174 



SEVENTEENTH LECTURE. 



The cell body is constituted by a membraneless protoplasma 

 containing fat granules. Each of these ovules is surrounded 

 by a corona of small nucleated cells. The whole is finally 

 enveloped in connective tissue. These are the so-called pri- 

 mordial follicles which, often occurring quite crowded here, 

 present an enormous excess of egg-germs. 



Other primordial follicles (Fig. 5, 2) become larger ; the 

 ovule, which has meanwhile also increased somewhat in size, 

 appears to be surrounded by a thicker hyaline rind. The 

 small investing cells now form a double row (a). 



In the further development, however, both the cell layers 



@; 





■\ 



•"-* 



FlG. 156.— Ovary of the rabbit ; a, germinal epithelium (serosa) : b, cortical or external fibrous 

 layer; c, youngest follicles ; <i, a somewhat more developed older one. 



are separated from each other ; there is thus formed a smaller 

 cavity (Fig. 156, d) filled with a clear albuminous fluid. 



In the growing follicle, this cavity becomes larger and 

 larger. The small cells increase and gradually form a strati- 

 fied epithelium. The ovum lies at one point crowded against 

 the wall, and surrounded and held by a heap of these cells. 

 A developed vascular net-work has, in the meanwhile, also 

 been formed in the follicular walls. 



