e
results completely confirm my original suggestion. In almost every case
the protectively coloured larvae have been greedily eaten by all kinds
of insectivorous animals, while, in the immense majority of cases, the
conspicuous, hairy, or brightly coloured larvae have been rejected by
some or all of them. In some instances the inedibility of the larvae
extends to the perfect insect, but not in others. In the former cases
the perfect insect is usually adorned with conspicuous colours, as the
burnet and ragwort moths; but in the case of the buff-tip, the moth
resembles a broken piece of rotten stick, yet it is partly inedible,
being refused by lizards. It is, however, very doubtful whether these
are its chief enemies, and its protective form and colour may be needed
against insectivorous birds or mammals.

Mr. Samuel H. Scudder, who has largely bred North American butterflies,
has found so many of the eggs and larvae destroyed by hymenopterous and
dipterous parasites that he thinks at least nine-tenths, perhaps a
greater proportion, never reach maturity. Yet he has never found any
evidence that such parasites attack either the egg or the larva of the
inedible Danais archippus, so that in this case the insect is
distasteful to its most dangerous foes in all the stages of its
existence, a fact which serves to explain its great abundance and its
extension over almost the whole world.[96]

One case has been found of a protectively coloured larva,--one,
moreover, which in all its habits shows that it trusts to concealment to
escape its enemies--which was yet always rejected by lizards after they
had seized it, evidently under the impression that from its colour it
would be eatable. This is the caterpillar of the very common moth Mania
typica; and Mr. Poulton thinks that, in this case, the unpleasant taste
is an incidental result of some physiological processes in the organism,
and is itself a merely useless character. It is evident that the insect
would not conceal itself so carefully as it does if it had not some
enemies, and these are probably birds or small mammals, as its
food-plants are said to be dock and willow-herb, not suggestive of
places frequented by lizards; and it has been found by experiment that
lizards and birds have not always the same likes and dislikes. The case
is interesting, because it shows that nauseous fluids sometimes occur
sporadically, and may thus be intensified by natural selection when
require