Inversion may occur spontaneously or as the result of manual interference in the removal of the after birth. The fundus may pass but a short distance into the cavity of the organ, or the uterus may be turned completely inside out. Inversion may also result in an unimpregnated uterus from the presence of fibrous polypi, growing from the inner surface of the fundus. These growths, when complicating pregnancy, favor inversion by disturbing the regular expulsive contractions. =Hæmorrhages.= An effusion of blood into the cavity of the uterus, occurs normally at every period of menstruation; from some morbid condition of the vessels of the uterus, it may at times amount to an hæmorrhage. Attending parturition, it may be due to placenta prævia; or following, to atony or defective contraction of the uterine walls, where we find the uterus maintaining its dilated condition with flabby and soft walls; or to spasm or irregular contraction, to which the term, “hour-glass contraction,” has been applied. The presence of polypoid tumors is frequently attended by hæmorrhages. =Peri- or Retro-uterine Hæmatocele=, is an accumulation of menstrual blood, generally in the utero-rectal _cul-de-sac_. It may arise from rupture of a blood-vessel, from defect in the excretion of the menses, or from a morbidly profuse exhalation of blood from the genital organs. The extravasation may be reabsorbed, or may by perforation be discharged by the rectum or vagina, or may lead to suppuration and the formation of an abscess. =Inflammations.= The traces of _acute catarrhal_ inflammation are but seldom to be discovered. They present the same features as catarrhal inflammations of other mucous membranes, congestion and swelling, with a more or less abundant secretion of muco-pus. In _chronic catarrhal inflammations_, the membrane is found thickened, of a brownish or slate-gray color, with a more or less purulent secretion, often blood-streaked. The walls of the uterus may be atrophied or hypertrophied. _Catarrhal erosions_, and follicular ulcers, the result of the bursting or suppuration of the stopped-up follicles, usually accompany catarrhal inflammations. _Acute Metritis._ Here we find the organ swollen and congested, and its substance of a darker color. The mucous membrane shows symptoms of a catarrh, and the peritoneal covering is also congested. Occasionally extravasations of blood are found in the substance or cavity of the uterus. The inflammation may lead to the formation of abscesses within the uterine walls. In _Chronic Metritis_ the organ is generally much enlarged. The walls are remarkably pale and dry, thick and hard. The mucous membrane almost always presents the appearances described under chronic catarrhal inflammation, while the peritoneal covering frequently shows numerous adhesions to the neighboring organs.