44 
Walter Stiles and Ingvar Jorgensen. 
In Tables IV to VI vve give the results of the plasmolytic 
experiments on sections cut from the same three roots. We have 
Table IV. 
Plasmolysis of Beet Root Cells in solutions of Sodium Chloride. 
(Beet No. 1). 
Concentration of Salt. 
Condition of cells after 30 minutes. 
0-33 N 
No plasmolysis. 
0-44 N 
Plasmolysis slight but noticeable. 
0-50 N 
Good plasmolysis. 
0-67 N 
Strong 
0-80 N 
100 N 
Very strong plasmolysis. 
Table V. 
Plasmolysis of Beet Root Cells in solutions of Sodium Chloride. 
(Beet No. 2). 
Concentration of Salt. 
Condition of cells after 60 minutes. 
0-25 N 
No plasmolysis. 
0-33 N 
11 M 
0 40 N 
Plasmolysis just starting in a few cells. 
0-45 N 
Slight plasmolysis in practically all cells. 
Table VI. 
Plasmolysis of Beet Root Cells in solutions of Sodium Chloride. 
(Beet No. 3). 
Concentration of Salt. 
Condition of cells after 60 minutes. 
0-25 N 
No plasmolysis. 
0 33 N 
»» i y 
0-40 N 
Incipient plasmolysis in a few cells. 
0-45 N 
Slight plasmolysis in most cells. 
already touched on the difficulty arising from differences between 
different cells of the same tissue as regards the concentration of the 
salt solution required to produce plasmolysis, so that when we speak 
of a plasmolysing concentration for the tissue as whole we are 
necessarily involved in an approximation. However, in the cases of 
all three series we should say that the concentration which just 
failed to produce plasmolysis in the majority of the cells was 0.4 N, 
and we should therefore conclude that a solution of 0.4 N sodium 
chloride is approximately isotonic with the cell sap. 
Thus the change in weight method and the plasmolytic method 
gave the same value for the concentration of sodium chloride 
