CHAP. XXIII ARCTIC PLANTS IK NEW ZEALAND 



525 



is clear, therefore, that South Africa has received its Euro- 

 pean plants by the direct route through the Abyssinian 

 highlands and the lofty equatorial mountains, and mostly 

 at a distant period when the conditions for migration were 

 somewhat more favourable than they are now. The much 

 greater directness of the route from Northern Europe to 

 South Africa than to Australia; and the existence even 

 now of lofty mountains and extensive highlands for a large 

 portion of the distance, will explain (what Sir Josepli 

 Hooker notes as " a very curious fact ") why South Africa 

 has more very northern European genera than Australia, 

 while Australia has more identical species and a better rep- 

 resentation on the whole of the European flora — this being 

 clearly due to the large influx of species it has received 

 from the Antarctic Islands, in addition to those which have 

 entered it by way of Asia. The greater distance of South 

 Africa even now from any of these islands, and the much 

 deeper sea to the south of the African continent, than in 

 the case of Tasmania and New Zealand, indicating a 

 smaller recent extension southward, is all quite in harmony 

 with the facts of distribution of the northern flora above 

 referred to. 



Supposed Connection of South Africa and Australia.. — 

 There remains, however, the small amount of direct affinity 

 between the vegetation of South Africa and that of Austra- 

 lia, New Zealand, and Temperate South America, consisting 

 in all of fifteen genera, five of which are confined to 

 Australia and South Africa, while several natural orders 

 are better represented in these two countries than in any 

 other part of the world. This resemblance has been sup- 

 posed to imply some former land-connection of all the great 

 southern lands, but it appears to me that any such suppo- 

 sition is wholly unnecessary. The differences between the 

 faunas and floras of these countries are too great and too 

 radical to render it possible that any such connection 

 should have existed except at a very remote period. But 

 if we have to go back so far for an explanation, a much 

 simpler one presents itself, and one more in accordance 

 with what we have learnt of the general permanence of 

 deep oceans and the great changes that have taken place 



