in a deposit hard enough for the hollowing out of tombs, which are
certainly earlier than the eighteenth dynasty. We must add, however,
that neither with the Palaeolithic nor with the Neolithic relics have
been found any bones of extinct animals. Some savants go yet further:
they think that these worked stones are but chips split off by the
heat of the sun.[37] A phenomenon of this kind is mentioned by Desor
and Escher de la Linth in the Sahara Desert; Fraas quotes a similar
observation made by Livingstone in the heart of Africa, and one by
Wetzstein, who, not far from Damascus; saw hard basalt rocks split
under the influence of the early morning freshness. I have myself
noticed similar phenomena in the Nile valley, but it must be added
that the fragments of rock broken off by the combined influence of
heat and humidity present very notable differences to those worked
by the hand of man, and cannot really be mistaken for them.

In Algeria have been preserved some most interesting relics of
prehistoric times. If I am not mistaken, Worsaae was the first to
note the worked stones in the French possessions in Africa. They have
been picked up in great numbers, especially near the watercourses at
which the ancient inhabitants of the country slaked their thirst,
as do their descendants at the present day. The exploration of the
Sahara daily yields unexpected discoveries; and already fifteen
different stations formerly inhabited by man have been made out. In
those remote days a large river flowed near Wargla, which was then
an important centre, and a number of tools picked up bear witness to
the former presence of an active and industrious population. At one
place the flint implements, arrow-heads, knives, and scrapers are
all of a very primitive type, and were found sorted into piles. This
was evidently a DEPOT, probably forming the reserve stock of the
tribe. Wargla or perhaps Golea at one time appears to have been the