chap, xiii.] THE AUSTRALIAN REGION. 447 



Sandwich Islands, by the peculiar plants which are found on 

 their mountains. The peak of Teneriffe produces no Alpine 

 plants of European type, and this has been considered to prove 

 that it has been always isolated ; whereas the occurrence of North 

 Temperate forms on the mountains of Java, accords with other evi- 

 dence of this island having once formed part of the Asiatic con- 

 tinent. Now on the higher summits of the Sandwich Islands, 

 nearly 30 genera of Arctic and North Temperate flowering plants 

 have been found. Many of these occur also in the South Temperate 

 zone, in Australia or New Zealand ; but there are others which 

 seem plainly to point to a former connection with some North 

 Temperate land, probably California, as a number of islets are 

 scattered in the ocean between the two countries. The most 

 interesting genera are the following : — Silene, which is wholly 

 North Temperate, except that it occurs in S. Africa ; Vicia, 

 also North Temperate, and in South Temperate America; 

 Fragaria, with a similar distribution; Aster, widely spread 

 in America, otherwise North Temperate only ; Vaccinium, 

 wholly confined to the northern hemisphere, in cold and 

 temperate climates. None of these are found in Australia or 

 New Zealand ; and their presence in the Sandwich Islands 

 seems clearly to indicate a former approximation to North 

 Temperate America, although the absence of any American 

 forms of vertebrata renders it certain that no actual land con- 

 nection ever took place. 



Recent soundings have shown, that the Sandwich Islands 

 rise from a sea which is 3,000 fathoms or 18,000 feet deep ; 

 while there is a depth of at least 2,000 fathoms all across to 

 California on one side, and to Japan on the other. Between 

 the Fiji Islands, New Caledonia, the Solomon Islands, and 

 Australia, the depth is about 1,300 fathoms, and between Sydney 

 and New Zealand 2,600 fathoms ; showing, in every case, a 

 general accordance between the depth of sea and the approxi- 

 mation of the several faunas. In a few more years, when it is 

 to be hoped we shall know the contour of the sea-bottom better 

 than that of the continents, we shall be able to arrive at more 

 definite and trustworthy conclusions as to the probable changes 



