them, and they contain loops of the small intestine. These are likewise found in the upper part of Douglas's pouch.

About the elevation of the peritoneum during pregnancy, see the description of the broad ligaments and the ureters, pp. 57 and 82.) The para-uterine pouch is lifted up to the pelvic brim; the para

Position of Viscera at the Pelvic Brim (Hasse): v, bladder; u, uterus; t, tube; o, ovary; e, cæcum: r, rectum; lr, round ligament; pv, appendix vermiformis; d, Douglas's pouch; pu, fold covering ureter; I, para-uterine pouch; II, para-vesical, or obturator pouch; ip, infundibulo-pelvic ligament; s. i, small intestine.

vesical pouch is only lifted in its posterior part; and Douglas's pouch is not interfered with.

The parts that have no peritoneal covering are the anterior wall of the bladder, the anterior surface and the sides of the cervix uteri, the whole lower part of the rectum, and the posterior portion of the middle part of the same.

Function. The function of the peritoneum is to allow free, smooth movement between the viscera. It presents a large surface, with great power of absorption.

THE PELVIC CONNECTIVE TISSUE.

The dense connective tissue forming true ligaments or fascia has already been considered, or will be considered in describing the pelvic floor. Here we have only in view the loose connective tissue, which is found everywhere underlying the peritoneum in larger or smaller quantity, and forming one continuous layer, which is a continuation of the corresponding layer of the adjacent parts. In some places it contains fat. Just above the symphysis pubis, behind the linea alba, is found a considerable layer of adipose tissue, the preperitoneal fat, which constitutes an important landmark in the performance of lapa

Coronal Section of Pelvis, showing the three cavities of the pelvis: the peritoneal, the subperitoneal, and the subcutaneous (Luschka).

rotomy. It is continued behind the symphysis as retro-pubic fat (Fig. 89), and lies here in front of the bladder. Between the base of the bladder and the vagina the connective tissue is rather tight. On the posterior surface of the vagina there is a very loose layer. A large mass is found on both sides of the cervix uteri (Fig. 92), forming under the broad ligaments the parametria, which are united by a thinner portion in front and behind. On the body of the uterus there is only very short connective tissue without fat, but during pregnancy it becomes much looser and increases in bulk. The rectum and the vagina are again imbedded in considerable masses of fatty connective

tissue. At the posterior fornix the distance between the vagina and the peritoneal cavity does not exceed one-third of an inch. From the uterus and the parametrium a thin layer extends between the two layers of the peritoneum which form the broad ligaments, and is here mixed with many elastic fibers and unstriped muscle-fibers. From here it is again continued up into the iliac fossæ and the lumbar region, and forward and backward along the pelvic wall.

The chief bulk of the subperitoneal connective tissue forms a funnel-shaped mass around the cervix and downward around the vagina to the insertion of the levator ani muscle (see Figs. 92 and 97).

Function. The function of the connective tissue is to fill out all free spaces between the organs, to furnish a soft padding around organs of very changeable size, and to be the carrier of vessels and

nerves.

THE PELVIC FLOOR.

The pelvic cavity may be divided into three well-marked subdivisions: the pelvi-peritoneal cavity, the subperitoneal space, and the subcutaneous space (Fig. 92).1

Of these we have already described the first and the second. The boundary-line between the second and the third is a muscular diaphragm the levator ani muscle-which is covered above and below with a fascia, and has openings for the passage of the urethra, the vagina, and the rectum.

We shall now consider what remains to be studied under the three headings-the pelvic fascia, the pelvic diaphragm, and the perineal region.

I. The pelvic fascia (Fig. 93) is a continuation of the iliac fascia. It is attached to the iliac part of the ilio-pectineal line and to an oblique line on the posterior surface of the body of the pubic bone, extending from the upper and inner part of the obturator foramen to a point a little below the symphysis. At the upper end of the said foramen it leaves an opening free for the obturator canal. It descends on the inside of the bodies of the ilium and ischium, about halfway down the pelvic wall, where a strong sinewy cord, the so-called tendinous arch, extends from the spine of the ischium to the pubic bone just inside of the obturator canal (Fig. 94). This part of the pelvic fascia covers the obturator internus muscle, and is also called the obturator fascia. It sends a thinner prolongation backward, covering the pyriformis muscle, and called the pyriformis fascia. At the tendinous arch the pelvic fascia is split into two layers, an upper layer called the vesico-rectal fascia, which bends inward over the levator ani muscle, and a lower layer, which continues to follow

1 The distinction was made by Luschka, but his names, cavum peritoneale, cavum subperitoneale, and cavum subcutaneum are bewildering, the two latter "cavities" being filled with solid tissue.

the obturator internus muscle down to the inner edge of the ischioJust pubic branches, and keeps the name of obturator fascia. below the insertion of the levator ani muscle this fascia gives off another investment of this muscle, called the anal fascia. Together with that part of the obturator fascia situated below the tendinous arch it forms the lining of the ischio-rectal fossa.

Fascia of Pelvic Floor (Savage): B, bladder; V, vagina; R, rectum; P, symphysis pubis; S, sacrum; a, fascia covering psoas muscle; b, obturator fascia; c, tendinous arch; d, reflection of fascia on to the rectum, vagina, and bladder; e, posterior portion of fascia covering sacral vessels and nerves; f, iliac fascia covering iliac vessels; g, gluteal vessels; h, sciatic vessels; i, internal pudic vessels; k, obturator vessels.

From its insertion on the pelvic wall the vesico-rectal fascia goes inward and downward, covering the upper surface of the levator ani muscle, to the base of the bladder, the vagina, and the rectum. In front, near the middle line, a thicker, narrow part of this fascia forms the anterior true ligaments of the bladder, or the pubo-vesical ligaments (see p. 80).

Out

Between the two ligaments the fascia is thin and depressed. side of this ligament lies another, thicker band, the lateral true ligament of the bladder, which is attached to the side of the bladder.

From the under surface of the vesico-rectal fascia a prolongation follows down with the vagina, surrounding it with a sheath that lies outside of the venous plexus and forms a strong ring around the vaginal entrance, where it coalesces with the deep perineal fascia.

From the ischial spine goes a band to the side of the rectum, which is called the ligament of the rectum, and prevents too great lateral movement of the intestine. The fascia follows the rectum down as a sheath which gradually disappears near the anus. From the place

The Levator Ani: appearance when the pelvic outlet is looked at squarely. The cut ends projecting inward are those fibres which run into the recto-vaginal septum (Dickinson).

where it strikes the rectum it is continued over on the pyriformis muscle as the pyriformis fascia.

In some parts a double layer of fascia, with intervening loose connective tissue, serves to allow a sliding movement of one part on the other. Thus the fascia forms a pouch between the base of the bladder and the neck of the womb, extending an inch lower down than the corresponding vesico-uterine pouch of the peritoneum. Between the vagina and the rectum a similar pouch is found which descends nearly to the vaginal entrance.

In its totality the pelvic fascia forms a very irregular fibrous layer under the peritoneal cavity and the underlying loose connective tissue, the function of which is to strengthen the pelvic floor and give support to the organs found in it, especially the bladder, the vagina, and the rectum.