13 
No mother that had received an injection of toxine alone transmitted 
this immunity. 
It will he noticed in both tables that where an immunity is trans- 
mitted to the young all of the litter are immune to about the same 
degree. 
The question will naturally be asked, Why is this immunity not trans- 
mitted by all of the mothers treated with the toxine-antitoxin mix- 
ture ? I can not answer this question positively, hut suggest that it 
may be due to the fact that some of the pigs produce more antitoxin 
than others. It is a well-known fact among producers of diphtheria 
antitoxin that some horses can never be made to produce a serum of 
even 250 units, which is considered a rather low potency serum. 
Such may be the case with guinea pigs. 
The following data, kindly furnished me by Dr. J. J. Kinyoun, 
director of the biologic laboratories of H. K. Mulford & Co., is of 
interest in this connection. It will be seen by reference to the table 
(No. 3) that some horses, in spite of prolonged treatment, never pro- 
duce any antitoxin. 
Table Xo. 3. — Table showing that some horses, in spite of prolonged treatment, fail to 
produce any antitoxin, or only small amounts. 
No. 
Duration of treatment. 
Number 
MLD for 250 
gm. G. P. 
Num- 
ber of 
trials. 
Highest 
value. 
Result. 
1 
14 weeks 
1, 280, 000 
4 
Units. 
0 
Died. 
2 
18 weeks 
1,110,000 
5 
50 
Do. 
3 
19 weeks 
1, 010, 000 
4 
100 
Do. 
4 
20 weeks 
2, 080, 000 
5 
100 
Do. 
5 
do 
1, 800, 000 
3 
100 
Do. 
6 
22 weeks 
1, 520, 000 
5 
0 
Returned. 
7' 
do 
2.390,000 
10 
100 
Do. 
8 
24 weeks 
1, 980, 000 
6 
0 
Died. 
9 
25 weeks 
2, 810, 000 
12 
100 
Do. 
10 
do ; 
2, 590. 000 
0 
0 
Transferred. 
11 
do 
3, 990, 000 
8 
0 
Do. 
12 
26 weeks 
5, 710, 000 
12 
100 
Died. 
13 
28 weeks 
3, 520, 000 
10 
100 
Returned. 
14 
30 weeks 
3, 770. 000 
6 
100 
Died. 
15 
32 weeks 
4, 600, 000 
12 
0 
Transferred. 
16 
36 weeks 
5, 530, 000 
11 
50 
Died. 
17 
do 
4, 000, 000 
15 
100 
Do. 
18 
37 weeks 
4, 500, 000 
14 
100 
Returned. 
19 
39 weeks 
6, 030, 000 
9 
100 
Died. 
20 
47 weeks 
19, 500, 000 
23 
150 
Transferred. 
21 
48 weeks 
10, 560, 000 
20 
150 
Do. 
22 
do 
9. 090. 000 
17 
100 
i 
Returned. 
Attention is called especially to horses Nos. 1, 6, 8, 10, 11, and 15, 
which never produced serum with antitoxic properties. 
