Vol. XXXVII. No. CXLVI. April, 1923 
Price 15s. net. 
Annals of Botany 
EDITED BY 
V. H. BLACKMAN, Sc.D, F.R.S. 
PROFESSOR OF PLANT PHYSIOLOGY AND PATHOLOGY, IMPERIAL COLLEGE OF 
% SCIENCE AND TECHNOLOGY, LONDON 
AND 
R. THAXTER, M.A., Ph.D. 
PROFESSOR OF CRYPTOGAMIC BOTANY IN HARVARD UNIVERSITY, CAMBRIDGE, MASS., U.S.A. 
ASSISTED BY 
D. H. SCOTT, M.A., LL.D., D.Sc., F.R.S. 
LATELY HONORARY KEEPER OF THE JODRELL LABORATORY, ROYAL BOTANIC GARDENS, ICEVV 
J. B. FARMER, M.A., LL.D., D.Sc., F.R.S. 
PROFESSOR OF BOTANY, IMPERIAL COLLEGE OF SCIENCE AND TECHNOLOGY, LONDON 
F. W. OLIVER, M.A., D.Sc., F.R.S. 
QUAIN PROFESSOR OF BOTANY, UNIVERSITY COLLEGE, LONDON 
AND OTHER BOTANISTS 
LONDON 
HUMPHREY MILFORD, OXFORD UNIVERSITY PRESS 
AMEN CORNER, E.C. 
Edinburgh, Glasgow, New York, Toronto 
Melbourne, Cape Town, and Bombay 
1923 
Printed in England at the Oxford University Press 
