42 OSBORN. 



a marked increase especially in the number of reindeer. The 

 most important new living types are : the steppe antelope Saiga 

 prisca {tartarica), the moose Alces machlis, the lemming, Myodcs 

 lemimis, the Siberian jerboa Alactaga saliens, Hystrix, Lepus 

 timidjis. These constitute a distinct invasion of north Asiatic 

 forms into the southern steppes. 



Theory of a Mid or Second Glacial Advanxe 



In all the preceding summary a certain faunal succession is 

 noted consisting chiefly of elimination of southern types and in- 

 troduction of northern. 



WoLDRiCH ('96) maintains that all the loess and cave types 

 are of postglacial age — the tundre and steppe types alone rep- 

 resenting the last great glacial advance — after which came the 

 meadow or field (Weide-fauna) and the forest fauna (Wald- 

 fauna) ; he considers the alleged ice periods as mere local 

 oscillations. 



The possibility must also be freely admitted, as discussed by 

 BuLMAN ('93, p. 261), of the existence of south temperate types 

 remote from the Ice Sheet ; we find, for example, in southern 

 Alaska, a very mild climate in proximity to great glaciers ; 

 similar conditions may have existed in southwestern Ireland and 

 southern Europe. 



Other authors such as Boule, have maintained the glacial age 

 of the Tundre and Steppe fauna and the post-glacial age of the 

 Forest fauna. If they are correct the theoiy of an interglacial 

 or second glacial advance would lose its strongest support. It is 

 evident, however, that such a succession of faunas might recur 

 more than once. Nehring has observed in different localities 

 (Westeregeln, Thiede), the unquestionable interglaeial age of the 

 steppe fauna and he considers Schweizerbild as interglacial. 



d. Upper Mid-Pleistoeene. FJepJias priniigenius Stage, PoJdig 



As we enter the next succeeding life stage, namely, the 

 Loess and Cave Fauna of Central Europe, the stage ot ElepJias 

 prinngenius, RJujioeeros antiqtntatis or tieJwrJdmis and Raugife?- 

 tarandus we note the decline of RJdnoeeros vierekii and the ab- 



