XVII 
NATURAL HISTORY 
403 
became very oppressive. On two days the thermometer within 
the tent stood for some hours at 93 0 ; but in the open air, in 
the wind and sun, at only 85°. The sand was extremely hot ; 
the thermometer placed in some of a brown colour immediately 
rose to 1 37 0 , and how much above that it would have risen I 
do not know, for it was not graduated 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 productions. 
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 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 one which must be 
considered as indigenous, namely a mouse (Mus Galapagoensis), 
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 hundred 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 
