THE GLACIAL PERIOD. 249 



plants. Arctic, northern, and alpine forms — reindeer, musk- 

 sheep, gluttons, marmots, tailless hares, and others no longer able 

 to live in countries and districts which were permanently sealed 

 in snow and ice — would advance towards the south, and, leaving 

 the upper parts of the Alps and other mountain-ranges, would 

 come down to inhabit the low grounds. The land-molluscs we 

 should expect would also be compelled to "migrate;" so that 

 when the cold had reached its climax and rivers were overflowing 

 ever and anon wide areas in Middle Europe, the waters would 

 sweep away groups of land-shells differing considerably from 

 those that now tenant similar positions in the same latitudes. 

 They would comprise many forms that are, in our day, confined 

 to high elevations and more northern regions, while the general 

 facies of the species would bespeak a colder and more humid 

 climate. 



Let me now ask the reader to recall the account given in 

 Chapters III. and IV. of the fauna and flora of Pleistocene times. 

 He will remember that distinct evidence was there adduced to 

 show that during some part of the Pleistocene Period such a 

 distribution of animals and plants as I have briefly indicated 

 above did actually obtain. "We found that reindeer and musk- 

 sheep were at one time occupants of Southern Prance, that the 

 woolly elephant lived in Spain and Italy, that the glutton fre- 

 quented the shores of the Mediterranean, that marmots and tail 

 less hares came down to the low grounds in Corsica, Sardinia, 

 and Northern Italy. I also mentioned the fact that traces of 

 an arctic flora had been met with at various points in the low 

 grounds of Central Europe, that pines and other trees of northern 

 and alpine habitats formerly grew upon the plains of France in 

 the latitude of Paris, and that the Cembran pine, now a native 

 of the higher Alps, descended to the low regions of Piedmont. 

 Again we found that the land -shells of Central Europe in 

 Pleistocene times implied climatic conditions which strongly 

 contrasted with those of the present, and their evidence pointed 

 in the same direction as that of the mammalia and the land- 

 plants. In all this we see that the Pleistocene Period and the 



