Page - 441 - in The Origin of Species

INHABITANTS OF ISLANDS 441 est large island. The exceptions are few, and most of them can be explained. Thus although Kerguelen Land stands nearer to Africa than to America, the plants are related, and that very closely, as we know from Dr. Hooker's account, to those of America: but on the view that this island has been mainly stocked by seeds brought with earth and stones on icebergs, drifted by the prevailing currents, this anomaly disappears. New Zealand in its endemic pianos is much more closely related to Australia, the nearest mainland, than to any other region: and this is what might have been ex- pected ; but it is also plainly related to South America, which, although the next nearest continent, is so enormously remote, that the fact becomes an anomaly. But this difficulty par- tially disappears on the view that New Zealand. South America, and the other southern lands have been stocked in part from a nearly intermediate though distant point, namely from the antarctic islands, when they were clothed with vege- tation, during a warmer tertiary period, before the com- mencement of the last Glacial period. The affinity, which though feeble, I am assured by Dr. Hooker is real, between the flora of the south-western corner of Australia and of the Cape of Good Hope, is a far more remarkable case : but this affinity is confined to the plants, and will, no doubt, some day be explained. The same law which has determined the relationship be- tween the inhabitants of islands and the nearest mainland, is sometimes displayed on a small scale, but in a most interest- ing manner, within the limits of the same archipelago. Thus each separate island of the Galapagos Archipelago is ten- anted, and the fact is a marvellous one, by many distinct species ; but these species are related to each other in a very much closer manner than to the inhabitants of the .American continent, or of any other quarter of the world. This is what might have been expected, for islands situated so near to each other would almost necessarily receive immigrants from the same original source, and from each other. But how is it that many of the immigrants have been differently modified, though only in a small degree, in islands situated within sight of each other, having the same geological na- ture, the same height, climate, &c. ? This long aiiiK'arcd to