THE 



SCIENTIFIC PROCEEDINGS 



OF THE 



ROYAL DUBLIN SOCIETY. 



Yol. XIII. (KS.), m. 19. APRIL, 1912. 



VARIATIONS IN THE OSMOTIC PRESSURE OF 

 THE SAP OF THE LEAVES OF HEDERA 

 HELIX. 



BY 



HENRY H. DIXON, ScD., F.R.S., 



UNIVERSITY PEOFESSOK OF BOTANY, TRINITY COLLEGE, DUBLIN, 



AND 



W. R. G. ATKINS, M.A., A.I.C., 



ASSISTANT TO THE PROFESSOR OF BOTANY, TRINITY COLLEGE, DUBLIN. 



\_A uihors alone are responsible for all opinions expressed in their Communications.^ 



DUBLIN 



PUBLISHED BY THE EOYAL DUBLIN SOCIET 



LEINSTER HOUSE, DUBLIN. 



WILLIAMS AND NORGATE, 



14, HENRIETTA STREET, COVENT GARDEN, LONDON. W-C. 



1912. 



Price Sixpence. 



