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BACTERIA IN THE DAIRY. 67 
striking, and no one failed to perceive the marked disagreeable 
flavor. The total result of these experiments, however, has been to 
indicate that the effect upon the flavor of butter, while noticeable, 
is not so striking as was at the outset expected. Atthesame time 
the effect was sufficient to make the differences between the fine, 
delicately flavored butter and the unpleasant, strong-tasting 
butter which results from an improper ripening; in other words, 
the differences between the very highest quality of butter and 
that of an inferior grade. 
Another point of much significance was noted. Of the large 
variety of species of bacteria found in ripening cream the number 
which produce poor butter is very small. Among the 20 species 
already experimented with, only three produced strikingly bad 
effects, while all the rest gave good butter or had no marked in- 
fluence. This is a matter of considerable importance as bearing 
upon dairy interests. It indicates that no particular species of 
bacteria is needed to produce a good aroma, but that nearly all of 
the species liable to get into the cream under normal conditions, 
_ will give moderately good results. Some, indeed, are better than 
others for the purpose, and some really produce injurious effects, 
but the majority of species are either directly advantageous or 
neutral in their action. It must be remembered, however, that 
the source of these organisms was cream from first-class cream- 
eries, where the beneficial species must be supposed to outnum- 
- ber the injurious ones. YWhat result would have been obtained 
if a lot of cream from an inferior dairy had been used as a starting 
point, cannot be stated, but the result remains that good condi- 
tions may be depended upon to produce favorable varieties of . 
bacteria in abundance. 
Somewhat akin to the above is the general observation that no 
single species produced a typical ripening of cream, or the 
usually expected flavor in the butter. Although many of them pro- 
duced excellent butter, yet in every case the verdict would be given 
that the flavor was not exactly that of normally ripened butter. 
This is not to be wondered at, for it is hardly to be expected that 
any one species would produce the same result as that produced 
by many species growing together. yExperiments with combina- 
tions of species have therefore been undertaken, but the results 
are not yet complete. 
It will be noticed that most of the species experimented with, 
produced an alkaline reaction, the reason being that a large part 
