OX THE CTEXOPHORF. EGG", 



Fig III (all the figures x 40). 17-20, 16-cell stage of eggs cut hori- 

 zontally at various periods of the first cleavage; 21, 16-cell stage of an egg 

 cut obliquely ; 22, 23, 16-cell stage of eggs cut horizontally at the 2-cell 

 stage; 24, 16-cell stage of an egg cut vertically at the 2-cell stage; 25, 26, 

 14- and 16-cell stages (half-cleavage) of an egg fragment cut vertically at the 

 4-cell stage. 



