26 
BULLETIN 739, U. S. DEPARTMENT OF AGRICULTURE. 
Table 14. — Influence of conditions of production on the subsequent increase of organisms 
of the colon-aerogenes group — Continued. 
Total 
Colon count. 
Sample 
No. 
Conditions. 
count in 
fresh 
Held 6 
hours at 
86° F. 
(30° C). 
Held 24 hours at— 
milk. 
FTesh. 
50° F. . 86° F. 
(10° C). , (30° C). 
1 
f 670, 000 
100 
200 
; 260,000,000 
2 
820,000 

2,100 
ioo i 117,000:000 
3 
3,300,000 
1,200 
35,200 
1,400 | 342,000,000 
4 
1.800,000 
100 
3,100 
200 1 240,000;000 
5 
1, 170', 000 

400 
181,000,000 
6 
1,440,000 

700 
200 159,000,000 
7 
620,000 
100 
( l "i 
300 
1,850,000 
8 
860,000 
300 
0) 
500 
194,000.000 
9 
10 
11 
Barn dirty, cleaned twice a week: 
utensils washed after 8 hours but not 
sterilized. 
570,000 
630,000 
1,300,000 
800 
300 
600 
1,500 
9.700 
1,400 
CO 
C 1 ) 
800 
120,000.000 
162.000.000 
72; 000, 000 
12 
2,720,000 
1,800 
510.000 
3,300 
285,000.000 
13 
I) 120, 000 

'600 

96,000.000 
14 
1,840,000 
900 
14.200 
1,200 
330.000.000 
15 
1.080,000 
1,100 
4,500 
1,500 460;0O0,0O0 
16 
i;92o;ooo 
1,300 
4,300 
2,700 370,000.000 
17 
1,160,000 
100 
100 
i;300 160,000.000 
18 
3.820,000, 
1,100 
12,400 
21,000 196,000,000 
19 
2,200.000' 
600 
0) 
(i) 115, OOO; 000 
20 
4,300,000 
1,500 
0) 
(i) 220,000,000 
Av( 
jrage 
1,667,000 
595 
37, 525 
2,156 2(U. 875.000 
No determinations made. 
The results of these experiments in general confirm the opinion of 
Race (13) that organisms of the colon-aerogenes group do not grow 
at 45° F. (7.2° C), for as a rule little or no growth was found to take 
place when milk was held at 50° F. (10° C.) for lengths of time com- 
parable with commercial practice. 
In studying the growth of organisms of the colon-aerogenes group 
in milk held at different temperatures, yj^ of a cubic centimeter 
was the largest quantity of milk examined, so that any growth 
occurring in quantities less than 100 per cubic centimeter would not 
have been detected. The results obtained therefore do not conflict 
with those of Prescott (12), who found that milk which showed no 
colon bacilli in a single cubic centimeter when fresh, after 24 hours 
at 50° F. (10° C.) contained from 10 to 50 per cubic centimeter. 
When milk is kept at temperatures above 50° F. (10° C.) there 
is a rapid growth of organisms in the colon-aerogenes group xn direct 
proportion to the temperature and time to which milk might be sub- 
jected under commercial conditions. 
