ASSISTANT AT KEW 353 



Thus at length his own and his father's highest hopes were 

 realised. Till Sir William's death ten years later, leaving his 

 son and assistant obviously marked out as successor to the 

 Directorship, father and son were settled together at the Mecca 

 of botany they had created, united by strong affection as well 

 as by a common work. 



The culminating point of Hooker's scientific work during 

 the decade is the Introductory Essay to the Flora of Tasmania, 

 * which in itself would have made Hooker famous,' writes 

 Professor Bower. 1 This was published in 1859, just before 

 the ' Origin of Species ' appeared. Six years earlier he had 

 published the corresponding Introductory Essay to the Flora 

 of New Zealand. The difference between the guiding con- 

 ceptions of these Essays, one in the middle, the other at the 

 end of his first great period of systematic work, is a measure 

 of the writer's advance in scientific theory, his long-standing 

 dissatisfaction with the older view of fixity of species finding 

 appeasement in the practical utility of the theory that species 

 originate in variation. 



He had long been the confidant of Darwin's views ; had 

 discussed and debated them with his old friend, providing 

 botanical information, offering criticisms, citing instances 

 and pointing out difficulties, suggesting his own solutions to 

 problems which had vexed him ever more insistently as he 

 more fully realised the fluidity of species, and the difficulty 

 of establishing ' specific types,' those abstract definitions, to 

 which individual specimens should be referred, being as hopeless 

 as the bed of Procrustes. On the main lines, at least, he was 

 approaching conviction. The new theory, privately discussed, 

 threw light on his own work if he was not yet, in the earlier 

 fifties, persuaded of all its details ; and he felt bound to avow 

 publicly the change of view brought about by his later in- 

 vestigations. But Darwin's views had not yet been concen- 

 trated and expressed as a whole. A summary of them was 

 given to the world in the * Origin.' The sledge-hammer effect 

 of this was still to be experienced. 



1 The present Professor of Botany at Glasgow. 



