Comparative Studies on Respiration. Ix. the Effects of Antagonistic Salts on the Respiration of Aspergillus Niger

The relation of antagonistic salts to the respiration of higher fungi has received no attention. As the problems involved are of considerable interest the writer has made a beginning in this direction by conducting a series of experiments on Aspergillus niger. I t may be of interest to compare the results with those obtained on other organisms. In experiments on sea urchin eggs Warburg I and Meyerhofl found that NaC1 causes a rise in respiration which is inhibited by the addition of CaC12. Loeb and Wasteneys ~ found no such rise. The results with Aspergillus show a rise with lower concentrations of NaC1 and a fall with higher concentrations. Since the highest rise in NaC1 (24 per cent) is very small as compared with the rise of several hundred per cent obtained by Warburg and by Meyerhof, the results as a whole agree much more nearly with those of Loeb and Wasteneys. Still closer agreement is found in the results of Brooks, ~ who has used both sodium and calcium in studies on the respiration of bacteria. She finds an increase in the rate of respiration with certain concentrations of NaC1 and CaC12 and a decrease in higher concentrations. A mixture of NaC1 and CaCI~ shows antagonism. In some experiments on Aspergillus niger KosinskP tested the effect of NaC1; although he seems to think that a 1.523 per cent (0.26M)