Without regarding as fully justified the opinion that in the female sex sexual abstinence has in all circumstances an unfavorable influence upon the nervous system or even that such abstinence is to be regarded as the principal cause of nervous and hysterical troubles, we must consider it fully proved that in a number of the commonest varieties of nervous disease occurring in neurasthenically predisposed subjects, such as neurasthenia, hysteria and neurosis of anxiety[43], the lack of sexual satisfaction aggravates these troubles, whilst suitably regulated sexual intercourse has an actively beneficial effect. Not, indeed, that it is an infallible means, but none the less the effects are often striking, as I have frequently had occasion to observe, both in young women so affected entering upon marriage for the first time, and also in young widows who have remarried. Especially is this true of women in whom the sexual impulse is exceedingly powerful, and even pathologically increased to the extent of marked sexual hyperæsthesia; likewise also in women whose social circumstances and manner of life induce increased sexual appetite. Be it understood, I refer here to regular and moderate sexual intercourse, and not to sexual excesses, which latter, by inducing nervous exhaustion, may have a distinctly deleterious effect. In many cases, however, we observe in women suffering from sexual neurasthenia, that sexual intercourse, even when practiced at long intervals, gives rise to nervous prostration with deep emotional depression and long-lasting aggravation of the existing nervous disorder. This statement applies with especial force to very hysterical epileptic girls with hereditary predisposition to mental disorder. From the fact that among persons hereditarily predisposed to mental disorder, the unmarried are on the average more often affected with insanity than the married, the inference has been drawn that marriage may be recommended to such persons as a measure likely to counteract their hereditary tendency to insanity. The argument, however, lacks validity, more especially as regards women; among whom, moreover, from the age of sixteen to the age of thirty, insanity is proportionately more prevalent among the married, though above the age of thirty it is more prevalent among the unmarried.