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 been subjected.