Volume LXVIII Niunber 4 



THE 



Botanical Gazette 



Editor: JOHN M. COULTER 



OCTOBER 1919 



Origin and Development of the Pycnidium - - - F. E. Kempton 233 



(With Plates XVII-XXII) 



Ecology of Tilia americana. I. Comparative Studies of the Foliar Tran- 

 spiring Power. Contributions from the Hull Botanical Laboratory 

 253 --------- James E. Cribbs 262 



(With thirteen figures) 



Repeated Zoospore Emergence in Dictynchus - - William H. Weston 287 



<With Plate XXm and one figure) 



Relation of Nutrient Solution to Composition and Reaction of Cell Sap of 



Barley - - -D. R. Hoagland 297 



Briefer Articles 



Paraffin Solvents in Histological Work - - _ - Paul Weatherwax 305 



Current Literature 



Book Reviews ___- __-___- 307 



Notes for Students ___------- 308 



The University of Chicago Press 



CHICAGO, ILLINOIS, U.S.A. 



THE CAMBRIDGE UNIVERSITY PRESS, London and Edinburgh 



THE MARUZEN-KABUSHIKI-KAISHA, Tokyo, Osaka, Kyoto, Fukuoka. Sendai 



THE MISSION BOOK COMPANY. Shanghai 



