xxxvi.] 



THE OVARY\ 



FIQ. 



. 360. T.S. Ovary. 

 Graaflan follicle ; 



e. Germ epithelium; i. Large 

 2. Middle-sized, and 3. Small 

 (/. Membrana granulosa ; 8. 



otherwise the follicles are cut -into, and the ova are apt to fall out. 

 Thin sections must also be made. 



1. T.S. Ovary (fig. 360). (a.) (L) The body of the ovary, 

 covered on its surface by 

 a single layer of short, 

 columnar, nucleated cells 

 - the germinal epi- 

 thelium. 



(/>.) The substance or 

 stroma, composed of con- 

 nective tissue with numer- 

 ous blood-vessels, and in 

 some places smooth muscu- 

 lar fibres. The connective 

 tissue is denser, and is 

 arranged in several layers, 

 near the surface. 



(c.) Lying in the stroma 

 the Graaflan follicles. 

 Near the surface is a layer 

 of smaller unripe ova <>ya; *. Ovum 



. ... * f Stroma. 



primitive ova (40 /*) 



while the riper and larger follicles are situated deeper in the stroma. 

 Each follicle contains an ovum, but if the section be thin the ovum 

 may drop out and leave only the follicle and its coverings. 



(d.) If the ovary be from an adult animal, a corpus luteum may 

 be found. Its appearance will depend upon whether it has been 

 recently formed or not, and whether the animal was recently preg- 

 nant. If it is of some standing, it is large and more or less spherical 

 in outline, occupying a considerable part of the stroma, with an 

 umbilicus-like centre and radiating lines of connective tissue. Be- 

 tween these are numerous large granular cells. In a recent one 

 there may be a yellow pigment lutein staining the scar. 



(e.) (H) The germinal epithelium, and under it the tunica 

 albuginea, composed of two or more layers of connective-tissue 

 lamellae with fusiform cells crossing each other. It gradually 

 passes into the stroma. 



(/.) The Coverings of the Follicle. Select a well-developed or 

 nearly ripe ovum (.5-5 mm. in diameter). Outside is the theca 

 folliculi, composed of two layers, an outer one fibrous the tunica 

 fibrosa and inside it a layer with blood-vessels the tunica 

 propria. Inside this several layers of cubical cells, constituting 

 the membrana granulosa. From this there projects a mass of 

 cells at one part, forming the cumulus or discus proligerus. The 

 cells are continued as the tunica granulosa around the ovum. 



