212 Darwin, and after Darwin. 



Old World cousins in form and habits ; but differ 

 from them in dentition and other such minor points. 

 Now, the question is, Why should all the 100 

 species have been separately created on one side 

 of the Atlantic with one pattern of dentition, and 

 all the 70 species on the other side with another 

 pattern ? What has the Atlantic Ocean got to do 

 with any " archetypal plan " of rats' teeth ? 



Or again, to recur to Australia, why should all 

 the mammalian forms of life be restricted to the 

 one group of Marsupials, when we know that not 

 only the Rodents, such as the rabbit, but all other 

 orders of mammals, -would thrive there equally well. 

 And similarly, of course, in countless other instances. 

 Everywhere we meet with this same correlation 

 between areas of distribution and affinities of classifi- 

 cation. 



Now, it is at once manifest how completely this 

 general fact harmonizes with the theory of evolution. 

 If the 400 species of humming-birds, for instance, are all 

 modified descendants of common ancestors, and if none 

 of their constituent individuals have ever been large 

 enough to make their way across the oceans which 

 practically isolate their territory from all other tropi- 

 cal and sub-tropical regions of the globe, then we can 

 understand why it is that all the 400 species occupy 

 the same continent. But on the special-creation 

 theory we can see no reason why the 400 species 

 should all have been deposited in America. And, as 

 already observed, we must remember that this corre- 

 lation between a geographically restricted habitat 

 and the zoological or botanical affinities of its inhabi- 

 tants, is repeated over and over and over again in the 



