Seite - 511 - in The Origin of Species

this theory. How strange it is that a bird, under the form of a woodpecker, should prey on insects on the ground ; that upland geese which rarely or never swim, should possess webbed feet; that a thrush-like bird should dive and feed on sub-aquatic insects ; and that a petrel should have the habits and structure fitting it for the life of an auk ! and so in endless other cases. But on the view of each species constantly trying to increase in number, with natural selec- tion always ready to adapt the slowly varying descendants of each to any unoccupied or ill-occupied place in nature, these facts cease to be strange, or might even have been antici- pated. We can to a certain extent understand how it is that there is so much beauty throughout nature; for this may be largely attributed to the agency of selection. That beauty, accord- ing to our sense of it, is not universal, must be admitted by every one who will look at some venomous snakes, at some fishes, and at certain hideous bats with a distorted resem- blance to the human face. Sexual selection has given the most brilliant colours, elegant patterns, and other ornaments to the males, and sometimes to both sexes of many birds, butterflies, and other animals. With birds it has often ren- dered the voice of the male musical to the female, as well as to our ears. Flowers and fruit have been rendered con- spicuous by brilliant colours in contrast with the green foli- age, in order that the flowers may be easily seen, visited, and fertilised by insects, and the seeds disseminated by birds. How it comes that certain colours, sounds, and forms should give pleasure to man and the lower animals,—that is, how the sense of beauty in its simplest form was first acquired,— we do not know any more than how certain odours and flavours were first rendered agreeable. As natural selection acts by competition, it adapts and improves the inhabitants of each country only in relation to their co-inhabitants; so that we need feel no surprise at the species of any one country, although on the ordinary view supposed to have been created and specially adapted for that country, being beaten and supplanted by the naturalised pro- ductions from another land. Nor ought we to marvel if all the contrivances in nature be not, as far as we can judge,