mitating and the imitated forms; that is to say, in some cases the
zoological affinity is not closer than ordinal, and therefore cannot
possibly be ascribed to kinship. Like all the other branches of the
general subject of protective resemblance in form or colouring, this
branch has already been so largely illustrated by previous writers,
that, as in the previous cases, I need only give one or two examples.
Those which I choose are chosen on account of the colours concerned not
being highly varied or brilliant, and therefore lending themselves to
less ineffectual treatment by wood-engraving than is the case where
attempts are made to render by this means even more remarkable
instances. (Figs. 113, 114, 115.)

[Illustration: FIG. 113.--Three cases of mimicry. Drawn from nature:
first two pairs nat. size, last pair 2/3 (_R. Coll. Surg. Mus._).]

[Illustration: FIG. 114.--Two further cases of mimicry; flies
resembling a wasp in the one and a bee in the other. Drawn from
nature: nat. size (_R. Coll. Surg. Mus._).]

[Illustration: FIG. 115.--A case of mimicry where a non-venomous
species of snake resembles a venomous one. Drawn from nature: 1/3
nat. size (_R. Coll. Surg. Mus._).]

It is surely apparent, without further comment, that it is impossible to
imagine stronger evidence in favour of natural selection as a true cause
in nature, than is furnished by this culminating fact in the matter of
protective resemblance, whereby it is shown that a species of one
genus, family, or even order, will accurately mimic the appearance of a
species belonging to another genus, family, or order, so as to deceive
its natural enemies into mistaking it for a creature of so totally
different a kind. And it must be added that while this fact of mimicry
is of extraordinarily frequent occurrence, there can be no possibility
of our mistaking its purpose. For the fact is never observable except in
the case of species which occupy the same area or district.

Such being what appears to me the only reasonable view of the matter, I
will now conclude this chapter on the evidences of natural selection as
at all events the main factor of organic evolution, by simply adding
illustrations of two further cases of mimicry, which are perhaps even
more remarkable than any of the foregoing examples. The first of the two
(Fig. 115) speaks for itself. The second will be rendered intelligible
by the following few words of explan