The _canal_ or opening into the _uterus_ through the cervix is small, capable of admitting a probe ¹⁄₈ to ¹⁄₄ of an inch in diameter. The walls are muscular, and in the unimpregnated state about half an inch in thickness. The cavity of the uterus is small and conical, having three openings, two at its upper portion into the oviducts, and one into the vagina. The latter is called the _Os uteri_ or mouth of the womb. The upper broad portion is called the _fundus_. It weighs from one to two ounces. It is difficult to realize how very diminutive this organ is in the virgin state, especially when we consider its power of distension during pregnancy. The external portion of the uterus is covered by the _peritoneum_, a serous membrane which is continuous with the lining of the abdomen and covering of all the viscera. The uterus is held in place by ligaments formed of folds of the peritoneum. The broad ligament enveloping the oviduct and ovaries extends to either side, and is firmly attached to the sides of the pelvis. The round ligaments, formed from obliterated bloodvessels of fetal life and peritoneal covering, pass from the upper portion of the womb to the outside of the pelvic bone and terminate in muscular and cellular tissue beneath the integument. There are also folds of peritoneum between the womb and bladder in the front, and the womb and rectum in the back, that assist in holding it in position. It is besides largely supported by the elasticity of the vagina and muscles of the perineum. So well sustained is the uterus that only serious violations of physical laws can cause deviations of position. THE VAGINA (Plates II and III) is simply the external outlet or passage from the uterus. It is longer in back than in front, being from three to four inches in front and from five to six inches in the posterior portion. It is a cylindrical tube of firm elastic tissue, capable of great distension. The neck of the _uterus_ dips into the upper part of the vagina about three-fourths of an inch. The communication between these organs is the _cervical canal_, which in health is found closed, admitting a probe with difficulty. The _uterus_ and _vagina_ are not one and the same as many suppose, yet communicate with each other. The vagina serves as a passage for the menstrual fluid, for the fetus at birth, and for the reception of the male organ in copulation, and in a state of health assists the perineal muscles in sustaining the uterus. THE MAMMARY GLANDS or breasts (Plate XI) are accessory to the generative system. They secrete milk which supplies the child with nourishment after birth. They are rounded and prominent, keeping their form and position through life, if the surrounding muscles and tissues have not been weakened by pressure of clothing.