I50 C. M. CHILD. 



Explanation of Plate II. 

 Fig. 1. The entrance of the spermatozoon. 



Figs. 2 and 3. Preparation for first maturation spindle ; male pronucleus near sur- 

 face of egg. 



Figs. 4, 5 and 6. First maturation spindle. 



Fig. 7. Resting stage of oocyte-nucleus before second maturation division. 



Fig. 8. Early stage of second maturation spindle. 



