win gave a brief preliminary account
of his ideas as to the origin of species, and said that geographical
distribution must be one of the tests of their validity. ("Life and
Letters", II. page 78.) What is of supreme interest is that it was also
their starting-point. He tells us:--"When I visited, during the voyage
of H.M.S. "Beagle", the Galapagos Archipelago,... I fancied myself
brought near to the very act of creation. I often asked myself how these
many peculiar animals and plants had been produced: the simplest answer
seemed to be that the inhabitants of the several islands had descended
from each other, undergoing modification in the course of their
descent." ("The Variation of Animals and Plants" (2nd edition), 1890, I.
pages 9, 10.) We need not be surprised then, that in writing in 1845
to Sir Joseph Hooker, he speaks of "that grand subject, that almost
keystone of the laws of creation, Geographical Distribution." ("Life and
Letters", I. page 336.)

Yet De Candolle was, as Bentham saw, unconsciously feeling his way,
like Lyell, towards evolution, without being able to grasp it. They both
strove to explain phenomena by means of agencies which they saw actually
at work. If De Candolle gave up the ultimate problem as insoluble:--"La
creation ou premiere formation des etres organises echappe, par sa
nature et par son anciennete, a nos moyens d'observation" (Loc. cit.
page 1106.), he steadily endeavoured to minimise its scope. At least
half of his great work is devoted to the researches by which he
extricated himself from a belief in species having had a multiple
origin, the view which had been held by successive naturalists from
Gmelin to Agassiz. To account for the obvious fact that species
constantly occupy dissevered areas, De Candolle made a minute study of
their means of transport. This was found to dispose of the vast majority
of cases, and the remainder he accounted for by geographical change.
(Loc. cit. page 1116.)

But Darwin strenuously objected to invoking geographical change as a
solution of every difficulty. He had apparently long satisfied himself
as to the "permanence of continents and great oceans." Dana, he tells us
"was, I believe, the first man who maintained" this ("Life and Letters",
III. page 247. Dana says:--"The continents and oceans had their general
outline or form defined in earliest time," "Manual of Geology", revised
edition. Philadelphia, 1869, page 732. I have no access to an earlier