290 



HISTOLOGY. 



a stratum granulosum or peripheral layer of follicular cells, and the cumu- 

 lus oophorus or heap of such cells containing the immature ovum. The 

 cumulus is connected with one side of the follicle although in certain 



rt f Tunica externa 



Hi 



*" I Tunica interna, 



Stratum granulosum 



Cumulus oophorus. 



Egg cell with zona 

 pellucida, nucleus 

 and nucleolus. 



FIG. 332. SECTION OP A LARGE VESICULAR FOLLICLE OP A CHILD EIGHT YEARS OLD. X 90. 

 The clear space within the follicle contains the liquor folliculi. 



sections (such as a horizontal section near the top of the cumulus in Fig. 

 332) it would appear completely detached. The columnar cells of the 

 cumulus adjacent to the ovum are radially arranged, forming the corona 



radiata. The cavity of the follicle, at first cres- 

 centic, becomes so distended with fluid as to 

 be nearly spherical. The fluid, or liquor follic- 

 uli, is an aqueous transudate from the blood 

 vessels. Certain appearances (Call-Exner 

 bodies) in the stratum granulosum have been 

 ascribed to cells undergoing liquefaction, and 

 also to spaces containing a dense liquor. 

 The structure of the egg cell within the cumu- 

 lus will be considered under oogenesis. 



Ovulation and the corpus luteum. Around 

 the mature vesicular follicle the tunica interna 



becomes very thick and cellular, forming elevations toward the stra- 

 tum granulosum. At this stage the follicle is large, being about 

 12 mm. in diameter, and one surface of it is so close to the ovarial 



FIG. 333. OVARY, CUT ACROSS,. 

 SLIGHTLY REDUCED. 



a., Aperture through which the 

 ovum escaped ; c. a., corpus al- 

 bicans; cl., blood clot in a cor- 

 pus luteum of ovulation; th., 

 theca folliculi; v. f., vesicular 

 follicle. (After Rieffel.) 



