there is formed a groove on its lower surface which extends to the cloacal opening, and is called the genital furrow (Fig. 27).

So far, the organs are identical in both sexes, and they cannot be

A.

pc

FIG. 27.

B.

C.

D.

рс

ls

Development of the External Sexual Organs in the Male and the Female from the indifferent type: A, the external sexual organs in an embryo of about nine weeks, in which external sexual distinction is not yet established, and the cloaca still exists; B, the same in an embryo somewhat more advanced, and in which, without marked sexual distinction, the anus is now separated from the urogenital aperture; C, the same in an embryo of about ten weeks, showing the female type; D, the same in a male embryo somewhat more advanced; pc, common blastema of penis and clitoris or genital tubercle (to the right of these letters in Fig. A is seen the umbilical cord); p, penis; c, clitoris; cl, cloacal opening; ug, urogenital opening; a, anus; ls, cutaneous elevation which becomes the labia or the scrotum, genital folds; 1, labium; s, scrotum; co, caudal or coccygeal elevation (Ecker).

distinguished before the tenth week. The genital tubercle becomes the clitoris, the genital folds form the labia majora, the edges of the genital furrow are developed into the labia minora, a fold of which later surrounds the clitoris, forming its prepuce.

In the tenth week the separation between the rectum and the urogenital sinus is consummated. The genital folds grow together at their posterior end, forming a perineum, which unites with the partition between the urogenital sinus and the rectum. While at first the two canals are in close contact, in the fourth month there is a well-formed perineal body between them.

In the male the genital tubercle forms the penis; the edges of the genital furrow grow together, forming the urethra; and the genital folds form the scrotum and perineum. The line of coalescence is elevated above the surroundings, forming the raphe, which extends from the anus to the meatus urinarius.

In the open condition, which continues until the eleventh or twelfth week, the external genital parts are alike in both sexes, and resemble very much the advanced female organs.

PART II.

ANATOMY.'

Division. The genitals are divided into two groups: the external genitals, which are organs of copulation; and the internal, which are organs of reproduction. To the external genitals belong the mons Veneris, the vulva, and the vagina; to the internal, the uterus, the Fallopian tubes, and the ovaries.

THE MONS VENERIS.

The mons Veneris (Venus' mount) is the lowest part of the anterior abdominal wall, and the only part of the genitals that is visible when the woman stands on her feet. It has somewhat the shape of a trapezoid, and is limited above by a transverse sulcus that separates it from the hypogastric region, on the sides by the inguinal folds, and below it is continuous with the labia majora. It lies in front of the pubic bones and the lower end of the abdominal muscles. It has a convex surface, and falls gently off toward the surrounding parts. It consists of skin, adipose tissue, with many interwoven fibrous and elastic bands, and part of the common superficial fascia. It is rich in nervous fibrils. The skin is coarse, has many sebaceous glands, and is covered by a growth of coarse hair, which is limited by a straight or convex upper line (Fig. 28), and does not extend up to the umbilicus, as in man. It is in most women curly, and darker than the hair of the head. This growth appears about puberty.

Function.-During copulation these hairs come in contact with the corresponding growth of the other sex, and by the irritation thus

Those who wish further information than that warranted by the limits of this work are referred to the excellent articles by Henry C. Coe in the System of Gynecology, and Ambrose L. Ranney, Am. Jour. Obstetrics, March, April, May, June, 1883.

My own special investigations on anatomical questions are found incorporated in the following papers: "Gastro-elytrotomy," N. Y. Med. Jour., Oct. and Nov., 1878; "The Obstetric Treatment of the Perineum," Am. Jour. Obst., April, 1880; “Rest after Delivery," ibid., Oct., 1880; "Laceration of the Cervix Uteri," Archives of Medicine, Oct., 1881; "Additional Remarks on Gastro-elytrotomy, Am. Jour. Obst., Jan., 1883; "Gartner's Canals," N. Y. Med. Jour., March 31, 1883; and "The Improved Cæsarean Section," Am. Jour. Med. Sciences, May, 1888.

caused in the nerves at their root give a pleasurable sensation. The vessels and nerves come from the same sources as those of the vulva (see below).

THE VULVA.

The vulva (Fig. 28) forms and surrounds the entrance to the genital canal.

The following organs compose it: The labia majora, with the four

FIG. 28.

chette; the labia. minora, with the clitoris; the vestibule, with the bulbs; the fossa navicularis; and the vulvovaginal glands.

The labia majora (larger lips, Fig. 28, 1) are two prominent ridges, one on either side of the median line. A transverse incision shows a triangular cut surface. They are situated in front of the descending ramus of the pubes and the ascending ramus of the ischium. The outer surface is convex, of darker color than the rest of the skin, covered with a continuation of the hair on the mons Veneris, and has numerous and large sebaceous and sudoriferous glands. The inner surface is rose-colored, and forms a transition from skin to mucous membrane, having the same glands as the outer surface, and even a few downy hairs. The place where they unite anteriorly is called the anterior commissure, and the place where they unite behind is called the posterior commissure. Here the tissue becomes very thin by the disappearance of the fat which forms a great part of the labia majora. Thus a thin fold is formed called the fourchette. Exceptionally, the fourchette is a continuation of the labia minora. Its lower surface consists of skin which has a dark color, similar to that of the external surface of the labia, while its upper surface is pink, and looks like mucous membrane. In the adult nulliparous woman the lower edges of the labia majora are in contact, cover all the other parts of the vulva, and form a line running in an antero-posterior direction and called rima pudendi. In the new-born child, in whom the labia majora are incompletely developed, the labia

Virginal Vulva: 1, labia majora; 2, fourchette; 3, labia minora; 4, glans clitoridis; 5, meatus urinarius; 6, vestibule; 7, entrance to the vagina; 8, hymen; 9, orifice of Bartholin's gland; 10, anterior commissure of Tabia majora; 11, anus; 12, blind recess; 13, fossa navicularis; 14, body of clitoris (modified from Tarnier).

Hottentot Apron, natural size (Billroth, Fauenkrankheiten, vol. iii. p. 324). Left figure: Adult woman standing upright, the apron hanging between the thighs. Right figure: Adult woman lying on her back, the apron spread out to the sides.