THE GENITAL ORGANS OF THE FEMALE. 



985 



On the surface of this fibrous membrane is found a complete layer of 

 cylindrical cells, which was at one time regarded as a dependency of the peritoneal 

 serous membrane ; but it differs widely from it in an anatomical point of view. 

 It is named the germ-epithelium, in order to indicate the share it takes in the 

 production of ova during the early period of their development. 



Proper tissue. — The proper tissue, or stroma, of the ovary is more consistent 

 than that of the testicle ; it is hard, grates on being cut into, and is greyish-red 

 in colour. It is divisible into two layers, distinguishable by their aspect and 

 structure (Fig. 529). 



1. The medullar^/ layer — that nearest the hilus— is slightly red and spongy ; 



SECTION OF THE OVARY. 



1, Cortical vesicles; 2, larger vesicles; 3, vesicles surrounded by the granular membrane; 4, 5. 6, 

 7, 8, follicles in various stages of development; 9, membrana granulosa; 10, ovum; 11, cumulus 

 proligerus; 12, non-ruptured follicle surrounded by a capillary network; 13, follicle with its 

 contents partly escaped ; 14, stroma of the cortical zone ; 15, vessel entering by the hilus of the 

 ovary; 16, stroma of the hilus; 17, external membrane of a corpus lutea ; 18, arteries of a 

 corpus lutea ; 19, its central vein. 



it is formed by an interlacing of the connective fibres, unstriped muscular fibres, 

 and a large number of vessels that radiate from the centre towards the peripheiy. 



2. The cortical layer has the elements of connective tissue for its base ; it is 

 but little vascular, and contains in its substance the Graafian vesicles or follicles 

 {ovisacs), and is consequently often named the ovigenous layer. These ovisacs 

 are in various stages of development ; the smallest are situated beneath the 

 tunica albuginea, and gradually increase as they lie deeper. When fully 

 developed, they are filled with a transparent, citron-coloured fluid ; the 

 ovigenous layer can then no longer contain them, and they protrude more or less 

 from the surface of the ovary. 



A Graafian vesicle, in its perfect state, is composed of an envelope and its 

 contents. The envelope comprises : a fibrous membrane {tunica fibrosa), which 

 is confounded with the stroma of the ovary, and in it we may recognize two 

 layers, the internal of which is rich in vessels ; an epithelium, or membrana 



