470 
AMERICAN JOURNAL OF BOTANY 
[Vol. 8, 
chloride, independent of the hydrogen-ion concentration. The difference 
seems to depend upon the valency. 
Laboratory of Plant Physiology, 
Harvard University 
LITERATURE CITED 
1. Raber, O. L. The effect upon permeability of polyvalent cations in combination with 
polyvalent anions. Amer. Jour. Bot. 8: 382-385. 1921. 
2. Osterhout, W. J. V. The effect of alkali on permeability. Jour. Biol. Chem. 19: 335. 
1914. The effect of acid on permeability. Ibid. 19: 493. 1914. 
3. , The effect of some trivalent and tetravalent cations on permeability. Bot. 
Gaz. 59: 464. 1915. 
4. . On the decrease of permeability due to certain bivalent cations. Bot. Gaz. 59: 
317. 191S. 
