Note 72 — Chapter II · MAN’S FIRST WEAPONS—THE STONE AND THE STICK. THE EARLIEST AGES OF WEAPONS. THE AGES OF WOOD, OF BONE, AND OF HORN.
Reading edition
In Denmark the division is marked even by the vegetation. The Stone Age lies buried under the fir-trees; the oak-stratum conceals the Bronzes, and the Iron Age is covered by birch and elders (Jähns, p. 2).