390 



INDEX OF BACTERIAL MUTATION 



The results recorded in Table III show a definite difference in acid 

 agglutination optimum of the two varieties. The readings, taken at 

 1,2, and 16 hours, indicate that the reaction does not take place with 

 the speed of that of immune agglutination of the majority of bacteria. 

 It is necessary' to allow ample time to elapse before taking the final 

 readings. 16 hours have been found to be sufificient, no material 

 change in readings being noted after this time. 



The same suspensions were tested against the Na acetate-acetic 

 acid buffer series, with a similar result recorded in Table IV. Tem- 

 perature, as before, was 43°C. in the water bath. 



TABLE IV. 



Acid Agglutination Optimum of Microbes D and G. 

 Na Acetate-Acetic Acid Series. 



The results in the case of the Na acetate-acetic acid series corre- 

 spond to those of the Na lactate-lactic acid mixtures. The final 

 readings are identical, the only difference lying in a slightly more 

 rapid fiocculation in the acetate series. 



Variability of Optimum of Microbe G as Compared to that of 



Microbe D. 



A number of strains were now collected, the D and G types isolated 

 and subjected to test with the Na acetate-acetic acid series. The 

 result (Table V) confirms the findings of the previous experiments. 

 Final reading was made after 16 hours with incubation at 43°C. 

 The results are presented in Table V. 



