Intra-abdominal pressure should be explained in connection with this subject, for it constantly encourages prolapsus of the organs under consideration. By that is meant the pressure which the contents of the abdominal cavity exert on its walls, and this is greatest at its most dependent part, which is the pelvic floor. This pressure is continuous on the organs of the pelvic floor while the woman is standing, and greatest at the point of least resistance, which is the relaxed and enlarged vagina, so that it bulges out at the vaginal orifice. When the patient resumes a recumbent position, this point is greatly relieved from pressure, and the vagina may regain its normal relations, but whenever the woman is in the upright position, the intra-abdominal pressure will again force the weakened pelvic floor and vaginal walls downwards. After a time the prolapse no longer subsides after the pressure is reduced, for the tissues have lost their recuperative power, and the prolapse becomes permanent. When the intra-abdominal pressure is supplemented by the action of the diaphragm and the contraction of the abdominal muscles, as occurs in a long paroxysm of coughing, repeated vomiting, and inordinate and prolonged bearing down at stool, a prolapse may take place quite suddenly, precisely as in a rupture or hernia, and for these reasons some authorities (Drs. Hart and Barbour, of Edinburgh) have described prolapsus of the womb as a _sacro-pubic_ hernia. A permanent distension of the bladder or an accumulation of feces in the rectum facilitates the development of a prolapse of the vagina, because the former pushes the anterior wall of the vagina downwards, while the latter depresses the vaginal wall. A large or subinvoluted uterus is by some considered as a fruitful cause of prolapse; this Professor Schroeder denies, and I am convinced from experience that he is right. A uterus that is simply enlarged is not inclined to prolapse, because the enlarged pregnant uterus never prolapses if the pelvic floor is in a normal condition. But a chronic endometritis or uterine catarrh may in time involve the vagina in a vaginal catarrh and this may induce a prolapse. A chronic vaginal catarrh or leucorrhœa can so relax the vaginal walls that its lower folds protrude from the vaginal orifice. Women who are beyond the change of life and in whom the lost elasticity of the tissues and a general absorption of fatty and connective tissue has destroyed the natural support which retains the vaginal walls, may be annoyed with partial prolapses of the vagina. The most aggravated types of prolapses are found among the working classes, who cannot avail themselves of the comforts and hygiene of the lying-in chamber that are so essential for a complete and permanent recovery.