XVII 



GEOGRAPHICAL DISTRIBUTION OF ANIMALS 

 By Hans Gadow, M.A., Ph.D., F.R.S. 



Strickland Curator and Lecturer on Zoology in the University of Cambridge. 



The first general ideas about geogi-aphical distribution may be found 

 in some of the brilliant speculations contained in Buffon's Histoire 

 Naturelle. The first special treatise on the subject was however 

 written in 1777 by E. A. W. Zimmermann, Professor of Natural Science 

 at Brunswick, whose large volume, Specimen Zoologiae Geographicae 

 Quadrupedum..., deals in a statistical way with the mammals ; im- 

 portant features of the large accompanying map of the world are the 

 ranges of mountains and the names of hundreds of genera indicating 

 their geographical range. In a second work he laid special stress 

 on domesticated animals with reference to the spreading of the 

 various races of Mankind. 



In the following year appeared the Philosophia Entomologica 

 by J. C. Fabricius, who was the first to divide the world into eight 

 regions. In 1803 G. R. Treviranus^ devoted a long chapter of his 

 great work on Biologie to a philosophical and coherent treatment of 

 the distribution of the whole animal kingdom. Remarkable progress 

 was made in 1810 by F. Tiedemann^ of Heidelberg. Few, if any, of 

 the many subsequent Ornithologists seem to have appreciated, or 

 known of, the ingenious Avay in which Tiedemann marshalled his 

 statistics in order to arrive at general conclusions. There are, for 

 instance, long lists of birds arranged in accordance with their 

 occurrence in one or more continents: by correlating the distribu- 

 tion of the birds with their food he concludes " that the countries of 

 the East Indian flora have no vegetable feeders in common with 

 America," and " that it is probably due to the great peculiarity of 

 tlie African flora that Africa has few phytoi)hagous kinds in common 

 with other countries, wliilst zoophagous birds have a far more 

 independent, often cosmoitolitan, distribution." There are also 

 remarkable chapters on the influence of environment, distribu- 

 tion, and migration, upon the structure of the Birds ! In sliort, 



^ Biolof/if Oder PhilosopltU' der lebenden NuUir, Vol. ii. Oottingeu, 1803. 

 * Anatotnie und Nalurgtcchicltte der Vi'xjel. Heidelberg, 1810. 



