CH. XVI.] 



THE CATERPILLAR. 



281 



light, the exact situation of the insect may also be 

 discovered. The narrowest part of the gallery is 

 that through which it has been entered ; the insect 

 as it proceeds grows in size ; it requires more food 

 as well as more space : hence its mine becomes 

 gradually wider ; the head of the creature will there- 

 fore be found towards the widest part, and the tail 

 towards the narrowest end of the streak. The in- 

 struments which these insects use in mining are their 



The commencement of the gallery is under the stalk of the leaf; the 

 gallery is seen gradually to widen, and at the farthest and widest 

 part the insect is lodged. 



teeth ; some of them are provided with a beak which 

 they employ like a pickaxe. The central hook is 

 fixed in the leaf as a fulcrum, and is bent and moved 

 about in various directions. 



Many of these miners are incapable of conducting 

 their operations, except in their native gallery ; when 

 removed to another leaf their instinct seems to for- 

 sake them: they appear unable to begin another 

 mine, and consequently perish. Others, however, 

 endowed with different instincts, have been known 

 to change the leaf on which they feed whenever the 



Aa2 



