APRIL, 1900. PECKHAM— INSTINCTS AND HABITS OF WASPS. 
93 
dition of the caterpillars is like that which we find in O. capra. 
Fabre, in discussing the theory of natural selection, considers it 
a fact of immense importance that in these species the egg and 
young larva are so placed as not to be imperilled by the wriggling 
of the caterpillars. He thinks that if the egg, so delicate that the 
least pressure would crush it, were placed among the mass of cater- 
pillars, nothing could save it from destruction. Certainly the 
adaptation does seem to be a peculiarly beautiful one, but where 
is the necessity of it in the case of nidulator, whose caterpillars 
never move at all? And is it, after all, so important in the case 
of the other species? The caterpillars of capra were in the same 
threateningly active state that was found in those of reniformis, 
and yet the w^asp-larvae which we dropped in among them, even 
the youngest, which could not have been more than a day old, 
were not in the least harmed by their contortions. The egg stage 
of capra, like that of nidulator, is four days, and the larval stage 
is probably six or seven. 
