26 THE EMBRYOLOGY OF THE HONEY BEE 



ably the first cleavage nucleus, is seen at the posterior end of the 

 egg. Later smaller cleavage cells are found in the anterior half. 

 These multiply, spread apart, and finally form the blastoderm, 

 which, as in the honey bee, first appears on the ventral side of 

 the egg, near the anterior end. The large nucleus at the posterior 

 end of the egg meanwhile disappears. 



In concluding it should be said that the account of the cleavage 

 in the egg of the honey bee agrees essentially with those of 

 previous investigators, as far as their observations extend. The 

 accounts of Kowalevski, Biitschli and Grassi are, as regards 

 the cleavage, rather fragmentary and incomplete ; that of Dickel 

 is much more complete and in general correct, although his figures 

 are diagrammatic, and evidently not accurately drawn from 

 actual preparations. Petrunkewitsch (1901) also gives a brief 

 description of cleavage in the drone egg, illustrated by two fig- 

 ures. Among the other Hymenoptera investigated, those whose 

 early development conforms most closely to the bee are Chali- 

 codoma and Polistes. 



