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been infected from bovine sources. Ravenel reports that of 5 cases 
of tuberculosis in children 2 received their infection from cattle. 
Theobald Smith has also reported on one culture of the bovine tuber- 
cle bacillus obtained from the mesenteric glands of a child out of 5 
cases examined, and according to a recent paper by Goodale, Smith 
has recently been at work on 7 other cultures from different children, 
4 of which conformed to his idea of tubercle bacilli emanating from 
cattle. Of 4 cases of generalized tuberculosis in children examined 
in the Biochemic Division of the Bureau of Animal Industry, 2 were 
found to be affected with very virulent organisms, which warranted 
the conclusion that such children had been infected from a bovine 
source. The Pathological Division of the same Bureau has likewise, 
out of the 9 cases of infantile tuberculosis examined, obtained two 
cultures of tubercle bacilli that could not be differentiated from bovine 
cultures. In Europe so many similar instances of bovine tubercle 
bacilli having been recovered from human tissues are on record that it 
appears entirely proven that man is susceptible to tuberculosis caused 
by animal infections, and while the proportion of such cases can not 
be decided with even approximate accuracy, it is nevertheless incum- 
bent upon us to recommend such measures as will guard against these 
sources of danger when enforced. 
The two principal sources of infection from cattle, and the only ones 
necessary to be considered, are the meat and milk of tuberculous 
animals. The fact that most of the cases of bovine tuberculosis above 
enumerated which occurred in the human were cases of infantile 
tuberculosis points with grave suspicion to the milk rather than the 
meat supply. This naturally leads to the question of how and under 
what condition does the milk become dangerous, since Bang, Rabino- 
witsch and Kempner, Ernst, Ravenel, Smith, MacWeeney, Moussu, 
Gehrmann and Evans, Mohler, and many others have definitely deter- 
mined the infectiveness of milk from tuberculous cows. 
That milk coming from a tuberculous udder is capable of trans- 
mitting the infectious principle is conceded by all who have given the 
subject any consideration. It has been equally established that in 
advanced generalized tuberculosis the udder may secrete tubercle 
bacilli without showing any indication of being affected. Careful 
experiments performed by trained and eminently responsible inves- 
tigators have also demonstrated beyond reasonable doubt that tuber- 
cle bacilli at certain times may be present in the milk of cows affected 
with tuberculosis to a degree that can be detected only by the tuber- 
culin, test, so that in a herd of cows in the various stages of tuber- 
culosis it is to be expected that some of them will secrete tuberculous 
milk, which, when mixed with other cows’ milk, makes the entire 
product dangerous. 
