Iv. ] PREDATORY PLANTS. 67 
Pitcher-plants, described and figured in the following 
chapter, catch and kill large numbers of small insects, 
and there is no doubt that some sort of digestive 
process goes on in the remarkable vessels formed by 
the leaves, and that the plant receives benefit from 
its destructive habits. 
The exquisite sensitiveness of Dionga and Drosera 
is remarkable, and there is something almost ludi- 
crous in the notion of a plant getting its living by . 
false pretences, for undoubtedly Drosera does this. 
We ourselves have no doubt that insects mistake the 
round leaf, with its dewy-knobbed red hairs, for a 
flower, and visit it in the hope of getting honey for 
their pains. Yet there should be nothing surprising 
in such mimicry, for it is carried on to a large extent 
among animals. The Bamboo-insect and the Leaf- 
insect imitate bamboo and leaves to perfection simply 
for the purpose of approaching, or lying in wait for, 
their prey without exciting suspicion. With many 
butterflies and moths such mimicry takes the form of 
protective colouring, so as to render them indistin- 
suishable when on a tree-trunk, a lichen-covered 
wall, or certain flowers. It is the same principle by 
which frogs and toads, and many fishes, are able to 
reflect from their skins the hues of surrounding 
objects, and thus, on a cursory glance, to remain 
invisible to their enemies, 
