438 | ANNUAL REPORT SMITHSONIAN INSTITUTION, 1958 
stances where no question of tool making arises? There is a great 
need, too, for experimental work on the lines of that by the late Pro- 
fessor Barnes and Mr. Warren, but designed to investigate the forces 
required to split quartzite pebbles. My own extremely limited obser- 
vations in Africa suggest that at least some Kafuan-like flakings are 
produced when gravel is carried over waterfalls.° As for secondary 
chipping, it should not be forgotten that soil creep or solifluxion can 
occur under tropical conditions as well as under glacial. 
One of my reasons for being skeptical about the Kafuan “pebble 
tools” is their prodigality. In the summer of 1955 I was with a party 
on safari through the Katanga Province of the Belgian Congo, and 
we were taken by Prof. G. Mortelmans to an exposure of gravels at 
Kafila near Elisabethville. Within a few minutes all the members 
of the party had found more “pebble tools” in this gravel than they 
could carry away. It is true that artifacts are astonishingly abun- 
dant at some African localities on the later hand-ax horizons, but 
the profusion of chipped pebbles in the Kafilan gravel reminded me 
of the profusion of eoliths in the Sub-Crag Stone Bed. Miles Burkitt 
evidently has similar reservations to make about the Kafuan pebbles, 
for he wrote recently: “From a study of the objects themselves it is 
not easy to find enough evidence to prove that they must be the handi- 
work of Man and that the fracturing cannot have been produced by 
natural forces.” There has been an undeniable tendency among us all 
to argue subconsciously like this: “Man could have made these; they 
are of the right age for the beginning of culture; this is where we 
may expect to find artifacts; these are artifacts.” 
Fortunately there are certain situations in which fractured stones 
are acceptable as artifacts, even when the flaking appears random or 
accidental. For example, many of the fragments of quartz in the 
Choukoutien cave deposits would not be recognized as humanly struck 
if they were found on the surface away from their human context. 
The quartz found at Choukoutien is foreign to the site, and can only 
have been introduced into the cave by human agency. Another situ- 
ation in which flaked stones are more readily acceptable as artifacts is 
where they occur isolated in an otherwise stoneless layer of lacustrine 
mud or sand. 
Tf we discount the Kafuan pebbles, the oldest undoubted artifacts in 
the world are related to or equivalent to the Oldowan culture, first 
recognized by Dr. L. S. B. Leakey in the basal bed of the series of la- 
custrine sediments exposed in the side of the Oldoway (Olduvai) 
6 Perhaps mainly when, under a semiarid climate, large masses of gravel are suddenly 
moved over falls at the commencement of the rains, with the result that a proportion of 
the stones collide out of water. Since this paper was published, Dr. J. D. Clark has demon- 
strated that Kafuan-type flaking does occur through stones falling from the sides of 
gorges and striking other stones or rock surfaces out of water (Proc. Prehist. Soc., vol. 34, 
for 1958). 
