INVESTIGATIONS OF ACID ORGANISMS OF MILK. -° 77 
By the results of this second series of experiments the conclu- 
sion drawn from the first set in the previous year was verified 
and emphasized. Milk drawn directly from the cow, at least 
in this stable, never contained the lactic bacteria. All of the 
three common species of lactic organisms are a contamination 
which gets into the milk during the milking or subsequently. 
THIRD SERIES OF EXPERIMENTS. 
It was deemed wise to confirm the results obtained in the 
preceding experiments by a study of the udders of cows, in 
order to demonstrate if possible the presence or absence of any 
of the three common lactic bacteria in the udder. Ward* and 
others have made investigations of a similar character, but 
apparently none of those who have previously made examina- 
tions of cows’ udders have found organisms which agree with 
either of the three known types of lactic bacteria of this region. 
Inasmuch, however, as previous investigators made no especial 
attempt to determine the presence of normal lactic organisms, 
it was thought necessary to repeat the experiments, and, if 
possible, verify their conclusions. If the observations reported 
in the previous part of this paper are correct, we should cer- 
tainly not expect to find the normal lactic bacteria in the udder 
of cows. If, on the other hand, either of the three forms were 
found in the udders, it would manifestly be impossible to obtain 
milk by any normal precautions which would be free from 
lactic germs. 
Only two cows were available for examination in the course 
of these experiments. These two cows were from the same 
herd in which the rest of the experiments had been carried on. 
They had been condemned to slaughter because of reaction to 
tuberculin. Briefly, the study of these two specimens was as 
follows: | 
Cow No. r.—In the case of this cow the autopsy showed the 
presence of no tuberculosis so far as could be seen, but only a 
thrombus of the heart due to a general infection. The udder 
was apparently in a perfectly normal condition, presenting 
neither tubercular lesions nor inflammation. The cow was a 

*N. Y. Cornell Sta. Bul., 178. 
