264 Induced Variations in NaCl Content of Non- 
Halophytes. 
experiments, but in most cases no trace of piasmolysis was observed 
in leaves which had been immersed for twelve or twenty-seven 
hours. In the other cases only very slight piasmolysis was observed, 
—generally in the upper mesophyll cells. All the cells were living 
at the end of the experiments as they were readily plasmolysed 
with a 10% or 15% salt solution and quickly recovered when placed 
in tap water. In other words the osmotic pressure of the cell sap 
rises, apparently owing to the large amount of sodium chloride 
taken in from the solutions. 
Hill 1 has lately drawn attention to the power of root hairs of 
some halophytes to adapt themselves to varying concentrations of 
salt solutions. 
Miss A. C. Halket, in a recent paper 2 dealing with shoot 
absorption of salt-marsh plants, refers to the variation in weight in 
the leaves of some non-halophytes, e.g., Primula, Tradescantia and 
Myriophyllum when immersed in solutions of sodium chloride, and 
mentions that these leaves were found to decrease in weight when 
immersed for three to four hours. 
Another point of interest is the permeability of the cell-mem¬ 
brane to sodium chloride as shown by the greatly increased salt 
content of the leaves after immersion. The phenomenon is similar 
to that recently described by Messrs. Moore, Roaf and Webster 3 
which led the authors to the conclusion that “ the varying con- 
“ centrations of sodium, potassium, chlorine and phosphatic ions 
“ within and without the cell are an expression of specific affinities 
“ of the definite colloids of each particular cell-type for these ions, 
“ and do not mean that there is a membrane acting as a closed 
“ gate to these ions.” 
1 Hill, T. G. “Observations on the Osmotic Properties of the 
Root-hairsof Certain Salt-Marsh Plants.” New Phytologist, 
Vol. VIII. 
2 Halket, A. C. “ Some Experiments on Absorption by the 
Aerial Parts of Certain Salt-Marsh Plants.” New Phyto¬ 
logist, Vol. X, p. 121. 
3 Moore, 13. ; Roaf, H. E. ; Webster, A. “ Direct Measure¬ 
ments of the Osmotic Pressure of Casein in Alkaline Solu¬ 
tion.” Experimental proof that apparent Impermeability 
of a Membrane to Ions is not due to the Properties of 
the Membrane but to the Colloid contained within the Mem¬ 
brane. Bio-Chemical Journal, Vol. VI, Part I. 
