AFFECTION OF INSECTS FOR THEIR YOUNG. 347 



but is exactly proportioned to their size, eleven or twelve 

 being stored when they are small, but only eight or nine 

 when larger. With respect however to the caution of 

 the wasp in selecting full grown grubs and conveying 

 them uninjured to her hole,, a satisfactory explanation 

 may be given. If those that are but partly grown were 

 chosen, they would die in a short time for want of food, 

 and putrefying would destroy the inclosed egg, or the 

 young one which springs from it. But when larvae of 

 any kind have attained their full size, and are about to 

 pass into the pupa state, they can exist for a long period 

 without any further supply. By selecting these, there- 

 fore, and placing them uninjured in the hole, however 

 long the interval before the egg hatches, the disclosed 

 larva is sure of a sufficiency of fresh and wholesome nu- 

 triment. — To prevent the possibility of any injury to its 

 egg from the motions or voracity of this living prey, the 

 wasp is careful to pack the whole so closely, each grub 

 being coiled above the other in a series of rings, and to 

 consolidate the earth so firmly above them, that they 

 have not the slightest power of motion a . — Those which 

 select more powerful caterpillars, or revenge the injuries 

 of their insect brethren by devoting spiders to the de- 

 struction they have so often caused, take care to sting 

 them in such a manner as, without killing them outright, 

 will incapacitate them from doing any injury. 



Zeal and activity in providing for the well-being of 



their future progeny, not inferior to what are exhibited 



by the tribe of Ichneumons, Spheges, and mason-wasps, 



though less cruelly exerted, are also shown by various spe- 



a Reaum. vi. 2'52. 



