166 THE EARLIEST MEN 



LATER GEOLOGICAL PERIODS. 



Tertiary. 



Eocene. Here there is no question of man. 



Oligocene. r (Wanting in Britain). At the 



I end of this Thenay flints ; and 



Miocene. 1 at the beginning of Miocene 



^Aurillac flints. 



Pliocene. At the upper part of this, or at the 

 lower part of the next, is the Red or 

 Norwich Crag, associated with the 

 rostro-carinate forms. 



Quaternary. 



Pleistocene or Glacial. Recent, which brings 

 us down to the present moment. 



Incidentally some points in connection with 

 these periods will arise in our consideration of the 

 relics of early man. There is only one point which 

 must be dealt with here, and that is the question 

 of the Glacial Period. This is a matter which is 

 more fully discussed in the next article. Here it 

 need only be said that it was a period during 

 which large tracts of the world now occupied by 

 mankind were rendered uninhabitable by glaciers 

 of enormous magnitude and other accompani- 

 ments of an Arctic climate. 



If we try to make any estimate of the actual 

 number of years required for the events associ- 

 ated with the Glacial Period we shall find our- 

 selves involved in immense difficulties. 



In books of history, we find it set down that 

 William the Conqueror reigned from A.D. 1066 

 to 1087. Less sharp-cut, but sufficiently definite, 



