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STUDIES OF MARKET MILK. | 201 
Over 9,000,000 bacteria per cubic centimeter. In the majority 
of tests as shown in this group of tables the germ content aver- 
ages materially higher than was found in the earlier groups 
and the average given in connection with each table represents 
fairly well the general bacterial condition of the milk of the 
given producer. The average percentage of acid organisms in 
this group is considerably higher than was found in the preceding 
groups. ‘This indicates that at least a portion of the increase 
in total germ content is due to the rapid development of the acid 
bacteria in the milk. The dirt content of some of the samples 
. is rather high while on the other hand some of the samples 
were among the cleanest ones found, the average for the group 
being practically the same as for group 2. It is evident from 
this that the increase in bacteria is not due in this case to a 
greater dirt contamination and must, therefore, be attributed 
to the rapid development of the acid bacteria. 
Discussion of group 5.—This group includes the milk from 
those farms where the average germ content was above 2,000,- 
ooo bacteria per cubic centimeter, the milk from eight farms 
exceeded this number and is therefore included in this group. 
This is 26.6 per cent. of the whole number of farms from 
which milk was studied. The smallest average number of 
bacteria for the milk of any of the men included in this group 
is 2,745,000 as shown in Table 47. The lowest test for this 
man is 220,000 on March 23, while his highest test occurred 
on January 1, when his milk contained 19,920,000 bacteria 
per cubic centimeter. The milk of producer No. 30 has the 
highest average bacterial content. The results obtained from 
his milk are given in Table 54, where the average is shown to 
be 19,174,000. The germ content of this milk did not fall 
below 1,000,000 in any test and the highest point was reached 
on October 11, when the milk contained the enormous number 
of over 88,000,000 bacteria per cubic centimeter. ‘This is the 
highest number found in any of the tests. | 
The high percentage of acid producing bacteria found in the 
milk of this group is very noticeable, it being much higher in 
this group than in any of the preceding groups. In individ- 
ual experiments the acid producing organisms not infrequently 
constitute as high as 99 per cent. of all the organisms present 
in the milk. 
14 
