Hence at the approach of menstruation it is the duty of parents and teachers to assist the girl with their advice. The regular regimen at the time of menstruation must be, first of all, more rest and little physical exercise. Standing too much, dancing, swimming, horseback riding, cycling, out-door games, must all be forbidden. The girl needs more sleep at that time. She must avoid excitement. She must guard herself against the exposure to draughts, chills or to getting wet feet. Cold baths must be omitted, but she ought to take regularly her warm baths. Especially should the genital organs be frequently washed with warm water. Tight clothing is particularly injurious at that time. _Pollutions._—The boy needs a different lesson at this period. He has to be told that, at the time of maturity, the testicles begin to produce or secrete spermatozoa which fill the seminal vesicles about once or twice a month. Here the sperm is, as a rule, reabsorbed when no external pressure, such as from the filled bladder or rectum, is exerted upon the vesicles. In the daytime the bladder and rectum are regularly emptied, and the pressure from this side is at a minimum. During the secretion of the spermatozoa the nerve apparatus of the genital system is charged with vital energy. When the tension becomes very high, which coincides with the filling of the vesicles with sperma, the nervous tension and the physical pressure are both eager to discharge, respectively, to evacuate. When the bladder and rectum are filled during the night, their pressure upon the seminal vesicles becomes so great that the latter evacuate and thus cause an ejaculation and a change both in blood and nerve-supply. This relief from the physiological congestion and nervous tension gives a feeling of satisfaction and pleasure. The boy is awakened and is conscious of what has happened.[BO] Boys, therefore, must be taught that these pollutions, if they happen only once to three times a month, are entirely normal and have absolutely no pathological significance whatsoever. The appearance of nocturnal emissions is merely a proof that the boy is approaching manhood. Hence there is no necessity for him to resort to prostitution to get rid of the nocturnal losses, or the so-called wet dreams, as many a boy has done, sometimes even upon the advice of his parent or of some medical authority.