196 Insect Architecture. 



An indefatigable observer, such as M. Reaumur, would 

 naturally follow up this discovery ; and 'he has accordingly 

 given us a memoir of the pondweed tent-maker, distinguished 

 by his usual minute accuracy. 



In order to make a new habitation, the caterpillar fastens 

 itself on the under side of a leaf of the Potamogeton. With 

 its mandibles it pierces some part of this leaf, and afterwards 

 gradually gnaws a curved line, marking the form of the piece 

 which it wishes to detach. When the caterpillar has cut off, 

 as from a piece of cloth, a patch of leaf of the size and 

 shape suited to its purpose, it is provided with half of the 

 materials requisite for making a tent. It takes hold of this 

 piece by its mandibles, and conveys it to the situation on 

 the under side of its own or another leaf, whichever is found 

 most appropriate. It is there disposed in such a manner 

 that the under part of the patch the side which was the 

 under part of the entire leaf is turned towards the under 

 part of the new leaf, so that the inner walls of the cell or 

 tent are always made by the under part of two portions of 

 leaf. The leaves of the potamogeton are a little concave on 

 the under side ; and thus the caterpillar produces a hollow 

 cell, though the rims are united. 



The caterpillar secures the leaf in its position by threads 

 of white silk. It then weaves in the cavity a cocoon, which 

 is somewhat thin, but of very close tissue. There it shuts 

 itself up, to appear again only in the form of the perfect 

 insect, and is soon transformed into a chrysalis. In this 

 cocoon of silk no point touches the water ; whilst the tent 

 of leaves, lined with silk, has been constructed underneath 

 the water. This fact proves that the caterpillar has a particu- 

 lar art by which it repels the water from between the leaves. 



When the caterpillar, which has thus conveyed and 

 disposed a patch of leaf against another leaf, is not ready to 

 be transformed into a chrysalis, it applies itself to make a 

 tent or habitation which it may carry everywhere about with 

 it. It begins by slightly fixing the piece against the perfect 

 leaf, leaving intervals all round, between the piece and leaf, 

 at which it may project its head. The piece which it has 



