AN UNUSUAL CAUSE OF UDDER DISEASE. 
31 
membrane. In a few cases the mouth of the teat canal was more 
or less closed by a scab of dried exudate or milk, and in several 
others the first stream of milk was divided or deflected from the 
normal direction, all pointing- to the presence of a catarrhal con¬ 
dition of the membrane lining the teat canal and, perhaps, also of 
the mucous membrane of the cistern. In one cow pressure on 
the end of the teat forced a drop of mucous from the opening of 
the teat canal. There were twelve cows, which were among the 
first affected, in which a thickening of the mucous membrane of 
the cistern could be detected, and in several of them there was 
also induration of the lower part of the gland tissue—evidences 
of the connective tissue formation associated with chronic inflam¬ 
mation. 
These alterations are symptoms of catarrhal mastitis, in which 
disease there is a similar change in the milk, and the gradual 
spread of the condition through the herd suggested the presence 
of the streptococcic, contagious form of catarrhal mastitis. But 
the milk from the herd had been examined once a week by a bac¬ 
teriologist, and not only had no streptococci been found, but at 
several of the examinations made during the prevalence of the 
trouble the bacterial count was lower than usual, as is shown by 
the Table B, given below. Moreover, the distribution of the af¬ 
fected cows through the herd was not such as to indicate trans¬ 
mission of the infection in milking. Samples of milk were taken 
from three cows in different'stages of the condition, centrifuged, 
and the sediment examined microscopically, and the mucus 
pressed out of the teat opening of the cow mentioned above was 
also examined miscroseopically, but no streptococci could be 
found and very few leucocytes. Very few bacteria or cells or any 
kind were present. These samples were centrifuged on the farm 
with a hand centrifuge for urine and blood work, but the results 
were subsequently confirmed by the examination of these samples 
of milk in the milk hygiene laboratory of the Veterinary School, 
in which work I wish to acknowledge the co-operation of Dr. H. 
C. Campbell.. These three samples were altered in different de¬ 
grees, No. i showing small flakes. No. 2 larger flakes and more 
