Organisms of Sanitary Significance on Grains 209 



Wright^ to be present in the intestine of many groups of animals. 

 More recently a number of investigators in PLurope and America 

 have reported that bacilli in all respects like the colon bacillus from 

 the human intestine, are found in nature where there is no evidence 

 of recent or direct fecal contamination. Kruse*^ and Weissenfeld^ 

 declared that B. coli is present in almost all v^^aters, good or bad. 



In 1901 one of us^-^ isolated from grains and products of milling 

 a considerable number of organisms having all the characteristics 

 of B. coli, and Papasotiriu'° obtained the same results in Europe 

 in an investigation of similar scope. Other workers have also pub- 

 lished results which lead to the conclusion that organisms presenting 

 the characteristics of B. coli are by no means confined to the intes- 

 tinal tract of animals, but are widely distributed in nature. 



Investigations on the occurrence of B. coli on plants, either 

 healthy or diseased, have been made by Gordan," Laurent," and 

 Klein and Houston. '^ The last-named workers examined grains 

 and many food substances for B. coli, and although a large number 

 of samples were studied, negative results were obtained in most 

 cases, and it was concluded that B. coli was not present on the grains 

 or in the products of milling. All these cultures were isolated after 

 a prolonged preliminary cultivation, generally three days or more, 

 in phenol broth or phenol gelatin — a treatment which we have found 

 generally causes the colon bacillus to be killed out to a large extent, 

 if continued for more than eight hours, and which therefore may 

 explain in part their negative results. 



In order to make more certain that the organisms found on grain 

 were not merely bacteria having some of the more striking char- 

 acteristics of B. coli, we undertook in 1902 a careful comparison of 

 cultures derived from the human intestine and from grains. The 

 results of this investigation are embodied in this paper. 



In the autumn and winter of 1904 one of us (E. G. S.)'^ studied 

 the organisms occurring on the heads of grain left standing in fields 

 far removed from the sources of pollution with fecal matter, and 

 a little later Metcalfe conducted an investigation of the flowers 

 and grains from rice-fields in South Carolina, but where evidences 

 of contamination were not entirely absent. 



The investigation of the occurrence of streptococci was lx*gun 



