418 THE AGE OF MAMMALS 



entirely distinct and separate, as in the lower deposits of Thiede near 

 Braunschweig, above cited. More often they are successive, or superposed 

 upon each other, even in the same localities ; thus in the loess near Wiirz- 

 burg, Bavaria, Nehring ^ has recorded both a tundra and a steppe fauna, 

 including, beside the still living types, the woolly rhinoceros, the mammoth, 

 the urus, and the bison. In other localities Nehring has observed and most 

 accurately recorded a vertical succession of tundra, steppe, and forest mam- 

 mals. 



Our realization of the long periods of time in which these successive 

 deposits with successive faunas accumulated is intensified ])y their associa- 

 tion with successive stages in the evolution of human culture. The most 

 famous instance of this kind is that recorded by Nehring ^ in the remarkable 

 grotto at Schweizersbild near Schaffhausen, in which the following layers 

 appear : 



Neolithic 5. Gray culture layer, forest fauna 



Palaeolithic 4. Upper Breccia, or ' upper rodent ' layer, steppe fauna 

 Palaeolithic 3. Yellow culture layer, palaeolithic 'reindeer age,' steppe fauna 

 Palaeolithic 2. Lower Breccia, or 'lower rodent' layer, animal remains and traces 



of man, tundra fauna 

 Palaeolithic 1. Diluvial layer. No fossils 



Of these the 'lower rodent' layer (2) contains a pure arctic fauna, such 

 as the vole, hare, fox, the reindeer, the ptarmigan. In the layer above 

 these the early steppe animals begin to appear, the hamsters and picas. 

 Then in the 'yellow culture' layer there is an assemblage of pure steppe 

 forms, susliks, dwarf picas, and wild horses, all pointing to the absence of 

 forests; but at the top of this layer the first squirrel appears as the harbin- 

 ger of forests. In the upper rodent (4) layer the steppe fauna begins to be 

 intermingled with an increasing number of forest types, such as squirrels, dor- 

 mice, and the pine marten. Finally we reach the (5) 'gray culture' layer, 

 composed of the modern forest dwellers, such as the squirrel, the beaver, the 

 pine marten, the stag, the roe, the wild boar, the brown bear. A similar 

 succession of tundra, steppe, and forest faunas has been observed in many 

 parts of central Europe."* 



Elaphine or red deer.* — Sir Victor Brooke held that the Cervidae origi- 

 nated in Asia and from there spread east and west. The Asiatic origin of 

 the red deer has since been ably maintained by Koppen. A very large 

 antlered race has been discovered and identified by Nehring as C. canadensis. 



1 Nehring, A., Ubersicht iiber vierundzwanzig mitteleuropaische Quartar-Faunen. Zcit- 

 echr. Deutsch. Geol. Ges., 1880, pp. 468-509. 



2 Nehring, A., Die kleineren Wirbeltiere vom Schweizersbild bei Schaffhausen. N^eue 

 Denkschr. allg. schweiz. Ges. gesam. Natunciss., Vol. XXV, 1896, pp. 40-77. 



3 Nehring, A., Die kleineren Wirbeltiere vom Schweizersbild bei Schaffhausen. Neue 

 Denkschr. allg. schweiz. Gesell. gesam. Naturwiss., Vol. XXXV, 1896, pp. 40-77. 



< Scharff, R. F., The History of the European Fauna. London, 1899, pp. 246-251. 



