On the Genesis of Species | Page 6

Finally, by this theory--and as yet by this alone--can any explanation be
given of that extraordinary phenomenon which is metaphorically

termed mimicry. Mimicry is a close and striking, yet superficial
resemblance borne by some animal or plant to some other, perhaps very
different, animal or plant. The "walking leaf" (an insect belonging to
the grasshopper and cricket order) is a well-known and conspicuous
instance of the assumption by an animal of the appearance of a
vegetable structure (see illustration on p. 35); and the bee, fly, and
spider orchids are familiar examples of a converse resemblance. Birds,
butterflies, reptiles, and even fish, seem to bear in certain instances a
similarly striking resemblance to other birds, butterflies, reptiles, and
fish, of altogether distinct kinds. The explanation of this matter which
"Natural Selection" offers, as to animals, is that certain varieties of {9}
one kind have found exemption from persecution in consequence of an
accidental resemblance which such varieties have exhibited to animals
of another kind, or to plants; and that they were thus preserved, and the
degree of resemblance was continually augmented in their descendants.
As to plants, the explanation offered by this theory might perhaps be
that varieties of plants which presented a certain superficial
resemblance in their flowers to insects, have thereby been helped to
propagate their kind, the visit of certain insects being useful or
indispensable to the fertilization of many flowers.
We have thus a whole series of important facts which "Natural
Selection" helps us to understand and co-ordinate. And not only are all
these diverse facts strung together, as it were, by the theory in question;
not only does it explain the development of the complex instincts of the
beaver, the cuckoo, the bee, and the ant, as also the dazzling brilliancy
of the humming-bird, the glowing tail and neck of the peacock, and the
melody of the nightingale; the perfume of the rose and the violet, the
brilliancy of the tulip and the sweetness of the nectar of flowers; not
only does it help us to understand all these, but serves as a basis of
future research and of inference from the known to the unknown, and it
guides the investigator to the discovery of new facts which, when
ascertained, it seems also able to co-ordinate.[6] Nay, "Natural
Selection" seems capable of application not only to the building up of
the smallest and most insignificant organisms, but even of extension
beyond the biological domain altogether, so as possibly to have relation
to the stable equilibrium of the solar system{10} itself, and even of the

whole sidereal universe. Thus, whether this theory be true or false, all
lovers of natural science should acknowledge a deep debt of gratitude
to Messrs. Darwin and Wallace, on account of its practical utility. But
the utility of a theory by no means implies its truth. What do we not
owe, for example, to the labours of the Alchemists? The emission
theory of light, again, has been pregnant with valuable results, as still is
the Atomic theory, and others which will readily suggest themselves.
With regard to Mr. Darwin (with whose name, on account of the noble
self-abnegation of Mr. Wallace, the theory is in general exclusively
associated), his friends may heartily congratulate him on the fact that
he is one of the few exceptions to the rule respecting the
non-appreciation of a prophet in his own country. It would be difficult
to name another living labourer in the field of physical science who has
excited an interest so widespread, and given rise to so much praise,
gathering round him, as he has done, a chorus of more or less
completely acquiescing disciples, themselves masters in science, and
each the representative of a crowd of enthusiastic followers.
Such is the Darwinian theory of "Natural Selection," such are the more
remarkable facts which it is potent to explain, and such is the reception
it has met with in the world. A few words now as to the reasons for the
very widespread interest it has awakened, and the keenness with which
the theory has been both advocated and combated.
The important bearing it has on such an extensive range of scientific
facts, its utility, and the vast knowledge and great ingenuity of its
promulgator, are enough to account for the heartiness of its reception
by those learned in natural history. But quite other causes have
concurred to produce the general and higher degree of interest felt in
the theory beside the readiness with which it harmonizes with
biological facts. These latter could only be appreciated by physiologists,
zoologists, and botanists; whereas the Darwinian theory, so novel and
so startling, has found a {11} cloud of advocates and opponents beyond
and outside the world of physical science.
In the first place, it was inevitable that