According to _Moll’s_ estimate, 25 per cent. of the prostitutes of Berlin practice tribadism. According to the experience of this author, in cases in which tribadists live in concubinage, one of them is always a prostitute; the active and the passive rôle are always played by the same respective members of the alliance; the active member is called “papa” or “uncle,” is usually a prostitute, and, like the man in the married state, possesses great comparative freedom in sexual matters, whilst the passive member, the “mother,” is not allowed to form any sexual relations outside the concubinage. According to _Ricardi_, many frigid prostitutes practice with pleasure clitoris-masturbation, cunnilictio, and, especially, sapphism, preferring these perversions to the normal sexual act. Moreover, among prostitutes and female criminals there is no lack of lovers of martyrization, of flagellation, even to the drawing of blood, of tyrannical treatment, and of the initiation of children into the mysteries of sex. [For a detailed account of Sadism and Masochism, see _von Krafft-Ebing’s_ “Psychopathia Sexualis.” These particular perversions, common in men, are rare in women; hence but passing allusion is made to them in the present work.] _Lombroso_ records on account of its rarity a case of masochism observed by him in a woman thirty-five years of age, who liked being whipped. _Moraglia_ reports a remarkable instance of sexual perversion in a girl of eighteen, who preferred to coitus, masturbation associated with the stimulating influence of the odor of male urine; this peculiar form of irritability was so powerful as to drive the girl to masturbation in public urinals, notwithstanding the risk of arrest, which indeed often occurred. According to _Carlier_, there are four or five brothels in Paris which are not infrequently visited by rich ladies in search of tribadistic enjoyments, and ladies of “high life” assemble there for communal orgies; it is noteworthy that prostitutes surrender themselves for such purposes to these women who are outside their own circle with great reluctance, and only for a very high fee. Speaking generally, however, sexual perversion is rarer and less intense in women than in men. This fact is explained by _Lombroso_ on the ground that the erotic element in women’s nature is less active, and that women are less often affected by epilepsy, the principal source of these anomalies. In cases in which the genital organs are healthy we must, with _Westphal_, conclude, with reference to contrary sexual sensation, that the abnormal sexual feelings have a cortical origin.