likely, therefore, to know that Lamarck drew very largely from
Buffon, and probably also from Dr. Erasmus Darwin, and that this
last-named writer, though essentially original, was founded upon
Buffon, who was greatly more in advance of any predecessor than any
successor has been in advance of him.

We did not know, then, that according to the earlier writers the
variations whose accumulation results in species were not fortuitous
and definite, but were due to a known principle of universal
application--namely, "sense of need"--or apprehend the difference
between a theory of evolution which has a backbone, as it were, in
the tolerably constant or slowly varying needs of large numbers of
individuals for long periods together, and one which has no such
backbone, but according to which the progress of one generation is
always liable to be cancelled and obliterated by that of the next.
We did not know that the new theory in a quiet way professed to tell
us less than the old had done, and declared that it could throw
little if any light upon the matter which the earlier writers had
endeavoured to illuminate as the central point in their system. We
took it for granted that more light must be being thrown instead of
less; and reading in perfect good faith, we rose from our perusal
with the impression that Mr. Darwin was advocating the descent of all
existing forms of life from a single, or from, at any rate, a very
few primordial types; that no one else had done this hitherto, or
that, if they had, they had got the whole subject into a mess, which
mess, whatever it was--for we were never told this--was now being
removed once for all by Mr. Darwin.

The evolution part of the story, that is to say, the fact of
evolution, remained in our minds as by far the most prominent feature