Vol. II 
JULY, 1915 
No, 7 
AMERICAN 
JOURNAL OF BOTANY 
OFFICIAL PUBLICATION OF THE 
BOTANICAL SOCIETY OF AMERICA 
CONTENTS 
The exchange of ions between the roots of Lupinus albus and culture solu- 
tions containing two nutrient salts. 
Rodney H. True and Harley Harris Bartlett 311 
The probable non- validity of the genera Botryodiplodia, DiplodieUa, Chae- 
todiplodia, and Lasiodiplodia J. J. Taubenhaus 324 
Factors influencing flower size in Nicotiana with special reference to ques- 
tions of inheritance .T. H. Goodspeed and R. E. Clausen 332 
PUBLISHED 
IN COOPERATION WITH THE BOTANICAL SOQETY OF AMERICA 
BY THE 
BROOKLYN BOTANIC GARDEN 
At 41 North Queen Street, Lancaster, Pa. 
Entered as swcond-clasa matter February ai. 1914. the post office at Lancaster. P'onaylvauid, 
under the act of March 3, 1879. 
