In a general way the sexual system in the female exerts a much larger influence on the whole physical and mental economy, than in the male. A very intimate sympathy exists between it and both the stomach and the brain. This becomes especially manifest at the period of puberty, and continues until after the cessation of menstruation. The whole moral nature appears to become changed, or rather it appears to come into existence and activity when the child becomes a woman, and thereafter, for thirty or thirty-five years, the whole person is largely affected one fourth of the time by the functional activity of the pelvic organ. The amount and quality of the blood, and its physiological effect upon the vessels and cells of the brain, must largely depend upon the regularity and perfect discharge of this function; and in the case of married women the whole economy is subject to the large changes which come from conception, pregnancy, child-birth, and lactation. The cessation of menstruation must also, in most cases, be attended by such changes as are of grave import: the calling into a larger activity other organs of the body, especially the liver and the skin for the purpose of eliminating those products of secondary metamorphosis which before had passed from the system by the uterus; the consequent disturbance of the circulation while this adjustment of functions is being made; the increased amount of carbon left in the blood, and its effects upon the brain;--every general practitioner of medicine has abundant occasion to witness how great effects all these experiences produce upon the nervous system; how excited or depressed, how irritable and nervous and changeful the brain becomes from their influence upon it. But in addition to these generally obvious effects, the gynæcologist has occasion to observe other, and which he may regard as no less potent, results of reflex influence on the brain from uterine disturbance of other kinds, which more especially affect the unmarried class, which every year becomes larger among all the older civilizations.