COMPARATIVE STUDIES ON RESPIRATION. 



IX. The Epfects of Antagonistic Salts on the Respiration of 



Aspergillus niger. 



By F. G. GUSTAFSON. 

 {From the Laboratory of Plant Physiology, Harvard University, Cambridge.) 



(Received for publication, July 21, 1919.) 



The relation of antagonistic salts to the respiration of higher fungi 

 has received no attention. As the problems involved are of consid- 

 erable interest the writer has made a beginning in this direction by 

 conducting a series of experiments on Aspergillus niger. 



It may be of interest to compare the results with those obtained on 

 other organisms. 



In experiments on sea urchin eggs Warburg^ and Meyerhof^ found 

 that NaCl causes a rise in respiration which is inhibited by the ad- 

 dition of CaCl2. Loeb and Wasteneys^ found no such rise. The 

 results with Aspergillus show a rise with lower concentrations of NaCl 

 and a fall with higher concentrations. Since the highest rise in NaCl 

 (24 per cent) is very small as compared with the rise of several hun- 

 dred 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 concen- 

 trations of NaCl and CaCl2 and a decrease in higher concentrations. 

 A mixture of NaCl and CaCl2 shows antagonism. 



In some experiments on Aspergillus niger Kosinski^ tested the effect 

 of NaCl; although he seems to think that a 1.523 per cent (0.26m) 



^ For a summary of the experiments on sea urchin eggs see Osterhout, W. J. V., 

 J. Gen. Physiol, 1919-20, ii, 1. 



" Brooks, M. M., /. Gen. Physiol, 1919-20, ii, 5. 

 2 Kosinski, I., Jahrb. wiss. Bol, 1902, xxxvii, 154. 



17 



