Sexual neurasthenia is defined by _Eulenburg_ as a neuropsychosis of chronic course, manifesting itself chiefly in the form of excessive irritability of the sensory and psychosensory neuron-systems, in association with excessive tendency to exhaustion of the motor and psychomotor neuron-systems. This exhaustion occurs especially in relation to the genital system, in which we see exhibited the phenomena of irritable weakness, of increased excitability combined with increased tendency to fatigue of the genital nerve apparatus—such chronic morbid disturbances are, according to this author, comparatively rare in women, that is to say, the developed typical picture of the disease does not occur in women, or occurs very rarely. Among 168 patients suffering from sexual neurasthenia, only six were women. Two of these latter were addicted to masturbation, and in the anatomical sense both were still virgins; the rest were married women, not receiving sufficient sexual gratification in their married life, two of these were probably also addicted to masturbation, two indulged in homosexual practices. Onanism, according to _Eulenburg_, is the cause of sexual neurasthenia in women as well as in men. If, however, among the relatively very large number of women addicted to masturbation, there appears to be such a very small proportion of instances of sexual neurasthenia, this depends on the fact that from the nature of onanism in women the physical and also as a rule the psychical consequences are as a whole apt to be much less severe than those arising from similar practices in men; but it depends also on the circumstances that neuromental abnormalities of other kinds and denoted by other names, such as dyspareunia, vaginismus, sexual hysteria, nymphomania, feminine sadism, and tribadism, are apt to arise in consequence of onanism. As regards onanism, so also may it be in regard to sexual excesses and aberrations in general; they may be on the one hand causes, but on the other symptoms and sequelæ, of sexual neurasthenia. Early-acquired or inherited homosexual tendencies and habits may, as _Eulenburg_ further points out, lead to sexual neurasthenia only, but then very easily, when such individuals have allowed themselves, against their nature but in obedience to conventional points of view and to the advice of the relatives, to be persuaded into marriage. That sexual abstinence alone is competent to induce sexual neurasthenia must be dismissed as a fable. II. THE SEXUAL EPOCH OF THE MENACME. By the term _menacme_ I designate the culmination of the sexual development of woman, during which the processes of reproduction, copulation, conception, pregnancy, parturition, and lactation occur.