330 



ISLAND LIFE 



PAET II 



clothed with vegetation. But in every case the series 

 of forms of life in these islands is scanty and im- 

 perfect as compared with far less favourable continental 

 areas, and no one of them presents such an assemblage of 

 animals or plants as we always find in an island which we 

 know has once formed part of a continent. 



It is still more important to note that none of these 

 oceanic archipelagoes present us with a single type which 

 we may suppose to have been preserved from Mesozoic 

 times ; and this fact, taken in connection with the volcanic 

 or coralline origin of all of them, powerfully enforces the 

 conclusion at which we have arrived in the earlier portion 

 of this volume, that during the whole period of geologic 

 time as indicated by the fossiliferous rocks, our continents 

 and oceans have, speaking broadly, been permanent features 

 of our earth's surface. For had it been otherwise — had sea 

 and land changed place repeatedly as was once supposed — 

 had our deepest oceans been the seat of great continents 

 while the site of our present continents was occupied by 

 an oceanic abyss — is it possible to imagine that no frag- 

 ments of such continents would remain in the present 

 oceans, bringing down to us some of their ancient forms of 

 life preserved with but little change ? The correlative 

 facts, that the islands of our great oceans are all volcanic 

 (or coralline built probably upon degraded volcanic islands 

 or extinct submarine volcanoes), and that their productions 

 are all more or less clearly related to the existing inhabit- 

 ants of the nearest continents, are hardly consistent with 

 any other theory than the permanence of our oceanic and 

 continental areas. 



We may here refer to the one apparent exception, which, 

 however, lends additional force to the argument. New 

 Zealand is sometimes classed as an oceanic island, but it is 

 not so really ; and we shall discuss its peculiarities and 

 probable origin further on. 



