508 THE REPRODUCTIVE SYSTEM 



tissue stroma of the ovary. The indentation which is thus produced 

 is known as the liilum. 



The substance of the ovary is divisible into a central medulla which 

 reaches the surface only at the hilum, and a peripheral cortex which 

 invests all other portions of the medulla and is in turn clothed by a layer 

 of germinal epithelium, a continuation of the peritoneal epithelium, 

 whose cells in this area are peculiar in that they possess a typically 

 cuboidal shape, and are thus sharply distinguished from the flattened 

 mesothelial cells of the surrounding portions of the peritoneum. 



FIG. 449. SECTION OF OVARY OF ADULT CAT, SHOWING FIVE VESICULAR (GRAAFIAN) 

 FOLLICLES, FOUR WITH THE CUMULUS OOPHORUS AND THE ENCLOSED OVUM. 



The antrum folliculi is filled with a granular matter, a coagulum of the liquor 

 folliculi. Note that the ovarian follicles are in the cortical portion, the medulla 

 contains no follicles. Photo. X 7. 



The Medulla. The medulla of the ovary consists of a fibromuscular 

 stroma and large numbers of blood-vessels. Its arteries are characterized 

 by their spirally tortuous course and thick muscular walls; its veins are 

 numerous and large, and their endothelium rests almost directly upon 

 the fibromuscular stroma. This portion of the ovarian stroma consists 

 of fibrous connective tissue in which are elastic fibers and considerable 

 numbers of smooth muscle cells. The connective tissue is richly sup- 

 plied with cellular elements, most of which are ovoid or fusiform in 

 shape. 



The Cortex. The cortex of the ovary likewise contains a vascular 

 stroma and also large numbers of ova which are in all stages of develop- 



