ICHNEUMONS OF ALL SIZES. 33 



Even with a group of insect eggs, guard them as we may, 

 we can never be certain that some parasitic occupant has not 

 possessed them before ourselves. Kirby tells us of ichneu- 

 mons so minute as to occupy, between two, one egg of a but- 

 terfly ; and Bonnet speaks of the same confined receptacle as 

 affording board and lodging to several of these tiny inter- 

 lopers. When told that out of sixty eggs of the emperor 

 moth, not one was found exempt from their intrusion, we may 

 imagine the large proportion of caterpillars nipped in the 

 embryo, as well as in their growth, by parasitic enemies. 

 Amongst these, all are subject to attack by similar destroyers 

 of various size proportioned to the bulk of their victims, from 

 the minute grub of the leaf-miner, to the bulky caterpillar of 

 a puss-moth or a sphinx ; and commensurate with this wide 

 extent of damage to the caterpillar crew, is, of course, the 

 benefit to the vegetable world and the human race, through 

 these parasitic agents, which, while emblems of evil, are thus 

 made instruments of good. 



Though the gay and beautiful order Lepidoptera thus holds 

 a dangerous pre-eminence as an object of parasitic attack, it is 

 not alone the butterfly and moth which are often robbed by 

 the same agency of their last estate and brightest inheritance. 



We have seen already how a common ichneumon, with a 

 tail-like ovipositor of prodigious length, is accustomed to 

 assail, in the deep nest-hole of a mason wasp, the infant pro- 

 geny of an insect of its own order, that of Hymenoptera / and 



