CLEAVAGE IN THE EGG OF CEEEBRATULUS. 



Fig. I. (Cerebratulus lacteus) 



1-7, early cleavage stages of seven eggs operated on at different periods 

 between the formation of the first polocyte and the first cleavage. 1-4, four 

 eggs cut at a stage with only the first polocyte ; 5-7, three eggs cut at a stage 

 with two polocytes. 



