360 
some exceptional flood, is a question about which a field geologist can gene- 
rally form a good opinion. 
Prof. Huxley’s remarks, quoted in a footnote on p. 342, refer to the effect 
•which such changes might have on the rate of denudation, but do not call 
in question the fact that the valley has in the main been scooped out by the 
river. 
Of course many mistakes have been made, as might have been expected, 
where so many people with very various previous experience of such pheno- 
mena have been examining the gravels and loams for evidence of the 
existence of man during the period of their deposition. What we have to 
ask is, are there any well-authenticated cases ? — and I think we must admit 
that there are. 
Prof. Boyd Dawkins’ note, referring as it does to several cases which I 
have not had an opportunity of examining, usefully supplements and supports 
the arguments I have adduced. 
Mr. Harrison will find recorded plenty of instances of the large mammalia 
in northern regions being caught by river floods, or in the ice, and perishing 
in herds. Although this may occur only now and then, it is part of the 
ordinary operations of nature there. When I said they went out one by one, 
I was not referring to individuals, but to species (races and groups). To 
follow the theories propounded by Mr. Harrison would lead me too far from 
the points I proposed to deal with in my paper. 
Mr. Mello raises some interesting questions, which I fear cannot at present 
be answered, among them the reason of the gap between the Paleolithic and 
Neolithic periods. There are some things which lead one to infer that the 
Paleolithic type, though it went back very far, also came down to Neolithic 
times ; as, for instance, the occurrence of so many Paleolithicjforms among 
the misfits of Grime’s graves near Brandon, in Suffolk, and the Paleolithic 
implements scattered over the surface at La Ganterie, near Dinan, in 
Brittany. 
Mr. Pattison would find among the causes now in operation full expla- 
nations of floods and debacles sufficient to fill many a valley with coarse 
debris. When a flood dammed for a time some of the upper waters of the 
Rhone, and then they broke loose upon the valley, filling it, as I myself saw, 
with rocks and stone ; when a thunder-storm had burst upon a small hill- 
side in Westmoreland, and I saw the greater part of a field covered in two 
hours with gravel 10 feet deep, — all this was but the common way of rain and 
river denudation. But we know that kind of debris when w% see it, and it 
is not in that kind of gravel that the implements I referred to were found, 
still less in a gravel showing any evidence of having been transported by 
great rushes of water due to violent earth-movements. 
I regret that the Member writing from Cirencester lias been unable to find 
evidence in that district to satisfy him as to the mode of formation of the 
Thames and other similar valleys, but I doubt not that the views I have 
put forward on this point will on further inquiry bo moro generally admitted. 
