250 THE STOKY OF THE EARTH AND MAN. 



streams and mephitic vapours which threaten the 

 intellectual obscuration of those who should be their 

 successors. 



If we pass from the Eocene to the Miocene, still 

 confining ourselves mainly to mammalian life, we find 

 three remarkable points of difference (1) Whereas 

 the Eocene mammals are remarkable for adherence to 

 one general type, viz., that group of pachyderms most 

 regular and complete in its dentition, we now find a 

 great number of more specialised and peculiar forms; 

 (2) We find in the latter period a far greater propor- 

 tion of large carnivorous animals ; (3) We find much 

 greater variety of mammals than either in the Eocene 

 or the Modern, and a remarkable abundance of species 

 of gigantic size. The Miocene is thus apparently the 

 culminating age of the mammalia, in so far as physical 

 development is concerned ; and this, as we shall find, 

 accords with its remarkably genial climate and exu- 

 berant vegetation. 



In Europe, the beds of this age present, for the 

 first time, examples of the monkeys, represented by 

 two generic types, both of them apparently related 

 to the modern long-armed species, or Gibbons. 

 Among carnivorous auimals we have cat-like crea- 

 tures, one of which is the terrible Machairodus, dis- 

 tinguished from all modern animals of its group by 

 the long sabre-shaped canines of its upper jaw, fitting 

 it to pull down and destroy those large pachyderms 

 which could have easily shaken off a lion or a tiger 

 Here also we have the elephants, represented by 



