54 LETTERS ON ENTOMOLOGY. 
exactly in the same way as the domestic sort, 
and their habits are not so rich and varied, but 
their ingenuity is perhaps still more worthy of 
admiration. 
Though they are very common, they are seldom 
found but by those who know where to look, as 
they attach themselves to the under part of the 
leaf, and remain stationary ; the part to which 
they hang is usually withered. Their garments 
are also of the colour of dried leaves, and thus 
they escape notice : they are found in oaks, elms, 
pear and apple-trees, and rose-trees, but rarely 
in the last, and each tree has a different kind. 
As they are caterpillars, the body is long and 
round like those which eat cloth, but their gar- 
ments are of a different shape. They are formed 
like a triangular tube, smooth and hard, and 
much larger than the insect, to give it room to 
turn round. The manner in which they accom- 
plish the formation of them is very curious. 
The substance on which they feed is the pulp 
between the upper and lower membrane of the 
leaf; and when they have eaten away a sufficient 
space, they lie between the two membranes, in 
one of which they are to clothe themselves, and 
cut it out as a tailor cuts out his cloth; and 
though the form of the separate pieces is not 
