SCHMIDT: ANIMAL GEOGRAPHY 777 



belief that continental connections are necessary to explain the existing pattern 

 of animal life on the continents, suggested that the correspondence of the con- 

 figuration of the Atlantic coast of South America with that of Africa was the 

 result of a drifting apart of land masses formerly joined, and rent asunder in 

 some past age. North America was thought to have drifted away from Europe 

 in the same way. It was found possible to fit the Australian and Antarctic con- 

 tinents against South Africa, also, with the Indian Peninsula and Madagascar 

 to fill the wedge-shaped gap between them, and to suppose that these land masses 

 had drifted away from Africa to the south and east and north as the Americas 

 had drifted to the west. The distribution of past continental glaciations and the 

 distribution of Paleozoic coal deposits were brought into harmony with the 

 theory of continental drift by assuming a different position of the poles during 

 Paleozoic times. The actual break-up of the vast unified original continent is 

 thought by "Wegener and his school to have occurred at the end of the Paleozoic. 

 Thus the theory is of little aid to those who had explained the distributions of 

 relatively recent groups like the birds and mammals by means of land connec- 

 tions, or to those who invoked them for distributions of groups at the level of 

 genera, which are demonstrably much more recent. To the more confirmed pro- 

 ponents of continental connections, however, this led merely to the outright 

 belief that the continents had drifted back and forth- — that they had been con- 

 nected, separated, and reconnected. 



The theory of continental drift has been received with considerable skepti- 

 cism by American geologists, many of whom had had no prior belief in any 

 continental connections other than those existing. The confirmation of the fact 

 that the continents are in isostatic balance merely confirmed their ideas of the 

 continents as vastly older than the life on them. In Europe a large group espoused 

 the Wegnerian ideas, and the literature of the subject, and finally the literature 

 of the controversy between drift and anti-drift proponents is now vast. Much of 

 this literature, however, still assumes as axiomatic that a past connection of the 

 continents is necessary to explain the present distribution of land life. In the 

 very year when Wegener proposed his theory, this assumption was shown by 

 William Diller Matthew to be invalid. 



Climate and Evolution 



The publication of Matthew's Climate and Evolution in 1915 was an event 

 of primary importance in the field of animal geography. This paper sums up 

 the accumulated paleontological evidence for the Tertiary distribution of mam- 

 mals in a masterly way; it re-enforces the belief in the general permanence of 

 continents, which had been a cardinal point with Wallace, but which had come 

 to be more and more widely disregarded; it reverses a long accepted criterion 

 for the place of origin of mammalian groups especially and of other animals in 

 broad outline; and it offers a principal cause for the long-term dispersal of 

 species, and of faunas with their environments, that links the subject of distri- 

 bution with the whole course of evolution, and with a reasoned interpretation 

 of the geological record. This work, in direct contradiction in many of its well- 

 supported statements with the contemporary literature of animal geography, 

 could not fail to have an extraordinary influence. A considerable number of 



