[107] "The late Sir C. Wyville Thomson was of opinion that the 'red earth' which largely forms the soil of Bermuda had an organic origin, as well as the 'red clay' which the Challenger discovered in all the greater depths of the ocean basins. He regarded the red earth and red clay as an ash left behind after the gradual removal of the lime by water charged with carbonic acid. This ash he regarded as a constituent part of the shells of Foraminifera, skeletons of Corals, and Molluscs, [vide Voyage of the Challenger, Atlantic, Vol. I. p. 316]. This theory does not seem to be in any way tenable. Analysis of carefully selected shells of Foraminifera, Heteropods, and Pteropods, did not show the slightest trace of alumina, and none has as yet been discovered in coral skeletons. It is most probable that a large part of the clayey matter found in red clay and the red earth of Bermuda is derived from the disintegration of pumice, which is continually found floating on the surface of the sea. [See Murray, "On the Distribution of Volcanic Débris Over the Floor of the Ocean;" Proc. Roy. Soc. Edin. Vol. IX. pp. 247-261. 1876-1877.] The naturalists of the Challenger found it among the floating masses of gulf weed, and it is frequently picked up on the reefs of Bermuda and other coral islands. The red earth contains a good many fragments of magnetite, augite, felspar, and glassy fragments, and when a large quantity of the rock of Bermuda is dissolved away with acid, a small number of fragments are also met with. These mineral particles most probably came originally from the pumice which had been cast up on the island for long ages (for it is known that these minerals are present in pumice), although possibly some of them may have come from the volcanic rock, which is believed to form the nucleus of the island." The Voyage of H.M.S. Challenger, Narrative of the Cruise, Vol. I. 1885, pp. 141-142.
[108] Four bats occur rarely, two being N. American, and two West Indian Species. The Bermuda Islands, by Angelo Heilprin, Philadelphia, 1889.
[109] Fourteen species of Spiders were collected by Prof. A. Heilprin, all American or cosmopolitan species except one, Lycosa atlantica, which Dr. Marx of Washington describes as new and as peculiar to the islands. (Heilprin's The Bermudas, p. 93.)
[110] Mr. Theo. D. A. Cockerell informs me that there are two slugs in Bermuda of which specimens exist in the British Museum,—Amalia gagates Drap. common in Europe, and Agriolimax campestris of the United States. Both may therefore have been introduced by human agency. Also Vaginulus Morelete var. schivelyæ which seems to be a variety of a Mexican species; perhaps imported.
[111] "Notes on the Vegetation of Bermuda," by H. N. Moseley. (Journal of the Linnean Society, Vol. XIV., Botany, p. 317.)
[112] Gigantic Land Tortoises Living and Extinct in the Collection of the British Museum. By A. C. L. G. Günther, F.R.S. 1877.
[113] The following list of the beetles yet known from the Galapagos shows their scanty proportions and accidental character; the forty species belonging to thirty-three genera and eighteen families. It is taken from Mr. Waterhouse's enumeration in the Proceedings of the Zoological Society for 1877 (p. 81), with a few additions collected by the U. S. Fish Commission Steamer Albatross, and published by the U. S. National Museum in 1889.
| Carabidæ. Feronia calathoides. ,, insularis. ,, galapagoensis. Amblygnathus obscuricornis. Solenophorus galapagoensis. Notaphus galapagoensis. Dytiscidæ. Eunectes occidentalis. Acilius incisus. Copelatus galapagoensis. Palpicornes. Tropisternus lateralis. Philhydrus sp. Staphylinidæ. Creophilus villosus. Necrophaga. Acribis serrativentris. Phalacrus darwinii. Dermestes vulpinus. Malacoderms. Ablechrus darwinii. Corynetes rufipes. Bostrichus unciniatus. Tetrapriocerca sp. Lamellicornes. Copris lugubris. Oryctes galapagoensis. |
Elateridæ. Physorhinus galapagoensis Heteromera. Allecula n. s. Stomion helopoides. ,, lævigatum. Ammophorus obscurus. ,, cooksoni. ,, bifoveatus. Pedonœces galapagoensis. ,, pubescens. Phaleria manicata. Curculionidæ. Otiorhynchus cuneiformis. Anchonus galapagoensis. Longicornia. Mallodou sp. Eburia amabilis. Anthribidæ. Ormiscus variegatus. Phytophaga. Diabrotica limbata. Docema galapagoensis. Longitarsus lunatus. Securipalpes. Scymuns galapagoensis. |
[114] Mr. H. O. Forbes, who visited these islands in 1878, increased the number of wild plants to thirty-six, and these belonged to twenty-six natural orders.
[115] Juan Fernandez is a good example of a small island which, with time and favourable conditions, has acquired a tolerably rich and highly peculiar flora and fauna. It is situated in 34° S. Lat., 400 miles from the coast of Chile, and so far as facilities for the transport of living organisms are concerned is by no means in a favourable position, for the ocean-currents come from the south-west in a direction where there is no land but the Antarctic continent, and the prevalent winds are also westerly. No doubt, however, there are occasional storms, and there may have been intermediate islands, but its chief advantages are its antiquity, its varied surface, and its favourable soil and climate, offering many chances for the preservation and increase of whatever plants and animals have chanced to reach it. The island consists of basalt, greenstone, and other ancient rocks, and though only about twelve miles long its mountains are three thousand feet high. Enjoying a moist and temperate climate it is especially adapted to the growth of ferns, which are very abundant; and as the spores of these plants are as fine as dust, and very easily carried for enormous distances by winds, it is not surprising that there are nearly fifty species on the island, while the remote period when it first received its vegetation may be indicated by the fact that nearly half the species are quite peculiar; while of 102 species of flowering plants seventy are peculiar, and there are ten peculiar genera. The same general character pervades the fauna. For so small an island it is rich, containing four true land-birds, about fifty species of insects, and twenty of land-shells. Almost all these belong to South American genera, and a large proportion are South American species; but several of the insects, half the birds, and the whole of the land-shells are peculiar. This seems to indicate that the means of transmission were formerly greater than they are now, and that in the case of land-shells none have been introduced for so long a period that all have become modified into distinct forms, or have been preserved on the island while they have become extinct on the continent. For a detailed examination of the causes which have led to the modification of the humming birds of Juan Fernandez see the chapter on Humming Birds in the author's Natural Selection and Tropical Nature, p. 324; while a general account of the fauna of the island is given in his Geographical Distribution of Animals, Vol. II. p. 49.