io6 Permanence and Evolution. 



the complexity and indefiniteness of organic 

 composition. But though forms so allied as 

 those of species are not readily assignable to 

 an identical history in different parts of the 

 globe, it is not only conceivable, but is eminently 

 probable, that orders and classes have no nearer 

 link of relationship than is implied in their 

 community of organised substance and their 

 common history. . . . When we find the metal 

 tin in Prussia and Cornwall and nowhere else in 

 Europe, must we not conclude that in those two 

 countries, and nowhere else, a peculiar conjunc- 

 tion of conditions caused this peculiar evolution." 

 These remarks appear to me to be true and 

 irrefragable ; but if we accept such views, what 

 becomes of the argument for evolution from 

 geographical distribution, the argument from 

 ontogeny, or still more what becomes of the 

 profound assumption that resemblance between 

 organised beings necessarily or probably implies 

 community of descent. Lewes's combination of 



