The Play of Animals
Chapter 4: The Play of Animals (continued)
THE treatment of this class of plays .in a separate chapter is justified not only on the ground of its importance to animal psychology, but also for two reasons inherent in its nature. The first of these reasons is that it embraces the vexed question of sexual selection, and the second reason is that this kind of play differs from all that we have previously considered in being, strictly speaking, not mere practice preparatory to the exercise of an instinct, but rather its actual working. Yet it is universally spoken of as play, and consequently our first question is, How far is this designation correct?
In considering it we are at once brought face to face with the problem of sexual selection, for Darwin regards all phenomena connected with love play as the direct result of the operations of this, his second great principle of evolution. Sexual selection, then, involves two distinct phenomena: on the one hand the conflict between males for the possession of a female; and on the other hand the preference of the latter for certain qualities or capacities in the former. Each of these phenomena is supposed to produce its own effect in the modification of characters. The first, being only a
(230) special case of natural selection, is challenged by no one. The selective principle involved in the second is not the mechanical law of survival of the fittest, but rather the will of a living, feeling being capable of making a choice, and is much like that employed in artificial breeding. Spencer has spoken of natural selection as a "survival of the fittest," and a fitting designation of this theory of sexual selection would be "a multiplication of the most pleasing."
Let us take an example. The male cicada has on one wing a vein set with fine teeth, on which he fiddles with the other wing. Only males can produce this music. " The ancient Greeks knew this, for Anacreon congratulated the cicadas, in a poem that has come down to us, because they had dumb wives." " Here is the key to the riddle. The origin of the musical apparatus is easily explained by means of the male's rivalry. If we assume that the females enjoy the music—and it has been proved that they do—then we see why and how a singing instrument was gradually developed from the male's wings and has been improved to its present perfection, for the female would always prefer the male that sang best. Thus the superior musical apparatus of the father would be inherited by his sons, and so on. In this way there must necessarily be much progress in the development of this function in the course of several generations, the preference of better singers constantly tending to improve the singing apparatus until it can be improved no further."  In the same way the musical performance of birds, the arts of flying and dancing, the strange and beautiful colours
(231) and forms, are all to be considered as "wedding garments," so to speak.
But many voices worthy of attention have been raised against this theory of a choice of the most pleasing by the female. Wallace takes the lead in this opposition, and many scientists agree with him either wholly or in part. I may mention Tylor, Spencer, Wallaschek, Hudson, Lloyd Morgan. 
Wallace has expressed his view in various of his works, the most important being the Natural Selection and the Darwinism, that Darwin's assumption of a kind of aesthetic taste in the female governing her choice is as far from the truth as is the assumption that the bee is a good mathematician. But more than that, he maintains that it is by no means certain that the female makes any choice at all. "Any one who reads these most interesting chapters (in Darwin's Descent of Man) will admit that the fact of the display is demonstrated, and it may also be admitted as highly probable that the female is pleased or excited by the display. But it by no means follows that slight differences in the shape, pattern, or colours of the ornamental plumes are what lead a female to give the preference to one male over another; still less that all the females of a species, or the great majority of them, over a wide area of country and for many successive generations, prefer exactly the same modifications of colour or ornament." 
But we ask, What then is the cause of these phenomena, if there is no choice by the female? How do the beautiful colours and characteristic forms of male birds arise? Wallace answers these questions as follows: In the first place, it is not at all strange that animals should have colour. In all Nature colour is the rule, black and white are exceptions. " The presence of some colour, or even of many brilliant colours, in animals and plants would require no other explanation than does that of the sky or the ocean, of the ruby or the emerald—that is, it would require a purely physical explanation only." The kind of colours, however, is principally determined by natural selection. Colouring for offence and defence is very important in the animal world, a principle which was clearly recognised before the time of this misleading idea of sexual selection. Other peculiarities, such as broad white bands and white or coloured spots,  serve as distinguishing marks to those that live in companies.
These marks are important not only in times of danger, when they make it easier for the young to follow the old ones, but they also form a kind of bond for the social life, and in addition to that probably serve a, useful purpose in hindering the cross-breeding of closely related species. The symmetrical marking which renders the individual recognisable from either side seems to be for this purpose, as we conclude from the facility with which it is lost in domestication. To the same origin may be attributed the characteristic call
(233) of the male and the female's answering cry. " These are evidently a valuable addition to the means of recognition of the two sexes, and are a further indication that the pairing season has arrived; and the production, intensification, and differentiation of these sounds and odours are clearly within the power of natural selection. The same remark will apply to the peculiar calls of birds, and even to the singing of the males. These may well have originated merely as a means of recognition between the two sexes of a species and as an invitation from the male to the female bird. When the individuals of a species are widely scattered, such a call must be of great importance in enabling pairing to take place as early as possible, and thus the clearness, loudness, and individuality of the song becomes a useful character, and therefore the subject of natural selection." Thus sexual selection would be absorbed in natural selection, and Wallace advances two principles to assist in the absorption. Many characteristic markings and decorative colourings are, according to A. Tylor, closely connected with anatomical structure. Since the clearest colours show where the most important nerves run, their intersections form all sorts of figures. And " as the nerves everywhere follow the muscles, and these are attached to the various bones, we see how it happens that the tracts in which distinct developments of colour appear should so often be marked out by the chief divisions of the bony structure in vertebrates, and by the segments in the annulosa." 
If, then, colouring is connected with nerve distribution it must be largely dependent on good health, and brilliant colour becomes an indication of robust health. This is true also of other kinds of external ornamentation, especially of the size of the tail. The perfect adaptation of animals to their environment produces in them a superabundance of vigour which contributes to the size and brilliance of plumage that we admire in such birds as the pheasant, parrot, humming bird, etc. To the question why this is the case with males alone it may be answered that the female has the greater need of protection. This view is supported by the fact that in general, female birds of those species that have well-protected nests are as brightly coloured as the males.
Wallace applies this principle to skill in flight and dancing as well as to ornamentation, the same principle of superabundant energy which we found in the Schiller-Spencer theory of play. " The display of these plumes will result from the same causes which led to their production. Just in proportion as the feathers themselves increased in length and abundance, the skin muscles which serve to elevate them would increase also; and the nervous development, as well as the supply of blood to these being at a maximum, the erection of the plumes would become a habit at all periods of nervous or sexual excitement." . . . " During excitement and when the organism develops superabundant energy, many animals find it pleasurable to exercise their various muscles, often in fantastic ways, as seen in the gambols of kittens, lambs, and other young animals. But at the time of pairing male birds are in a state of the most perfect development, and possess an enormous store of vitality; and under the excitement of the sexual
(235) passion they perform strange antics or rapid flights, as much probably from the internal impulse to motion and exertion as with any desire to please their mates." 
The act of singing, too, which was originally a means of recognition, " is evidently a pleasurable one, and it probably serves as an outlet for superabundant nervous energy and excitement, just as dancing, singing, and field sports do with us.".
These are the essentials of Wallace's theory. Selection through the female is excluded; at the most he thinks we may say that she prefers the " most vigourous, defiant, and mettlesome male," and so indirectly favours the ornamentation which results from abundant energy.
In this presentation of Wallace's theory I have maintained a careful distinction which is not made clear in his own works, but without which it is difficult, in my opinion, to understand thoroughly the meaning of his ideas. I mean the distinction between the biological principles that would refer our problem to the familiar operations of natural selection, and such physiological theories as those of Tylor and Spencer. The former are of the greatest value, and will lead, I believe, to important modifications of the Darwinian system, while in the latter there is no inherent vitality, though Wallace seems to lay great stress on them.
Turning now to the secondary aspect of this theory, we set out from the fact that the characteristic marks and appendages of animals are closely connected with their anatomical structure, just as, in a common disease, an eruption occurs on the forehead which corresponds exactly to the distribution of the ophthalmic division of
(236) the fifth cranial nerve. Supposing this to be a fact, still nothing has been said that is prejudicial to the theory of sexual selection—it must necessarily have some sort of physiological basis. However, I for one can not quite conceive how such developments as, for instance, a peacock's tail, can be derived from beginnings so insignificant, simply by a superabundance of energy. This is very delicate ground, for the hypothesis of surplus energy continuing through thousands of generations seems to me to accord little with the laws of natural selection, which are like the old laws of reward: they give with niggardly hand what is essential for the preservation of the species and no more.
However, Wallace thinks that such extraordinary developments occur only when the species has acquired an assured position in life—in fact, " perfect success in the struggle for existence . . . . The enormously lengthened plumes of the bird of paradise and of the peacock are rather injurious than beneficial in the bird's ordinary life. The fact that they have been developed to so great an extent in a few species is an indication of such perfect adaptation to the conditions of existence, that there is in the adult male at all events a surplus of strength, vitality, and growth power, which is able to expend itself in this way without injury." 
But it is a well-known fact and a legitimate deduction from the principle of selection that such perfect adaptation to surrounding conditions produces a fixed type and precludes further development, just in proportion to its perfection. Thus., even if we suppose that
(237) the ancestors of the peacocks, from the time when they attained a certain assurance of existence, were constantly in possession of surplus energy that favoured the production of strong (and useless) feathers, it is yet inexplicable how a still further development was attained, such as Wallace indicates. That such hindrances should arise before adaptation is out of the question, and it seems hardly possible after it, without the aid of sexual selection, for we see that success attained in the struggle for life prevents Nature from further directing the growing energies. The contest of males in which the strongest have the advantage would then come prominent forward as the only possible explanation. Wallace, however, has but cursorily referred to this principle and rightly, as I believe, for it is difficult to see how selection acting through the contests of courtship could directly favor the development of such peculiarities, since we can hardly suppose that surplus energy would find its only expression in them.
Perhaps Wallace recognised this difficulty when he wrote, " As all the evidence goes to show that, so far as female birds exercise any choice, it is of the `most vigorous, defiant, and mettlesome' males, this form of sexual selection will act in the same direction (as natural selection), and help to carry on the process of plume development to its culmination." 
With these words, however hypothetical their form, Wallace overturns his whole argument, for if it is once admitted that the female chooses the strongest male, the chief point of the Darwinian theory is conceded. Whether her preference is for strength and courage
(238) or for beauty is of little consequence; the important thing is that a choice is made. \
Wallace's further deductions from the arts of dancing, flying, and singing will not detain us long. It is pretty well established that bird songs are inherited, generally speaking, and it seems quite as certain, if not more so, that characteristic dances and skill in flight have the same origin. Hudson says: " But every species or group of species has its own inherited form or style of performance; and however rude or irregular this may be, that is the form in which the feeling will always, be expressed."
If this is true, mere surplus energy in the individual can not explain it. Of course the Lamarekian theory has no trouble with it. Its advocates can say with Hudson, " If all men had agreed at some period of race history to express the joyful excitement which now has such varied manifestation, by dancing a minuet, and if this dance had finally become instinctive, men would be in the same case that animals are in now." But Wallace is very sceptical about the inheritance of acquired characters, and takes special pains to refer instinct finally to natural selection.  Whoever agrees with him in this must cast aside his Spencerian theory of courtship, for it stands or falls with the Lamarckian principle. Once grant that there is no inheritance of individually acquired habits, and that choice by the female is not influential, then these phenomena, which are of too great importance to the. species to be dismissed as a mere discharge ûf surplus energy, however favour
(239) able that condition may be for them, must be referred at once to natural selection.
The case is quite different, as I have remarked, with the first element of Wallace's theory. Here the gifted author advances his original ideas and reaches conclusions which are calculated, in my opinion, to seriously modify the Darwinian theory of sexual selection. Taking, as an example, the parrot which is commonly of a green ground colour with stripes of yellow, red, and blue, Wallace would say that through adaptation to life in the woods the green colour serves as a defence, while the stripes are distinguishing marks for purposes of recognition, and we have brilliant plumage explained satisfactorily without any reference to sexual selection, which can not, then, have the range that Darwin attributes to it in accounting for the colouring and other ornamentation of animals.
Quite as convincing, too, is the argument against the exercise of aesthetic judgment, comparison, and selection in pairing. I am even inclined to go further than Wallace and exclude the conscious choice of even the strongest and bravest, which he seems disposed to admit, but I do not on that account imagine that the Darwinian hypothesis is refuted.
Going on to consider bird-songs, Wallace says
" The peculiar calls of birds, and even the singing of the males, may very well have originated merely as a
(240) means of recognition between the two sexes of a species, and as an invitation from the male to the female bird." These acoustic signals become very important when the members of a species live far apart, and are of especial service to migratory birds whose males first arrive at the destination and call to their mates to follow. The male that is distinguished for the " clearness, loudness, and individuality " of his song would succeed first in accomplishing this, and has thus an advantage that may be decisive in the struggle for life. But in that case the clearness, loudness, and individuality of his song would be a sufficient object for the operation of natural selection. A close examination of these citations shows, I think, that while they modify the Darwinian theory very considerably, they do not exclude it. It would, indeed, be absurd to affirm that all birdsongs originate in a conscious aesthetic and critical act of judgment on the part of the female. A conscious choice either of the most beautiful or the loudest singer is certainly not the rule, and probably never occurs at all. But is it not still a choice, though unconscious, when the female turns to the singer whose voice, whether from strength or modulation, proves most attractive? Even if the song is primarily a means of recognition or an invitation from the male, still the psychological effect must be that the female follows the songster that excites her most, and so exerts a kind of unconscious selection.
But this is essentially the Darwinian idea, since, though there is indeed no conscious aesthetic selection,
(241) a kind of unconscious choosing does take place which is in a peculiar sense sexual selection, for the female is undoubtedly more easily won by the male that most strongly excites her sexual instinct. That such a selection as this is difficult or even incapable of proof from its very nature is no argument against its existence.
Wallace says, indeed, that all the things a young man may do to make himself acceptable in the eyes of his beloved, while they do perhaps please her, have no influence in inducing her to accede to his wishes. But is this a fact? A conscious influence would scarcely be allowed to them, but will not a fine figure, good address, noble carriage, and even tasteful dress prove a powerful spur to unconscious choice? Will not the soldier in his handsome uniform be more acceptable than the same man in his working blouse? Has not the actor or the singer who has distinguished himself a better reception than a man quite his equal, but engaged in a commonplace business?
And now, putting aside everything that distinguishes man from the other animals, all our appreciation of intelligence and culture, all higher aesthetic influences, all considerations of a practical and material nature—conceive such a human race and suppose a condition of absolute free love with every spiritual ground for preference removed—must we not suppose that such (impossible) human beings left to the mere processes of evolution would become stronger and more beautiful in the course of a hundred or more generations?
I can not, then, admit that sexual selection is entirely subverted by Wallace's conclusions. If we accept his
(242) theory of bird-song, an involuntary selection based on the strongest sexual excitement takes the place of a choice of the most pleasing, and we may assume the like in regard to the other arts of courtship. Having conceded so much, we must also admit that the excitement may be augmented by the display of unusual colours and forms, making sexual selection influential upon these as well, but that it was prepared for by the factors introduced by Wallace, in a much more extended way than was understood by Darwin.
The Darwinian principle thus improved seems to me to be the only one in existence that has the least value as a working hypothesis. It can not, of course, be said to be as well established as is the principle of natural selection, but it is materially strengthened by the substitution of involuntary yielding to the strongest impulse for conscious aesthetic choice on the part of the female. It must be borne in mind, however, that such selection does not, as a rule, imply a direct rejection of less favoured suitors, but owes its chief effectiveness to the advantage it offers the favoured male in securing the earlier birth of his children.
As we are now on hypothetical ground, the following note may not be out of place in conclusion. Professor Ziegler, of Freiburg, says, in the course of a private communication, " Among all animals a highly excited condition of the nervous system is necessary for the act of pairing, and consequently we find an exciting playful prelude very generally indulged in." The germ of a still more far-reaching modification of the theory of sexual selection seems to me to be contained in this
(243) indisputable fact. In the first place, it is certain that in general before any important motor discharge there is apt to be a preparatory and gradually increasing excitement. A period of rapidly increasing irritation which causes various reflex movements generally precedes a wrathful onslaught, as angry dogs illustrate no less than Homeric heroes. While we find this introductory stage, which is easy of explanation physiologically, reduced to a minimum in the instinct for flight and in the spring upon prey, it appears to be at the other extreme in the courtship of many animals, for we find a long-continued preliminary excitation necessary, which presents strange peculiarities. This fact seems to me to suggest very strongly the probability that in order to preserve the species the discharge of the sexual function must be rendered difficult, since the impulse to it is so powerful that without some such arrest it might easily become prejudicial to that end. This same strength of impulse is itself necessary to the preservation of the species; but, on the other hand, dams must be opposed to the impetuous stream, lest the impulse expend itself before it is made effectual, or the mothers of the race be robbed of their strength, to the detriment of their offspring.
If this be granted, all the rest follows easily enough. The most important factor in maintaining this necessary check is the coyness of the female; coquetry is the conflict between natural impulse and coyness, and the male's part is to overcome flip latter. This is accomplished most easily by pursuit, and at last by what appears sometimes as violence, but probably is not really such, but only a necessary stage in the attainment of the requisite pitch of excitation. There are other means as well; for instance, scent in many animals, that is useful as a means of rec-
(244) -ognition, is a powerful agent here; contact, too, plays its part with most animals, as well as the regular love plays, such as dancing, flying, and singing.
And since with these is connected the display of brilliant colours and striking forms, the intensifying of performances that were perhaps originally intended to serve other purposes may help to overcome the female's reluctance.
In all this we have attempted to indicate the outlines of a view which would so transform the original Darwinian principle that if fully carried out we should have to consider it a new theory. Sexual selection would then become a special case of natural selection. If the point of departure for this idea be granted—namely, that the excited condition necessary for pairing, and also a certain difficulty in its execution, are both useful for the preservation of the species—we find the whole series of phenomena related to the subject so much more simply and satisfactorily explained that no one, it seems to me, can hesitate to decide in favour of the hypothesis. Instead of a conscious or unconscious choice, of which we know nothing certain, we have the need of overcoming instinctive coyness in the female, a fact familiar enough, but hitherto not sufficiently accounted for. Then the question is no longer which among many males will be chosen by the female, but which one has the qualities that can overcome the reluctance of the female whom he woos. How great a difference this is will appear from the fact that in the well-founded opinion of the Millers the choice itself, the betrothal of the birds, as it were, takes place before the breeding time. " Long before the springtime, with all its enticements
(245) to love, the young birds have chosen their mates, unseen by any but the closest observers. It is a common mistake to suppose that the marriage bond is first assumed in spring. Rather to this time belongs the male's first solicitations for his mate's consent to sexual union, and this has been falsely called pairing." If this opinion, so emphatically expressed, is correct, the explanation of the phenomena of courtship by means of conscious or unconscious choice is irretrievably damaged. Our view, on the contrary, would be in perfect accord with it, whether there had been a previous choice or none at all. Reproduction would be assured to the male who possessed the qualities and capacities necessary to conquer the instinctive reluctance of the mate.
This explains, too, why the dallying of birds that have lived in wedlock for a long time is repeated year after year, and indeed much oftener, although there can certainly be no further selection by the female.  And, finally, our hypothesis applies equally well to plays by masses and whole flocks together, and to those cases where the female takes part in the flying and singing, which present great difficulty to the Darwinian theory, and yet it does not preclude the possibility of a conscious or unconscious choice in Darwin's sense.
Before going on to the second part of our subject, I wish to notice the common objection that what we call the arts of courtship are frequently practised at other times.
This objection is expressed most clearly by Spencer,
(246) Wallace, and Hudson. One of the passages already cited from Wallace will serve as an example. He says that when there is a surplus of energy the animal indulges in all sorts of strange motions and vocal exercises. This happens, it is true, most commonly at the mating time, when the animal is in full possession of all his powers, but may occur at any time when there is superabundant vigour.
I have already pointed out that such a conception of hereditary instinct must to have any value be supported by the theory of the inheritance of acquired habits. Even Darwin, who concedes the Lamarckian principle, has expressed himself in opposition to the view that such phenomena may be regarded as expressing a general state of exhilaration, with only a secondary application to courtship. He quotes from an article and from letters of Job. von Fischer that a young mandril, when he saw himself for the first time in a mirror, turned round after a while with his red back toward the glass, just as many apes do when they see strangers looking at them. (Brehm quotes an ancient description of a mandril by Gesner: " This animal was brought to Augsburg with great wonder and exhibited there. On his feet he had fingers like a man's, and when any one looked at him he turned his back.") Other cases are recorded where the animal apparently desired to display what he considered his greatest beauties and attractions, just as these monkeys show to the observer their most highly coloured parts.
How shall we account for these facts? Can they be the effects of ordinary reflexes answering to any
(247) excitation? That is not likely with movements so significant. Or shall we say with Fischer that the reason monkeys enjoy being stroked or scratched on bare spots is because such sensations are associated with the friendly offices of comrades in removing thorns, etc., and from this their modes of greeting have developed? Is it not a thousand times more natural to suppose that such instincts are primarily for the purpose of sexual excitation, though they are sometimes connected with other stimuli? I do not think that any one can seriously doubt where the greater probability lies.
These remarks also apply to dancing, evolutions in flight, contortions of the body, erection of feathers, making strange noises, as well as the calling and singing of amorous animals. In all these we see instinctive acts performed for the purpose of arousing excitement, usually in both sexes. As the ape exhibits such actions most unmistakably, I have cited his case to avoid the possibility of misconstruction, for none can deny their connection with the sexual life, or attribute them to any ordinary excitement.
In order to arrive at a satisfactory position, however, on this question, we must occupy middle ground between the contestants. «'e must admit that in most cases the actual basis for the arts of courtship is to be found in general excitement reflexes, or even in those of quite a different origin. This basis consists partly in such reflex motions as result from any strong excitation, such as restless fluttering, running about, skipping, and trembling, and further in the reflexes that are commonly awakened in the face of an enemy, such as inflation, erection of hair or feathers, lifting the voice, etc. These are obviously the material from which Nature has derived the peculiar arts of courtship in all is
(248) their variety, and these arts, as we have seen, are then extended to occasions which have no sexual meaning.
But what is our justification for calling this play? If the adult bird practises his skill in flight and song out of season and simply from good spirits, that indeed is play, and the gambols and dallyings of young immature animals are as much play as their romping is.
But, apart from these, it is common to speak of the arts of actual courtship in the same way, and this fact requires some explanation, though I confess I can not find one that is entirely adequate. The fact seems to be simply that the evolutions of birds on the wing, their songs and dances, and their naive display of what adornments they possess, impress us as playful, and we have fallen into the habit of speaking about all animals in the same way. But who knows that a mistaken analogy has not led us far astray? When a skater sees his beloved on the ice he displays all his skill before her, and a good dancer does the same at a ball; a man in love actually walks straighter and dresses better, and the power of song has its uses, too, in human courtship. When all this happens, we say the man is playing a part, is trying to appear stronger, more skilful, better looking, more sympathetic, etc., than he really is, and even if all the conditions of our definition of play are not fulfilled we must consider his conduct in that light. But are we justified in extending the analogy to the animal world on such grounds as these? Certainly not, for apart from uncertainty of any far-reaching correspondence between human and animal life in their higher aspects, such a proceeding would involve the fallacy of comparing phenomena that are not even externally alike. To make them so, the amorous gentleman should lift his voice at the sight of his lady,
(249) should indulge in all sorts of capers and dances, and instead of the fingering of his beard merely it should rise on end of itself, etc. Since these things do not transpire, we are precluded from drawing any conclusion from human analogy as to the psychological significance of animal courtship.
In fact, there seems even to be a direct contrast. The youth desirous of showing off his good looks or skill in any art acts voluntarily, he consciously plays a part when that is necessary to his purpose. The animal, on the contrary, acts reflexly, following a blind propensity. His condition of excitation calls into activity certain motor tracks, and the animal obeys the impulse, unconscious that he is making a display of his attractions.
I have exaggerated this contrast purposely, to prove that such a crude dualistic conception of courtship as exhibited by men and animals is too much like the Cartesian view. But this statement of it requires modification, for, on the one hand, the young man playing the agreeable is not so entirely governed by reason as might appear, for blind propensity has as much to do with his actions as reflective choice has, and, on the other hand, the higher animals, and especially birds, exhibit such a degree of intelligence that I consider it nearer the truth to affirm than to deny a consciousness of selfexhibition in their displays of beauty and dexterity. There is, of course, between affirmation and denial the safe but fruitless position of the sceptic with his doubting shrug, bit T think it is more honest to meet the, question squarely and lay before the reader sufficient examples to justify an intelligent judgment upon the characteristics of a playful act.
The difficulty of definition is greater here than with other classes of play, for the reason that it is neces-
(250) -sary to get at the psychic or inner features of the phenomenon. We established as a fundamental principle of our inquiry the fact that play is, to state it briefly, not exercise of, but practice preparatory to, instinctive activity. When, as in the case of young animals, the practice is obviously preparatory, there is no occasion to speculate on the probable psychic accompaniments in order to establish its playful character. But here we are confronted with acts that are performed at the time for the actual exercise of the instinct, and consequently in their external manifestation appear as serious means to a real end. In such cases, therefore, only the psychic significance which I before put aside as a secondary consideration can decide as to the genuine playfulness of an act.
The bird performing his fantastic evolutions of flight and dancing before the object of his affections is not playing, so long as he only discharges the motor functions prescribed by heredity. Sexual excitement would produce the reactions necessary for courtship without anything taking place in the creature's mind other than takes place there when he involuntarily flies away at the sight of an enemy. All the complicated acts of courtship would then be nothing more than physiological results of excitation, a direct exercise of instinct for serious ends, not in any sense play. Familiar facts show that this may often be the case. It frequently happens that excitation unconnected with sex — such, for instance, as that produced by the sight of a foe—calls forth the manifestations usually associated with courtship, and not only those that might
(251) be calculated to inspire fear, such as erection of the feathers, etc., but even exhibitions of flight and singing. Canaries commonly trill shrilly while fighting, and Brehm says that the lapwing, which is very irritable during the nesting period, becomes wildly excited, sounds his mating call, and tumbles about in the air at the approach of a man or an animal. Since, then, the excitement of anger can produce these effects reflexly, it is probable that that of courtship may frequently act in the same way; indeed, among the lower orders this is probably the rule.
On the other hand, we are forced to remember that the acts of the higher animals are generally accompanied by quite complicated psychic processes. Taking birds again as our example, it must be conceded that an enlightened animal psychologist is obliged to attribute to them a highly developed intellectual and emotional life. " Adequately to treat of the intelligence of birds," says Romanes, " a separate volume would be required." And we know from many independent observations that are mutually confirmatory to a remarkable degree that this statement is not exaggerated. Pigeons recognise a voice after many months' absence, and a bullfinch belonging to one of the Mullers did so after nearly a year. Tame storks answer to a familiar name.  It is well known that birds dream, and parrots sometimes talk in their sleep; the emotions of love and sympathy are very active; the conjugal fidelity of many species speaks for the finer feelings, the wedded pair evincing the deepest grief on being
(252) separated and the greatest joy on reunion; crows, in spite of their shyness of a gun, hover about a comrade that has been shot instead of taking flight; parrots and storks revenge an injury after a long interval and rejoice diabolically over the success of a piece of mischief. The behaviour of peacocks and turkeys points to the conclusion that birds can be vain, but might be thought insufficient to prove it if it were not for the pride of talking birds over their accomplishments; Darwin has conclusively proved that they take pleasure in beautiful colours and musical sounds; many birds drop shell-covered prey from a height in order to break the shell; the teachableness of canaries, finches, and other birds is astonishing; they learn the most difficult compositions; crows have been known to conduct trials, where by common consent some unpopular members of the community were condemned and executed; swallows, in whose nest a sparrow has established itself, wall up the entrance so that the intruder perishes.
This list might be extended indefinitely, but these few examples, which I have purposely chosen as some of the most remarkable among well-authenticated cases, clearly indicate mental endowments of a high order in the birds concerned.
This being established, it must be admitted that the ardent male who performs his flyings and dancings again and again before his mate and invariably succeeds by such methods in overcoming her reluctance, may well be quite conscious of what he is doing. That satisfaction in his ability to talk, which the parrot shows so plainly, and which appears so early in the child, is probably akin to the feeling which swells the breast
(253) of a bird when he conducts his courtship successfully. And thus it may come about that the actual exercise of instinct for a real end may, to a certain degree, have the psychological aspect of mere play. Just as strong men sometimes undertake severe physical labour and derive pleasure from it—that pleasure in power which imparts a playful character to the most serious workso we may suppose the wooing bird enjoys his own agility and skill, nor can we deny to him the satisfaction that makes their exercise a play.
Thus the dance of courtship may be considered psychologically as having the character of a movement play, though it is not actually play in itself considered. Further, it seems to follow, from the admission that the female enjoys witnessing such blandishments, that the male must be conscious of giving her that pleasurethat is, is conscious that he is making a display—and in this, too, the act which is a serious exercise of instinct takes on the psychological aspect of play. Thus the crude dualistic contrasting of human and animal courtships is shown to be unwarranted.
Taking a general view of love plays, I distinguish five separate classes, as follows
1. Love plays among young animals.
2. Courtship by means of the arts of movement.
3. Courtship by means of the display of unusual or beautiful colours and forms.
4. Courtship by means of noises and tones.
5. Coquetry in the female.
1. Love Plays among Young Animals.
Among animals that have a period of youth the sexual instinct usually finds expression in some sort of play long before maturity. This is especially notice-
(254) able in mammals, some of which even in infancy make efforts to produce the movements necessary for pairing, a fact which can only be explained as practice for later life. Such phenomena are common among young dogs and apes, and Dr. Seitz, in Frankfort, noticed them in an antelope only six weeks old. While there are cases, especially among monkeys, where there is so much excitement as to render the playful character doubtful, still, as a rule, it is attributed to youthful sportiveness. According to Dr. Seitz, it sometimes happens in these games that the sexes change their parts, the male coqueting and the female pursuing. Chr. L. Brehm has noticed this, too, in the case of the golden-crested wren.
Much detailed material has been collected by ornithologists to show that songs, dancing, and flying evolutions are extensively practised by young birds in their first autumn, too early to serve the purposes of reproduction. This is genuine play, practice for instinctive activity quite as much as are the chasing and fighting of young animals. " The song of birds," says the elder Brehm, " appears to be the expression of love, for it begins with many shortly before pairing and ceases altogether after it, and with those that sing all through the summer, as the field lark does, the pairing season lasts as long. Caged birds are no exception to this, for most of them lose their natural or hereditary song or never acquire it, as, for instance, the wood lark, the red linnet, and many others.
" Awakening love impels some birds in captivity to
(255) sing as usual, and they also breed in that state, but the majority lose their power to do the latter and sing only as the effect of rich food and ennui. But the most noteworthy thing about the whole subject is that their love is awakened long before breeding time, usually in the first autumn of their lives. This fact has not been announced before, and should be supported by weighty proof, therefore I will now proceed to name the birds whose young I have myself heard singing in the autumn . . . . Young magpies (Corvus pica) produce in September, often in August and October as well, the long metallic notes that characterize them in spring, just before pairing . . . . 1 have often heard the Picus viridicamas piping in September as beautifully as in April, and indeed the Picus major sometimes hums in the autumn, picking absently meanwhile among the dry branches just as he does in spring. The crossbill and some woodpeckers sing before they have shed their first feathers. Young house and field sparrows not only chatter and chirp, but swell up their throats and peck at one another just as they will do at the pairing time next spring. Red linnets begin their song while still in their baby clothes, learn it perfectly while moulting, and even in winter, if the weather is mild, join in singing with their elders. The wood lark sings as soon as his first moulting is past, not only while at rest, but mounting aloft as in spring, floating about as he sings. All the titmouse family sing, the swamp titmouse producing exactly the note that accompanies breeding, and in October, 1821, I saw one approach his mate with all the manifestations that precede pairing in the spring, while she dropped her wings and spread her tail." Brehm goes on to mention similar sons and actions on the part of starlings, water wagtail, willow wrens, blackand heath-cocks, and a great variety of other birds, and says in conclusion: " The fact that pairing does not follow these demonstrations proves their dissimilarity to those of domestic fowls. The young cock is phys-
(256) -ically developed very early and ready for pairing in the first autumn of his life, but, with the exception of the crossbill, this is not the case with the birds that have been mentioned. The awakening of love seems to fill these little creatures only with a beautiful tenderness, which inspires them to express their joy in song and other demonstrations. Hudson tells us that many species of American woodpeckers engage in a kind of duet which is practised in their earliest youth. " On meeting, the male and female, standing close together and facing each other, utter their clear, ringing concert, one emitting loud, single, measured notes, while the notes of its fellow are rapid rhythmical triplets; their voices have a joyous character, and seem to accord, thus producing a kind of harmony. This manner of singing is perhaps most perfect in the oven bird (Furnarius), and it is very curious that the young birds, when only partly fledged, are constantly heard in the nest or oven apparently practising these duets in the intervals when the parents are absent; single, measured notes, triplets, and long, concluding trills are all repeated with wonderful fidelity, although these notes are in character utterly unlike the hunger cry, which is like that of other fledglings." 
It would seem, then, to be firmly established, among birds at least, that the arts of courtship are practised as youthful sport before the time for reproduction. In choosing the examples cited from Brehm I have intentionally included some that refer to flying and dancing motion, as well as to singing.
2. Courtship by means of the Arts of Movement.
Beginning with mammals, some of the examples cited of fighting dogs belong here as properly. The amorous dog, too, in contrast to the feline tribe, which does not seem to have any special courtship movements, indulges in what might almost be called a dance. The motions are like those with which he approaches an enemy, especially the stiff-legged gait, the rigid tail, and the erect carriage of his head. The fact that a vain dog will behave in the same way when allowed to carry a cane proves the consciousness of self-exhibition.
The stone marten proudly lifts his head at the approach of a female, his tail is curved, the limbs stiffened, the hair rises on his back, and his whole aspect suggests the utmost vigour. 
The fish otter tumbles and splashes around his chosen one in an extraordinary manner, during which performance his eel-like tail is in constant motion and the sinuous body is as often above as beneath the surface of the water.  The buck delights to follow a doe about until their breeding time in July or August, and, according to Diezel, the same thing is repeated in November, but this time without result." The following interesting description of the action of some antelopes is by Schweinfurth: "About five hundred paces from the road we saw a group of sporting antelopes. Their manner of playing suggested a marching procession
(258) with an invisible leader. They followed one another in pairs, forming circles in the shaded wood as if they were in an arena. Other groups of three or four stood by as spectators, or from time to time joined the circle. This went on until my dog disturbed and scattered the assemblage, but I had plenty of time to observe what I have attempted to describe. I believe that it was the breeding time of the animals, and for that reason they were oblivious of the approach of danger." Brehm says of the water rat: "Both sexes indulge in longcontinued gambolling before they pair. The male behaves very strangely. He turns so rapidly as to make a whirlpool in the water. His mate looks on with apparent indifference, but must secretly enjoy his exhibition, for usually when it is finished she receives him with favour." The whale in love "turns over on his back, stands on his head, lashing the waves with his tail, leaps up with his giant bride sportively above the water and performs other antics."
Observations on birds are exceedingly copious in this connection. Two kinds of motion can be distinguished among them, which though sometimes found in combination are quite unlike. I mean flying evolutions and dancing motions. Taking flight first, we have Brehm's description of the blue-throated warbler: " In sunny weather it tumbles about in the air and performs the strangest evolutions, plunging headlong downward it often turns a complete somersault, as Naumann says. Then mounting slowly upward once more he flies like a dose, with quick movements of the wings and apparently with no object in view." Azara, describing a small finch which he aptly named Oscilador,
(259) says that early and late in the day it mounts up vertically to a moderate height, then flies off to a distance of twenty yards, describing a perfect curve in its passage; turning, it flies back over the imaginary line it has traced, and so on, repeatedly, appearing like a pendulum swung in space by an invisible thread." Audubon thus vividly portrays the American night hawk: "Their manner of flying is a good deal modified at the love season. The male employs the most wonderful evolutions to give expression to his feelings, conducting them with the greatest rapidity and agility in sight of his chosen mate, or to put to rout a rival. He often rises to a height of a hundred metres and more, and his cries become louder and more frequent as he mounts, then he plunges downward with a slanting direction, with wings half open, and so rapidly that it seems inevitable that he should be dashed in pieces on the ground. But at the right moment, sometimes when only a few inches from it, he spreads his wings and tail and turning soars upward once more." The same authority describes the mocking bird as fluttering about his mate and regularly dancing through the air. The whitethroat leaves his perch in a tree top while singing, rises ten to twenty yards and lets himself fall, still singing, either fluttering in a slanting direction or, with folded wings, almost perpendicularly.
The reed bird, while his mate is sitting on the nest, flies up in the air diagonally and floats with his wings held so that they nearly touch over him. The wood lark mounts in the same way, constantly singing, and after describing one or more circles falls or plunges down and slowly returns to the tree from which he set out.
The siskin, crossbill, many kinds of pigeons, the lapwing, golden plover, and various other birds behave in a similar way at their breeding time. I close this part of the subject with Naumann's description of the snipe. In the pairing time "the male flashes like lightning from his place in the marsh, first on a slant and then winding upward in a great spiral to the sky. He goes so high that even on bright days only the strongest eyes can follow him. At this great height he floats about in circles and then shoots down perpendicularly to the ground with wings widespread and motionless."
The marked similarity in the evolutions of such various birds must have attracted the attention of any reader of this collection of examples, which might be enlarged indefinitely by the addition of numberless others of a like character. Especially noticeable is the practice of that bold flight upward and then the rapid or slow return; it is peculiar and yet so common that its explanation seems a riddle difficult to solve. May there not be something in the fact that such a movement shows the under side of the bird's body to his mate? The kite, however, is said to take her with him on his flight, and in that case shows more of the upper part of his body. Yet once granted the operation of the instinct, and we may easily assume that the bird's gliding downward through the air is a delightful movement play which must be about as much like our coasting on snow as travelling on rubber tires is like the jolting of a dray wagon.
Among storks and preying birds the female generally participates in these flights. " It is a noble
(261) sight," says Naumann, " and has a quality of stateliness when a pair of storks in fine weather and at the beginning of their pairing time, for then they seem to enjoy it most, circle up in the air higher and ever higher, and at the top of the gigantic spiral disappear in the clouds." Whole flocks of cranes make these circles together, when the weather is fine and they are not hurried. Falcons and ravens rise in pairs to a great height and describe noble curves. Crown Prince Rudolf, of Austria, thus describes the kite: " In the spring, at pairing time, some idea of their powers of flight can be formed. Exhilarated by the knowledge of their love, the pair mount high in the air and move in circles. Suddenly one or the other drops, with wings relaxed, almost to the water, skims along rapidly in broken lines for a short distance, then turns and hastens upward once more, shakes like the kestrel, and performs some wonderful evolutions." Naumann says, referring to the buzzard: " It is a treat to watch their gambols above their nest in fine weather, how the pair slowly circle upward without moving their wings, the male gradually outstripping his mate. He then lets himself descend from a great height with a peculiar vibratory motion of the wings, repeating this performance over and over for perhaps a quarter of an hour."
The other kind of movement play common among wooing birds is the dance performed either on the ground or among the branches of trees. If skill in flight serves to display the male's beauty and agility to his mate, dancing is better calculated to call attention to and emphasize brilliant colours and advantages of figure.
(262) I will cite only a few cases, selecting those in which the motions seem to me of an unmistakably exciting nature.
First I may notice the crane, which is one of the most intelligent of birds, for in its actions we can see clearly how genuine courtship may become playful.
To corroborate my statement about the intelligence of cranes I give this description: " Herr yon Seiffertitz had a crane that he captured when young and downy. He was allowed the freedom of the premises, and when he was a year old followed his master for long walks, separated quarrelling animals, went to pasture with the herds, drove in young cattle that strayed, turned away beggars, and quieted restive horses. When he was hungry he went to the window and called, and if his water was not fresh he threw it out and called for more. He had a special liking for the bull, visited him in his stall, kept flies off him, answered when he lowed, and accompanied him to the meadow, dancing about him at a prudent distance, and stopping now and then to make ridiculous bows. If his master scolded him, the crane stood in the most dejected attitude, with his head bowed down to the ground."  That an animal of such intelligence should dance purely to amuse himself is not at all surprising. Brehm says: " The crane delights, when in the mood for it, in vigorous leaps, excited
(263) gesturing, and strange positions. He twists his neck, spreads his wings, and regularly dances; sometimes he stoops repeatedly in rapid succession, spreads his wings, and runs swiftly back and forth, expressing in every possible way unbounded joyousness, but through it all he is always graceful, always beautiful." " The peacock crane stands on a sand bank and begins to dance at the slightest provocation, sometimes nothing more than the fact that he has stepped on a hillock. The dancer often springs as high as a metre from the ground, spreads his wings and sets his feet down mincingly. I do not know whether both sexes dance, but am inclined to think that it is only the male." Tame birds of this kind welcome their friends in a similar way. 
" Visitors to zoölogical gardens have probably noticed that the cranes begin to dance when the music strikes up." The one described above danced around his favourite bull. Another made the most ludicrous bounds before a mirror.  We can hardly doubt that the various movements described were originally connected with courtship, for they are such as characterize that period in the whole world of birds, but they have apparently become to the crane the expression of general well-being. And since he is so intelligent we may well suppose that he takes pleasure in going through them—that is, that he is playing.
The ostrich struts before his mate with wings unfurled and lowered, sometimes runs very fast, making
(264) three or four sharp turns with inimitable skill, then checks his pace and marches proudly back again, to repeat the sport.
According to Liebe's description of the lapwing, he does not go directly to the female after his exhibition of flying, but makes eyes at her in the funniest way, skipping now to the right, now to the left, and making deep bows with his head held on one side. " At this she will rise and stir about a little and begin a soft twittering which seems to delight her mate, who gives expression to his warmth of feeling by running a few steps nearer and standing while he throws a grass blade or bit of stone behind him, which seems to be the signal for beginning the game anew." Brehm says that the sportive heathcock " holds his tail upright and fan-shaped, his head and neck, on which the feathers are erected, outstretched, and drags his wings. He leaps from side to side, sometimes circles, and finally plunges his bill deep in the ground. The condor spreads his wings, bends his neck stiffly, and turns slowly with little tripping steps and trembling wings. " In North America," says Darwin, " 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 twenty feet in diameter, so that the ground is worn quite bare, like a fairy ring. In these partridge dances, as they are called by the hunters, the birds assume the strangest attitudes and run round, some to the left and some to the right."
I believe I am right in assuming that such dancing motions are not only the means of displaying the colours
(265) of the bird's plumage, but, independently of that, produce excitation. If a human example is allowable, the effect of throwing one hip forward is suggestive of what I mean. That the Greeks understood this is proved by the " line of Praxiteles," which gave to Greek sculpture a certain sensuous charm while preserving its chaste severity.
I pass by the lower animals, though an example given above from fishes seems to indicate that they, too, are playful during courtship. On the whole it seems probable, as I said above, that most of the " courtship arts " were simply excitation reflexes. Since they are influential in stimulating the female, they were favoured by natural selection and rendered constantly more powerful and complicated, until they became full instincts. This is true even in such exceptional cases as those of the butterfly and the spider. It is only to animals with a high degree of intellectual development that we can even hypothetically attribute pleasure in their movements for themselves, the wish to accomplish something, or the desire to make a display, in addition to the habitual reflexes of courtship, so that in the midst of the real exercise of instinct the voice of play would rise as a psychic overtone; or, as James would say, would form a psychic fringe. Such genuine play as that of youth it can not be.
3. Courtship by means of the Display of Unusual or Beautiful Forms and Colours.
After what has gone before, it is sufficient to say here that in this case, too, the display is playful only
(266) when the animal making it is intelligent enough to be conscious of self-exhibition. " With mammals," says Darwin, " the male appears to win the female more through the laws of battle than through the display of his charms," but he adds a long list of sexual stimuli. Nowhere, however, do I recall a description by him or another where a mammal attempted to draw attention to his excited condition by movements, with the single exception of monkeys. Indeed, Darwin says that proof is wanting that the males of mammals make any effort to display their charms to the female. 
But perhaps the actions described in the section on courtship arts, such as the dog's erect carriage, his waving tail and stiff legs, are partly to show his physical advantages, and we read how the stone marten raised his hair, and the fish otter played with his eel-like tail. I have often noticed, too, that dogs who wish to be especially friendly have a way of turning their back to the stranger, which is like the habit of the apes, for the dog often has striking tufts of hair on his hind parts.
We now take up birds again. All the different motions that we have seen described are useful to the bird in displaying his form and colouring. When the reed warbler takes his downward plunge in the air his feathers are inflated till he looks like a ball. The beautiful Madagascar weaver bird flutters like a bat, with trembling wings, about the modest gray female. Naumann says of the blue titmouse: "Hopping busily about in the bushes, swaying on slender sprays, etc., the male dallies with his mate, and at last floats from one tree top to another, sometimes forty feet away, where the
(267) widespread wings are not folded and all his feathers are so ruffled up that he looks much larger and is hardly recognisable. But he can not sustain a horizontal flight, and each time sinks perceptibly lower. This kind of floating is not usual with the titmouse, and therefore the more remarkable."
The hoopoe spreads his fine head decoration in flying as a fan is opened and shut. The striped snipe inflates his feathers and flies slowly with languid strokes, looking much more like an owl than one of his own kind.
The tumbling about in the air common with so many birds, as well as the upward flight and quick descent, also serves to show off their colouring. Dance motions are, however, best of all calculated to display their charms advantageously, and the vanity displayed by many birds during these performances strengthens the probability of self-consciousness. Indeed, when we reflect how early a child shows an appreciation of any expression of admiration, how vain the dog is of his tricks, and the parrot of talking, this supposition does not seem unwarranted. The vanity of peacocks is proverbial. " He evidently wishes for a spectator of some kind," says Darwin, " and, as I have often seen, will show off his finery before poultry, or even pigs."
Gesner remarked, long ago, in his Historia Animalism, that the peacock admired its own beautiful plumage and at once displays his glowing feathers when any one admires them and calls them beautiful. Bennett says the bird of paradise looks knowing and dances about when a visitor approaches his cage. He will not endure the least spot on his feathers, and often spreads his wings and tail to gaze upon his finery. " Espe-
(268) -cially in the morning does he try to display all his glory. He busies himself in arranging his plumage. The beautiful side feathers are spread out and drawn softly through his bill, the short feathers disposed to the best possible advantage and shaken lightly, then he raises the splendid long plumes that float like down over his back and spreads them as much as possible. All this accomplished, he runs back and forth with quick bounds, vanity and delight in his own beauty expressed in his every movement. He examines himself from above and below, and gives vent to his satisfaction in loud cries, that are, alas! only harsh noises. After each exhibition it seems to be necessary to rearrange his feathers, but this labour never tires him, and he spreads them again and again, as a vain woman would do."
Let us now notice some birds during courtship itself.
The male Rupicola crocea, says Darwin, is one of the most beautiful birds in the world, of a splendid orange colour, and with finely shaped and marked feathers. The female is a greenish brown with red shading, and has a very small comb. Sir R. Schomburgh has described the wooing of these birds. He happened upon a rendezvous where ten males and two females were present. A space of about four or five metres in diameter was cleared as if by human hands, and every blade of grass removed. One male danced to the evident delight . of the others; he stretched his wings, raised his head, and spread his tail like a fan, strutting proudly till he was tired and then was relieved by another.
Sometimes a dozen or more birds of paradise collect in full feather, where they hold a " dance meeting," as
(269) the natives call it. They flutter about, spread their wings, erect their splendid plumes, vibrating them till, as Wallace remarks, the whole tree top seems made of waving feathers.
Pheasants not only spread and erect their fine crests at such times, but they turn sideways toward the female on whichever side she happens to be standing, and incline the beautiful outspread tail in the same direction. When a peacock wishes to make a display he stands opposite the female, spreads his tail and raises it perpendicularly, at the same time showing to advantage his beautiful neck and breast. Those, however, that have dark breasts and eye marks all over the body display their tails a little diagonally and stand in such a position that the eye marks are clearly seen by the female. In whatever direction she turns the outspread wings and tail held diagonally always confront her.
It seems undeniable that there is in this kind of courtship a conscious display of personal charms, and therefore play.
Following Darwin's account, we now turn to birds of more sober plumage. The bullfinch approaches his mate from the front, inflating the brilliant red feathers on his breast so that they are much more conspicuous than usual, and twisting his black tail in a comical manner. The common linnet inflates its rose-coloured breast and spreads its brown wings and tail, showing the white border to the best advantage. The goldfinch behaves differently from other finches. His wings
(270) are fine; black shoulders with dark pointed quills picked out with white and gold. Weir confirms Darwin's statement that no other British finch turns from side to side as he does in courtship, not even the close-related siskin, for it would not enhance his beauty. The common pigeon has iridescent breast feathers, and there fore inflates them, but the Australian pigeon (Ocyphaps lophotes), that has handsome bronze wings, acts quite differently. Standing before the female he sinks his head almost to the ground, raises his widespread tail, and half opens his wings, then he lets his body rise and fall with a slow motion that causes the glittering feathers to shine brilliantly in the sunshine.
Karl Muller tells us that the red wagtail prostrates himself at the feet of his bride, flapping his wings and dragging the outspread fan of his tail on the ground. The crossbill perches on the highest limb of the tallest tree, singing lustily and whirling about incessantly the while. The snipe ardently draws near his mate with inflated feathers, lowered wings, and tail raised and spread. When the cuckoo feels the stirrings of love he " inflates his throat feathers, hangs his wings, moves his partly spread tail up and down, turns from side to side and bows to his lady as often as he cries 'Cuckoo." The orange bird pursues his mate in apparent wrath and then bows and scrapes before her. Brehm describes the pairing of golden-crested wrens very beautifully: " The male inflates his crest until it forms a splendid crown, in which the black stripes extend far down the side of his head without concealing the white eye marks and displaying the flame-coloured parting most advantageously." 
Even if one fully agrees with Mr. Wallace that sexual selection does not actually create the beauty of bird plumage, it is hardly possible in the face of facts like these to deny that at least those developments of colour and other ornamentation which transcend the uses of concealment and warning must have some connection with the sexual life. The substitution of unconscious for conscious choice makes this connection clearer, but the acceptance of the theory herein previously developed—namely, that of the importance to race life of feminine coyness and the necessity on the part of males to overcome it by such means—does away with all choice, and relegates the whole subject to the sphere of natural selection.
4. Courtship by means of Noises and Tones.
Here, too, the view set forth in the last section is applicable. The ordinary sounds emitted by the excited male probably have the same effect as the husky voice and laboured breathing of civilized man. They furnish material for the working of selection in the production of courtship arts which are later used also for other purposes. Among the higher animals imitation often plays a part as important as that of selection—indeed, it some-times supplants the latter in cases where hereditary courtship arts are rudimentary only, each individual acquiring the finer points by imitation. We may suppose, for example, that many young birds learn from their elders that they must fight for a mate, anal in turn teach it to the next generation. By this method an art would be acquired founded on an instinctive basis, but not in
(272) herited by the individual—similar, cum grano salis, to the fine arts of savages. For by outgrowing instinct they reach, through teaching and imitation, a certain degree of development to which they remain constant so long as the conditions remain constant, but would at once fall back to the level of hereditary instinct were the individuals to lose their model. The more important the part play by imitation, the more probability of a playful expression of the activity in question.
I again pass over the lower orders, although they offer much that is of the greatest interest. There is very little that deserves to be called vocal art in the courtship of mammals; most of them confine their acoustic demonstrations to a passionate howl, roar, shriek, or growl, or to the simple call. The performance of howling apes, however, is a notable exception, for they collect in companies and frequently give concerts that last for hours. Hensel says: " In summer, when the beams of the morning sun have dispelled the night mists, the howling apes leave the shelter of the thickly leaved trees to which they have clung all night. After satisfying their hunger they have time before the heat of the day to indulge in social pleasures which, as befits animals so serious, are free from the unseemliness that characterizes those of many of their relations. They now repair to the shelter of some gigantic monarch of the forest whose limbs offer facilities for walking exercises. The head of the family appropriates one
(273) of these branches and advances along it seriously, with elevated tail, while the others group themselves about him. Soon he gives forth soft single notes, as the lion likes to do when he tests the capacity of his lungs. This sound, which seems to be made by drawing the breath in and out, becomes deeper and in more rapid succession as the excitement of the singer increases. At last, when the highest pitch is reached, the intervals cease and the sound becomes a continuous roar, and at this point all the others, male and female, join in, and for fully ten seconds at a time the awful chorus sounds through the quiet forest. At its close the leader begins again with the detached sounds." How can we explain this strange concert? This description gives the impression that it is merely a social game, but how did the animal acquire the instrument on which he plays, the throat thickened as with a gôitre? A. von Humboldt says: " The small American monkey chirps like a sparrow, having simply an ordinary hyoid bone, but that of the great ape is a large bony drum. The upper part of the larynx has six compartments, in which the voice is formed. Two of these compartments are nest-shaped and very like the lower larynx of birds. The doleful howl of the ape is caused by the air streaming through this great drum, and when we see how large an instrument it is we are no longer surprised at the strength and range of this animal's voice, or that it gives him the name he bears." Such a structure as this must serve some useful purpose, and the idea of courtship suggests itself as the probable us in the fir, t instance, since it outweighs all other causes for excitement. Then its exercise may have come by association to be purely playful.
Scheitlin says of the cat: " Their pairing time is
(274) interesting. The male is coy, the females who visit him sit around him while he growls in a deep base. The others sing tenor, alto, soprano, and every possible part as the chorus mounts, constantly growing wilder. They shake their fists in one another's faces, and will not let even him whom they have come to visit approach them. On clear moonlight nights they make more noise than the wildest urchins." This certainly seems something more than mere sportiveness, and must unquestionably be set down as connected with courtship. Darwin regards the cry of the howling ape in the same light, and in addition has this to say about 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 I do not doubt that a good violinist would be able to give a correct idea of the gibbon's composition, excepting as regards its loudness.' This gibbon is not the only species in the genus which sings, for my son, Francis Darwin, attentively listened in the zoölogical gardens to a Hylobates leuciscus which sang a cadence of three notes in true musical intervals and with clear musical tones. It is a more surprising fact that certain rodents utter musical sounds. Singing mice have often been mentioned and exhibited, but imposture has commonly been suspected. We have, however, at last a clear account by a well-known observer, the Rev. S. Lockwood, of the musical powers of an American species, the Hesperomys cognates, belonging to a genus distinct from
(275) that of the English mouse. This little animal was kept in confinement, and the performance was repeatedly heard. In one of the two chief songs `the last bar would frequently— be prolonged to two or three, and she would sometimes change from C sharp and D to C natural and D, then warble on these two notes a while and wind up with a quick chirp on C sharp and D. The distinction between the semitones was very marked and easily appreciable to a good ear."
Coming again to birds we first note their characteristic song. Brehm and Lenz tell us of finches
" Their song is called a strophe because it consists of one or two rhythmic measures, given with great persistence and sometimes with rapidity. To this the finch owes its popularity among fanciers, who distinguish a great number of such strophes and give them each a name until their study has become quite a science, involved in much mystery to the uninitiated; for while there is little difference between them to the unpractised ear, these people distinguish twenty or more distinct strophes. According to Lenz, one kind of snipe has nineteen strophes when he is free. The syllables of a good double strophe are as follows: Zizozozizizizizizizizirreuzipiah tototototototozissskutziah. The nightingale's song contains from twenty to twenty-four distinct strophes, and according to Naumann's fine description, " is characterized by a fulness of tone, a harmony and variety that are found in the song of no other bird, so that she is rightly palled the queen of songsters. With indescribable delicacy, soft flutelike notes alternate with trembling ones, melting tones with those that are joyful, and melancholy strains with ecstatic outbursts. If a soft note begins
(276) the song, gaining in strength to the climax and then dying away at the end, the next strophe will be a series of notes given with hearty relish, and the third a melancholy strain melting, with purest flute notes, into a gayer one. Pauses between the strophes heighten the effect of these enchanting melodies; they and the measured tempo must be noted, fully to comprehend their beauty. We are amazed at first at the number and variety of these bewitching tones, then at their fulness and power coming from a creature so small. It seems almost a miracle that there can be such strength in the muscles of its tiny throat." Beckstein has attempted to write the syllables of its strophes thus :
Spe, tiuu, squa,
Tio, tio, tio, tio, tio, tio, tio, tix,
Qutio qutio qutio qutio,
Zquô zquô zqub zquô,
Tsü, tsü, tsü, tsü, tsü, tsü, tsü, tsü, tsü, tsi.
Quoror, tin, zqua, pipiqui,
Zorre, zorre, zorre, zorre hi;
Tzatn, tzatn, tzatn, tzatn, tzatn, tzatn, tzatn, zi,
Dlo, dlo, dlo, dlo, dlo, dlo, dlo, dlo, dlo,
Quio tr rrrrrrrr itz
Lü Iii Iii, ly, ly, ly, lî lî lî,
Quio, didl li lulyli.
Ha gürr, gürr, quipio!
Qui, qui, qui, qui, qi qi qi qi, gi gi gi gi;
Gollgollgollgoll gia hahadoi,
Quigi horr ha diadiadillsi !
Quia, quia, quia, quia, quia, quia, quia, quia ti:
Qi qi qi jo jo jo jojojojo qi — Lü ly li le lä la lö to didl jo quia
Higaigaigaigaigaigaigai gai gaigai,
Quior ziozio pi.
Thrushes, unlike most birds, sit still when they sing, and the songs, too, have a soothing quality. They choose the summit of tall trees for their perch, as if to avoid interruption.
The song of the blackbird that perches, on fine evenings, on the topmost gable of a roof or the very highest branch of a tree and lifts his deep and yet clear and joyous voice is perhaps the most msthetically effective of all. Audubon says of the cardinal bird: "His song is at first loud and clear and suggestive of the best tones of a flageolet, but it sinks lower and lower until it dies away entirely. During his love time this noble singer produces his notes with more force, and seems conscious of his strength; he swells his breast, spreads
(278) his scarlet tail, flaps his wings, and turns from side to side as if he would express his joy in the possession of such a voice. Again and again the song is repeated, the bird only pausing to get breath." Brehm relates of the whistling and the scarlet shrike: " The most remarkable thing about these birds is undoubtedly the use they make of their song, which is, properly speaking, not a song at all, being but a single strain, sonorous as few often repeated notes are, and common to the two sexes. The call of the former consists of three, rarely two, distinct sounds, pure as a bell and all within the octave, beginning with a moderately high note, followed by a deeper one, and concluding with one still higher. These, like the piping of the scarlet shrike, are peculiar to the male bird, but his mate answers at once with an unmusical cackle or chick which is difficult to imitate or describe. The female scarlet shrike only begins her cackle when her mate has finished his call, but the whistling shrike usually joins him on the second note, but both show a surprisingly quick ear, and never keep him waiting. Sometimes she cackles three or four or even six times before the male joins in, but when he does so the whole performance begins over and proceeds in regular form. Several experiments have proved to me that the two sexes always act together. I have killed now a male and now a female to make sure. When either falls and is, of course, silenced, the other anxiously repeats the call several times." The Prince von Wied says: " The bell bird, both by reason of its splendid white plumage and its clear, loud voice, is one of the attractions of a Brazilian forest, and is usually noticed at once by a stranger. His cry resembles the tone of a very clear bell, sounded once and then withheld for a long interval, or at times
(279) repeated rapidly, in which case it is like a blacksmith's strokes on the anvil." 
Brehm carefully observed one of these bell birds in captivity, and describes minutely its wildly excited condition, which becomes more and more intense as the cries are repeated: " That he sometimes even seals these love transports with his death is proved to me by the fact that the bell bird which I was watching fell dead from his perch with his last cry." One can hardly say in this case that the birds sing from mere exuberant spirits. Other birds show similar ecstasies, notably the black and heath cocks. The voice of the former is exceedingly high and is indescribable in words; their cry is well known to hunters and is commonly heard in the spring. About sundown this bird perches on a tree, preferably an old beech or fir, that he will return to year after year if not disturbed. At the time when the red beech leaves he sings with only short intermissions from the first gleam of dawn till after sundown. He takes his post on a bare, sturdy limb, inflates his long neck feathers, makes a wheel of his tail, drops his wings, erects his plumage, trips on his toes, and rolls his eyes comically. At the same time he gives forth notes that are at first slow and detached, then quicker and more connected, until at last a distinct beat can be distinguished among the accompanying notes, ending in a long-drawn cry, during which the bird rolls his eyes in ecstasy." 
I need not multiply these examples. Enough has been said to show that birds invariably sing during their mating time, but not exclusively then. The blackcock, starling, and robin also sing out of this season, as well as the water ouzel, which Tschudi has so beautifully described, while the wren, red linnet, and goldfinch can be heard all winter; the white-throat, too, sings all the year round. Indeed, it may be that the breeding time of some birds is variable, as seems to be the case with the water ouzel, which, Tschudi says, "does not confine itself to any particular month; the young just hatched may be seen even in January." Besides, birds sing not only before pairing but all through the breeding time; in numberless cases the male pours out his sweetest song while his mate is on the nest. This is obviously play, rather than courtship. The duets that they sometimes produce together are probably the effect of heredity; while in other cases the male song is taken up by imitation on the part of the female. Hudson says that a singing female usually has plumage the same as her mate. Finally, there are rare cases where the male sings better at other times than during his courtship. Spencer, in his article " On the Origin of Music," says this is true of the thrush.  And Hudson says of a small yellow finch found in La Plata that in August, when the trees are blooming, a flock of these birds will appear in a plantation, perching on the boughs and beginning a concert in chorus, " producing a great
(281) volume of sound as of a high wind when heard at a distance," and this takes place daily for hours at a time. But during his courtship the male has but " a feeble, sketchy music," regaining his skill only after the nest is built. This is a more valuable example than Spencer's, for he observed only a single bird that may have been sick at the time for pairing, while Hudson's observation refers to a whole species. Yet the phenomenon is too rare to have any weight against the overwhelming mass of evidence for the view that song in general belongs to courtship. It is wiser to seek some special explanation of these irregular cases, and also to bear in mind that " better " and " worse " are relative terms. A song broken by the restless motions of an excited bird may seem not so good to the listener as the same strain produced when the singer is quiet and his notes are therefore louder and more continuous. There is also a possibility that song is sometimes supplanted by the disproportionate evolution of other courtship artsthe finch spoken of by Hudson has unusual powers of flight and skill in dancing. However, I do not profess to find an adequate answer in these suppositions to this undeniable difficulty.
Those instances in which the bird expresses his excitement by means of a kind of instrumental music, instead of doing it vocally, are also very remarkable. Darwin has a long series of such examples. Peacocks rattle the quills of their tails, and birds of paradise do the same thin, during their courtship. Woodpeckers call the females by striking [lie bill very rapidly on dry wood, making in this way a sort of drumming sound. Turkeycocks scrape their wings on the ground. Many birds make a kind of whirring sound in flight; a familiar instance is the " beating " of army snipes as they mount
(282) rapidly aloft in the evening. It is evidently a call to the female, who answers from the earth with a " dickkiih " or " kip ti küpp ti küpp."
Naumann thought the flapping of storks connected with courtship, but as I do not consider these manifestations playful I abstain from further citations, except in the case of the bittern, which may be said to practise his art playfully if the following description is to be trusted. Brehm says: " The peculiar pairing call of the male bittern is like the lowing of oxen, and on still nights may be heard at a distance of two or three kilometres. It is composed of a prelude and a principal tone, and sounds something like ` 'Ueprumb'  at a distance. It is said that on coming near the birds a sound like beating on water with sticks is heard . . . . The male keeps it up almost constantly; beginning at twilight he is most vociferous before midnight, and ceases at dawn, only to start up again, however, between seven and nine o'clock. The observations of Count Wodzicki have confirmed the account of the older writers. He says: ` The performer stands on both feet with his bill in the water when giving vent to this extraordinary sound, which causes the water to spurt up all around. First I heard Naumann's 'Ue' and then the bird raised his head and looked behind him, but quickly plunging it in again he produced such a roar that I was startled. I am convinced that these tones which
(283) are loudest at their beginning are produced when the bird has his throat full of water and expels it with great force. The music went on, but he did not throw his head back again, nor did I hear the loud note any more. It seems to express the highest pitch of excitement, and having given vent to it he is relieved. After an interval he cautiously raised his bill from the water and peered around, for it seems that he can not tear himself away from his charmer." The bittern stands in an open space, where the female can see him during his performance. The splash is caused by his striking the water several times with his bill before plunging it in; other water sounds are produced by the falling drops, and the last one by the emission of what remains in his bill. A male disturbed by Wodzicki flew off and spurted out a considerable stream that had collected in this way."
5. Coquetry in the Female.
I have attempted, in the theoretical part of this chapter, to show that the instinctive coyness of females is the most efficient means of preventing the too early and too frequent yielding to sexual impulse. A high degree of excitement is necessary for both, but the female has an instinctive impulse to prevent the male's approach, which can only be overcome by persistent pursuit and the exercise of all his arts. This coyness often seems like fear, and sometimes even like anger, as in the case of spiders and preying animals, but sometimes there is no fear at all, the animal even inviting the male's approach until he shows some eagerness, then
(284) her coquetry manifests itself in alternate calling and fleeing. It is not essentially playful, for it is a struggle between opposing instincts and has a serious object, but we can easily see how it becomes play when unconnected with the strong emotions of fear or anger—that is, when it is a sort of kittenishness. Then the flight and resistance of the female, though they are not play pure and simple, take on something of the character of a game and temper the rough force of instinct.
As adequate descriptions of such playful coquetry are rare, I have only a few examples from the higher animals. The Müllers describe as follows the gambols of a pair of squirrels: " The male comes near and flees, grunts and whispers, runs and leaps, approaches his mate and leans against her; she turns away and lures him on, appears indifferent and then tries to please him, changes from momentary anger to frisky good humour; the bounds and chase go on so rapidly that one can scarcely follow their turns, and finds himself charmed by the sight of this artless sportiveness, as graceful as it is beautiful." " Another exquisite game may be seen in April and May, when the pairing watershrews carry on their teasing chase. The fleeing female pretends to hide, crouching in mole holes and under stones, roots, and rubbish while her mate looks for her. Or she skips out, throws herself in the water, runs across on the bottom and clambers to a new place on the other side of the brook; but he soon spies her and follows in her footsteps. So the game goes on, with only rest time enough for them to eat in." 
The doe, in her breeding time, calls to the buck in clear tones that bring him to her side at once, then she,
(285) " half in coyness, half in mischief, takes to flight at his eager approach, makes toward an open space, and runs in a circle. The buck naturally follows, and the chase grows hot and as exciting as a race of horses on a track. To the frequent high calls of the fleeing doe are added the deep, short cries of the panting buck; but suddenly the roguish doe disappears like a nymph into the thicket near at hand, and the baffled buck stands with head erect and ears thrown forward; then we see his head lowered as he catches the scent, and he too vanishes in the wood."
It is a familiar fact that female birds must be long courted and pursued before they yield. L. Büchner has collected some examples proving this. Mantegazza says: " Coquetry is not the exclusive prerogative of the human female. N o woman ever born could surpass the abominable ( !) refinement of cruelty displayed by a female canary in her pretended resistance to her mate's advances. All the countless devices of the feminine world to hide a Yes under a No are as nothing compared with the consummate coquetry, the deceptive flights, the bitings, and thousand wiles of female animals."
However mistaken the conclusions here drawn from this antagonism of sexual impulse and coyness, the fact undoubtedly remains that coquetry is exceedingly widespread among birds. Thus the female cuckoo answers the call of her mate with an alluring laugh that excites him to the utmost, but it is long before she gives berself up to him. A mad chase through tree tops ensues, during which she constantly incites him with that mocking call, till the poor fellow is fairly driven crazy.
The female kingfisher often torments her devoted lover for half a day, coming and calling him, and then taking to flight. But she never lets him out of her sight the while, looking back as she flies and measuring her speed, and wheeling back when he suddenly gives up the pursuit. The bower bird leads her mate a chase up and down their skilfully built pleasure house, and many other birds behave in a similar way. The male must exercise all the arts that have been described in these pages and more before her reluctance is overcome. She leads him on from limb to limb, from tree to tree, constantly eluding his eager pursuit until it seems that the tantalizing change from allurement to resistance must include an element of a mischievous playfulness.