continued to dream exclusively of men, for several years; and the obscene visions became more frequent than the idealistic.  Gradually, coarse and uninteresting erotic dreams of women began to haunt his mind in sleep.  A curious particular regarding the new type of vision was that he never dreamed of whole females, only of their sexual parts, seen in a blur; and the seminal emissions which attended the mental pictures left a feeling of fatigue and disgust.  In course of time, his wife and he agreed to live separately so far as sexual relations are concerned.  He then indulged his passion for males, and wholly lost those rudimentary female dreams which had been developed during the period of nuptial cohabitation.”

Not only is it possible for the genuine invert to be trained into heterosexual erotic dreams, but homosexual dreams may occasionally be experienced by persons who are, and always have been, exclusively heterosexual.  I could bring forward much evidence on this point. (Cf.  “Auto-erotism” in vol. i of these Studies.) Both men and women who have always been of pronounced heterosexual tendency, without a trace of inversion, are liable to rare homosexual dreams, not necessarily involving orgasm or even definite sexual excitement, and sometimes accompanied by a feeling of repugnance.  As an example I may present a dream (which had no known origin) of an exclusively heterosexual lady aged 42; she dreamed she was in bed with another woman, unknown to her, and lying on her own stomach, while with her right hand stretched out she was feeling the other’s sexual parts.  She could distinctly perceive the clitoris, vagina, etc.; she felt a sort of disgust with herself for what she was doing, but continued until she awoke; she then found herself lying on her stomach as in the dream and at first thought she must have been touching herself, but realized that this could not have been the case.  (Niceforo, who believes that inversion may develop out of masturbation, considers that dreams of masturbation by association of ideas may take on an inverted character [Le Psicopatie Sessuale, 1897, pp. 35, 69]; this, however, must be rare, and will not account for most of the dreams in question.)

Naecke and Colin Scott, some years ago, independently referred to cases in which normal persons were liable to homosexual dreams, and Fere (Revue de Medecine, Dec., 1898) referred to a man who had a horror of women, but appeared only to manifest homosexuality in his dreams.  Naecke (Archiv fuer Kriminal-Anthropologie, 1907, Heft I, 2) calls dreams which represent a reaction of opposition to the dreamer’s ordinary life “contrast dreams.”  Hirschfeld, who accepts Naecke’s “contrast dreams” in relation to homosexuality, considers that they indicate a latent bisexuality.  We may admit this is so, in the same sense in which a complementary color image called up by another color indicates the possibility of perceiving that color.  In