The 



Plant World 



j\ Magazine of General Botany 



VOLUME 12 

 NUMBER 5 

 MAY 1909 



Containing 



Darwinism and Experimentation in Botany 



By D. F. MacDougal 97 



Vegetation Problems Involving Climate 



By Edgar N. Transeau 102 



A Summer Laboratory for Mountain Botany 



By Francis Ramaley and W. \V. Robbins 105 



Books and Current Literature 1 10 



Notes and Comment 118 



Tucson, Arizona 



Entered as Second C fas s Matter, Dec. 17, 1907 , at the Post-Office, Tucson, 

 Arizona, under the. Act of Congress of March 3, 1879. 



