CHARACTER OF THE TRUE DRIFT IMPLEMENTS. 353 



which they occur, and as the remains of extinct mammalia 

 with which they are associated. 



It has been suggested by some writers, that though they 

 are really found in the mammaliferous gravel, they may be 

 comparatively recent, and belong really to the Neolithic or 

 later Stone Age, but have gradually sunk down from above 

 by their own weight, or perhaps have been buried in artificial 

 excavations. There are, however, no cracks or fissures by 

 which the hatchets could have reached their present posi- 

 tions, and the strata are too compact and immovable to 

 admit of any such insinuation from the surface. Nor 

 could any ancient excavations have been made and filled 

 in again without leaving evident traces of the change. 

 Moreover, we may in this case also appeal to the flint im- 

 plements themselves, which, as we have already seen, agree 

 in colour and appearance with the gravel in which they 

 occur ; and it seems, therefore, only reasonable to infer that 

 they have been subjected to the same influences. Moreover, 

 if they belonged to the later Stone period, and had found 

 their way by any accident into these gravels, then they ought 

 to correspond with the other flint implements of the Stone 

 period. But this is not the case. The flakes indeed, offer no 

 peculiarities of form. Similar splinters of flint, or obsidian, 

 have been used in the absence of metal by savage tribes in 

 almost all ages and all countries. The other implements, 

 on the contrary, are very characteristic. They are almost 

 always made of flint, whereas many other minerals, such, for 

 instance, as serpentine, jade, clayslate, etc., were used in the 

 later Stone Age. Their forms are also peculiar ; some are 

 oval (pi. 1, fig. 11), chipped up to an edge all round, and from 

 two to eight or nine inches in length. A second type is also 

 oval, but somewhat pointed at one end (pi. 1, fig. 10, and figs. 

 195, 196). Others again (figs. 197, 198) have a more or less 

 heavy butt at one end and are pointed at the other. Mr, 



2A 



