CHAR XIII THE GALAPAGOS ISLANDS 



287 



and to no less than sixteen natural families, while all were 

 common tropical shore plants.^ These islands are thus 

 evidently stocked by waifs and strays brought by the 

 winds and waves ; but their scanty vegetation is mainly 

 due to unfavourable conditions — the barren coral rock of 

 which they are wholly composed being suitable to very 

 few species, while the numerous crabs destroy the young 

 shoots unless in some way protected. With more variety 

 of soil and aspect a greater number of plants would 

 establish themselves, and these would favour the preserva- 

 tion and increase of more insects, birds, and other animals, 

 as we find to be the case in other small and remote 

 islands.^ 



1 Mr. H. 0. Forbes, who visited these islands in 1878, and Dr. Guppy 

 in 1889, have increased the number of wild plants to over forty, and 

 these belonged to twenty-six natural orders. 



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 tliere are forty-two species on the island, while the 

 remote period when it first received its vegetation may be indicated by the 

 fact that seven of the species are quite peculiar ; while of 102 species of 

 flowering plants sixty-two are peculiar, and there are eleven peculiar 

 genera. The same general character pervades the fauna. For so small 

 and remote 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 trans- 

 mission 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 fuller account 

 of the fauna of the island see the author's Geographical Distribution of 

 Animals, Vol. II. p. 49, and for the peculiar humming-birds, Natural 

 Selection and Tropical Nature, pp. 324 — 329. The account of the flora 



