1898] A UTHENTICITY OF PL A TEA U IMPLEMENTS 1 1 



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those found upon bard stones from glaciated districts. I have 

 considerably over a hundredweight of glacially striated flints and 

 implements ; these are often upon blocks off which several parallel 

 flakes, five or six inches long, have been flaked, sometimes over 

 bulbed flakes, six to eight inches long, and sometimes upon well- 

 made implements. So that, while the striations show that the 

 flaked surfaces antedate the conditions to which the implements 

 have been subjected, they do not in any way militate against the 

 human origin of striated worked flints. 



As to the action of blown sand. While such a process would 

 have no weight either one way or the other in connection with the 

 authenticity of plateau man, may I ask Mr Cunnington if he is not 

 confotinding this with patination ? A closer study of desert pebbles 

 and the Dewlish gravels might perhaps convince him that this 

 is the case. We thus see that these postulated conditions have 

 either no existence at all, or have nothing to do with the authen- 

 ticity of plateau man. 



Mr Cunnington next attacks the chippings which brought the 

 flints into their present shape and condition. Unfortunately, in 

 his descriptions he is a little ambiguous, and, so as to prevent 

 myself falling into the same error, perhaps I may be allowed to 

 define the sense in which I employ similar words to those used by 

 my esteemed fellow-worker. By a flake I mean a piece of flint 

 removed from a block by a free blow or percussion, moving or 

 applied in a given direction. The place of actual contact of the 

 power will be marked by a distinct point, which upon the flake is 

 known as the bulb of percussion, and upon the block as the pit of 

 percussion. Around this point a series of waves or ripplings may be 

 observed, the shape and direction of which are subject to mathe- 

 matical laws and the homogeneity of the ' flaked ' substance. T 

 may say that, given any two of these quantities, the third can be 

 obtained mathematically. Such being the case, we have often — 

 though by no means always — a crucial test for man's work. The 

 so-called frost pits arise in another way altogether ; the action 

 has many points in common with perlitic structure, but is too long 

 a subject to digress into here. I have a collection of flints pitted 

 into the shape of practically every type of implement. In other 

 cases paleoliths are often pitted away, until only here and there 

 are left traces of man's flaking. Without entering into further de- 

 scriptions, we may say that in a frost pit or a ' pot lid ' there is no 

 pit or bulb of percussion. Depending upon the unaltered and homo- 

 geneous conditions of the flints, there are well-marked conchoidal rip- 

 plings, not so uniform as those produced from a blow, often extremely 

 excentric, but they originate at a point seen on the base of the pit, 

 and not at the periphery of the flint, where a little single or double 



