92, Commission Report: Tuberculosis. 
placing the reacting animal in the category of recognized cases of 
tuberculosis, which must be reported under a notification law. 
As the newer methods of applying tuberculin for test purposes 
have not been found to be as reliable as the older, subcutaneous 
method, they cannot be advocated. The ophthalmo and cutaneous 
tuberculin tests may have a value in some special cases, as for ex- 
ample, where doubt exists about the reliability of a subcutaneous 
test because an animal may have been subjected to some per- 
nicious manipulation. In this sense these later modes of applying 
tuberculin should be kept in mind. 
IV. EXAMINATION OF MATERIAL FROM CATTLE AND 
HERDS. 
The valuable evidence that may be obtained as to the location of 
tuberculosis through the examination of milk, cream, butter, cen- 
trifuge slime and other products and materials from cattle should 
not be neglected, especially when these examinations are made 
by health officers and others for the protection of public health, 
and are followed up by the inspection of the animals and the 
character of their environment as a routine procedure. Such in- 
spections are constantly becoming more prevalent in various sec- 
tions of the United States and Canada, 
V. MOST IMPORTANT SOURCES OF ANIMAL TUBERCULOSIS. 
Tuberculosis as it exists among the domestic animals of America, 
today, undoubtedly owes its primary introduction to the cattle of 
improved breeding that have been imported from European lands 
from time to time in the past, for the purpose of improving the 
. native stock of the country. No particular breed is to be in- 
criminated in this charge, as several of the most prominent and 
popular breeds have been found guilty of furnishing tuberculous 
individuals to the best American herds on repeated occasions. 
The knowledge that infection has taken place from these sources 
in the past affords us a valuable indicator of the points where 
search should be made in our efforts to detect the cases of tuber- 
culosis that exist to-day upon the farms of the country, First of all 
then, attention may be directed toward all herds of pure bred cattle 
whether of beef or dairy type, especially to those from which cattle 
are sold, either by private or public sale, and from which cattle.are 
