Mar. E5, 19x4 
Streptococci in Milk 
503 
ACTION ON LITMUS MILK 
Late in the course of the investigation it was noticed that there were 
distinct differences in the action of different cultures on the litmus in 
milk and that this difference was in some relation to the source of the 
cultures. Some cultures decolorized the litmus promptly, leaving a 
white curd, with the exception of a pink ring at the top, which slowly 
extended downward. Other cultures produced a curd which remained 
pink throughout for an indefinite period. This action was recorded for 
the cultures then available, and the results are given in Table IV. It 
will be noticed that while the ability to reduce litmus is characteristic 
of the mouth cultures it is almost entirely lacking in the cultures from 
Fig. 5.—Graphic representation of the characters of cultures of streptococci from milk and from bovine 
feces. 
the udder. The number of cultures in the two other groups in which 
this character was recorded is too small to permit conclusions, but there 
may be observed a tendency in the milk cultures to agree with those 
from the udder. 
TABhF IV .—Distribution of cultures according to action on litmus in milk. 
Cultures recorded from— 
Number 
of 
Cultures reducing 
litmus. 
Cultures 
failing to 
reduce 
litmus. 
cultures. 
Number. 
Percent. 
Milk. 
17 
16 
20 
A 
22. C2 
Per cent . 
76.57 
62. 50 
93. IO 
17 T A 
Feces. 
6 
O' 00 
27 . CO 
Udder. 
2 
Of' O'** 
6.89 
82. 86 
Mouth. 
-y 
35 
20 
