PROCEEDINGS 



OF THE 



ROYAL PHYSICAL SOCIETY. 



SESSION CXIIL 



Wednesday, 2lst Novcmher 1883. — Eamsay H. Traquair, 

 Esq., M.D., President, in the Chair. 



Archibald Geikie, Esq., F.Pt.S., Director General of the 

 Geological Survey of Great Britain and Ireland, delivered 

 the following opening address : 



In his investigation of the history of the successive 

 revolutions through which the terrestrial areas of the earth's 

 surface have passed, the geologist places his chief reliance 

 upon the remains of plants and animals imbedded in the 

 rocks. The distribution of land and sea at different ancient 

 periods, the growtli and isolation or connection of continents 

 and islands, the position of long-vanished lakes and rivers, 

 the vicissitudes of climate in past time — these and other 

 geographical changes depend in large measure for their 

 evidence upon the testimony of organic remains. In the 

 reasoning by which the accepted conclusions in these matters 

 have been reached, there lies as a fundamental postulate the 

 assumption that the laws which now govern the biological 

 domain, have been operative from the beginning. While 

 fossil forms, on the Avhole, depart more and more from 

 living forms as we trace them into more ancient rocks, yet 

 were we transported into the Jurassic, or Carboniferous, or 



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