342 AFFECTION OF INSECTS FOR THEIR YOUNG. 



subsistence for one of her future progeny. Perhaps, 

 however, she discovers, by a sense the existence of which 

 we perceive, though we have no conception of its nature, 

 that she has been forestalled by some precursor of her 

 own tribe, that has already buried an egg in the cater- 

 pillar she is examining. In this case she leaves it, aware 

 that it would not suffice for the support of two, and pro- 

 ceeds in search of some other yet unoccupied. — The pro- 

 cess is of course varied in the case of those minute spe- 

 cies of which several, sometimes as many as 150, can 

 subsist in a single caterpillar. The little Ichneumon 

 then repeats her operations until she has darted into her 

 victim the requisite number of eggs. 



The larvae hatched from the eggs thus ingeniously de- 

 posited, find a delicious banquet in the body of the ca- 

 terpillar, which is sure eventually to fall a victim to their 

 ravages. So accurately, however, is the supply of food 

 proportioned to the demand, that this event does not 

 take place until the young Ichneumons have attained 

 their full growth ; when the caterpillar either dies, or, 

 retaining just vitality enough to assume the pupa state, 

 then finishes its existence; the pupa disclosing not a 

 moth or a butterfly, but one or more full-grown Ichneu- 

 mons. 



In this strange and apparently cruel operation one 

 circumstance is truly remarkable. The larva of the Ich- 

 neumon, though every day, perhaps for months, it gnaws 

 the inside of the caterpillar, and though at last it has de- 

 voured almost every part of it except the skin and intes- 

 tines, carefully all this time avoids injuring the vital or- 

 gans, as if aware that its own existence depends on that 



