ange. He
gave the finest expression that science has yet known--if it has known
it--of the kernel-idea of what is called "bathmism," the idea of an
"inherent growth-force"--and at the same time he held that "the way of
life powerfully reacts upon all form" and that the orderly growth of
form "yields to change from externally acting causes."

Besides Buffon, Erasmus Darwin, Lamarck, Treviranus, and Goethe,
there were other "pioneers of evolution," whose views have been often
discussed and appraised. Etienne Geoffroy Saint-Hilaire (1772-1884),
whose work Goethe so much admired, was on the whole Buffonian,
emphasising the direct action of the changeful _milieu_. "Species vary
with their environment, and existing species have descended by
modification from earlier and somewhat simpler species." He had a
glimpse of the selection idea, and believed in mutations or sudden
leaps--induced in the embryonic condition by external influences. The
complete history of evolution-theories will include many instances of
guesses at truth which were afterwards substantiated, thus the
geographer von Buch (1773-1853) detected the importance of the
Isolation factor on which Wagner, Romanes, Gulick and others have laid
great stress, but we must content ourselves with recalling one other
pioneer, the author of the _Vestiges of Creation_ (1844), a work which
passed through ten editions in nine years and certainly helped to
harrow the soil for Darwin's sowing. As Darwin said, "it did excellent
service in this country in calling attention to the subject, in
removing prejudice, and in thus preparing the ground for the reception
of analogous views."[24] Its author, Robert Chambers (1802-1871) was
in part a Buffonian--maintaining that environment moulded organisms
adaptively, and in part a Goethian--believing in an inherent
progressive impulse which lifted organisms from one grade of
organisation to another.

_As Regards Natural Selection_

The only thinker to whom Darwin was directly indebted, so far as the
theory of Natural Selection is concerned, was Malthus, and we may once
more quote the well-known passage in the Autobiography: "In October,
1838, that is, fifteen months after I had begun my systematic enquiry,
I happened to read for amusement 'Malthus on Population,' and being
well prepared to appreciate the struggle for existence which
everywhere goes on from long-continued observation of the habits of
animals and plants, it at once struc