92 SCIENCE PROGRESS 



late St. Acheul date, and it is surprising therefore to find it 

 quoted as proving anything about the age of the Chellean period; 

 especially . as M. Rutot, 1 and apparently M. Commont 2 too, 

 place the Rissian glaciation between the Chellean and Acheu- 

 lean industries. 



The same may be said of the Warren Hill gravels, in which 

 both Chellean and Acheulean implements occur, often abraded, 

 and giving other signs of derivation. Dr. Allen Sturge himself, 

 on whose paper Mr. Dewey relies, regards them as later than 

 those of Swanscombe, and so far from their overlying the 

 Chalky Boulder Clay, as Mr. Dewey states, proofs are given 

 that that formation has been pushed against and into the gravels 

 since their deposition. 



Lastly there is the evidence of the Hornchurch section, in 

 which gravel was seen lying on Chalky Boulder Clay at the 

 level of the ioo ft. terrace, but no implements were found in 

 it, and there is no evidence at all to show that it may not be 

 the equivalent of the upper gravel at Swanscombe, which is 

 admittedly post-Acheulean, and not a river deposit at all. 



All these sections then are unsatisfactory, but greater 

 weight perhaps attaches to the fact that so acute and pains- 

 taking an observer as Mr. Reid Moir has failed to find in the 

 Middle Glacial gravels at Ipswich any industry but a pre-palaeo- 

 lithic one ; but more of this negative evidence is required in 

 view of the fact that in some regions {e.g. Rickmansworth) no 

 line of demarcation can be drawn between the Middle Glacial 

 and the Palaeolithic gravels. 



Of the many problems arising out of the geological position 

 of the early palaeoliths indicated in the preceding pages, 

 none is of greater importance, or more peculiarly a task for 

 British geologists, than this of determining the relation of the 

 human industries to the glacial deposits ; and however right 

 the conclusions already arrived at may be, it is unfortunate 

 that they should have been allowed to rest so long on in- 

 sufficient premises. 



II. The Upper Palaeolithic Period 



The Upper and Lower Palaeolithic are often spoken of as , 

 the Cave and the Drift Periods respectively, and this is legit i- 



1 Bull. Soc. Beige de Gdol. vol. xx. (1910), p. 88. 

 3 Les Hommes Contemfiorains, etc., p. 15. 



