PLOWER — DISCOVERIES OF ELINT IMPLEMENTS. 455 



regarded merely as tlie characteristic fossils of certain river-valley 

 gravels, without reference to the condition of either previous to their 

 being brought together. But although the conditions of either 

 deposit can hardly fail to throw light upon the history of the other, 

 each has undoubtedly a history and (geologically) a date of its 

 own ; the implements, although in the gravel, are not of it, except 

 in a certain limited sense. The one is the product of human skill, 

 the other the result of natural causes ; and it is essential to con- 

 sider them separately, as well as in their connexion with each other. 



When first observed, the implements had always been found in the 

 immediate neighbourhood of river-channels, and assuming (as it seems 

 usually to have been assumed) that they had been carried from the 

 places in which they were made, it was reasonable to ascribe their trans- 

 port to those rivers ; but this was but a presumption which, however 

 reasonable, was liable to be rebutted. Because certain objects are 

 found in or near the banks of rivers, it by no means follows that 

 they must of necessity have been carried thither by the rivers ; they 

 may have been deposited by other means, and possibly even before 

 the rivers had an existence, and there seems good reason for believing 

 that as regards many, or indeed most, of these flint implements this 

 may have been the case. 



At the commencement of the Quaternary epoch, when, by the re- 

 tiring of the sea, or the elevation of its bed, the Cretaceous and 

 Tertiary strata became dry land, it cannot be doubted that the surface, 

 in many places, was, as it still remains, strewn, especially in valleys 

 and hollows, with fragments of various rocks — the wreck and ruin 

 of beds which had been broken up and dispersed. Of these a large 

 proportion would consist of nodules of flint which had been 

 washed out of the upper chalk-beds, or from which the chalk had 

 been removed by decomposition. Abundant materials would thus be 

 provided for the makers of implements and weapons, and the fol- 

 lowers of this primitive industry would naturally resort to those 

 spots on which the best material was to be found. The condition 

 in which we find them is quite consistent with the belief that 

 the stone from which the implements were formed had previously 

 been long exposed upon the surface. At one time, therefore, 

 the raw material and the manufactured were alike lying upon 

 the surface, and after some interval of unknown but probably very 

 extended duration, both were alike overwhelmed by those masses of 

 sand and gravel beneath which we now see them. This interval 

 doubtless involved important changes, including perhaps the oblite- 

 ration of ancient river-channels and the formation of new ones. 



If, as has been sometimes supposed, the implements were carried 

 about by river-floods, or by deluges, whether marine or of fresh 

 water, we should expect to find them confusedly intermingled with 

 the sands and gravels, and they would be strewn continuously along 

 the whole course of the valleys. This, however, seems not to be the 

 case ; for although the gravel-beds are continuous (frequently for 

 several miles), the implements hitherto have been found only at de- 

 tached spots, often far apart, and which were probably visited on 



