400 
GEOGEAPHICAL DISTEIBUTION. 
Chap. XII. 
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 explained. 
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 
betw^een 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, &c., 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 considering 
the physical conditions of a country as the most im¬ 
portant for its inhabitants; whereas it cannot, I think, 
be disputed that the nature of the other inhabitants, 
with which each has to compete, is as least as impor¬ 
tant, and generally a far more important element of 
success. Now if we look to those inhabitants of the 
Galapagos Archipelago which are found in other parts 
of the world (laying on one side for the moment the 
