In dealing with the sexual appetite the fact should be remembered that encouragement of healthy modesty is a duty in both sexes, and pre-eminently so in the male. Too much of what is called "sexual purity" is very often an expression of sexual perversity. While great stress has been laid on the evil effects of association between boys, too little stress has been laid on the danger of the training of boys by women. The sexual history of boys often demonstrates that their initiation into the sexual life was first at the instance of women older than themselves, often servants, but not rarely sexual "purists" or persons whose ostentatious religiosity covered a sexual perversity. In the healthy association of the sexes there is very little danger, but in such morbid association there is great danger, the more that the morbid conceals itself under religiosity and the allied phases of sexual perversion. Great stress has been laid on the dangers of co-education, but the growing opinion is that education limited to one sex is the source of even greater dangers to both boy and girl. It is a matter of common observation among genito-urinary specialists, alienists and gynecologists, that much of the alleged "purity" so ostentatiously displayed by graduates of colleges limited to one sex, is often the offspring of a sexual perversion which, whether congenital or not, has been fostered by the environment of one sex without the modifying, healthy influence of the other. In dealing with these cases the stigmata first likely to attract the physician's attention are in the milder cases those of the jaws, teeth, nose, throat, ear, and eye. Rapid decay of the teeth often leads to the discovery not merely of constitutional degeneracy, but also of the effects of certain strains which aggravated this. Dentists, mouth, throat, ear, and to a lesser degree eye specialists, are hence in a position to detect degeneracy at its outset. If they do not put the cart before the horse, and refer the constitutional symptoms to the local disturbances, they are in a position to be of eminent service to the race.