a deposit of soot on the roof.

But it must be remembered that these subterranean passages have been
sealed up from time immemorial, and subjected to no invasion by man or
beast, or to any change of air or temperature. And secondly, that the
artists obtained light from melted fat in stone bowls on the floor, in
which was a wick of pith; and such lamps would hardly discolour ceiling
or walls. Of the genuineness of these paintings and sculptures there
can be no question, from the fact that some are partly glazed over and
some half obliterated by stalagmitic deposits.

Another discovery made in the Mas d'Azil in Arriege, is of painted
pebbles and fan-shells that had served as paint-pots. [Footnote: Piette
(E.), _Les Galets colorres du Mas d'Azil._ Paris, 1896.] The
pebbles had been decorated with spots, stripes, zig-zags, crosses, and
various rude figures; and these were associated with paleolithic tools.
In the chalk of Champagne, where there are no cliffs, whole villages of
underground habitations have been discovered, but none of these go back
to the earliest age of all; they belong to various epochs; but the
first to excavate them was the Neolithic man, he who raised the rude
stone monuments elsewhere. He had learned to domesticate the ox and the
sheep, had made of the dog the friend of man. His wife span and he
delved; he dug the clay, and she formed it with her fingers into
vessels, on which to this day her finger-prints may be found.

These caves are hollowed out in a thick bed of cretaceous rock. The
habitations are divided into two unequal parts by a wall cut in the
living chalk. To penetrate into the innermost portion of the cave, one
has to descend by steps cut in the stone, and these steps bear
indications of long usage. The entrance is hewn out of a massive screen