THE FEMALE KEPRODUCTIVE OEGANS 



515 



chromatolysis in the ovum and its surrounding follicular cells is followed 

 by growth and organization of the theca folliculi, the connective tissue 

 which is thus formed finally replacing the atretic follicle. 



FIG. 454. A VESICULAR (GRAAFIAN) FOLLICLE OF THE HUMAN OVARY, SOMEWHAT 

 MORE ADVANCED THAN THE PRECEDING. 



The accumulation of liquor folliculi has separated the granular cells into a discus 

 proligerus and a membrana granulosa. The membrana propria is very sharp, and 

 the theca folliculi is almost divisible into an inner cellular and an outer fibrous 

 layer. Hematein and eosin. Photo. X 460. 



After remaining stationary for a long period, often for years, certain 

 of the primitive follicles enter upon a period of rapid growth. This 

 process first affects the ovum and results in the appearance of the deuto- 

 plasm, zona pellucida, and other accessory structures, as already de- 

 scribed. Cell multiplication now occurs in the surrounding epithelial 

 cells, so that, instead of the single row of epithelium which surrounds 

 the ovum of the primitive follicle, the ripening follicle soon acquires 



