xii Contents 



CHAPTER PAGE 



XVI. The method of origin of new species and structures, and the 



CAUSES of their FITNESS TO THE PLACES THEY LIVE IN. {Evolutiotl 



and Adaptation) 403 



XVII. The remarkable improvement made in plants by man, and the 



WAY HE BRINGS IT ABOUT. {Plant breeding) 426 



XVIII. The principal groups into which plants naturally fall, 



WHETHER BY RELATIONSHIP OR HABIT. (Classification) 445 



Index 467 



