1955] 
Roth and Willis — Diploptera dytiscoides 
59 
Figure 1. Wet weight, water, and dry matter changes of the eggs of 
Diploptera dytiscoides with increasing age (as indicated by increase in 
size). All determinations were made on oothecae containing 9 to 13 
eggs, but the data are plotted on a per-eggs basis and include the weights 
of the oothecae. Arrow indicates first sign of visible differentiation of 
the embryo. 
Willis, 1955). The gain or loss in water or solids by the 
eggs of various cockroaches during embryogenesis is 
compared in table 1. Only the egg of Diploptera changes 
greatly with a truly tremendous gain in water and solids. 
