THE FEMALE ORGANS OF GENERATION 283 



beneath the peritoneum. Each vesicle consists of an 

 external fibrovascular coat, connected with the sur- 

 rounding stroma of the ovary by a network of blood-ves- 

 sels. 



The ovum is an extremely minute, spheric body, meas- 

 uring from -2-5-0- to -rio" inch in diameter. 



FIG. 153. Graafian follicle from a girl seven months old : a, Epithelium 

 (membrana granulosa) detached from fibrous membrane ; b, discus pro- 

 ligerus, situated far away from the surface. It contains the ovum, on which 

 the zona pellucida and the germinal vesicle are visible. The surrounding 

 fibrous membrane is not yet separated into two layers, and there is no dis- 

 tinct line of demarcation between it and the surrounding stroma (X 220 

 times ; natural size, 0.351 mm. longest diameter) (Kolliker). 



Discharge of the Ovum. The Graafian vesicles, after 

 gradually approaching the surface of the ovary, burst; 

 the ovum and fluid contents of the vesicle are liberated 

 and escape on the exterior of the ovary, passing thence 

 into the Fallopian tube, the fimbriated processes of 

 which are thought to grasp the ovary, the aperture of the 

 tube being applied to the part corresponding to the 

 matured and bursting vesicle. 



