172 
Journal of Agricultural Research 
Vol. II, No. 3 
Tabltv I .—Classification of the groups of cheese organisms —Continued 
Streptococcus 
Variety No. 
Production of acidity in broth containing— 
Lactose. 
Sucrose. 
Glycerin. 
Salicin. 
Mannit. 
+ 
zb 
± 
_ 
_ 
b. 
+ 
d- 
zb 
+ 
— 
+ 
+ 
+ 
All organisms which have been found constantly in cheese are included 
in the four groups Bacterium lactis acidi , Streptococcus, and Micro¬ 
coccus groups, together with the B. casei group, which will be discussed 
later. The different varieties of all four groups produce acid in milk. 
Spore-forming organisms occur in very small numbers or are entirely 
absent. The same thing is true of liquefying organisms. Whenever 
they are present in sufficient numbers to have an appreciable influence 
in the ripening, it is to the detriment of good flavor. 
In the classification of the Bacterium lactis acidi group, variety “a” 
corresponds to group “A” in Rogers and Davis's classification of the 
lactic-acid bacteria (1912). Varieties “ b, ” "c” and “d *’ are all included 
in their group “B,” which also includes other varieties which were not 
found among the cheese organisms and are therefore not mentioned in 
this work. 
CONSTANCY OF REACTION OF THE CULTURES OF THE BACTERIUM 
LACTIS ACIDI AND COCCUS GROUPS TO THE TEST SUBSTANCES 
It is obvious that the accuracy of this method, in so far as it is a guide 
for the classification of an individual culture, depends on the constancy 
of the reactions to the tests. It is the opinion of those who have made a 
comprehensive study of this method that the fermentation reactions on 
the test substances are on the whole remarkably constant for any given 
strain, and therefore they are of value in classification. Representative 
cultures of the varieties of the coccus and the Bacterium lactis acidi 
