FEBRUARY 9, 1912] 
dantly in milk. These facts correspond with the 
chemical relationships of the sugars, the mono- 
saccharide and disaccharide being most readily 
attacked, next the glucoside, salicin, which breaks 
up into a simple sugar, while the more complex 
carbohydrates are less available. The streptococci 
form a more or less continuous series from those 
which attack no sugar at all to those which fer- 
ment all the carbohydrates tested. Occasionally 
a strain reacts with a substance lower in the series 
of fermentability while failing to do so in a sugar 
usually more available, but this is rare. Charac- 
teristic forms appear in the throat and in the 
feces of man and other animals, so that the method 
promises to prove of practical as well as theoret- 
ical value. 
A Comparison of Streptococci from Milk and 
from the Human Throat: E. C. StTowELL and 
C. M. Hinurarp. 
The present study of throat and milk strepto- 
cocci was undertaken with the object of establish- 
ing a method for distinguishing between organisms 
isolated from the two sources. (The small number 
of strains examined (70) renders any present 
generalizations only tentative.) 
The streptococci used were all isolated from 
fresh specimens in our laboratory by cultural and 
morphological examinations. Quantitative acid 
production was studied in six carbohydrate media; 
dextrose, maltose, lactose, saccharose, raffinose and 
mannite. The tubes were incubated at 37 and at 
20 degrees for 72 hours. The maltose results are 
neglected in the present discussion. 
Below 1.2 per cent. acid production at 37° is 
considered a negative reaction. AJ] but four cul- 
tures on this basis fermented one or more of the 
carbohydrates; 83 per cent. may be placed in 
three groups according to the correlation of their 
‘capacity to ferment the media used. The follow- 
ing table shows this distribution: 
Per Per 
Cent. Cent. 
Throat Milk 
Fermented Cultures Cultures 
Dextrose only ..............-. 22.2 6.3 
Dextrose and lactose ......... 20.4 38.0 
Dextrose, lactose, saccharose ... 33.1 57.7 
Grown at 20° the first reaction mode falls at 
‘0.5 per cent. and on this basis the milk cultures 
fall into the same general groups as shown above, 
but the throat streptococci show 50 per cent. not 
to ferment at all, and 40 per cent. to ferment 
dextrose only. 
SCIENCE 
223 
A comparative study of the cultures isolated 
from sore, inflamed, or otherwise ‘‘abnormal’’ 
throats and from normal throats showed no essen- 
tial differences; the reaction curves follow the 
same general contours throughout. 
(No clue to the relationship of the forms studied 
was obtained from the morphology or staining 
reactions. ) 
Our work leads us to make three preliminary 
conclusions: 
1. Streptococci from the human throat and from 
milk very generally ferment one or more of the 
sugars, dextrose, lactose and saccharose, attacking 
them most readily in the order named. They do 
not generally ferment raffinose or mannite. 
2. The streptococci of the sore and the normal 
throat show no cultural differentiation in relation 
to the carbohydrates used. Virulence tests would 
perhaps have separated the two groups. 
3. Milk streptococci are much more facultative 
than throat strains in relation to the temperature 
at which they are grown. This is, perhaps, the 
most valuable information obtained as a differen- 
tial feature between chained cocci from the two 
sources. 
A Study of Thirty-five Strains of Streptococci 
Isolated from Samples of Milk: Gustav F. 
RUEDIGER. 
The paper points out that Streptococcus lacticus 
can be differentiated from Streptococcus pyogenes 
by means of blood-agar plates. Streptococcus 
pyogenes produces small colonies surrounded by a 
large zone of hemolysis, whereas Streptococcus 
lacticus produces green or grayish colonies with 
very little or no hemolysis. 
Streptococcus lacticus has no sanitary signifi- 
cance, as it is found in nearly all samples of clean, 
soured, or fresh milk, and very often in the 
healthy milk ducts. Streptococcus pyogenes, on 
the other hand, seems to occur but rarely in milk 
and is indicative of the existence of an inflamed 
condition of the udder of the cow furnishing the 
milk. 
A Biometrical Study of Milk Streptococci: JEAN 
BROADHURST. 
This comparative study of carbohydrate fer- 
mentative reactions is based upon streptococci iso- 
lated from milk plates which were made in the 
routine milk examination by the New York De- 
partment of Health. One hundred strains were 
isolated, and as rapidly as purity was assured 
transferred to eight of the Gordon test media: 
