of Carbon Dioxide in Ulva latissima , L. 59 
amount of NaCl during a week’s cultivation in distilled water 
was 21-87 P er cent. Diels concludes that the chloride is 
decomposed within the plant, especially when the NaCl in 
the cell-sap tends to rise beyond a certain definite degree 
of concentration. He connects the decomposition of the 
chloride with the free organic acids, which Kraus 1 and others 
have shown to be present in Halophytes ; probably as a result 
of restricted gaseous exchange, and the defective combustion 
of the carbohydrate. In the Halophytes which Diels experi- 
mented with ( Cakile maritima , Scop., Arenaria ( Honckenya ) 
peploides , L. &c.), malic acid was found to be present ; and 
Diels concluded that possibly the sodium resulting from 
the decomposition of Na Cl united with the organic acid, and 
that sodium malate was formed in the first place from the 
decomposition of the chloride. This latter conclusion is 
admittedly conjectural, and not founded on experimental 
evidence. With regard to the chlorine set free from the 
NaCl, Diels concludes that it unites with the hydrogen of 
the organic acid, and is returned to the exterior by secretion 
of the roots. This would seem to be a most remarkable 
statement, and can only be taken, I think, as showing that 
Diels was unable in any way to trace the ultimate fate of 
the chlorine. 
Hansteen 2 has concluded that NaCl, and also K Cl, stand 
in a definite relation to the formation of proteids from amides 
and carbohydrates. If NaCl is present in a cell capable of 
proteid-formation and of carbon-assimilation, one of two 
things would seem to happen. In the one case, the presence 
of salt tends to prevent the glucose reacting with the 
amide, and the cell remains poor in proteids but rich in 
carbohydrates. The other case seems to present reverse con- 
ditions ; an abnormal acceleration of proteid being formed at 
the expense of the carbohydrate. Hansteen thinks that it 
depends on the quantity of the chloride present which reaction 
takes place. 
In the case of proteid formation it is probable, therefore, 
1 Kraus (’86). 2 Hansteen (’96). 
