FOSSIL MAMMALIA. 393 



" The only detritus in which grains and portions of CHAPTEB 

 gold and platinum have been found, is, in truth, that in ^^^Vlll. 

 which remains of mammoths and rhinoceroses have also 

 been detected ; and coupling this last fact with the 

 omission of all auriferous veins in the more ancient allu- Auriferous 

 via of the chain, there can be no doubt that in this ^''^"^^■ 

 region gold was one of the most recent mineral produc- 

 tions anterior to the historic era. The very nature and 

 form of the ground in which the auriferous debris have 

 been heaped up, shows, that unlike the ancient or Per- 

 mian detritus; this took up its position when the pre- 

 sent configuration had, to a great extent, been brought 

 about, and when valleys existed, in which large quadru- 

 peds, closely allied to those which now live among us, 

 were entombed. We believe, then, that before the sur- 

 face assumed its present outline, the tract we now call 

 the Ural mountains was a low ridge, extending from 

 north to south, and forming the western shore of a con- 

 tinent on which such animals lived and died during 

 long ages." 



Into the very interesting inquiries relating to the Jiammoth 

 habitat of the mammoth, and the valuable discussions 

 by which men of science have sought to clear up the 

 mystery pertaining to this extinct species, it is not 

 necessary to enter at any very great length. In 1829, 

 the valuable gold mines of Peshanka, near Bogoslofsk, 

 were discovered, and have since been wrought with great 

 success. In the same auriferous district, the bones of Ossiferous 

 the mammoth, the rhinoceros, and boss urus, have been 

 found in great abundance in the clay which overlies the 

 gravel, and also in the gold detritus. Cuvier, and other 

 distinguished men of science, who have investigated this 

 subject, have advocated the opinion that the mammoth 

 was the native of a warm climate, and became extinct 

 by some sudden change, which entirely altered the 

 temperature of the regions of their habitat, preserving 

 them therebj', in some cases embedded in masses of ice, 

 in a perfect and entire state. This idea is now, however, 



