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I4 STORRS AGRICULTURAL EXPERIMENT STATION. 
them out with any degree of satisfaction. It is exceedingly 
dificult to determine the types of bacteria in a culture contain- 
ing so many millions of organisms per cubic centimeter as are 
found in ordinary cream. The work involved is excessive and 
the results obtained seem to be rather small. The experiments. 
which formed the basis of this article have occupied a consid- 
erable portion of the time for three years in the bacteriological 
work in this laboratory. But although they have been ex-. 
tended over such a long period, the results are not yet wholly 
satisfactory. The experiments particularly described below 
number about forty, but this represents only a very small part: 
of the total number. The early experiments were of use only 
in suggesting problems and in pointing out methods of work, 
and inasmuch as they were of no especial significance in the 
general result, because of imperfect methods, they have been 
wholly omitted from our descriptions. After a moderately 
satisfactory method was determined further tests of cream 
were made in large numbers, and they have yielded quite 
constant results, with certain exceptions, which will be noted. 
The constancy of these results, which have been obtained now 
in two score or more of similar experiments, leads to the con- 
clusion that, in spite of the necessary imperfection of the- 
method, the results may be relied upon as expressing approxi- 
mately the truth in regard to the problem studied. It should. 
be added that the methods that are employed are being con- 
stantly improved, and at the present time a greater accuracy 
is possible than in the earlier part of the work. ‘The experi- 
ments are still going on and will be continued for some time. 
longer, but it has been deemed wise to publish at this time the 
general result of the work of the last three years upon this. 
subject. : . 
The significance of this series of experiments may be under- 
stodd from another consideration. As is well known, there 
have been put upon the markets in the last ten years quite a 
large number of pure cultures for cream ripening, some of 
which have been used very widely. In the countries of north- 
ern Europe the use of such pure. cultures has rapidly extended, 
and in Denmark it is practically universal. But although quite. 
a number of such cultures have been used, there is no one of 
them which produces results that are wholly satisfactory, at 

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