190 STORRS AGRICULTURAL EXPERIMENT STATION. 
but while the percentage of acid organisms bears no close re- 
lation to the length of time which the milk will keep there does 
exist a fairly uniform relation between the percentage of acid 
bacteria and the amount of dirt which the milk contains. A 
study of these tables reveals the fact that a high dirt content 
normally goes with a high percentage of acid bacteria while a 
low dirt content is commonly accompanied by a low percentage 
of acid organisms. . While this relation is not always uniform 
and while many exceptions may be found, this seems to be a 
moral condition. This condition is what would naturally be 
expected since the acid organisms which commonly sour milk 
are introduced from external sources with the dirt and dust 
which gain access to the milk. It is very natural, therefore, 
that a fairly uniform relation should exist between the amount 
of dirt and the percentage of acid organisms contained in the 
milk. It must be borne in mind that a portion of the dirt 
contamination of the milk had gone into solution and does not » 
appear in the figures representing the relative dirt content in 
these tables. It is probable that the relation between the dirt 
content and the percentage of acid organisms would be more 
uniform if the actual total dirt contamination were determined. 
While it is not the purpose of this article to discuss the condi- 
tions under which the milk was produced, it may be said here 
that the stable conditions bear a fairly direct relation to the 
amount of dirt and the numbers of bacteria found in the milk 
of the different producers. The construction of some of the 
stables is fairly good and with more care in the management a 
much better quality of milk might be produced. A few of the 
stables in this group were of rather bad construction for the 
purpose of producing a good grade of milk. __ 
Discussion of group 3.— ‘This group contains the milk from 
those farms where the germ content for the entire series of | 
tests was between 500,000 and 1,000,000 bacteria per cubic 
centimeter. The milk of but two producers comes in this 
group. ‘The principal difference between the milk given in 
these tables and that given in the preceding group of tables 
lies in the greater germ content. It will be seen in Table 38 
in the column marked ‘‘ Total bacteria’’ that the variation 
from day to day is very marked. ‘The lowest number which 


