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nient. between inferences by the two methods as to the 
character of the immediate causes of geological phenomena, 
which, as contributing to the completeness of my argument, I 
shall now point out. 
“The Glacial epoch, though for the most part anterior to 
the valley-drifts and cave-deposits of the Palaeolithic age, was 
still so closely connected with that period that we cannot easily 
draw a line of demarcation between them.” (Lyell, Principles 
of Geology, vol. i. p. 192, 11th ed.) “ There were also great 
changes in the form of the earth's crust, many movements of 
upheaval and subsidence, and many conversions of sea into 
land, and land into sea, during the Glacial epoch.” [Ibid., p. 
196.) These statements are reconcilable with our theory 
if it be understood that the Glacial period was synchronous 
with the interval during which the localities which show marks 
of glacier-action were much more elevated than they are at 
present, and that it extended to the epoch of the oscillatory 
movements (mentioned in the above extract), which issued in 
bringing those localities to their present level. The period of 
the valley-drifts and deposits was closely connected with this 
Glacial period as constituting the termination of it, for which 
reason also no definite line of demarcation can be drawn 
between them. 
“ In Wales the rocks had been exposed to glacial polishing 
and friction before they sank.” “The evidence of the sojourn 
of the Welsh mountains beneath the waters of the sea is not 
deficient in that complete demonstration which the presence of 
marine shells affords.” (Antiq. of Man, p. 313.) Such submer- 
gence might be produced by the first oscillatory movement, 
which, according to the theory, would be downward. Marine 
shells have been discovered “ in North Wales, in drift elevated 
more than 1,300 feet above the level of the sea.” (Ibid., p. 313.) 
“ Professor Ramsay infers, from the position of the stratified 
drifts of the Glacial period in North Wales, that the full extent 
of the vertical movement which brought about first the sub- 
mergence, and then the re-emergence of the land, exceeded 2,000 
feet.” ( Principles of Geology, vol. i. p. 193.) 
Referring to geological observations made by Professor Geikie 
in Scotland, Lyell speaks of them as “requiring for their 
explanation several oscillations of level and successive submer- 
gences and re-elevations of the land.” (Antiq. of Man, p. 295.) 
“There can be no doubt that the physical geography of 
Europe has changed wonderfully since the bones of men and 
mammoths, hyaenas and rhinoceroses, were washed pell-mell 
into the cave of Engis.” (Huxley, Man’s Place in Nature, p. 1 20.) 
