Presidential Address. 26*7 



Atlantic, and around the Pacific respectively, there seems 

 to be less parallelism between the deposits and forms of life 

 of the two oceans as compared with each other, and less 

 correspondence in forms of life, especially in modern times. 

 Still in the earlier geological ages, as might have been anti. 

 cipated from the imperfect development of the continents, 

 the same forms of life characterise the whole ocean from 

 Australia to Arctic America, and indicate a grand unity of 

 Pacific and Atlantic life not equalled in later times, * and 

 which speaks of contemporaneity rather than of what has 

 been termed homotaxis. 



We may pause here for a moment to notice some of the 

 effects of Atlantic growth on modern geography. It has 

 given us rugged and broken shores composed of old rocks 

 in the north, and newer formations and softer features to- 

 ward the south. It has given us marginal mountain ridges 

 and internal plateaus on both sides of the sea. It has pro- 

 duced certain curious and by no means accidental corres- 

 pondences of the eastern and western sides. Thus the solid 

 basis on which the British Islands stand may be compared 

 with Newfoundland and Labrador, the English Channel 

 with the Gulf of St. Lawrence, the Bay of Biscay with the 

 Bay of Maine, Spain with the projection of the American 

 land at Cape Hatteras, the Mediterranean with the Gulf of 

 Mexico. The special conditions of deposition and plication 

 necessary to these results, and their bearing on the char- 

 acter and productions of the Atlantic basin would require 

 a volume for their detailed elucidation. 



Thus far our discussion has been limited almost entirely 

 to physical causes and effects. If we now turn to the life 

 history of the Atlantic, we are met at the threshold with 

 the question of climate, not as a thing fixed and immutable, 

 but as changing from age to age in harmony with geogra- 

 phical mutations, and ju'oducing long cosmic summers and 

 winters of alternate warmth and refrigeration. 



1 Daintree and Etheridge, ' Queensland Geology,' Journal Geolo- 

 gical Society, August 1S72; R. Etheridge, Junior, ' Australian Fos- 

 sils,' Trans. Phys. Soc, Edin. 1880. 



