WASPS, SOCIAL AND SOLITARY 



other genera the egg changes into a larva imperceptibly, 

 there being no sloughing off of the skin. 



Capra, then, first finds a suitable crevice, and builds a 

 partition across the inner end, the earth being scratched 

 up from some dry, bare spot, and moistened in her 

 mouth. Before gathering the ten or twelve small cater- 

 pillars that are to provision the cell, she lays her egg; 

 and although we could not be sure, we thought that in 

 this case as in the others it was suspended. 



Unless the cell is tightly packed at the beginning, 

 capra certainly needs the filament, for her caterpillars 

 were so far from being reduced to a state of decent im- 

 mobility that we had to press wads of cotton into the 

 tubes in which they were kept to prevent them from 

 wriggling out of the way of the larva. None of our 

 larvae, not even the one-day-old ones, were injured by 

 their activity; but had the egg been left to its fate among 

 them it might have perished. 



Later in September we found O. vagus bringing pel- 

 lets from a sharp-edged hole in the ground. Her method 

 was to carry each load on the wing to a distance of ten 

 or twelve inches, where it was dropped without the lively 

 fling with which Ammophila discards her lump of dirt. 

 The red end of a match stuck into the ground two 

 inches away proved very disquieting to the dainty little 

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