274 NATURAL HISTORY. CH. XVI 



tain the leaf in this position, which it again pulls 

 towards itself; and repeats the operation till it has 

 bent the leaf in its whole direction. It now begins 

 again, placing the threads farther back upon the 

 bent part of the leaf, and by proceeding in this 

 manner, rolls it up : when it has finished this busi- 

 ness, it strengthens the whole by fastening the ends 

 of the leaf together. The habitation thus formed, 

 is a kind of hollow cylinder, open to the light at 

 both ends, the sides of it affording the insect both 

 food and protection : for within it the creature feeds 

 in safety. In the same case it also undergoes its 

 transformation : at the approach of this change the 

 creature lines the rolled leaf with silk, that the 

 rough parts of it may not injure the tender chrysalis. 



Sometimes the leaf which is to be rolled up hap- 

 pens to be thick and its nervures strong ; in this 

 case the insect eats down the prominent part of the 

 nervures and levels them with the surface of the 

 leaf; not, however, throughout the whole of their 

 length, but a bit here and a bit there, leaving the 

 intervals entire. The, parts thus attacked and con- 

 sumed appeared to Reaumur to correspond both in 

 number and situation with the points in which the 

 leaf was to be curved in order to begin a new turn. 

 The leaf of the oak being deeply notched, its in- 

 equalities occasionally project so much, that it is 

 difficult to bring them within the curve of the rest 

 of the leaf. A thread tied to one of these project- 

 ing points merely bends the edge a little, leaving the 

 rest nearly flat. A human mechanic would cut off 

 this inconvenient superfluity; the caterpillar effects 

 that which amounts to the same thing ; it fixes it 

 with a thousand threads to the side of the leaf; and 

 then works it with its head into a round form. 



The insect proceeds in this manner to roll the leaf, 

 until it has encased itself in four or five folds. And 

 in addition to the silken bands used to secure these 

 folds longitudinally, a couple are tied to one or both 



