6 THE WANDERINGS OF ANIMALS [CH. 



classical six ' regions,' which he named Palaearctic, 

 Ethiopian, Indian, Australian, Nearctic and Neo- 

 tropical. Those of the Old World were brigaded 

 as Palaeogaea and the two Americas as Neogaea, 

 a fundamental mistake. Broadly speaking these six 

 regions are equivalent to the great masses of land ; 

 they are convenient terms for geographical facts, 

 especially since palaearctic expresses the unity of 

 Europe with the bulk of non-tropical Asia. Un- 

 fortunately these regions are not of equal value. 

 Therefore, instead of keeping up the popular dis- 

 tinction between the Old and the New World, 

 Huxley in 1868 gave reasons (cf. Gallinaceous birds) 

 for dividing the world transversely, into an Arcto- 

 gaea or North World in a wider sense, comprising 

 N. America, Asia, with Europe and Africa ; and 

 Notogaea or South World, which he divided into 

 New Zealand, Australasia and Austro-Columbia, 

 the latter an unfortunate substitute for Neotropical. 

 Although applicable to various groups of animals, 

 the combination of S. America with Australia in 

 opposition to the rest of the world was gradually 

 found to be too sweeping a measure. The satis- 

 factory solution was provided by W. T. Blanford, 

 who in 1890 recognised three main divisions, namely 

 Australian, South American and the rest, for which 

 the already existing terms Notogaea, Neogea and 

 Arctogaea have come into general use. 



