l6 ON THE GEOGRAPHY OF ANIMALS. 



turalist more especially, to be borne in mind than this. 

 What beings can be more dissimilar than an African 

 negro and a Greek Caucasian ? Yet who has ventured 

 to pronounce in what regions the Ethiopian form ac- 

 tually blends into that of the Caucasian ? or this, again, 

 into the Mongolian ? Such are the difficulties that 

 "will for ever baffle all attempts at unexceptionable 

 definition, or every effort to define the precise limits of 

 natural groups or zoological regions. Nature, in fact, 

 seems to abhor those arbitrary rules, with which man 

 has invested her operations ; and which, for centuries, 

 have shackled the progress of zoological knowledge. 



(21.) In attempting, therefore, to give a more accu- 

 rate definition to the foregoing divisions, we are com- 

 pelled to fill up the outline, at the best with diffidence, 

 and, in some cases, by conjecture. The following, how- 

 ever, may be regarded as some approximation to the 

 truth. 1. The European or Caucasian range includes 

 the whole of Europe, properly so called, with part of 

 Asia Minor, and the shores of the Mediterranean : in 

 Northern Africa the zoological peculiarities of this re- 

 gion begin to disappear ; they are lost to the eastward 

 of the Caucasian mountains, and are blended with those 

 of Asia and America to the north. 2. The Asiatic range : 

 comprehending the whole of Asia east of the Ural 

 mountains, a natural and well-defined barrier between, 

 the two continents. The chief seat of this zoological re- 

 gion is probably in central Asia ; its western confines 

 blend into the European towards Persia, and disappear 

 on the west of the Caucasian chain ; it is united to the 

 African range among the provinces of Asia Minor ; and 

 is again connected with Eui'ope, and also with America, 

 by the arctic regions of the three continents ; finally, its 

 most southern limits are marked by the islands of Java 

 and Sumatra, where the zoological character of the Aus- 

 tralian region begins to be apparent. 3. The American 

 range. United to Europe and Asia at its northern limits, 

 this region or province comprehends the whole of the 

 New World ; but into which it blends at the other ex_ 



