502 
Journal of Agricultural Research 
Vol. I, No. 6 
tinguishing cocci of different species. 1 Stowell, Hilliard, and Schlesinger, 
in the paper already quoted, 2 have pointed out the marked difference 
in this regard between streptococci from milk and those from the human 
throat. In Table III is shown the distribution of cultures according to 
their source and the quantity of acid formed in dextrose broth. This is also 
shown graphically in figure 4. The mode for the culture from the mouth 
falls over 6.5 per cent, while that for the udder organisms is over 5.0 
per cent, and that for those from feces is 5.5 per cent. The mode for each 
group is sharply defined, especially those for the udder and feces groups. 
On the assumption that the cultures obtained from milk may have 
come originally from any of the other sources, we would expect the 
curve representing the milk cultures to spread over the space occupied 
Fig. 4. —Frequency curves showing acid formation in dextrose broth. 
by the other curves. This is true in a general way, but the curve for 
the milk cultures has a mode falling between that for the udder and 
the feces cultures. It should be remembered that the milk cultures 
were not selected promiscuously but from bile tubes incubated at 3 7 0 C. 
Table III .—Distribution of cultures according to the percentage of normal acid pro¬ 
duced in dextrose broth. 
Source. 
I Total number 
of cultures. 
d 
H 
* 
m 
H 
5 
M 
6 
ei 
O 
4 -> 
VI 
w 
V) 
3 
O 
d 
d 
<0 
O 
V> 
ci 
tA, 
to 
0 
q 
to 
q 
4 
0 
to 
10 
4 
0 
q 
4 
q 
3 
m 
4 
in 
3 
O 
in 
q 
'O 
O 
'O 
to 
TO 
»d 
O 
q 
6 
0 
to 
0 
in 
O 
0 
Above 7.5. 
Milk: 
Number . 
I 42 
/ 0 
0 
0 
0 
O 
1 
0 
s 
2 
11 
7 
8 
5 
3 
0 
Per cent . 
\ 0 
0 
0 
0 
O 
2.38 
0 
II. 90 
4 - 76 
26. 19 
16. 67 
19. os 
II. 90 
7 -14 
0 
Udder: 
Number . 
}n 
/ 0 
0 
2 
1 
3 
I 
1 
5 
21 
6 
4 
3 
I 
3 
0 
Per cent . 
l 0 
0 
3-02 
1.96 
5* 88 
1.96 
1.96 
9. 80 
41. l8 
11. 76 
7-84 
5-88 
I.96 
5.88 
0 
Feces: 
Number . 
J-II4 
/ 0 
0 
0 
0 
0 
0 
1 
3 
9 
13 
44 
23 
18 
3 
0 
Per cent . 
l 0 
0 
◦ 
0 
0 
0 
0. 88 
2. 63 
7- S9 
11.40 
38.59 
20.17 
15-79 
2.63 
0 
Mouth: 
Number . 
} 39 
/ 0 
0 
0 
0 
0 
0 
0 
3 
5 
7 
8 
12 
4 
0 
0 
Per cent . 
l 0 
0 
0 
0 
0 
0 
0 
7-69 
12. 82 
:i7-95 
20. 51 
30. 77 
IO. 26 
0 
0 
1 Winslow. C. E. A., and Winslow, Ann e R. Systematic relationships of the Coccaceae. ed. i. 300 p.. 
illus. New York. 1908. 
a Stowell, Hilliard, and Schlesinger. Op. cit. 
