468 BOTANICAL GAZETTE [JUNE 
of 17 hours it fell to 980 ohms, while that of the control fell 50 ohms 
in the sime time. Dead tissue gave no rise in resistance. 
TABLE III 
ELECTRICAL RESISTANCE OF Laminaria saccharina 
| 
In sea water 300 cc.+ 
Time in hours Fe wae ee 12 eg In sea water 
Pgs ee Mite Mees teat mets 840 810 
OVO ee ae OO ae hee is ra pikes 
7h geben heater re RAEN DIO Gets ie oa lige 
BS ee ee OU re Se i a 
gle Gl | eta icaneg Ui 860 800 
PO. ee ee pes 420 770 
All readings were taken at 18° C. 
The addition of the salt in solid form increases the conductivity 
of the solution. In order to produce a rise in resistance when added 
1000 OHMS 
400 x 
| oe. 10 HOURS 
Fic. 3.—Curve of electrical resist- 
ance of Laminaria saccharina in sea 
water+Ce,(NO,)s-12  H,O 0.8 gm. 
(=0.003 M) (unbroken line), and of 
a control in sea water (dotted line). 
3The frond may be 
in this way, the action of the salt 
must be great enough to overcome 
the fall in the resistance of the 
solution which is contained in the 
apparatus and in the intercellular 
substance’ of the tissue. 
As has been pointed out," such 
experiments furnish conclusive 
proof that the current passes 
through the protoplasm as well 
as through the intercellular 
substance. 
In a previous paper the results 
of exposing the tissue alternately 
to sea water and to sea water+ 
La.(NO,)s were described in detail. 
The experiment shows that re- 
peated exposure to sea water+ 
La,(NO;)s produces no injury.‘ 
mass of intercellular substance in which 
regarded 
numerous masses of protoplasm (the cells) are imbed 
4 Science 36:350. 1912. 
