CLIMATE OF PLEISTOCENE PERIOD. 43 



foxes, musk-sheep, gluttons, and other alpine and northern 

 species, were settled inhabitants of those low grounds of Europe 

 that are now occupied only by the temperate group. It does 

 not by any means follow, however, that the arctic or northern 

 group of animals was distributed over all Europe, from the ex- 

 treme north down to Erance, at one and the same time. The 

 cold climatic conditions that forced them from their head-quarters 

 must have come on gradually, pushing them slowly farther and 

 farther to the south ; so that when at last they came to occupy 

 the low grounds of France and the south of England, it may well 

 have been that the regions farther north were too inhospitable 

 even for them. Indeed, we can hardly escape from this con- 

 clusion when we bear in view the geographical position of 

 North-western Europe. But to this point we shall return after 

 we have considered certain geological evidence which will come 

 before our attention in the sequel. 



