a daisy, the wing of a butterfly, the tail-covert of a peacock, such gradual merging of tint in tint could hardly fail to occur spontaneously, as a product of evolution; while the comparatively definite marking off of special spots or lines, as in some orchids and other flowers, could only present itself as a result of very intense competition between species, carried on under highly complex conditions. The views set forth by Mr. Bates upon the progressive modification of patches or regions in a butterfly's wing, and by Mr. Darwin and Mr. Wallace on the feathers of the peacock and the Argus-pheasant, though widely differing as to the particular mode of their evolution, yet alike convince us that the inevitable result must be just such a graceful running together of contiguous colors as we actually find to obtain in every case.
Lastly, we arrive at the sensibility to form, symmetry, arrangement of patterns, and the like higher sensuous aesthetic feelings, which remains in the eyes of many the chief stumbling-block in the way of accepting the theory of sexual selection. The pleasure derived from sweet tastes and fragrant perfumes is so purely sensuous that nobody doubts its universal existence among all the higher animals. The pleasure derived from musical sounds and bright colors, though more intimately bound up in the human consciousness with intellectual and higher emotional elements, yet contains so large a factor of mere sensuous stimulation that we can easily conceive of it as appealing to the ears and eyes of insects and vertebrates. But the still higher pleasure derived from graceful curves, symmetrical ornamentation, and elaborate tracery is so largely made up of intellectual feelings, and so largely supplemented in our own case by associations of costliness, human handicraft, or imitative skill, that we find it hard at first sight to believe in the existence of similar feelings among pheasants of the Indian jungle, antelopes of the African plains, or monkeys of the Brazilian forest. Even here, however, a little consideration may convince us that the æsthetic appreciation of form and its connected varieties is not necessarily above the narrow intellectual faculties of the higher vertebrates and articulates at least.
In the first place, if we look at the human race itself we shall find that a comparatively high susceptibility to form occurs even among very low races. Indeed, most exquisite patterns are produced by savages whose taste in color is apparently far less developed than that of parrots, humming-birds, and fruit-pigeons. The tattooed tracery of the Polynesians and many other savage tribes presents beautiful designs of which even a European decorative artist need not be ashamed. The New Zealand canoes, the paddles and clubs of the Admiralty-Islanders, the shields of the Zooloos, are all most graceful in their shapes and most daintily wrought with interlacing patterns in carved work. Calabashes, cocoanuts, ostrich-eggs, and other early vessels are always cut in sections which exactly coincide with the demands of the most
