280 OBITUARY x 
writer remained unknown to naturalists until after 
the publication of the “ Origin of Species.” 
Darwin found in the doctrine of the selection of 
favourable variations by natural causes, which thus 
presented itself to his mind, not merely a probable 
theory of the origin of the diverse species of living 
forms, but that explanation of the phenomena of 
adaptation, which previous speculations had utterly 
failed to give. The process of natural selection is, 
in fact, dependent on adaptation—it is all one, 
whether one says that the competitor which sur- 
vives is the “ fittest” or the “ best adapted.” And 
it was a perfectly fair deduction that even the — 
most complicated adaptations might result from 
the summation of a long series of simple favour- 
able variations. 
Darwin notes as a serious defect in the first 
sketch of his theory that he had omitted to con- 
sider one very important problem, the solution of — 
which did not occur to him till some time after- 
wards. “This problem is the tendency in organic 
beings descended from the same stock to diverge 
in character as they become modified. ... The 
solution, as I believe, is that the modified offspring 
of all dominant and increasing forms tend to 
become adapted to many and highly diversified 
places in the economy of nature.” (1, p. 84.) 
It is curious that so much importance should be — 
attached to this supplementary idea. It seems — 
obvious that the theory of the origin of species 
