viii PREFACE 



this includes a discussion of latex plants, drug plants and indus- 

 trial uses of plants taken up in chapters twenty one through 

 twenty three. 



Part Five deals with the harmful aspects of the activities of 

 colorless plants, discussing in chapters twenty four and twenty 

 five the pathogenic bacteria and the parasitic fungi, with their 

 economic importance in destroying useful crop plants. 



Part Six impresses upon the student the enjoyment of plant 

 life by making, him familiar with the wild flowers and the 

 ornamental plants. 



It is hoped that the selection of subject matter and its 

 organization into the present volume will make available 

 material hitherto scattered through various elementary and 

 advanced texts, and may inspire the introduction of a semester 

 course which will appeal to the cultural interests of the general 

 student, acting as a survey of plant science and building at the 

 same time a substantial foundation for further botanical study, 

 while emphasizing the importance of appreciating the various 

 relations of PLANTS AND MAN. 



Clarence J. Hylander 

 Oran B. Stanley 



Hamilton. New Tork 



