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a great gap did separate that lower deposit from the upper. He says it is 
difficult to correlate the ages of the cave deposits with the gravel, and in that 
I agree with him ; but if the fauna of the caves containing hyaenas is in any 
way comparable with the fauna of the river gravels containing implements, 
how much older must be the fauna of Kent’s Cavern containing bears and 
rough implements ? 
Professor Hughes.— I must apologise that owing to pressure of work 
and to my being called off unexpectedly, I was unable to send in my paper 
in time to have it printed before the meeting. The discussion has covered 
a very wide field, a wider field than I had anticipated would have to be 
traversed, so that I must go quickly over the notes I have taken. The first 
speaker talked principally about the Thames district, and brought examples 
from London of Roman remains which have been found over the deposits to 
which I have called attention. But I fail to see how these Roman remains 
bear upon the question I was dealing with. The Roman remains were dropped 
on the surface and buried in the ground, and still more recent things have 
been found nearer the surface. What I stated was that the formation in which 
the mammoth and man were found was an alluvial deposit which must have 
been left by a river behaving as rivers usually do. All the earlier speakers 
laid great stress on the fact that in the Thames valley near London the 
river is not doing any work of excavation at the present time. With that I 
entirely agree, and one of my chief arguments is founded on it . The Thames 
in the lower part of its course deposits what it got from higher ground ; for 
the denudation we must go higher up the valley. 
Mr. J. E. Howard. — The mammoth remains show no denudation since 
that period. The Thames has not cut down the valley since the time the 
mammoth inhabited the district. 
Professor Hughes. — [Professor Hughes described on the black-board 
the mode in which he asserted the denudation to have taken place.] He 
continued, — I was glad to hear that all the speakers allowed a long 
time to have been required to form the valley at the present rate of 
waste ; but the point which has been lost sight of is the denudation 
which takes place at the rapids and waterfalls, and though, as has been 
mentioned by one speaker, the river bed of the Somme at the period of the 
deposition of the flint-implement-bearing gravels may have fallen at the rate 
of 2 ft. in a mile, even that would admit of rapid denudation if the fall were 
not uniform along the whole length. The denudation would go on at the 
rapids where the valley was being cut back (not cut down) and in the lower 
reaches below the falls and rapids there would be no excavation going on. 
Earthquakes might modify the conditions by producing fissures, but we 
ought to go and examine the ground in each case and see whether there is any 
evidence of such cracks. I have noticed how the rate of waste would be 
affected by upheaval and depression, but we have no evidence in these cases 
of exceptional or cataclysmic action. If there had been such we should see 
masses of stone and coarse material carried to points where the velocity of 
the water was checked. But I ask you to look at the sand and gravel and 
