73 



Recent observations by Rogers and his associates, Darling, Chen and 

 Rettger, Stokes, and others are entirely in accord with the opinions recorded 

 that the aerogenes section is rare in feces of man and animals. 



The relative presence of the coli and the 'aerogenes sections in human 

 and various animal feces is shown in Tables XXXVI. and XXXVII. 



TABLE XXXVII. INCIDENCE OF AEROGENES TYPES AMONG COLON BACILLI 



IN ANIMAL DEJECTA. 



* Single samples from each species. 



Incidence of the Coli and Aerogenes Sections on Grains and 

 in Soil. Many investigators have reported the presence of the colon 

 group on grains and plants. Prescott found lactose -fermenting bacteria 

 in flour, bran, corn meal, oats, and barley. Similar observations were 

 made by Papasotiriu in Germany. Cline and Houston found, what they 

 regarded typical colon baccili, in 3 out of 24 samples of wheat, oats, rice, 

 etc. Bettencourt and Borges (1908) succeeded in isolating such organ- 

 isms from vegetables and cereals. Konrich (1910) frequently observed 

 the colon group on cultivated plants and that even about six percent of 

 plants obtained from waste places showed colon bacilli. Fifty-five percent 

 of 300 samples of grain showed members of the colon group. 



These investigators, however, did not differentiate between the Bact. 

 coli and Bact. aerogenes. Rogers, Clark, and Evans were the first to point 

 out that the colon-like forms, occurring on grains, were distinctly dif- 

 ferent from those observed in feces. They isolated 166 cultures from 

 33 samples of dried grains and 2 samples of green oats. Of these only 

 8 (4.8%) were the low ratio (coli section); (91.0%) were of the 



