h not very closely allied, they have each the same red and black
colours, and are very distinct from all the other butterflies of their
respective countries. There is reason to believe also that many of the
brilliantly coloured and weak-flying diurnal moths, like the fine
tropical Agaristidae and burnet-moths, are similarly protected, and that
their conspicuous colours serve as a warning of inedibility. The common
burnet-moth (Anthrocera filipendula) and the equally conspicuous
ragwort-moth (Euchelia jacobeae) have been proved to be distasteful to
insect-eating creatures.

The most interesting and most conclusive example of warning coloration
is, however, furnished by caterpillars, because in this case the facts
have been carefully ascertained experimentally by competent observers.
In the year 1866, when Mr. Darwin was collecting evidence as to the
supposed effect of sexual selection in bringing about the brilliant
coloration of the higher animals, he was struck by the fact that many
caterpillars have brilliant and conspicuous colours, in the production
of which sexual selection could have no place. We have numbers of such
caterpillars in this country, and they are characterised not only by
their gay colours but by not concealing themselves. Such are the mullein
and the gooseberry caterpillars, the larvae of the spurge hawk-moth, of
the buff-tip, and many others. Some of these caterpillars are
wonderfully conspicuous, as in the case of that noticed by Mr. Bates in
South America, which was four inches long, banded across with black and
yellow, and with bright red head, legs, and tail. Hence it caught the
eye of any one who passed by, even at the distance of many yards.

Mr. Darwin asked me to try and suggest some explanation of this
coloration; and, having been recently interested in the question of the
warning coloration of butterflies, I suggested that this was probably a
similar case,--that these conspicuous caterpillars were distasteful to
birds and other insect-eating creatures, and that their bright
non-protective colours and habit of exposing themselves to view, enabled
their enemies to distinguish them at a glance from the edible kinds and
thus learn not to touch them; for it must be remembered that the bodies
of caterpillars while growing are so delicate, that a wound from a
bird's beak would be perhaps as fatal as if they were devoured.[93] At
this time not a single experiment or observation had been made on th