The Nerves of the Pelvis: A, abdominal aorta; B. lumbar vertebræ with intervertebral disks; C, the right portion of the sacrum sawn after removal of os innominatum; D, ureter; E, pyriformis muscle cut at its exit from the pelvic cavity; F, the curve of the rectum, corresponding to the anterior surface of the sacrum; H, virginal uterus feebly developed; K, right ovary displaced somewhat upward; L, bladder; M, levator ani muscle, cut in part: N, ischio-cavernosus muscle; O, corpus cavernosum clitoridis, joining on the other side the clitoris, covered with nerve-filaments; P, symphysis pubis (the whole body being inclined forward, it has become horizontal); T, fimbriated end of Fallopian tube; 1, Lumbar nerves, passing out of the intervertebral foramina to form the lumbar plexus; the lower lumbar and the upper sacral nerves joining to form the sacral plexus in front of the pyriformis muscle; 3, gluteal nerves cut; the pudic nerve springing by several roots from the plexus formed by the lower sacral nerves; 5, fine twigs passing from the pudic nerve to the ischio-cavernosus muscle; the main trunk goes under the symphysis, and ends as the dorsal nerve of the clitoris (21); 6, branches of communication which carry sympathetic twigs to the spinal nerves and spinal twigs to the hypogastric plexus of the sympathetic; 7, principal trunk of the sympathetic in front of the lumbar vertebræ; 8, continuation of the sympathetic in front of the sacrum; 9, aortic plexus; 10, hemorrhoidal plexus, following the arteries of the same name; 11, superior hypogastric plexus, or ilio-hypogastric plexus, which receives many spinal and sympathetic branches : 12, inferior hypogastric plexus, communicating with 13, anterior sacral plexus, made up of spinal and sympathetic branches; 14, from the many ganglia placed in this plexus it has a network appearance; 15, inferior rectal twigs, which pass down even to the sphincter, where they form a network covered by the levator ani: 16, raginal plexus: 17, that part of the inferior hypogastric plexus in the shape of a fine network at the upper end of the vagina gives branches to the bladder, the Fallopian tube, and the clitoris; 18, nerve-twigs which run on the side wall of the uterus (giving branches to it) upward to the Fallopian tube and ovary, where they join the nerves following the ovarian artery, which correspond to the spermatic plexus in man; 19, vesical nerves; 20, uterine plexus; 21, dorsal nerve of clitoris, which joins with the cav ernous plexus of the clitoris from the sympathetic to the glans clitoridis (Rydygier).

FIG. 33.

transversus perinæi muscle, and between the posterior third of the side of the vaginal entrance and the erector clitoridis muscle. They lie between the two layers of the deep perineal fascia, or sometimes under (i. e., above in the erect posture) the deep layer.' They are compound racemose glands, secreting a mucous fluid, just like the smaller glands of the vestibule, and are sometimes called glandulae vestibulares majores. Their excretory duct opens with a minute aperture just in front and outside of the hymen, on the inside of the labia majora, or labia minora if these extend so far back. They contribute to the lubrication of the vulva, especially when pressed upon by the surrounding muscles during sexual excitement.

In the erect posture the vulva is hidden between the thighs. When not artificially spread out, the two lateral halves are in contact in the normal adult woman.

Vulvo-vaginal Gland. The labium majus and minus, the sphincter vaginæ muscle. and the bulb have been partly removed on the right side in order to expose the gland: AA', section of labium majus and minus; B, gland; C, excretory duct; C, stylet introduced into the duct; D, glandular end of duct; E, free end of duct; F. section of bulb; G, ascending ramus of ischium (Huguier).

The vulva receives its arteries from the superficial perineal branch of the internal pudic and the external pudic arteries coming from the femoral. The veins accompany the arteries. On account of the free communications between themselves and with those of the pelvis even a small wound of the vulva, especially when during pregnancy they swell, may cause dangerous or even fatal venous hemorrhage. The lymphatics open into the superficial inguinal glands, which are in communication with the deep inguinal glands and external iliac glands. The nerves come from the superficial perineal nerve, which is a branch of the pudic, the inferior pudendal nerve, which is a branch of the small sciatic nerve, and from the pelvic, or inferior hypogastric, plexus of the sympathetic nerve.

Special features of the vessels and nerves of the clitoris and the bulbs of the vestibule have been treated under the descriptions of those organs.

THE VAGINA.

Until within a few years all descriptions and drawings of the vagina gave a very erroneous idea of this organ. It is a slit in the pelvic floor (Fig. 34, h), having a slanting direction from above and

Ambrose L. Ranney found in every case Bartholin's glands lying posterior to triangular ligament ("The Female Perineum," N. Y. Med. Jour., July-August, 1882, vol. xxxvi. p. 45).

behind downward and forward, at an angle of 60° with the horizon, situated between the bladder and the urethra in front and the rectum

Sagittal Section of Pelvis (Waldeyer): a, symphysis pubis; b, bladder; c, small intestine; d, large intestine; e, anus; f, perineal body; g, vulva; h, vagina; i, uterus.

behind, and extending from the vulva below to the uterus above. It has a slight curve with the concavity forward, corresponding to the shape of the male member when in erection-a curve which is much increased during parturition, when the child rounds the symphysis pubis. When distended it has the shape of a truncated cone with the apex at the vulva and the base at the uterus; but when not distended it is folded together in such a way that the slit on a crosssection has somewhat the shape of the letter H, the anterior and posterior wall being in contact in the middle, and each side wall being folded against itself at the ends (Fig. 35, ra). At the lower end it dips into the vulva, forming the hymen, in the same way as at the upper end the uterus dips into the vagina, forming the vaginal portion. At the upper end it forms a cup, adapting itself closely to the vaginal portion of the uterus, as does the cup to the ball of the toy called "bilboquet" or "cup and ball." The upper, broader end is called the roof or fornix, and in its adaptation to the vaginal portion it forms a shallow pouch in front and a much deeper behind, united by side pouches, forming an even transition from one to the other. The lower end, when we remove the hymen (which will be considered later), forms a circular opening, surrounded by the constrictor vaginæ muscle.