, height, and size of the
islands, between the Galapagos and Cape de Verde Archipelagoes; but
what an entire and absolute difference in their inhabitants! The
inhabitants of the Cape de Verde Islands are related to those of
Africa, like those of the Galapagos to America. Facts such as these
admit of no sort of explanation on the ordinary view of independent
creation; whereas on the view here maintained, it is obvious that
the Galapagos Islands would be likely to receive colonists from
America, and the Cape de Verde Islands from Africa; such colonists
would be liable to modification--the principle of inheritance still
betraying their original birthplace[22].

[22] _origin of species_, pp. 353-4.

The following is a synopsis of the fauna and flora of this archipelago,
so far as at present known. The only terrestrial vertebrates are two
peculiar species of land-tortoise, and one extinct species; five species
of lizards, all peculiar--two of them so much so as to constitute a
peculiar genus;--and two species of snakes, both closely allied to South
American forms. Of birds there are 57 species, of which no less than 38
are peculiar; and all the non-peculiar species, except one, belong to
aquatic tribes. The true land birds are represented by 31 species, of
which all, except one, are peculiar; while more than half of them go to
constitute peculiar genera. Moreover, while they are all unquestionably
allied to South American forms, they present a beautiful series of
gradations, "from perfect identity with the continental species, to
genera so distinct that it is difficult to determine with what forms
they are most nearly allied; and it is interesting to note that this
diversity bears a distinct relation to the probabilities of, and
facilities for, migration to the islands. The excessively abundant
rice-bird, which breeds in Canada, and swarms over the whole United
States, migrating to the West Indies and South America, visiting the
distant Bermudas almost every year, and extending its range as far as
Paraquay, is the only species of land-bird which remains completely
unchanged in the Galapagos; and we may therefore conclude that some
stragglers of the migrating host reach the islands sufficiently often to
keep up the purity of the breed[23]." Again, of the thirty peculiar
land-birds, it is observable that the more they differ from any other
species or genera on the South Am