74 THE MAMMALIA. 



unable to admit. At all events, the period within 

 which the European mammoths and their asso- 

 ciates, the American mastodons, the giant sloths 

 and giant armadilloes, rapidly died out, must have 

 been very short in a geological sense of the word. 

 But there was no general destruction or dying out, 

 only a portion of the species became altogether 

 extinct, e.g. the horses of America : one portion 

 found means of differentiating, to adapt themselves 

 to a new locality, or returned at a later period to 

 their old home when the hindrances to their ex- 

 istence no longer prevailed. Among those inhabit- 

 ants of the earth able to cope with the existing 

 difficulties was Man, who may, with positive 

 certainty, be seen struggling through the whole 

 Diluvial period. All these signs of life succumbed, 

 or had partially to withdraw, before the great ice 

 formations which took place during the sub- 

 divisions of the Diluvial age. The cloak of ice 

 evidently of many thousand years' duration which 

 still persistently envelops Greenland, while Norway 

 and Sweden, in the same latitudes, enjoy the most 

 splendid green summers, gives us a vivid picture 

 as to how we have to conceive the enormous 

 glacial formations in Europe and America during 

 the Diluvial period. 



