In addition to the physical discomfort which is coincident with menstruation, and quite as common, are the evidences of mental and nervous instability. These often show themselves in the form of unwarranted irritability, and in a lack of poise and self-control. Drowsiness and mental sluggishness are not uncommon, and many otherwise cheerful women are almost overwhelmed by depression during menstruation. All of these departures from what we are accustomed to regard as the normal, or average, mental and physical state of women are very baffling, as they may persist after every discoverable defect has been corrected. But aside from all other considerations it is of obstetrical importance for the sufferer to ascertain the cause of her discomfort if possible. For example, a misplacement of the uterus is a frequent cause of dysmenorrhea and, if it remains uncorrected, may make conception impossible; or if conception perchance does take place, the malposition of the uterus may later be the cause of an interrupted pregnancy. Endometritis is another cause of menstrual difficulty and if allowed to persist may be one factor in the causation of abnormalities in the attachment of the placenta. There is evidently an intimate relation between the process of menstruation and the functions of the ductless glands throughout the body; a relation which is far from being understood. For example, the administration of various preparations of ductless glands for maladies which are apparently unrelated to menstruation, results not alone in an improvement of the condition treated, but frequently in much more comfortable menstrual periods, as well. It should be borne in mind, also, that the influence exerted by a woman’s mental, or psychic, state upon her menstrual periods is so apparent that it is being given increasingly serious recognition. It is frequently observed that patients who are under treatment for nervous and mental disorders, who are also sufferers from painful menstruation, grow more comfortable during their periods as their neurosis improves. We have constantly before us examples of painful menstruation being relieved coincidently with an improved mental state among women situated at the two extremes of the social and financial scale. Indolent, self-centred and unoccupied women at one end often become excessively nervous and irritable, and suffer great pain with each period, while the overworked, harassed, poverty-stricken women at the other extreme have similarly trying menstrual experiences. When the self-indulgent sister can be persuaded to engage in some form of physical activity and to interest herself in some work which requires mental effort, and which perhaps makes an emotional appeal as well, she frequently finds that her menstrual difficulties become less troublesome.