Presidential Address. 283 



many forms. Similar considerations apply to all those 

 Pliocene and Pleistocene mollnsks which are found in the 

 raised sea-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 angiosperms, many of which we can now follow with- 

 out even 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 G-ordian knot by supposing that, as like 

 causes produce like effects, these types of life have origin- 

 ated more than once in geological time, and need not be 

 genetically connected with each other. But while evolu- 

 tionists repudiate such an application of their doctrine, how- 

 ever 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 ques 

 tion 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 present 

 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 pre- 

 vious period. The stupendous volcanic phenomena mani- 

 fested in Mesozoic and early Tertiary times along the bor- 

 ders of the Atlantic have apparently died out. These facts 

 are in so far guarantees of permanence. On the other 

 hand, it is known that movements of elevation along with 

 local depression are in progress in the Arctic regions, and a 



