ciple--Mimicry in other orders of insects--Mimicry among the
vertebrata--Snakes--The rattlesnake and the cobra--Mimicry among
birds--Objections to the theory of mimicry--Concluding remarks
on warning colours and mimicry.

We have now to deal with a class of colours which are the very opposite
of those we have hitherto considered, since, instead of serving to
conceal the animals that possess them or as recognition marks to their
associates, they are developed for the express purpose of rendering the
species conspicuous. The reason of this is that the animals in question
are either the possessors of some deadly weapons, as stings or poison
fangs, or they are uneatable, and are thus so disagreeable to the usual
enemies of their kind that they are never attacked when their peculiar
powers or properties are known. It is, therefore, important that they
should not be mistaken for defenceless or eatable species of the same
class or order, since in that case they might suffer injury, or even
death, before their enemies discovered the danger or the uselessness of
the attack. They require some signal or danger-flag which shall serve as
a warning to would-be enemies not to attack them, and they have usually
obtained this in the form of conspicuous or brilliant coloration, very
distinct from the protective tints of the defenceless animals allied to
them.

_The Skunk as illustrating Warning Coloration._

While staying a few days, in July 1887, at the Summit Hotel on the
Central Pacific Railway, I strolled out one evening after dinner, and on
the road, not fifty yards from the house, I saw a pretty little white
and black animal with a bushy tail coming towards me. As it came on at a
slow pace and without any fear, although it evidently saw me, I thought
at first that it must be some tame creature, when it suddenly occurred
to me that it was a skunk. It came on till within five or six yards of
me, then quietly climbed over a dwarf wall and disappeared under a small
outhouse, in search of chickens, as the landlord afterwards told me.
This animal possesses, as is well known, a most offensive secretion,
which it has the power of ejecting over its enemies, and which
effectually protects it from attack. The odour of this substance is so
penetrating that it taints, and renders useless, everything it touches,
or in its vicinity. Provisions near it become uneatable, and clothes
saturated with it will retain the smell for seve