38 Nebraska Agricultural Exp. Station , Research Bui . 
SUMMARY OF RESULTS 
1. Of the sera against hemorrhagic septicemia of cattle 
and swine examined, some show marked protective qualities 
which are expressed (a) by preventing death in a considerable 
number of the experimental animals when the latter were inocu- 
lated with virulent cultures and (b) by a lengthening in the 
surviving periods of those which succumbed to the infection. 
In other sera examined, the potency was not sufficient to prevent 
the death of a considerable number of the animals injected and 
the protective qualities of the serum were only shown by a more 
or less manifest lengthening of the surviving periods. 
2. However marked the protective qualities of a given 
serum may be, the passive immunity conferred by it is of a 
rapidly evanescent character and completely vanishes within the 
space of one week. 
3. Animals treated with serum and virulent culture do not 
become actively immune; in other words, the virus injected into 
a passively protected animal in no way renders the immunity 
more lasting. Animals so treated uniformly succumbed to a 
subsequent injection of virus. 
4. The fact that certain sera are in a measure protective 
against infection by Bacillus bipolaris septicus warrants the 
hope that it may be possible so to improve them as to cause 
them to be of practical value. Further study and investigation 
with that object in view are both needed and justifiable. 
(4M) 
