CHANGES IN THE OVARY 



III 



attachment to the broad ligament) as well as numerous blood-vessels. 

 The surface is lined by a layer of columnar epithelial cells. Witliin 

 are a number of vesicles of various sizes, each with an ovum, 

 surrounded liy an epithelium. These are called Graafian follicles. 

 Certain other structures, consisting of very large yellow-coloured 

 cells enclosed by a branching network of connective tissue, are also 

 often found. These are the corpora lutea or discharged follicles to 



Fig. 2:1. — Secticjn through ovary of rabbit, showing follicles and ova in 

 diflerent stages of development. (L. F. Messel.) 



be descriljed more fully later. The stroma contains, further, a 

 varying number of epithelioid interstitial cells. 



In order to gain a proper understanding of the structural and 

 functional relations of the different parts of the ovary, it is necessary 

 to make some study of its de\'elopmental history. 



Pfliiger^ appears to have been the first to regard the ova- and 

 epitbelial cells of the Graafian follicles as originating either in the 

 form of ingrowths simulating tul.)ular glands, or as solid columns of 

 cells from that embryonic layer which Waldeyer afterwards designated 



' Pfliiger, Ueher die Eierstoi:ki' der Siiinjethiere mid dcs Meiixidien^ Leijizig, 

 1867. 



" The niaiunialian ovum was discovered by von Baei' {Ueber Eiitwicke- 

 lungsgesrhichte d^-r Thiere — Beohachtung und Reflexion, vol. i., Konigsberg, 1828). 

 In 1861 Ciegenbaur showed that the vertebrate ovum was a single cell. 



