Vol. IV. 
MAY, 1917 
No. 5 
AMERICAN 
JOURNAL OF BOTANY 
OFFICIAL PUBLICATION OF THE 
BOTANICAL SOCIETY OF AMERICA 
CONTENTS 
The perennial scapose Drabas of North America. .Edwin Blake Payson 253 
The osmotic concentration of the tissue fluids of Jamaican montane rain- 
forest vegetation . . . . J. Arthur Harris and John V. Lawrence 268 
The viability of radish seeds (Raphinus sativus L.) as affected by high 
temperatures and water content .H. D. Waggoner 299 
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. 
