212 THE EMBRYOLOGY OF THE HONEY BEE 



suboesophageal body is formed in the premandibular segment. 

 To this the behavior of the head mesoderm of the honey bee cor- 

 responds closely. The only difference of any consequence is in 

 the formation of the aorta. In Chalicodmna, as in Forficula, late in 

 the development the walls of each coelomic sac become apposed, 

 obliterating the lumen. It is not clear however that a tubular 

 lumen is formed, but from the figures given it appears that this 

 is not the case, but that the aorta is simply a lacuna or blood 

 space bounded above by the walls of the antennal coelomic sacs, 

 but opening below into the cavity of the head. 



