Immunity Against Hemorrhagic Septicemia 13- 
Table 15. 
Lengths of surviving periods of animals which were serum-virus 
treated and which died as a result of a second virus infec- 
tion. 
Approximate averages of surviving periods by doses 
and hours 
Serum No. 
15 
c.c. 
10 
c.c. 
5 c.c. 
All doses 
No. of 
rab- 
bits 
Sur- 
viving 
periods 
No. of 
rab- 
bits 
Sur- 
viving 
periods 
No. of 
rab- 
bits 
Sur- 
viving 
periods 
No. of 
rab- 
bits 
Sur- 
viving 
periods 
1052 
3 
32 
3 
56 
2 
48 
8 
45 
1178 
1 
24 
2 
72 
4 
36 
7 
44 + 
1178 
2 
180 
— ■ 
' — 
2 
72 
4 
126 
1434 
3 
56 
1 
48 
' — 
— i 
4 
54 
1828 
1 
24 
1 
24 
— 
— 
2 
24 
Totals 
and averages . . 
10 
67 
7 
55 
8 
48 
25 
57 
Virus control . . 
— 
— 
— 
— 
— 
— 
8 
30 
Tables Xos. 16-23 exhibit the details of the series in which a 
uniform dose of serum was given and the latter followed by the 
virus inoculation of the various groups at times further and 
further removed from the day of serum treatment. 
The results of the experiments set forth in Tables 16-23 are 
summarized in Table 24. They indicate that the animals used 
in the experiment survived only exceptionally when the virus 
dose was given from one to several days after the serum injec- 
tions. 
The influence of the serum in the series is only shown by 
the lengthening of the surviving periods of the treated rabbits. 
This phenomenon is shown in Table 25. In comparison 
with the virus-control rabbits, there is a marked tendency on 
the part of the serum-treated animals to survive longer after 
the virus inoculations. The differences gradually disappear as 
the periods elapsing between the injections of the serum and 
those of the virus become longer. This behavior is shown by 
