670 EEPOET— 1889. 



is then attempted to explain the previous arrangement of the land, and this is done 

 too often without appealing to the physical evidence at all. In tracing geogra- 

 phical changes in the past, it would seem more reasonable to adopt an opposite 

 method ; but in the great majority of cases affecting the distribution of animals, it 

 would be wiser in the first place to assume the status quo, and fall back when 

 that fails on the physical evidence of the presumed changes. 



