AEROBIC SPORE-BEARING NON-PATHOGENIC BACTERIA 283 



mentioned above another series of milks, also subjected to vari- 

 ous treatments, was investigated with the object of testing the 

 preliminary classification adopted. In this second portion of 

 our work the types previously established were abundantly 

 confirmed but no new organisms were isolated. We believe 

 therefore that the organisms first worked out represent the spore- 

 bearing organisms usually present in Baltimore milk. Our 

 original 250 cultures show the various species in the following 

 proportions. 



Baltimore Milk 



Bacillus cereus Frankland 124 



Bacillus subtilis (Ehrenberg) Cohn 79 



Bacillus alholactus Migula 25 



Bacillus vulgatus (Fliigge) Trevisan 15 



{Bacillus mesentericus vulgatus Fliigge.) 



Bacillus mesentericus (Fliigge) Migula 2 



(Bacillus mesentericus fuscus Fliigge.) 



Bacillus fusiformis Gottheil 2 



Bacillus petasites Gottheil 1 



Bacillus cohaerens Gottheil 1 



Bacillus terminalis Migula 1 



In addition to these the following species were isolated from 

 other sources during the work on milk and made the basis for 

 comparison. We have reason to believe that they may occur 

 in milk, partly from the work of others and partly because they 

 are not infrequent in milk products. We introduce them here 

 for completeness. 



Bacillus mycoides Fliigge. 



Bacillus megatherium De Bary. 



Bacillus simplex Gottheil. 



Bacillus aterrimus Lehmann & Neumann (Bacillus mesentericus 

 niger Lunt). 



Bacillus niger Migula (Bacillus lactis niger Gorini) . 



Bacillus globigii Migula. (Bacillus mesentericus ruber Globig). 



Finally a brief note is added in regard to certain other cul- 



