I ■ 
VoL VI. MAY, 1919 No. 5 
AMERICAN 
JOURNAL OF BOTANY 
OFFICIAL PUBLICATION OF THE 
BOTANICAL SOCIETY OF AMERICA 
CONTENTS 
Osmotic pressures in the potato plant at various stages of growth. 
B. F. LUTMAN 181 
C3^tandreae Hawaiienses, Sect. Microcalyces Hillebr . . Joseph F. Rook 203 
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 Fejbruary 21, 1914, at the post office at Lancaster, Pennsylvania, 
under the act of March 3, 1879 
