.RANGE BASE OR REFUGE AREAS 37 



species which could only exist under a mild climate 

 would be forced to the extreme south of Europe, 

 where, confined within ever-narrowing limits, they would 

 gradually die out. Only the more robust types, such as 

 stag, megaceros, urus, bison, horse, mammoth, woolly 

 rhinoceros — species capable of enduring some severity 

 of cold — would live on. The carnivores, however, might 

 be expected to thrive wherever their food supply was 

 sufficiently abundant, they would prey alike on the 

 denizens of the southern regions and the occupants of 

 less temperate latitudes. Most of them, therefore, were 

 enabled to endure all the climatic vicissitudes of the 

 glacial period, and many are recognized as still living 

 species." As will be seen, but one of these pachyderms 

 has managed to survive the Glacial Epoch, and that is 

 now an inhabitant of tropical Africa. To the present 

 writer there seems no reasonable doubt that this sur- 

 viving species, the hippopotamus, is the descendant of 

 individuals that entered Africa in late Miocene or early 

 Pliocene ages, when that region was invaded by so many 

 of the higher species of mammalia either from the east 

 or west, and that the Ethiopian portion of this species 

 never had any experience whatever of the Glacial Epoch, 

 The African elephant is said to be specifically distinct 

 from the European elephants of Pleistocene time (perhaps 

 northern and southern forms), but its remains, however, 

 have been found in North-west Africa, individuals which 

 were isolated there during the glacial climate of Europe 

 and exterminated by adverse conditions. Had con- 

 ditions been favourable for emigration to Africa of the 

 various large forms of Pliocene mammalia, there can be 

 no reasonable doubt that many species would have 



