l8 THE GERM CELLS: MITOSIS. MATURATION AND FERTILIZATION 



FIG. i A. 





Vitelline ;- 

 membrane A 



f 



Zona. . 

 pellucida. 



Nucleu 



? 

 ,g 



FIG. i B. 



..Jfc,' ^rKwr 

 'w? 



FIG. i. A, Human ovum examined fresh in the liquor folliculi (Waldeyer). The zona pellucida is 

 seen as a thick, clear girdle surrounded by the cells of the corona radiata. The egg itself shows a central 

 granular deutoplasmic area and a peripheral clear layer, and encloses the nucleus in which is seen the 

 nucleolus; B, ovum of monkey. X 430. 



