UMBILICAL CORD 383 



condition. As seen in Fig. 385 they are areas of imperfectly developed 

 skin, and as shown in this case (Lewis, Art. "Umbilical Cord," Buck's 

 Hdb., 2nd ed.) they present all of its fundamental layers. Frequently 

 these cornified areas are less fully developed. They have been compared 

 with the pointed epithelial elevations which cover the surface of the 

 umbilical cord in ruminants, but the latter do not appear as areas of 

 imperfect skin, and probably are entirely different structures. They may 

 appropriately be called villi, but the human "villi" scarcely rise above 

 the surface. Their significance is unknown. 



VAGINA AND EXTERNAL GENITAL ORGANS. 



The vagina consists of a mucosa, submucosa, muscularis and fibrosa. 

 Its epithelium is thick and stratified, its outer cells being squamous and 

 easily detached. It rests upon the papillae of the tunica propria, and 

 is thrown into coarse folds or ruga. Glands are absent. The tunica 

 propria is a delicate connective tissue with few elastic fibers, containing 

 a variable number ^ of lymphocytes. Occasionally there are solitary 

 nodules, above which numerous lymphocytes wander into the epithelium. 

 The submucosa consists of loose connective tissue with coarse elastic 

 fibers. The muscularis includes an inner circular and a small outer 

 longitudinal layer of smooth muscle. The fibrosa is a firm connective 

 tissue, well supplied with elastic elements. Blood and lymphatic vessels 

 are found in the connective tissue layers, and wide veins form a close 

 network between the muscle bundles. There is a ganglionated plexus of 

 nerves in the fibrosa. 



The mucous membrane of the vestibule differs from that of the vagina 

 in possessing glands. The numerous lesser vestibular glands. 0.5-3 mm. in 

 diameter, produce mucus; they occur chiefly near the clitoris and the 

 outlet of the urethra. The pair of large vestibular glands (Bartholin's) 

 also produce mucus; they correspond with the bulbo-urethral glands in 

 the male and are of similar structure. The hymen consists of fine-fibered, 

 vascular connective tissue covered with mucous membrane. The clitoris 

 is an erectile body; resembling the penis. It includes two small corpora 

 cavernosa. The glans clitoridis contains a thick net of veins. It is not, 

 as in the male, at the tip of a corpus cavernosum urethrae which begins 

 as a median bulb in the perineal region; the bulbus in the female exists 

 as a pair of highly vascular bodies, one on either side of the vestibule. 

 Each is called a bulbus vestibuli. The labia minora contain sebaceous 

 glands, 0.2-2.0 mm. in size, which are not connected with hair follicles; 

 they first become distinct between the third and sixth years. The labia 

 majora have the structure of skin. 



