ORTHOPTEROIDEA (PANORTHOPTERA) 



213 



convex on one side, straight on the other, and much compressed (Fig. 128), 

 with the micropyles scattered over a quadrant of its upper half. The first 

 maturation division of the egg nucleus occurs before the egg is enclosed 



Fig. 128. — BlaUella. 



Lateral aspect of egg. A, before cleavage. B, after cleavage. 

 {From Wheeler.) 



in its ootheca. After fertilization the cleavage cells migrate to the egg 

 surface, the blastoderm being completed in about 60 hours at 27°C. 

 After reaching the surface some of the cleavage cells turn back into the 



Fig. 129. — Blattella! Section through stomodaeum {stom) of five-day embryo, {am) 

 Amnion, {ect) Ectoderm, {mes) Mesoderm, {ser) Serosa. 



yolk to become vitellophags. Shortly afterward the embryonic rudiment 

 forms in the middle half on the ventral surface (along the V-shaped ridge) 

 of the egg, the blastoderm on the dorsal and lateral surface becoming thin 



