1898] THE AUTHJEXTICITY OF PLATEAU MAN 33 



would think of challenging the statement of Sir John Evans " that 

 the rolling and wearing of the edges were probably caused by natural 

 agencies." It is the occurrence and manner of the flakinjj; that is 

 relied on as proof of the human origin of these implements. The 

 old and oft repeated challenge by Sir Joseph Prestwich to the 

 doubters to produce natural Hints having the form of the Plateau 

 specimens has not yet been responded to, and I venture to believe it 

 never will be. 



As to the age of the gravels in which these implements occur 

 the bulk of the evidence is of such a technical character that it 

 would be quite out of place in this paper, but should anyone wish 

 to examine it in detail I would refer him to the papers by Sir 

 Joseph Prestwich. His view that these gravels are of Pre-giacial 

 age has received the support of practically all geologists who are 

 well acquainted with the area. Mr Cunnington holds them to be 

 frozen gravels and therefore glacial, and this view has the support 

 of Mr Clement Keid.^ Mr Eeid arrived at this conclusion after a 

 brief visit to the district, and he would further correlate them with 

 the implement-bearing gravels of Sussex and the Thames Valley. 

 The only sections of the gravel that we know of are from the pits 

 at Parsonage Farm, Ash ; and here it was six to twelve inches in 

 thickness cemented by a ferruginous deposit. Anytliing more unlike 

 a frozen gravel than this I do not know. An undoubted frozen 

 gravel deposit does occur in the area of the Xorth Downs, as was 

 pointed out years ago by Charles Darwin. It is to be found filling 

 up the bottoms of the chalk valleys, and sometimes attains a thick- 

 ness of thirty feet. It consists of unrolled and subangular flints, 

 Tertiary pebbles, and other material, and is without doubt the sweep- 

 ings of the adjoining higher land. Bones of the musk ox, mammoth, 

 and horse have been found in it, as well as land shells. Derived 

 Plateau flints also occur, thus clearly showing that they are anterior 

 in age to this deposit. They also occur as derivatives in both the 

 Thames Valley and the Limpsfield gravels. From its situation the 

 latter has always been held to be of greater antiquity than the 

 former and this view is supported by the character of the contained 

 flint implements. In fact the whole of the available evidence 

 strongly supports the Pre-glacial age of these beds, and none is forth- 

 coming to uphold the opposite view. Mr Pieid suggests that the 

 rude character of the implements arises from the fact that owing to 

 toughening by weathering these flints could only be battered and 

 not flaked, but this ingenious suggestion has been easily disproved 

 by Mr Harrison, who has made from the Plateau flints very good 

 copies of the Eiver-drif t types, one of which is before me as I write ; 

 and he informs me that there is no difficulty in so doing. 



' Annual Report of the Geological Survey of the United Kingdom, 1897, p. 78. 



C 



