ORIGIN OF THE CORPUS LUTEUM 



157 



losa cells (fig. 14, sp.c). The nature of the inwandering cells is 

 difficult to decide. In places there can be no doubt that they 

 are endothelial in nature and represent the first sprouts from 



ih. ext. 





1 





'<Sp. c. 



Fig. 14 Portion of wall of young corpus luteum (ova found in tubes), show- 

 ing swollen cells of granulosa with inwandering spindle-shaped cells. Mallory's 

 connective-tissue stain, formol fixation. X 810. gr.l.c, granulosa lutein cells; 

 th.int., theca interna; th.ext., theca externa; sp.c, spindle-shaped cells. 



the walls of the thecal capillaries, growing inward to the granu- 

 losa. In the endothelial cells mitoses are not uncommon at this 

 time. It seems quite likely that all the early invading cells are 



