Oct., 1921] 
RABER PERMEABILITY 
combined with bivalent or trivalent anions the increase is less and may be 
entirely lacking. 
Laboratory of Plant Physiology, 
Harvard University. 
BIBLIOGRAPHY 
1. Osterhout, W. J. V. The effect of some trivalent and tetravalent kations on per- 
meability. Bot. Gaz. 59: 464-473. 191 5. 
2. . On the decrease of permeability due to certain bivalent kations. Bot. Gaz. 59: 
317-330. 1915. 
3. Raber, Oran L. A quantitative study of the effect of anions on the permeability of 
plant cells. Jour. Gen. Physiol. 2: 535-539. 1920. 
4. . The antagonistic action of anions. Ibid. 2: 541-544. 1920. 
5. . The synergetic action of electrolytes. Proc. Nat. Acad. Sci. 3: 682-685. 1917. 
