AEROBIC SPORE-BEARING NON-PATHOGENIC BACTERIA 515 



while the other organisms mentioned are extremely rare. The 

 conclusions reached by the study of the total number of organ- 

 isms are borne out by the analysis of the individual samples 

 which may be tabulated as follows: 



B. cereus 



B. petasites 



B. mycoides 



B. megatherium 



B. subtilis 



B. vulgatus 



B. mesentericus 



B. cohaerens 



B. fusiformis 



B. agri 



B. simplex 



B. cereus var. fluorescens . 

 B. mesentericus var. flavus 

 B. brevis 



Total 



BALTIMORE SERIES 



16 



10 

 5 

 4 

 2 

 1 



39 



20 



18 



6 



6 



4 



57 



23 



15 



3 



8 

 3 

 4 

 2 



60 



17 



21 

 1 

 8 

 7 

 4 

 6 

 1 



66 



58 

 9 



84 



NAZARETH SERIES 



20 



3 



1 

 2 



35 



10 

 30 



4 



4 



67 



23 

 66 

 2 

 6 

 4 

 2 

 3 

 1 

 2 



112 



Source of samples: 1, Paving sand, Baltimore City; 2, surface soil, lawn of 

 Johns Hopkins Hospital ; 3, soil from fertilized flower bed, Baltimore City, under 

 cultivation, 20 years; 4, soil from cultivated garden, Baltimore; 5, soil from 

 field, suburb of Baltimore; 6, clay from depth of 5 feet, Nazareth; 7, soil from 

 highly fertilized garden, under cultivation more than 25 years; 8, richly fertilized 

 field soil. 



In the Nazareth series the predominant organism was Bacillus 

 petasites which made up more than half the isolations. Bacillus 

 cereus stood next while Bacillus mycoides was obtained on but 

 two occasions. The analysis of the individual samples shows the 

 same predominance of Bacillus -petasites and is chiefly interesting 

 in demonstrating the small number of organisms isolated from 

 soil collected at the depth of five feet as contrasted with the 

 more diversified flora of highly fertiUzed top garden and field 

 soil. 



In general it may be seen that the study of soil confirms the 

 conclusions reached by the study of milk, dust and water. The 



