There are thus many reasons for the existing ignorance about homosexuality in women. No outsider suspects the hidden meaning of an advertisement worded, e. g., “Wanted by a lady, a lady friend and companion.” Yet ninety per cent of such advertisements are inserted in the columns of the newspapers by homosexual women. _Homosexual perversity._—Homosexual practices have various reasons. From the outset we have to differentiate between perversity and perversion. It is of great importance to have a clear conception of what constitutes an anomaly. What is abnormal, says Ellis, does not, of necessity, mean pathological. Genius and criminality are anomalies, but they are not, for that matter, diseases. Virchow says that an anomaly may constitute a disposition to a disease, but it is not always the disease itself. The study of anomalies, i. e., pathology, is not the same as the study of diseases, nosology. In the study of homosexuality we must hence distinguish between perversity and perversion. In perversity the anomaly is not congenital. It develops by degrees at a certain age, sometimes after normal intercourse. It is, furthermore, not permanent or absolute. Affection may return to normal channels at any time. Lastly, perversity is not attended by anything that is irresistible and impulsive, as is the case in perversion. Homosexual feeling, therefore, means the feeling for the same sex, not the sexual acts with it. The mere homosexual act does not constitute a perversion. It may be called a perverted instinct, for it is directed outside of the limits within which it is capable of serving its natural purpose; but so is masturbation, which is never considered a perversion. An untainted boy or girl, seduced at the beginning of puberty by persons of the same sex to homosexual practices, may continue them later on for want of opportunity for normal intercourse with the opposite sex. But neither the boy nor the girl will become sexually inverted, although it cannot be denied that there are exceptions to the rule. It may happen that a boy chooses a girlish-looking boy and seduces him to homosexual practices, or that a girl selects a mannish-looking female for her friend and suffers herself ut constupretur ab ea. This practice may become deeply rooted in them, and the result may be the incapability of finding gratification in concarnatione. Yet such cases are exceptions. Generally, as soon as the extrinsic influences cease, the seduced individuals return to normal sexual functions. _Necessity._—In the majority of cases men and women resort to the homosexual mode of gratification for “faute de mieux.” For that reason homosexuality flourishes chiefly in places where great numbers of males or females are segregated. Among the peasants and shepherds in Switzerland, who live for months segregated in the mountains with no opportunity for natural sex activity, homosexuality is very common.