RESEARCH BULLETIN NO. 21 
THE UNIVERSITY OF NEBRASKA 
BULLETIN 
OP THE 
AGRICULTURAL EXPERIMENT STATION 
OF 
NEBRASKA 
STUDIES OF IMMUNITY AGAINST HEMOR- 
RHAGIC SEPTICEMIA 
By L. Van Es and H. M. Martin 
DEPARTMENT OF ANIMAL PATHOLOGY AND HYGIENE 
August, 1922 
LINCOLN, NEBRASKA 
U. S. A. 
