PRINCIPLES OF BOTANY 



BY 



JOSEPH Y. BERGEN, A.M. 



Al'THOR OF "ELEMENTS OF BoTANY," ''FOUNDATIONS <>F BOTANY," 

 " PRIMER OF DARWINISM," ETC. 



AND 



BRADLEY M. DAVIS, PH.D. 



HEAD OF DEPARTMENT OF BOTANY IN THE MARINE BIOLOGICAL 



LABORATORY, RECENTLY ASSISTANT PROFESSOR OF PLANT 



MORPHOLOGY IN THE UNIVERSITY OF CHICAGO 



GINN & COMPANY 



BOSTON NEW YORK CHICAGO LONDON 



