Art. VII.] Weinzirl, Bacteria in Cheese. i6i 
area is included the cheese belt of our country, and although 
the analyses are not as numerous as could be desired, they are 
sufficiently so, to show at least, the main characteristics of the 
cheese flora. In this work 13 species of bacteria were isolated 
and grown in pure cultures. These do not include single colo- 
nies found on the plates, which we are inclined to believe should 
not be considered as forming a part of the true cheese flora, 
but rather as accidental, possibly gaining admmission in the 
manipulation of the analysis. At any rate no special import- 
ance could be attached to such rare colonies, granting that the 
germs may have existed in the cheese. It is conceivable that 
all the bacteria of the air and even of water, might be found in 
cheese, but we do not consider these an integral part of the 
cheese flora proper. 
Of these species, of which the limits of this paper will not 
permit a description, the lactic acid producing germs are found 
to be present in all the analyses, and furthermore are the most 
numerous class in three-fouths of the cheese. The germs pro- 
ducing gas were present in all samples with one exception, 
(No. 1 5) and were most numerous in approximately one-fourth 
of the cheese. In three of these cases (Nos. 6, 10 and 31) 
the preponderance of gas germs was associated with “off flav- 
ors ” in the cheese; in two cases, (Nos. 21 and 22) no note had 
been taken, while in two, (Nos. 7 and 32) the cheese were ap- 
parently fine, one of which (No. 7) had been kept for a num- 
ber of months in cold storage which may have exerted a re- 
pressing influence on the multiplication of the lactic organisms. 
The bacteria affecting the casein of milk were entirely ab- 
sent in one-third of the samples, while the germs of a neutral 
action were present in one-third of the cases. These facts are 
quite in harmony with our former observations, and while not 
as striking in many respects, yet remembering the wide area of 
our field and the varied character and quality of our product, 
the figures are, on a whole, as uniform as could have been ex- 
pected. The presence in relatively small numbers or entire 
absence of the digesting and neutral classes, confirms our con- 
clusion that these play no important function in the cheese and 
