ELEMENTARY 

 PLANT PHYSIOLOGY 



BY 



DANIEL TREMBLY MACDOUGAL, Pn.D, 



Director of the Laboratories, New York Botanical Garden 

 Author of "Practical Text-Book of Plant Physiology" 



WITH ONE HUNDRED AND EIGHT ILLUSTRATIONS 



LONGMANS, GREEN, AND CO. 



91 AND 93 FIFTH AVENUE, NEW YORK 



LONDON AND BOMBAY ^ 



1906 



