8 MAN AND THE GLACIAL PERIOD. 



na, we will proceed to give, first, a brief enumeration and 

 description of the ice-fields which are still existing in the 

 world ; second, the evidences of the former existence of 

 far more extensive ice-fields ; and, third, the relation of 

 the Glacial period to some of the vicissitudes which have 

 attended the life of man in the world. 



The geological period of which we shall treat is vari- 

 ously designated by different writers. By some it is simply 

 called the " post-Tertiary," or " Quaternary " ; by others 

 the term " post- Pliocene " is used, to indicate more sharply 

 its distinction from the latter portion of the Tertiary 

 period ; by others this nicety of distinction is expressed 

 by the term " Pleistocene." But, since the whole epoch 

 was peculiarly characterised by the presence of glaciers, 

 which have not even yet wholly disappeared, we may 

 properly refer to it altogether under the descriptive name 

 of " Glacial " period. 



