66 colour, odour, or voice, which such males, general rule, are thus coloured, the males may possess. It is this second kind of being rusty-red" (vol. i. p. 283). Now, "sexual selection" (and which alone de- if these cats were only known in a wild serves the name) that is important for state, Mr. Darwin would certainly bring the establishment of Mr. Darwin's views, them forward amongst his other instances but its valid action has to be proved. of alleged sexual selection, though we Now, to prove the existence of such a now know the phenomenon is not due to power of choice Mr. Darwin brings forward any such cause. A more striking instance, a multitude of details respecting the sexu- however, is the following: With the al phenomena of animals of various classes; pigeon, the sexes of the parent species do but it is the class of birds which is mainly not differ in any external character; relied on to afford evidence in support of nevertheless, in certain domesticated the exercise of this power of choice by fe- breeds the male is differently coloured male animals. We contend, however, that from the female. The wattle in the Engnot only is the evidence defective even lish carrier-pigeon and the crop in the here, but that much of his own evidence is pouter are more highly developed in the in direct opposition to his views. While male than in the female; " and " this has the unquestionable fact, that male sexual arisen, not from, but rather in opposition to, characters (horns, mane, wattles, &c., &c.) the wishes of the breeder;" which have been developed in many cases where amounts to a positive demonstration that sexual selection has certainly not acted, sexual characters may arise spontaneousrenders it probable, à priori, that the un- ly, and, be it noted, in the class of birds. known cause which has operated in these The uncertainty which besets these numerous cases has operated in those in- speculations of Mr. Darwin is evident at stances also which seem to favour the hy-every turn. What at first could be pothesis supported by Mr. Darwin. Still thought a better instance of sexual seleche contends that the greater part of the tion than the light of the glowworm, exbeauty and melody of the organic world is hibited to attract her mate? Yet the disdue exclusively to this selective process, covery of luminous larvæ, which of course by which, through countless generations, have no sexual action, leads Mr. Darwin to the tail of the peacock, the throat of the observe: "It is very doubtful whether humming-bird, the song of the nightin- the primary use of the light is to guide gale, and the chirp of the grasshopper the male to the female" (vol. i. p. 345). have been developed by females, age after Again, as to certain British field-bugs, he age, selecting for their mates males pos- says: "If in any species the males had sessing in a more and more perfect de- differed from the females in an analogous gree characters which must thus have been manner, we might have been justified in atcontinually and constantly preferred. tributing such conspicuous colours to sexual selection with transference to both sexes" (vol. i. p. 350). As to the stridulating noises of insects (which is assumed to be the result of sexual selection), Mr. Darwin remarks of certain Neuroptera: "It is rather surprising that both sexes should have the power of stridulating, as the male is winged and the female wingless" (vol. i. p. 366); and he is again surprised to find that this power is not a sexual character in many Coleoptera (vol. i. Yet, after all, Mr. Darwin concedes in principle the very point in dispute, and yields all for which his opponents need argue, when he allows that beautiful and harmonious variations may occur spontaneously and at once, as in the dark or spangled bars on the feathers of Hamburgh fowls (" Descent of Man," vol. i. p. 281). For what difference is there, other than mere difference of degree, between the spontaneous appearance of a few beautiful new feathers with harmoni- p. 382). ous markings and the spontaneous appearance of a whole beautiful clothing like that of the Tragopans? Again, on Mr. Darwin's own showing, it is manifest that male sexual characters, such as he would fain attribute to sexual selection, may arise without any such action whatever. Thus he tells us, "There are breeds of the sheep and goat, in which the horns of the male differ greatly in shape from those of the female;' and " with tortoise-shell cats, the females alone, as a Moths and butterflies, however, are the insects which Mr. Darwin treats of at the greatest length in support of sexual selection. Yet even here he supplies us with positive evidence that in certain cases beauty does not charm the female. He tells us : "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 dingy to this, however, we may well hesitate, males."- - vol. i. p. 400. when Mr. Darwin tells us, as he does, that seeing the habitual contests of the males, As to the Bombycidæ he adds: "it is surprising that they have not gener"The females lie in an almost torpid state, ally become, through the effects of sexual and appear not to evince the least choice in re-selection, larger and stronger than the fegard to their partners. This is the case with males;" and this the more as "the males the common silk-moth (B. mori). Dr. Wallace, suffer from their small size," being "liable who has had such immense experience in breed- to be devoured by the females of their own ing Bombyx cynthia, is convinced that the fe- species" (vol. ii. p. 7). The cases cited males evince no choice or preference. He has by our Author with regard to fishes, do kept above 300 of these moths living together, not even tend to prove the existence of and has often found the most vigorous females sexual selection, and the same may be said mated with stunted males." as to the numerous details given by him Nay, about Reptiles and Amphibians. rather the facts are hostile to his views. Thus, he says himself, "It is surprising that frogs and toads should not have aequired more strongly-marked sexual differences; for though cold-blooded, their pas sions are strong" (vol. ii. p. 26). But he cites a fact, than which it would be diffi cult to find one less favourable to his cause. Nevertheless, we do not find, for all this, any defect of colour or markings, for, as Mr. Alfred Wallace observes (Nature, March 15th, 1871, p. 182), " the Bombyces are amongst the most elegantly coloured of all moths." Mr. Darwin gives a number of instances of sexual characters, such as horns, spines, &c., in beetles and other insects; but there is no fragment of evidence that such structures are in any way due to feminine caprice. Other structures are described and figured, which doubtless do aid the sexual act, as the claws of certain Crustacea; but these are often of such size and strength (e.g. in Callianassa and Orchestia) as to render any power of choice on the part of the female in the highest degree incredible. He adds:" Dr. Günther informs me that he has several times found an unfortunate female toad dead and smothered from having been so closely embraced by If female selecthree or four males." tion was difficult in the case of the female salmon, it must be admitted to have been singularly infelicitous to the female toad. We will now notice some facts brought Similarly with the higher classes, i. e. forward by Mr. Darwin with regard to Fishes, Reptiles, and Beasts, we have de-beasts. And first, as to the existence of scriptions and representations of a numchoice on the part of the females, it may ber of sexual peculiarities, but no evidence be noted that "Mr. Blenkiron, the greatest whatever that such characters are due to breeder of race-horses in the world says female selection. Often we have statethat stallions are so frequently capricious ments which conflict strongly with a be- in their choice, rejecting one mare and lief in any such action. Thus, e.g., Mr. without any apparent cause taking to anDarwin quotes Mr. R. Buist, Superintend- other, that various artifices have to be ent of Fisheries, as saying that male habitually used." salmon "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."... "The keeper of Stormontfield found in the northern Tyne about 300 dead salmon all of which with one exception were males; and he was convinced that they had lost their lives by fighting.". vol. ii. p. 3. The female's choice must here be much limited, and the only kind of sexual selection which can operate is that first kind, determined by combat, which, we before observed, must rather be ranked as a kind of "natural selection." Even with regard "He has never known a mare to reject a horse;" though this has occurred in Mr. Wright's stable. Some of the most marked sexual characters found amongst mammals, are those which exist in apes. These are abundantly noticed by Mr. Darwin, but his treatment of them seems to show his inability to bring them within the scope of his theory. It is well known that certain apes are distinguished by the lively colours or peculiarities as to hair possessed by the males, while it is also notorious that their vastly superior strength of body and length of fang, would render resistance on the part of the female difficult and perilous, even were we to adopt the utterly gratuitous supposition, that at seasons of sexual excitement the female shows any disposition to coyness. Mr. Darwin has no facts to bring forward to prove the exercise of any choice on the part of female apes, but gives in support of his views the following remarkable passage: : "Must we attribute to mere purposeless variability in the male all these appendages of hair and skin? It cannot be denied that this is possible; for, with many domesticated quadrupeds, certain characters, apparently not derived through reversion from any wild parent-form, have appeared in, and are confined to the males, or are more largely developed in them than in the females, for instance, the hump in the male zebu-cattle of India, the tail in fat-tailed rams, the arched outline of the forehead in the males of several breeds of sheep, the mane in the ram of an African breed, and, lastly, the in mane, long hair on the hinder legs, and the dewlap in the male alone of the Berbura - vol. ii. p. 284. goat. If these are due, as is probable, to simple variability, then, he adds, "It would appear reasonable to extend the same view to the many analogous characters occurring in animals under a state of nature. Nevertheless I cannot persuade myself that this view is applicable in many cases, as in that of the extraordinary development of hair on the throat and fore-legs of the male Ammotragus, or of the immense beard of the Pithecia (monkey)."— vol. ii. p. 285. But one naturally asks, Why not? Mr. Darwin gives no reason (if such it may be called) beyond that implied in the gratuitous use of the epithet "purposeless" in the passage cited, and to which we shall return. In the Rhesus monkey the female appears to be more vividly coloured than the male; therefore Mr. Darwin infers (grounding his inference on alleged phenomena in birds) the sexual selection is reversed, and that in this case the male selects. This hypothetical reversion of a hypothetical process to meet an exceptional case will appear to many rash indeed, when they reflect that as to teeth, whiskers, general size, and superciliary ridges this monkey "follows the common rule of the male excelling the female" (vol. ii. p. 294). To turn now to the class on which Mr. Darwin especially relies, we shall find that even Birds supply us with numerous instances which conflict with his hypothesis. Thus, speaking of the battling of male waders, our author tells us : -"Two were seen to be thus engaged for half an hour, until one got hold of the head of the other, which would have been killed had not the observer interfered; the female all the time looking on as a quiet spectator" (vol. ii. p. 41). As these battles must take place generally in the absence of spectators, their doubtless frequently fatal termination must limit greatly the power of selection Mr. Darwin attributes to the females. The same limit is certainly imposed in the majority of Gallinaceous birds, the cocks of which fight violently; and there can be little doubt but that, as an almost invariable rule, the victorious birds mate with the comparatively passive hens. Again, how can we explain, on Mr. Darwin's hypothesis, the existence of distinguishing male sexual marks, where it is selects? Yet the wild turkey-cock, a disthe male and not the female bird which tinguished bird enough, is said by Mr. Darwin (vol. ii. p. 207) to be courted by the females; and he quotes (vol. ii. p. 120) Sir R. Heron as saying, "that with peafowl, the first advances are always made by the female." And of the capercailzie. he says, "the females flit round the male while he is parading, and solicit his attention." But though, of course, the sexual instinct always seeks its gratification, does the female ever select a particular plumage? The strongest instance given by Mr. Darwin is as follows: "Sir R. Heron during many years kept an account of the habits of the peafowl, which he bred in large numbers. He states that the hens have frequently great preference for a particular peacock. They were all so fond of an old pied cock, that one year, when he was confined though still in view, they were constantly assembled close to the trellice-walls of his prison, and would not suffer a japanned peacock to touch them. On his being let out in the autumn, the oldest of the hens instantly courted him, and was successful in her courtship. The the hens all courted his rival. This rival was a next year he was shut up in a stable, and then japanned or black-winged peacock, which to our eyes is a more beautiful bird than the com mon kind." — vol. ii. p. 119. Now no one disputes as to birds showing preferences one for another, but it is quite a gratuitous suggestion that the pied plumage of the venerable paterfamilias was the charm which attracted the opposite sex; and even if such were the case, it would seem (from Mr. Darwin's concluding remark) to prove either that the peahen's taste is so different from ours, that the peacock's plumage could never have been developed by it, or (if the taste of these peahens were different from that of most peahens) that such is the insta bility of a vicious feminine caprice, that no ward sign indicated to their would-be constancy of coloration could be produced destroyer that its prey was a disgusting by its selective action. morsel." As to birds, he believes that brilliance of plumage is developed where not hurtful, and that the generally more sober plumage of the hens has been produced by natural selection, killing off the more brilliant ones exposed during incu bation to trying conditions. Mr. Darwin bases his theory of sexual selection greatly on the fact that the male birds display the beauty of their plumage with elaborate parade and many curious and uncouth gestures. But this display is not exclusively used in attracting and stimulating the hens. Thus he admits that "the males will sometimes display their ornaments when not in the presence of the females, as occasionally occurs with the grouse at their balz-places, and as may be noticed with the peacock; this latter bird, however, evidently wishes for a spectator of some kind, and will show off his finery, as I have often seen, before poultry or even pigs" (vol. ii. p. 86). Again, as to the brilliant Rupicola crocea, Sir R. Schomburgk says: "A male was capering to the apparent delight of several others" (vol ii. p. 87). From the fact of "display" Mr. Darwin concludes that "it is obviously probable that the females appreciate the beauty of their suitors" (vol. ii. p. 111). Our Author, however, only ventures to call it "probable," and he significantly adds: "It is, however, difficult to obtain direct evidence of their capacity to appreciate beauty." And again he says of the hen bird: "It is not probable that she consciously deliberates; but she is most excited or attracted by the most beautiful, or melodious, or gallant males" (vol. ii. p. 123). No doubt the plumage, song, &c., all play their parts in aiding the various processes of life; but to stimulate the sexual instinct, even supposing this to be the object, is one thing-to supply the occasion for the exercise of a power of choice is quite another. Certainly we cannot admit what Mr. Darwin affirms (vol. ii. p. 124), that an "even occasional preference by the female of the more attractive males would almost certainly lead to their modification." A singular instance is given by Mr. Darwin (vol. ii. p. 111) in support of his view, on the authority of Mr. J. Weir. It is that of a bullfinch which constantly attacked a reed-bunting, newly put into the aviary; and this attack is attributed to a sort of jealousy on the part of the blackheaded bullfinch of the black head of the bunting. But the bullfinch could hardly be aware of the colour of the top of its own head! Mr. Wallace accounts for the brilliant colours of caterpillars and many birds in another way. The caterpillars which are distasteful must have gained if "some out Now as Mr. Wallace disposes of Mr. Darwin's views by his objections, so Mr. Darwin's remarks tend to refute Mr. Wallace's positions, and the result seems to point to the existence of some unknown innate and internal law which determines at the same time both coloration and its transmission to either or to both sexes. At the same time these authors, indeed, show the harmony of natural laws and processes one with another, and their mutual interaction and aid. It cannot be pretended that there is any evidence for sexual selection except in the class of Birds. Certain of the phe nomena which Mr. Darwin generally attributes to such selection must be due, in some other classes, to other causes, and there is no proof that sexual selection acts, even amongst birds. But in other classes, as we have seen, sexual characters are as marked as they are in the feathered group. Mr. Darwin, indeed, argues that birds select, and assumes that their sexual characters have been produced by such sexual selection, and that, therefore, the sexual characters of beasts have been similarly evolved. But we may turn the argument round and say that sexual characters not less strongly marked exist in many beasts, reptiles, and insects, which characters cannot be due to sexual selection; that it is, therefo: e, probable the sexual characters of birds are not due to sexual selection either, but that some unknown internal cause has equally operated in each case. The matter, indeed, stands thus: Of animals possessing sexual characters there are some in which sexual selection cannot have acted; others in which it may possibly have acted; others again in which, according to Mr. Darwin, it has certainly acted. It is a somewhat singular conclusion to deduce from this that sexual selection is the one universal cause of sexual charaeters, when similar effects to those which it is supposed to cause take place in its ab mentation of these," and the "occasional | female Argus pheasant can appreciate the preference" by females in confinement for refined beauty of the plumage of her mate, particular males. Is there here any suffi-"will be compelled to admit that the excient foundation for such a superstructure? traordinary attitudes assumed by the In the first place, in insects, e.g. butterflies, male during the act of courtship, by which we have often many brilliant males crowd- the wonderful beauty of his plumage is ing in pursuit of a single female. Yet, as fully displayed, are purposeless; and this Mr. Wallace justly observes, "Surely the is a conclusion which I for one will never male who finally obtains the female will admit." It seems then that it is this imbe either the most vigorous, or the strong- aginary necessity of attributing purposeest-winged, or the most patient - the one lessness to acts, which determines Mr. who tires out or beats off the rest." Sim- Darwin to attribute that peculiar and speilarly in birds strength and perseverance cial purpose to birds' actions which he will, no doubt, generally reward the suitor does attribute to them. But surely this possessing those qualities. Doubtless, difficulty is a mere chimæra. Let it be also, this will generally be the most beau- granted that the female does not select; tiful or most melodious; but this will sim- yet the display of the male may be useful ply be because extra beauty of plumage, in supplying the necessary degree of or of song, will accompany supereminent stimulation to her nervous system, and to vigour of constitution and fulness of vitality. What has been before said as to the fierce combats of cock-birds must be borne in mind. that of the male. Pleasurable sensation, perhaps very keen in intensity, may thence result to both. There would be no difficulty in suggesting yet other purposes if we were to ascend into higher speculative regions. Mr. Darwin has given us in one place a very remarkable passage; he says:— had the power of choice only by observing the eagerness of the wooers to please her, and to display their finery.” — vol. ii. p. 122. But that internal spontaneous powers are sufficient to produce all the most varied or bizarre sexual characters which any birds exhibit, is actually demonstrated by the class of insects, especially cat"With respect to female birds feeling a preerpillars which from their sexless unde- ference for particular males, we must bear in veloped state can have nothing to do with mind that we can judge of choice being exerted, the kind of selection Mr Darwin advocates. only by placing ourselves in imagination in the Yet amongst caterpillars we not only find same position. If an inhabitant of another some ornamented with spots, bands, planet were to behold a number of young russtripes, and curious patterns, "perfectly tics at a fair, courting and quarrelling over a definite in character and of the most pretty girl, like birds at one of their places of brilliantly contrasted hues. We have assemblage, he would be able to infer that she also many ornamental appendages; beautiful fleshy tubercles or tentacles, hard spines, beautifully coloured hairs arranged in tufts, brushes, starry clusters, or long pencils, and horns on the head and tail, either single or double, pointed or clubbed." Mr. Wallace adds, Now if all these beautiful and varied ornaments can be produced and rendered constant in each species by some unknown cause quite independent of sexual selection, why cannot the same cause produce the colours and many of the ornaments of perfect insects; we may also add, the colours and ornaments of all other animals, including birds? There is, however, another reason which induces Mr. Darwin to accept sexual selection; and it is probably this which, in his mind, mainly gives importance to the facts mentioned as to the plumage and motions of birds. He says of "display," "It is incredible that all this display should be purposeless" (vol. ii. p. 399); and again (vol. ii. p. 93), he declares that any one who denies that the Now here it must be observed that, as is often the case, Mr. Darwin assumes the very point in dispute, unless he means by "power of choice' mere freedom of physical power. If he means an internal, mental faculty of choice, then the observer could attribute such power to the girl only if he had reason to attribute to the rustics an intellectual and moral nature similar in kind to that which he possessed himself. Such a similarity of nature Mr. Darwin, of course, does attribute to rational beings and to brutes; but those who do not agree with him in this would require other tests than the presence of ornaments, and the performance of antics and gestures unaccompanied by any evidence of the faculty of articulate speech. Such, then, is the nature of the evidence on which sexual selection is supposed to rest. To us the action of sexual selection scarely seems more than a possibility, the |