32 Dr. J. Croll on Arctic 
away to the north, in the islands of New Siberia, beyond the 
reach of the currents of the small rivers, whose mouths are 
opposite those islands.’’ But a more convincing proof is that 
“they are found not only in North Central Siberia, where 
the main arteries of the country flow, but in great numbers 
east of the river Lena, in the vast peninsula of the Chukchi, 
in the country of the Yukagirs, and in Kamtskatka, where 
there are no rivers down which they could have floated from 
more temperate regions.” Besides, it is not merely in the 
deltas and banks of rivers that the remains are found, but in 
nearly all parts of the open tundra; and Wrangell says* that 
the best as well as the greatest number of remains are found 
at a certain depth below the surface in clay-hills, and more in 
those of some elevation than along the low coast or in the flat 
tundra. 
Had the Mammoth lived in the south we should, as Mr. 
Howorth further remarks, have found its remains most 
abundant in the south, whereas the further north we go the 
remains become more abundant, and in the islands of the 
Liachof archipelago, in about latitude 74°, the greatest 
quantities have been discovered. Again, according to Heden- 
strom, the bones and tusks found in the north are not so large 
and heavy as those in the south; a fact which still further 
confirms the opinion that the Mammoth lived where his 
remains are found, inasmuch as the greater severity of the 
climate in northern parts would certainly hinder the growth 
and full development of the animal. 
Northern Siberia much Warmer during the Mammoth 
Epoch than now.—It is true that the Mammoth and the 
Rhinoceros tichorhinus were furnished with a woolly covering 
which would protect them from cold; but it is nevertheless 
highly improbable that they could have endured a climate so 
severe as that of Northern Siberia at the present day, where 
the ground is covered with snow for nine months in the year 
and the temperature is seldom much above zero Fahr. And 
even if they could have endured the cold, they would have 
starved for want of food. Some parts of Siberia are no doubt 
fertile, as, for example, the valley of the Yenisei, described 
by Nordenskjoldf ; but there is little doubt, as Mr. Howorth 
remarks, that the larger portion of Northern Siberia, where 
the Mammoth and the Rhinoceros lived, is now a naked 
tundra covered with moss, on which no tree will grow. On 
such ground it is physically impossible that the Mammoth 
and Rhinoceros could exist, for they cannot graze close to 
* ‘Polar Sea Expedition,’ English translation, p. 275. 
+ ‘Nature,’ Dec. 2, 1875. 
