go REPORT OF DEPARTMENT OF BACTERIOLOGY OF THE 
siderable numbers while Bact. 212.33300 was found in Cheese 4.6 
III. The latter is probably not an active form in connection with 
cheese-ripening processes as it neither attacks sugar nor produces 
digesting enzyms. Bact. 222.11100 was also isolated from Cheese 
4.6 IV. It is not considered active in the ripening of cheese be- 
cause it is never found in any considerable quantities in a first-class 
article. It is a vigorous gas former, is not found in clean milk 
and is inhibited by the cheese-making process. 
Soon after the milk was put into the vat signs of gas produc- 
tion began to manifest themselves but were soon suppressed and 
the resulting curd was free from gas holes. Coincident with gas 
production two species of gas-producing bacteria were found in 
the milk and cheese. B. coli aerogenes, B. 222.11100, was found 
in the first sample only and in very small numbers. Bact. lactis 
aerogenes, Bact. 222.11100, made up about 10 per ct. of the flora 
of the first three samples. 
The results from this cheese accord with the idea that aside from 
the lactic group there is no single group or at least no single species 
of bacteria absolutely essential to the ripening process. It must 
be admitted, however, that the ripening of Cheese 4.6 VIII was 
neither so rapid nor so satisfactory as might be desired. 
Quantitative results— Plates were made upon media 2.22, 2.02 
and 2.31 for the purpose of determining the total flora, the lique- 
fiers and the yeasts respectively. The results of these examinations 
are given in Table XVI. 
