A second important character of the normal sexual appetite is the special attraction that appearances of health and strength in woman produce in man. Healthy forms, normal odors, a normal voice, a skin healthy in appearance and to the touch, constitute attractions which charm and excite man, while all that is unhealthy or faded, every pathological odor, produce a repulsive effect and hinders or diminishes sexual desire. Everything connected with the sexual organs, their appearance, touch and odor, tend to excite the sexual appetite, all the more when they are usually covered; it is the same with the breasts. The first sexual sensations are of a quite indeterminate nature; something unconscious and obscure inclines the boy toward the female sex and makes it appear desirable. A boy may thus become enamored of the portrait of a woman with a swelling bosom and alluring eyes and be seized with desire, either at their sight or only on remembrance. This desire is not concentrated especially on the sexual act, as with an adult who is already experienced in these matters; it is more generalized and vague, although sensual. For a long time, these repeated aspirations, impulses and desires, remain unsatisfied. In different individuals the imagination associates the most diverse images with such manifestations of the sexual appetite. The objects of the latter appear in dreams and provoke nocturnal erections. The boy soon remarks a sensory localization of his appetites in his sexual organs, especially in the glans penis, but also in the surrounding parts, and the known or only vaguely defined image of the female sexual organs, which is hardly present at the first appearance of his desires, begin to excite him more and more. In natural or savage man, as well as in animals, the boy then makes attempts at coitus and soon attains his object, for, in the state of nature, man marries as soon as puberty is attained. =Nocturnal Emissions.=--In civilized man such difficulties are opposed to marriage, that he replaces it by prostitution, or by more or less unnatural means, as soon as his sexual appetite becomes strong. In those who abstain, the images produced by sexual excitation, combined with erections, act more strongly during sleep than waking and produce ejaculations of semen called nocturnal emissions or pollutions. These generally occur during erotic dreams, and as the dreams produce the illusion of real perception, in quality as well as in intensity, it is not surprising that they are followed by an orgasm and ejaculation of semen.