All the organs that are liable to the diseases of women, bear certain anatomical relations to the pelvis, so that the phrase, _pelvic diseases of women_, is often employed instead of the phrase, _diseases of women_, and pelvic surgery means also, surgical procedures, that may be employed for the relief or cure of these diseases. In confinement, the pelvis again comes into more or less prominence, for when the diameters of the pelvic canal have not their normal measurements, there is likely to be an obstruction to the passage of the child into the world, so that mechanical means must be employed to overcome the obstacle. A broad pelvis in a woman is always a guarantee that there will be no insurmountable difficulty in the parturient act. PLATE I shows the shape and locality of the bone in the human body, and gives also an approximate idea of the relation of the pelvis to the rest of the body. While the pelvis was referred to above as a basin or cavity, this is only partly true, for it is also a canal or passageway, through which the child is born. The pelvis is divided by a prominent line into the false and true pelvis. The False Pelvis is all that expanded portion of the pelvic cavity which is above the rim or line that forms a circular ridge, which marks the beginning of the bony canal to which the term true pelvis is applied. The True Pelvis constitutes the lower subdivision of the pelvic cavity. The circular ridge, which marks the division, constitutes also the _inlet_ of the true pelvis, which is much smaller than the upper or false pelvis. Its walls are more perfect and their lower circumference is very irregular and forms what is called the _outlet_. Between the _inlet_ and the _outlet_ we have what is called the true pelvic cavity, in which the internal female generative organs are contained. These organs are located in the following order from before backwards: first, behind the pubis there is the bladder, and behind this is the uterus, and thirdly and a little to the left is the rectum. On each side of the womb, but also in the small or true pelvis, are the Fallopian tubes and ovaries. In this order the anatomical relations are easily remembered, and I believe that every woman should make it an object to learn at least as much of her own anatomy as I have laid down; because there is just little enough, so as not to make it tiresome, and quite enough to insure intelligent reading in the subsequent chapters. The points of differences between the male and female pelvis are entirely on the principle of adaptation to natural functions. The female pelvis has a broadness or greater prominence of the hips and a correspondingly greater pelvic cavity, while that of the male is altogether more massive. Its cavity is deeper and narrower, and the muscular eminences and impressions on the surfaces of the bones are much stronger marked.