J. Croli— Arctic Interglacial Periods. 307 
In Europe is the same as that in which they oceur in Siberia. 
The deposit is a freshwater one, consisting of marly clay and 
shells. When these plants and shells are examined, they are 
found to indicate the same interglacial condition of climate as 
that which prevailed in Siberia during the time the Mammoth 
lived in that regi n. 
_In the case of land-plants it is, of course, only under excep- 
tional circumstances, as Prof. J. Geikie remarks, that they can 
ound in a condition suitable for the botanist. Now and 
formed upon the borders of incrusting springs. An examina- 
tion of the plant-remains found under these conditions shows 
48 more equable and uniform than it is at the present day. 
The Gceaitiferous remains yielded by the tufas have led to . 
* Most important results as to the climatic condition of the Pleisto- 
ste period, into the details of which I need not here enter. 
These will be found at full length in Prof. J. Geikie’s Prehis- 
toric Europe, chap. iv. It will suffice at present simply to 
refer to the general conclusions to which these researches have 
ing at the time the Mammoth lived so abundantly in Europe. 
In the tufa deposits of 
P intxemains of indigenous = 
* Geol. Mag., May, 1881. 
t See ding ha: Hewonh's memoir, Geol. Mag., June, 1881. 
