36 Nebraska Agricultural Exp. Station, Research Bui . 21 
Table 47. 
Differences , m hours , between surviving periods of serum-treated 
rabbits and of corresponding virus-control rabbits at vary- 
ing periods after serum treatment. 
Table 48 shows the results of subsequent virus inocula- 
tions at varying periods after serum and first virus injections. 
It is shown that in all animals but one the second virus injec- 
tions killed promptly and that the surviving periods were not 
materially different from those usually encountered in the virus 
controls. 
