STEUCTURE OF THE OVARY. 473 



The deeper substance of the ovary or stroma is chiefly composed of a 

 fine fibro-uuclear tissue, in which the nuclei are remarkably abundant 

 and distinct. It is als-o mixed with some elastic tissue, and is per- 

 meated by blood-vessels, which are large towards the hilus where they 

 enter, and become gradually smaller towards the surface. Along these 

 blood-vessels in the deeper part of the ovary bands of muscular fibres 

 run, having apparently entered from the broad ligament ; but they do 

 not extend into the more superficial parts of the ovarian stroma. 



There is a general disi)osition of radiation of the bands of stroma 

 froin the hilus towards the surface, determined in the deeper part per- 

 haps by the blood-vessels, but in the superficial part modified by its 

 relation to the Graafian follicles. 



Fi-. 335. 



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Fig. 8:J5. — Portion of the Section of the prepared Cat's Ovary, REPREiENTED in 



THE PKECEDINU FIGURE, MORE HIGHLr MAGNIFIED (frOm SclllOll). 



1, outer covering of the ovary ; 2, fibrous stroma; 3, superficial layer of fibro-nuclear 

 substance ; 3', deeper parts of the same ; 4, blood-vessels ; 5, ovigerms forming a 

 layer near the surface ; (i, one or two of the ovigerms sinking deeper and beginning 

 to enlarge ; 7, one of the ovigerms farther developed, now enclosed by a prolongation of 

 the fibrous stroma, and consisting of a small Graafian follicle, within which is situated 

 the ovum covered by the cells of the discus proligeriis ; 8, a follicle farther advanced ; 

 8', another which is irregularly compressed ; 9, the greater part of the largest follicle, in 

 vihich the following jjarts are seen ; «, cells of the tunica granulosa lining the 

 follicle ; 6, the reflected iinrtion named discus proligerus ; c, vitellus or yelk jiart of the 

 ovum, surrounded by the zona pellucida ; d, germinal vesicle ; e, germinal si)ot. 



Graafian Follicles. — Immediately under the superficial covering 

 of the ovary there is a layer of stroma somewhat different from the 

 deeper parts, and which is so uniformly spread over the organ iis 

 to have received the name of cortical layer. This is particularly 

 obvious in the ovaries of young children, in whom this layer is com- 

 paratively thick, and its appearance is granular from the accumulation 

 in it of an immense number of closely set small vesicles, constituting 

 the early condition of the ovarian or Graafian follicles with their con- 

 tained ova. These more numerous and small vesicles, or follicles, are 



