GEOGRAPHICAL RANGE OF ANIMALS. 51 



tained, and it is also so well known how closely species 

 may be allied and yet differ in all the essential relations 

 which characterize species, that such loose investigations 

 are no longer justifiable. 



This close resemblance of animals and plants in distant 

 parts of the world is the most interesting subject of inves- 

 tigation with reference to the question of the unity of the 

 origin of animals; and to that of the influence of physical 

 agents upon organized beings in general. It appears to 

 me, that, as facts now point distinctly to an independent 

 origin of individuals of the same species in remote re- 

 gions, or of closely allied species representing one another 

 in distant parts of the world, one of the strongest argu- 

 ments in favour of the supposition, that physical agents 

 may have had a controlling influence in changing the 

 character of the organic world, is gone for ever. 



The narrowest limits within which certain Vertebrata 

 are circumscribed, are exemplified, among Mammalia, by 

 some large and remarkable species : the Orang-Outangs 

 upon the Simcla Islands; the Chimpanzee and the Gorilla 

 along the western coast of Africa ; several distinct species 

 of Ehinoceros about the Cape of Good Hope, and in Java 

 and Sumatra; the Pinchaque and the common Tapir in 

 South America, and the eastern Tapir in Sumatra; the 

 East Indian and the African Elephant, the Bactrian Camel 

 and the Dromedary, the Llamas, and the different kinds 

 of wild Bulls, wild Goats, and wild. Sheep, etc. ; among 

 Birds by the African Ostrich, the two American Rheas, 

 the Emeu (Dromceus) of New Holland, and the Casuary 

 (Casuarius galeatits) of the Indian Archipelago, and still 

 more by the different species of doves confined to parti- 

 cular islands in the Pacific Ocean ; among Reptiles, by the 

 Proteus of the cave of Adelsberg in Carinthia, and the 



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