Vol. V. 
APRIL, 1918 
No. 4 
AMERICAN 
JOURNAL OF BOTANY 
OFFICIAL PUBLICATION OF THE 
BOTANICAL SOCIETY OF AMERICA 
CONTENTS 
Copper and zinc as antagonistic agents to the ''alkali" salts in soils. 
C. B. LiPMAN and W. F. Gericke 151 
The effect of tobacco smoke and of methyl iodide vapor on the growth of 
certain microorganisms C. A. Ludwig 171 
The vertical distribution of Vol vox in the plankton of Lake Monona. 
Gilbert Morgan Smith 178 
A comparison of salt requirements for young and for mature buckwheat 
plants in water cultures and sand cultures. 
John W. Shive and William H. Martin 186 
Cell measurement as an aid in the analysis of quantitative variation. 
Wilber Brotherton, Jr., and H. H. Bartlett 192 
Respiration and catalase activity in sweet corn. . . Charles O. Appleman 207 
Some new species of Inocybe.. ................. .George F. Atkinson 210 
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 
