ADDRESS. 33 



basis of what is vaguely called evolution — cannot easily be isolated. I 

 would recommend to those biologists who discuss those questions to addict 

 themselves to the oyster. This familiar mollusk has successfully pur* 

 sued its course and has overcome all its enemies, from the flat-toothed 

 selachians of the Carboniferous to the oyster dredgers of the present 

 day, has varied almost indefinitely, and yet has continued to bo an oyster, 

 unless indeed it may at certain portions of its career have temporarily 

 assumed the disguise of a Gryphroa or an Exogyra. The history of such 

 an animal deserves to be traced with care, and much curious information 

 respecting it will be found in the report which I have cited. 



But in these respects the oyster is merely an example of many forms. 

 Similar considerations apply to all those Pliocene and Pleistocene mollusks 

 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 

 without 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. K we were to adopt some of ne modem 

 ideas of evolution we might cut the Gordian knot by supposing that, as 

 like causes can 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 application 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 geologi- 

 cal 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 oir swim in their waters. 



The question remains. Has the Atlantic achieved its destiny and 

 finished its course, or ui'e 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 mani- 

 fested 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 movemente of elevation 

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

 great weight of new sediment is being deposited along the borders of the 

 Atlantic, especially on its western side, and this is not improbably con- 

 nected with the earthquake shocks and slight movements of depression 

 which have occurred in North America. It is possible that these slow 



