The Early Cave-Men

by Katharine Elizabeth Dopp

I. The Pleistocene period.

1. The mid-Pleistocene period.

2. The late Pleistocene period.

II. The Prehistoric period.

III. The Historic period.

Others classify the period with reference to the materials used in making implements and weapons and give us the following:

I. The Stone Age.

1. The Paleolithic or Rough Stone Age.

2. The Neolithic or Polished Stone Age.

II. The Age of Metals.