THE G I-A CIA L-THEO R TES . 
93 
present state of things. We must, from a biological point of view, 
necessarily suppose a subarctic biosphere, adjacent to the ice; this 
Fig. 2. Zoogeographical map of Europe in the preglacial period. (Orig.) 
goes over towards the South into a thermophil and at last into a tropical 
fauna and flora. 
I should like to suggest that the Pleistocene period begins with 
