208 GEOMETRID^. 
of time. This, together with their obscure colours, 
and the warts which their bodies exhibit, renders 
it often quite difficult to distinguish them from 
twigs of the trees on which they feed. They feed 
on the leaves of various trees and plants, and have 
the instinct, when alarmed, of dropping down from 
the leaves, and suspending themselves by a thread, 
which enables them to remount when the danger 
is past. The chrysalides are either naked and sus- 
pended by the tail, or enclosed in a very slender 
cocoon, which is rarely subterraneous, and oft-times 
placed amongst dry leaves, &c." * 
"We have numerous species in Britain, many of 
them very agreeably adorned. The foreign species 
are also very numerous, but none of them attain a 
large size. 
* Westwood's Modern Class, of Insects, vol. ii. p. 507. 
