8 SUTCLIFFE, Tendencies in PreJiistoric Anthropology. 



can trace the i^radual , improvement of generations of 

 workmen in the manufacture of an implement by the 

 surface flaking of a flint nodule ; from the Mousterian 

 period upwards we see the evolution of an implement 

 made out of a large rough flake ; in fact, throughout the 

 whole period of flint working we find a definite evolution, 

 sometimes retrogressive, but always such that any series 

 of one age will, without external evidence, suggest its 

 own date. 



The Eolithic flnits have been divided into stages by 

 M. Rutot entirely from the geological evidence of their 

 age, though it is impossible from the internal evidence of 

 a group of Eoliths to give any indication of their terraine. 

 For example, M. Rutot himself determined the stage of 

 some Eoliths found by L'Abbc Breuil in the Thanetian 

 or basal Eocene as Reutelian, a Lower Pleistocene stage. 

 Eoliths, in fact, show no evolution, a fact readily explic- 

 able if they are produced by non-living agents, but 

 beyond explanation if they are products of inan's handi- 

 craft, since human products, as is well shown b\- Pak-eo- 

 lithic implements, invariably show a progressive change 

 in form, usually forward in the direction of greater finish 

 and usefulness, sometimes retrogressive, leading to loss 

 of beauty and degraded types. It is essential for reliable 

 evidence of this character that the worked flints depended 

 on should be ca[)able of being produced by human 

 agencies alone. As most Eoliths are of similar t}pes, it 

 is sufficient to show that those types can be produce'.! by 

 accidental causes, not involving design, to destroy the 

 importance of Eoliths as evidence, although it will still 

 remain probable that some of these flints have actually 

 been used by man. (For exami)lc, the occurrence of 

 Homo heidelbergensis in beds Hitle if any younger than 

 the sands of St. Prest and the Norfolk Forest bed 



