DEVELOPMENT OF THE FEMALE GENITAL ORGANS. 



287 



I 



r.// 



FIG. ^27. PART OF THE OVARY AT BIRTH. 



(After Waldeyer.) 

 a, Epithelium; b, epithelial cord; c, sexual 



cell ; d.^detached cord ; e, group of follicles ; 



f, a single primary follicle ; g, blood vessel. 



(From McMurrich.) 



than the epoophoron; it has been found in various mammals and detected 

 in the human adult. Except for the longitudinal duct, the Wolffian duct 

 is ordinarily obliterated in the female. Fragments may persist in the 

 musculature of the uterus and these 

 "canals of Gaertner" sometimes open 

 into the vagina. 



The ovary, like the testis, develops 

 from the middle part of the genital 

 ridge. The upper end of the ridge is 

 said to be reduced to the band of 

 tissue (fimbria ovarica) connecting 

 the ovary with the uterine tube (Fig. 

 326); except for its ovarian attach- 

 ment this fimbria resembles the 

 others. The ovary is covered by a 

 layer of columnar peritonaeal cells 

 containing scattered large sexual cells. 

 From this layer, cords including cells 

 of both sorts, extend into the deeper 



tissue of the genital ridge (Fig. 327); toward the epoophoron their ar- 

 rangement has been found to suggest a rete. Instead of forming tubules 

 which empty into the Wolffian body as in the male, the sexual cords of 

 the female produce detached islands of cells. The islands become 

 subdivided into groups usually containing a single 

 sexual cell, and known as primary follicles. Their 

 later history will be considered with the adult 

 ovary. The rete cords become vestigial or dis- 

 appear. 



The urogenital sinus which receives the urethra 

 and vagina becomes a shallow space called the 

 vestibule (Fig. 326). The genital papilla, tipped 

 by its glans, 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. 328 with Fig. 302, page 267.) The labia 

 form a prepuce for the clitoris but do not unite 

 beneath it making 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 correspond with the guber- 



g.f. 



g-g-f-" 



FIG. 328. DIAGRAM OF 

 THE EXTERNAL GENI- 

 TAL ORGANS OF A 

 FEMALE EMBRYO. 



a., Anus; g., glans clitori- 

 dis; g. f., lesser genital 

 folds (labia minora) ; 

 g. g. f., greater genital 

 folds (labia majora) ; 

 u. s., uro-genital sinus 

 (vestibule). 



