THE OVARY 203 



(L.) 



Find the three principal layers : the mucous membrane, with 

 its folds ; the muscular layer, consisting of unstriated muscle, 

 divided into an inner circular and an outer longitudinal band ; 

 and the thin serous covering. 

 (H.) 



The mucous membrane consists of a fibro- elastic basis, covered 

 by a single layer of columnar ciliated epithelial cells, which will 

 be found well preserved at the bottoms of the folds. 



THE OVARY 



The ovary consists of a stroma or ground -substance of connec- 

 tive and smooth muscular tissue, in which are scattered various 

 sized spherical bodies, the Graafian follicles . 



The stroma is divided into three layers or regions, which are 

 not very sharply differentiated. 



The free surface of the ovary is covered with a single layer of 

 low columnar epithelial cells, called the germinal epithelium. 



Immediately beneath . the epithelium is a thin layer of fibrous 

 tissue, termed the tunica albuginea. 



The cortex proper, or second layer, is distinguished by the 

 Graafian follicles, which will be described later. 



The central portion of the organ, the zona vasculosa, is largely 

 occupied by thick-walled blood-vessels, among which the extremely 

 tortuous arteries are especially evident. Occasionally one may see 

 in this region somewhat ovoid nodules in varying degrees of retro- 

 grade change the corpora lutea. They present the phenomena 

 resulting from the maturation of the follicle during menstruation. 

 The accompanying illustration, Fig. 128, was drawn from a cor- 

 pus luteum which had formed in the site of a Graafian follicle, the 

 contents of which had escaped at some menstrual epoch, and been 

 followed by impregnation. 



PRACTICAL DEMONSTRATION 



The ovary of a young animal is to be preferred. If the organ cannot be 

 obtained from the human subject, the female of almost any domestic animal 

 will provide an excellent demonstration for the histological elements. Let the 

 tissue be hardened with strong alcohol, and sections be cuti vertically to the 

 free surface and stained with hsematoxylin and eosin. The sections should 

 include at least one-half the depth of the organ, so as to exhibit all of the 

 regions. 



