A number of causes are at hand to explain habitual miscarriage, but, in fairness, it must be acknowledged that physicians are not able to interpret all cases. With one class of patients the muscle fibers of the womb are peculiarly irritable, whereas in another its lining proves incapable of firmly anchoring the ovum. Moreover, derangements of organs which do not belong to the reproductive group may be responsible for the habit. It is a curious fact that the accident is most likely to occur when menstruation would be expected were the individual not pregnant. Obviously, extraordinary precaution is advisable at such times, and if the patient would avoid even the slightest risk, she should not leave her bed. The same purpose will not be served by sitting quietly in a chair, nor by reclining on a couch; complete relaxation and composure are secured only when one lies flat on the back, loosely attired in sleeping garments. I have known several persons with a tendency toward miscarriage who overcame it in this way. Recently one of them who had been delivered prematurely on two former occasions, and who was anxious for a successful issue to her third pregnancy, was willing to remain in bed practically the whole period of gestation. She had her reward; a well-developed infant was born at full term, and has continued to thrive. Prolonged rest in bed, some will say, is debilitating. While that may be true to a degree, untoward effects can always be avoided by systematic massage of the extremities. The abdomen should not be subjected to such manipulations, for they will occasionally provoke painful contractions of the uterus and defeat the purpose of staying in bed. Patients who are not disposed to undergo a long period of enforced rest, no matter what profit may be promised, should at least consent to keep in bed during that period of pregnancy at which a previous miscarriage took place. We know that the event is particularly apt to recur at such a time. Specifically, it is important to remain in bed one week before and one week after the date in question. When pregnancies follow one another in rapid succession, the liability to miscarriage is notably increased. A natural interval between births has been provided, an interval which depends upon the mother nursing her child. Ideally, menstruation, and with it the ripening of the ova (egg-cells), does not occur while the breasts are active; but when the infant does not suckle, the ovaries regularly resume their function in a very short time. Since the circumstances attending miscarriage always deprive the mother of the opportunity of nursing, another pregnancy may quickly ensue unless these facts are appreciated.