RELATION OF BOVINE TO HUMAN TUBERCULOSIS. 
605 
cular bacillus, yet how often it is that physicians and others 
will write and talk about the dangers of contracting tubercu¬ 
losis by inhaling the tubercular germs that are constantly 
floating in the air in connection with dust, etc. While there is 
no question but what the tubercular bacillus may often be found 
in quite large numbers in the dust of buildings and especially 
rooms that have been, or are, occupied by phthisis patients, it 
is equally true that outdoor air is rarely contaminated with 
these germs. 
If the air is so impregnated with these germs as some would 
lead us to believe, would it not be reasonable to expect that we 
would have more or less wound inoculations in the bovine spe¬ 
cies, for wounds in cattle are very rarely kept antiseptic. And 
if we should get inoculations from this source, and the theory 
is true that the tubercular bacillus always leaves his path of 
entrance to the animal economy strewn with morbid lesions, we 
would certainly have more or less cases of local manifestation 
of the disease in cattle, the same as is sometimes seen in the 
human, and fully 90 per cent, of all adult cattle would thus be¬ 
come inoculated at some time. Yet so far as I know, there is 
not a single case of this kind on record. 
No, gentlemen, when we talk about the constant spread of 
this disease through the inhalation of the germs in the outside 
air, we are simply clinging to the relics of an old, pernicious, 
bygone theory. 
Several theories have been advanced to explain how immo¬ 
bile bacilli gain an entrance to the animal economy, but my 
time will not permit me to discuss this phase of the question, 
further than to say that while none of them have as yet been 
fully substantiated, some recent experiments seem to indicate 
that germs adhering to oil globules, as in meat and milk, may 
be readily taken up by the lacteals. When this point shall 
have been settled, it will undoubtedly clear up some mooted 
questions of to-day. 
I am of the opinion that the tubercular bacillus usually 
enters either the blood of lymph systems as does other germs. 
