144 PRACTICAL MICROSCOPY. 



THE OYART. 



The ovary consists of a stroma or ground substance of connective 

 and smooth muscular tissue, in which are scattered various sized 

 spherical bodies or Graafian follicles. 



The stroma is divided into three layers or regions, which are not 

 very sharply differentiated. 



The ovary is covered upon its free surface with a single layer of 

 cells which in early life are cylindrical, becoming shortened with ad- 

 vancing age until after the menopause, when only flattened scales can 

 be demonstrated. 



Immediately beneath the epithelium a thin layer of fibrous tissue 

 presents, with a free admixture of smooth muscle cells, and is 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 specially evident. Occasionally may be seen in 

 this region somewhat ovoid nodules in varying degrees of retrograde 

 change the corpora lutea. They present the phenomena resulting 

 from the maturation of the follicle during menstruation. The accom- 

 panying illustration was drawn from a corpus 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. 



PEAOTIOAL DEMONSTRATION. 



The ovary of a young animal is to be preferred. If the organ can- 

 not be obtained from the human subject, the female of almost any 

 domestic animal will provide an excellent demonstration for the his- 

 tological elements. Let the tissue be hardened with strong alcohol, 

 and sections be cut vertically to the free surface and stained with 

 hsema. and eosin. The sections should include at least one-half the 

 the depth of the organ, so as to exhibit all of the regions. 



SECTION OF THE ADULT HUMAN OVARY. (Fig. 98.) 

 OBSERVE: 



CM 



1. The tunica albuginea. (Note that the layer is not of uniform 

 thickness, and is composed largely of smooth muscular tissue, as 



