460 Notices of Memoirs — 



more rainy climate prevailed. We had proofs of the occupation 

 of the country by man during the long lapse of time that was 

 necessary for the excavation of the river valleys. We had found 

 the old floors on which his habitations were fixed, we had been able 

 to trace him at work on the manufacture of flint instruments, and 

 by building up, the one upon the other, the flakes struck off by 

 the primaeval workmen in those remote times we had been able 

 to reconstruct the blocks of flint w^hich served as his material. 



That the duration of the Palasolithic Period must have extended 

 over an almost incredible length of time, was sufficiently proved 

 by the fact that valleys, some miles in width and of a depth of from 

 100 to 150 feet, had been eroded since the deposit of the earliest 

 implement-bearing beds. Nor was the apparent duration of this 

 period diminished by the consideration that the floods which 

 hollowed out the valleys were not in all probability of such frequent 

 occurrence as to teach Paleolithic man by experience the danger 

 of settling so near to the streams, for had he kept to the higher 

 slopes of the valley there would have been but little chance of his 

 implements having so constantly formed constituent parts of the 

 gravels deposited by the floods. 



The examination of British cave-deposits as at Kent's Cavern, 

 Torquay, aflforded corroborative evidence of this extended duration 

 of the Pala3olithic Period. 



In a cavern at Creswell Crags, on the confines of Derbyshire 

 and Nottinghamshire, a bone had been found engraved with 

 a representation of parts of a horse in precisely the same style 

 as the engraved bones of the French caves. 



It was imcertain whether any of the river-drift specimens 

 belonged to so late a date as these artistic cavern-remains ; but 

 the greatly superior antiquity of even these to any Neolithic relics 

 was testified by the thick layer of stalagmite, which had been 

 deposited in Kent's Cavern before its occupation by men of the 

 Neolithic and Bronze Periods. 



Towards the close of the period covered by the human occupation 

 of the French caves, there seemed to have been a dwindling iu 

 the number of the larger animals constituting the Quaternary 

 fauna, whereas their remains were present in abundance in the 

 lower and therefore more recent of the valley gravels. This 

 circumstance might afford an argument in favour of regarding the 

 period represented by the later French caves as a continuation 

 of that during which the old river gravels were deposited ; and 

 yet the great change in the fauna that had taken place since 

 the latest of the cave-deposits included in the Paleolithic Period was 

 indicative of an immense lapse of time. 



We found distinct traces of river-action from 100 to 200 feet 

 above the level of existing streams and rivers, and sometimes 

 at a great distance from them ; we observed old fresh-water deposits 

 on the slopes of valleys several miles in width; we found that 



