Hence it would appear probable that the same
causes which here make the immigrants of some 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. (17/1. The progress of research has shown that some of
these birds, which were then thought to be confined to the islands,
occur on the American continent. The eminent ornithologist, Mr.
Sclater, informs me that this is the case with the Strix
punctatissima and Pyrocephalus nanus; and probably with the Otus
galapagoensis and Zenaida galapagoensis: so that the number of
endemic birds is reduced to twenty-three, or probably to
twenty-one. Mr. Sclater thinks that one or two of these endemic
forms should be ranked rather as varieties than species, which
always seemed to me probable.) 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.
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