OVARIES. 



239 



cubical epithelium (germinal epithelium), which is a modifica- 

 tion of the peritoneal covering. 



The stroma of the cortex consists of fibrillar connective tissue, 

 which in young individuals is rich in cells whose nuclei have a 

 characteristic appearance. They are long and oval, with a dis- 

 tinct nuclear membrane and a well-marked chromatin network. 

 They are larger than the ordinary connective- tissue nuclei, and 

 resemble more in outline those of smooth muscle (Fig. 183). 



FIG. 183. 



Germinal epithelium 



Nucleus of connective-tissue 

 cell of the stroma 



Blood-vessel 

 Follicular epithelium 

 Primitive ovum 



Primordial ovum 

 Germ hial epithelium 



Nucleus of connective-tissue 

 cell of stroma 



From a section of the ovary of a human embryo in the third month. X 540. 



The structure of the glandular part of the organ and the 

 individual egg follicles can best be understood by a study of 

 the development of the ovary. The egg follicle arises from the 

 germinal epithelium. The first part of the development occurs 

 in embryonic life, while the ripening of the egg does not take 

 place until puberty. The cells of the germinal epithelium 

 increase by division, and some of them develop into large cells 

 rich in protoplasm, with large nuclei and nucleoli. These are 

 called the primordial ova (Fig. 183, A). The germinal epi- 

 thelium grows together with the primordial ova into the under- 

 lying stroma (Fig. 183, B], and gives rise to the column-like 



