404 ME. T. CODRTNGTON ON THE [Aug. IQ09, 



bank to which detritus is brought down from the tributary valley 

 that is the case with only 45 per cent., those worn and polished 

 outnumbering those retaining their sharpness by one-fourth. 



The explanation seems to be that, whether on the right bank or 

 on the left, specimens that retain their sharpness are implements, 

 fragments, and flakes made on the spot, and that those worn and 

 blunted have been brought down with other detritus by spruits in 

 the rains. On the right bank spruits are short and insignificant 

 above the Falls, and almost absent on the promontory below ; 

 while on the left bank, though many implements were made on the 

 ground above and below the Falls, most of the artificially-worked 

 stones were brought down by the flooded spruits from the tributary 

 valley. 



With respect to the origin of the burnish, so conspicuous on many 

 of the stones as they lie on the surface under the brilliant African 

 sun, it is to be noticed that there is a considerable difference in the 

 amount of the polish on specimens from the different areas. On 

 those from the top of the ridge there is none, nor is there any on 

 those from the Maramba Valley ; those from the right bank above 

 the Falls have little or none, while those from the tongue of land 

 below the Falls generally have some, and a few a good deal of 

 polish. Of the 130 specimens from that part of the left bank 

 draining direct to the Zambesi, not more than six are without some 

 polish, and many are highly polished. A view of the whole of the 

 specimens collected shows that abrasion and polish or burnish go 

 together, those with sharp angles having little or no polish, while 

 those that are highly polished are much worn. As far as it goes, 

 the evidence seems to be in favour of sand-polish rather than glazing 

 by a film on the surface. 



With regard to the age of the implements, that found by 

 Mr. Balfour and four found by me are of palaeolithic type, the first 

 and one of the latter being unworn and sharp, while the three of 

 a brown quartzite, which seems to come from the Upper Maramba, 1 

 are much rolled. None of them were found embedded in a gravel 

 or other deposit. 



The implement found by Mr. Lamplugh in Maramba gravel 3 or 

 4 miles from the Zambesi has its chipping freshly preserved, and 

 the flake found by me at the base of the same gravel close by is 

 unworn. The gravel, resting directly upon the basalt 7 or 8 feet 

 above the bed of the Maramba, may be of considerable age ; though, 

 on the other hand, it is far below the level of present Maramba 

 floods and may be comparatively recent. Nor can any conclusion 

 be drawn from the finding of the implement beneath 10 feet of 

 drifted sand. 



1 The three of brown quartzite are very like implements from India in the 

 Cape Town Museum, labelled as ' greatly resembling South African implements 

 in material and workmanship.' 



