Instances in which miscarriage is attributed to the use of some drug are quite common, and we cannot dismiss them without a word of explanation. Such cases generally fall into one of two classes. Often a drug is given credit for efficiency where conception has been erroneously suspected. Shortly after the menstrual date passes, some medicine is resorted to, and the subsequent phenomenon, regarded as the interruption of pregnancy, is really no more than normal menstruation. In another group of cases miscarriage does actually occur, although the medicine employed plays only a minor role in its production. In such instances the irritation which the drug occasions is the last link in a chain of events leading up to the miscarriage, but the main factor lies in some fundamental imperfection in the pregnancy. Physicians recognize a variety of these imperfections, and know that they may be located in the womb, in the embryo, or in the tissues which unite the one with the other. As an intimate knowledge of pathology is often necessary to recognize the underlying, and therefore the actual, cause of the miscarriage, it is not at all surprising that patients frequently err in their interpretations of such accidents, and emphasize unimportant matters. It would lead us too far afield to attempt to discuss every cause of miscarriage. Nevertheless, there are some very important ones, not yet mentioned, which should be understood by the laity, as appreciation of their significance may avert trouble. In some instances, on the other hand, the accident is unavoidable; to know this should afford the patient a large measure of comfort. Irregularities in the position of the womb are often responsible for miscarriage. Such a condition may exist in women who have not borne children, but it is far more likely to occur as a result of childbirth. After delivery, the enlarged womb becomes the seat of intricate changes, the purpose of which is the restoration of the organ to the condition which existed before conception. It dwindles in size, and gradually drops to its accustomed location within the pelvic cavity. Six weeks are usually required for these changes. At the time of birth it is impossible to predict whether the womb will finally resume a satisfactory position. Accordingly, an examination two to four weeks later is essential. In four out of five patients the organ will be found in its proper location, but, even though it is not, suitable measures adopted at once will generally serve to replace and hold it in good position. On the other hand, if the malposition is not recognized until months or years later, simple procedures will prove inefficient, and a surgical operation will become necessary. Were there no other reason for a careful examination at the end of the lying-in period, it would be amply justified by the information which it gives relative to the position of the uterus.