558 
W. HERBERT LOWE. 
that eat the flesh or drink the milk of tuberculous cows do not 
contract tuberculosis. Whatever in any degree weakens or im¬ 
pairs the system of men or animals renders them more liable to 
the invasion of disease. The animal that inherits a strong-, 
untainted constitution and good health from its progenitors 
possesses a disease-resisting power that often means an immun¬ 
ity. If this principle of heredity was kept in mind in breed¬ 
ing dairy cattle there would not be so much tuberculosis. 
Environment, sanitary conditions, climate and food have of 
course all more or less to do with development of tuberculosis, 
but on this occasion we will confine ourselves to the hereditary 
transmission of weak and .impaired animal bodies from sire and 
dam to offspring which are evidently more susceptible to tuber¬ 
culosis than animals that have inherited plenty of substance and 
stamina. To this phase of the subject I attach a great deal of 
importance, for I believe that it is only by a system of breeding, 
founded on a scientific knowledge of the laws governing hered¬ 
ity, that tuberculosis will be eradicated. The fact that tubercu¬ 
losis is caused by the tubercle bacillus and is therefore not 
hereditary does not lessen the importance of breeding dairy 
cattle having substance and stamina sufficient to resist the de¬ 
velopment of the micro-organism. 
The etiology, diagnosis and pathology of bovine tuberculo¬ 
sis are now well understood by the profession, but when we 
come to take steps to eradicate the disease economic limitations 
and other questions arise. Dr. Salmon, the able Chief of the 
United States Bureau of Animal Industry, estimates that to 
make one inspection and test all the cattle, killing affected ani¬ 
mals, would in the State of Pennsylvania alone cost over five 
million dollars. He suggests a more conservative and less ex¬ 
pensive method by co-operation between the farmer and the 
properly constituted State authorities. Whether the so-called 
radical method or Dr. Salmon’s more conservative method of 
stamping out the disease be adopted, a new crop of the disease 
would soon again appear which would necessitate another in¬ 
spection and further expenditure of money unless something 
