BOOKS AND CURRENT LITERATURE 



Distribution and Origin of Life in America. — This great work 1 

 1 >y Dr. Seharff will be welcomed by all students of distribution, whether 

 the author's conclusions, which lead far from beaten paths, are accepted 

 or not. It is a veritable mine of wealth in its extraordinary accumula- 

 tion of data from all available sources, and its value is enhanced by the 

 large number of recent observations drawn from living writers and the 

 author's own extended knowledge in his special field. 



Beginning with northern North America, the author takes the ground 

 that we possess no direct evidence for the general belief that the climate 

 of Greenland was much colder during the Glacial Epoch than it is now, 

 and that no special reason can be adduced why the present flora of 

 Greenland should not have survived the Ice Age. The well-known 

 features of distribution in the White Mountains, Labrador and the 

 region to the westward, though giving abundant evidence of extensive 

 migration, calling for the assumption that land connections with Europe 

 and Asia existed long before the Glacial Epoch, are interpreted on the 

 theory of survival over discontinuous areas rather than as evidences 

 of a general movement to higher latitudes ami altitudes during the 

 retreat of the ice. In fact the author distinctly states his belief that 

 the climate of boreal North America during the Ice Age, though much 

 more humid than at present, so that it led to extensive glaciation on 

 all higher mountain ranges, was not arctic but temperate, and that in 

 many parts within the so-called glaciated area there existed islands 

 where life was abundant and survived to the present day. The author 

 holds that long before the commencement of the Glacial Epoch the 

 animals and plants from Labrador found their way southward to the 

 White Mountains. It may well be that such far-reaching conclusions 

 will not find general acceptance, but at all events they call for a thought- 

 ful hearing. 



A large amount of space is necessarily given to the several great bio- 

 logical regions which succeed each other on the long way from Alaska 

 to Patagonia. Evidence is brought forward which seems to point 



1 Seharff, R. F. Distribution and Origin of Life in America. Pp. 497, figs. 21. 

 New York, The Macmillan Company. 1912. ($3.00.) 



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