16 



MAX LEVINE 



rose are well correlated. Colon-bacilli-like organisms which form gas, 

 also give rise to acid and vice versa. Among the gas-formers 2 groups 

 are apparent; one forms acetylmethylcarbinol from glucose (V.P.+) 

 and a relatively large amount of acid from sucrose (mode at 1.50% 

 normal), while the other does not form acetylmethylcarbinol from 

 glucose (V.P. ) and gives rise to a much smaller quantity of acid 

 from sucrose (an extremely sharp and distinct mode at 0.70% 

 normal). 



MacConkey Types I and II do not form acid from sucrose. That 

 Types III and IV are indistinguishable on the basis of quantitative 

 acid-production in sucrose, is apparent from Table 6. 



Ten of the organisms from cow, 15 from horse, 20 from sheep, 10 

 from pig, and only 3 from man, ferment sucrose. The amount of acid 

 formed bears no definite relation to the animal source, but it should 



TABLE 6 



RELATION OF SOURCE, MACCONKEY TYPE, AND VOGES-PROSKAUER REACTION TO ACID-PRODUCTION 



IN SUCROSE 



be noted that a few cultures among the horse strains form considerably 

 more acid than any of the other animal strains. The high average for 



