PERSEVERANCE AND ITS REWARD. 333 



' When a cocoon contains eggs of G. bidentata, there is often 

 to be found, at its upper end, a minute aperture, through 

 which the ovipositor of the Chrysis has been thrust ; at other 

 times, this aperture is wanting, simply, I believe, because the 

 larva of 0. spini'pes had not done spinning her cocoon when 

 the Chrysis deposited her eggs within it. There is nearly 

 always a small spot outside on the yellow silken top of the 

 cocoon, as if the Chrysis had attacked it fiirst with her jaws ; 

 and those containing G. bidentata may be selected by this mark 

 from a number of cocoons of the Odynerus. 



'The young larva of G. bidentata seizes that of 0. spinipes 

 with its jaws, pinching up a fold of skin, and contrives to* 

 extract fluid nutriment from it, without, apparently, making 

 any aperture in the skin, until it approaches to mature growth 

 itself. I have very carefully examined larvae of 0. spinipes 

 that were thus half sucked away (I cannot say eaten), and I 

 could find no mark at the spot whence I had just removed a 

 larva of Chrysis. I have several times squeezed the Odynerus 

 larva firmly, without any fliud exxiding : even when squeezed 

 almost to bu]-sting, on only one occasion did a drop of clear 

 fluid exude. Nor is the Chrysis larva particular as to where 

 it seizes the Odynerus, any point that may offer itself to its 

 jaws being seized. 



' When the devourer is nearly full-grown, and the victim is 

 very flaccid, a process that may be called eating takes place, 

 and the spinipes larva almost entirely disappears. The manner 

 in which the larvae of G. neglecta and ignita and of 0. spinipes 

 itself eat the little green grubs is precisely similar. When 

 young, they merely suck the juices of several, and sometimes 

 return to and finish tliese when they are larger, but they may 

 often be found neglected when the larva is full-grown.' 



These insects are wonderfully persevering in their attempts 

 to deposit their eggs. A French naturalist mentions that he 

 saw one of them enter the nest of a solitary bee which builds 

 in the holes of walls, while the bee was absent in search of the 

 pollen on which the young larva was to feed. She happened 

 to return while the Euby-tail was still in the nest, and at once 

 attacked the intruder, which endeavoured to avoid her jaws by 

 rolling into a ball, after the fashion of lier kind. Tlie bee, 

 however, persevered in her attacks, bit otF all the enemy's wings^ 



