42 DISTRIBUTION OF SOUTHERN FAUNAS, 



It is evident that in any large district, like Australasia, there is 

 no reason to suppose that the ancestors of the animals and plants 

 now inhabiting it all came from the same direction or at the same 

 time : consequently the first step to take is to try to separate the 

 fauna and flora into groups which find their nearest relations in 

 different directions. Thus in Australasia we have — 



1. An Australasian fauna and flora which have no near 

 relatives now living. 



2. A northern fauna and flora related to the Oriental fauna 

 and flora of the present day. 



3. A south-tropical or sub-tropical fauna and flora whose nearest 

 relations at present are either in S. Africa or in S. America north 

 of 40° 8. That the differences between these countries are far 

 greater than their resemblances does not do away with the 

 existence of these resemblances, but rather accentuates them. 

 They are vestigial remains with all the importance that vestigial 

 remains always possess. 



4. A south-temperate or cold-temperate fauna and flora, with 

 relations to plants and animals in Patagonia or Chili and the 

 Antarctic Islands. This is usually called the Antarctic element. 



Judging by the relative closeness of the relationship of these 

 different fauuistic elements to their foreign connections, we must 

 conclude that the first and third are much older inhabitants of 

 Australasia than the second and fourth. . The second element, 

 which is best developed in north-eastern Australia, presents no 

 difficulty and everyone is agreed as to its origin. The fourth 

 element, which is better developed in New Zealand than in any 

 other part of Australasia, consists of marine animals with a few 

 migratory fresh-water fishes and possibly some land mollusca and 

 worms; and there is a general consensus of opinion that these 

 spread by means of a greater development of land in the Antarctic 

 region. This may have been as late as the Older Pliocene, but 

 not later, as considerable changes have taken place in the animals 

 since it occurred. Also, as pointed out in the first paragraphs of 

 this paper, this land could not have been continuous between S. 



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