MASONS 75 



how long it would take them to hunt for and 

 destroy ten dozen small caterpillars, that are the 

 exact tint of the leaves upon which they feed. 

 This is the number that one of these Mason Wasps 

 will requisition for the provisioning of the cells in 

 one of these interesting structures. Every such 

 wasp that is wantonly killed means that number 

 of caterpillars allowed to grow and do incalculable 

 damage to the choice plants of our gardens, it 

 may be. Almost certainly, if a wasp is killed in 

 our garden, it was there on a hunting expedition, 

 and it is our garden that will suffer for our ignorant 

 folly. 



It might be supposed that the choice of a par- 

 ticular insect for the nourishment of her grub is a 

 merely arbitrary proceeding on the part of the 

 parent ; but a circumstance narrated by the Peck- 

 hams throws doubt on such a supposition. They 

 had opened a cell of Odynerus conformis, and in 

 doing so had lost all but one of the caterpillars it 

 contained. The grub " hatched on the morning 

 after we had received it, sloughing off the skin 

 of the e^g, but remaining attached to it, and thus 

 doubling the length of the thread by which it 

 hung. The caterpillar was slightly separated from 

 it, and it seemed to have no notion of feeling about 

 for its food, eating nothing for twenty-four hours, 

 but growing and developing nevertheless. We now 

 piled up some caterpillars in contact with it, and 

 it began to eat, but after its own caterpillar and as 

 many as we dared take from [a nest of O.] anormis 



