BIOLOGY OF EGGS AND IMPLANTATION 



813 



GRANULOSA 



CELL 





rl 



m- 



'H 



1^: 



JiirMitOCHO 



I M.^% ■"' 



yiLLi 



Fic. 11.7. I'uiiKju ui uiiiLiiuiiiai- luilirli Hum :ai b-Jay-old rat. Tlic zona prlluri.la '././',' 

 is just forming, and is deposited in irregular patches. The Golgi complex, not shown in this 

 micrograph has begun to break up into smaller units. The mitochondria still have a random 

 distribution. (Courtesy of Dr. L. Odor.) 



Woodger, 1920; Kirkman and Severinghaiis, 

 1938 ». 



Also awaiting clarification is the problem 

 as to whether the retraction of the corona 

 radiata cell processes alters the morphology 

 and/or physical characteristics of the zona 

 IK'llucida. The zona apparently is able to 



function as a differential membrane. It has 

 been observed in the rat that accessory sper- 

 matozoa within the perivitelline space re- 

 main intact even until the time of implanta- 

 tion whereas those suspended in the fluids of 

 the oviduct and not incorporated in j^hago- 

 cytic cells undergo complete disintegration 



