242 Darwin, and after Darwin. 



plain why some of the Alpine species are unique, 

 though closely allied to Arctic forms. 



Next we saw that, although living things are always 

 adapted to the climates under which they live (since 

 otherwise they could not live there at all), it is equally 

 true that, as a rule, besides the area on which they do 

 live, there are many other areas in different parts of 

 the globe where they might have lived equally well. 

 Consequently we must conclude that, if all species 

 were separately created, many species were severally 

 created on only one among a number of areas where 

 they might equally well have thrived. Now, although 

 this conclusion in itself may not seem opposed to the 

 theory of special creation, a most serious difficulty is 

 raised when it is taken in connexion with another fact 

 of an equally general kind. This is, that on every 

 biological region we encounter chains of allied species 

 constituting allied genera, families, and so on ; while 

 we scarcely ever meet with allied species in different 

 biological regions, notwithstanding that their climates 

 may be similar, and, consequently, just as well suited 

 to maintain some of the allied species. Hence we 

 must further conclude, if all species were separately 

 created, that in the work of creation some unac- 

 countable regard was paid to making areas of dis- 

 tribution correspond to degrees of structural affinity. 

 A great many species of the rat genus were created 

 in the Old World, and a great many species of 

 another, though allied, genus were created in the 

 New World : yet no reason can be assigned why no 

 one species of the Old World series should not just 

 as well have been deposited in the New World, and 

 vice versa. On the other hand, the theory of evolution 



