Contributions to the theory of natural selection. A series of essays ... By Alfred Russel Wallace ...

RESEiMBLYVCES AMONiG AN-ItLS. 69
cal modifications might often produce the extinction
of a race just as it was approaching perfection, and a
hundred checks of which we can know nothing may
have retarded the progress towards perfect adaptation;
so that we can hardly wonder at there being so few
cases in which a completely successful result has been
attained as shown by the abundance and wide diffusion
of the creatures so protected.
Objection that Colour, as being dangerous, should not exist
in Nature.
It is as well here to reply to an objection that will
no doubt occur to many readers-that if protection is
so useful to all animals, and so easily brought about
by variation and survival of the fittest, there ought
to be no conspicuously-coloured creatures; and they
will perhaps ask how we account for the brilliant
birds, and painted snakes, and gorgeous insects, that
occur abundantly all over the world. It will be advisable to answer this question rather fully, in order that
we may be prepared to understand the phenomena of'lmimicry," which it is the special object of this paper
to illustrate and explain.
The slightest observation of the life of animals will
show us, that they escape from their enemies and
obtain their food in an infinite number of ways; and
that their varied habits and instincts are in every case
adapted to the conditions of their existence. The
porcupine and the hedgehog have a defensive armour
that saves them from the attacks of most animals.