somewhat like that of a starling, and that of the fourth
sub-group, Camarhynchus, is slightly parrot-shaped. Seeing this
gradation and diversity of structure in one small, intimately
related group of birds, one might really fancy that from an
original paucity of birds in this archipelago, one species had
been taken and modified for different ends. In a like manner
it might be fancied that a bird originally a buzzard, had been
induced here to undertake the office of the carrion-feeding
Polybori of the American continent.
Of waders and water-birds I was able to get only eleven
kinds, and of these only three (including a rail confined to
the damp summits of the islands) are new species. Considering
the wandering habits of the gulls, I was surprised to
find that the species inhabiting these islands is peculiar, but
allied to one from the southern parts of South America.
The far greater peculiarity of the land-birds, namely,
twenty-five out of twenty-six, being new species, or at least
new races, compared with the waders and web-footed birds, is
in accordance with the greater range which these latter
orders have in all parts of the world. We shall hereafter
see this law of aquatic forms, whether marine or fresh-water,
being less peculiar at any given point of the earth's
surface than the terrestrial forms of the same classes,
strikingly illustrated in the shells, and in a lesser degree in
the insects of this archipelago.
Two of the waders are rather smaller than the same species
brought from other places: the swallow is also smaller,
though it is doubtful whether or not it is distinct from its
analogue. The two owls, the two tyrant-catchers (Pyrocephalus)
and the dove, are also smaller than the analogous
but distinct species, to which they are most nearly related;
on the other hand, the gull is rather larger. The two owls,
the swallow, all three species of mocking-thrush, the dove
in its separate colours though not in its whole plumage, the
Totanus, and the gull, are likewise duskier coloured than
their analogous species; and in the case of the mocking-
thrush and Totanus, than any other species of the two genera.
With the exception of a wren with a fine yellow breast,
and of a tyrant-flycatcher with a scarlet tuft and breast, none
of the birds are brilliantly coloured, as might have been
expected in an equatorial district. Hence it would appear
probable, that the same causes which here make the immigrants
of some peculiar species smaller, make most of the
peculiar Galapageian species also smaller, as well as very
generally more dusky coloured. All the plants have a
wretched, weedy appearance, and I did not see one beautiful
flower. The insects, again, are small-sized and dull-coloured,
and, as Mr. Waterhouse informs me, there is nothing in their
general appearance which would have led him to imagine
that they had come from under the equator. [1] The birds,
plants, and insects have a desert character, and are not more
brilliantly coloured than those from southern Patagonia; we
may, therefore, conclude that the usual gaudy colouring of
the intertropical productions, is not related either to the
heat or light of those zones, but to some other cause, perhaps
to the conditions of existence being generally favourable
to life.
We will now turn to the order of reptiles, which gives
the most striking character to the zoology of these islands.
The species are not numerous, but the numbers of individuals
of each species are extraordinarily great. There is one
small lizard belonging to a South American genus, and two
species (and probably more) of the Amblyrhynchus - a genus
confined to the Galapagos Islands. There is one snake which
is numerous; it is identical, as I am informed by M. Bibron,
with the Psammophis Temminckii from Chile. [2] Of sea-
turtle I believe there are more than one species, and of
tortoises there are, as we shall presently show, two or three
species or races. Of toads and frogs there are none: I was
surprised at this, considering how well suited for them the
temperate and damp upper woods appeared to be. It recalled
to my mind the remark made by Bory St. Vincent, [3]
namely, that none of this family are found on any of the
volcanic islands in the great oceans. As far as I can ascertain
from various works, this seems to hold good throughout the
Pacific, and even in the large islands of the Sandwich
archipelago. Mauritius offers an apparent exception, where I
saw the Rana Mascariensis in abundance: this frog is said
now to inhabit the Seychelles, Madagascar, and Bourbon;
but on the other hand, Du Bois, in his voyage in 1669, states
that there were no reptiles in Bourbon except tortoises; and
the Officier du Roi asserts that before 1768 it had been
attempted, without success, to introduce frogs into Mauritius
- I presume for the purpose of eating: hence it may be well
doubted whether this frog is an aboriginal of these islands.
The absence of the frog family in the oceanic islands is the
more remarkable, when contrasted with the case of lizards,
which swarm on most of the smallest islands. May this difference
not be caused, by the greater facility with which the
eggs of lizards, protected by calcareous shells might be
transported through salt-water, than could the slimy spawn
of frogs?
I will first describe the habits of the tortoise (Testudo
nigra, formerly called Indica), which has been so frequently
alluded to. These animals are found, I believe, on all the
islands of the archipelago; certainly on the greater number.
They frequent in preference the high damp parts, but they
likewise live in the lower and arid districts.
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