Stone Implements in lateritic formations. 15 



dually ground down to a smaller size or is split into irre- 

 gularly shaped fragments which in their turn are worn down 

 and rounded at the edges, and in course of time become 

 smaller pebbles themselves, and if the operation be sufficient- 

 ly long continued are perfectly rounded off. 



An angular fragment of any hard rock submitted to such 

 a process of attrition becomes a pebble — i. e, becomes 

 rounded by wear. 



The characteristic feature possessed by all the Implements 

 is that they are shaped to show a cutting edge lying in one 

 plane with reference to the axis of the Implement, and this 

 Without regard whether their shape is oval, discoid, pointed 

 like a spear, or broadly wedge-shaped like a hatchet. In 

 some of various types this edge goes entirely round the Im- 

 plement as in those figured in Plates IV, VI, VII, IX and X ; 

 in others it occurs on three sides and a blunt base is left ; 

 in a third type only two edges exist tapering to a point and 

 with a blunt base — in a fourth three sides though evidently 

 trimmed are obtuse, and the fourth has a sharp cutting edge. 



In those Implements which have themselves been exposed 

 to the action of moving water, the process of conversion into 

 true rounded pebbles is clearly visible. 



Various persons to whom the quart zite Implements have 

 been shown have objected that they bore an air of newness 

 and were not weathered. It suffices to show a freshly 

 chipped surface of the same stone to satisfy any one that 

 this is not the case, but that in most of them a very per- 

 ceptible amount of weathering has taken place and given 

 the surface a genuine appearance of antiquity. 



In many cases the alteration of the stones extends 

 inward from a twelfth to an eighth of inch, and the stone 

 is seen to haye lost its semi- vitreous lustre and to have 



