CHANGES IN THE OVARY 



127 



tubules. In support of this view Honor e points out that there are 

 no indications of degeneration or destruction of the follicular 

 epithelial cells of the ripe foUicles during oestrus, and moreover, 

 that these cells are retained in the foUicle at the time of ovula- 

 tion, giving rise subsequently to the luteal cells of the corpus 

 luteum. It would appear possible, however, that the liquor 

 folhcuh is formed partly by the secretory activity, and partly 



Fig. 30. — Young human Graafian follicle. The cavity contains the 

 liquor folliculi. (From Sellheim.) 



by destruction of the folhcle cells, just as, according to one 

 view, milk is derived from both the secretion and the disintegra- 

 tion of the cells of the mammary gland (see p. 560). 



Heape ^ states that during the growth of the ovum nour- 

 ishment is supphed to it by the aid of the discus proUgerus, 

 for fine protoplasmic processes may be seen passing from the 

 cells of this layer and projecting into radiating canals in the 

 zona which encloses the ovum, being in contact with the vitelhne 

 membrane. 



' Heape, " The Development of the Mole," Quar. Jour. Micr. Science, 

 vol. xxvi., 1886. 



