e alive. One species, which was
brought me in Borneo, was covered with delicate semitransparent green
foliations, exactly resembling the hepaticae which cover pieces of
rotten stick in the damp forests. Others resemble dead leaves in all
their varieties of colour and form; and to show how perfect is the
protection obtained and how important it is to the possessors of it, the
following incident, observed by Mr. Belt in Nicaragua, is most
instructive. Describing the armies of foraging ants in the forest which
devour every insect they can catch, he says: "I was much surprised with
the behaviour of a green leaf-like locust. This insect stood immovably
among a host of ants, many of which ran over its legs without ever
discovering there was food within their reach. So fixed was its
instinctive knowledge that its safety depended on its immovability, that
it allowed me to pick it up and replace it among the ants without making
a single effort to escape. This species closely resembles a green
leaf."[70]

Caterpillars also exhibit a considerable amount of detailed resemblance
to the plants on which they live. Grass-feeders are striped
longitudinally, while those on ordinary leaves are always striped
obliquely. Some very beautiful protective resemblances are shown among
the caterpillars figured in Smith and Abbott's _Lepidopterous Insects of
Georgia_, a work published in the early part of the century, before any
theories of protection were started. The plates in this work are most
beautifully executed from drawings made by Mr. Abbott, representing the
insects, in every case, on the plants which they frequented, and no
reference is made in the descriptions to the remarkable protective
details which appear upon the plates. We have, first, the larva of
Sphinx fuciformis feeding on a plant with linear grass-like leaves and
small blue flowers; and we find the insect of the same green as the
leaves, striped longitudinally in accordance with the linear leaves, and
with the head blue corresponding both in size and colour with the
flowers. Another species (Sphinx tersa) is represented feeding on a
plant with small red flowers situated in the axils of the leaves; and
the larva has a row of seven red spots, unequal in size, and
corresponding very closely with the colour and size of the flowers. Two
other figures of sphinx larvae are very curious. That of Sphinx
pampinatrix feeds on a wild vine (Vitis indivisa), having green
tendrils, and in