THE EEPEODUCTIVE ORGANS. 745 



border of the ovary is called the hilum, and it is at this point that the 

 blood-vessels and nerves enter it. Each ovary measures about an inch 

 and a half in length (3.75 cm.), three quarters of an inch in width 

 (1.86 cm.), and nearly half an inch (1.25 cm.) in thickness, and is 

 attached to the uterus by a narrow fibrous cord (the ligament of the 

 ovary), and, more slightly, to the Fallopian tubes, by one of the fimbrias 

 into which the walls of the extremity of the tube expand. 



Structure. A layer of condensed connective tissue, called the tunica 

 albuginea, surrounds the ovary, and this is covered on the outside by epi- 

 thelium (germ-epithelium), the cells of which although continuous with, 



Fig. 443. View of a section of the ovary of the cat. 1, outer covering and free border of 

 the ovary; 1', attached border; 2, the ovarian stroma, presenting a fibrous and vascular struct- 

 ure ; 3, granular substance lying external to the fibrous stroma ; 4, blood-vessels ; 5, ovigerms in 

 their earliest stages occupying a part of the granular layer near the surface; 6, ovigerms which 

 have begun to enlarge and to pass more deeply into the ovary; 7, ovigerms round which the 

 Graafian follicle and tunica granulosa are now formed, and which have passed somewhat deeper 

 into the ovary and are surrounded by the fibrous stroma; 8, more advanced Graafian follicle 

 with the ovum imbedded in the layer of cells constituting the proligerous disc ; 9, the most ad- 

 vanced follicle containing the ovum, etc. ; 9', a follicle from which the ovum has accidentally 

 escaped; 10, corpus luteum. x 6. (Schron.) 



and originally derived from, the squamous epithelium of the peritoneum, 

 are short columnar (A, fig. 444). 



The internal structure of the organ consists of a peculiar soft fibrous 

 tissue a kind of undeveloped connective tissue, with long nuclei 

 closely resembling unstriped muscle (C, fig. 444) or stroma^ abundantly 

 supplied with blood-vessels, and having embedded in it, in various stages 

 of development, numerous minute follicles or vesicles, the Graafian 

 follicles, or sacculi, containing the ova (fig. 444). 



If the ovary be examined at any period between early infancy and 

 advanced age, but especially during that period of life in which the 

 power of conception exists, it will be found to contain a number of 

 these vesicles. Immediately after the tunica albuginea (fig. 444) they 

 are small and numerous, either arranged as a continuous layer, as in the 

 cat or rabbit, or in groups, as in the human ovary. These small follicles 



