GEOGRAPHICAL DISTRIBUTION 359 



is so enormously remote, that the fact becomes an 

 anomaly. But this difficulty almost disappears on the 

 view that both New Zealand, South America, and 

 other southern lands were long ago partially stocked 

 from a nearly intermediate though distant point, namely 

 from the antarctic islands, when they were clothed with 

 vegetation, before the commencement of the 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, and is at 

 present inexplicable : but this affinity is confined to 

 the plants, and will, I do not doubt, be some day ex- 

 plained. 



The law which causes the inhabitants of an archi- 

 pelago, though specifically distinct, to be closely allied 

 to those of the nearest continent, we sometimes see 

 displayed on a small scale, yet in a most interesting 

 manner, within the limits of the same archipelago. 

 Thus the several islands of the Galapagos Archipelago 

 are tenanted, as I have elsewhere shown, in a quite 

 marvellous manner, by very closely related species ; 

 so that the inhabitants of each separate island, though 

 mostly distinct, are related in an incomparably closer 

 degree to each other than to the inhabitants of any 

 other part of the world. And this is just what might 

 have been expected on my view, for the islands are 

 situated so near each other that they would almost 

 certainly receive immigrants from the same original 

 source, or from each other. But this dissimilarity 

 between the endemic inhabitants of the islands may 

 be used as an argument against my views ; for it may 

 be asked, how has it happened in the several islands 

 situated within sight of each other, having the same 

 geological nature, the same height, climate, etc., that 

 many of the immigrants should have been differently 

 modified, though only in a small degree. This long 

 appeared to me a great difficulty : but it arises in 

 chief part from the deeply -seated error of consider- 

 ing the physical conditions of a country as the most 



