CHAP. XIII THE GALAPAGOS ISLANDS 287 



other animals, as we find to be the case in many small 

 and remote islands.^ 



Flora of the GalajKcgos. — The plants of these islands are 

 so much more numerous than the known animals, even 

 including the insects, they have been so carefully studied 

 by eminent botanists, and their relations throw so much 

 light on the past history of the group, that no apology is 

 needed for giving a brief outline of the peculiarities and 

 affinities of the flora. The statements we shall make on 

 this subject will be taken from the Memoir of Sir Joseph 

 Hooker in the Linnccan Transactions for 1851, founded 

 on Mr. Darwin's collections, and a later paper by N. J. 

 Andersson in the Liniia^a of 1861, embodying more recent 

 discoveries. 



^ Juan Fernandez is a good example of a small island whicii, 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. JSTo doult, 

 however, there are occasional storms, and there may have been intermediate 

 island:^ 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 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 in- 

 troduced 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 s.\\\hov'& Xatnral 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. 



