justifies us completely in the anticipation, that when the still
lower Eocene deposits, and those which belong to the Cretaceous epoch,
have yielded up their remains of ancestral equine animals, we shall
find, first, a form with four complete toes and a rudiment of the
innermost or first digit in front, with, probably, a rudiment of the
fifth digit in the hind foot; [4] while, in still older forms, the series
of the digits will be more and more complete, until we come to the
five-toed animals, in which, if the doctrine of evolution is well
founded, the whole series must have taken its origin.
That is what I mean by demonstrative evidence of evolution. An inductive
hypothesis is said to be demonstrated when the facts are shown to be in
entire accordance with it. If that is not scientific proof, there are
no merely inductive conclusions which can be said to be proved. And the
doctrine of evolution, at the present time, rests upon exactly as secure
a foundation as the Copernican theory of the motions of the heavenly
bodies did at the time of its promulgation. Its logical basis is
precisely of the same character--the coincidence of the observed facts
with theoretical requirements.
The only way of escape, if it be a way of escape, from the conclusions
which I have just indicated, is the supposition that all these different
equine forms have been created separately at separate epochs of time;
and, I repeat, that of such an hypothesis as this there neither is, nor
can be, any scientific evidence; and, assuredly, so far as I know, there
is none which is supported, or pretends to be supported, by evidence
or authority of any other kind. I can but think that the time will come
when such suggestions as these, such obvious attempts to escape the
force of demonstration, will be put upon the same footing as the
supposition made by some writers, who are I believe not completely
extinct at present, that fossils are mere simulacra, are no indications
of the former existence of the animals to which they seem to belong;
but that they are either sports of nature, or special creations,
intended--as I heard suggested the other day--to test our faith.
In fact, the whole evidence is in favour of evolution, and there is none
against it. And I say this, although perfectly well aware of the
seeming difficulties which have been built up upon what appears to the
uninformed to be a solid foundation. I meet constantly with the argument
that the
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