and psychic. They give color and beauty and music to the lower orders, and all of these, as well as poetry, romance and idealism, to human life. The gorgeous feathers of the peacock, the majestic mien of the lion, the vocal excellencies of the nightingale, are all the hall-marks of sex in the marvelous handiwork of nature. And, of course, all of these features have their analogies in human life.
Besides the purely ornamental and vocal phases of secondary sex expression, it is also quite universal among animals to display other evidences of the chemical activity that is taking place within them. After all, the mating urge, pubescent development and all other aspects of sexual phenomena, are primarily manifestations of the body's chemistry, consisting principally of the secretions of the ductless or endocrine glands, and their reactions upon the various organs, tissues and the nervous system.
Animals, therefore, show many characteristic forms of sexual interest that are sexual in a secondary manner only. Thus, they disport themselves in various striking poses, contort their bodies in mid-air, hop or dance, spread the plumes of their tail-feathers for the approbation of the opposite gender of the species, and in other ways show a seeming consciousness of exercising a deliberate sex appeal. I say "seeming consciousness," because these actions are purely instinctive, spontaneous and automatic, and as involuntary as the changing of the color of their feathers, fur or hair. The frolicking animals just cannot help themselves. They are expressing themselves, not as their consciousness wills or or chooses, but as their internal chemistry predisposes. This stimulus and response activity is explained in biological works dealing with the tension and release of organic functions.
So in the upward scale of life, sex becomes more specialized and refined until, in certain of the higher orders, it
