X 
The Botanical Work of Darwin . 
principally because of his irresistible desire to understand the 
machinery of living things. It is true that in elucidating the 
machinery he supplied the most brilliant evidence in favour 
of the validity of natural selection as the great moulding 
force in Nature. But I do not think this was his object, it 
was rather a by-product of work carried on for the love of 
doing it. It is true that he felt the importance of the 
evidence in regard to evolution, for he says : — c It will per- 
haps serve to show how natural history may be worked 
under the belief of the modification of species 1 .’ 
During the long years of the first period he was learning to 
know plants as he used them in the building of his theory ; 
and then the tables were turned, and the theory served him 
as a powerful engine to break still further into the secrets 
of plants, and the engine seemed all the more marvellously 
effective because he employed it on problems already half 
conquered in his earlier work. Instances of the pervasion of 
the second group of works by evolutionary characteristics 
will be given later. 
Evolutionary Period. 
I shall not attempt to deal at any length with the Botany 
of the evolutionary period ; the nature of the work may be 
fairly estimated by a study of the Origin, first edition, 1859 ; 
Animals and Plants, 1868 ; and the Life and Letters. Taking 
the Origin first, a striking feature is the use made of a mass 
of botanical facts in parts of the science in which he had no 
special first-hand knowledge. Mr. Huxley has pointed out 
that in Zoology, by the eight years given to the Cirripedes, 
he had made himself a master in the trade ; he knew the raw 
material, and could judge of the theoretical strain which that 
material would bear. But in Botany he had no such training. 
He had to test his theories on difficult problems in vegetable 
morphology, classification, and distribution, with an outfit of 
knowledge based almost entirely on reading, and on what he 
had learned from Henslow at Cambridge. 
1 Life and Letters, Yol. iii, p. 254. 
