232 ANNALS NEW YORK ACADEMY OF SCIENCES 



only a more extensive glaciation but that the snow line was 100m. lower. 

 It is also estimated that the climate of the Riss was one-twelfth more 

 severe than that of the Wiirm. 



In northern Germany only three great glacial advances are recorded, 

 while still farther north, in Scandinavia, there was in a sense only one 

 Glacial epoch, since the ice cap never retreated so far as to permit of 

 interglacial deposits. This is in accordance with the anthropological 

 fact that only toward the close of Postglacial times does Scandinavia 

 show traces of human habitation in the arrival of the Neolithic men; 

 whereas in France and Germany there is evidence of human habitation 

 as early as the Second and Third Interglacial Stages. 



In the meantime American geologists have also discovered similar 

 proofs of four successive glacial advances and more temperate inter- 

 glacial stages. The correlation of these conditions in the New and Old 

 Worlds suggested by Penck, Chamberlin and others has recently been 

 reviewed with great precision by Leverett, 19 to whose work we shall fre- 

 quently refer. The most recent results of geologic and anthropologic 

 correlation with some original modifications are graphically presented in 

 the accompanying diagram (Fig. 5) by the author and Reeds. 20 



The river terraces are of great importance both in geology and in an- 

 thropology. In general the "high terraces" belong to the earlier glacia- 

 tions and the "low terraces" to the latest. Thus the "high terraces" of 

 the Alpine region belong to the Riss or glaciation III ; in the valley of 

 the Rhine the "high terrace" is visible near Basle; the "low terrace" of 

 the "Wiirm or glaciation IV occupies vast surfaces on the upper Rhine 

 and contains a mammoth (E. primigenius) fauna. The "high terraces" 

 in the Paris basin reach 30m. above the level of the Seine, while the "low 

 terraces" are only 5m. above the level of the Seine and subject to floods ; 

 the "high terraces" in the valley of the Seine contain the First Inter- 

 glacial (E. meridionalis, E. stenonsis) fauna, while the "low terraces" of 

 the Seine and of the Somme contain the Second and Third Interglacial 

 fauna (E. trogontherii, E. antiquus, and D. merckii) . 



DOTATION OP THE PLEISTOCENE 



The Pleistocene was estimated by the American geologist Dana (1874) 

 to be equal to about one-fourth of the entire Csenozoic Era, i. e., 700,000 

 years. By Ward (1885) and Williams (1895) it has been estimated at 



19 LeveretTj Frank : "Comparison of North American and European Glacial Deposits." 

 Zeitschr. f. Gletscherkunde, Vol. iv, pp. 241-316. 1910. 



20 Reeds, Chester A. : Dr. Reeds has prepared the climatic curve from data furnished 

 by Penck, Leverett, Taylor, Chamberlin, Salisbury, Geikie, Schmidt, Coleman and Osborn. 

 Dated October, 1914. 



