1878.] Superficial Gravels and Clays. 353 
The significance of these facets is entirely lost if we have to 
suppose that the configuration of the prediluvial land was 
not the same as it is now. 
D. Lower Diluvium . — During the last stage I suppose 
that the Atlantic ice had slowly progressed southward, the 
climate of the temperate zone becoming every year more 
vigorous in consequence. In those last days of palaeolithic 
man the reindeer lived the whole year through in Southern 
France, and the musk sheep reached in its migrations the 
same low latitude. 
The readers of this journal who have followed me in my 
former papers will recoiled! that I have already given some 
explanation of the cause of the accumulation and of the 
mode of advance of the Atlantic ice. I feel, however, 
that I have not dealt with this important phase of the 
question with the fulness it deserves as lying at the very 
foundation of the theory. I must ask my readers to bear 
with me whilst I speak of this advance of the Atlantic ice 
as a fad!, fully recognising my obligation in so doing to 
address myself at the first opportunity to the solution of the 
physical difficulties of the problem. They evidently weigh 
heavily with many scientific authorities without being 
ad!ually defined. They are indeed more fanciful than real, 
more a failure of the imagination to conceive a state of 
things so different from that now existing than any clearly 
perceived objedtion ; but reason has a stronger pinion and a 
more piercing eye than imagination, and leads the way to 
regions that would remain unknown to her sister excepting 
for her guidance. 
I suppose that the Atlantic ice at last reached the 
Pyrenees, or coalesced with the ice flowing from that moun- 
tain-chain, closing the outlet of the northern drainage of 
the Continent to the Atlantic. The gap between the 
western Alps and the eastern Pyrenees was also filled 
with ice, and Behring’s Straits similarly closed. The com- 
munication between the Black Sea and the Mediterranean 
not having yet been cut through, the waters began to rise 
over all the northern parts of Asia and Europe. The bulky 
mammoths and rhinoceroses frequenting the low plains 
would probably be the first to be overwhelmed. Some might 
find a temporary refuge on low isolated hills only to be 
overtaken by the rising water. The higher ranges of hills 
would form the chief places of refuge, but many of these, 
especially in western Europe, were covered with ice. The 
Altai mountains in Central Asia, the Urals, the Caucasus, 
VOL. VIII. (n.s.) 2 A 
