t>' 



PROVISION FOR REARING THE YOUNG. 1 25 



deeply into the earth, and it is again continued in 

 this direction for about three inches. At the end of 

 this passage three or four chambers are made, usually 

 three; each of these is meant to receive one eg: 

 The insect interrupts its mining task, not form 

 ing the three chambers consecutively; when the 

 first is completed she provisions it — we shall soon see 

 in what manner — and lays an egg there; then she 

 blocks it up, suppressing all communication between 

 this cell and the gallery; this done she bores a second 

 passage, provisions it, and lays another egg, closes up 

 the orifice, and proceeds to prepare the third. This 

 work is pushed on with great activity, and when 

 completed the Sphex entirely fills up the subter- 

 ranean passage, and completely isolates the hope of 

 the race at a depth sufficient to shelter it well. A 

 last precaution is taken : before leaving, the rubbish 

 in front of the obstructed opening is cleared away, 

 and every trace of the operation disappears. The 

 nest is then definitely abandoned, and another one 

 prepared. 



The chambers in which the larvae are enclosed — 

 hastily made with little care, and with rough un- 

 smoothed walls — are not very'solid, and could not last 

 long without slipping ; but as they only have to last 

 for a single season they possess sufficient resistance for 

 the insect's purpose. The larva also knows very well 

 how to protect itself against the roughness of the 

 walls, and overlays them with a silky secretion pro- 

 duced by its glands. 



Wejiave now to consider the nature of the pro- 

 visions placed by the Sphex near the egg. Each cell 

 must contain four crickets. That is the amount of 

 food necessary for a larva during its evolution, and 



