DISSECTION OF THE PELVIS. 



365 



2. The Stroma is composed of fibrous connective tissue with some 

 bundles of non-striped muscular tissue. Some coarser strands start 

 from the bottom of the ovulation fossa, and diverge radially towards the 

 periphery of the organ. In the softer greyish parenchyma between 

 these strands the Graafian follicles are situated, the smaller ones being 

 found towards the centre of the organ, and the larger near the 

 surface. A layer of condensed stroma without any Graafian follicles 

 lies beneath the surface epithelium, and is sometimes termed the 

 tunica albuginea of the ovary. 



Fig. 51. 



Section of Cat's Ovary, magnified (from Schron). 



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. Ovi-sacs forming a layer near the surface; 6. One 

 or two of the ovi-sacs sinking deeper and beginning to enlarge ; 7. One of the ovi-sacs 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 proligerus ; 8. A follicle 

 farther advanced ; 8'. Another which is irregularly compressed ; 9. The greater part of the largest 

 follicle, in which the following parts are seen ; a. Cells of the tunica granulosa lining the follicle ; 

 b. The reflected portion named discus proligerus ; c. Vitellus or yelk part of the ovum, surrounded 

 by the zona pellucida ; d. Germinal vessicle ; e. Germinal spot. _ 



-These are vesicular bodies for 

 A large-sized follicle possesses 



3. The Graafian Follicles, or Ovi-sacs. - 

 the maturation and extrusion of the ova. 

 the following parts : — 



a. The wall of the follicle, composed of an inner delicate tunica 

 2)ropria, and an outer layer — the tunica fibrosa — derived from the 

 surrounding stroma. 



b. The Membrana Granulosa. — This forms an epithelial lining to the 

 wall of the follicle, and consists of several layers of cells. At one point 



