BOTANICAL GAZETTE [APRIL 
rapid nor as great and the fall is slow, especially at first. The 
concentration was 0.005 M (1.1 gm. to 1ooocc. sea water). The 
results are shown in table X and fig. 10. Dead tissue showed no 
rise In resistance. 
328 
TABLE X 
ELECTRICAL RESISTANCE OF Laminaria saccharina 
| Tooo cc. 
Time in hours | (CAC HO) eA _ gm. In sea water 
| 
| 
° 850 860 
i 0 ape 
I 920 
2 930 ee 
ee gio 840 
223 870 820 
45 600 680 
All readings were taken at 18°C. 
1000 OHMS 
| 
800, NSF ee 
700 
5 10 20 30 HOURS 
Fic. 10.—Curve of electrical resistance of Laminaria saccharina in sea water 
tooo ec.+(CdCl.+ 2H,O) 1.1 gm. (=0.005 M) (unbroken line) and of a control in 
sea water (dotted line). 
A very different type of curve is obtained by using SnCl, 
+2H.0. The rise is rapid and decided and the fall is much more 
rapid than with any of the other substances used. The solution 
was acid to litmus, but the effect cannot be considered as due to 
the acidity alone. Dead tissue showed no rise in resistance. 
