292 Deposits containing Flint Implements. [July, 
contemporaneity is of any value, the occupation of the caves 
by palaeolithic man ceased at the same time as the great 
mammals disappeared. 
Let us look at the question from another point of view. 
In the south of England the remains of the mammoth are 
abundant in the valley gravels. They are found mixed 
through them or more commonly at their base. Palaeolithic 
implements are found in the same position, though usually 
in gravel higher up on the slopes of the valleys. When 
found in the gravel, the bones are broken and worn, and the 
flint implements have their angles rounded more or less as if 
by rolling. When, as has happened in a few cases, the 
bones and implements have been found below the gravels, 
they have been uninjured and unworn. Mr. Godwin Austen 
noticed the occurrence of bones of the mammoth in an old 
forest bed beneath the valley gravels, at Peasemarsh, in 
Surrey, uninjured and lying together, whilst in the over- 
lying gravel, the teeth of the mammoth were found singly and 
rolled.* And Colonel Lane Fox has recorded the discovery 
of flint implements at Addon in seams of white sand, 9 feet 
from the surface, beneath deposits of gravel and brick-earth, t 
Their edges were as sharp as if just flaked off a core of 
flint, whilst those found in the gravel, on the contrary, have 
their edges worn and rounded just like those of the sub- 
angular pebbles of which the gravel is principally composed. 
The position and the state of preservation of the bones 
and implements are such as might be expedted if they had 
been deposited on an old land surface before the outspread 
of the gravels, when the configuration of the country was 
much the same as now ; and I have suggested that the 
occurrence of the implements, generally higher up the 
slopes of the valleys than the mammalian remains, is 
due to palaeolithic man having frequented more elevated 
and drier localities than the great mammals. I have 
urged that the outspread of the gravels was due, as 
formerly supposed by Sedgewick, De la Beche, and Murchi- 
son, to the adtion of a great flood or debacle. I have 
advanced the theory that that debacle was caused by the 
breaking away of a barrier of ice that blocked up the English 
Channel, and with it all the drainage of Northern Europe, 
causing an immense lake of fresh or brackish water that 
was thus suddenly and tumultuously discharged.]: 
* Quart. Journ. Geol. Soc<>, vol. vii., p. 2S8. 
f Ibid., vol. xxviii., p. 456. 
+ Quarterly Journal of Science, April, 1873. Quart. Journ. Geol. Soc. 9 
vol. xxxii., p. 84. 
