679 
class observed by him in Finland, and he shows that there the 
blocks and striz proceed from N.N.W. to S.S.E. 
The theory of Sefstrom and his followers is, thaf a great flood, 
transporting gravel, sand and boulders, was impelled from the 
north over pre-existing land, and that the deviations from the N. 
and 8. direction are due only to various promontories by which 
the flood was deflected. .So convinced was this author that with 
local aberrations all the transport throughout the whole of Europe 
had taken place from north to south, that he not only travelled over 
the whole of Germany and saw nothing except materials streaming 
in the same direction, but even carried with him his northern drift 
into the Austrian and Bavarian Alps. I will not waste your 
time by pointing out the errors into which his hypothesis, though 
founded on data good within a limited radius, led this author. 
Every one who has studied the Alps (and the facts were well known 
before the days of glacial theories), is perfectly aware that the de- 
tritus on their flanks has been shot off eccentrically from the higher 
central masses. The observations indeed of Béhtlingk give the same 
result upon a very grand scale in the North, and explain what 
Sefstrém, with all his valuable labour, had left unknown, viz. that 
the Scandinavian mountains, as a whole, had produced exactly the 
same detrital result as the Alps, having poured off their detritus in 
all directions from a common centre, the northern chain differing only 
from that of central Europe by the much wider range to which its 
blocks and boulders were transmitted. 
My own belief, Gentlemen, as you know, has been, that by far 
the greatest quantity of boulders, gravel, and clay distributed over 
our plains and occupying the sides of our estuaries and river 
banks, was accumulated beneath the waters of former days. ‘Through- 
out large tracts of England we can demonstrate this to have been 
the case by the collocation of marine shells of existing species with 
far-transported materials. It was the association of these testacea 
with foreign blocks in the central counties of England which first 
led me to attach a new and substantial value to that view of glacial 
action which had been so well advocated by Mr. Lyell before Pro- 
fessor Agassiz came forward with his great terrestrial and general 
theory. I am bound to say that wide researches during the last two 
years havé strongly confirmed my early views*. I could not travel 
in the autumn of the year 1840 around the shores of the highlands 
of Scotland, without being convinced that the terrace upon terrace, 
presented on the sides of some of the great valleys, and often high 
upon the sea-ward hills of the bays opening out to the ocean, were 
nothing more than the bottoms of former seas and estuaries which 
had been successively desiccated. 
I coincide, therefore, entirely with Mr. C. Darwin in his very in- 
genious explanation of the probable formation of the parallel roads 
of Glen Roy (Phil. Trans., 1839, p. 39). Since then that excellent 
observer has borne out similar views in a paper read before our 
* See Silurian System, p. 536. 
