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.
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.