Sir Joseph Dalton Hooker. 



v 



1856 : " How strange, funny, and disgraceful that nearly all our great men 

 are in quarrels in couplets" (M.L., vol. 1, p. 90). With Hooker, the 

 "intimacy," which began in 1843, "ripened into feelings as near to those of 

 reverence for his life-work and character as is reasonable and proper " 

 (L.L., vol. 2, p. 20). Darwin, for his part, could say in 1862 : " For years I 

 have looked up to you as the man whose opinion I have valued more on any 

 scientific subject than anyone else in the world " (MX., vol. 2, p. 284). But 

 it would be a great error to suppose that the terms of the friendship were 

 merely those of mutual admiration. Writing to Lyell in 1866 Darwin said : 

 " His (Hooker's) mind is so acute and critical that I always expect to have a 

 torrent of objections to anything proposed : but he is so candid that he often 

 comes round in a year or two " (M.L., vol. 2, p. 138). The moral elevation of 

 character which made the friendship both possible and profitable is credit- 

 able to human nature ; but its service to science was deeper. This has been 

 admirably expressed by F. Darwin : " It should not be forgotten that .... 

 science owes much to this memorable friendship, since, without Hooker's aid, 

 Darwin's great work would hardly have been carried out on the botanical 

 side ; and Sir Joseph did far more than supply knowledge and guidance in 

 technical matters. Darwin owed to him a sympathetic and inspiring 

 comradeship which cheered and refreshed him to the end of his life " (M.L., 

 vol. 1, p. 39). 



Darwin and Hooker were both working towards evolution : but they started 

 from different points, and travelled on lines which only slowly converged. 

 At the beginning of the nineteenth century naturalists were still fettered by 

 the chains which Linnteus had forged for them. Species were " diversae 

 formse in principio creatse " ; they were permanent and immutable. A 

 variation was " planta mutata a caussa accidental! " ; it was not permanent, 

 " reducitur itaque in solo mutato." Species produce individuals which 

 therefore all trace to a common parentage, but do not vary ; " produxere 

 plures at sibi semper similes." Darwin tells us that, " when I was on board 

 the ' Beagle,' I believed in the permanence of species " (M.L., vol. 1, p. 367). 

 It was " the relationship between the living and the extinct mammifers in 

 South America " (L.L., vol. 2, p. 34) which first suggested organic evolution to 

 Darwin's mind, in the sense of the replacement in time of one allied organism 

 by another. It was the Galapagos that suggested to him "that the 

 inhabitants of the several islands had descended from each other, undergoing 

 modification in the course of their descent " (Variation, vol. 1, p. 10) ; this 

 was divergence in space. 



Hooker equally started with a belief in the permanence of species. But he 

 was confronted with another difficulty in the presence of the same species in 

 widely dissevered areas. This has been held to be irreconcilable with 

 Linnseus's dictum of a common parentage by writers as recent as the elder 

 Agassiz. Hooker, however (' Fl. Ant.' p. 368), definitely rejected the theory 

 of species having " multiple " or, as he called them, " sporadic " origins. The 

 explanation then must " be sought in some natural cause." For this there are 



