84 



THE AMERICAN ARBACIA 



Jelly 



Vitelline 

 membrane 



Cortical 

 layer 



Cortical 

 granules 



Endoplasm 



Pigment 

 granules 



Fig. 9. Diagram of membranes and layers of unfertilized egg of Arbacia 



punctulata. E. B. Harvey and K. Dan. The plasma membrane is not shown; 



it lies just outside the cortical layer, and inside the vitelline membrane; or, 



according to Parpart and Laris (1954), inside the cortical layer. 



Jelly 



Fertilization 

 membrane 



Perivitelline 

 space 



Hyaline 

 layer 



Cortical 

 layer 



Endoplasm 



Pigment 

 granules 



Fig. 10. Diagram of membranes and layers of fertilized egg of Arbacia 

 punctulata. E. B. Harvey and K. Dan. 



