FEMALE GENITAL ORGANS 353 



The External Genital Organs. The urogenital sinus, which receives the 

 .urethra and vagina, becomes a shallow space called the vestibule (Fig. 353). 

 The genital papilla, with the glans at its apex, becomes relatively shorter as 

 the female embryo develops. It forms the clitoris, analogous with the 

 penis, and is covered by the lesser genital folds, the 

 labia minora. (Compare Fig. 355 with Fig. 329, A, 

 page 331.) The labia form a prepuce for the clitoris 

 but do not unite beneath it to make a raphe; they 

 remain separate, as parts of the lateral boundaries 

 of the vestibule. The larger genital folds, labia 

 majora, likewise remain separate. They receive the 

 ends of the round ligaments of the uterus which pass 



PIG. 3SS- DIAGRAM OF 



into them over the pubic bones, sometimes accom- * EXTERNAL GBNI- 

 panied by a prolongation oi the peritoneal cavity FEMALE EMBRYO. 



r J a., anus; g., glans clitpn- 



forming a processus vaginalis. In late stages of de- f^j- f. 



velopment the labia majora become large enough to foils f aa 



conceal the clitoris and labia minora, which previously (Vestibule)? 1 1 a * smu * 

 project between them. 



OVARY. 



The ovary is an oval body about an inch and a half long, covered by 

 a modified portion of the peritoneum. Along its hilus it is attached to a 

 mesentery, the mesovarium, which is a subdivision of the broad ligament 

 of the uterus. The epithelium of the mesovarium is continuous with that 

 of the ovary, and its connective tissue joins the mass which forms the 

 ovarian medulla. This tissue, rich in elastic fibers and containing strands 

 of smooth muscle, surrounds the vessels and nerves. The blood vessels 

 are abundant, and they pursue a very tortuous course both in the meso- 

 varium and within the ovary. This is strikingly shown in Clark's in- 

 jections (Johns Hopkins Hosp. Rep., 1900, vol. 9). They are derived 

 in part from branches of the uterine vessels, but are chiefly the terminations 

 of the ovarian artery and vein. Large stems traverse the medulla and 

 form capillary plexuses around the follicles in the cortex. Thin-walled 

 lymphatic vessels arise in the cortex below the rather dense sub-peritoneal 

 layer (or tunica albuginea) and pass out at the hilus. The nerves are 

 chiefly non-medullated sympathetic fibers, derived from the plexus which 

 accompanies the ovarian artery, and distributed to the blood vessels. 

 Ganglion cells have been found near the hilus, and a few medullated fibers 

 occur. It is said that certain fibers end in contact with the cells of the 

 follicles. 



The relation of the cortical stroma to the looser tissue of the medulla 

 is so characteristic that sections of the human ovary containing few ova 

 23 



