Vol. V. 
JUNE, 1918 
No. 6 
AMERICAN 
JOURNAL OF BOTANY 
OFFICIAL PUBLICATION OF THE 
BOTANICAL SOCIETY OF AMERICA 
CONTENTS 
Breeding for disease resistance in plants W. A. Orton 279 
Behavior of plants in unventilated chambers. 
F. C. Newcombe and Etta A. Bowerman 284 
Segregation of susceptibility to parasitism in maize . . , . .Donald F. Jones 295 
The value of certain nutritive elements in the development of the oat plant. 
James Geere Dickson 301 
Uredinales of Guatemala based on collections by E. W. D. Holway. 
J. C. Arthur 325 
PUBLISHED 
IN COOPERATION WITH THE BOTANICAL SOCIETY OF AMERICA 
BY THE 
BROOKLYN BOTANIC GARDEN 
At 41 North Queen Street, Lancaster, Pa. 
Entered as second-class matter February 21, 1914, at the post office at Lancaster, Pennsylvania, 
* under the act of March 3, 1879. 
