AFFECTION OF INSECTS FOR THEIR YOUNG. 357 



velops them as effectually to preserve- them of the re- 

 quired temperature : and having performed this last duty 

 to her progeny she expires. 



The ovipositor of the Capricorn beetles, an infinite 

 host, is a flattened retractile tube, of a hard substance, 

 by means of which it can introduce its eggs under the 

 bark of timber, and so place them where its progeny 

 will find their appropriate food a . The auger used by 

 certain species of QEstrus, to enable them to penetrate 

 the hides of oxen or deer and form a nidus for their eggs, 

 has been before described 11 . But to enumerate all the 

 varieties of these instruments would be endless. 



The purpose which in the insects above mentioned is 

 answered by their anal apparatus, is fulfilled in the nu- 

 merous tribes of weevils by the long slender snout with 

 which their head is provided. It is with this that Bala- 

 ninus Nucum pierces the shell of the nut, and the weevil 

 (Calandra granaria] the skin of the grains of wheat, in 

 which they respectively deposit their eggs, prudently in- 

 troducing one only into each nut or grain, which is suf- 

 ficient, but not more than sufficient, for the nourishment 

 of the grub that will inhabit it. 



II. Hitherto I have adverted to those insects only 

 which perish before their young come into existence, 

 and can therefore evince their affection for them in no 

 other way than by placing the eggs whence they are to 

 spring in secure situations stored with food ; and these 

 include by far the largest portion of the race. A very 

 considerable number, however, extend their cares much 

 further : they not only watch over their eggs after depo- 



a See Kirby in Linn. Trans, v. 254. t. 12. f. 15. b See above, 150. 



