All cultivated plants have come from pre-existing wild forms by descent with modification. This, however, is Evolution, and we arrive at the conclusion that all these plans of which we know the origin have been evolved from other, different plants which existed before them. The subject of Evolution of Plants treated in this volume deals only with the higher groups of plants since it is impossible to cover the whole ground. The topics dealt are: The Evolution of the true Flowering Plants or Angiosperms. The Evolution of the Seed-plants generally The Evolution of the great groups of the higher Cryptogams i.e. of those Sporeplants which share with the Seed- plants the possession of a vascular system (wood and bast).
