136 
HAROLD C. ERNST. 
with no definite lesion of the udder may contain the infec¬ 
tious principle of tuberculosis, if the disease be present in 
other portions of the body of the animal. Also, that this 
presence of the infectious principle is not merely a scientific 
possibility but an actual probability , which we should be thor¬ 
oughly aware of and alive to. 
Other interesting facts shown are these: that the cream 
after rising is quite as likely to be infectious as the milk, be¬ 
cause the bacilli were found in the milk nine times after the 
cream had risen, and in the cream eight times after it had sep¬ 
arated from the milk. 
In regard to the constancy of the occurrence of the bacilli 
in the milk, in two of the ten cows in whose milk the bacilli 
were found, but one sample of the milk was examined ; and 
the bacilli were found in one sample out of several examined 
at different times, in two cases. In the remaining six cows, 
bacilli were found two or more times in different samples of 
milk. So that, as far as they go, these results seem to indicate 
that the bacilli are present with a fair degree of constancy. 
At the same time it should not be surprising if one examina¬ 
tion was successful and others failed, because of the chances 
against success, owing to dilution, which were spoken of 
above. 
In nine of the seventeen cases the time of the milking and 
the portion of the milk used were noted; that is to say, a 
sample was taken from the first of the milking, or the last of 
the milking, and then cover glasses made from the milk or 
cream. In these cases bacilli were found in the cream three 
times, and in the milk four times, from the first of the milking; 
in samples from the last of the milking, in the cream no times 
and imthe milk four times ; and this too seems to show an 
interesting point, viz., that the bacilli, if present at all in the 
udder, are not washed out entirely by the first manipulations 
of the teats, but may be supposedly present in any portion of 
the milk. The converse is also indicated, that the manipula¬ 
tion of the udder in the process of milking does not express 
the bacilli from the tissue into the latter portion of the milk, 
but that, as before, they may be supposed to be pretty evenly 
