20 Nebraska Agricultural Exp. Station , Research Bui. 21 
Table 20. 
Differences , in hours , between surviving periods of serum-treated 
rabbits and of corresponding virus-control rabbits at vary- 
ing periods after serum treatment. 
Differences 
1 day 
3-4 days 
7-8 days 
11-12 days 
14-16 days 
95.7 
72.5 
\ 
\ 
10.5 
9.3 
3.9 
N. B. The evidence of one virus-control rabbit lingering 336 hrs. 
and of one serum-treated rabbit lingering 408 hrs. was not included in 
this graph. 
SWINE STRAIN SERA 
Tn this series the same general plan of inquiry as reported 
on the preceding pages was followed. The first part of the tests 
made pertain to sera which were injected in varying doses. In 
one of the tests (No. 1053) a control set of rabbits injected with 
normal serum was used in order to be able to estimate whatever 
influence a normal serum may have. The details* of the 
tests in this series are presented in Tables 27-34. 
serum 
