HABITATIONS OF INSECTS. 259 



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 cylindri- 

 cal, 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 mecha- 

 nism it could possibly be made how an insect without fingers could con- 

 trive to bend a leaf into a roll, and to keep it in that form until fastened 

 with the silk which holds it together ? The following is the operation. 

 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. 1 



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

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

 rose-tree, apple, elm, and oak, on the under side of which they may 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 surround- 

 ing portion, it joins with silk so artfully that the seams are scarcely dis- 

 coverable 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 difficult 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 witness- 

 ing a short time since upon the alders in the Hull Botanic Garden, more 

 ingenious than their brethren, and willing to save the labour 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, mining into the 

 very crenatures between the two surfaces of the leaf, which, being joined 

 together at the edge, there form one seam of the case, and from their den- 

 tated figure give it a very singular appearance, not unlike that of some 



i Bonnet, ix. 188- 

 s 2 



