The Influence of Immersion in Certain Electrolytic 
Solutions upon Permeability of Plant Cells. 
BY 
MAUD WILLIAMS, B.Sc. 
With two Figures in the Text. 
M UCH recent work upon the cells of plants shows the permeability of 
the cell protoplasmic membrane to undergo modification during 
immersion in certain solutions. Such immersion may cause the exit of con¬ 
stituents of the sap which are normally unable to penetrate the membrane, 
or it may render possible the entrance of materials from outside the cell, 
which are unable to pass into the cell in the ordinary course. 
Czapek, as a result of his study of the influence of ethers, alcohols, &c. 
(1), comes to the conclusion that surface tension of the liquid surrounding the 
material is the chief factor in producing these abnormal permeabilities. 
According to this writer ‘ all substances of the most different chemical 
character began to injure the cell just when the surface tension had reached 
the critical value 5 ( 2 ). This critical surface tension is stated to be £ about 
two-thirds relatively to that of water \ On the other hand, there are 
numerous experiments which show that the cell-membrane may be rendered 
permeable to the electrolytes contained in the vacuole by immersion in 
electrolytic solutions of which the surface tensions are far removed from 
Czapek’s critical value. Thus Miss Hind records abnormal permeability 
produced by immersion in very dilute acids ( 3 ), while Stiles and Jorgensen 
obtain similar results for many solutions, including magnesium and sodium 
chlorides ( 4 ). 
Since surface tension considerations alone cannot explain the altera¬ 
tions of permeability other possibilities must be considered, and it is of 
interest to find how far the time of immersion in a particular solution affects 
the question. 
An endeavour has here been made to deal throughout with one type of 
plant cell and 
{a) to find what solutions are capable of rendering the protoplasm 
permeable to one particular material to which it is normally 
impermeable; 
[Annals of Botany, Vol. XXXII. No. CXXVIiI. October, 1918.] 
