PLATE 4 



EXPLANATION OF FIGURES 



13 A tube egg, showing the second polar body in the process of formation. 

 Th^ enveloping follicle cells still retain their continuity. 



14 A tube egg, showing the first polar body at the top, the second polar body 

 in the process of formation at the lower left-hand margin of the egg, and the 

 sperm head at the right, with a portion of the tail. 



312 



