STREPTOCOCCI IN COMPARATIVE PATHOLOGY. 
781 
tents of the different lesions can be considered indicative of the 
nature of the bacterial invasion. 
It is worthy of note in this connection that in the medicinal 
treatment considerable difference is found in the promptness 
with which certain of these affections yield to iodide of potas¬ 
sium.* 
As yet we have practically no data pertaining to the rela¬ 
tion existing between the bacteria and the medicine, especially 
in cases where alteratives have been employed. In the one 
very marked case of the indurated tissue mentioned, and where 
a staphylococcus was the only organism found, Dr. Williams re¬ 
ports very prompt yielding to the iodine treatment. In our fu¬ 
ture examinations, this very practical side of our subject will be 
carefully considered, and it is hoped that sufficient information 
will be obtained concerning the relation of the bacterial con¬ 
tents of the lesions to the action of drugs, that when once the 
first is determined the treatment will be clearly indicated. 
A few other cases of infection in horses and colts have come 
to my notice which furnish still stronger evidence of the marked 
parasitic powers of streptococci over other pyogenic or septic 
bacteria for this species of animals. I will mention three cases. 
/. Peritonitis following Castration .—This was in a horse 
castrated by Dr. Williams. The operation was performed in 
the field and apparently with perfect success. However, a few 
days later, the animal died from acute peritonitis. At the post¬ 
mortem a blood clot was found in the scrotum and the cord 
was thickened. In the abdominal cavity there was a considera¬ 
ble quantity of clear, amber colored serum. The peritoneum 
was hypersemic. 
A number of tubes of different culture media were inocu¬ 
lated from the thickened cord, peritoneal exudate, liver, and 
spleen. All of the tubes inoculated from the liver and spleen 
remained clear. Those inoculated from the serous fluid and 
from the thickened cord developed into pure cultures of strepto- 
* vSee Dr. Williams’ paper on the use of iodide of potassium in the treatment of fis¬ 
tulous withers. 
