THE OVUM 



39 



FIG, 43 FIG. 14 



/ R K 



II RK II RK-;' 



Ei K 



FA K 

 \ 



\ 



K 



FIG. 15 



FIG. 16 



IF ftp 



FIG. 13. Two polar bodies above. Egg nucleus has become vesicular. 

 Sperm radiation has increased in size. 



FIG. 14. Egg and sperm nuclei approach one another. The sperm radia- 

 tion and the centrosomes move apart. 



FIG. 15. Egg and sperm nuclei closely approximated. The centrosomes 

 arrange themselves on opposite sides. 



FIG. 16. The chromosomes of the egg and sperm nuclei form a monaster 

 stage to give rise to two new cells. 



CSpK, central spindle; EiK, egg nucleus; IFSp, first spindle after fertiliza- 

 tion; G, tail of spermatozoon; IRK, first polar body; II RK, second polar 

 body; IRSp, first polar spindle; IIRSp, second polar spindle; SpC, centro- 

 some of spermatozoon; SpK, sperm nucleus; SpSt, sperm radiation. 



