404 Evolution and Distribution of Fishes 



volcanic action, in larger part probably to earth-shrinkage, 

 or to a combination of both. The faults that can be traced 

 across Scotland in Old Red rocks, the folding of later 

 Carboniferous rocks there, the upheaval and dislocation 

 of rocks during formation of the Andes and the Rocky 

 mountains from Cretaceous to late Tertiary time, the 

 gigantic "rifts" that formed in Africa during Tertiary 

 times, and the displacements in South African and East 

 Australian rocks all testify to violent cataclysmic changes 

 in the earth's surface-crust at least. 



Lastly, the gradually increasing elevation of strata into 

 higher and higher folds or ridges that ultimately constitut- 

 ed such ranges as the Andes and Rocky Mountains, the 

 Alps, the Himalayas, etc. form phenomena of striking 

 significance. Now, if such phenomenal and widespread 

 changes have occurred in mxany of the geologic epochs, it is 

 alike unscientific and contrary to all organic evidences to 

 assert, that present-day seas and oceans did not undergo 

 as extensive and fundamental changes as did the land- 

 masses, specially if multitudes of distributional facts seem 

 only to be explicable when such changes are admitted. 



Thus to suppose that the gigantic and repeated "rift" 

 faults which cross central Africa were confined in their 

 origin almost wholly to the continent itself, and did not 

 affect areas east and west that now are deep under the sea, 

 is to demand an impossibility. So in the subsequent con- 

 text the writer accepts in the main the conclusions of Suess, 

 DeLapparent, Neumayr and Koken, as well as the addi- 

 tional evidence cited by Arldt, and many geographic as well 

 as geologic details that the writer has brought together in 

 favor of these views, in part from the plant, in part from 

 the animal side. 



But no more sensitive group probably than the fishes 

 could be selected as a test of these views, for they clearly 

 demonstrate in their historic evolution that wide-spread 

 and fundamental alterations in sea and land have constantly 

 occurred in past times. 



The writer proposes to study the fishes now in their 

 geographic and geologic relations, starting from the exist- 

 ing species, genera and families. The groups that, from the 



