itive
man. These indicate not only great remoteness of origin, but also a very
gradual advance from the lowest stage of inventive ability to the high
level now attained.

These relics of primitive man are divided by Dana into ten varieties,
(1) Buried human bones; (2) stone arrow and lance heads, hatchets,
pestles, etc.; (3) flint chips, left in the manufacture of implements;
(4) arrow heads and other implements made of bone and deer horn; (5)
bones, teeth, and shells bored or notched by human hands; (6) cut or
carved wood; (7) bone, horn, ivory, or stone graven with figures, or cut
into the shapes of animals; (8) marrow bones broken longitudinally to
obtain the marrow for food; (9) fragments of charcoal and other
indications of the use of fire; (10) fragments of pottery.

Relics of the kinds above cited have been found at intervals for many
years past, but their age and significance were doubted, and only within
some forty years has the great antiquity of man upon the earth been
generally acknowledged by scientists. The most important early find of
ancient implements was made by Boucher de Perthes in 1841 and
subsequently, in the high level gravels of the valley of the Somme, in
Picardy, France. In deep layers of these gravels, which were deposited
at a period when the river occupied a wider and higher channel than at
present, he found rude flint weapons and tools, bearing plain evidences
of human workmanship, and mingled with the teeth and bones of animals,
both of living and extinct species. Among the bones were those of the
mammoth and the hairy rhinoceros, species evidently contemporary with
man, though they have long since vanished from the earth. At a somewhat
earlier date, implements of men, mingled with bones of the cave-bear,
cave-lion, hyena, and other species, had been found in the caves of
France and Belgium. These were frequently buried beneath deposits of
stalagmite and other materials that must have taken a long time to
accumulate.

The significance of these discoveries was long in forcing itself upon
the attention of scientific men. Nearly twenty years passed before
Boucher de Perthes could get the noted geologists of France and England
to investigate the Somme gravels. When they did so they were quickly
convinced of the genuine antiquity of these relics, and announced it as
a fact beyond question that man had lived in the Somme valley and
fashioned rude implements out of flint during what was known