426 Sir R. I. Murchison on the 



state, whilst the superposition of the clay to the shingle is best ex- 

 plained on the hypothesis of formation, under lacustrine or broad 

 fluviatile conditions, which eventually assumed a tranquil character. 

 Such, in fact, are precisely the cases of the great valleys of the Rhine 

 and the Danube ; and just as we have imagined that the mammoth 

 lived in those Uralian tracts, when the adjacent parts of Siberia were 

 occupied by lakes, so do we suppose that the like animals, whose 

 bones are found, both in the coarse shingle of the Rhine, and in the 

 overlying loss near Baden-Baden, once lived upon the grounds which 

 now constitute the Black Forest, and adjacent alpine tracts, whence 

 the detritus has been derived. With evidences of internal lakes and 

 ancient rivers, in which the bones of some of its ancient quadrupeds 

 were lodged, Great Britain, though evidently also the abode of 

 mammoths, is distinguished from the Ural and Siberia, in exhibiting 

 around its coasts, and even far into the interior, the proofs of the 

 abode of the sea or marine estuaries during long periods. 



But we now return to the Ural. A former terrestrial surface on 

 which the great quadrupeds lived for long ages, and the rupture and 

 desiccation of adjacent lakes, coincident with some of the last eleva- 

 tions of the chain, will, we are convinced, best explain the condition 

 in which the remains of the mammoths are left buried on the edges 

 of the uplifted ridges of the Ural, as well as in the low lands and 

 great estuaries farthest removed from them. In the depressions jat 

 the very foot of the chain, the mammoth skeletons are broken up, 

 and their bones, together with those of Rhinoceros tichorhinus and 

 Bos Urus, are rudely commingled in the coarse shingle derived from 

 the mountains, or in the clay above it. In proportion, however, as 

 we advance into the plains of Siberia, or descend into the valley of 

 the Tobol and the Obe, or their affluents, these bones increase in 

 quantity, and are at the same time in much better conservation. 

 Even in the flat country of Siberia, about thirty versts eastward of 

 our excursion on the Issetz (see p. 366), Pallas mentions the occur- 

 rence of teeth, vertebrae, and bones of mammoth, and remains of 

 fossil ox, as having been found abundantly by the peasants at several 

 localities near Tamakulsk, and the source and banks of the little 

 streams Atish Suvarish, both tributaries of the Issetz. He also 

 gives (from the information he received) a detailed account of the 



