RANGE BASE OR REFUGE AREAS 57 



across that newly-formed land and entered Euro-Asia, 

 where, as we know, their remains abound in the Mio- 

 cene deposits of Greece and elsewhere. This Law of 

 Dispersal also renders it impossible for any " old South 

 Palaearctic fauna" to have "poured into Africa," and 

 to have " finally overran the whole continent " (Wallace, 

 Geographical Distribution of Animals, vol. i., p. 288) — a 

 temperate fauna entering a tropical area ! We need no 

 " persistence through long epochs of barriers isolating 

 the greater part of Africa from the rest of the world," 

 as Dr. Wallace insists, to account for the absence of 

 such groups as bears, moles, camels, deer, goats, sheep, 

 or such genera as Bos and Sns ; a law forbidding the 

 southern emigration of such types is sufficient to ex- 

 plain the facts, without invoking more or less hypotheti- 

 cal geographical obstructions. 



Many of these facts undoubtedly point to a much 

 greater land surface in the Southern Hemisphere as well 

 as to the former existence of a vast Antarctic land — 

 a South Polar continent or continents with extensive 

 land connections stretching far to the north. So long 

 as this Antarctic continent is ignored w^e shall never 

 arrive at a sound conclusion on the grand question of 

 geographical dispersal. The South Pole must have been 

 the centre of a great and dominant avifauna, of which 

 the Charadriidse, the Anatidae, and the Procellariidae (all 

 groups in which migratory habits are dominant) were 

 strongly-marked features. The great changes which 

 that vast region has undergone and which have utterly 

 exterminated (so far as we know) the avifauna dwell- 

 ing within it, has been the cause of a great northern 

 dispersal or range contraction southwards, especially of 



