INTRODUCTION 



35 



III. Geographic or Space Distribution of Mammals 



Zoogeography. — We have seen above that we owe to Biiffon (p. 19ff.) 

 and Cuvier (p. 22 ff.) the beginnings of the fascinating study of geographic 

 distribution in past and present times. Cuvier clearly saw that the mam- 

 mals which we find at any point on the earth to-day may not have origi- 

 nated there but have had their homes or centers of origin at far distant 

 points. It has since become more and more evident that only through 

 paliPontology can we connect the present distribution of mammals with 

 their distribution in the past, and set forth a science of geographic dis- 

 tribution, or zoogeography, which will be in harmony with l)oth sets of facts. 

 The importance of this more thorough study of present and past geo- 

 graphic distribution was recognized by Alexander von Humboldt. The 

 first exact attempt to compare the animals and plants of the present and 

 past in a single region was that of Edward For])es in his remarkable paper 

 on the geological relations of the fauna and flora of the British Isles. ^ In 

 this paper he attempts to distinguish those animals and plants which are 

 native to the British Isles from the immigrants, and among the latter he 

 attempts to trace the sources, or geographic centers from which they came. 



Many of the principles of zoogeographic distribution were clearly un- 

 derstood by Darwin and set forth in ''The Origin of Species" in the year 

 1859, and it is noteworthy that in the same year Philip Lutley Sclater ^ 

 divided the world into six zoogeographic regions, as follows: 



Neog.ea 



Pal.eog.ea 



f Nearctic, 

 1 Neotropical 



Pala^arctic 



Indian 



Ethiopian 



Australian 



Boreal Zone 

 Tropical Zone 

 Boreal Zone 

 Tropical Zone 

 Tropical Zone 

 Austral Zone 



North America 

 South America 

 Europe and Asia 

 Southern Asia 

 Africa 

 Australia 



We observe that Sclater's was an east and west division, or a neiv and 

 old world division, based on the lines of longitude rather than of latitude. 

 Murray's "Geographical Distribution of Mammals," published in 1866, 

 served to arouse further investigation of this subject.^ 



The six great regions of Sclater were subsequently adopted in their en- 

 tirety ])y Ahred Russcl Wallace in his great work of 1876, "Geographical 

 Distribution of Animals . . . " * the first comprehensive attempt at this 



' Forbes, E., On the Connection between the Distribution of the Existing Fauna and 

 Flora of the British Isles with the Geological Changes which have affected their Area. Mem. 

 Geol. Siirv., Vol. I, 1846. 



- Sclater, P. L., On the General Geographical Distribution of the Members of the Class 

 Avcs. Jour. Proc. Linn. Soc. (ZooL), Vol. II, p. 130 (1857), 1859. 



■'' Murray, A., The Geographical Distril)ution of Mammals, London, 1866. 



■• Wallace, A. R., Geographical Distribution of Animals, with a Study of the Relations 

 of Living and Extinct Faunas as Elucidating the Past Changes of the Earth's Surface, 2 vols. 

 Loudon, 1876. 



