BACTEEIA OF THE COLON TYPE IN HUMAN INTESTINES 239 



procedure consists in growing the bacteria in 10 cc. of 1 per cent 

 Witte pepton, 0.5 per cent K2HPO4, 1 per cent glucose, held in 

 evacuated sealed bulbs for seven days at 30°, collecting the gas 

 by evacuation with mercury pumps and analyzing the gas over 

 mercury. 



The average gas volume and average gas ratio for the 131 low 

 ratio cultures from human feces are shown in table 1 together 

 with the averages found in the grain and bovine feces series. It 





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Fig. 2. Distribution of Cultures According to CO2 : H2 Ratio 



may be noted that the average ratio 1.06 is identical with that 

 found by Keyes and Gillespie when their organisms were culti- 

 vated in a synthetic medium. 



To bring out more clearly the sharp distinction between the 

 high ratio and low ratio groups the distribution of cultures by 

 gas ratios is represented graphically in figure 2. 



The significant characters of the fecal cultures. It is shown in 

 figure 2 that, on the basis of the frequency of occurrence of certain 

 carbon dioxide-hydrogen ratios the cultures are separated into 

 the two distinct groups already observed in cultures from milk, 



