SCHMIDT: ANIMAL GEOGRAPHY 785 



Pleistocene. In certain places there is a succession of deposits in which the life 

 of the tundra (lemmings, reindeer, arctic fox) is found to be replaced by animals 

 characteristic of the open steppe (such as lion, hyena, hamster, and jerboa), and 

 this in turn by the remains of the aurochs and the modern fauna. He interprets 

 this as reflecting the succession of climates and of vegetations associated with the 

 retreat of the ice. In one of my own papers, I have been able to demonstrate a 

 close parallel to the European westward extension of the steppes of Central Asia, 

 in the eastward range of a part of our North American Great Plains fauna in the 

 so-called "Prairie Peninsula" between the Great Lakes and the Ohio (Schmidt, 

 1937). 



Paleoclimatology in relation to the Pleistocene glaciations rests on abundant 

 and conclusive evidence, with the extraordinary advantage in recent years of 

 more exact dating by Carbon-14 analysis. As applied by Brooks and others to 

 ancient climates, with different configurations of the continents, it has the same 

 extremely speculative nature as the paleogeography on which it depends. 



At the very root of the problem of geographic range of the species we come 

 upon the problems connected with the range of the individual animal, and more 

 especially of the individual mated pair of breeding aggregations. Illuminating 

 observations have been made on the establishment of well-defined territories in 

 relation to their nests and to their feeding ground by birds, and these are being 

 extended by critical observations to other groups of animals of the most diverse 

 type. AVe are fortunate to have a summary of this important field of study by 

 Mrs. Margaret Morse Nice "The Role of Territory in Bird Life" (1941), which 

 includes a sketch of the history of the idea. The phenomenon is made conspicuous 

 among birds by the songs of the males, which seem to be effective in establishing 

 their spaced territories. The phenomenon in other animals may be complicated 

 by the degree of social organization; the subject is summarized in The Principles 

 of Animal Ecology (Alice et al., 1949). 



Island Life 



The problem of accounting for the life on islands in the sea has been close 

 to the heart of animal geography from the earliest beginnings of thought. It 

 became a crucial problem to Darwin in relation to giving up the doctrine of 

 special creation in favor of a long-continued natural process. He at once set 

 about making experiments on the viability of seeds after immersion in sea water; 

 and began to assemble the observations of accidental transport of small animals 

 by large, and of animals in general by floating vegetation, which he reports in 

 the Origin of Species. Dispersal and capacity for dispersal are, in fact, basic to 

 the whole of animal and plant geography. It is the denial of any capacity for 

 transoceanic dispersal that lies at the root of the whole bridge-building contro- 

 versy, and in part at the root of the arguments for continental drift. So con- 

 vinced are the "connectionists" that there can be no overseas transport of land 

 animals that the Galapagos Islands and the Hawaiian Islands have been thought 

 to be quite as necessarily linked to the nearest continent as Britain and Borneo. 

 It is one of the principal accomplishments in animal geography in recent decades 

 to make a renewed analysis of such island life with the conclusion that the islands 

 are indeed oceanic, and that the very existence of their land fauna proves its 



