The Darwinian Hypothesis | Page 6

animal or plants (witness our recent examples
from the work of Sir Emerson Tennent, on Ceylon), and yet they have
almost always a sort of general family resemblance to the animals and
plants of the nearest mainland. On the other hand, there is hardly a
species of fish, shell, or crab common to the opposite sides of the
narrow isthmus of Panama. Wherever we look, then, living nature
offers us riddles of difficult solution, if we suppose that what we see is
all that can be known of it.
But our knowledge of life is not confined to the existing world.
Whatever their minor differences, geologists are agreed as to the vast
thickness of the accumulated strata which compose the visible part of
our earth, and the inconceivable immensity of the time of whose lapse
they are the imperfect, but the only accessible witnesses. Now,
throughout the greater part of this long series of stratified rocks are
scattered, sometimes very abundantly, multitudes of organic remains,
the fossilized exuviae of animals and plants which lived and died while
the mud of which the rocks are formed was yet soft ooze, and could
receive and bury them. It would be a great error to suppose that these

organic remains were fragmentary relics. Our museums exhibit fossil
shells of immeasurable antiquity, as perfect as the day they were
formed, whole skeletons without a limb disturbed--nay, the changed
flesh, the developing embryos, and even the very footsteps of primieval
organisms. Thus the naturalist finds in the bowels of the earth species
as well defined as, and in some groups of animals more numerous than,
those that breathe the upper air. But, singularly enough, the majority of
these entombed species are wholly distinct from those that now live.
Nor is this unlikeness without its rule and order. As a broad fact, the
further we go back in time the less the buried species are like existing
forms; and the further apart the sets of extinct creatures are the less they
are like one another. In other words, there has been a regular succession
of living beings, each younger set being in a very broad and general
sense somewhat more like those which now live.
It was once supposed that this succession had been the result of vast
successive catastrophes, destructions, and re-creations 'en masse'; but
catastrophes are now almost eliminated from geological, or at least
palaeontological speculation; and it is admitted on all hands that the
seeming breaks in the chain of being are not absolute, but only relative
to our imperfect knowledge; that species have replaced species, not in
assemblages, but one by one; and that, if it were possible to have all the
phenomena of the past presented to us, the convenient epochs and
formations of the geologist, though having a certain distinctness, would
fade into one another with limits as undefinable as those of the distinct
and yet separable colours of the solar spectrum.
Such is a brief summary of the main truths which have been established
concerning species. Are these truths ultimate and irresolvable facts, or
are their complexities and perplexities the mere expressions of a higher
law?
A large number of persons practically assume the former position to be
correct. They believe that the writer of the Pentateuch was empowered
and commissioned to teach us scientific as well as other truth, that the
account we find there of the creation of living things is simply and
literally correct, and that anything which seems to contradict it is, by
the nature of the case, false. All the phenomena which have been
detailed are, on this view, the immediate product of a creative fiat and
consequently are out of the domain of science altogether.

Whether this view prove ultimately to be true or false, it is, at any rate,
not at present supported by what is commonly regarded as logical proof,
even if it be capable of discussion by reason; and hence we consider
ourselves at liberty to pass it by, and to turn to those views which
profess to rest on a scientific basis only, and therefore admit of being
argued to their consequences. And we do this with the less hesitation as
it so happens that those persons who are practically conversant with the
facts of the case (plainly a considerable advantage) have always
thought fit to range themselves under the latter category.
The majority of these competent persons have up to the present time
maintained two positions,--the first, that every species is, within certain
defined or definable limits, fixed and incapable of modification; the
second, that every species was originally produced by a distinct
creative act. The second position is obviously incapable of proof or
disproof, the direct operations of the Creator not being subjects of
science; and it must therefore