405 
flints derived from the underlying beds of that formation, some of the 
siliceous fragments of which have been transported further south- 
wards, and spread over the regions occupied by the newer red and 
oolitic. deposits. \ Thus, ‘as all the larger and harder blocks can be 
Shown to have been carried from the mountains on the N.N.W., so 
in passing to the S.S.E. the finer ingredients, or matrix of the de- 
tritus, is found. to change by the successive additions of materials 
derived. from the denudation of the different members of the pake- 
ozoic series. There is no instance of any substance having been 
transported from S. to N., except by the modern action of streams, 
and by local. causes dependent on the present configuration of the 
land. Near Nijnii Novogorod large blocks of a very peculiar trap- 
pean conglomerate were detected, which had been derived from a 
rock in situ.N. of Petrazowodsk, a distance of nearly 600 miles. In 
endeavouring to account for the immense distances to which these 
blocks had been transported, the authors expressed 1 their belief that 
they, had been floated in former icebergs, which breaking loose from 
ancient glaciers; which they suppose may have existed in Lapland and 
the adjacent tracts, were dislodged upon an elevation of the northern 
chain, and impelled southwards into the sea of that period, in which 
the post pleiocene shells, to which allusion has been made, were ac- 
cumulated. In the relation of the blocks to the sea shells, they, con- 
ceive that. Central. Russia presents an exact parallel (though on a 
much grander scale) to the phenomena described by one of the au- 
thors in the central counties of England, where a similar collocation 
was accounted for, by supposing that the northern blocks were borne 
thither in vessels of ice, which in melting’ dropped them upon what 
was then a sea bottom*. 
Glacial -Action.—After alluding to the works of Séfstrém and 
Botlingk upon the supposed “ diluvial’’ currents of Scandinavia and 
Lapland, as evidenced. by the parallel strie and polishing of the sur- 
face of the hard rocks of these regions, the authors describe the most 
southerly of, the scratches, which came under their notice near Pe- 
trazowodsk, on the lake Onega, no such markings having anywhere 
been. observed in Central Russia. They then examine the applica- 
bility. of the glacial theory, as proposed by M. Agassiz, to the tracts 
of Russia.under review: Starting from what they conceive to be an 
axiom, that. the advance of every modern glacier depends upon the 
superior altitude of the ground behind it, they show, that if certain 
parallel strie, observed by M. Bétlingk, and others noted by them- 
selyes, are to be taken as proofs of the overland march of glaciers, 
such bodies must often have been propelled from lower to higher 
leyels... For the proofs of this they refer to the eastern sides of the 
Bothnian Gulf, where M. Botlingk found the striz (“‘ diluvial schram- 
men’) directed in common with the boulders from N.W. to S.E.; 
and yet any glaciers which bore these blocks must have advanced 
from Scandinavia, across the Baltic Sea, and then have ascended 
the rocky tract in question. - Again, near Petrazowodsk, in the isles 
‘ * Silurian System, Pp. 535, et seq. 
VOL. INI. PART II, 21 
