388 



HABITATIONS OT INSECTS. 



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 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 

 caterpillar 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 proceeds 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 fabricat- 

 ing the habitations 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 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 



I Bonnet, ix. 188. 



