274 MAX LEVINE 



of the sewage strains, while 30.5 per cent from soil and 20.5 per 

 cent from sewage were B. aerogenes. 



B. communior was isolated from all sources as follows: soil 

 14.7 per cent; horse 79 per cent; sheep 72.8 per cent; cow 30 per 

 cent; pig 29 per cent; sewage 7.7 per cent and man 8 per cent. 

 The relative abundance of B. communior among the lower animals 

 and scarcity in man and sewage, may well be investigated further. 



B. neapolitanus was present only in bovine feces and sewage, 

 comprising 20 per cent of the bovine and 7.7 per cent of the 

 sewage strains. 



Of the 9 B. coscoroba, 5 were from sheep, 1 from pig, 2 from 

 sewage, and 1 from man. 22.7 per cent of sheep, 3.2 per cent 

 of pig, 5.1 per cent of sewage and 4 per cent of human strains fall 

 in this species. 



B. coliy like B. communior was isolated from all of the sources 

 tested, but a rather distinct correlation with the source is ob- 

 served with the varieties B. coli-communis and B. coli-immobilis. 

 The former comprise 1.1 per cent of soil; 21 per cent of horse; 



4.5 per cent of sheep; 45 per cent of cow; 35.6 per cent of pig; 



2.6 per cent of sewage; and 20 per cent of human strains. B. coli- 

 immobilis was not obtained from the soil, horse, sheep or cow, but 

 it made up 3.2 per cent of the pig, 30.8 per cent of the sewage, 

 and 20 per cent of the human strains. 



B. acidi-lactici was not obtained from the horse nor sheep, 

 and only rarely from the cow (5. per cent) or soil (4 per cent). 

 The motile variety B. acidi-lactici var. Gruenthali was particularly 

 abundant among the pig cultures (29 per cent) and rare in sewage 

 (5.1 per cent) and man (4 per cent). The non-motile B. acidi- 

 lactici far. immobili Was restricted to man and sewage entirely, 

 comprising 44 per cent of the human and 17.9 per cent of the 

 sewage strains. 



If subsequent and more extensive studies confirm these results 

 the determination of species and varieties would have some bear- 

 ing on the interpretation of the colon test. 



The author takes this opportunity to express his gratitude to 

 Dr. R. E. Buchanan for many helpful suggestions and encour- 

 agement, and to Prof. G. W. Snedecor for assistance and eluci- 

 dation of the mathematical principles involved. 



