EXTINCT CONTEMPORARY MAMMALS. 285 



tinct mammalia are in truth geologically recent; and when we 

 further consider the fresh condition in which some of them 

 occur in the ice -gravels of Siberia, we are compelled to 

 withhold from them an unlimited antiquity. It is a sound 

 maxim in paleontology, that the greater the divergence of 

 any species from existing species, the greater its antiquity ; 

 and founding on this rule, the mammoth, mastodon, and 

 their huge congeners, cannot lay claim to the vast antiquity 

 which many geologists have been so anxious to assign to 

 them. Still, with all these facts and allowances, it must 

 ever be remembered that the occurrence of hairy elephants 

 and woolly rhinoceroses in Western Europe bespeaks a 

 much colder climate than the present ; and as changes in 

 climate can only arise from great physical changes, great 

 alterations must have taken place in the external conditions 

 of our continent. Such changes are ever slow and gradual, 

 and thus we are compelled to admit a high antiquity to the 

 fashioners of these flint implements and their contempora- 

 ries, the mammoth and mastodon. 



Indeed, the existence of a boreal climate necessitating 

 shaggy coverings for the elephant, and rhinoceros, would 

 seem to carry us back to times immediately post-glacial 

 that is, to the time when the last traces of the glacial 

 epoch were gradually being effaced by the advent of a 

 more genial and equable climate. Were this the case, 

 the appearance of man in Europe would be coeval with 

 the earlier Post-tertiaries, and his antiquity much higher 

 than the majority of geologists are yet prepared to ad- 

 mit. But his occurrence in Europe does not settle the 

 question of his first appearance on the globe. On the 

 contrary, the human race, in one or other of its varieties, 

 may have existed for ages in Asia or Africa before it 

 found its way to Western Europe, and, indeed, all that we 

 know of language and ethnology seems to point to this 



