416 HOOKEK'S POSITION AS BOTANIST 



maintain so nearly the grouping of orders and genera prevalent 

 before ? Should it not have been a logical necessity to attempt 

 some grouping more nearly in accordance with the probable lines 

 of evolution than that retained in the " Genera Plantarum " ? ' 

 Those who would urge these grounds for criticism long after 

 the event of publication should remember two essential facts. 

 The first is that the work was, as its name conveys, a work on 

 genera, not on the grouping of genera. Its value does not lie 

 in the order of the arrangement of the diagnoses, but in the 

 strictness of their definition. It deals with the cutting of the 

 gems, as apart from the plan of their setting. Gems these 

 diagnoses certainly are, and it is probable that they will not 

 be improved in the cutting for long enough to come. The 

 second essential point to be remembered by critics is the im- 

 mensity of the task of arriving at any phyletic grouping of 

 Angiosperms, and the uncertainty of the methods to be used. 

 Moreover the time was not ripe. For this work was planned in 

 1858, and the first part was published in 1862, within three 

 years of the production of the ' Origin of Species.' Even if the 

 authors had attempted a grouping according to some theory 

 of descent, they would have courted disaster. They knew 

 as well as any men of their time the complexity of the inter- 

 relations of Seed-Bearing Plants : the nicety of the distinc- 

 tions, and the vastness of the number of closely related forms. 

 To those who appreciate this, the wisdom of retaining the old 

 groupings is manifest. A quarter of a century later an attempt 

 was made by Engler and Prantl to attain a more satisfactory 

 arrangement (Die Natiirlichen Pflanzenfamilien. II. Embryo- 

 phy ta Siphonogama, 1 889) . They altered the sequence of orders 

 and genera, with results which are no doubt beneficial in the 

 main, though certainly not final. But the relatively brief 

 diagnoses there given are in no sense a substitute for those of 

 the * Genera Plantarum/ which remains, and will probably long 

 remain, the ultimate court of appeal. 



The ' Kew Index ' was produced under the personal supervision 

 of Sir Joseph Hooker. The expense of it was borne by Charles 

 Darwin, and by his family after his death. The scheme origin- 

 ated in the difficulty Darwin had foun,d in the accurate naming 



