364 Stiles and j0rgensen.—Studies in Permeability. /. 
tant question of the permeability of plant tissue to the hydrogen ion, as 
more detailed investigations of this are at present in progress in this 
laboratory. 
o 
Absorption of Hydrogen Ions by Potato Tuber from HC 1 . 
Strength of Acid in 
isr 
N 
Conductivity ; that of - 
Time in hours. 
terms of — HC 1 . 
1000 
1000 
being taken as unity. 
0*0 
1*000 
1*000 
0*5 
0*821 
1*0 
0*762 
0*786 
2*0 
0*711 
0*742 
3 *o 
0*711 
4 *o 
0*512 
5 *° 
o*666 
9 *o 
0*319 
18*0 
0*531 
24*0 
0*092 
0*504 
Discussion. 
From the results of the experiments recorded above, it seems reason¬ 
able to conclude that a diffusion of electrolytes between the inside of plant 
tissue and the external solution through the cell membranes is a general 
phenomenon. In our experiments we have dealt mainly with comparatively 
dilute solutions, and generally here the exosmosis has exceeded the move- 
