BaiRSTOW : IcHNEUMONIDiE. 



147 



our hope will be realised. The ichneumon seems to be aware instinc- 

 tively of the exact spot where the larva is located. Smartly pro- 

 menading about its back, it takes in an ichneumon's eye-view of the 

 scene, as if judging whether the opportunity and place are favourable. 

 Is the specimen a well-fattened one, not sickly and likely to die, and 

 as the Insurance Companies would term it — an ordinary risk ? If 

 satisfied on this point, the insect pierces the caterpillar with its ovi- 

 positor, leaving an egg at every stroke. The grub winces, but does 

 not appear to take very great notice of the oppression, unconscious of 

 the death-knell which seals its doom. One, twenty, perhaps a 

 hundred eggs are deposited, our ichneumon has fulfilled a mission, 



" Not the least obeisance made he, 

 Not a minute stopped or stayed he," 



flying off as carelessly as possible, and leaving its future progeny to 



fate. The eggs soon hatch, and young grubs thus formed feed upon 



the food taken in by the caterpillar, or its natural fat, preserving or 



refusing the vital organs until such a length of time has elapsed for 



the perfect development of the grubling. They then burst through 



the sides or skin of their victim, and spin cocoons in which to pass 



their metamorphosis. Occasionally I believe the eggs are left on the 



outside of the larva, but this is a fact I have never personally noticed. 



The ichneumon strikes deep enough so as to prevent any hindrance 



to the caterpillar's development and various skin changes, and as a 



means of security for its young against such changes. Indeed the 



instinct of this genus presents a type of no ordinary quality. Even 



as the males of Saturnia carpini are intuitively apprised of the conduct 



of the females, and refuse any attractive agency after the event, so 



will an ichneumon refuse to deposits eggs in the body of a larva 



already stung. The smallest ichneumons are the most interesting 



and beautiful under the microscope. 



" Contrivance intricate, expressed with ease, 

 Where unassisted sight no beauty sees ; 

 The shapely limb, and lubricated joint, 

 Within the small dimensions of a point." 



Things of beauty they may be, yet to the poor helpless victims — 

 insatiate demons. 



In the same manner as an entomologist is sometimes startled by 

 perceiving in his breeding cage, instead of a fine bombyx, some gaunt 

 and grim-looking ichneumon, so the hymenopterist will discover 

 instead of a fine Metopius, as expected, some peculiar dipterous insect 

 appearing out of the Bombiis chrysalis. This is a drawback which 

 will have to be encountered, and I would recommend the hymenopterist 



