382 



PHYSIOLOGY OF BACTERIA 



there is scarcely any death for four days if cells are 

 kept in a well balanced salt solution. This makes it 

 very clear that in most of the experiments mentioned 

 before, death was not really caused by starvation. 



It should be emphasized here that Zeug always made 

 parallel experiments in plain distilled water and in 

 doubly distilled water; viability was greatly prolonged 

 by the second distillation. 



Here also should be mentioned the experiments of 

 Wilson (1922) on the viability of Bact. suipestifer in 

 Ringers solution (600 mg. NaCl, 75 mg. KCl, 100 mg. 

 CaCl2, 100 mg. K2CO, 1 liter H2O). There was little 



difference between the death rates in the original solu- 

 tion and in different dilutions, as far as 1 part Ringer 

 solution + 15 parts of water. 



Winslow and Brooke (1927) verified the results of Zeug's studies. 

 Different bacteria were washed from agar slants into distilled water, 

 centrifuged, resuspended in fresh distilled water, and recentrifuged. 



