464 
Prof. Milne — Across Europe and Asia. 
times, no deposit kad been formed. On the evening of tke 5tk, it 
was warm enough to go outside without an overcoat ; but next 
morning, as we sigkted Tomsk, it was bitterly cold, and our decks 
were tbickly covered witk ice. The time at whick tke Tom generally 
becomes fi-ozen is about the 22nd of October, and it tken remains 
closed until about tke 20th of April. 
Before proceeding witk a description of tke country whick I saw 
beyond Tomsk, I will give my impressions of tke vast plain tkrough 
wkich, since leaving Turnen, I kad been traversing. One great 
feature was tke absence of variety, in consequence of wkich my 
daily observations became almost a series of identities, — everywkere 
there was one great plain composed of eitker sand or loam forming 
more or less of an open Steppe. 
The origin of tkese Steppes, according to Mr. Thomas Belt and 
Siberian geologists, was due to tke blocking up of the moutks of 
tke great Siberian rivers by an overflow of polar ice from tke north, 
and a consequent flooding of tke country by an overflow of tke 
rivers in the soutk. Mr. Belt chiefly bases this view on observations 
made by bim when on a journey from Ekaterinburg to Byanovl, 
360 miles S.E. from Omsk. 
One Observation which was apparently very quickly made was, 
“ tkat tke plains kad no relation to tke present river-system ; tke 
rivers simply cut tkrough thern ; and there are no defined river- 
basins bounded by roclcs of greater age on whick tkey migkt kave 
been deposited.” 
Tkis simple but grand metkod of dealing witk the river-systems 
of Northern Asia and tkeir boundaries, whick are but little better 
explored tkan tke sources of the Nile, is not, I think, in all senses 
justifiable ; for if we take any Physical Map of Asia, we skall see 
tkat tke river-systems form a remarkable example of the connexion 
of rivers and plains, whick can be only paralleled on tke Amazons. 
Wkerever there is a river, and especially a large one, a broad 
plain accompanies it for tke greater portion of its course. As it 
expands in flowing north, the plain also expands. The widening of 
tkese plains continues until tkey touch eack otker, wlien tkey uuite 
to form tkat open flat expanse whick fringes tke Arctic Ocean. 
Tkat every river kas a tongue of flat ground tkrough whick it 
runs is a fact whick points to tke intimate connexion of the two 
(plain and river). Such a fact as tkis assists in making Mr. Belt’s 
argument more comprekensible ; for, instead of being led to regard 
tke whole of Northern Siberia as having been one huge freshwater 
lake, tke area of whick would be unparalleled, it migkt now be 
regarded as several areas, eack occupying more or less its own 
particular basin. 
The most important point about tkese plains is tke immense 
expanse of sand and loam whick tkey everywkere exkibit. Tke 
absence of marine shells and tke presence of freshwater skells like 
Cyrena ßuminalis over a great portion of tke area furnish strong 
evidence, whick Mr. Belt brought forward in Support of bis argu- 
ment, that tkese strata were deposited in fresk rather tkan in salt 
