AS PHILOSOPHICAL BIOLOGIST 321 



Plant-Geographer. He found that the Antarctic, like the Arctic 

 Flora, is very uniform round the Globe. The same species in 

 many cases occur on every island, though thousands of miles of 

 ocean may intervene. Many of these species reappear on the 

 mountains of Southern Chili, Australia, Tasmania, and New- 

 Zealand. The Southern Temperate Floras, on the other hand, 

 of South America, South Africa, Australia, and New Zealand 

 differ more among themselves than do the Floras of Europe, 

 Northern Asia, and North America. To explain these facts he 

 suggested the probable former existence, during a warmer period 

 than the present, of a centre of creation of new species in the 

 Southern Ocean, in the form of either a continent or an archipelago, 

 from which the Antarctic Flora radiated. This hypothesis has 

 since been held open to doubt. But the fact that it was suggested 

 shows the broad view which he was prepared to take of the 

 problem before him. His method was essentially that which is 

 now styled " Ecological." Many hold this to be a new phase of 

 botanical enquiry, introduced by Professor Warming in 1895. 

 No one will deny the value of the increased precision which he 

 then brought into such studies. But in point of fact it was 

 Ecology on the grand scale that Sir Joseph Hooker practised in 

 the Antarctic in 1840. Moreover it was pursued, not in regions 

 of old civilisation, but in lands where Nature held her sway un- 

 touched by the hand of man. 



This Essay on the Flora of the Antarctic was the prototype 

 of the great series. Sir Joseph examined the Arctic Flora from 

 similar points of view. He explained the circumpolar uniformity 

 which it shows, and the prevalence of Scandinavian types, to- 

 gether with the peculiarly limited nature of the Flora of the 

 southward peninsula of Greenland. He extended his enquiries 

 to oceanic islands. He pointed out that the conditions which 

 dictated circumpolar distribution are absent from them ; but 

 that other conditions exist in them which account for the strange 

 features which their vegetation shows. He extended the appli- 

 cation of such methods to the Himalaya and to Central Asia. 

 He joined with Asa Gray in like enquiries in North America. 

 The latter had already given a scientific explanation of the 

 surprising fact that the plants of the Eastern States resemble 

 o. B. 21 



