THE GENESIS AND MIGRATIONS OF PLANTS.

DEDICATED TO THE MEMORY OF DR. OSWALD HEER, The Able and Successful Student of the later Floras of the Northern Hemisphere.

Geological Periods as Related to Plants—Arctic Origin of Floras—The Devonian Flora—Arctic Climates of the Past—History of Some Modern Forms—Laws of the Succession

Vegetation of the Middle Devonian or Erian, restored from actual specimens (p. 202).