202 THE FOREST LANDS OF NORTHERN RUSSIA. 
devoid of all indications of life. With the strata super- 
imposed upon them it is otherwise, and at this point 
the subject is taken up by Count Saporta in the paper 
cited. 
Above the azoic strata are superimposed the Silurian, a 
designation originating with Sir Roderick Murchison, 
derived from St/ures, the name of an ancient tribe which 
inhabited a district of country between England and 
Wales, in which the rocks so designated are very distinctly 
developed, but a deposit which is very widely diffused ; 
the Devonian, so named because it happens to be very 
extensively preserved in Devonshire, but which also is 
very widely diffused, and is known also as the Old Red 
Sandstone, in contradistinction to a later formation desig- 
nated the New Red Sandstone; the mountain limestone, 
so called in contradistinction to cretaceous and chalk 
deposits of a later date ; and carboniferous strata, otherwise 
known as the voal measures, which are generally found 
superimposed upon, but sometimes alternating with, 
deposits of the mountain limestone. 
In reference to the great extent of azoic strata, gneiss, 
and crystalline schists, during the deposit of which the 
water still covered extensively the earth, Count Saporta 
alleges that the ocean did not then present conditions 
requisite for the support of animated structures even of the 
lowest order ; that 1t must have been only in the sea, when 
reduced to a temperature which, though still high, would 
not coagulate albumen, that such could be expected to 
appear; that this appearance would occur in basins com- 
paratively calm, suitable for the development and subse- 
quent maintenance of such organisms; that there is 
nothing known at variance with the supposition of Buffon 
that this must have occurred first in proximity to the 
Pole; and, moreover, that there terrestrial vegetation first 
appeared, when vegetation first ceased to be exclusively 
aquatic, and appeared on land still immersed in vapours, 
and bathed by the tidal wave; and he goes on to say :— 
‘In these the earliest formations must have been humble 
