ts of his body were likely to
be preserved, and only when a growing sense of human dignity led to the
art of sepulture that the preservation of his bones became assured.

The burial art was seemingly not practised by the hunters of the
river-drift period or by men of still earlier date. The only remains of
primitive man known are those found in caves and rock shelters. A number
of human skulls have been discovered in these situations, and in a few
instances skeletons have been exhumed. In the neolithic period interment
became more common and more carefully performed, and the progress of
this period is marked by many remains of man, which in later times were
buried in elaborately constructed stone sepulchres, sometimes massive in
materials and covered by great earth-mounds.

What is meant by the Glacial Age is probably well-known to most readers,
but its close relations to ancient man render it important for those
who are not familiar with its meaning that a passing description of it
should here be given. It will suffice to say that there are found over
much of the northern portions of America and Europe accumulations of
clays, sands, and gravels, sometimes laid down in stratified beds,
sometimes rudely piled together. In these occur blocks of stone, large
and small, and other blocks, occasionally of great size, are found in
isolated localities. The solid rocks which lie beneath these heaps are
often scratched or polished, as if the material had been pushed over
them with great force.

All geologists now believe that these accumulations were made by ice, at
some remote period when a very cold climate prevailed in the northern
hemisphere, and great glaciers slowly made their way southward, grinding
and rending as they went, and burying the land under their mountain-like
heaps, which sometimes were a mile or more in depth. In North America
the glacial ice pushed southward to the 40th degree of north latitude.
In Europe it extended to the Alpine region, but failed to reach the
countries bordering on the Mediterranean.

The elaborate and minute investigation of the glacial deposits has made
it highly probable that there were two glacial eras, two periods in
which the ice pushed down far to the south, and that these were
separated by a period in which the ice retreated and an age of warmer
weather intervened. This is known as the interglacial period. So far as
can be positively ascertained, all the authentic relics of man