“3. The family of the homosexual often contains a larger number of nervous persons and such as deviate from the normal sexual type. (_Hirschfeld_, _l.c._, _p._ 338). _Hirschfeld_ also emphasizes the labile character of the nervous system among homosexuals pointing to the large number of abnormal sexual types in the family of the homosexual. That undoubtedly is a correct observation. It may be explained in two ways: (1) as the result of heredity; (2) as a consequence of a common environment. The extent to which these two factors are at work in particular instances may be ascertained only on the basis of specific inquiries. I can state from my own professional experience that the parents of homosexuals always show abnormal character traits. With remarkable frequency male homosexuals have mothers who are melancholic, or subject to depressions or who are advanced hystericals. All gradations are found, from the emotional, domineering type of woman to the solitary, quiet, submissive woman who becomes a prey to melancholia and eventually must be interned in some institution. Urlinds show just as frequently a pathologic father, a home tyrant, a drinker, morphine fiend, dissolute fellow, ‘lady killer,’ epileptic or hysterical. We will determine later to what extent such parents influence psychically their offspring and the attitude of the children towards them. Careful investigation of life histories will make the subject plain. How do the various writers explain the rise of homosexuality? We have mentioned already that _Hirschfeld_ and all investigators deriving their inspiration from him hold to the theory that homosexuality is inborn. According to them, therefore, it is part of inexorable fate, like the law of the planets.... But _Bloch_ finds the condition baffling in spite of all the explanations furnished by _Hirschfeld_ and reverting to the latter’s chemical theory (_andrin_ and _gynecin_) he concludes: “(1) The so-called ‘undifferentiated’ stage of the sexual instinct (_Max Dessoir_) is often eliminated when the sexual instinct becomes directed towards a definite particular sex among heterosexuals or homosexuals before the advent of puberty. Homosexuality shows a definite, clear direction of the sexual instinct towards the same sex long before puberty. “2. A comprehensive theory of homosexuality must also explain the extreme cases, particularly male homosexuality coupled with complete virility. “3. Sexual parts and genital glands cannot determine homosexuality in those possessing typical normal male genitalia and testicles; neither can the brain itself be the determining factor in genuine homosexuality, because homosexuality cannot be rooted out by the strongest conscious and unconscious heterosexual influences brought to bear upon thought and phantasy,—the condition developing in spite of such influences.