Sir Joseph Dalton Hooker. 



XI 



(M.L., vol. 1, p. 453). Though striving to arrange species according to their 

 affinity, it deals with them as existing facts. Hooker therefore proceeds on 

 the assumption that species are permanent, but guards himself by saying 

 that this was not to be " interpreted .... as a fixed and unalterable 

 opinion." 



In reviewing the facts of distribution in the Southern Hemisphere, he 

 insists on the inefficiency of known means of transport for seeds, and 

 expresses the belief, which he had only hinted at before, that the presence 

 of the same species in separate Antarctic islands could only be explained by 

 their having been parts of a continuous area now partially submerged. He 

 extends this theory to explain the presence of a South American element in 

 the Hew Zealand flora. 



In 1855 Hooker was appointed to the Kew Staff as Assistant Director, 

 and for the next thirty years of his life he remained attached to it. With 

 T. Thomson he had commenced a ' Flora Indica,' and the first and only 

 volume was published in this year. But it was projected on too vast a 

 scale to be practicable, and the work was only accomplished when resumed 

 in later life on a more restricted plan. The first attempt was not, however, 

 fruitless. It included an " Introductory Essay," which was published 

 separately. This contains a " Summary of Labours of Indian Botanists," 

 which is still indispensable, and a masterly " Sketch of the Physical 

 Features and Vegetation of the Provinces of India," which required sub- 

 stantially little modification at his hands fifty years later, when the whole 

 flora had been systematically worked out. 



The great problem which never ceased to occupy Hooker's mind from his 

 earliest work on the Antarctic flora was "the laws of the distribution of 

 plants." and he approached it by a purely inductive method. The ascertain- 

 ment of the facts must precede any attempt to theorise about them. He 

 would give no countenance to " loose theories on geographical distribution 

 and on the development of species " (Intr. Ess., ' Fl. Ind.,' p. 102). Though 

 acquainted with the progress of Darwin's speculations and constantly assisting 

 him with information, his attitude was one of continual criticism and reserve. 

 Darwin would accuse himself of " mere base subservience and terror of Hooker 

 and Co." (L.L.. vol. 2, p. 335). " Adios," he wrote to Hooker in 1858, "you 

 terrible worrier of poor theorists " (M.L., vol. 1, p. 105). Darwin's theory 

 must fit in with geographical distribution, and Darwin agreed that that 

 would be a test (L.L., vol. 2, p. 78). Meanwhile, Hooker more than once 

 insists " that progress in this branch of botany depends on an exact know- 

 ledge of species, genera, and families, and their affinities " (loc. eit, p. 103), 

 and to this he henceforth devoted himself. 



It is to be remarked that in this essay he expresses the opinion that the 

 principle of the struggle for existence amongst plants, the first enunciation 

 of which he attributes to Dean Herbert, had " never been sufficiently 

 appreciated " (p. 41). " Species in general do not grow where they like best, 

 but where they can best find room." The facts of Indian vegetation led him 



