THE EUMENIDAE 343 



In the lower cell, the egg or larva must have been lost in 

 removing the soil, but eight caterpillars were unearthed. 

 All but one responded to stimuli; the exceptional one was 

 discolored. Thirty-six hours later, these caterpillars were 

 beginning to pupate. Hence it appears that the caterpillars 

 are either placed in the cell with so slight a sting or mere 

 crushing of the abdomen that they can survive and pupate, 

 or else they are placed there fully alive. It seems improb- 

 able that the caterpillars would pupate if very roughly 

 handled. The caterpillars used are so small, in comparison 

 with the size of the wasp, that it seems that stinging would 

 be quite unnecessary to keep them from resisting. One of 

 the caterpillars in this cell pupated, and, nine days later, 

 emerged an adult butterfly, which was identified as Chara- 

 coma nilotica Rogen [H. G. Dyar]. This gives proof that, 

 if the prey is stung at all, the sting is so slight that it has 

 little or no effect upon the transforming creature. 



Another nest was opened which differed essentially from 

 the first. This one was closed at the orifice with a mud 

 plug. Below this was an empty chamber, possibly an air- 

 space, for three-quarters of an inch, and beyond this the 

 lower or true chamber, nine-sixteenths inch in length and 

 one-quarter inch in width, containing the prey and the larva, 

 while the empty egg-shell swung upon its thread. The ten 

 caterpillars were in these various conditions : two were dead 

 and discolored, five were absolutely normal pupae, and 

 three were live caterpillars, one of which was feeding upon 

 one of the pupae. 



Still another nest comprised three cells plus the air- 

 chamber; the wasp's channel had two cells, very similar to 

 the first described above, and the third or bottom cell was 

 the chamber of a mining-bee which was broken into and 

 afterward utilized. The three cells contained nine, seven 

 and six caterpillars. The air-chamber was three-fourths 



