EXCURSIONS OF AN EVOLUTIONIST 



ard ; and in striking contrast with all this gen- 

 eral extreme paucity of animal forms, there are 

 at least fifty-five species of birds. Now these 

 insects, mollusks, reptiles, and birds are like the 

 insects, mollusks, reptiles, and birds of the west- 

 ern coast of South America, and not like the 

 corresponding animals in other parts of the 

 world. But this is not all ; for the Galapagos 

 animals, while very like the animals of Ecuador, 

 Peru, and Chili, are not quite like them. While 

 the families are identical, the differences are 

 always at least specific, sometimes generic, in 

 value. Precisely the same sort of relationship 

 is sustained by the Galapagos flora toward the 

 flora of the mainland. And, to crown all, the 

 differences between forms that are generic when 

 the archipelago as a whole is compared with the 

 continent sink into specific differences when the 

 several islands of the archipelago are compared 

 with one another. Such a group of facts as these 

 leads irresistibly to the conclusion that the speci- 

 fic forms of plants and animals have been origi- 

 nated, not by " special creations," but by " de- 

 scent with modifications." If species have been 

 separately created, there is of course no reason 

 why the population of such an archipelago should 

 be strictly limited to such organisms as can fly or 

 get floated across the water ; nor is there any 

 reason why these organisms should resemble 

 those of the nearest mainland rather than those 



