NOTE ON 'PINK-EYE' IN HORSES 205 
was obtained from each specimen. The solid lung and its bronchus gave also a 
number of small colonies which proved to be a streptococcus, but it was without 
effect when inoculated into a guinea-pig. 
Summary. In the above observations we found a small bacillus usually 
growing in pairs on artificial media, which from its reactions and cultures would 
appear to belong to the coli group. The whole respiratory tract of the affected 
animals seem to be infected, but from the fact that animals may die of the disease 
without showing ' pink-eye,' it is probable that the infection starts in the respiratory 
tract, and invades the conjunctiva through the nasal duct. 
This bacillus is usually virulent to guinea-pigs, causing death in two to three 
days. From the fact that it was recovered constantly from the respiratory tract and 
conjunctiva of dead or diseased animals, there is strong presumptive evidence that it 
was the cause of the disease, but we have no experimental proof that it caused the 
typical disease under artificial inoculation. 
The case would appear to be similar to those pathological conditions where 
the B. coli is found to have taken on an increased growth and virulence, as in some 
forms of enteritis. 
