1176 



FEMALE GENERATIVE ORGANS. 



the meshes of a stroma or framework, and invested by a serous covering derived 

 from the peritoneum. 



Serous Covering. Though the investing membrane of the ovary is derived 

 from the peritoneum, it differs essentially from that structure, inasmuch as its 

 epithelium consists of a single layer of columnar cells, instead of the flattened 

 endothelial cells of other parts of the membrane ; this has been termed the ger- 

 minal epithelium of Waldeyer, and gives to the surface of the ovary a dull gray 

 aspect instead of the shining smoothness of serous membranes generally. 



Stroma. The stroma is a peculiar soft tissue, abundantly supplied with blood- 

 vessels, consisting for the most part of spindle-shaped cells, with a small amount 

 of ordinary connective tissue. These cells have been regarded by some anatomists 

 as unstriped muscle-cells, which, indeed, they most resemble (His) ; by others as 

 connective-tissue cells (Waldeyer, Henle, and Kolliker). On the surface of the 

 organ this tissue is much condensed, and forms a layer composed of short connec- 

 tive-tissue fibres, with fusiform cells between them. This was formerly regarded 

 as a distinct fibrous covering, and was termed the tunica albuginea, but is nothing 

 more than a condensed layer of the stroma of the ovary. 



Graafian Follicles. Upon making a section of an ovary numerous round trans- 

 parent vesicles of various sizes are to be seen ; they are the Grraafian vesicles or fol- 

 licles, the ovisacs containing the ova. Immediately beneath the superficial covering 

 is a layer of stroma, in which are a large number of minute vesicles of uniform size, 

 about Tft-fr of an inch in diameter. These are the Graafian vesicles in their earliest 

 condition, and the layer where they are found has been termed the cortical layer. 

 They are especially numerous in the ovary of the young child. After puberty 



and during the whole of the child- 

 bearing period large and mature, 

 or almost mature, Graafian vesi- 

 cles are also found in the cortical 

 layer in small numbers, and also 

 "corpora lutea," the remains of 

 vesicles which have burst and are 



Granular zone. 



Peritoneum. 



FIG. 754. Section of the ovary. (After Schron.) 1. 

 Outer covering. 1'. Attached border. 2. Central stroma. 

 3. Peripheral stroma. 4. Blood-vessels. 5. Graafian fol- 

 licles in their earliest stage. 6, 7, 8. More advanced folli- 

 cles. 9. An almost mature follicle. 9'. Follicle from 

 which the ovum has escaped. 10. Corpus luteum. 



Coats of the 

 Stroma of the ovary \ Graafian vesicle, 

 witkbloodrvessels. Membrana 

 granulosa. 



FIG. 755. Section of the Graafian ves- 

 icle. (After Von Baer.) 



undergoing atrophy and absorption. Beneath this superficial stratum other large 

 and more mature Graafian vesicles are found imbedded in the ovarian stroma. 

 These increase in size as they recede from the surface toward a highly vascular 

 stroma in the centre of the organ, termed the medullary substance (zona vasculosa, 

 Waldeyer). This stroma forms the tissue of the hilum by which the ovary is 

 attached, and through which the blood-vessels enter; it does not contain any 

 Graafian vesicles. 



The larger Graafian follicles consist of an external fibro- vascular coat connected 

 with the surrounding stroma of the ovary by a network of blood-vessels ; and an 

 internal coat, named ovicapsule, which is lined by a layer of nucleated cells, called 

 the membrana granulosa. The fluid contained in the interior of the vesicles is 

 transparent and albuminous, and in it is suspended the ovum. In that part of 

 the mature Graafian vesicle which is nearest the surface of the ovary the cells of 

 the membrana granulosa are collected into a mass which projects into the cavity 



