EVIDENCES OF EVOLUTION. 127 



has shown that the same law holds good with sea- 

 shells, but from the wide distribution of most mol- 

 lusca it is not well displayed by them. Other cases 

 could be added, as the relation between the extinct 

 and living brackish-water shells of the Aralo-Caspian 

 sea." 1 



It is no explanation of the facts of geographical 

 distribution to say that species are specially adapted 

 to the habitats in which they are found ; that South 

 America, for instance, is especially fitted for eden- 

 tates, and Australia for marsupials. " That it is not 

 the suitability of organisms to the areas which they 

 inhabit that has determined their creation upon 

 these areas, is," says Romanes, " conclusively proved 

 by the effects of the artificial transportation of 

 species by man. For in such cases it frequently 

 happens, that the imported species thrives quite as 

 well in its new as in its old home, and indeed often 

 supplants the native species. As the Maoris say : 

 'As the white man's rat has driven away the native 

 rat, so the European fly has driven away our fly, so 

 the clover kills our fern, and so will the Maori him- 

 self disappear before the white man.' "* 



The Demonstrative Evidence of Evolution. 



We come now to what Huxley designates spe- 

 cifically "the demonstrative evidence of Evolution," 

 the evidence based on the lineal succession of 

 several carefully-studied types, and above all, the 



1% 'The Origin of Species," vol. II. p. 121. 



2 " Scientific Evidence of Organic Evolution,'' chap. iv. 



