INSTINCT OF INSECTS. 471 



having placed a nest of the former under a bell glass, he 

 stuffed the interstices between its bottom and the irregu- 

 lar surface on which it rested, with a linen cloth. This 

 cloth, the bees, finding themselves in a situation where 

 no moss was to be had, tore thread from thread, carded 

 it with their feet into a felted mass, and applied it to the 

 same purpose as moss, for which it was nearly as well 

 adapted. Some other humble-bees tore the cover of a 

 book with which he had closed the top of the box that 

 contained them, and made use of the detached morsels 

 in covering their nest a . 



The larva of Cossus ligniperda, which feeds in the 

 interior of trees, previously to fabricating a cocoon and 

 assuming the pupa state, forms for the egress of the future 

 moth a cylindrical orifice, except when it finds a suitable 

 hole ready made. When the moth is about to appear, 

 the chrysalis with its anterior end forces an opening in 

 the cocoon. If the orifice in the tree has been formed 

 by itself, in which case it exactly fits its body, it entirely 

 quits the cocoon, and pushes itself half way out of the 

 hole, where it remains secure from falling until the moth 

 is disclosed. But if the orifice, having been adopted, 

 be larger than it ought to have been, and thus not ca- 

 pable of supporting the pupa in this position, the pro- 

 vident insect pushes itself only half way out of the co- 

 coon, which thus serves for the support which in the 

 former case the wood itself afforded b . 



The variations in the procedures of the larva of a lit- 

 tle moth described by Reaumur, whose habitation has 

 been before noticed c one of those which constantly 



a Linn. Trans, vi. 254. b Lyonet, Traite analomiquc &c, 16. 

 c VOL. I. 455. 



