120 PRACTICAL HISTOLOGY. 



THE FEMALE GENERATIVE ORGANS. 



THE OVARY. 



PREPARATION, (a) Chromic Acid and Spirit Mixture. Harden the entire ovary of a cat, 

 rabbit, or bitch in the above fluid for seven to ten days, and then transfer it to weak, and 

 afterwards to strong, spirit. Make transverse sections, stain some with logwood, and mount one 

 in dammar, and another in Farrant's solution. 



(b) Muller's Fluid. Harden the entire ovaries of any animal in Miiller's fluid. Change the 

 fluid at the end of the first day, and continue the hardening for three weeks. The specimens 

 must on all occasions be handled very gently, to avoid the removal of the germinal epithelium 

 covering them. Transfer them to weak, and then to strong spirit. Both methods yield ex- 

 cellent results. 



Transverse Section of the Ovary. EXAMINATION (L). Observe the framework, which con- 

 sists of (l) the tissue of the hilum, and (2) the stroma of the parenchyma. The tissue of the 

 hilum consists of loose areolar tissue, with many large blood-vessels. The walls of the arteries 

 are easily made out, because they are very thick. The stroma consists of bundles of clear 

 fusiform nucleated cells, with a small amount of fibrous tissue. It is doubtful whether these 

 fusiform cells are muscular or not. Near the surface of the ovary are one or two layers of 

 these cells, which usually contain no ova. In the stroma small groups of polyhedral cells 

 interstitial cells the rudiments of the Wolffian bodies, like those occurring in the stroma of 

 the testis, may be found. Note the single layer of short columnar epithelial cells or germinal 

 epithelium of Waldeyer covering the surface of the ovary. 



Note the Graafian follicles lying in the stroma, and observe their distribution. They are 

 of various sizes and shapes, and the larger ones, i.e. the more developed, lie in the deeper part 

 of the stroma, whilst the smaller ones form a layer two or three deep in the superficial part of 

 the ovary. {Indicate the distribution of the follicles in PI. XXVIIL, Fig 6.) 



Study a large Graafian Follicle (L). Observe the spindle-cells arranged more or less con- 

 centrically around it to form the tunica fibrosa. Within this a membrana propria, lined with 

 several layers of cells, which constitute the membrana granulosa of the follicle, and placed 

 more or less excentrically is the ovum. The ovum is imbedded in, and rests on, some of the 

 cells of the membrana granulosa, and those cells on which it rests form the cumulus proligerus, 

 and these cells are continued around the ovum, as the tunica granulosa, so as to embrace it. 

 A cavity, which is filled with an albuminous fluid, the liquor folliculi, exists between these two 

 layers of the membrana granulosa. The ovum is a complete cell, and consists externally of a 

 hyaline cell-membrane, the zona pellucida ; within this is the transparent yolk or mtellus. Im- 

 bedded usually in one side of the yolk is the germinal -vesicle (nucleus), with its included 

 germinal spot. {Indicate the ovum and membrana granulosa in PI. XXIX., Fig. i.) 



