ii. 349 ; on artificial deformation of the skull, ii. 352 ; on “ communal marriages,” ii. 358, 360 ; on exo- gamy, ii. 360, 364; on the Veddahs, ii. 363 ; on polyandry, ii. 365.
LuCANiDvE, variability of the man- dibles in the male, i. 376.
Lucanus , large size of males of, i. 347.
Lucanus cervus, numerical proportion of sexes of, i. 313 ; weapons of the male, i. 375.
Lucanus elaphus , use of mandibles of, i. 377 ; large jaws of male, i. 342.
Lucas, Prosper, on sexual preference in horses and bulls, ii. 272.
Lunar periods, i. 212.
444
LUND.
INDEX.
M ‘NEILL.
Lund, Dr., on skulls found in Bra- zilian caves, i. 218.
Lungs, enlargement of, in the Que- chua and Aymara Indians, i. 119; a modified swim-bladder, i. 207 ; different capacity of in races of man, i. 216.
Luminosity in insects, i. 34-5.
Luschka, Prof., on the termination of the coccyx, i. 30.
Lust, instinct of, i. 89.
Luxury, comparatively innocuous, i. 171.
Lycxna, sexual differences of colour- ing in species of, i. 390.
Lyell, Sir C., on the antiquity of man, i. 3 ; on the origin of man, i. 4; on the parallelism of the de- velopment of species and languages,
i. 59 ; on the extinction of lan- guages, i. 60 ; on the Iuquisition, i. 178; on the fossil remains of ver- tebrata, i, 201; on the fertility of mulattoes, i. 221.
Lynx, Canadian, throat-ruff of the,
ii. 267.
Lyre-bird, assemblies of, ii, 101.
M.
Macacus , ears of, i. 23; convoluted body in the extremity of the tail of, i. 30; variability of the tail in species of, i. 150; whiskers of species of, ii. 283.
Macacus cynomolgus , superciliary ridge of, ii. 318 ; beard and whis- kers of, becoming white with age, ii. 319.
Macacus inornatus , i. 151.
Macacus lasiotus , facial spots of, ii. 308.
Macacus radiatus, i. 192.
Macacus rhesus, sexual difference in the colour of, ii. 293, 310.
Macalister, Prof., on variations of the palmaris accessorius muscle, i. 109 ; on muscular abnormalities in man, i. 128, 129 ; on the greater variability of the muscles in men than in women, i. 275.
Macaws, Mr. Buxton’s observations on, i. 76 ; screams of, ii. 61.
McCann, J., on mental individuality, i. 63.
McClelland, J., on the Indian cypn- nidge, ii. 17.
Maccullooh, Col., on an Indian vil- lage without any female children? ii. 364.
Maccullocij, Dr., on tertian ague in a dog, i. 13.
Macgillivray, W., on the vocal organs of birds, i. 59 ; on the Egyptian goose, ii. 48; on the habits of woodpeckers, ii. 63 ; on the habits of the snipe, ii. 64; on the whitethroat, ii. 69; on the moulting of the snipes, ii. 82 ; on the moulting of the anatidsc, ii* 8o ? on the finding of new mates by. magpies, ii. 103; on the pairing m a blackbird and thrush, ii* on pied ravens, ii. 126 ; on the guillemots, ii. 127 ; on the colour-’ of the tits, ii. 174 ; on the im- mature plumage of birds, ii* et seqq.
Machetes , sexes and young of, ii* 219-
Machetes pugnax, numerical pr°P01 - tion of the sexes iu, i. 306 ; sup- posed to be polygamous, i* 279 , pugnacity of the male, ii. 41 ; double moult in, ii. 81.
Mackintosh, on the moral sense,
70.
MacLaciilan, R., on Apatania rnu~ liebris and Boreus hyenudis, i* 31 » on the anal appendages of ma e insects, i. 342; on the pairing °* dragon-flies, i. 347 ; on dragon- flies, i. 362, 363; on dimorphism in Agrion, i. 363 ; on the want 0 pugnacity in male dragon-flies, n 364 ; on the ghost-moth in 10 Shetland Islands, i. 402.
McLennan, M i*., on the origin of tn . belief iu spiritual agencies, i* ’ on the prevalence of licentiousnes^ among savages, i. 90, ii* 358 ; f infanticide, i. 134, ii. 363; °n primitive barbarism of civilised m tions, i. 181 ; on traces of the c tom of the forcible capture of wiv i. 182, ii. 365; on polyandry, •
365.
McNeill, Mr
on the use of the ant lers of deer, ii. 252 ; on the co
deerhound, ii. 261 ; on
the long
MACRORIIINUS.
INDEX.
MANTELL.
445
hairs of the throat of the stag, ii. 268 ; on the bellowing of stags, ii. 274.
Macrorhinus proboscides, structure j of the nose of, ii. 278.
Magpie, power of speech of, i. 59 ; stealing bright objects, ii. 112; nuptial assemblies of, ii. 102 ; new mates found by, ii. 103; young of the, ii. 209 ; coloration of the, ii. 230.
Magpies, vocal organs of the, ii. 55.
Maillard, M., on the proportion of the sexes in a species of Papilio from Bourbon, i. 310.
Maine, Mr., on the absorption of one j tribe by another, i. 169; on the ' want of a desire for improvement, i. 166.
Makalolo, perforation of the upper lip by the, ii. 341.
Malar bone, abnormal division of, in man, i. 124.
Malay, Archipelago, marriage-cus- toms of the savages of the, ii. 373.
Malays, line of separation between the Papuans and the, i. 218 ; gene- ral beardlessness of the, ii, 821 ; staining of the teeth among, ii. 339 ; aversion of some, to hairs on the face, ii. 349.
Malays and Papuans, contrasted cha- racters of, i. 216.
Male animals, struggles of, for the possesion of the females, i. 269, 260; eagerness of, iu courtship, i. ( 272, 273 ; generally more modified i than female, i. 272, 275; differ in the same way from females and young, i. 285.
Male characters, developed in fe- males, i. 280 ; transfer of, to female birds, ii. 193.
Male, sedentary, of a hymenopterous parasite, i. 272.
Malefactors, i. 172.
Males, presence of rudimentary fe- male organs in, i. 208.
Males and females, comparative mor- tality of, while young, i. 264, 276; j comparative numbers of, i. 261, 1 263.
Malherbe, on the woodpeckers, ii. 1 174.
Maltiius, T., on the rate of increase of population, i. 131, 132, 134.
M altjridas, nidification of the, ii. 1G9.
Malunis, young of, ii. 216,
Mammas, i. 254 ; rudimeutary, in male mammals, i. 17, 30, 208, 209, 210 ; supernumerary, in women, i. 125 ; of male human subject, i. 130.
Mammalia, Prof. Owen’s classification of, i. 187 ; genealogy of the, i. 203.
Mammals, secondary sexual charac- ters of, ii. 239 ; weapons of, ii. 241 ; recent and tertiary, compa- rison of cranial capacity of, i. 146 ; relative size of the sexes of, ii. 260; pursuit of female, by the males, i. 272 ; parallelism of, with birds in secondary sexual charac- ters, ii. 297 ; voices of, used espe- cially during the breeding season, ii. 331.
Man, variability of, i. 108; errone- ously regarded as more domesti- cated than other animals, i. Ill ; definitive origin of, i, 235 ; migra- tions of, i. 135 ; wide distribution of, i. 137 ; causes of the nakedness of, i., 149 ; supposed physical infe- riority of, i. 156 ; numerical pro- portions of the sexes in, i. 264 ; a member of the Catarrh iue group,
i. 198; early progenitors of, i. 206; secondary sexual characters of, ii. 316 ; primeval condition of, ii. 367.
Mandans, correlation of colour and texture of hair in the, i. 248.
Mandible, left, enlarged in the male of Tap hr ochres distort ns, l 344.
Mandibles, use of the, in Ammo- phila, i. 342; large, of Corydalis cornuius, i. 842 ; large, of male Lecanus elaphus , i. 342.
Mandrill, number of caudal verte- brae in the, i. 150; colours of the male, ii. 292, 296, 810.
Mantegazza, Prof., on the orna- ments of savages, ii. 338 <-t seqq. ; on the beardless n ess of the New Zea- landers, ii. 349 ; on the exaggera- tion of natural characters by man,
ii. 351.
Mantell, W.} on the engrossment of
446
MANTIS.
INDEX.
METALLURA.
pretty girls by the New Zealand chiefs, ii. 369.
Mantis , pugnacity of species of, i. 360.
Marcus Aurelius, on the origin of the moral sense, i. 71; on the in- fluence of habitual thoughts, i. 101.
Mareca penelope, ii. 114.
Marks, retained throughout groups of birds, ii. 131.
Marriage, influence of, upon morals, i. 96 ; restraints upon, among savages, i. 133; influence of, on mortality, i. 175 ; development of, ii. 361.
Marriages, communal, ii. 358, 360; early, i. 174, 175.
Marshall, Mr., on the brain of a Bush woman, i. 216.
Marsupials, i. 202; possession of nipples by, i, 209 ; their origin from Monotremata, i. 213 ; uterus of, i. 122 ; development of the nic-
’ titating membrane in, i. 23; ab- dominal sacks of, i. 254; relative size of the sexes of, ii. 260 ; colours of, ii. 286.
Marsupium, rudimentary, in male marsupials, i. 208.
Martin, W. C. L., on alarm mani- fested by an orang at the sight of a turtle, i. 43 ; on the hair in Uy lo- cates, i. 194; on a female American deer, ii. 258 ; on the voice of Uulo- bates ay ills, ii. 277 ; on Scmnopilhe- cus nemmus, ii. 312.
Martin, on the beards of the inhab- itants of St. Kilda, ii. 321.
Martins deserting their young, i. 84.
Martins, C., on death caused by in- flammation of the vermiform ap- pendage, i. 28.
Mastoid processes in man and apes, i. 143.
Maudsley, Dr., on the influence of the sense of smell in man, i. 24; on Laura Bridgman, i. 58 ; on the development of the vocal organs, i. 59.
Mayers, W. F., on the domestication of the goldfish in China, ii. 17.
Mayhew, E., on the affection between individuals of different sexes in the dog, ii. 270.
Maynard, C. J., on the sexes of Chry- semys picta, ii. 28.
Meckel, on correlated variation 0 the muscles of the arm and leg? 1# 130.
Medicines, effect produced by, same in man and in monkeys, i- Meduste, bright colours of some, J* 322. ,
Megalitiiic structures, prevalence o , 1. 233.
Megalophrys montana , sexual dine* ences in, ii. 26, 27.
Meyapieus mlidus , sexual difference colour in, ii. 174. j
Megasoma, large size of males or, •
347. • the
Meigs, Dr. A., on variation m skulls of the natives of America, 108.
Meinecke, on the numerical prop01 tion of the sexes in butterflies? 309. .
MelipiiagiD/E, Australian, nidified tion of, ii. 169. ^
Melita , secondary sexual characters o ?
i. 331. . fhe
Melos', difference of colour m sexes of a species of, i. 367. .
Memory, manifestations of, in A mals, i, 45.
Memnon, young, i. 217.
Mental characters, difference
of, &
different races of men, i. 216* ,
Mental faculties, variat ion of, 111 . same species, i. 36, 110; diyei^.^ of, in the same race of men, i* ’■
m me same race "i . 0p
eritance of, i. 110; simiUy1^^, in different races of man, i« - ?
inher the.
of birds, ii. 108.
Mental powers, difference of, lD two sexes in man, ii. 326. Menura Alberti , ii. 102 ; song
th°
of,
Menura superba , ii. 101, 102?
tails of both sexes of, ii. 104. Merganser, trachea of the ma ?
00- . i 291-
Meryus cucuUatus, speculum o*? Meryus merganser , youug of, H* ^ 0£ Merganser serrator , male plumbs ii. 85. ^ e ii.
Metallura, splendid tail-featheis ? 152.
METIIOCA.
INDEX.
MONSTROSITIES.
447
Methoca ichneumonides, large male of,
i. 347.
Meves, M., on the drumming of the snipe, ii. 63.
Mexicans, civilisation of the, not foreign, i. 183.
Meyer, on a convoluted body at the extremity of the tail in a Macacus and a cat, i. 30.
Meyer, Dr. A., on the copulation of phryganidse of distinct species, i, 342.
Migrations of man, effects of, i. 135. Migratory instinct of birds, i. 79;
vanquishing the maternal, i. 83, 90. Mill, J. S., on the origin of the moral sense, i. 71 ; on the “ greatest hap- piness principle,” i. 97 ; on the dif- ference of the men t,;il powers in the sexes of man, ii. 328.
Millipedes, i. 339.
Mi lne-Ed wards. H., on the use of the enlarged chela of the male Ge~ lasiinus , i. 331.
Milvaqo leucurus , sexes and young of,
ii. 205.
Mimickry, i. 411.
Mimus potuglottus, ii. 109.
Mind, difference of, in man and the highest animals, i. 104; similarity of the, in different races, i. 232. Minnow, proportion of the sexes in the, i. 308, 309.
Minnows, spawning habits of, ii. 15. Mirror, larks attracted by, ii. 112. Mivart, St. George, on the reduction of organs, i. 18; on the ears of the lemuroidea, i. 25; on variability of the muscles in lemuroidea, i. 128, 13G ; on the caudal vertebr.e ot monkevs, i. 150; on the classifica- tion of the primates, i. 196 ; on the I orang and on man, i. 197 ; on dif- ] ferences in the lemuroidea, i. 198 ; J on the crest of the male newt, ii. 24. | Mocking-thrush, partial migration of, ii. 109; young of the, ii- 219.^ Modifications, unserviceable, i. 153. Moles, numerical proportion of the sexes in, i. 305 ; battles ol male, ii. 239.
Mollienesia petenensis , sexual differ- ence in, ii. 9.
Mollusca, beautiful colours and
shapes of, i. 326 ; absence of secon- dary sexual characters in the, i. 324.
Molluscoipa, i. 205, 324.
Monacanthus scopas and M. Peronii , sexual differences in, ii. 12.
Mongolians, perfection of the senses in, i. 119.
Monkey, protecting his keeper from a baboon, i. 78, 87; bonnet.-, i. 192 ; rhesus, sexual difference in colour of the, ii. 293, 310 ; moustache-, colours of the, ii. 291,
Monkeys, liability of, to the same diseases as man, i. 11 ; male, recog- nition of women by, i. 13 ; revenge taken by, i. 40 ; maternal affection in, i. 40 ; variability of t.he faculty of attention in, i. 44 ; using stones and sticks, i. 51 ; imitative faculties of, i. 56 ; signal-cries of, i. 57 ; sen- tinels posted by, i. 74; diversity of the mental faculties in. i. 110; mutual kindnesses of, i. 75; hands of the, i. 139, 140 ; breaking hard fruits with stones, i. 140; basal caudal vertebrae of, imbedded in the body, i. 151 ; human characters of, i. 191; gradation of species of,
i. 227 ; beards of, ii. 283 ; orna- mental characters of, ii, 306 ; ana- logy of sexual differences of, with those of man, ii. 318; different degrees of difference in the sexes of,
ii. 323 ; expression of emotions by, ii. 336; generally monogamous habits ol, ii. 361 ; polygamous habits of some, ii. 362 ; naked sur- faces of, ii. 376; American, mani- festation of reason in, i. 47; Ameri- can, direction of the hair on the arms of some, i. 192.
Monogamy, not primitive, i. 182.
Monog exists, i. 228.
Mononychus pseudo, cori, stridulation of, i. 382.
Monotremata, i. 202; development of the nictitating membrane in, i. 23 ; lactiferous glands of, i. 209 ; connecting mammals with reptiles, i. 213.
Monstrosities, analogous, in man and lower animals, i. 113; caused by arrest of development, i. 121 ;
448
MONTAGU.
INDEX.
MURIE.
correlation of, i. 130 ; transmission of, i. 224.
Montagu, G., on the habits of the black and red grouse, i. 209 ; on the pugnacity of the ruff, ii. 41 ; on the singing of birds, ii. 52; on the I double moult of the male pintail, ii. 84.
MONTEUtO, Mr., on Buoorax ahys- sinicuSy ii. 72.
Montes de Oca, M., on the pug- nacity of male Humming-birds, ii. 40.
Monttcola cyanea , ii. 172.
Monuments, as traces of extinct tribes, i. 237.
Moose, battles of, ii. 240; horns of the, an incumbrance, ii. 259.
Moral and instinctive impulses, al- liance of, i. 8.8.
Moral faculties, their influence on natural selection in man, i. 158.
Moral rules, distinction between the higher and lower, i. 100.
Moral sense, origin of the, i. 102 ; so-called, derived from the social instincts, i. 97, 98.
Moral tendencies, inheritance of, i.
102.
Morality, supposed to be founded in selfishness, i. 97 ; test of, the general welfare of the community, i. 98 ; gradual rise of, i. 103 ; in- fluence of a high standard of, i. 166. ’
Morgan, L. H., on the Beaver, i. 37 ; on the reasoning powers of the Beaver, i. 46 ; on the forcible capture of wives, i. 182; on the castoreum of the beaver, ii. 279 * marriage unknown in primeval times, ii. 359; on Polyandry, ii. 365.
Morris, F. O., on hawks feeding an orphan nestling, ii. 107.
Mortality, comparative, of females and males, i, 264, 276, 302.
Morton, on the number of species of man, i. 226.
Moschns moschiferuSy odoriferous or- gans of, ii. 280.
MotaciWe, Indian, young of, ii. 190.
Moths, i. 394 ; absence of mouth in some male, i. 254; apterous female,
i. 255 ; male, prehensile use of the tarsi by, i. 256 ; male, attracted by females, i. 311 ; coloration of, h 397 ; sexual differences of colon1’ in, i. 398.
Motmot, racket-shaped feathers 111 the tail of a. ii. 73.
Moult, double, ii. 181; double an- nual, in birds, ii. 80.
Moulting of birds, ii. 214.
Moults, partial, ii. 83.
Moustache-monkey, colours of the,
ii. 291, 311.
Moustaches, in monkeys, i. 192.
Mud-turtle, long claws of the male? ii. 28.
Mulattoes, persistent fertility of, >• 221 ; immunity of, from yellow fever, i. 243.
Mule, sterility and strong vitality 0 the, i. 221.
Mules, rational, i. 48,
Muller, Ferd., on the Mexicans an Peruvians, i. 183.
Muller, Fritz, on astomatous males of Tm riSy i. 255 ; on the disappear' ance of spots and stripes in adul mammals, ii. 305; on the proper* tions of the sexes in some Crns- tacea, i. 315; on secondary sex«a characters in various Crustaceans, i. 328 et seqq. ; on the lumin°u® larva of a beetle, i. 345 ; niusica contest between male Cicad&i 1' 351 ; on the sexual maturity 0 young amphipod Crustacea, ii- 21 *
Muller, J., on the nictitating mem- brane and semilunar fold, i. 23.
MOller, Wax, on the origin of 1»“* guage, i. 56 ; struggle lor 11 e among the words, &c., of language i. 60.
MiiLLKR, S., on the Banteng, ii- 290 1 on the colours of S&mttopith^ chry&omelas, ii. 291.
MitNTJAc-DEEit, weapons of the, "• 257 .
Murie, J., on the reduction of m gans, i. 18; on the ears of t Lemuroidea, i, 23 ; on variabm ] of the muscles in the Leniurou ^ i. 128, 136; basal caudal of Macacus innmatus irabeddec the body, i. 151; on differences
MURRAY.
INDEX.
NECK.
449
the Lemuroidea, i. 198 ; on the throat-pouch of the male Bustard, ii. 58 ; on the mane of Otariajubata , ii. ‘267 ; on the sub-orbital pits of Ruminants, ii. 280; on the colours of the sexes in Otaria niffrcscens , ii. 287. Murray, A., on the PecUculi of dif- ferent races of men, L 219.
Murray, T. A., on the fertility of Australian women with white men, i. 220.
Mus coninga , i. 50.
mmittus. sexual difference in the ' colour of, ii. 286. ifwsca tomitoria, i. 145.
Muscicapa yrisola, ii. 170.
Muscicapa luctuosa , ii. 170.
Muscicapa ruticilla , breeding in im- mature plumage, ii. 214.
Muscle, ischio-pubic, i. 127.
Muscles, rudimentary, occurrence of, in man, i. 19 ; variability of the, i. 109 ; effects of use and disuse upon, i. 116; animal-like abnormalities of, in man, i. 127 ; correlated variation of, in the arm aud leg, i. 130; vari- ability of, in the hands and feet, i. 136; of the jaws, influence of, on the physiognomy of the Apes, i. 144; habitual spasms of, causing modi- lications of the facial bones, i. 147 ; of the early progenitors of man, i. 206 ; greater variability of the, iu men than in women, i. 275. Musculus sternalts, Prof. Turner on ■ the, i. 19.
Music, i. 232; of birds, ii. 51; dis- cordant, love of savages for, ii. 07 ; different appreciation of, by diffe- rent peoples, ii. 333 ; origin of, ii, 333, 387 ; effects of, ii. 335.
Musical cadences, perception of, by animals, ii. 333 ; powers of inan, ii. i 330 et seqq.
Musk-deer, canine teeth of male, ii. | 241, 256, 257; male, odoriferous j organs of the, ii. 280; winter j change of the, ii. 299.
Musk-duck, Australian, ii. 38 ; large size of male, ii. 43 ; of Guiana, pug- j nacity of the male, ii. 43.
Musk-ox, horns of, ii. 247.
Musk-rat, protective resemblance of the, to a clod of earth, ii. 298.
VOL. II.
Musophagx, colours and nidification of the, ii. 171 ; both sexes of, equally brilliant, ii. 177.
Mussels opened by monkeys, i. 140.
Musteln, winter change of two species of, ii. 298.
Mutilations, healing of, i. 13.
Mutilla europsea , stridulation of, i. 366.
Mutillidas, absence of ocelli in fe- male, i. 341.
My cat as caraya , polygamous, i. 266 ; vocal organs of, ii. 277 ; beard of, ii. 283; sexual differences of colour in, ii. 290; voice of, ii. 332.
Mycetes seniculus , sexual differences of colour in, ii. 290.
Myriapod a, i. 339.
N.
Nageli, on the influence of natural selection on plants, i. 152 ; on the gradation of species of plants, i. 227.
Nails, coloured yellow or purple in part of Africa, ii. 339.
Naples, greater proportion of female illegitimate children in, i. 30 L.
Narwhal, tusks of the, ii. 242, 248.
Nasal cavities, large size of, in Ame- rican aborigines, i. 119.
Nascent organs, i. 18.
Nath usi us, H. von, on the improved breeds of pigs, i, 230 ; on the breed- ing of domestic animals, ii. 370.
Natural selection, its effects on the early progenitors of man, i. 136 ; influence of, on man, i. 151, 154 ; limitation of the principle, i. 152; influence of, on social animals, i. 155 ; Mr. Wallace on the limitation of, by the influence of the mental faculties in man, i. 158; influence of, in the progress of the United States, i. 179.
Natural and sexual selection con- trasted, i. 278.
Naulette, jaw from, large size of the canines in, i. 120.
Neanderthal skull, capacity of the, i. 146.
Neck, proportion of, in soldiers and sailors, i. 117.
2 G
450
NECROPHORl/S.
INDEX.
NUNEMAYA.
KecrophoruSj stridulation of, i. 378, 382.
Nectarinia , young of, ii. 190.
Nectarinm, nidifi cation of, ii. 169; moulting of the, ii, 83.
Negro, resemblance of a, to Europe- ans, in mental characters, i. 232.
Negro-women, their kindness to Mungo Park, i. 95.
Negroes, character of, i. 216 ; lice of, i. 220 ; blackness of, i. 224, ii. 381 ; variability off i. 225, 226 ; immunity of, from yellow fever, i. 243 ; dif- ference off from Americans, i. 247 ; disfigurements of the, ii. 296; colour of new-born children of, ii. 318 ; comparative beardlessness of, ii. 321 ; readily become musicians, ii. 334 ; appreciation of beauty of their women by, ii. 344, 346 ; idea of beauty among, ii. 350; compres- sion of the nose by some, ii. 352.
Neolithic period, 183.
Neomorpha , sexual difference of the beak in, ii. 39.
Nephila , i. 337.
Nests, made by fishes, ii. 19 ; decora- tion of, by Humming-birds, ii. 112.
Neijmeister, on a change of colour in pigeons after several moultiugs, i. ^ 294.
Neuration, difference off in the two sexes of some butterfiies and hym- enoptera, i. 345.
Neuroptera, i. 814, 361.
ISeuj'othemis. dimorphism in, i. 363.
New Zealand, expectation by the na- tives off of their extinction, i. 240 ; practice of tattooing in, ii. 342; aversion of natives off to hairs on the face, ii. 349; pretty girls en- grossed by the chiefs in, ii. 309.
Newton, A., on the throat-pouch of the male bustard, ii. 58; on the difference between the females of two species of Oxynotus , ii. 193 • on the habits of the phularope, dotterel, and godwit, ii. 204.
Newts, ii, 24.
Nicholson, Dr., on the non-immunity of dark Europeans from yellow fever, i. 245.
Nictitating membrane, i. 23, 207.
Nidieication, of fishes, ii. 19 ; relation
off to colour, ii. 167, 172; British birds, ii. 169.
Night-heron, cries of the, ii. 51.
Nightingale, arrival of the malff before the female, i. 259 ; object of the song of the, ii. 52.
Nightingales, new mates found by> ii. 105.
NigiitjaPv, selection of a mate by the female, ii. 116; Australian, sexeS off ii. 206 ; coloration of the, ii* 226.
Nightjars, noise made by some male? with their wings, ii. 62 ; elongated feathers in, ii. 73, 97.
Nilghau, sexual differences of colon1 in the, ii. 287.
Nilsson, Prof., on the resemblance °f stone arrow-heads from vari°113 places, i. 233 ; on the development of the horns in the reindeer, i. 285-
NirPLES, absence off in Monotremata,
i. 209.
Nttzsch, C. L., on the down of bird^
ii. 80.
Nocture, brightly-coloured beneath?
i. 397.
Noctuid/E, coloration off I. 394.
.Nordmann, A., on Tetrao urogalloi&s »
ii. 100.
Nomadic habits, unfavourable human progress, i. 167.
Norway, numerical proportion 0 male and female births in, i. 30l*
Nose, resemblance of, in man and the apes, i. 192 ; piercing and orna' mentation of the, ii. 341 ; flatten* ing of the, ii. 352 ; very flat, n° admired in negroes, ii. 350. *
Nott and (Hidden, on the features 0 Ramoses 11., i. 217 ; on the feature5 of Aniunoph lit., 1.218; on ski"" from Brazilian cares, i. 218 ; on tiu immunity of negroes and mulatto®* from yellow fever, i. 243 ; on "V deformation of the skull am0113 American tribes, ii. 352.
Num BRANCH molluscs, bright colour’ of, i. 326.
Numerals, Roman, i. 182.
Nunemata, natives of, bearded 1 • 322, 349.
OBEDIENCE.
INDEX.
ORYCTES.
451
o.
Obedience, value of, i. 162.
Observation, powers of, possessed by birds, iL 109.
Occupations, sometimes a cause of diminished stature, i. 115; effect of, upon the proportions of the body, i. 116.
Ocelli, absence of, in female Mutil- lidse, i. 341.
Ocelli of birds, formation and vari- ability of the, ii. 132.
Ocelot, sexual differences in the colouring of the, ii. 287.
Ocyphdps lophot.es, ii. 96.
Odonata, i. 314.
Odonestis potatoria , sexual difference of colour in, i. 398.
Odour, correlation of, with colour of skin, i. 248 ; emitted by snakes in the breeding-season, ii, 30 ; of mammals, ii. 278.
Oecanthus nivalis , difference of colour in the sexes of, i. 361.
Oiclemia , ii. 226, 227.
Olivier, on sounds produced by Pimelia striata , i. 385.
Omaloplia hrunnea , stridulation of, i. 381.
Onitis furcifer , processes of anterior | femora of the male, and on the head and thorax of the female, i. 372.
Onthophagus, i. 370.
Ontkophagus rangifer , sexual differ- ences of, i. 369; variation in the horns of the male, i. 370.
Ophtdia, sexual differences of, ii. 29.
Opossum, wide range of, in America, i. 219.
Optic nerve, atrophy of the, caused by destruction of the eye, i. 116.
Orang-Outan, ii. 323 ; Bischoff on the agreement of the brain of the, with that of man, i. 11 ; adult age of the, i. 13 ; ears of the, i. 21 ; ver- miform appendage of, i. 27 ; plat- forms built by the, i. 36 ; alarmed at the sight of a turtle, i. 43 ; using a stick as a lever, i. 51 ; using missiles, i. 52 ; using the leaves of the Pandanus as a night covering, i. 53 ; hands of the, i.
139 ; absence of mastoid processes in the, i. 143 ; direction of the hair on the arms of the, i. 192 ; its aberrant characters, i. 197 ; sup- posed evolution of the, i. 230 ; voice of the, ii. 276 ; monogamous habits of the, ii. 361 ; male, beard of the, ii. 284.
Oranges, treatment of, by monkeys, i. 139.
Orange-tip butterfly, i. 388, 393, 394.
Orchestia Darwinii, dimorphism of males of, i. 332.
Orchestia Tucuratinga , limbs of, i. 330, 331, 337.
Ordeal, i. 68.
Oreas canna , colours of, ii. 288.
Orcas Derbianus , colours of, ii. 288, 299.
Organs, prehensile, i. 256 ; utilised for new purposes, ii. 335.
Organic scale, von Baer’s definition of progress in, i. 211.
Orioles, nidification of, ii. 167.
Oriolus , species of, breeding in im- mature plumage, ii. 214, 215.
Oriolus melnnocephalm , coloration of the sexes in, ii. 178.
Ornaments, prevalence of similar, i. 233 ; fondness of savages for, ii. 338 ; of male birds, ii. 50.
Ornamental characters, equal trans- mission of, to both sexes, iu mam- mals, ii. 297 ; of monkeys, ii. 306.
Ornithoptera crccsus, i. 310.
Ornithorhynchus , i. 200 ; spur of the male, ii. 242 ; reptilian tendency of, i. 204.
Orocetes erythrogastra , young of, ii. 219.
Orhony, Grotto of, i. 28.
Orsodacna atra , difference of colour in the sexes of, i. 368.
Orthoptera, i. 352 ; metamorphosis of, i. 292; stridulating, auditory apparatus of, i. 353 ; colours of, i. 360 ; rudimentary stridulating or- gans in female, i. 359 ; stimula- tion of the, and Homoptera, dis- cussed, i. 360.
Ortygornis gularis , pugnacity of the male, ii. 44.
Oryctes , stridulation of, i. 381 ; sexual
2 a 2
452
ORYX.
INDEX.
PALLAS.
differences in the stridulant organs of, i. 383.
Oryx leucoryx , use of the horns of, ii. 251, 263.'
Osphrantcr rufus, sexual difference in the colour of, ii. 286.
Ostrich, African, sexes and incuba- tion of the, ii. 205.
Ostriches, stripes of young, ii. 184.
Qtw'ia jubata , mane of the male, ii. 267.
Otaria nigresccns, difference in the coloration of the sexes of, ii. 287.
Otis bengalensiSj love-antics of the male, ii. 68.
Otis tarda , polygamous, i. 269; throat- pouch of the male, ii. 58.
Ouzel, ring-, colours and nidifieation of the, ii. 179.
Ouzel, water-, colours and nidifica- tion of the, ii. 170.
Ovibos moschatus , horns of, ii. 247.
Ovipositor of insects, i. 254.
Otm cycloceros , mode of fighting of, ii. 249.
Ovule of man, i. 14.
Owen, Prof., on the Corpora Wolffiana, i. 16; on the great toe in man, i. 1 6 ; on the nictitating membrane and semilunar fold, i. 23; on the development of the posterior mo- lars in different races of man, i. 26 ; on the length of the ccecum ia the Koala, i. 27 ; on the coccygeal ver- tebrae, i. 29 ; on rudimentary struc- tures belonging to the reproductive system, i. 31; on abnormal condi- tions of the human uterus, i. 123 ; on the number of digits in the Ichthyopterygia, i. 125; on the canine teeth in man, i. 126 ; on the walking of the chimpanzee and orang, i. 139 ; ou the mastoid pro- cesses in the higher apes, i. 143; on the hairiness of elephants in elevated districts, i. 149 ; on the caudal vertebrae of monkeys, i. 150 ; classification of mammalia, i. 187 ; on the hair in monkeys, i. 194 ; on the piscine affinities of the Ichthyosaurians, i. 204; on poly- gamy and monogamy among the •antelopes, i. 267 ; on the horns of Antilocapra americana, i. 289 ; on
the musky odour of crocodiles during the breeding season, ii. 29 ; on the scent-glands of snakes, ii« 30; on the Dugong, Cachalot and Ornithorhynchus , ii. 242 ; on the autlers of the red deer, ii. 252 ; on the dentition of the camelidse, ii* 257 ; on the tusks of the Mam- moth, ii. 258 ; on the horns of the Irish elk, ii. 259 ; ou the voice in the giraffe, porcupine, and stag, ii. 274; on the laryngeal sac of the gorilla and orang, ii. 276 ; on the odoriferous glands of mammals, ii. 279, 280; on the effects of emas- culation on the vocal organs of men, ii. 330; on the voice of Jlylo - bates agiliSy ii. 332; on American monogamous monkeys, ii., 362.
Owls, white, new mates found by, ii* 105.
Oxynotas , difference of the females of two species of, ii. 193.
P.
Pachyderm at a, i. 268,
PAGET, on the abnormal develop- ment of hairs in man, i. 25 ; on the thickness of the skin on the soles of the feet of infants, i. 118*
Painting, i. 232.
Palmmon, chela* of a species of, i. 331-
Palmornis, sexual differences of colour in, ii. 231*
Palma mis javanicus , colour of beak of, ii. 179.
Palmornis rosa, young of, ii. 188.
Palamedea cornuta , spurs on the wing5 ii. 47.
Paleolithic period, i. 183.
Palestine, habits of the chaffinch in* i. 307,
Pallas, on the perfection of f^e seuses in the Mongolians, i. 119 » 011 the want of connexion between cli- mate and the colour of the skin, *• 241 ; on tiie polygamous habits ot Antilope Saiga , i. 267 ; on flje lighter colour of horses and cattie in winter in Siberia, i. 282 ; on tke tusks of the musk-deer, ii- 25 » 258; on the odoriferous glands 0 mammals, ii. 279 ; on the odorife*
PALMARIS.
INDEX.
PEACOCK.
453
rous glands of the musk-deer, ii. ' 280 ; on winter changes of colour in mammals, ii. 298 ; on the ideal of female beauty in North China, ii. 344.
Palmaris accessorius muscle , variations I of the, i. 109.
Pampas, horses of the, i. 236.
Pangenesis, hypothesis of, i. 280, 284.
Panniculus carnosus, i. 19.
Papilio , sexual differences of colour- ing in species of, i. 389 ; propor- tion of the sexes in North Ame- rican species of, i. 309 ; coloration of the wings in species of, i. 396.
Papilio ascanius, i. 389.
Papilio Scsostris and Childrens, varia- bility of, i. 402.
Papilio TurnuSj i. 310.
Papilionidje, variability in the, i. 402.
Papuans, line of separation between the, and the Malays, i. 218; beards of the, ii. 322 ; hair of, ii. 340.
Papuans and Malays, contrast in cha- racters of, i. 216.
Paradise, Birds of, ii. 100, 181 ; sup- posed by Lesson to be polygamous,
i. 260 ; rattling of their quills by,
ii. 61 ; racket-shaped feathers in, ii. 73 ; sexual differences in colour of, ii. 76 ; decomposed feathers in, ii. 74, 97 ; display of plumage by the male, ii. 88.
Paradisea apoda, barbless feathers in the tail of, ii. 74 ; plumage of, ii. 78 ; and P. papuana , divergence of the females of, ii. 192.
Paradisea rubra , ii. 75, 78.
Paraguay, Indians of. eradication of eyebrows and eyelashes by, ii. 348.
Parakeet, Australian, variation in the colour of the thighs of a male, ii. 126.
Parallelism of development of spe- cies and languages, i. 59.
Parasites on man and animals, i. 12 ; as evidence of specific identity or distinctness, i. 219; immunity from, correlated with colour, i. 242.
Parental affection, partly a result of natural selection, i. 81.
Parents, age of, influence upon sex of offspring, i. 302.
Parin.e, sexual difference of colour in, ii. 174.
Park, Mungo, negro-women teaching their children to love the truth, i. 95 ; his treatment by the negro- women, i. 95, 326 ; on negro opi- nions of the appearance of white men, ii. 346.
Parrot, racket-shaped feathers in the tail of a, ii. 73; instance of benevolence in a, ii. 109.
Parrots, imitative faculties of, i. 44; change of colour in, i. 152; living in triplets, ii. 106 ; affection of, ii. 108 ; colours of, ii. 223 ; sexual differences of colour in, ii. 231 ; colours and nidification of the, ii. 171, 174, 176 ; immature plumage of the, ii. 188; musical powers of, ii. 335.
Parthenogenesis in the Tenthredi- nsc, i. 314 ; in Cympidse, i. 314 ; in Crustacea, i. 315.
Partridge, monogamous, i. 269 ; proportion of the sexes in the, i. 306 ; female, ii. 194.
“ Partridge-dances,” ii, 68.
Partridges, living in triplets, ii. 106 ; spring coveys of male, ii. 107 ; distinguishing persons, ii. iio.
Parus aeruleus , ii. 174.
Passer , sexes and young of, ii. 212.
Passer brachydactytus , ii. 212.
Passer domcsticus, ii. 170, 212.
Passer mont anus, ii. 170,' 21 2.
Patagonians, self-saorilice by, i. 88.
Patters®, Mr., on the Aqrionidas,
i. 362. J
Pajiltstas of Brazil, i. 225.
J'avo cristatus, i. 290; ii. 136.
Pam rrmtiaus, i. 290, ii. 136; pos- session of spurs by the female, ii. 46, 162.
Pam niqripennis, ii. 120.
Payaguas Indians, thin legs and thick arms of the, i. 117.
Payan, Mr., on the proportion of the seres in sheep, i. 305.
Peacock, polygamous, i. 269 ; sexual characters of, i. 290 ; pugnacity of the, ii. 46 ; rattling of the quills by,
ii. 61 ; elongated tail-coverts of the, ii. 72, 97 ; love of display of the, ii. 135 ; 68, 87 ; ocellated spots of
454
PEACOCK.
INDEX.
PHEASANT.
the, ii. 135 ; inconvenience of long j tail of the, to the female, ii. 154, | 164, 165 ; continued increase of beauty of the, ii. 216.
Peacock-butterfly, i. 392.
Peafowl, preference of females for a particular male, ii. 120 ; first ad- vances made by the female, ii. 120.
Pediculi of domestic animals and man,
i. 219.
Pedigree of man, i. 213.
Pedionomus torquatas , sexes of, ii.
201.
Peewit, wing-tubercles of the male,
ii, 48.
Pelagic animals, transparency of, i. 323.
Pelecanus erythrorhynchus , horny crest on the beak of the male, during the breeding season, ii. 80.
Pelecanus onocrotalus , spring plumage of, ii. 85.
Pelele, ii. 341.
Pelican, blind, fed by his compa- nions, i. 77 ; young, guided by old birds, i, 77 ; pugnacity of the male, ii. 43.
Pelicans, fishing in concert, i. 75.
Pelobius Ilermanni. stridulation of, i. 380, 382.
Pelvis, alteration of, to suit the erect attitude of man, i. 143 ; differences of the, in the sexes in man, ii. 317.
Penelope nigra, sonnd produced by the male, ii. 64.
PENNANT, on the battles of seals, ii. 240; on the bladder-nose seal, ii. 278.
Penthe, antennal cushions of the male, i. 343.
Perch, brightness of male, during breeding season, ii. 13.
Peregrine Falcon, new mate found by, ii. 104.
Period of variability, relation of, to sexual selection, i. 296.
Periodicity, vital, Dr. Laycock on, i. 12.
Periods, lunar, followed by functions in man and animals, i. 12, 212.
Periods of life, inheritance at cor- responding, i. 280, 285.
Perisoreus canadensis, young of, n* 209.
Peritrichia , difference of colour in the sexes of a species of, i. 367.
Periwinkle, i. 324.
Pernis cristata, ii. 126.
Perseverance, a characteristic of man, ii. 328.
Persians, said to be improved by in- termixture with Georgians and Cir- cassian^ ii. 357.
Personnat, M., on Bombyx ¥amci~ mat , i. 310.
Peruvians, civilisation of the, not foreign, i. 183.
Petrels, colours of, ii. 230.
Petrocincla cyanea, young of, ii. 219.
Petronia , ii. 212.
Pfeiffer, Ida, on Javanese ideas of beauty, ii, 347.
Phacochccrus sathiopicus, tusks and pads of, ii. 265.
Piialanger, Vulpine, black varieties of the, ii. 294.
Phalaropus fulicarius, ii. 203.
Phalaropus hyperboreus , ii. 203.
Phanmus , i, 373.
Phanwus carnifex , variation of the horns of the male, i. 370.
Phan sens faunus, sexual differences of, i. 369.
Phanmus lancifcr , i. 370.
Phasqonura viridissima, stridulation of, i. 354, 356.
Phasianus Scemmerringit, ii. 157.
Phasianus versicolor , ii. 89.
Phasianus Wallichii, ii. 93, 196.
PuASMTiLE, mirnickrv of leaves by the, i. 414.
Pheasant, polygamous, i. 269 ; pro- duction of hybrids with the com- mon fowl, ii. 122 ; and black grouse, hybrids of, ii. 113 ; immature plumage of the, ii. 188.
Pheasant, Argus, ii. 72, 181; dis- play of plumage by the male, u* 91 ; ocellated spots of the, ii. 1^4, 141 ; gradation of characters the, ii. 141.
Pheasant, Blood-, ii. 46.
Pheasant, Cheer, ii. 93, 195.
Pheasant, Eared, i. 290; ii. 93, 19j’ sexes alike in the, ii. 178; lengt1 of the tail in the, ii. 166.
PHEASANT.
INDEX.
PLAIN.
455
Pheasant, Golden, display of plumage by the male, ii. 89 ; sex of young, ascertained by pulling out head- feathers, ii. 214; age of mature plumage in the, ii. 218.
Pheasant, Kalij, drumming of the male, ii. 62.
Pheasant, Reeve’s, length of the tail in, ii. 166.
Pheasant, Silver, sexual coloration of the, ii. 228 ; triumphant male, de- posed on account of spoiled plumage, ii. 120.
Pheasant, Sceramerring’s, ii. 156, 166.
Pheasant, Tragopan, ii. 72; display of plumage by the male, ii. 91 ; markings of the sexes of the, ii. 1 134.
Pheasants, period of acquisition of ■ male characters in the family of the, i. 290 ; proportion of sexes in chicks of, i. 306 ; length of the tail in, ii. 156, 164, 166.
Philodromus, i. 337.
Philters, worn by women, ii. 344. Phoca grcenlandica, sexual difference in the coloration of, ii. 287. Phrmicnra ruticilla, ii. 105. Phosphorescence of insects, i. 345. PiiKYGANiDAfi, copulation of distinct species of, i. 342.
Phnjniscus nigricans , ii. 25.
Physical inferiority, supposed, of man, i. 156.
Pickering, on the number of species of man, i. 226.
Picton, J. A., on the soul of man, ii.
395.
Picus auratus , ii. 43.
Pierid./E, mimiekry by female, i. 413. Pieris , i. 393.
Pigeon, carrier, late development of the wattle in, i. 293; domestic, breeds and subbreeds of, ii. 178; pouter, late development of the crop in, i. 293 ; female, deserting a weakened mate, i. 262.
Pigeons, nestling, fed by the secretion of the crop of both parents, i. 210; changes of plumage in, i. 281 ; transmission of sexual peculiarities in, i. 283 ; changing colour after se- veral moultings, i. 294 ; numerical
proportion of the sexes in, i. 306 ; cooing of, ii. 60; variations in plumage of, ii. 74; display of plu- mage by male, ii. 96 ; local memory of ii. 109; antipathy of female, to certain males, ii. 118; pairing of, ii. 118, 119; profligate male and female, ii. 119; wing-bars and tail- feathers of ii. 131; supposititious breed of, ii. 155 ; pouter and carrier, peculiarities of predominant in males, ii. 158; nidification of, ii. 168 ; im- mature plumage of the, ii. 188;. Australian, ii. 175; Belgian, with black-streaked males, i. 285, 293; ii. 157.
Pigs, origin of the improved breeds of,
i. 230 ; numerical proportion of the sexes in, i. 305; stripes of young, ii. 184, 303; sexual preference shown by, ii. 273.
Pike, American, brilliant colours of the male, during the breeding season, ii. 14.
Pike, male, devoured by females, i. 308.
Pike, L. 0,, on the psychical elements of religion, i. 68.
Pime/ia striata, sounds produced by the female, i, 385.
j Pintail Drake, plumage of, ii. 84; pairing with a wild duck, ii. 115. Pintail Duck, pairing with a Wigeon,
ii. 114.
Pipe-fish, filamentous, ii. 18; mar- supial receptacles of the male, ii. 21.
Pipits, moulting of the, ii. 83.
Pipra, modified secondary wing- feathers of male, ii. 65.
Pipra deliciosa , ii. 65, 66.
Pirates stridulus , stridulation ot, i. 350.
Pithecia Icucocephala , sexual differences of colour in, ii. 290.
Pithecia Satanas , beard of ii. 28o, 284, 285; resemblance of, to a
negro, ii. 381.
Pits, suborbital, of Ruminants, n, 280.
Pittidje, nidification of, ii. 167. Placentata, i, 202.
Plagiostomoits fishes, ii. 1. Plain-wanderer, Australian, ii. 201.
456
PLANARIZE.
INDEX.
PRE-EMINENCE.
Planariae , bright colours of some, i. 322.
Plantain-eaters, colours and nidi- fication of the, ii. 171; both sexes of, equally brilliant, ii. 177.
PLANT’S, cultivated, more fertile than wild, i. 132; Nageli, on natural selection in, i. 152 ; male flowers of, mature before the female, i. 260; phenomena of fertilisation in, i. 273; relation between number and size of seeds in, i. 317.
Platalea, ii. 60 ; change of plumage iu, ii. 179.
Phtyblemnus, i. 361.
Platycercus, young of, ii. 209.
Platyphyllmn concavmn, i. 352, 356.
Platyrriiine monkeys, i. 196.
Pj.atysma myoides, i. 19.
Plcmstomus, head-tentacles of the 1 male of a species of, ii. 10.
Plccostomus barbatus, peculiar beard of the male, ii. 10.
Plectroptnrus gambensis, spurred wings of, ii. 46.
Ploceus, ii. 54.
Plovers, wing-spurs of, ii. 48; double moult in, ii. 83.
Plumage, changes of, inheritance of, by fowls, i. 281 ; tendency to ana- lagons variation in, ii. 74’; display of, by male birds, ii. 86, 96 ; changes of, in relation to season, ii. 180; immature, of birds, ii. 183, 187 ; colour of, in relation to pro- tection, ii. 223.
Plumes on the head in birds, difference ! of, in the sexes, ii. 164.
Pneumora, structure of, i. 357.
Podica, sexual difl'eronco iu the colour of the iridcs of, ii, 128.
Poeppig, on the contact of civilised and savage races, i. 239,
Poison, avoidance of, by animals i 49.
Poisonous fruits and herbs avoided by animals, i. 36.
Poisons, immunity from, correlated with colour, i. 242.
Polish fowls, origin of the crest in, i. 284.
Pollen and van Dam, on the colours of Lemur macaco, ii. 290.
Polyandry, ii. 365 ; in certain
cyprinidaj, i. 309 ; among the ela- tcridie, i. 313.
Polydactylisii in man, i. 125.
Polygamy, influence of, upon sexual .select ion, i. 265 ; superinduced by domestication, i. 270; supposed increase of female births by, i. 303 ; in the stickleback, ii. 2.
Poly gen ists, i. 228.
Polynesia, prevalence of infanticide in, ii. 364.
Polynesians, aversion of, to hairs on the face, ii. 349 ; wide geographical range of, i. 112; diUiirenee of stature among the, i. 115; crosses of, 1. 225 ; variability of, i. 225; heterogeneity of the, i. 241.
Polyplectron , display of plumage by the male, i. 89 ; number of spurs iu, ii. 46 ; gradation of characters in, ii. 137 ; female of, ii. 194.
Polyplectron ckinquis, ii. 90, 138, 139.
Polyplectron Hardwicliii, ii. 138, 139.
Polyplectron malar.cense, ii. 139, 140.
Polyplectron Napoleonic, ii. 138, 140.
Polvzoa, i, 324.
Pontoporeia affinis, i. 329.
Porcupine, mute, except in the rut- ting season, ii. 274.
Pores, excretory, numerical relation of, to the hairs in sheep, i. 248.
Porpitm, bright colours of some, i- 322.
Portax picta, dorsal crest and throat- tuft of, ii. 282 ; sexnal differences of colour in, ii. 287, 299.
Portunus puber, pugnacity of, i. 332.
Potamochoerus penicillatus, tusks and facial knobs of the, ii. 206.
PouctiET, G., on the ratio of instinct and intelligence, i. 37 ; on the in- stincts of ants, i. 187; on the caves of Abou-Simhei, i. 217 ; on the im- munity of negroes from yellow' fever, i. 243,
Pouter pigeon, late development of the large crop in, i. 293.
Power, Dr., on the different colours of the sexes in a species of SquillQi i. 335.
Powys, Mr., on the habits of the chaffinch in Corfu, i. 307.
Pre-eminence of man, i. 137.
PREFERENCE,
INDEX.
QUATREFAGES.
457
Preference for males by female ! birds, ii. 113, 122 ; shown by mam- mals, in pairing, ii. 268.
Prehensile organs, i. 256.
Presbytis enieflus, fighting of the male, ii. 324.
Preyer, Dr., on supernumerary mam- ma in women, i. 125.
Prichard, on the difference of stature among the Polynesians, i. 115 ; on the connection between the breadth of the skull in the Mongolians and the perfection of their senses, i. 119; on the capacity of British skulls of different ages, i. 146 ; on the flattened heads of the Colombian savages, ii. 340; on Siamese notions ! of beauty, ii. 345 ; on the beard- lessness of the Siamese, ii. 349; on 1 the deformation of the head among I American tribes and the natives of Arakhan, ii. 352.
Primary sexual organs, i. 254.
Primates, i. 190 ; sexual differences of colour in, ii. 290.
Primogeniture, evils of, i. 170.
Primula , relation between number and size of seeds in, i. 317.
Prionid^e, difference of the sexes in colour, i. 367.
Proctotretus multiimculatus , ii. 26, 37.
Pt'octotretus tenuis , sexual difference in the colour of, ii. 37.
Profligacy, i. 173.
Progenitors, early, of man, i. 206.
Progress, not the normal rule in human society, i. 166 ; elements of, i. 177.
Prong-horn, horns of, i. 289.
Proportions, difference of, in distinct races, i. 216.
Protective colouring in butterflies,
i. 392; in lizards, ii. 37 ; in birds,
ii. 197, 223; in mammals, ii. 298, 299.
Protective nature of the dull colour- ing of female Lepidoptera, i. 403, 405, 414.
Protective resemblances in Ashes, ii. 18.
Protozoa, absence of secondary sex- ual characters in, i. 321.
Pruner-Bey, on the occurrence of
the supra-condyloid foramen in the humerus of man, i. 29 ; on the colour of negro infants, ii. 31&.
Prussia, numerical proportion of male and female births in, i. 301.
Psocus , proportions of the sexes in, i. 314.
Ptarmigan, monogamous, i. 269 ; summer and winter plumage of the, ii. 81, 83 ; nuptial assemblages of, ii. 101 ; triple moult of the, ii. 181 ; protective coloration of, ii. 198.
Puff-birds, colours and nidification of the, ii. 171.
Pugnacity of fine-plumaged male birds, ii. 93.
Pumas, stripes of young, ii. 183.
Puppies learning from cats to clean their faces, i. 44.
Pyomnotus hmmorrhous , pugnacity of the male, ii. 41 ; display of under tail coverts by the male, ii. 96.
Pyranya gsttiva, male aiding in incu- bation, ii. 167.
Pyrodcs, difference of the sexes in colour, i, 367.
Q.
Quadrumana, hands of, i. 139; dif- ferences between man and the, i. 190 ; dependence of, on climate, i. 218; sexual differenced of colour li* ’ ornamental characters of, ii. 306 ; analogy of sexual dif- ferences o{, with those of man, ii. 318; fighting of males for the females, ii, 324; monogamous habits of, ii. 361 ; beards of the, ii. 378.
Quain, R., on the variation of the muscles in man, i. 109.
Quatrefages, A. de, on the occur- rence of a rudimentary tail in man, i. 29 ; on the moral sense as a dis- tinction between man and animals, i. 70; on variability, i. 112; on the fertility of Australian women with white men, i. 221 ; on the Paulistas of Brazil, i. 225 ; on the evolution of the breeds of cattle, i. 230 ; on the Jews, i. 242 ; on the liability of negroes to tropical fevers
458
QUECIIUA.
INDEX.
REINDEER.
after residence in a cold climate, i. 243 ; on the difference between field- and house-slaves, i. 246 ; on the influence of climate on colour, i. 246; on the Ainos, ii. 321; on the women of San Giuliano. ii. 357.
Quechua Indians, i. 119 ; local varia- tion of colour in the, i. 246 ; no grey hair among the, ii. 320 ; hair- lessness of the, ii. 322 ; long hair of the, ii. 348.
Querquedula acuta , ii. 114.
Quiscalus major , proportions of the sexes of, in Florida and Honduras, i. 307.
K.
Rabbit, white tail of the, ii. 298.
Rabbits, danger-signals of, i. 74; domestic, elongation of the skull in, i. 147 ; modification of the skull in, by the lopping of the ear, i. 147 ; numerical proportion of the sexes in, i. 305.
Races, distinctive characters of, i. 215 ; or species of man, i. 217 ; crossed, fertility or sterility of, i. 220 ; of man, variability of the, i. 225 ; of man, resemblance of, in mental characters, i. 232 ; forma- tion of, i. 235 ; of man, extinction of, i. 236; effects of the crossing of, i. 240; of man, formation of the, i. 240 ; of man, children of the, ii. 318 ; beardless, aversion of, to hairs on the face, ii. 349.
Raffles, Sir S., on the Bantcng, ii. 290.
Rafts, use of, i. 137, 234.
Rage, manifested by animals, i. 40.
Raia batis , teeth of, ii. 6.
Raia clavata , female spined on the back, ii. 2 ; sexual difference in the teeth of, ii. 6.
Uaia maculatn, teeth of, ii. 6.
Rails, spur- winged, ii. 48.
Ram, mode of fighting of the, ii. 249; African, mane of an, ii. 284 ; fat- tailed, ii. 284.
Rameses II., i. 217.
Ramsay, Mr., on the Australian Musk-duck, ii. 38 ; on the Regent-
bird, ii. 113; on the incubation of Menura superba , ii. 165.
Rana esculenta , vocal sacs of, ii. 28.
Rat, common, general dispersion of, a consequence of superior cunning, i. 50; supplautation of the native, in New Zealand, by the European rat, i. 240 ; common, said to be polygamous, i. 268 ; numerical pro- portion of the sexes in, i. 305.
Rats, enticed by essential oils, ii* 281.
Rationality of birds, ii. 108.
Rattle-snakes, difference of the sexes in the, ii. 29 ; said to use their rattles as a sexual call, ii* 30.
Raven, vocal organs of the, ii. 55 ; stealing bright objects, ii. 112; pied, of the Fcroe Islands, ii. 126.
Rays, prehensile organs of male, ii. 1*
Razor-bill, young of the, ii. 217.
Readg, Winwood, on the Guinea sheep, i. 289; non-development oi horns in castrated male Guinea sheep, ii. 247 ; on the occurrence ot a mane in an African ram, ii. 285 ; on the negroes’ appreciation of the beauty of their women, ii. 344; on the admiration of negroes for a black skin, ii. 346 ; on the idea of beauty among negroes, ii. 350 ; on the Jollofs, ii. 357 ; on the mar- riage-customs of the negroes, ii* 374.
Reason, in animals, i. 46.
Redstart, American, breeding in im- mature plumage, ii. 214.
Redstarts, new mates found by, ii* 105.
REDUviDiE, stridulation of, i. 350.
Reed-bunting, head-feathers of the male, ii. 95; attacked by a bull- finch, ii. 111.
Reefs, fishes frequenting, ii. 17.
Regeneration, partial, of lost parts in man, i. 13.
Regent-bird, ii. 112.
Reindeer, antlers of, with numerous points, ii. 252 ; sexual preferences shown by, ii. 273; horns of the, i* 288 ; winter change of the, ii* 299 , battles of, ii. 240; horns of the female, ii. 243.
RELATIONSHIP.
INDEX.
ROBERTSON.
459
Relationship, terms of, ii. 360.
Religion, deficiency of, among cer- tain races, i. 65 ; psychical elements of, i. 68.
Remorse, i. 91 ; deficiency of, among savages, i. 164.
Rengger, on the diseases of Cebus Azarse, i. 1 1 ; on maternal affection in a Cebus, i. 40 ; revenge taken by monkeys, i. 40 ; on the reasoning powers of American monkeys, i. 47 ; on the use of stones by mon- keys for cracking hard nuts, i. 51; on the sounds uttered by Cebus Azarse, i. 54; on the signal-cries of monkeys, i. 57 ; on the diversity of the mental faculties of monkeys, i. 110; on the Payaguas Indians, i. 117 ; on the inferiority of Eu- ropeans to savages in their senses, i. 118 ; on the polygamous habits of Mycetes ceiraya, i. 266 ; on the voice of the howling monkeys, ii. 277 ; on the odour of Cervus cam - pestris , ii. 279 ; on the beards of Mycetes caraya and Pitheda Sabi- nas, ii. 283 ; on the colours of Falls rnitis , ii. 287 ; on the colours of Cervus paludosus , ii. 290 ; on sexual differences of colour in Mycetes , ii. 291 ; on the colour of the infant Guaranys, ii. 318 ; on the early maturity of the female of Cebus azarse, ii. 318; on the beards of the Guaranys, ii. 322, 323 ; on the emotional notes employed by mon- keys, ii. 336 ; on American polyga- mous monkeys, ii. 362.
Representative species, of birds, ii. 190, 191.
Reproduction, unity of phenomena of, throughout the mammalia, i. 13; period of, in birds, ii. 214.
Reproductive system, rudimentary structures in the, i. 30 ; accessory parts of, i. 207.
Reptiles, ii. 28.
Reptiles and birds, alliance of, i. 213.
Resemblances, small, between man and the apes, i. 191.
Retrievers, exercise of reasoning faculties by, i. 48.
Revenge, manifested by animals, i. 40.
Reversion, i. 122 ; perhaps the cause of some bad dispositions, i. 173.
Bhagium, difference of colour in the sexes of a species of, i. 367.
Rhamphastos carinatus , ii. 227.
Rhinoceros, nakedness of, i. 148; horns of, ii. 247 ; horns of, used de- fensively, ii. 263 ; attacking white or grey horses, ii. 295.
Bhynchsea, sexes and young of, ii.
202.
Bhynchsea australis, ii. 203.
Bhynchsea bengalensis, ii. 203.
Bhynchsea capensis, ii. 202.
Rhythm, perception of, by animals, ii. 333.
Richard, M., on rudimentary mus- cles in man, i. 19,
Richardson, Sir J., on the pairing of Tetrao umbeilus, ii. 49 ; on Tetrao urophasianus , ii. 58 ; on the drum- ming of grouse, ii. 63; on the dances of Tetrao phasianellus , ii. 69; on assemblages of grouse, ii. 101 ; on the battles of male deer, ii. 240 ; on the reindeer, fi. 244 ; on the horns of the musk-ox, ii. 247 ; on antlers of the reindeer with numerous points, ii. 252 ; on the moose, ii. 259.
Richardson, on the Scotch deer- hound, ii. 261.
Richter, Jean Paul, on imagination,
i. 45.
Riedel, on profligate female pigeons,
ii. 119.
Ring-ouzel, colours and nidification of the, ii. 170.
Rip a, Father, on the difficulty of distinguishing the races of the Chinese, i. 215.
Rivalry, in singing, between male birds, ii. 53.
River-hog, African, tusks and knobs of the, ii. 266.
RrvERS, analogy of, to islands, i. 204.
Roach, brightness of male during breeding-season, ii. 13.
Robbery, of strangers, considered honourable, i. 94.
Robertson, Mr., remarks on the development of the horns in the roebuck and red-deer, i. 288.
460
ROBIN.
INDEX.
SANDWICH.
Robin, pugnacity of the male, ii. 40 ; autumn song of the, ii. 54 ; female, singing of the, ii. 54; attacking other birds with red in their plu- mage, ii. Ill * young of the, ii.
208.
Robinet, on the difference of size of the male and female cocoons of the silk-moth, i. 346.
Rodents, uterus in the, i. 123 ; ab- sence of secondary sexual characters in, i. 268 ; sexual differences in the colours of, ii. 286.
Roe, winter change of the, ii. 209.
Kolle, F., on the origin of man, i. 4; on a change in German families settled in Georgia, i. 246.
Roller, ii. 5G.
Romans, ancient, gladiatorial exhi- bitions of the, i. 101.
Rook, voice of the, ii. 61.
RoSSLER, Dr., on the resemblance of the lower surface of butterflies to the bark of trees, i. 392,
Rostrum, sexual difference in the length of, in some weevils, i. 255.
Rudimentary organs, 4. 17 : origin
of, i. S2,
Rudiments, presence of, in languages,
Rudolphi, on the want of connexion between climate and the colour of the skin, i. 241.
Ruff, supposed to be polygamous, i. 2i0; proportion of the sexes in the, i. 306 ; pugnacity of the, ii. 41, 48; double moult in, ii. 81, 84; duration of dances of, ii. 100; attraction of the, to bright objects, ii. 111.
Ruminants, male, disappearance of canine teeth in, i. 144, ii. 325; ge- nerally polygamous, i. 266 ; analogy of Lamellicorn beetles to, i. 373 • suborbital pits of, ii. 280; sexual differences of colour in, ii. 287.
liupicola crocea , display of plumage by the male, ii. 87.
Rupee U., on canine teeth in deer and antelopes, ii. 258,
Russia, numerical proportion of male and female births in, i. 301.
Buticilla , ii. 180.
Rutimeyer, Prof., on the physiogno-
my of the apes, i. 149; on the sexual differences of monkeys, ii* 323.
Rutlandshire, numerical proportion of male and female births in, i* 301.
S.
SAcns, Prof., on the behaviour of the nitile and female elements in fertili- sation, i, 274.
Sacrifices, Human, i. 182.
Sagittal crest in male apes and Australians, ii. 319.
Sahara, birds of the, ii. 172 ; animal inhabitants of the, ii. 224.
Sailors, growth of, delayed by con- ditions of life, i. 114; long-sighted, i. 118.
Sailors and soldiers, difference in the proportions of, i. 116.
ST. John, Mr., on the attachment of mated birds, ii. 108.
St. Kilda, beards of the inhabitants of, ii. 321.
Salmo eriox, and S. umbla , colouring of the male, during the breeding season, ii. 14.
Salmo lyouodon , ii. 4.
Salmo salary ii. 4.
Salmon, leaping out of fresh water, i. 83 ; male, ready to breed before the female, i. 260 ; proportion of the sexes in, i. 308 ; male, pugna- city of the, ii. 3 ; male, characters of, during the breeding season, h* 3, 14; spawning of the, ii. » breeding of immature male, n‘ 215.
S alvin, O., on the Humming-birds, i* 269, ii. 168; on the numerical proportion of the sexes in Hum- ming-birds, i. 307, ii. 221; on Cha- mxpetes and Penelope, ii. 64; oD Selasphorus platycercus, ii. 65 ; °n Pipra deliciosa , ii. 66 ; on Chasm0' rhynchus, ii. 79.
Samoa Islands, beardlessness of f'ie natives of, ii. 322, 349.
Sand-skipper, i. 334.
Sandwich Islands, variation in toe skulls of the natives of the, i. ’
SANDWICH.
INDEX.
SCOLOPAX.
461
superiority of the nobles in the, ii. 356.
Sandwich Islanders, lice of, i. 219.
San-Giuliano, women of, ii. 357.
Saxtali, recent rapid increase of the, i. 133 ; Mr. Hunter on the, i. 241.
Saphirina , characters of the males of, i. 335.
Sarkidiornis mdanonotust characters of the young, ii. 185.
Saks, 0., on Pontoporeia offinis , i. 329.
Saturnia. carpini , attraction of males by the female, i. 311.
Saiumia Io , difference of coloration in the sexes of, i. 398.
Saturniidie , coloration of the, i. 396, 398.
Savage, Dr., on the fighting of the , male gorillas, ii. 324 ; on the habits ! of the gorilla, ii, 363.
Savage and Wyman, on the poly- gamous habits of the gorilla, i. 266.
Savages, imitative faculties of, i. 57, 161 ; causes of low morality of, i. 97 ; uniformity of, exaggerated, i. Ill; long-sighted, i. 118; rate of increase among, usually small, i. 132; retention of the prehensile power of the feet by, i. 142 ; tribes of, supplanting one another, i. 160; improvements in the arts among,
i. 182; arts of, i. 234; fondness of, for rough music, ii. 67 ; atten- tion paid by, to personal appearance,
ii. 338; relation of the sexes among, ii. 363.
Saw-fly, pugnacity of a male, i. 364.
Saw-flies, proportions of the sexes in, i. 314.
Saxicola rubicola, young of, ii. 220.
Scalp, motion of the, i. 20.
Scent-glands in snakes, ii. 30.
Schaaffhauskn, Prof., on the de- velopment of the posterior molars in different races of man, i. 26 ; on the jaw from La Naulette, i. 126 ; on the correlation between muscularity and prominent supra-orbital ridges, i. 130 ; on the mastoid processes of man, i. 143 ; on modifications of
the cranial bones, i. 147 ; on human sacrifices, i. 182 ; on the probable speedy extermination of the anthro- pomorphous apes, i. 201 ; on the ancient inhabitants of Europe, i. 237 ; on the effects of use and dis- use of parts, i. 247 ; on the super- ciliary ridge in man, ii. 316 ; on the absence of race-differences in the infant skull in man, ii. 318 ; on ugliness, ii. 354.
Scjiauji, H., on the elytra of Dytiscus and Ifydroporus , i. 343.
Sen elver, on dragon-flies, i. 363.
Schiodte, on the stridulation of llete- ruoerus , i. 379.
SciTLKGKL, F. von, on the complexity of the languages of uncivilized peo- ples, i. 61.
Sciilegel, Prof., on Tanysiptera, ii.
1 90#
Schleicher, Prof., on the origin of language, i. 56.
Schleiden, Prof., on the rattle-snake, ii. 30.
Schombitrgk, Sir R., on the pugnacity of the male musk-duck of Guiana, ii. 43; on the courtship of Pupi- cola vrocea , ii. 87.
Schoolcraft, Mr., on the difficulty of fashioning stone implements, i. 138.
Sclater, P. L., on modified secondary wing-feathers in the males of Pipra, ii. 65 ; on elongated feathers in nightjars, ii. 73; on the species of Chasmorhynchus, ii. 79 ; on the plumage of Pelccanus onocrotatus, ii. 85; on the plantain-eaters, ii. 177 ; on the sexes and young of Tadorm variegata , ii. 206; on the colours of Lemur macaco, ii- 290 ; on the stripes in asses, ii. 305.
Scolecida, absence of secondary sex- ual characters in, i. 321.
Scolopax fremta, tail-feathers of, ii. 64.
Scolopax gallinagoy drumming of, ii.
63.
Scolopax javensis , tail-feathers of, ii.
64.
Scolopax major , assemblies of, ii. 101.
Scolopax Wilsonii , sound produced by,
ii. 64.
462
SCOLYTUS.
INDEX.
SEXUAL.
Scolytus , stridulation of, i. 379.
Scoter-duck, black, sexual difference in coloration of the, ii. 226; bright beak of male, ii. 227.
Scott, J., on the colour of the beard in man, ii. 319.
Scrope, on the pugnacity of the male salmon, ii. 3; on the battles of stags, ii. 240.
Scudder, S. H., imitation of the stridulation of the Orthoptera, i. 353 ; on the stridulation of the Acridiidx , i. 356 ; on a Devonian insect, i. 360; on stridulation, ii. 331.
Sculpture, expression of the ideal of beauty by, ii. 350.
Sea-anemonies, bright colours of, i. 322,
Sea-bear, polygamous, i. 268.
Sea-elephant, male, structure of the nose of the, ii. 278 ; polyga- mous, i. 268.
Sea-lion, polygamous, i. 268.
Seal, bladder-nose, ii. 278.
Seals, their sentinels generally fe- males, i. 74; evidence furnished by, on classification, i. 190; sexual dif- ferences in the coloration of, ii. 287; appreciation of music by, ii. 333 ; battles of male, ii. 240 ; ca- nine teeth of male, ii. 241 ; poly- gamous habits of, i. 268; pairing j of, ii. 269 ; sexual peculiarities of, ' ii. 277.
Sea-scorpion, sexual differences in, ii. 9.
Season, changes of colour in birds, in accordance with the, ii. 80 ; changes of plumage of birds iu relation to, ii. 180.
Seasons, inheritance at correspond- ing, i. 282.
Sebituani, ii. 340.
Sebright Bantam, i. 294.
Secondary sexual characters, i. 253 ; relations of polygamy to, i. 266 ; gradation of, in birds, ii. 135 ; transmitted through both sexes, i. 279.
Sedgwick, W., on hereditary ten- dency to produce twins, i. 133.
Seemann, Dr., on the different appre- ciation of music by different peo-
ples, ii. 334; on the effects of music, ii. 335.
Selasphonts platycercus, acuminate first primary of the male, ii. 65.
Selby, P, J., on the habits of the black and red grouse, i. 269.
Selection, double, i. 276.
Selection of male by female birds*
I ii. 99, 122.
Selection, methodical, of Prussian grenadiers, i. 112.
Selection, sexual, influence of, on the colouring of Lepidoptera, x* 403 ; explanation of, i. 256, 260, 271.
Selection, sexual and natural, con- trasted, i. 278.
Self-command, habit of, inherited,
i. 92 ; estimation of, i. 95.
Self-consciousness, i. 62.
Self-preservation, instinct of, *•
89.
Self-sacrifice, by savages, i. 88; estimation of, i. 95.
Semilunar fold, i. 23.
Scmnopithecus , i. 197 ; long hair on the heads of species of, i. 192 ; n- 380.
Semnopithccus chrysomelas , sexual dif' ferences of colour in ii. 291.
Semnopithccus comatus , ornamental hair on the head of, ii. 307.
Semnopithccus f contains, beard, of, ii. 308.
Scmnopithecus nasica , nose of, l# 192.
Semnopithccus ncmmus, colouring
ii. 310.
Scmnopithecus rubicundus , ornamen- tal hair on the head of, ii. 306.
Senses, inferiority of Europeans savages in the, i. 1 18.
Sentinels, i. 74, 82.
Serpents, instinctively dreaded by apes and monkeys, i. 37, 42.
Seer anus, hermaphroditism in i- 205-
Sex, inheritance limited by, i. 282-
Sexes, relative proportions of, 1 man, i. 300, ii. 320 ; probable r0' lation of the, in primeval man* * 362.
Sexual characters, secondary, i- ’ relations of polygamy to, i- - ’
transmitted through both se*e ,
SEXUAL.
INDEX.
SLAVERY.
463
i. 279; gradation of, in birds, ii. 135.
Sexual and natural selection, con- trasted, i. 278.
Sexual characters, effects of the loss of, i. 284 ; limitation of, i. 284.
Sexual differences in man, i. 14.
Sexual selection, explanation of, i. 256, 260, 271 ; influence of, on the colouring of Lepidoptera, i. 403 : action of, in mankind, ii. 368.
Sexual similarity, i. 277.
Sharks, prehensile organs of male, |i. 1.
Sharpe, R. B., on Tanysipfera sylvia ,
ii. 165; on Ceryte , ii. 173; on the young male of Dacelo GaudichaudL ii. 188.
Shaw, Mr., on the pugnacity of the male salmon, ii. 3.
Shaw, J., on the decorations of birds, ii. 71.
Sheep, danger-signals of, i. 74 ; sex- ual differences in the horns of, i. 283 ; horns of, i. 289, ii. 246, 259 ; domestic, sexual differences of, late developed, i. 293; numerical pro- portion of the sexes in, i. 304 ; mode of fighting of, ii. 249; arched foreheads of some, ii. 284.
Sheep, Merino, loss of horns in fe- males of, i, 284 ; horns of, i. 289.
Shells, difference in form of, in male and female Gasteropoda, i. 324 ; beautiful colours and shapes of, i. 326.
Shield-drake, pairing with a com- mon duck, ii. 114; New Zealand, sexes and young of, ii. 206.
Shooter, J., on the Kaffirs, ii. 347 ; on the marriage - customs of the Kaffirs, ii. 373.
Shrew-mice, odour of, ii. 279.
Shrike, Drongo, ii. 179.
Shrikes, characters of young, ii. 185.
Shuckard, YV. E., on sexual differ- ences in the wings of Hymenoptera, i. 435.
Shyness of adorned male birds, ii. 97.
Siagonium , proportions of the sexes in, i. 314 ; dimorphism in males of, i. 374.
Siam, proportion of male and female births in, i. 303.
Siamese, general beardlessness of the, ii. 321 ; notions of beauty of the, ii. 345 ; hairy family of, ii. 378.
Sikbold, C. T. von, on the auditory apparatus of the stridulant ortho- ptera, i. 353.
Sight, inheritance of long and short, i. 118.
Signal-cries of monkeys, i. 57.
Silk-moth, difference of size of the male and female cocoons of the, i. 346; pairing of the, i. 401 ; male, fer- tilising two or three females, i. 406 ; proportion of the sexes in, i. 309, 311; Ailanthus, Prof. Oanestrini, on the destruction of its larva* by wasps, i. 311.
Simiaile, i. 195; their origin and divisions, i. 213.
Similarity, sexual, i. 277.
Singing of theCicadie and Fulgoridaj, i. 351 ; of tree-frogs, ii. 27 ; of birds, object of the, ii. 52.
Sirenia, nakedness of, i. 148.
Strcx juvencus, i. 365.
SiRiciDiE, difference of the sexes in
i. 365.
Siskin, ii. 85 ; pairing with a canary,
ii. 115,
Sitana, throat-pouch of the males of ii. 33, 36.
Size, relative, of the sexes of insects,
i. 345.
Skin, movement of the, i. 19 ; naked- ness of, in man, i, 148 ; colour of the, i. 241.
Skin and hair, correlation of colour of, i. 248.
Skull, variation of, in man, i. 108; cubic contents of, no absolute test ot intellect, i. 145; Neanderthal, capacity of the, i. 146; causes of modification of the, i. 147 ; differ- ence of, in form and capacity, in different races of men, i. 216 ; vari- ability uf the shape of the, i. 226 ; difference* of, in the sexes in man,
ii. 317 ; artificial modifications of the shape of, ii. 340.
Skunk, odour emitted by the, ii. 279.
Slavery, prevalence of, i. 94; of women, ii. 366.
4G4
SLAVES.
INDEX.
SPECIES.
Slaves, difference between those of field and house, i. 246.
Smell, sense of, in man and animals, i. 23.
Smith, Adam, on the basis of sym- pathy, i. 82.
Smith, .Sir A., on the recognition of women by male Cynocephali , i. 13; on an instance of memory in a baboon, i. 45 ; on the retention of their colour by the Dutch in South Africa, i. 242 ; on the polygamy of the South African antelopes, i. 267 ; on the proportion of the sexes in Kobus ellipsiprymnus , i. 305 ; on Bucephalus capensis, ii. 29 ; on South African lizards, ii, * 37 ; on , fighting gnus, ii. 240 ; on the horns | of rhinoceroses, ii. 248; on the fighting of lions, ii. 266; on the colours of the Cape Eland, ii. 288 ; on the colours of the gnu, ii. 289 ; on Hottentot notions of beauty, ii. 345.
Smith, on the Cynipid® and Ten- thredinidaj, i. 314; on the relative size of the sexes of Aculeate Hyme- noptera, i. 347 ; on the difference bet ween the sexes of ants and bees, I
i. 365 ; on the stridulation of Trox sabulosus, i. 380; on the stri- [
'382^011 °*' ^onmyc^U8 Pseu^a<^rh
Smyuthurus luteus, courtship of, i. 348. r
Snakes, sexual differences of, ii. 29 ; male, ardency of, ii. 30.
“ Snarling muscles,” i. 127.
Snipe, drumming of the, ii. 63 ; colo- ration of the, ii. 226.
Snipe, painted, sexes and young of
ii. 202.
Snipe, solitaiy, assemblies of, ii, 101.
Snipes, arrival of male before the female, i. 260 ; pugnacity of male, ii. 43 ; double moult in, ii. 80.
Snow-goose, whiteness of the, ii. 228.
Social animals, affection of, for each other, i. 76 ; defence of, by the males, i. 83.
Sociability-, the sense of duty con- nected with, i. 71 ; impulse to, in
animals, i. 79, 80 ; manifestations of, in man, i. 84 ; instinct of, io animals, i. 86.
Sociality-, probable, of primeval men, i. 155; influence of, on the development of the intellectual faculties, i. 160 ; origin of, in man,
i. 161.
Soldiers, American, measurements of, i. I 1 4.
Soldiers and sailors, difference in the proportions of, i. 116.
fiolenoxtoma, bright colours and mar- supial sack of the females of, ii* 22.
Song of male birds appreciated by their females, i. 63 ; want of, in brilliant plumaged birds, ii. 94 ; of birds, ii. 163.
Sorex, odour of, ii. 279.
Sounds admired alike by man and animals, i. 64; produced by fishes,
ii. 23 ; produced by male frogs and toads, ii. 27 ; instrumen tally pro- duced by birds, ii. 63 et seqq.
Spain, decadence of, i. 178.
Sparassus smaragduhu? , difference of colour in the sexes of, i, 337, 338.
Sparrow, pugnacity of the male, ii. 40 ; acquisition of the Linnet's song by a, ii. 55 ; coloration of the. ii. 198; immature plumage of tl e, ii. 188.
Sparrow, white-crowned, young the, ii. 217.
Sparrows, house- and tree-, ii. 170. j Sparrows, new mates found by, ii*
| 105.
j Sparrows, sexes and young of, ii* 212; learning to sing, ii. 334.
, Spatkura Ohderwoodi , ii. 77.
| Spawning of fishes, ii. 15, 19.
Spear, origin of the, i. 234.
Species, causes of the advancement of, i. 172; distinctive characters of, i. 214 ; or races of man, i. 217 » sterility and fertility of, when crossed, i. 122 ; supposed, of m»n» i. 226 ; gradation of, i. 227 ; diffi- culty of defining, i. 228 ; repre- sentative, of birds, ii. 190, 191 ; of birds, comparative differences between the sexes of distinct, 11 • 192.
SPECTRE.
INDEX.
STAUDINGER.
465
Spectre-insects, mimickry of leaves by, i. 414.
Spectrum femoratum , difference of colour in the sexes of, i. 361.
Speech, connection between the brain and the faculty of, i. 58.
“ Spkl ” of the black-cock, ii. 60.
Spencer, Herbert, on the dawn of intelligence, i. 37 ; on the origin of the belief in spiritual agencies, i. 66 ; on the origin of the moral sense, i. 101 ; on the influence of food on the size of the jaws, i. 118 ; on the ratio between individuation and genesis, i. 318 ; on music, ii. 336.
Sperm-whales, battles of male, ii. 240.
Sphingidas, coloration of the, i. 396.
Sphinx, Humming-bird, i. 399.
Sphinx , Mr. Bates on the caterpillar of a, i. 416.
Spiders, i. 337 ; male, more active than female, i, 272 ; proportion of the sexes in i. 314; male, small size of, i. 338.
Spilosoma 7nenthmsti, rejected by turkeys, i. 398.
Spine, alteration of, to suit the erect attitude of man, i. 143.
Spirits, fondness of monkeys for, i. 12.
Spiritual agencies, belief in, almost universal, i. 65.
Spoonbill, ii. 60 ; Chinese, change of plumage in, ii. 179.
Spots, retained throughout groups of birds, ii 131 ; disappearance of, in adult mammals, ii. 303.
Sprengel, C. K., on the sexuality of ! plants, i. 260.
Spring-boc, horns of the, ii. 251.
Sproat, Mr., on the extinction of savages in Vancouver Island, i. 239 ; on the eradication of facial hair by the natives of Vancouver Island, ii. 348; on the eradication of the beard by the Indians of Van- couver Island, ii. 380.
Spurs, occurrence of, in female fowls, i. 280, 284; development of, in various species of Phasianidas, i. 290 ; of Gallinaceous birds, ii. 44,
46 ; development of, in female Gal- linaceas, ii. 162.
VOL. II.
Squilla , different colours of the sexes of a species of, i. 335.
Squirrels, battles of male, ii. 239 ; African, sexual differences in the colouring of, ii. 286 ; black, ii. 294. Stag, long hairs of the throat of, ii. 268; horns of the, i. 279, 282; battles of, ii. 240; horus of the, with numerous branches, ii. 252 ; bellowing of the, ii. 274; crest of the, ii. 282.
Stag-beetle, large size of male, i. 347 ; weapons of the male, i. 375; numerical proportion of sexes of, i. 313.
Stainton, H, T., on the numerical proportion of the sexes in the smaller moths, i. 310; habits of JJlachista rufocinerea , i. 311 ; on the coloration of moths, i. 397 ; on the rejection of Spilosoma men- thrasti, by turkeys, i. 398 ; on the sexes of Agt'otis exdamationis , i. 399.
Stallion, mane of the, ii. 268. Stallions, two, attacking a third, i. 75 ; fighting, ii. 241 ; small canine teeth of, ii. 258.
Stansburv, Capt., observations on pelicans, i. 77.
Stapiiylinid^e, hornlike processes in male, i. 374.
Starfishes, bright colours of some, i. 322.
Stark, Dr., on the death-rate in towns and rural districts, i. 175 ; on the influence of marriage on mortality, i. 176; on the higher mortality of males in Scotland, i. 302.
Starling, American field, pugnacity of male, ii. 51.
Starling, red-winged, selection of a mate by the female, ii. 1 1 6. Starlings, three, frequenting the same nest, i. 269, ii. 106 ; new mates found by, ii. 105.
Statues, Greek, Egyptian, Assyrian, &e., contrasted, ii. 350.
Stature, dependence of, upon local influences, i. 114.
Staudinger, Dr., his list of Lepido- ptera, i. 312 ; on breeding Lepido- ptera, i. 311.
2 H
466
STAUNTON.
INDEX.
SWINHOE.
Staunton, Sir G., hatred of indecency a modern virtue, i. 96.
Stealing- of bright objects by birds, ii. 112.
Stebbing, T. R., on the nakedness of the human body, ii. 375.
Stemmatopus , ii. 278.
Stenobothrus pratorum , stridulating organs of, i. 357.
Sterility, general, of sole daughters,
i. 170 ; when crossed, a distinctive character of species, i. 214.
Sterna, seasonal change of plumage in,
ii. 228.
Stickle-back, polygamous, i. 271; male, courtship of the, ii. 2 ; male, brilliant colouring of, during the breeding season, ii. 14; nidification of the, ii. 20.
STICKS used as implements and wea- pons by monkeys, i. 51.
Sting in bees, i. 254.
Stokes, Capt., on the habits of the great Bower-bird, ii. 70.
Stonechat, young of the, ii. 220.
Stone implements, difficulty of making, i. 138 ; as traces of extinct tribes, i. 237.
Stones, used by monkeys for break- ing hard fruits and as missiles, i. 140 ; piles of, i. 233.
Stork, black, sexual differences in the bronchi of the, ii. 60 ; red beak of the, ii. 227.
Storks, ii. 226, 230 ; sexual differ- ence in the colour of the eyes of, ii. 128.
Strange, Mr., on the Satin Bower- bird, ii. 69.
Stretch, Mr., on the numerical pro- portion in the sexes of chickens, i. 306.
Strcpsiceros kudu, horns of, ii. 255; markings of, ii. 300.
StridulatioN, by males of Theridion , i. 339; of the Orthoptera and Ilomoptera discussed, i. 360 ; of beetles, i. 378.
Stripes, retained throughout groups of .birds, ii. 131 ; disappearance of, in adult mammals, ii. 303.
Strix flammea , ii. 105.
Structure, existence of unservice- able modifications of, i. 153.
Struggle for existence, in man, i* 180, 185.
Struthers, Dr., on the occurrence of the supra-condyloid foramen in the humerus of man, i. 28.
Sturnetta ludoviciam , pugnacity of the male, ii. 51.
Sturnus inilgaris, ii. 105.
Sub-species, i. 227.
Suffering, in strangers, indifference of savages to, i. 94.
Suicide, i. 172; formerly not re- garded as a crime, i. 94; rarely practised among the lowest savages,
i. 94.
Sutdas, stripes of young, ii. 184.
SUMATRA, compression of the nose by the Malays of, ii. 352.
Sumner, Archb., man alone capable of progressive improvement, i. 49.
Sun-birds, nidification of, ii. 169.
Superstitions, i. 182 ; prevalence of, i. 99.
Superstitious customs, i. 68.
Superciliary ridge in man, ii. 316, 318.
Supernumerary digits, more fre- quent in men than in women, l- 276; inheritance of, i. 285; early development of, i. 292.
Supra-condyloid foramen in the early progenitors of man, i. 206.
Suspicion, prevalence of, among am- mals, i. 39.
Sulivan, Sir B. J., on two stalli°DS attacking a third, ii. 241.
Swaljlow-tail Butterfly, i. 393.
Swallows deserting their young, l* 84, 90.
Swan, black, red beak of the, h* 227 ; black-necked, ii. 230; white, young of, ii, 211 ; wild, trachea o
the, ii. 59.
Swans, ii. 226, 230 ; young, ii. 208*
Swaysland, Mr., on" the arrival 01 migratory birds, i. 259.
Swinjioe, R., on the common rat hi Formosa and China, i. 50 ; on t ie sounds produced by the maleHoopo®*
ii. 62 ; on Dicrurm macrocc reus an the Spoonbill, ii. 179 ; on the youn& of Ardeola , ii. 190 ; on the habits 0 Turnix , ii. 202 ; on the habits ^ Bhynchdsa bcngalensis , ii. 203 ; 0
SYLVIA.
INDEX.
TENTHREDINIDiE. 467
Orioles breeding in immature plum- age, ii. 214, 215.
Sylvia atricapiUa , young of, ii. 219.
Sylvia cinerea , aerial love-dance of the male, ii. 68.
Sympathy, i. 168; among animals, i. 77 ; its supposed basis, i. 82.
Sympathies, gradual widening of, i.
100.
Syngnathous fishes, abdominal pouch in male, i. 210.
Sypheotides auritus , acuminated pri- maries of the male, ii. 64 ; ear-tufts of, ii. 73.
T.
Tabanid^e, habits of, i. 254.
Tadorna varieguta, sexes and young of, ii. 206.
Tadorna vulpanse.r , ii, 114,
Tahitians, i. 183 ; compression of the nose by the, ii. 352.
Tail, rudimentary, occurrence of, in man, i. 29 ; convoluted body in the extremity of the, i. 30 ; absence of, in man and the higher apes, i. 150, 194; variability of, in species of Macacus and in baboons, i. 150; presence of, in the early progenitors of man, i. 206 ; length of, in phea- sants, ii. 156, 164, 166; difference of length of the, in the two sexes of birds, ii. 164.
Tait, Lawson, on the effects of natu- ral selection on civilised nations, i. 168.
Tanager, scarlet, variation in the male, ii. 126.
Tanagra sestiva , ii. 180 ; age of ma- ture plumage in, ii. 213.
Tanagra rubra , ii. 126 ; young of, ii. 220.
Tanais , absence of mouth in the males of some species of, i. 255 ; relations of the sexes in, i. 315; dimorphic males of a species of, i. 328.
Tankerville, Earl, on the battles of wild bulls, ii. 240.
Tanysiptera , races of, determined from adult males, ii. 190.
Tanysiptera sylvia , long tail-feathers of, ii. 165.
Taphroderes distortus, enlarged left mandible of the male, i. 344.
Tapirs, longitudinal stripes of young, ii. 184, 303.
Tarsi, dilatation of front, in male beetles, i. 343.
Tarsius , i. 200.
Tasmania, half-castes killed by the natives of, i. 220.
Tattooing, i. 232 ; universality of, ii. 339.
Taste, in the Quadrumana, ii. 296.
Taylor, G. on Quiscalus major , i. 307.
Tea, fondness of monkeys for, i. 12.
Tear-sacks, of Ruminants, ii. 280.
Teebay, Mr., on changes of plumage in spangled Hamburgh fowls, i. 281.
Teeth, rudimentary incisor, in Rumi- nants, i. 17 ; posterior molar, in man, i. 25 ; wisdom, i. 26 ; diversity of, i. 108; canine, in the early pro- genitors of man, i. 206 ; canine, of male mammals, ii. 241 ; in man, reduced by correlation, ii. 325 ; staining of the, ii. 339 ; front, knocked out or filed by some sa- vages, ii. 340.
Tbgetmeieji, Mr., on the abundance of male pigeons, i. 306; on the wattles of game-cocks, ii. 98; on the courtship of fowls, ii. 117 ; on dyed pigeons, ii. 118.
Tembeta, ii. 341.
Temper, in dogs and horses, inherited, i. 40.
Tench, proportions of the sexes in the, i. 308, 309; brightness of male, during breeding season, ii. 13.
TenBBRIONIDJS, stridulation of, i. 379.
Tennent, Sir J. Em on the tusko of the Ceylon Elephant, ii. 248, 258 ; on the frequent absence of heard in the natives of Ceylon, ii. 321 ; on the Chinese opinion of the aspect of the Cingalese, ii. 345.
Tennyson, A., on the control of thought, i» 101.
Tenthredinio®, proportions of the sexes in, i. 314 ; fighting habits of male, i. 364 ; difference of the sexes in, i. 365.
2 h 2
468 TEPHRODORNIS.
INDEX.
TORTURES.
Tephrodomis , young of, ii. 190. Terai, i. 237.
Termites , habits of, i. 364.
Terns, white, ii. 228 ; and black, ii. 230.
Terns, seasonal change of plumage in, ii. 228.
Terror, common action of, upon the lower animals and man, i. 39. Testudo nigra , ii. 28.
Tetrao cupido , battles of, ii. 50 ; sexual difference in the vocal organs of, ii. 56.
Tetrao plutsianellus , dances of, ii. 68 ;
duration of dances of, ii. 100.
Tetrao scoticus , ii. 170, 185, 194. Tetrao tetrix , ii. 170, 185, 194; pug- nacity of the male, ii. 45.
Tetrao umhellus , pairing of, ii. 49; battles of, ii. 50 ; drumming of the male, ii. 61.
Tetrao urogalloidcs , dances of, ii. 100. Tetrao urogaltus , pugnacity of the male, ii. 45.
Tetrao urophasianus , inflation of the (esophagus in the male, ii. 57. Tlutmnobia, young of, ii. 190. Thaunnalea picta, display of plumage f by the male, ii. 89.
7 hecla , sexual differences of colouring in species of, i. 389.
Theda rubiy protective colouring of, i. 392.
Theridion, i. 337 ; stridulation of males of, i. 339.
Theridion lineaturn, variability of, i. 338,
Thomisus citrons , and T. floricolcns , difference of colour in the sexes of,
i. 337.
Thompson, J. H., on the battles of sperm-whales, ii. 240.
Thompson, W., on the colouring of the male char during the breeding sea- son, ii. 14; on the pugnacity of the males of Gallinula chloropus ,
ii. 41 ; on the finding of new mates by magpies, ii. 103 ; on the finding of new mates by Peregrine falcons, ii. 104.
Thorax, processes of, in male beetles, i. 370.
Tiiorell, T., on the proportion of the sexes in spiders, i. 315.
Thornback, difference in the teeth of the two sexes of the, ii. 6.
Thoughts, control of, i. 101.
Thrush, pairing with a blackbird, ii. 113; colours and nidification of the, ii. 170.
Thrushes, characters of young, ii.
| 185, 269.
Thug, his regrets, i. 94.
I TnuMM, absence of, in Ateles and Hy - hhates , i. 140.
Thury, M., on the numerical propor- tion of male and female births among the Jews, i. 301.
Thylacinus , possession of the marsu- pial sack by the male, i. 208.
! Tuysanura, i. 348.
I Tibia, dilated, of the male Crabro C)'i- brarius , i. 343.
Tibia and femur, proportions of, in the Aymara Indians, i. 119.
Tierra del Fuego, marriage-customs of, ii. 373.
Tiger, colours and markings of the, ii. 302.
Tigers, depopulation of districts by, in India, i. 134.
Tillus elongatus , difference of colour in the sexes of, i. 368.
Timidity, variability of, in the same species, i. 40.
Tineina, proportion of the sexes in,
i. 310.
Tipnla , pugnacity of male, i. 349.
Tits, sexual difference of colour in,
ii. 174.
Toads, ii. 25; male, treatment of ova by some, i. 210 ; male, ready to breed before the female, i. 260.
Toe, great, condition of, in the human
I embryo, i. 17.
| Tomtit, blue, sexual difference of co-
1 lour in the, ii. 174.
Tonga Islands, beardlessness of the natives of, ii. 322, 349.
Tooke, Horne, on language, i. 55.
Tools, tlint, i. 183 ; used by monkeys, i. 51 ; use of, i. 137.
Topknots in birds, ii. 74.
Tomicns villosus , proportion of the sexes in, i. 314.
Tortoise, voice of the male, ii. 331.
Tortures, submitted to by American savages, i. 95.
TOTANUS.
INDEX.
TURKEY.
469
Totanus , double moult in, ii. 81. Toucans, colours and unification of the, ii. 171 ; beaks and ceres of the, ii. 227.
Towns, residence in, a cause of dimi- nished stature, i. 115.
Toynbee, J., on the external shell of the ear in man, i. 21.
Trachea, convoluted and imbedded in the sternum, in some birds, ii. 59 ; structure of the, in Mhynchxa. ii. 203.
Trades, affecting the form of the skull, i. 147.
Tragelaphus , sexual differences of co- lour in, ii. 288.
Tragelaphus scriptus , dorsal crest of, ii. 282; markings of, ii. 299, 300. Tragopan, i. 270 ; swelling of the wattles of the male, during court- ship, ii. 72 ; display of plumage by the male, ii. 91 ; markings of the sexes of the, ii. 134.
Tragops dispur , sexual difference in the colour of, ii. 30.
Training, effect of, on the metal difference between the sexes of man, ii. 329.
Transfer of male characters to female birds, ii. 193.
Transmission, equal, of ornamental characters, to both sexes in mam- mals, ii. 297.
Traps, avoidance of, by animals, i. 49; use of, i. 137.
Treachery, to comrades, avoidance of, by savages, i. 88.
Tremex columbse , i. 365.
Tribes, extinct, i. 160; extinction of, i. 236.
Trichius , difference of colour in the sexes of a species of, i. 368.
Trimen, R., on the proportion of the sexes in South African butter- flies, i. 310; on the attraction of males by the female of Lasiocampa quercus , i. 312 ; on Pneumora, i. 358 ; on difference of colour in the sexes of beetles, i. 367 ; on moths ' brilliantly coloured beneath, i. 397 ; on mirnickry in butterflies, i. 412 ; on Gynanisa /sis, and on the ocellated spots of Lepidoptera, ii. 132 ; on Cytto Leda , ii. 133.
T ring a , sexes and young of, ii. 216. Tringa cornuta , ii. 82.
Triphxm , coloration of the species I of, i. 395.
Tristram, H. B., on unhealthy dis- tricts in North Africa, i. 244; on j the habits of the chaffinch in Palestine, i. 307 ; on the birds of the Sahara, ii. 172 ; on the animals inhabiting the Sahara, ii. 224. Triton enstatus , ii. 24.
Triton palmipes, ii. 24.
Triton punctatus, ii. 24, 25.
| Troglodytes vulgaris , ii. 198.
Trogons, colours and nidiiication of the, ii. 171, 173.
Tropic-birds, white only when ma- ture, ii, 228.
Tropics, freshwater fishes of the, ii. 17.
Trout, proportion of the sexes in, i.
308 ; male, pugnacity of the, ii. 3. Trox sabulosusj stridulation of, i. 380.
! Truth, not rare between members of the same tribe, i. 95 ; more highly appreciated by certain tribes, i 100. ’ Tui,rx)CH, Major, on the immunity of the negro from certain fevers, i.
Tumbler, almond, change of plumage in the, i. 294.
Turdus rnerula, ii. 170; young of, ii. 219.
Turdus migratorius , ii. 185.
Turdus musicus, ii. 170.
J urdus polyglottus , young of, ii. 21 9.
Turdus torquatus , ii. 170. j 1 urkey, swelling of the wattles of the male, ii. 72 ; variety of, with a top-knot, ii. 74 ; recognition of a dog by a, ii. 110; wild, pugnacity of young male, ii. 48 ; wild, notes of the, ii. 60 ; male, wild, accept- able to domesticated females, ii. 119; wild, first advances made by older females, ii. 121 ; wild, breast- tuft of bristles of the, ii. 179. Turkey-cock, scraping of the wings of, upon the ground, ii. 61 ; wild, display of plumage by, ii. 87 ; fighting habits of, ii. 98.
470
TURNER.
INDEX,
VERMIFORM.
Turner, Prof. W., on muscular fasci- culi in man referable to the panniculus carnosus, i. 19; on the occurrence of the supracondyloid foramen in the human humerus, i. 28 ; on muscles attached to the coccyx in man, i. 29 ; on the filum terminate in man, i. 30; on the variability of the muscles, i. 109 ; on abnornal conditions of the human uterus, i. 123; on the de- velopment of t he mammary glands, i. 209 ; on male fishes hatching ova in their mouths, i. 210.
Turnix, sexes of some species of, ii. 201, 207.
Turtle-dove, cooing of the, ii. 60.
Tuttle, H., on the number of species of man, i. 226.
Tylor, E. B., on emotional cries, gestures, &c., of man, i. 54-; on the origin of the belief in spiritual agencies, i. 66 ; on the primitive barbarism of civilised nations, i. 181 ; on the origin of counting, i. 181 ; on resemblances of the mental characters in different races of man, i. 232.
Type of structure, prevalence of, i.
211.
Typhceus, stridulating organs of, i. 378; stridulation of, i. 380.
Twtns, tendency to produce, here- ditary, i. 133.
Twite, proportion of the sexes in the, i. 307.
U.
Ugliness, said to consist in an approach to the lower animals, ii. 354.
Umbrella-bird, ii. 58, 59.
Umbrina , sounds produced by, ii. 23.
United States, rate of iucrease in, i. 131 ; influence of natural selection on the progress of, i. 179 ; change undergone by Europeans in the, i. 246.
Upupa epops , sounds produced by the male, ii. 62.
Uraniums, coloration of the, i. 396.
Uria troile , variety of, (= U lacry- mans ), ii. 127.
Urodela, ii. 24.
Urosticte Benjamin! , sexual differences in, ii. 151.
Use and disuse of parts, effects of, i. 116; influence of, on the races of man, i, 247.
Uterus, reversion in the, i. 123 ; more or less divided, in the human sub- ject, i. 123, 130 5 double, in the early progenitors of man, i. 206.
V.
Vaccination, influence of, i. 168.
Vancouver Island, Mr. Sproat on the savages of, i. 239 ; natives of, erad- ication of facial hair by the, ii-
348.
Vanellus cristatus , wing tubercles of the male, ii. 48,
Vanessas , i. 387 ; resemblance of lower surface of, to hark of trees, i- 392.
Variability, causes of, i. Ill; in man, analogous to that in the lower animals, i. 112; of the races of man, i. 225 ; greater in men than in women, i. 275; period of, rela- tion of the, to sexual selection, b 296 ; of birds, ii. 124; of secondary sexual characters in man, ii, 320.
Variation, correlated, i. 30; laws of, i. 113; in man, i. 185; analogous, i. 194; analogous, in plumage of birds, ii. 74.
Variations, spontaneous, i. 131.
Varieties, absence of, between two species, evidence of their distinct- ness, i. 215.
Variety, an object in nature, u* 230.
Variola, communicable between man and the lower animals, i. 11.
Vaur£al, i. 29.
VEDDAHS, monogamous habits of, ll* 363.
Veitch, Mr., on the aversion ot Japanese ladies to whiskers, 11#
349.
Vengeance, instinct of, i. 89. ^
Venus Erycina, priestesses of, ii- o0
Vermes, i. 327.
Vermiform appendage, i. 27.
VERREAUX.
INDEX.
WALLACE.
471
Verreaux, M., on the attraction of numerous males by the female of an Australian Bombyx , i. 312.
Vertebra, caudal, number of, in macaques and baboons, i. 150: of monkeys, partly imbedded in the body, i. 151.
Vertebral a, ii. 1 ; common origin of the, i. 203; most ancient pro- genitors of, i. 212; origin of the voice in air-breathing, ii. 331,
Vesicula prostatica, the homologue of the uterus, i. 31, 208.
Vibrissas, represented by long hairs in the eyebrows, i. 25,
Viduciy ii. 181.
Vidua axillaris , i. 269.
Villerme, M., on the influence of plenty upon stature, i. 115.
V inson, Aug., on the male of Epeirci nigra , i. 338.
Viper, difference of the sexes in the, ii. 29.
Virey, on the number of species of man, i. 226.
Virtues, originally social only, i. 93; gradual appreciation of, i. 165.
Viscera, variability of, in man, i. 109.
V iti Archipelago, population of the, i. 225.
Vlacovich, Prof., on the isckio-pubic muscle, i. 127.
Vocal music of birds, ii. 51.
Vocal organs of man, i. 58 ; of birds, i. 59 ; ii. 1G3 ; of frogs, ii. 28 ; of the Insessores, ii. 55 ; difference of, in the sexes of birds, ii. 56; pri- marily used in relation to the pro- pagation of the species, ii. 330.
Vogt, Carl, on the origin of species, i. 1 ; on the origin of man, i. 4 ; on the semilunar fold in man, i. 23; on the imitative faculties of micro- cephalous idiots, i. 57 ; on micro- cephalous idiots, i. 121; on skulls from Brazilian caves, i. 218; on the evolution of the races of man, i. 230; on the formation of the skull in women, ii. 317 ; on the Ainos and negroes, ii. 321 ; on the increased cranial difference of the sexes in man with race-develop- ment, ii. 329 ; on the obliquity of
the eye in the Chinese and Japanese, ii. 344.
Voice in mammals, ii. 274; in mon- keys and man, ii. 319; in man, ii. 330 ; origin of, in air-breathing vertebrates, ii. 331.
Von Baer, definition of advancement in the organic scale, i. 211.
Vulpian, Prof,, on the resemblance between the brains of nuin and of the higher apes, i. 11.
Vultures, selection of a mate by the female, ii. 116 ; colours of, ii. 229.
W.
Waders, young of, ii. 217.
Wagner, R., on the occurrence of the diastema iu a Kaflir skull, i. 126 ; on the bronchi of the black stork, ii. 60,
Wagtail, Ray’s, arrival of the male before the female, i. 260.
Wagtails, Indian, young of, ii. 190.
Waist, proportions of, in soldiers and sailors, i. 117.
Waitz, Prof., on the number of spe- cies of man, i. 226 ; on the colour of Australian infants, ii. 318 ♦ on the beard lessness of negroes ii. 321 ; on the fondness of mankind for ornaments, ii. 338 ; on the liability of negroes to tropical fevers after residence in a cold climate, i. 243 ; on negro ideas of female beauty, ii. 846 ; on Javanese and Cochin Chinese ideas of beauty, ii. 347.
W alckenaer and Gervais, on the Myriapoda, i, 340.
Waldeyer, M., on the hermaphro- ditism of the vertebrate embryo, i.
207.
Wales, North, numerical proportion of male and female births in, i. 301.
Walker, Alex., on the large size of the hands of labourers’ children, i. 117.
Walker, F., on sexual differences in the diptera, i. 348.
Wallace, Dr. A., on the prehensile
472
WALLACE.
INDEX.
WARBLER.
use of the tarsi in male moths, i. 256 ; on the rearing of the Ailan- thus silkmoth, i. 311 ; on breeding Lepidoptera, i. 311 ; proportion of sexes of Bombyx Cynthia, B. yama- vtai, and B. Pemyi, reared by, i. j 313 ; on the development of Bom - byx cynthia and B. yamamai, i. 346 ; on the pairing of Bombyx cynthia, i. 401 ; on the fertilisation of moths, i. 406.
Wallace, A. R.r on the origin of man, i. 4 ; on the power of imita- tion in man, i. 39 ; on the use of missiles by the orang, i. 52 ; on the varying appreciation of truth among different tribes, i. 100; on the limits of natural selection in man, i. 137, 158; on the occurrence of remorse among savages, i. 165 ; on the efiects of natural selection on civilized nations, i. 168 ; on the use of the convergence of the hair at the elbow in the orang, i. 193; on the contrast in the characters of the Malays and Papuans, i. 216 ; on the line of separation bet ween the i Papuans and Malays, i. 218 ; on the sexes of Ondthoptera Crcesus, i. 310 ; on protective resemblances, i. 322 ; on the relative sizes of the sexes of insects, i. 346 ; on Elaphomyia, i. 349 ; on the Birds of Paradise, i. 269 ; on the pugnacity of the males of Lcptorhyndms angustatus, i. 375 ; on sounds produced by Euchirus longimanus, i. 381 ; on the colours of Diadema , i. 388 ; on Eallima , i. 392 ; on the protective colouring of moths, i. 394 ; on bright colora- tion as protective in butterflies, i. 395 ; on variability in the Papi- lionid®, i. 402 ; on male and female butterflies inhabiting different sta- tions, i. 403 ; on the protective nature of the dull colouring of female butterflies, i. 403,405,414; on mimickry in butterflies, i. 412 ; on the mimickry of leaves by Phas- midse, i. 414 ; on the bright colours of caterpillars, i. 416 ; on brightly- coloured fishes frequenting reefs, ii.
17 ; on the coral snakes, ii. 31 ; on Paradisea apoda, ii. 74, 78 ; on
the display of plumage by male Birds of Paradise, ii. 88 ; on as- semblies of Birds of Paradise, ii. 101 ; on the instability of the ocel- lated spots in Ifipparchia Janira , ii. 132 ; on sexually limited in- heritance, ii. 155; on the sexual coloration of birds, ii. 166, 196, 197, 200, 206; on the relation between the colours and nidifica- tion of birds, ii. 166, 171 ; on the coloration of the Cotingid®, ii. 177; on the females .of Paradisea apoda and papuana, ii. 193; on the in- cubation of the cassowary, ii. 204; on protective coloration in birds, ii. 223; on the hair of the Papuans, ii. 340 ; on the Babirusa, ii. 264 ; on the markings of the tiger, ii. 302 ; on the beards of the Papuans, ii. 322 ; on the distribution of hair on the human body, ii. 375.
Walrus, development of the nicti- tating membrane in the, i. 23 ; tusks of the, ii 241, 248 ; use of the tusks by the, ii. 257.
Walsh, B. D., on the proportion of the sexes in Pupilio Turnus, i. 310; on the Cynipidas and Cecidomyidae, i. 314; on the jaws of Ammophila, i. 342; on Corydalis cornutus, i. 342; on the prehensile organs of male insects, i. 342 ; on the an- tennas of Penthe, i. 343; on the caudal appendages of dragon-flies, i. 344 ; on PUttyphyllum concavum, i. 356 ; on the sexes of the Epneme- rida?, i. 361 ; on the difference of colour in the sexes of Spectmm femo- ratum , i. 361 ; on sexes of dragon- flies, i. 301; on the difference of the sexes in the Ichneumonida?, i. 365 ; on the sexes of Orsodacna atra , i. 368 ; on the variation of the horns of the male Phanteus carni - fex, i. 370 ; on the coloration of the species of Anthocharis, i. 393.
Wapiti, battles of, ii. 240 ; traces of horns in the female, ii. 245 ; attack- ing a man, ii. 253 ; crest of the male, ii. 282 ; sexual difference in the colour of the, ii. 289.
Warbler, Hedge-, ii. 198 ; young of the, ii. 209.
WARBLERS.
INDEX.
WESTPHALIA.
473
Warblers, Superb, nidification of, ii. 169.
Wariness, acquired by animals, i. 50.
Warington, R., on the habits of the sticklebacks, ii. 2, 20 ; on the bril- liant colours of the male stickle- back during the breeding season, ii. 14.
Wart-iiog, tusks and pads of the, ii. 265.
Watchmakers, short-sighted, i. 118.
Wateriien, ii. 40.
Waterhouse, C. 0., on blind beetles,
i. 367 ; on difference of colour in the sexes of beetles, i. 367.
Waterhouse, G. Ii., on the voice of Hylobcttes agilis , ii. 332.
Water-ouzel, autumn song of the,
ii. 54.
Waterton, C.j on the pairing of a Canada goose with a Bernicle gan- der, ii. 114 ; on hares fighting, ii. 239 ; on the Bell-bird, ii. 79.
Wattles, disadvantageous to male birds in fighting, ii. 98.
Wealth, influence of, i. 169.
Weale, J. Mansel, on a South African caterpillar, i. 416.
Weapons, employed by monkeys, i. 51 ; use of, i. 137 ; offensive, of males, i. 257 ; of mammals, ii. 241 et seq.
Weaver-bird, ii. 54.
Weaver-birds, rattling of the wings of, ii. 62 ; assemblies of, ii. 101.
Webb, Dr., on the wisdom teeth, i. 25.
Wedgwood, Hcnsleigh, on the origin of language, i. 56.
Weevils, sexual difference in length of snout in some, i. 255.
Weir, Harrison, on the numerical proportion of the sexes in pigs and rabbits, i. 305; on the sexes of young pigeons, i. 306 ; on the songs of birds, ii. 52 ; on pigeons, ii. 109 ; on the dislike of blue pigeons to other coloured varieties, ii. 118; on the desertion of their mates by female pigeons, ii. 119.
Weir, J. Jenncr, on the nightingale and blackcap, i. 259; on the rela- tive sexual maturity of male birds, i. 261 ; on female pigeons deserting VOL. II.
a feeble mate, i. 262; on three starlings frequenting the same nest, i. 269; on the proportion of the sexes in Machetes pugnax and other birds, i. 306, 307 ; on the coloration of the Triph&mai, i. 395 ; on the rejection of certain cater- pillars by birds, i. 417 ; on sexual differences of the beak in the gold- finch, ii. 40 ; on a piping bullfinch, ii. 52 ; on the object of the night- ingale’s song, ii. 52 ; on song-birds, ii. 53; on the pugnacity of male fine-plumaged birds, ii. 93 ; on the courtship of birds, ii. 94 ; on the finding of new mates by Peregrine- falcons and Kestrels, ii. 104 ; on the bullfinch and starling, ii. 105 ; on the cause of birds remaiuing unpaired, ii. 107 ; on starlings aud parrots living in triplets, ii. 107 ; on re- cognition of colour by birds, ii. 110 ; on hybrid birds, ii. 113; on the selection of a greenfinch by a female canary, ii. 115 ; on a case of rivalry of fern, -ile bullfinches, ii. 121 ; on the maturity of the Golden-phea- sant, ii. 213.
Weisbach, Dr., measurement of men of different races, i. 216; on the greater variability of men than of women, i. 275; on the relative proportions of the body in the sexes of different races of man, ii. 320.
Wkloker, M., on Brachycephaly and Dolichocephaly, i, 148 ; on sexual differences in the skull in man, ii. 317.
Wells, Dr., on the immunity of coloured races from certain poisons, i. 243.
W estring, on the stridulation of Re~ duvius personatus , i. 350 ; on the Btridulating organs of the Coleo- ptera, i. 382 ; on sounds produced by Cychrus, i. 382 ; on the stridu- lation of males of Theridion , i. 339 ; on the stridulation of beetles, i. 379 ; on the stridulation of Omalo- ptia brunnea, i. 381.
Westphalia, greater proportion of female illegitimate children in, i. 301.
2 i
474
WESTROPP.
INDEX.
WOMEN.
Westropp, H. M., on the prevalence of certain forms of ornamentation, i. 233.
Westwood, J. 0., on the classification of the Hymenoptera, i. 188 ; on the Culicidos and Tabamdas, i. 254 ; on a Hymenopterous parasite with a sedentary male, i. 272 ; on the proportions of the sexes in Lucanus cerms and Siagamum, i. 313; on the absence of ocelli in female mu* tillidsc, i. 341 ; on the jaws of Atn- mophila , i. 342 ; on the copulation of insects of distinct species, i. 342 ; on the male of Gra))ro cribrarius , i. 343 ; on the pugnacity of male TipulfE i. 349 ; on the st rid illation of Pirates stridulus , i. 350; on the Cicadae, i. 351 ; on the stimulat- ing organs of the crickets, i. 354 ; on Pneumora , i. 357 ; on Ephippi- ger vitium, i. 355, 358; on the j pugnacity of the Mantides, i. 360 ; 1 on Platyblemnus , i. 361 ; on differ- ence in the sexes of the Agrionidre, i. 362 ; on the pugnacity of the males of a species of Tenthredinsc, i. 364 ; on the pugnacity of the male stag- ! beetle, i. 375; on Bledius iaurus \ and Smgonhtnij i. 375 ; on lamelli- i corn beetles, i. 378; on the colora- ' tion of Lithosia , i. 396.
Whale, Sperm- , battles of male, ii. 240.
WHALES, nakedness of, i. 148.
W iiATELY, Archb., language not pe- culiar to man, i. 53 ; on the primi- tive civilisation of man, i. 181.
Whewell, Prof., on maternal affec- tion, i. 40.
Whiskers, in monkeys, i. 192.
White, Gilbert, on the proportion of the sexes in the partridge, i. 306 ; | on the house-cricket, i. 352 ; on the object of the song of birds, ii. 52 ; j on the finding of new mates by I white owls, ii. 105; on spring j coveys of male partridges, ii. 107.
Whiteness, a sexnal ornament in ' some birds, ii. 232; of mammals inhabiting snowy countries, ii. 298.
W i Til’ e-throat, aerial love-dance of the male, ii. 68.
Widow-bird, polygamous, i. 269 ;
breeding plumage of the male, ii* 84, 97 ; female, rejecting the un- adorned male, ii. 120.
Widows and widowers, mortality of,
i. 176.
Wigkon, pairing with a pintail duck,
ii. 114.
WiLCKENS, Dr., on the modification of domestic animals in mountain- ous regions, i. 120 ; on a numerical relation between the hairs and ex- cretory pores in sheep, i. 248.
Wilder, Dr. Burt, on the greater frequency of supernumerary digits in men than in women, i. 276.
Williams, on the marriage-customs of the Fijians, ii. 374.
Wilson, Dr., on the conical heads of the natives of North-Western Ame- rica, ii. 351 ; on the Fijians, ii* 352; on the persistence of the fashion of compressing the skull, ii. 353.
Wing-spurs, ii. 162.
Wings, differences of, in the two sexes of butterflies and Hymeno- ptera, i. 345 ; play of, in the court- ship of birds, ii. 95.
Winter, change of colour of mam- mals in, ii. 298.
Witchcraft, i. 68.
Wives, traces of the forcible capture of, i. 182.
Wolf, winter change of the, ii* 298.
Wolff, on the variability of the vis- cera in man, i. 109.
Wollaston, T. V., on Eurygmthus , i. 344 ; on musical curculionidce, i* 378 ; on the stridulation ot'Acalles, i. 384.
Wolves learning to bark from dogs, i. 44; hunting in packs, i. 75.
Wolves, black, ii. 294.
Wombat, black varieties of the, ii* 294.
Women distinguished from men by male monkeys, i. 13 ; preponderance of, in numbers, i. 302; effects of selection of, in accordance with different standards of beauty, 11# 355 ; practice of capturing, ii* 360, 364 ; early betrothals and. slavery of, ii. 366 ; selection of, for beauty,
WONDER.
INDEX.
ZyG^ENIDjE.
475
ii. 372; freedom of selection by, in savage tribes, ii. 372.
Wonder, manifestations of, by ani- mals, i. 42.
Wonfor, Mr., on sexual peculiarities ! in the wings of butterflies, i. 345. j
Woolner, Mr., observations on the ear in man, i. 22.
Wood, J., on muscular variations in man, i. 109, 128, 129 ; on the i greater variability of the muscles in men than in women, i. 275.
Wood, T. W., on the colouring of the j orange-tip butterfly, i. 394; on the habits of the Satumiid®, i. 398 ; on the habits of Mennru Alberti, ii. 56; on Tetrao eupido, ii. 56 ; on the display of plumage bv male pheasants, ii. 89 ; on the ocellated spots of the Argus phea- sant, ii. 144 ; on the habits of the female Cassowary, ii. 204.
Woodcock, coloration of the, ii. 226.
Woodpecker, selection of a mate by the female, ii. 116.
Woodpeckers, ii. 56 ; tapping of, ii. 62 ; colours and nidification of the, ii. 171, 174, 223 ; characters of young, ii. 185, 199, 209.
Worm at. d, Mr., on the coloration of Hypopyra, i. 397.
Wounds, healing of, i. 13.
Wren, ii. 198; young of the, ii. 209.
Wright, C. A., on the young of Orocetes and Petrocincla, ii. 220.
Wright, Chauncey, on correlative j acquisition, ii. 335 ; on the enlarge- j ment of the brain in man, ii. 391.
Wright, Mr., on the Scotch deer- hound, ii. 261 ; on sexual preference in dogs, ii. 271 ; on the rejection of a horse by a mare, ii. 272.
Wright, W. von, on the protective plumage of the Ptarmigan, ii. 81.
Writing, i. 182.
Wyman, Prof., on the prolongation of the coccyx in the human embryo, i. 16 ; on the condition of the great toe in the human embryo, i. 17 ; on
variation in the skulls of the natives of the Sandwich Islands, i. 108 ; on the hatching of the eggs in the mouths and branchial cavities of male fishes, i. 210, ii. 20.
X.
Xenarciiub, on the Oicadse, i. 350.
Xeiwrhynchus, sexual difference in the colour of the eyes in, ii. 129.
Xip/wpJwrus Hellerii, peculiar anal fin of the male, ii. 9, 10.
Xylocopa, difference of the sexes in, i. 366.
Y.
Yarrell, W., on the habits of the Cyprinidie, i. 309 ; on Baia clavata, ii. 2; on the characters of the male salmon during the breeding season, ii. 4, 14; on the characters of the rays, ii. 6; on the gemmeous drago- nct, ii. 8 ; on the spawning of the salmon, ii. 19 ; on the incubation of the Lophobranehii, ii. 21 ; on rivalry in song-birds, ii. 53 ; on the trachea of the swan, ii. 60 ; on the moulting of the anatida, ii. 85 ; on an in- stance of reasoning in a gull, ii. 108; on the young of the waders, ii. 217.
Yellow fever, immunity of negroes and mulattoes from, i. 243,
Youatt, Mr., on the development of the horns in cattle, i. 284.
Yura-CAUAS, their notions of beauty, ii. 347.
Z.
Zebra, rejection of an ass by a female, ii. 295 ; stripes of the, ii. 302.
Zebus, humps of, i. 284.
Zigzags, prevalence of, as ornaments, i. 233.
Zincke, Mr., on European emigration to America, i. 179.
Zootoai viviparu, sexual difference in the colour of, ii. 36.
Zygainid^, coloratiou of the, i. 396.
THE END.
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