Great Inventions and Discoveries by Willis Duff Piercy

Tens of thousands of years ago, when the world was even then old, primitive man came into existence. The first men lived in the branches of trees or in their hollow trunks, and sometimes in caves. For food they chased horses or caught fish from the streams along whose shores they lived. If they had clothing, it was the skins of wild beasts. Life was simple, slow, and crude. There were no cities, books, railroads, clocks, newspapers, schools, churches, judges, teachers, automobiles, or elections. Man lived with other animals and was little superior to them. These primitive men are called cave-dwellers.