48 Diffusion and Osmotic Pressure 



important pieces of research, mainly for the more recent 

 ones. References are not given for material which may be 

 regarded as a matter of common knowledge. To those who 

 wish full citations for the period up to the time of its publi- 

 cation, Ewart's admirable translation of Pfefifer's Physiology 

 of Plants will be found of great service. 



