A 



FOR 



COLLEGES AND UNIVERSITIES 



BY MEMBERS OF THE BOTANICAL STAFF OF THE 

 UNIFERSITT OF CHICAGO 



JOHN MERLE COULTER, PH.D. 



PROFESSOR OF PLANT MORPHOLOGY 



CHARLES REID BARNES, PH.D. 



LATE PROFESSOR OF PLANT PHYSIOLOGY 



HENRY CHANDLER COWLES, PH.D. 



ASSOCIATE PROFESSOR OF PLANT ECOLOGY 



VOL. II. ECOLOGY 



NEW YORK : CINCINNATI : CHICAGO 



AMERICAN BOOK COMPANY 



