MATTHEW, CLIMATE AND EVOLUTION 315 



subject or the fossil record. The view that during the Glacial Epoch 

 the glaciers were confined in this country to the higher mountain ranges^^^ 

 is one that even a biologist is hardly excusable for upholding. Nor does 

 it seem that anyone discussing the Tertiary geography of North America 

 should be so little informed as to suppose^^" that the eastern and western 

 portions of the continent were separated during the Eocene by an ocean 

 barrier. In his argument against the permanency of the ocean basins, 

 Scharff is, on the other hand, able to quote high authority. But the 

 weakness of the argument is nevertheless apparent. That there have 

 been great changes of level along certain lines of disturbance has never 

 been questioned. But the conclusion that the continental platforms have 

 never been submerged to abyssal depths, based upon the entire lack of 

 abyssal deposits in their geological succession, is not disproved but rather 

 confirmed by the recognition of abyssal deposits on an oceanic island 

 lying along a line of high disturbance. For that merely proves that 

 abyssal deposits are recognizable as such when they do occur, absence 

 from the continental platforms remains untouched. Nor does the oc- 

 currence of ancient sedimentary and metamorphic rocks on some, espe- 

 cially of the larger, oceanic islands afford any evidence that they are 

 remnants of former continents. The same processes of sedimentation, 

 regional metamorphism and orogenic upheaval must of necessity occur 

 in any oceanic island of considerable size and antiquity, and produce 

 similar results both stratigraphic and petrographic. Moreover, if such 

 islands lie in a line of disturbance which is continued under the ocean 

 to an adjacent continent the same earth-movements may well affect both 

 areas without raising the intervening region above the abyssal depths in 

 which it now lies. 



Dr. Scharff adopts Ameghino's correlations of Argentine formations, 

 and Von Ihering's assertion that the continent of South America did 

 not exist as a single land mass until late in the Tertiary. I may note 

 by the way that Ortmann^^^ not long ago, in reviewing Pfeffer's^^^ essay 

 on the zoogeographical relations of South America, rebuked him severely 

 for not being aware of this "undoubted fact," which he declared was not 

 a theory at all. The real facts are that marine and fresh-water forma- 

 tions of Jurassic, Cretaceous and early Tertiary age occur extensively in 

 the interior of South America, indicating that the broad low-lying in- 

 terior of that continent was periodically flooded by shallow seas. The 

 conditions parallel those of the North American continent very closely. 



i=» Op. cit., pp. 46 £f. 



^^o Ibid., p. 357. 



131 A. E. Ortmann : Amer. Nat., vol. xxxix, pp. 413-416. 1905. 



182 G. Pfeffbb ; Zool. .Tahrb., Suppl. 8. pp. 407-442. 1905. 



