Many eminent alienists in various countries are very decidedly of the opinion that there is a special tendency to the association of olfactory hallucinations with sexual manifestations, and, although one or two authorities have expressed doubt on the matter, the available evidence clearly indicates such an association. Hallucinations of smell are comparatively rare as compared to hallucinations of sight and hearing; they are commoner in women than in men and they not infrequently occur at periods of sexual disturbance, at adolescence, in puerperal fever, at the change of life, in women with ovarian troubles, and in old people troubled with sexual desires or remorse for such desires. They have often been noted as specially frequent in cases of excessive masturbation. Krafft-Ebing, who found olfactory hallucinations common in various sexual states, considers that they are directly dependent on sexual excitement (_Allgemeine Zeitschrift für Psychiatrie_, bd. 34, ht. 4, 1877). Conolly Norman believes in a distinct and frequent association between olfactory hallucinations and sexual disturbance (_Journal of Mental Science_, July, 1899, p. 532). Savage is also impressed by the close association between sexual disturbance or changes in the reproductive organs and hallucinations of smell as well as of touch. He has found that persistent hallucinations of smell disappeared when a diseased ovary was removed, although the patient remained insane. He considers that such hallucinations of smell are allied to reversions. (G.H. Savage, "Smell, Hallucinations of," Tuke's _Dictionary of Psychological Medicine_; cf. the same author's manual of _Insanity and Allied Neuroses_.) Matusch, while not finding olfactory hallucinations common at the climacteric, states that when they are present they are connected with uterine trouble and sexual craving. He finds them more common in young women. (Matusch, "Der Einfluss des Climacterium auf Entstchung und Form der Geistesstörung," _Allgemeine Zeitschrift für Psychiatrie_, vol. xlvi, ht. 4). Féré has related a significant case of a young man in whom hallucinations of smell accompanied the sexual orgasm; he subsequently developed epilepsy, to which the hallucination then constituted the aura (_Comptes Rendus de la Société de Biologie_, December, 1896). The prevalence of a sexual element in olfactory hallucinations has been investigated by Bullen, who examined into 95 cases of hallucinations of smell among the patients in several asylums. (In a few cases there were reasons for believing that peripheral conditions existed which would render these hallucinations more strictly illusions.) Of these, 64 were women. Sixteen of the women were climacteric cases, and 3 of them had sexual hallucinations or delusions.