Bouyouöos, Transpiration of Wheat Seedlings as Affected etc. 
15 
Table VII. 
Density of Cell Sap of Bean Seedlings as Determined by the Electrical 
Resistance Method. 
P. p. m. of Solution Resistance of Cell Sap 
in Which Plants Grew in Ohms 
750 1479.6 
4500 1158.1 
These figures show most strikingly that the foregoing relation 
holds true also with beans. It will be noticed that the 4500 P. p. m. 
solution gave cell sap with 321.5 ohms more concentration than 
the 750 P. p. m. solution. 
Experiment IV. This experiment consisted of growing wheat 
seedlings for 15 days in Solutions of 
N 
50 
and 
N 
250 
of CaCb to each 
one of which was added exactly the same amount of a complete 
nutrient solution in Order that the plants may make a normal growth. 
The object of this series was to see whether the density of the 
cell sap of the plants grown in different densities of the non- 
nutrient solution, would run in the same Order as that of the dif¬ 
ferent concentrations.of the complete nutrient solution already noted. 
The cell sap was extracted in this case, from 1.6330 grams of 
green weight, diluted to 200 cc., and the density determined by 
the electrical resistance method. Following are the results obtained. 
Table VIII. 
Density of Cell. Sap of Wheat Seedlings as Determined by the Electrical 
' Resistance Method. 
P. p. m. of Solution 
in Whicli Plants Grew 
N 
CaCl 2 
N 
OaCl 2 £Q 
Resistance of Cell 
Sap in Ohms 
1007.2 
952.8 
It is evident that even with the non-nutrient salt Solutions, 
the concentrations of the cell sap decreased with the decline in 
density of the solution. Itwillbe apparent that in the case of the 
N 
solution, the resistance of the cell sap is 54.4 ohms less than 
50 
N 
that of the solution. 
2o0 
It seems then from all the preceding experiments, that the 
assumption originally made, namely, that the density of the cell 
sap may be proportional to the concentration of the solution in 
which the plants are growing, is correct, or at least the foregoing 
data have confirmed it in every case without a single exception. 
If it is true that there is a close relation between the den¬ 
sity of the cell sap and that of the outside solution, this would at 
