220 
TODD AND WOLBACH. 
of the serous surfaces or into the tissues of any of the 
organs; subcutaneous, intramuscular or interfascial hemor- 
rhages also occur; hemorrhages into the subcutaneous, 
edematous areas are frequently seen. The hemorrhages are 
most marked in the advanced cases. Polyuria is a marked 
symptom, and, at the autopies, parenchymatous nephritis 
may be found to be present. Cardiac hypertrophy is well 
marked and thrombosis of the abdominal vessels is occa- 
sionally seen. 
One group of lesions very definitely separates the disease 
studied in Minnesota from that observed in Canada; distinct 
evidence of inflammation accompanied by pus, or fibrous 
adhesions, were frequently found in the peritoneum, the 
pleurae, the pericardium, and in the joints ; abscesses were 
frequently found amongst the muscles. Such appearances 
never occur in the Canadian disease. From these lesions, 
as well as from other body fluids, two bacteria — Bacillus 
equisepticus and Bacillus pyrogenes equinus — were isolated 
with great constancy. Sub-inoculations of cultures of 
Bacillus equisepticus produced symptoms more severe than 
those observed in nature, but similar to them ; the experi- 
mental disease caused death more quickly than did the 
natural disease. 
VII. Diagnosis. — It would be surprising if other dis- 
eases were not confused with one in which the symptoms 
are so indefinite, and in which the course of the infection 
may vary so widely; indeed, where Swamp Fever is com- 
mon, the tendency is to class under that heading all chronic 
febrile conditions of an uncertain nature. 
Mack^^ meets the difficulty by describing four diff'erent 
types: the fulminant, in which horses die after a few hours' 
illness ; the acute, in which the attack lasts for from five to 
seven days ; the sub-acute, in which death comes after a few 
weeks or several months ; and the chronic type, in which 
the animal may live for some years. 
On the other hand, Canadian authors are inclined to 
limit the name Swamp Fever " to the more chronic type 
