This is a most thoughtful paper, of the greatest interest, on the question of the prevention of the spread of venereal diseases, and well worth close study. It is only possible here to give some of the author's conclusions and suggestions. A careful examination of evidence (statistics, etc.) shows that prostitution is the cause of the spread of venereal diseases; that clandestine prostitution is answerable for quite two thirds of this; that in three quarters of the cases a woman prostitutes herself before her legal majority; that prostitutes are generally recruited among girls seduced and abandoned; etc. It therefore follows that the great source of venereal diseases arises from the clandestine prostitution of young women; moreover that man is particularly responsible for its spread. The protection of the young woman against seduction is of the first importance, and it is especially in this connection that the prophylaxis of venereal diseases becomes a social question. The error of those in favour of “regulations” is that they have dwelt particularly on the fact that the diseased prostitute is immediately much more dangerous than the diseased man, losing sight of the not less evident fact that the best means of avoiding the evil would have been to protect her against the man who contaminated her.