350 INHABITANTS OF OCEANIC ISLANDS. Cuai-. XII. 



the barren isluiul of Ascension aboriginally possessed less than 

 half a dozen lowering plants ; yet many have now become 

 naturalized on it, as they have on New Zealand and on every 

 other oceanic island Avhich can be named. In St. Helena there 

 is reason to believe that the naturalized plants and animals 

 have nearly or quite exterminated many native productions. 

 He who admits the doctrine of the creation of each separate 

 species, will have to admit that a sufficient number of the best 

 adapted plants and animals were not created for oceanic 

 islands ; for man has unintentionally stocked them far more 

 fully and perfectly than did Nature. 



Although in oceanic islands the species are few in number, 

 the proportion of endemic kinds (i. e., those found nowhere 

 else in the Avorld) is often extremely large. If Ave compare, 

 for instance, the number of endemic land-shells in Madeira, or 

 of endemic birds in the Galapagos Archipelago, Avith the num- 

 ber found on any continent, and then compare the area of the 

 island Avith that of the continent, Ave shall see that this is true. 

 This fact might have been theoretically expected, for, as al- 

 ready explained, species occasionally arriving after long inter- 

 A'als of time in a ncAV and isolated district, and having to com- 

 pete AA'ith ncAV associates, Avould be eminently liable to modifi- 

 cation, and Avould often produce groups of modified descend- 

 ants. But it by no means folloAvs that, because in an island 

 nearly all the species of one class are peculiar, those of an- 

 other class, or of another section of the same class, are pecu- 

 liar ; and this difference seems to depend partly on the species 

 Avhich are not modified having immigrated in a body, so that 

 their mutual relations haA^e not been much disturbed; and 

 partly on the frequent arrival of immodified immigrants from 

 the mother-country, Avith Avhich the insular forms have inter- 

 crossed. It should be borne in mind that the offspring of such 

 crosses AA'ould almost certainly gain in vigor ; so that even an 

 occasional cross AA'ould produce more effect than might have 

 been anticipated. I Avill give a fcAV illustrations of the forego- 

 ing remarks : in the Galapagos Islands there are 20 land-birds; 

 of these, 21 (or perhaps 23) are peculiar, AA'hereas of the 11 

 marine birds only 2 are peculiar ; and it is obvious that marine 

 lairds could arrive at these islands much more easily and fre- 

 quently than land-birds. Bermuda, on the other hand, Avhich 

 lies at about the same distance from North America as the 

 Galapagos Islands do from South America, and Avhich has a 

 A'cry peculiar soil, does not possess a single endemic land-bird ; 



