Chap. XXI] THE ORGANS OF GENERATION 



443 



and yellow fibrous tissue, blood-vessels, lymphatics, and nerves, 

 (2) Graafian or vesicular follicles, and (3) a covering of columnar 

 epithelial cells, called germinal epithelium, which is continuous 

 with the peritoneum. 



Graafian (vesicular) follicles. — The Graafian follicles are sacs 

 or vesicles which contain the ova and are embedded in the meshes 

 of the stroma. 



Each follicle consists of : (1) an outer coat of fibrous tissue that 

 is derived from the stroma, and connected with it by a plexus of 



Fig. 205. — Uterus, Fallopian Tubes, and Ovaries — Posterior View. 

 1, ovaries; 2, 2, uterine tubes; 3, 3, fimbriated extremity of the left uterine 

 tube, seen from its concavity ; 4, opening of the left tube ; 5, fimbriated extremity 

 of the right tube, posterior view ; 6, 6, fimbrise which attach the extremity of each 

 tube to the ovary ; 7, 7, ligaments of the ovary ; 8, 8, 9, 9, broad ligaments ; 10, 

 uterus; 11, cervix uteri ; 12, os uteri ; 13, 13, 14, vagina. (Sappey.) 



blood-vessels, and (2) an inner layer of nucleated cells. With 

 the exception of the, smallest vesicles each one is filled with fluid, 

 and suspended in this fluid is an ovum surrounded by a mass of 

 cells, called the discus proligerus. 



At birth the ovaries are said to contain about 36,000 vesicles, 

 each measuring from gro to j^ of an inch in diameter, but only a 

 small number of these ever develop, as the great majority shrink 

 and disappear. At the time of puberty the ovaries enlarge, be- 

 come very vascular, and some of the follicles increase in size. As 

 the follicles increase in size they approach the surface and begin 

 to form small protuberances on the outside of the ovary. When 



