But, from what must be the dominating point of view in this work, it is by no means unnecessary to disentangle the confusion between æsthetic appreciation and physiological stimulation. The æsthetic corollaries, which are the most important in this connection, will be greatly modified as soon as the more physiological interpretation is applied to the various manifestations of animal art. When Darwin chose to endow the hen with an aboriginal æsthetic judgment he was at once confronted by a difficulty which was perhaps even greater than that of locating the beginnings of art in the animal kingdom. The facts compelled him to admit that in some species this æsthetic judgment seemed to be a very bad one indeed.[297] When secondary sexual characters are regarded as signs by which the kind and sex of the males are accentuated, this apparent inconsistency is easily understood. The harsh cry and the inharmonious colouring of the macaw[298] tell their tale as eloquently and convincingly as any of the æsthetic characters of the other birds. The roaring of the battle bump,[299] the disagreeable miauling of the peacock, and the bleating call-note of the greenfinch[300] no doubt cause as great a pleasure in their respective hens as is ever caused by the song of the nightingale in his mate. That the secondary sexual characters of the birds on the whole are so much more beautiful than those of the mammals is not the result of any originally higher standard of beauty with their respective females. The superiority of the birds is quite sufficiently accounted for by the peculiar conditions of their life, which necessitate and call forth graceful shape as well as graceful movements. Their gorgeous colouring, on the other hand, is undoubtedly—as has been shown above—to some extent at least conditioned by the gaudy colouring of the tropical landscape. It must be remarked, moreover, that notwithstanding their undeniable splendour, the dresses of the birds by no means generally fulfil the claims of tasteful composition. When appreciating the plumage and the songs of the birds, we usually look upon them as pieces of nature. We admire them as we admire the woods and flowers and every other manifestation of nature and life. This attitude must necessarily be given up as soon as a conscious tendency is assumed in “animal art.” When we regard the secondary sexual characters in the manner of Darwin—as results of an æsthetic choice—we cannot help missing all the æsthetic qualities of harmony and composition, which are never expected, and therefore never missed, in the objects of nature. If the proper distinction between art and nature is maintained, it will be possible to combine an unabated admiration for the marvels of beauty in bird life with a denial of “animal art.” CHAPTER XV ART AND SEXUAL SELECTION