Vol. IV. 
NOVEMBER, 1917 
No. 9 
AMERICAN 
JOURNAL OF BOTANY 
OFFICIAL PUBLICATION OF THE 
BOTANICAL SOCIETY OF AMERICA 
CONTENTS 
Effect of soil temperature on the growth of bean plants and upon their sus- 
ceptibility to a root parasite. Donald Reddick 513 
The development of Gortinarius pholideus W. H. Sawyer, Jr. 520 
Leaf-structure as related to environment Herbert C. Hanson 533 
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. 
