12 THE WANDERINGS OF ANIMALS [OH. 



resulting regions tallied neither in extent nor in 

 numbers, although most of them gravitated more and 

 more towards three centres, namely Australia, South 

 America and the rest of the world. 



Let us take up the account with the establishment 

 of the Noto- Neo- and Arctogaea in the year 1890, when 

 Trouessart of Paris, by adding an arctic and an ant- 

 arctic region to those of Wallace, increased them to 

 eight, but he also suggested that these might be recom- 

 bined into three 'zones,' namely an Arctic (=Heilprin's 

 and Newton's Holarctic), an Antarctic (South America 

 and Australia) and an Old- World tropical zone. The 

 latter idea was taken up in 1892 by Allen of New 

 York who, after a study of the Mammalia, joined the 

 Old Oriental and Ethiopian regions into one Indo- 

 African. Meanwhile A. Heilprin of Philadelphia in 

 1887 accepted the Neotropical, Australian, Oriental 

 and Ethiopian regions, but at the suggestion of 

 A. Newton combined the Nearctic and Palaearctic 

 as Holarctic ; further, he carved out two new 

 regions, one Mediterranean, the other Sonoran ; for 

 the Nearctic, now reduced to Canada and Alaska, 

 together with the Palaearctic Blanford suggested the 

 name Aquilonian, whilst for the Sonoran he revived 

 Cope's term Medi-Columbian. We have only to add 

 that some Zoo-geographers treat as principal regions 

 what others consider as subregions, that some speak 

 of eight realms and others of only three regions, and 



