American Museum of Natur.il Ili^tdri 



SIMILAR INHABITANTS OF DIVERSE CLIMATES 



If each region is inhabited by plant and animal types especially designed for it, we 

 want to know why variations of the same type — dog, for example — occur as timber 

 wolf in the cold regions of North America and as wild dogs in the temperate regions 

 of Africa 



those found elsewhere, but they are, as a rule, most closely "related" to the 

 inhabitants of the nearest mainland (with which such islands were apparently 

 connected in the past). Facts of this kind can be explained if we assume that 

 ail organisms are derived from ancient forms, with modifications. But they 

 cannot be easily explained in any other way. 



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