AFFECTION OF INSECTS FOR THEIR YOUNG. 357 



but different from Reaumur's, not only incloses a living 

 caterpillar along with its egg in the cell, which it care- 

 fully closes, but at the expiration of a few days, when the 

 young grub has appeared and has consumed its provi- 

 sion, re-opens the nest, incloses a second caterpillar, and 

 again shuts the mouth : and this operation it repeats un- 

 til the young one has attained its full growth a . A simi- 

 lar mode, according to Rolander, is followed by Ammo- 

 phila vulgaris as well as by the yellowish wasp of 

 Pennsylvania, described by Bartram in the Philosophical 

 Transact ions b , and by a Sphex? observed by Duhamel c ; 

 both of which, however, instead of caterpillars, supply 

 their larvae with a periodical provision of living flies. 



What a crowd of interesting reflections are these most 

 singular facts calculated to excite ! With what foresight 

 must the parent insect be endowed, thus to be aware at 

 what period her eggs will be hatched into grubs, and how 

 long the provision she has laid up will suflice for their 

 support ! What an extent of judgement, thus in the 

 midst of various other occupations to know the precise 

 day when a repetition of her cares will be required! 

 What an accuracy of memory, to recollect with such 

 precision the entrance to her cell, which the most acute 

 eye could not discover ; and without compass or direc- 

 tion unerringly to fly to it, often from a great distance 

 and after the most intricate and varied wanderings ! If 

 we refer the whole to instinct, and to instinct doubtless it 

 must in the main if not wholly be referred, our admira- 

 tion is not lessened. Instinct, when simple and directed 



■ Bonnet, ix. 398, b liii. 37 l Heaum. vi. 269. 



