472 BOTANICAL GAZETTE [JUNE 
1000 cc. sea water (=o.01 M). It is evident that aluminum salts 
are very toxic. ° 
As the result of plasmolytic investigations, FLuRI® came to the 
conclusion that salts of aluminum (also of lanthanum and of 
TABLE VII 
ELECTRICAL RESISTANCE OF Laminaria saccharina 
In sea water 300 cc. + 
Time in hours Th (NO;), 0.4 H.O In sea water 
I gm. (=0.006 M) 
Oita keris ban 690 720 
Ogee ee ee PSO rege yy ea eae 
oe esl eae erey ea 7 Lice Gulleeeecthe beeen nihne nger eet tee 
ee Ciena Sia "foo Maeen nape Pusane elnge" Capit seen re 
Bi ay ea a 630 720 
7) oe BES OG ray peice tse Tela Pence |= s 0k aay parton eee oeea heart rye! 
aS NL OIA A ga 540 660 
ADs ies 510 640 
All readings were taken at 18° C. 
800_ OHMS 
_~_iY— 
— 
Ne eee, ay 
600 = 
ig 6 20 30 HOURS 
_ Fic. 7.—Curve of electrical resistance of Laminaria saccharina in sea water 300 CC. 
Th (NO;),-4 H.O 1 gm. (=0.006 M) (unbroken line), and of a control in sea 
water (dotted line). 
yttrium) increase protoplasmic permeability. Sztics? made experi- 
ments on the taking up of dyes by the cell and concluded that 
salts of aluminum decreased the permeability. The experiments 
described show that both effects are produced. Which effect 
predominates depends both on the concentration of the salt (as 
is shown by experiments not mentioned here) and on the length 
of exposure to its action. 
* Flora 99:81. 1908. 7 Sitzungsber. Wiener Akad. 119: 1910. 
