306 WASP STUDIES AFIELD 



prise upon finding that she had placed a plug of mud in the 

 mouth of the cell that she had filled with caterpillars, and 

 another thin layer over the top of the hole flush with the 

 surface of the ground, while the tunnel, which for perma- 

 nent sealing is always completely filled, was empty. Here 

 we see that when danger threatened, and insufficient time 

 was at hand to seal the burrow normally, she did the best 

 thing possible to safeguard the young in the shortest pos- 

 sible time. Since we often find from two to four cells 

 emanating in all directions from the central tunnel, it might 

 be that in this case, since this nest had only one cell, her 

 intentions were to return and construct other branch gal- 

 leries and cells from the bottom of this empty main channel, 

 when she felt that an intruder was not lurking near. Such 

 behavior ought to make man feel like a vain pretender 

 when he presumes to lay an exclusive claim to intelligence. 



The burrow was the regular vertical tunnel with the 

 chamber at the bottom turning to one side, as we have al- 

 ready photographed (see fig. 55). There were seven cater- 

 pillars in the chamber, of the species of Loxo siege, dis- 

 cussed fully elsewhere. They were all actively moving, and 

 could even walk about. 



The egg was hanging by a tiny thread from the wall. It 

 had been deposited at 3 p. m. on September 10, and it 

 hatched at 7 130 a. m. on September 13, thus having a period 

 of incubation of about two and one-half days. The minia- 

 ture larva wriggled out through one end of its shell and fell 

 right down among the squirming caterpillars. Their activ- 

 ity seemed to do it no harm, however, for it thrived for ten 

 days and became large and husky, until one morning it 

 was found dead. Fabre thinks that the egg would be in- 

 jured by the wriggling mass of caterpillars, if it were not 

 hung up out of their reach, but here we think, as with O. 

 dorsalis, the egg might be placed among the caterpillars 



