recognize have not been independently created, as such, but have descended,
like varieties, from other species. Varieties, on this view, are incipient
or possible species: species are varieties of a larger growth and a wider
and earlier divergence from the parent stock; the difference is one of
degree, not of kind.

The ordinary view--rendering unto Caesar the things that are
Caesar's--looks to natural agencies for the actual distribution and
perpetuation of species, to a supernatural for their origin.

The theory of Agassiz regards the origin of species and their present
general distribution over the world as equally primordial, equally
supernatural; that of Darwin, as equally derivative, equally natural.

The theory of Agassiz, referring as it does the phenomena both of origin
and distribution directly to the Divine will--thus removing the latter with
the former out of the domain of inductive science (in which efficient cause
is not the first, but the last word)--may be said to be theistic to excess.
The contrasted theory is not open to this objection. Studying the facts and
phenomena in reference to proximate causes, and endeavoring to trace back
the series of cause and effect as far as possible, Darwin's aim and
processes are strictly scientific, and his endeavor, whether successful or
futile, must be regarded as a legitimate attempt to extend the domain of
natural or physical science. For, though it well may be that "organic forms
have no physical or secondary cause," yet this can be proved only
indirectly, by the failure of every attempt to refer the phenomena in
question to causal laws. But, however originated, and whatever be thought
of Mr. Darwin's arduous undertaking in this respect, it is certain that
plants and animals are subject from their birth to physical influences, to
which they have to accommodate themselves as they can. How literally they