From the evidence in hand we judge then that it is certainly not necessary to call in the feeling of the beautiful as the motive in the origin and development of sexual characters in animals and plants. Just as there is a cry of fear or a tone of anger there is a vocal expression of sexual feeling and emotion which has its use and is recognised as such, but whose æsthetic quality is no more a matter of immediate apprehension than in other utilities. At least the safest interpretation that we can now make for all the lower grades of sexuality is that sex characters are not primarily determined by the feeling for beauty, but are simply immediate signs of sex to awaken the sexual response and secure the best mate. How is it that sexuality is so prominent in expression among some species and so little among others?—compare peacocks and blue jays—is a question on which we have no light. We are also in ignorance how the particular sexual character was evolved and not some other, for example, why is not the peacock’s tail red? Grant Allen’s suggestion that food selection has influenced sex selection may be true, but it would require a very wide and thorough investigation. Do brilliant-hued birds prefer brilliant-hued foods? How is the coloration of the scarlet tanager related to the coloration of its food? However, if the colouring of foods and mates were the same, it would in some cases lead to disadvantageous confusion, and on general principles we should expect such distinct elements as nutrition and sex to develop on very different lines. The cue for colour may be learned first with reference to food, but it may be carried on as sexually significant on very distinct lines. Still to distinguish a food or a mate by colour is equally non-æsthetic in itself. At least we think it improbable that æsthetic psychosis arises as incentive to or reflex of sexuality in any of the lower psychic stages.