DARWIN'S WANDER-YEARS 53 



species of native birds. A few snails complete the list. 

 Now most of these animals, though closely resembling 

 the fauna of Ecuador, the nearest mainland, are 

 specifically distinct ; they have varied (as we now know) 

 from their continental types owing to natural selection 

 tinder the new circumstances in which they have been 

 placed. But Darwin had not yet evolved that potent 

 key to the great riddle of organic existence. He saw 

 the problem, but not its solution. * Most of the organic 

 productions,' he says plainly, e are aboriginal creations, 

 found nowhere else ; there is even a difference between 

 the inhabitants of the different islands : yet all show a 

 marked relationship with those of America, though 

 separated from that continent by an open space of ocean, 

 between 500 and 600 miles in width. . . . Considering 

 the small size of these islands, we feel the more 

 astonished at the number of their aboriginal beings, 

 and at their confined range. Seeing every height 

 crowned with its crater, and the boundaries of most of 

 the lava-streams still distinct, we are led to believe that 

 within a period geologically recent the unbroken sea was 

 here spread out. Hence, both in space and time we 

 seem to be brought somewhat nearer to that great fact 

 that mystery of mysteries the first appearance of new 

 beings on this earth.' Among the most singular of 

 these zoological facts may be mentioned the existence 

 in the Galapagos archipelago of a genus of gigantic and 

 ugly lizard, the amblyrhyncus, unknown elsewhere, but 

 here assuming the forms of two species, the one marine 

 and the other terrestrial. In minuter points, the dif- 

 ferences of fauna and flora between the various islands 

 are simply astounding, so as to compel the idea that 

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