294 HABITATIONS OF INSECTS. 



the plants on which they feed. Some of these merely connect together 

 with a few silken threads several leaves so as to form an irregular packet, 

 in the centre of which the little hermit lives. Others confine themselves 

 to a single leaf, of which they simply fold one part over the other. A 

 third description form and inhabit a sort of roll, by some species made 

 cylindrical, by others conical, resembling the papers into which grocers 

 put their sugar, and as accurately constructed ; only there is an opening 

 left at the smaller extremity for the egress of the insect in case of need. 

 If you were to see one of these rolls, you would immediately ask by what 

 mechanism it could possibly be made — how an insect without fingers could 

 contrive to bend a leaf into a roll, and to keep it in that form until fas- 

 tened with the silk which holds it together ? The following is the opera- 

 tion. The little caterpillar first fixes a series of silken cables from one side 

 of the leaf to the other. She next pulls at these cables with her feet ; and 

 when she has forced the sides to approach, she fastens them together with 

 shorter threads of silk. If the insect finds that one of the larger nerves 

 of the leaf is so strong as to resist her efforts, she weakens it by gnawing 

 it here and there half through. What engineer could act more sagaciously ? 

 To form one of the conical or horn-shaped rolls, which are not composed 

 of a whole leaf, but of a long triangular portion cut out of the edge, some 

 other manoeuvres are requisite. Placing herself upon the leaf, the cater- 

 pillar cuts out with her jaws the piece which is to compose her roll. She 

 does not, however, entirely detach it : it would then want a base. She 

 detaches that part only which is to form the contour of the horn. This 

 portion is a triangular strap, which she rolls as she cuts. When the body 

 of the horn is finished, as it is intended to be fixed upon the leaf in nearly 

 an upright position it is necessary to elevate it. To effect this, she pro- 

 ceeds as we should with an inclined obelisk. She attaches threads or 

 little cables towards the point of the pyramid, and raises it by the weight 

 of her body.^ 



A still greater degree of dexterity is manifested in fabricating the hab- 

 itations of the larvae of some other moths which feed on the leaves of the 

 rose-tree, apple, elm, and oak, on the underside of which they njay in 

 summer be often found. These form an oblong cavity in the interior of 

 a leaf by eating the parenchyma between the two membranes composing 

 its upper and under side, which, after having detached them from the sur- 

 rounding portion, it joins with silk so artfully that the seams are scarcely 

 discoverable even with a lens, so as to compose a case or horn, cylindrical 

 in the middle, its anterior orifice circular, its posterior triangular. Were 

 this dwelling cylindrical in every part, the form of the two pieces that 

 compose it would be very simple ; but the different shape of the two ends 

 renders it necessary that each side should have peculiar and dissimilar 

 curvatures ; and Reaumur assures us, that these are as complex and diffi- 

 cult to imitate as the contours of the pieces of cloth that compose the 

 back of a coat. Some of this tribe, whose proceedings I had the pleasure 

 of witnessing a short time since upon the alders in the Hull Botanic Gar- 

 den, more ingenious than their brethren, and willing to save the labor of 

 sewing up two seams in their dwelling, insinuate themselves near the edge 

 of a leaf instead of in its middle. Here they form their excavation, 



» Bonnet, ix. 188. 



