I994 



HUMAN ANATOMY. 







FlG 



Germinal epitheHum 



Primordial ovum 



Ova 



ture medulla of the ovary, is 

 subdivided into the ultimate 

 groups of cells, the primary fol- 

 licles, earlier than the more su- 

 perficial and younger layers, 

 this genetic relation being seen 

 in the fully developed ovary, in 

 which the youngest and least 

 mature follicles always occupy 

 the peripheral zone. The most 

 superficial stratum of the ger- 

 minal ridge remains as the ger- 

 minal epithelium that covers 

 the exterior of the ovary and 

 replaces the usual peritoneal 

 mesothelium plates. 



The details of the trans- 

 formation of the primary folli- 

 cles, consisting of the ovum and 

 the investing single layer of 

 mantel-cells, into the ripening 

 Graafian follicles have been de- 

 scribed (page 1988). Of the 

 thousands of primary follicles 

 within the young ovary (over- 

 estimated by Waldeyer at 

 100,000 in the two ovaries of 

 the new-born child) very few reach maturity.and by advanced life nearly all have 

 M-an-d. This reduction begins during intrauterine life and first affects the fol- 

 licles situated within the deeper parts of the ovary destined to become the medulla, 

 from which the ova are later entirely absent. The remains of these early follicles 

 My account for certain of the minute epithelial bodies occasionally seen in the 

 medulla of voting adults. 



, 



irv from human embryo, 

 kriTmin.il epithelium and 

 r.mi \VulftJ:inbiMly. X 560. 



Nur 'Midi's within the cortex also are continually undergoing destruction. This 



affects especially tin- primarv iollides while tlu-y lit- naked within the stroma, and are unpro- 



tlir iivuin undergoing hyaline degeneration and, along with the mantel- 



cellv tin-lv disappearing within the ovarian stroma. Beginning in the young ovary 



long before puberty, .is u .-|| .is throughout the period of sexual maturity, certain egg-sacs are 



"i'-' 1 - '""' "illy, into C.raatian follicles that develop to a certain 



Stage and are then arrested, after which they enter upon regression, degenerate, and finally may 



Completely disappear. This process, know,, as atresia of the follicles, is probably closely 



related to alterations in th< ir blood-supply (Clark). 



u ' !h I'" '"'">". '>>< formation of new follicles ceases during the first few 



in life being in such lavish excess of all possible 



IM..II is mad.- .tg.mist dearth of reproductive cells. Infrequently 



which two or more ova are present. This condition results from 



than a suvj, primary egg when the follicle was formed and not from 



division of an ovum already i-nclosed. since alter the mantel-cells surround the ovum it is 



