The uterus is the organ of gestation, receiving the fecundated ovum in its cavity, retaining and supporting it during the development of the fetus, and becoming the principal agent in its expulsion at the time of parturition. In the virgin state it is _pear-shaped_, flattened from before backwards, and situated in the cavity of the pelvis, between the bladder and the rectum. It is retained in its position by the round and broad ligaments (Plate III, _ii_ and _kk_) on each side, but _also by virtue of its anteverted position, and by the vagina and perineum_. Its upper end or base (_a_) is directed upwards and forwards; its lower end, or apex, is directed downwards and backwards in the line of the axes of the inlet of the pelvis. It therefore forms an angle with the vagina. The uterus measures about three inches in length, two in breadth at its upper part, and an inch in thickness, and it weighs from an ounce to one and a half ounces in its healthy condition. The fundus or base is the upper broad extremity of the organ (_a_); it is convex, covered by peritoneum, and placed on a line below the level of the brim of the pelvis. The body (_b_) gradually narrows from the fundus to the neck. Its anterior surface is flattened, covered by peritoneum in the upper three-fourths of its extent, and separated from the bladder by some coils of the small intestines; the lower fourth is connected with the bladder. The posterior surface of the body is convex, covered by peritoneum throughout, and separated from the rectum by some convolutions of the intestines. Its lateral margins are concave and give attachment to the Fallopian tubes (_n_), above. The round ligaments (_i_) are attached below and in front of these, while the ligaments of the ovaries (_o_) are attached behind and below these structures. The cervix or neck of the womb (_c_ _d_ _e_) is the lower rounded and constricted portion of the uterus; around its circumference is attached the upper end of the vagina, which extends upwards a greater distance behind than in front. At the vaginal extremity of the uterus is, in the virgin womb, a round, but after childbirth a transverse aperture, the _os uteri_ or mouth of the womb, bounded by two lips, the anterior of which is thick, the posterior narrow and long. THE FALLOPIAN TUBES.