appendix: review and critique 



477 



Glacial, but Gagel describes it as Second Glacial, and does not recognize 

 any First Glacial in Germany. This, in Leverett's opinion, is an error. 

 The matter of the extent of the Fourth Glacial drift in Germany is not 

 fully settled, but there is an unanimous agreement that it extends much 

 farther than the Baltic moraine, which J. Geikie considered as its limit. 

 fSoergel (1919.1, figure 12, page 100) presents a map (figure 14) show- 



Schematische Ddnstellung d<?r 

 FidximdUtdnde der einzelwn Phdsen der letzteo Eiszeit. 



Jm I- Hau pt vorst 056 Maximalstdn d I-Pti d6c. 



ndft wreiste mm. n-HauptvorstoSu 



IliiilH 

 g Phasg Maxirodlstand tm 



JD Oder bdltiselwn Yonstoss. 



=*.100KTn 



Figure 14. — Retreat Phases of the Fourth Glaciation in North Central Germany 



After Soergel. 



ing the stages which have been determined for the retreat of the ice of 

 the Fourth Glaciation in north central Germany.] Leverett regards as 

 very instructive the map in Werth's book, ,k Das Liszeit alter," published 

 in 1909, which sets forth four of the chief morainic systems of the Fourth 

 Glaciation in Europe. 



(9) Leverett considers that there is distinct advantage in the simple 

 fourfold classification of the Ice Age, such as is presented in the Osborn- 



