238 
DARWINISM 
CHAP. 
animals, while, in the immense majority of cases, the con¬ 
spicuous, 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. 1 
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 required for the purpose 
1 Nature, vol. iii. p. 147. 
