The Hunting Wasps 



third and sometimes a fourth. Not till 

 then does the Sphex shoot back into the bur- 

 row all the rubbish accumulated outside the 

 door and completely remove all the outward 

 traces of her work. Thus, to each burrow 

 there are usually three cells, rarely two and 

 still more rarely four. Now, as we ascer- 

 tain when dissecting the insect, we can esti- 

 mate the number of eggs laid at about thirty, 

 which brings up to ten the number of bur- 

 rows needed. On the other hand, the ope- 

 rations are hardly begun before September 

 and are finished by the end of the month. 

 The Sphex, therefore, can devote only two 

 or three days at most to each burrow and its 

 provisioning. No one will deny that the act- 

 ive little creature has not a moment to lose, 

 when, in so short a time, she has to excavate 

 her den, to procure a dozen Crickets, to 

 carry them sometimes from a distance in the 

 face of innumerable difficulties, to store them 

 away and finally to stop up the burrow. 

 And besides there are days when the wind 

 makes hunting impossible, rainy days or even 

 merely grey days, which cause all work to be 

 suspended. One can readily imagine from 

 this that the Sphex is unable to give to her 

 buildings the perhaps permanent solidity 

 68 



