LEAF-CUTTERS. 243 



most commonly met with, and there are others which display 

 even a greater amount of ingenuity in their instinct-guided 

 operations. Of these there are many detailed descriptions ; 

 but, except as leaders to observation, these are somewhat 

 tedious, and, unless much illustrated, not easy to understand. 

 Were it even otherwise, our business, like that of the insect 

 artificers under review, is that of compression ; and, as these 

 little weavers shorten their silken threads to draw their leaves 

 into narrow compass, so must we manoeuvre with their inge- 

 nious labours to bring, even a few of them, within the limits 

 of a descriptive essay. 



Portions of leaves, as well as entire ones, are sometimes em- 

 ployed in the operations of leaf-rolling caterpillars, which, in 

 these instances, using their jaws with all the precision of well 

 directed scissors, manage to cut out, but without entirely cut- 

 ting off, a piece of material shaped exactly to their purpose. 

 A worker of this description is a little smooth greenish-white 

 caterpillar, which, out of a piece of sorrel leaf thus excised and 

 not detached, forms a sort of conical pyramid, composed of five 

 or six enwrapping folds. Having cut out the required seg- 

 ment, the cunning artificer rolls it slowly up by means of 

 threads attached to the surface of the leaf, " and then, having 

 cut in a different direction, sets the cone upright by weaving other 

 threads attached to the centre of the roll and the plane of the leaf, 

 upon which it throws the weight of its body"* After having de- 

 voured the interior folds of this ingeniously constructed cone, 



* Insect Architecture, p. 167; also Keaumur. 



