CIIAT. XIII.] 
THE GALAPAGOS ISLANDS. 
275 
we know are of comparatively recent origin. Such are the 
Keeling or Cocos Islands in the Indian Ocean, situated about 
the same distance from Sumatra as the Galapagos from South 
America, but mere coral reefs, supporting abundance of cocoa- 
nut palms as their chief vegetation. These islands were visited 
by Mr. Darwin, and their natural history carefully examined. 
The only mammals are rats, brought by a wrecked vessel and 
said by Mr. Waterhouse to be common English rats, “but 
smaller and more brightly coloured so that we have here an 
illustration of how soon a difference of race is established under 
a constant and uniform difference of conditions. There are no 
true land-birds, but there are snipes and rails, both apparently 
common Malayan species. Beptiles are represented by one 
small lizard, but no account of this is given in the Zoology of the 
Voyage of the Beagle, and we may therefore conclude that it was 
an introduced species. Of insects, careful collecting only pro- 
duced thirteen species belonging to eight distinct orders. The 
only bettle was a small Elater, the Orthoptera were a Gryllus 
and a Blatta ; and there were two flies, two ants, and two small 
moths, one a Diopaea which swarms everywhere in the eastern 
tropics in grassy places. All these insects were no doubt brought 
either by winds, by floating timber (which reaches the islands 
abundantly), or by clinging to the feathers of aquatic or wading 
birds ; and we only require more time to introduce a greater 
variety of species, and a better soil and more varied vegetation, 
to enable them to live and multiply, in order to give these 
islands a fauna and flora equal to that of the Bermudas. Of 
wild plants there were only twenty species, belonging to nine- 
teen genera and to no less than sixteen natural families, while 
all w T ere common tropical shore plants. These islands are thus 
evidently stocked by waifs and strays brought by the winds and 
waves ; but their scanty vegetation is mainly due to unfavourable 
conditions — the barren coral rock and sand, of which they are 
wholly composed, together with exposure to sea-air, being 
suitable to a very limited number of species which soon mono- 
polise the surface. With more variety of soil and aspect a 
greater variety of plants would establish themselves, and these 
would favour the preservation and increase of more insects, 
T 2 
