10 
gutters or lines of weakness of the chalk, and partially filled 
by hard rubble from the eroded materials. Then there was, 
first, a short occupation by man, and afterwards a recurrence of 
eroding action, accompanied by a considerable elevation of the 
land, and next a lowering or a flow of the sea into the ends of 
the old depressions first opened to its action by these move- 
ments. The waters still were larger than at present, making 
huge deposits of clay, mud, and sand; but by a rise of the 
land — gradual, though not continuous, — the rivers became re- 
duced to present dimensions, present levels w r ere fixed, and 
man resumed his occupation and remained as a dweller. 
(3.) I will now advert more specifically to the fact already 
alluded to, — the violent disturbance in the framework of Europe 
that took place before the historical period, before the neolithic 
period, closing, probably, the paleolithic age of man's occu- 
pation. This disturbance the following witnesses will prove : — 
Sir C. Lyell says : — f ‘ There were probably many oscillations 
of levelduring this last conversion of continuous land into islands.” 
Belgrand, speaking of the level of the Seine, says : — “ 11 y a 
done eu, entre les temps des hauts et des has niveaux, uu 
relevement du continent, peu considerable comme fait geolo- 
gique, ruais suffisant, cependant, pour produire de graves pertur- 
bations dans le regime des eaux, et pour modifier la forme du 
fond de la vallee.” * 
The fractures in the chalk, and contortions of the old drifts 
on the island of Moen, fifty miles south of Copenhagen, prove 
the action of great and frequent oscillations and disturbances 
since the older pleistocene beds w r ere deposited, although these 
dislocations usually leave but slender traces in gravel-beds. 
Professor Daw r son adds : — “ This seems to have been a com- 
paratively rapid subsidence and re-elevation, leaving but slender 
traces of its occurrence, but changing to some extent the levels 
of the continents, and failing to restore them fully to their 
former elevation, so that large areas of the lower grounds still 
remained under the sea.” f After considering the effect of 
crust movements in the earth as bearing upon the question, he 
adds : — “ There is, therefore, nothing unreasonable in that view 
which makes the subsidence and re-elevation at the close of the 
post-glacial period somewhat abrupt, at least when compared 
with more ancient movements.” J 
We have then the undoubted fact that the mammoth age 
was characterized by at least one period of terrestrial disturb- 
ance, by which the land and water w r ere greatly modified in 
* La Seine, p. 99. 
t lb., p. 290. 
t lb., p. 292. 
