The first four chapters are introductory. They lay the foundation for what follows. Chapters five through twelve are the heart of the story. They describe the anvils of adversity on which the plants of our day were forged through the ages: the Coal Age, Drifting Continents, and the Ice Age. Beginning with Chapter thirteen, the last eight chapters deal with the pattern of the countryside as it is today, showing how our trees and flowers have traveled around the world to reach their present locations.