ADDRESfi. 21 



blished by the observations of the Challengery and so well expounded by 

 Wallace and Homsley,' between the florns of oceanic islands and the con- 

 tinents, establish this conclusively. Thus the Bermudas, altogether recent 

 islands, have been stocked by the agency chiefly of the ocean currents 

 and of birds, with nearly 150 species of continental plants, and the facts 

 collected by Hemsley as to the present facilities of transmission, along with 

 the evidence afforded by older oceanic islands which have been receiving 

 animal and vcgotablo colonist" for longer periods, go far to show that, 

 time being given, the sea actually affords facilities for the migrations of 

 the inhabitants of the land, greater than those of continuous continents. 



In referring to the ocean basins we should bear in mind that there are 

 three of these in the northern hemisphere— the Arctic, the Pacific, and 

 tho Atlantic. De Ranco has ably summoned up the known facts as to 

 Arctic geology, and more irecently Dr. G. M. Dawson has prepared for 

 the Royal Society of Canada a resume and map of what is known of the 

 geology of the Arctic basin,^ in comparison with Canadian geology. From 

 this it appears that this area presents from without inwards a succession 

 of older and newer formations from the Eozoic to the Tertiary, and that 

 its extent must have been greater in former periods than at present, 

 while it must have enjoyed a comparatively warm climate. The relations 

 of its deposits and fossils are closer with those of the Atlantic than with 

 those of the Pacific, as might be anticipated from its wider opening into 

 the former. Blandford has recently remarked on the correspondence of 

 the marginal deposits around the Pacific and Indian oceans,^ and Dr. 

 Dawson informs me that this is equally marked in comparison with the 

 west coast of America,* but these marginal areas have not yet gained much 

 on the ocean. In the North Atlantic, on the other hand, there is a wide belt 

 of comparatively modern rocks on both sides, more especially toward the 

 south, and on the American side ; but whilo there appears to be a perfect 

 correspondence on both sides of the 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 



' Continental and Island Life ; Botany of the • Cliallenger * Expedition. 



' Meeting of May 1886. The paper is not yet published. 



' A singular example is the recurrence in New Zealand of Triassic rocks and fossils 

 of types corresponding to those of British Columbia. A curious modem analogy 

 appears in the works of art of the Maoris with those of the Haida Indians of the 

 Queen Charlotte Islands, and both are eminently Pacific in contradistinction to 

 Atlantic. 



* Journal of Geological Society, May 188rf. Blandfoxd's statements respecting the 

 mechanical deposits of the close of the Palaeozoic in the Pacific area, whether these 

 are glacial or not, would seem to show a correspondence with the Permian conglome- 

 rates and earth-movements of the Atlantic area ; but since that time th'i Atlantic 

 has enjoyed comparative repose. The Pacific also seems to have reproduced the 

 conditions of the Carboniferous in the Cretaceous age, and seems to have been less 

 affected by the great changes of tihe Pleistocene. 



