THE pal.5:arctic and ne arctic regions 24-2^ 



birds we might meet with, two would be generically un- 

 known to the student of the Palsearctic avifauna. There 

 is probably no such amount of difference as this between 

 any two adjacent regions, except perhaps between the 

 Oriental and Australian, the latter admittedly the most 

 isolated on the globe. 



I have now shown, by a careful comparison of their 

 mammalia and birds, that the Palaearctic and Nearctic 

 Regions, instead of being so much alike that they should 

 be united to form a single region, are really exceptionally 

 distinct. They are certainly much more distinct than are 

 the Oriental and Ethiopian Regions, and are probably 

 quite as distinct as are any two conterminous regions. 



I feel confident, therefore, that any naturalist who will 

 study the materials I have here brought together in a 

 form to admit of easy comparison, will arrive at the con- 

 clusion that the system of Zoological Regions established 

 by Dr. Sclater cannot be improved by the union of two 

 such fundamentally distinct areas as are those which he has 

 termed the Palsearctic and Nearctic Regions. This con- 

 clusion entirely harmonises with the facts of plant-distri- 

 bution as popularly described in the last two chapters. 



