Now, one of the inferences of the gynæcologist is likely to be, that the uterine lesion, of whatever nature it may chance to be, is the cause of the failure in mental and general health; that it is the "_fons et origo_" whence has arisen the long train of nervous symptoms, and, doubtless, in some cases this may be a correct inference; but in a vast majority of cases my impression is that both the existing debility of the nervous system and the uterine lesion are to be regarded as _consequences_, and that neither is a cause of the other, but rather that they both result mainly from a failure in the discharge of those functions which more especially pertain to the sexual system, and a disregard of the laws of health as to physical exercise. But what I desire to specially note in this connection is, that these symptoms or manifestations of nervous derangement are not those of insanity, that they rarely pass over or develop into those of insanity. There is prevalent, both among lay and professional persons, an idea that a large number of females become insane, from the existence of some such uterine conditions, or that these have a large influence in producing insanity. My experience, however, points to an opposite conclusion. It is rare to find any of the uterine lesions referred to existing among insane women; and this is doubtless explicable for physiological reasons. In almost all cases of acute insanity there exists a much larger amount of mental activity than when the brain is in a normal condition. The processes of thought go on during a larger number of hours every day, and the period of sleep, in which there is a demand for a more limited supply of blood in the brain, is correspondingly diminished. Then, again, the character of mental operations is generally of much greater intensity; impressions are more numerous, sensations are more vivid, and thoughts press their way onward through the channels of nerve-cells and fibres of the brain with greater rapidity and constancy. Almost the whole force and energy of the nervous system appear to be centred in the brain, and to supply the wear arising from such increased activity of the brain, the system calls for a larger supply of blood in this organ. It is therefore diverted from other portions, and there results a diminished sensibility and activity especially of the sexual system. In a large majority of these cases also, the monthly discharge ceases to appear, and the sexual functions are in partial abeyance.