1915] CURRENT LITERATURE 415 
liberated and becomes available for the neutralization of the accumulated acid 
when through want of a carbon nutrient rapid growth is no longer possible. 
KreseEt’ has examined a large number of acids, mostly organic, and salts 
of some inorganic acids with reference to their toxicity to Aspergillus niger. 
The numerous data which do not permit of any brief generalizations are, like 
other data of this kind, of interest more from a toxicological than from a 
physiological standpoint. The author’s conclusion that the toxicity of organic 
acids cannot be entirely ascribed to the dissociated part of the molecule is in 
accordance with the findings of other investigators. The mode of action of 
the dissociated part of the molecule has not thus far been explained. The 
author’s hypothesis, that toxic action which cannot be correlated with chemical 
Properties is associated with the degree of permeability of the protoplasm to 
the substances exerting such ta is interesting ot io light of the researches 
of Myer and of OVERTON, but ks nce, for it has not been 
shown on the one hand that ick and power to penetrate the protoplast 
go hand in hand in such cases, and on the other hand it is self-evident that 
substances which do penetrate the protoplast cannot act as poisons. The 
author fails to find a regulatory depression of acidity of the medium, as has 
been reported by some investigators. With regard to the relative toxicity 
of the chlor-acetic acids, Kreset’s results harmonize with those of CLarK, 
who found that the introduction of one or two chlorine atoms into acetic acid 
increased its toxicity, but the introduction of a third chlorine atom lowered the 
toxicity. 
The problem of antidotal action, or antagonism of one substance toward 
another, assumes special significance in the study of the toxicity of various 
substances to fungi, since the toxic substances whose effects are to be studied 
can rarely be used alone, but must usually be combined with other electrolytes 
or non-electrolytes requisite for the growth of mycelium and in most cases even 
for the germination of spores. Several papers dealing with this problem have 
appeared recently. 
From this point of view BorsEKEN and WaTERMAN? have studied the 
influence of a series of substances on the toxicity of boracic acid toward Penicil- 
lium glaucum and Aspergillus niger. The substances studied were inated 
sorbite, dulcite, mannite, arabinose, xylose, glucose, levulose, mannose, rham- 
nose, galactose, maltose, lactose, raffinose, sucrose, p-oxybenzoic iad: pro- 
boeatechuic acid, and gallic acid. Definite pucontcatons (usually 2 per cent) 
of these substances were used in connection with varying concentrations 
of the acid. The culture solutions were made with tap water, to which 
Kre ., Recherches sur l’action de divers acides et sels acides sur le dével- 
Oppement rg “seater niger. Ann. Inst. Pasteur 27:391-420. I913. — 
9 BOESEKEN, J., and WaTerMAN, H. J., Uber die wirkung der Borsiure und 
einiger anderen Verbindungen auf die Entwicklung von Penicillium glaucum und 
Aspergillus niger. Fl. Microbiologica 1:342-358- 1912 
