70 STORRS AGRICULTURAL EXPERIMENT STATION. 
contamination entering the milk during or after the milking. 
This experiment was performed with a single cow, No. 81. 
The milk of this cow was drawn into a two-quart sterile pail, 
2%4 minutes being required for milking. At the same time 
samples of milk were drawn into sterile glass tubes holding ; 
10 cc., in such a way as to prevent as much as possible any 
contamination from external sources. These tubes had a very 
small opening and were quickly plugged with cotton after the 
milk was drawn. ‘The milk from these sample tubes was 
plated in gelatin and carefully examined for the presence of 
acid organisms, but none were found. ‘The milk drawn in the 
pail was allowed to stand until the cream separated, and then 
examination was made of the cream. ‘This showed an average 
of 161,000,000 organisms per ce. Of these about 50 per cent. 
were B&B. acidi lactict, 20 per cent. B. actdi lactict L., 5 per cent. 
B. lactis aerogenes, and the remainder consisted of miscellaneous 
bacteria. "This same cream was tested after a more complete 
ripening (39 hours) and found to contain 268,000,000 bacteria 
per ce., of which 85 per cent. were B. actdi lactict, the other 
lactic organisms having decreased proportionately. This exper- 
iment evidently indicates that the milk became contaminated 
with acid organisms either during or after milking, but appar- 
ently did not contain them when freshly drawn. 
Experiment No, 2.—This experiment was confirmatory of 
the first, but was conducted on a slightly different plan. A 
different cow was chosen, No. 50. Milk was drawn into sterile 
tubes as before, and also into a tall sterilized jar which had a 
comparatively narrow mouth, the chief difference between this 
experiment and the last being in the size of the opening of this 
jar as compared with the pail used in the previous experiment. 
Bacteriological examination of the samples in tubes were made 
at once and showed an average of 500 organisms per cc., but 
none of the three species of lactic organisms were present. 
‘The milk in these tubes did not curdle in 28 days, but remained 
sweet and palatable for this length of time. ‘The milk in the 
jar, which was closed by a cotton plug, was allowed to stand 
until the cream had arisen, and then a bacteriological exam- 
ination was made of the cream. ‘This cream showed at first 
600,000 organisms per cc. When partially ripened 68,000,000 


