CH. XVI.] THE CATERPILLAR. 277 



tube the portion of the leaf contained between two 

 indentations. The bottom of the tube is then closed 

 by another piece of leaf attached to it by means of 

 silken cords. 



Another tribe of caterpillars, equally numerous 

 with the leaf-rollers, may be termed leaf-benders. 

 Some of these give the leaf but a slig-ht bend, while 

 others bend it almost thoroughly. And so admirable 

 is the instinct with which they are endowed, that in 

 feeding they consume only a portion of the leaf; the 

 upper membrane and the nervures are left untouched, 

 which secures to them both a place of shelter and a 

 magazine of provisions. 



These caterpillars do not require to be accommo- 

 dated with a narrow case composed of many folds ; 

 they are content with one large curve, which is pro- 

 duced by a very curious process. The insect takes 

 advantage of that part of the edge of a leaf which 

 happens to be naturally somewhat bent : to this some 

 threads are attached; the other end of these threads 

 is fixed near the great nervure m the centre of the 

 leaf; owing to the natural bend of the leaf some 

 vacant space is interposed between these threads 

 and the surface. The insect mounts upon the 

 threads ; its weight increases the bend ; the edge of 

 the leaf is brought nearer the central nervure ; and 

 to keep it in this position, the animal spins and ap- 

 plies a new set of shorter cords. As the insect does 

 not want a narrow case, but merely a curve which 

 describes the segment of a large circle, it begins 



Aa 



