In peat-beds, under the remains of trees that in those localities have long ago become extinct, his relics are still found, the implements that accompany him indicating a distinct chronological order.

Near the surface are those of bronze, lower down those of bone or horn, still lower those of polished stone, and beneath all those of chipped or rough stone.

The date of the origin of some of these beds cannot be estimated at less than forty or fifty thousand years.
The caves that have been examined in France and elsewhere have furnished for the Stone age axes, knives, lance and arrow points, scrapers, hammers.

The change from what may be termed the chipped to the polished stone period is very gradual.

It coincides with the domestication of the dog, an epoch in hunting-life.