BACTERIA OF THE COLON TYPHOID GROUP 



439 



Bact. coli used, however, three strains died within five, eight and 

 ten days, while the four other strains remained alive until after 

 one month. 



Fate of colon typhoid group on different sugar cultures, inoculated at 87 °C. Numerals 

 signify day of death. Mark — still alive thirty days afterward 



In the above experiments we used 1 or 3 per cent sugar, but the 

 results were almost the same with both concentrations. 



From the results of these experiments we conclude that the 

 recording of sugar fermentation reaction after the organisms 

 are dead is unneceessary. It is desired to observe their activity 

 only during their life. However, we still noticed more or less 

 difference in the amount of the acid or alkali, this variation 

 depending upon the absorption of C0 2 from the atmosphere. 



For instance, in the glucose culture medium for the Bact. typhi 

 and Bact. paratyphi group three to four days will be enough to 

 take the record, then the tubes may be discarded; for Bact. 



