272 THE INSECT WORLD. 



admirably described all their little manoeuvres ; but we lack the 

 space to convey to the reader the result of his minute observations. 

 In fact, the leaf-rollers construct for themselves a sort of cylin- 

 drical cell, which receives light only through the two extremities. 

 The convenience of this green fresh habitation is, that its walls 

 furnish food to the animal which inhabits it. The caterpillar, thus 

 sheltered, sets to work to gnaw away at the end of the leaf which 

 it rolled first ; it then eats all the rolls it has made, up to the 

 very last. 



Reaumur found also rolls which had been formed of two or three 

 leaves rolled lengthwise, and he saw that the leaves which had 

 occupied the centre had been almost entirely eaten. He saw also 



Fig. 284. Leaf of sorrel, a portion of which is cut and rolled perpendicularly to the leaf. 



caterpillars which continued to eat while they were making their 

 habitation. Let us add that one of the ends of the roll is the opening 

 through which the caterpillar casts its excrement ; that the cater- 

 pillar can prepare itself a fresh roll, if it is turned out of the first ; 

 and, lastly, that it is in a rolled leaf that the caterpillar undergoes 

 its metamorphoses into a chrysalis and into a moth. 



Reaumur studied other leaf- rollers ; for instance, those which 

 roll the leaves of nettles and of sorrel. This last one works in a 

 manner which deserves to be mentioned. Its roll is of no particular 

 shape, but it is its position which is remarkable. It is set upon the 

 leaf like a ninepin (Fig. 284). The caterpillar has not only to 

 twist it up into a roll, but also to place it perpendicularly on the 

 leaf. 



Next to the rolling caterpillars, let us mention those which are 

 contented with folding the leaves. These caterpillars then lie in a 

 sort of flat box. Besides the rolling and folding caterpillars, there 

 are still those which bind up a good many leaves in one packet. 



