chalk hills in the vicinity; in portions of them, upon the hills, often
in company with the flints, are discovered numerous bones of the extinct
mammalia, such as the mammoth, the fossil rhinoceros, tiger, bear,
hyena, stag, ox, horse, and others.

The flint implements are found in the lowest beds of gravel, just above
the chalk, while above them are sands with delicate fresh-water shells
and beds of brick-earth,--all this, be it remembered, on table-lands two
hundred feet above the level of the sea, in a country whose level and
face have remained unaltered during any historical period with which we
are acquainted. "It must have required," says Sir Charles Lyell, "a
long period for the wearing down of the chalk which supplied the broken
flints (stones) for the formation of so much gravel at various heights,
sometimes one hundred feet above the level of the Somme, for the
deposition of fine sediment, including entire shells, both terrestrial
and aquatic, and also for the denudation which the entire mass of
stratified drift has undergone, portions having been swept away, so
that what remains of it often terminates abruptly in old river-cliffs,
besides being covered by a newer unstratified drift. To explain these
changes, I should infer considerable oscillations in the level of the
land in that part of France, slow movements of upheaval and subsidence,
deranging, but not wholly displacing the course of ancient rivers."

The President of the British Association, in his opening speech at
the meeting of 1860, affirms the immense antiquity of these flint
implements, and remarks:--"At Menchecourt, in the suburbs of Abbeville,
a nearly entire skeleton of the Siberian rhinoceros is said to have been
taken out about forty years ago,--a fact affording an answer to the
question often raised, as to whether the bones of the extinct mammalia
could have been washed out of an older alluvium into a newer one, and