A due estimate of the part which a uterine flexion plays in producing the dysmenorrhoea is important, but very difficult. Theoretically, the narrowing of the canal at the point of flexion should account for the symptoms, but experience does not accord with theory. All cases of flexion are not accompanied by dysmenorrhoea, and when so accompanied removal of the deformity does not always cure. Siredey in 52 observations found only 22 cases of dysmenorrhoea. Emmet's carefully-prepared tables show that in nearly 50 per cent. of anteflexions menstruation is painless. The conditions necessary seem to be extreme flexion, producing an acute angle. In less-pronounced cases it is maintained by many that the flexion is an unimportant factor, and that the dysmenorrhoea depends upon secondary conditions produced by it, as endometritis and congestion. The problem is difficult, and each individual case requires careful study. The facts indicate that there is much in the pathology of this form of disease not yet fully understood. Congestive dysmenorrhoea depends upon an advance of the menstrual congestion beyond the physiological limits. In these cases the patient generally suffers for a few days before the period from a sense of fulness, weight, and heat in the back and pelvic region. Pain follows, is more or less severe, and varies somewhat in character, although generally dull and heavy. The hypogastric region usually becomes distended, and is sometimes very tender to the touch over the ovaries, "especially on the left side, without any reason for the difference being known." After a longer or shorter duration of these symptoms the flow appears, and this is often, especially if free, followed by an amelioration of the pain. In many cases, however, there is no remission of the suffering upon the discharge occurring. Not infrequently the general circulation is affected, the face is flushed, the skin hot, and there is more or less fever. The flow may vary widely as to quantity. It is often at first and for a time more profuse than normal. Leucorrhoea frequently precedes and follows it, persisting during the entire interval. During that time also the patient suffers much from backache and bearing down, with difficulty of walking or of remaining on her feet. Upon examination the vagina is found hot and tumefied, and increased arterial action is evident to the touch. The uterus is tender, enlarged, and heavier than usual. In cases associated with or dependent upon chronic inflammation or areolar hyperplasia the increase of size of the uterus during menstruation is marked. The sound may be used to determine the amount of enlargement and also the amount of tenderness. In cases dependent on endometritis touching the interior of the organ causes severe pain. Dyspareunia is frequently a symptom in this class of cases.