10 THE MIGRATION OF BIRDS 



west. Birds of the same species actually crossed 

 paths, travelling in contrary directions (16). 



The above grouping applies to the British avifauna, 

 but a somewhat similar arrangement might be 

 made of the birds of any particular area, large or 

 small. The grouping of birds for the study of 

 Geographical Distribution is of little consequence 

 in connection with migration, but the mapping of 

 the world into various ornithological rather than 

 zoogeographical regions is of considerable import- 

 ance, both for convenience in tracing the ranges 

 of migrants, and in the discussion of the history of 

 migration, which almost certainly began in the 

 form of short wanderings from the centres of dis- 

 tribution. It is of comparatively small importance 

 what boundaries we take for the various regions ; 

 these depend largely upon the view of certain 

 ornithologists as to which groups of birds shall be 

 considered as typical of the regions in question. 

 Sclater's six regions are perhaps the most universally 

 used. They are as follows : 



1. Palaearctic, embracing the whole of Europe 

 and northern Asia. 



2. Ethiopian Africa, Arabia, Madagascar and 

 roughly half of the Atlantic and Indian Oceans. 



3. Indian, including India, Further India, Southern 

 China, the western portion of the Malay Archipelago 

 and the Chinese Seas. 



