MINERS 35 



the wasp, going backwards, draws its victim into 

 the cell. A cricket so treated will remain alive, 

 though utterly incapable of any movement, for three 

 or four weeks, a much longer period than it takes 

 the wasp-grub to consume it. 



The cricket is laid on its back, and on one of the 

 crickets in each cell a Sphex egg is deposited between 

 the second and third pairs of legs. As soon as the 

 egg is hatched, the young grub attacks the cricket 

 at this point and burrows into its body, eating out 

 all the interior in a week, and leaving nothing but 

 the cricket's skin. The other crickets are similarly 

 disposed of in turn, but, owing to the greater size 

 of the wasp-grub, the pace is accelerated, so that 

 in less than a fortnight from the hatching of the 

 egg all the food is consumed. The grub then con- 

 structs an elaborate cocoon of two separate cases 

 of white or yellowish silk, and within these a case 

 of firmer texture and dark colour with a glossy 

 surface. This is apparently formed of a mixture 

 of fluid silk with the excrementitious matter that 

 has been stored in the intestines all through the 

 feeding period, and its purpose appears to be to 

 protect the grub from damp during the nine months 

 of its incarceration, prior to its assumption of the 

 winged condition. 



The Sand Wasps (Ammophila) have a similar 

 predilection for the vertical shaft and the insect- 

 stocked larders, only this time it is caterpillars that 

 are used. The Ammophilas have the hind body 

 connected to the fore body by a very long and 



