§ 2 



HISTOGENESIS OF CORPORA LUTEA 



egg -yolk 



85 



phagocytosis 

 by gran cell 



.theca 



gran cell 



resort and 

 Dhagocyt 



blood 

 . , capillary 



, lympne 

 of 



^,\ theca 



^ irnixed 

 '-•olemmo 



V5 

 '•I asm a 

 and 

 volk 



phagocytosis 



Fig. 65. Advanced stage in the formation of a corpus luteum. Granulosa 

 layer in different stages of resorbent action; phagocytosis of the yolk 

 substance through the granulosa cells. Granulosa cells invading substance 



of yolk. 



dissolve the oolemma and prepare the contents of the ovum 

 for resorption. 



Whereas the first function of the granulosa cells is to 

 prepare and secrete a ferment, their subsequent activity 

 proceeds in the opposite direction, i.e., the absorption of 

 partly liquefied, and partly solid substances from the ovum. 

 Absorption by the granulosa cells takes place through resorp- 

 tion of liquefied ovular substances and phagocytosis of solid 

 yolk elements. The cells which have been emptied by 

 extrusion rapidly fill up v^ith yolk particles of different size 



