The Descent of Man

and moths were also given to some lizards and
frogs, by Mr. A. Butler, and were rejected,
though other kinds were eagerly eaten. Thus
the probability of Mr. Wallace's view is confirmed,
namely, that certain caterpillars have been
made conspicuous for their own good, so as to
be easily recognised by their enemies, on nearly
the same principle that poisons are sold in coloured
bottles by druggists for the good of man.
We cannot, however, at present thus explain
the elegant diversity in the colours of many
caterpillars; but any species which had at some
former period acquired a dull, mottled, or striped
appearance, either in imitation of surrounding
objects, or from the direct action of climate,
etc., almost certainly would not become uniform
in colour, when its tints were rendered
intense and bright; for in order to make a caterpillar
merely conspicuous, there would be no
selection in any definite direction.