102 POPULAR SCIENCE MONTHLY. 



the deposit of the earliest implement-bearing beds. Nor is the ap- 

 parent 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 palaeolithic man by experi- 

 ence the danger of settling too 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 affords corroborative 

 evidence of this extended duration of the palaeolithic period. In 

 Kent's Cavern at Torquay, for instance, we find in the lowest de- 

 posit, the breccia below the red cave earth, implements of flint and 

 chert corresponding in all respects with those of the high level and 

 most ancient river gravels. In the cave earth these are scarcer, 

 though implements occur which also have their analogues in the 

 river deposits; but, what is more remarkable, harpoons of reindeer's 

 horn and needles of bone are present, identical in form and charac- 

 ter with those of the caverns of the reindeer period in the south of 

 France, and suggestive of some bond of union or identity of descent 

 between the early troglodytes, whose habitations were geographically 

 so widely separated the one from the other. 



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

 Nottinghamshire, a bone has, moreover, 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 is uncertain whether any 

 of the river-drift specimens belong to so late a date as these artistic 

 cavern remains; but the greatly superior antiquity of even these 

 to any neolithic relics is 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. Toward the close of 

 the period covered by the human occupation of the French caves 

 there seems to have been a dwindling in the number of the larger 

 animals constituting the Quaternary fauna, whereas their remains 

 are present in abundance in the lower and therefore more recent of 

 the valley gravels. This circumstance may afford an argument in 

 favor 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 has taken place 

 since the latest of the cave deposits included in the palaeolithic 

 period is indicative of an immense lapse of time. How much 

 greater must have been the time required for the more conspicuous 

 change between the old Quaternary fauna of the river gravels and 

 that characteristic of the neolithic period! As has been pointed out 

 by Prof. Boyd Dawkins, only thirty-one out of the forty-eight well- 



