THE HISTORY OF THE NORTH ATLANTIC 89 



bottoms of Norway and Scotland, on the top of Moel Tryfaen, 

 in Wales, and at similar great heights on the hills of America, 

 many of which can be traced back to early Tertiary times, and 

 can be found to have extended themselves over all the seas of 

 the northern hemisphere. They apply in like manner to the 

 ferns, the conifers, and the broad-leaved trees, many of which 

 we can now trace without specific change to the Eocene and 

 Cretaceous. They all show that the forms of living things are 

 more stable than the lands and seas in which they live. If we 

 were to adopt some of the modern ideas of evolution, we might 

 cut the Gordian knot by supposing that, as like causes produce 

 like effects, these types of life have originated more than once 

 in geological time, and need not be genetically connected with 

 each other. But while evolutionists repudiate such an appli- 

 cation of their doctrine, however natural and rational, it would 

 seem that nature still more strongly repudiates it, and will not 

 allow us to assume more than one origin for one species. 

 Thus the great question of geographical distribution remains 

 in all its force ; and, by still another of our geological paradoxes, 

 mountains become ephemeral things in comparison with the 

 delicate herbage which covers them, and seas are in their pre- 

 sent extent but of yesterday, when compared with the minute 

 and feeble organisms that creep on their sands or swim in their 

 waters. 



The question remains : Has the Atlantic achieved its des- 

 tiny and finished its course, or are there other changes in store 

 for it in the future? The earth's crust is now thicker and 

 stronger than ever before, and its great ribs of crushed and 

 folded rock are more firm and rigid than in any previous period. 

 The stupendous volcanic phenomena manifested in Mesozoic 

 and early Tertiary times along the borders of the Atlantic 

 have apparently died out. These facts are in so far guarantees 

 of permanence. On the other hand, it is known that move- 

 ments of elevation, along with local depression, are in progress 



