3C2 RELATIONS OF THE INHABITANTS OF Chap. XII. 



ten species, in :i ])ox pierced with holes, and immersed it for a 

 fortnight in the sea. Out of the hundred shells, twenty-seven 

 recovered. The presence of an ojierculum seems to have been 

 of importance, as out of twelve sj^ecimcns of Cydostoma cle- 

 gans, which is thus furnished, eleven revived. It is remarkable, 

 seeing how well with me the Helix pomatia resisted the salt- 

 water, that not one of fifty-four specimens, l^elonging to four 

 species of Helix tried by Aueapitaine, recovered. It is, how- 

 ever, not at all probable that land-shells have often been thus 

 transported ; the feet of birds is a more probable method. 



On the Relations of the Inhabitants of Islaiids to those oftJie 

 nearest Main-land. 



The most striking and important fact for us is the affinity 

 of the species which inhabit islands to those of the nearest 

 main-land, without being actually the same. Numerous in- 

 stances could be given. The Galapagos Archipelago, situated 

 under the equator, lies at the distance of between 500 and GOO 

 miles from the shores of Soutli America. Here almost every 

 jiroduct of the land and the water l)ears the unmistakable 

 stamp of the American Continent. There are twenty-six land- 

 birds, and twenty-one, or, perhaps, twenty-three, of these arc 

 )"anked as distinct species, and are supposed to have been 

 created here ; yet the close affinity of most of these birds to 

 American species in every character, in their habits, gestures, 

 and tones of A^oice, was manifest. So it is with the other ani- 

 mals, and with a large proportion of the plants, as shown by 

 Dr. Hooker in his admirable Flora of this archipelago. The 

 naturalist, looking at the inhabitants of these volcanic islands 

 in the Pacific, distant several hundred miles from the continent, 

 yet feels that he is standing on American land. Why should 

 this be so ? why should the species which are supposed to 

 have been created in the Galapagos Archipelago, and nowhere 

 else, bear so plain a stamp of affinity to those created in Amer- 

 ica ? There is nothing in the conditions of life, in the geologi- 

 cal nature of the islands, in their height or climate, or in the 

 proportions in which the several classes are associated to- 

 gether, which closely resembles the conditions of the South 

 American coast : in fact, there is a considerable dissimilarity 

 in all the foregoing respects. On the other hand, there is a 

 considerable degree of resemblance in the volcanic nature of 

 the soil, in the climate, height, and size of the islands, be- 



