472 INSTINCT OF INSECTS. 



reside in a subcylindrical case — are still more remarka- 

 ble. This little caterpillar feeds upon the elm, the leaves 

 of which serve it at once for food and clothing. It eats 

 the parenchyma or inner pulp, burrowing between the 

 upper and under membranes, of portions of which cut 

 out, and properly sewed together, it forms its case. Its 

 usual plan is, to insinuate itself between the epidermal 

 membranes of the leaf, close to one of the edges. 

 Parallel with this it excavates a cavity of suitable form 

 and dimensions, gnawing the pulp even out of every pro- 

 jection of the serratures, but carefully avoiding to sepa- 

 rate the membranes at the very edge, which with a wise 

 saving of labour it intends should form one of the seams 

 of its coat ; and as the little miner is not embarrassed 

 with the removal of the excavated materials, which it 

 swallows as it proceeds, a cavity sufficiently large is but 

 the work of a few hours. It then lines it with silk, at 

 the same time pushing it into a more cylindrical shape ; 

 and lastly, cutting it off at the two ends and inner side, 

 it sews up the latter with such nicety that the suture is 

 scarcely discoverable ; and is now provided with a case 

 or coat exactly fitting its body, open at the two ends, by 

 one of which it feeds and by the other discharges its 

 excrement, having on one side a nicely-joined seam, and 

 the other — that which is commonly applied to its back 

 — composed of the natural marginal junction of the mem- 

 branes of the leaf 



Such are the ordinary operations of this insect, which, 

 when it is considered that the case is rather fusiform than 

 cylindrical ; that the end through which it eats is circu- 

 lar, and the other curiously three-cornered like a cocked- 

 hat; and that consequently its doth requires to be very 



