THE ' GENEEA PLANTAKUM ' 415 



predecessors of this monumental work were the ' Genera Plan- 

 tarum ' of Linnaeus (1737-1764), and that of Jussieu (1789), 

 to which may be added that of Endlicher (1836-1840). Both 

 Bentham and Hooker had felt the inconvenience of the want 

 of a Genera Plantarum founded on actual observation, to 

 replace the already antiquated ones of Endlicher and Meissner, 

 both of which, especially the latter, had been in great measure 

 mere compilations. In view of the gigantic nature of the 

 task they joined forces. But the authors specially wished 

 that the whole should be considered as the joint production 

 of them both. The characters embodied in the diagnoses 

 were drawn from the actual examination of specimens. Such 

 data could only be derived from a reliable and rich herbarium 

 such as Kew had then become. Thus the book is not in any 

 sense a compilation from the work of earlier writers, but it 

 contains a redrafting of the diagnoses on the basis of personal 

 observation. Probably into no work on Botany is there con- 

 densed so wide a field of personally recorded fact, expressed 

 in such precise terms. The authors were both mature ob- 

 servers. But while Hooker was at home in the forest and the 

 jungle, Bentham was rather a denizen of the herbarium. His 

 education as a conveyancing barrister gave point to his naturally 

 acute mind in the exact wording of diagnoses. The difficulty 

 of the task of Bentham and Hooker was greater than that 

 of their predecessors by reason of their wider knowledge and 

 the great increase in the number of recognised genera, conse- 

 quent upon the activity of collectors the world over. But their 

 ' Genera Plantarum ' was on that account a nearer approach 

 to finality. Hitherto its supremacy has not been challenged. 

 On the other hand it has formed the source from which diagnoses 

 have been liberally borrowed. 



In the arrangement of the contents the * Genera Plantarum ' 

 followed the prevalent custom of the time. This may puzzle 

 generations that come after. For they may say it is true that 

 Hooker took the first step towards a phyletic classification, by 

 adopting the view of mutability of species. He was the first 

 Systematic Botanist who did this. They may ask ' Why, after 

 making this important advance on the older methods, did he 



