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

66 f~MIMICRY, AND OTHER PROTECTIVE
cats, horses, dogs, and cattle, white poultry, pigeons,
turkeys, and ducks, and white rabbits. Some of these
animals have been domesticated for a long period,
others only for a few centuries; but in almost every
case in which an animal has been thoroughly domesticated, parti-coloured and white varieties are produced
and become permanent.
It is also well known that animals in a state of nature
produce white varieties occasionally. Blackbirds, starlings, and crows are occasionally seen white, as well as
elephants, deer, tigers, hares, moles, and many other
animals; but in no case is a permanent white race
produced. Now there are no statistics to show that
the normal-coloured parents produce white offspring
oftener under domestication than in a state of nature,
and we have no right to make such an assumption if
the facts can be accounted for without it. But if the
colours of animals do really, in the various instances
already adduced, serve for their concealment and preservation, then white or any other conspicuous colour
must be hurtful, and must in most cases shorten an
animal's life. A white rabbit would be more surely the
prey of hawk or buzzard, and the white mole, or field
mouse, could not long escape from the vigilant owl.
So, also, any deviation from those tints best adapted
to conceal a carnivorous animal would render the pursuit of its prey much more difficult, would place it at
a disadvantage among its fellows, and in a time of
scarcity would probably cause it to starve to death.
On the other hand, if an animal spreads from a