L76 



(;koh(;k w. cokxkr 



other words, the activities of the theca interna cells have become 

 so far modified in the process of their differentiation from the 

 primitive 4 mesoblast of the ovarian stroma that they no longer 

 exercise the function of fibril formation. What new activities 

 they may have assumed, whether they may not now share in 

 producing the hypothetical internal secretions of the corpus 

 luteum, are questions for speculation and further research. 



6vc 



>bv. 



Fig. 2G Diagrams of small portions of walls of corpora lutea at different 

 ages, showing increasing density of connective tissue. Dianol red X after 

 Bouin's fluid. X SO. 1, young corpus luteum (ova in tubes); 2, foetuses 115 

 mm. long; 3, seven days after birth of young. 



Having found that the theca lutein cells are not the fibril- 

 producing elements, one is further surprised to find that the corpus 

 luteum of the sow contains very few fibroblasts of the conven- 

 tional type. It is impossible to convince oneself that there are 

 in the organ any cells other than the two types of lutein cells 



