Boys of a vigorous habit of body are not inclined to play with their genitals; on the contrary, are often markedly disgusted at an attempt of a schoolboy to instruct them in the vice. They are therefore not easily made victims of, and commonly grow up free from, this vice; but they are the most willing participants in prostitutional debauch, in a more natural way. With the irritated and excited condition of the tissues of the genitals at puberty, then passing the first sexual crisis, what an opportunity for local and general injury must necessarily be present! The nutrition, so essential to growth and development, constantly demanded to compensate for the vicarious and premature waste, great neglect in the natural developments of other portions must necessarily be a result, which is most likely general in character. As the boy grows up, during the years from fourteen to twenty, the attention he pays to his virile member, and the frequency of his seminal emissions, would be astonishing to one not acquainted with the possibilities. In the above we have the most common cause of spermatorrhœa. I venture to say that the disease is rare in subjects who never practiced the vice till after maturity or adult age; but it is nearly as rare to find an adult male who has not, at some period of his adolescence, practiced the vice of masturbation. In addition to the vice of boyhood, the debauch of sexual congress in the natural way, indulged in to enormous excess, produces a state of weakness and loss of general health, with actual impairment of the grey matter of brain and spinal cord, which are reflected upon the genitals in the form of involuntary seminal losses. Spermatorrhœa is only a symptom of a disease, and must be studied as a neurosis. This diseased condition is generally wrought by frequently repeated erotic crises and sexual orgasms, for a long period of time, in conjunction with habitual spermal losses, during the period of development. The frequent repetition of sexual orgasm so completely destroys the erotic sensorii, that the long practice of masturbation destroys the venereal orgasm, and an emission is produced without even a pleasurable sensation; and even the glans penis becomes so anæsthetic in venereal sensibility that the mental effort _only_ produces a venereal excitability enough to bring about an erection. In copulation, such persons do not enjoy a venereal thrill, only by fresh novelties and different females. The subsidence of the venereal thrill, and the loss of erotic sensibility and intensity of enjoyment at sexual crisis, or during sexual orgasm, is evidence that structural changes have occurred and that the disease has become located. Not until structural changes are wrought in the nervous system, is it probable that involuntary seminal losses will continue, or should be corrected as a disease.