400 CHARLES DARWIN 



ated any higher. The black sand felt much hotter, so that 

 even in thick boots it was quite disagreeable to walk over it. 



The natural history of these islands is eminently curious, 

 and well deserves attention. Most of the organic productions 

 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. The archipelago 

 is a little world within itself, or rather a satellite attached to 

 America, whence it has derived a few stray colonists, and 

 has received the general character of its indigenous produc- 

 tions. Considering the small size of the 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 ocean was here 

 spread out. Hence, both in space and time, we seem to be 

 brought somewhat near to that great fact that mystery of 

 mysteries the first appearance of new beings on this earth. 



Of terrestrial mammals, there is only jane,. which must be 

 considered as indigenous, namely, a mouse (Mus Galapa- 

 goensis), and this is confined, as far as I could: ascertain, to 

 Chatham Island, the most easterly island of the group. It 

 belongs, as I am informed by Mr. Waterhouse, to a division 

 of the family of mice characteristic of America. At James 

 Island, there is a rat sufficiently distinct from the common 

 kind to have been named and described by Mr. Waterhouse ; 

 but as it belongs to the old-world division of the family, and 

 as this island has been frequented by ships for the last hun- 

 dred and fifty years, I can hardly doubt that this rat is 

 merely a variety produced by the new and peculiar climate, 

 food, and soil, to which it has been subjected. Although no 

 one has a right to speculate without distinct facts, yet even 

 with respect to the Chatham Island mouse, it should be borne 

 in mind, that it may possibly be an American species im- 

 ported here ; for I have seen, in a most unfrequented part of 

 the Pampas, a native mouse living in the roof of a newly 



