II. 
MATERNAL TRANSMISSION OF IMMUNITY TO DIPHTHERIA 
TOXIXE AND HYPERSUSCEPTIBILITY TO HORSE SERUM IN 
THE SAME ANIMAL 
We know (loc. cit.. p. 14) that the young* of female guinea pigs 
that have received either before or during pregnancy toxine-antitoxin 
mixtures are hypersusceptible to an injection of horse serum either 
normal or antitoxic. It therefore occurred to me that it would be 
very interesting to determine whether such young pigs were also 
immune to diphtheria toxine. 
For this purpose it was necessary first to test the immunity against 
the MLD. and if the animal recovered to test its hypersusceptibility to 
horse serum. We know (loc. cit., p. 17) that treatment with toxine 
alone does not render a guinea pig susceptible to a subsequent injec- 
tion of horse serum. 
Guinea pigs born of a susceptible mother and from a litter of which 
the other members were immune to diphtheria toxine were also used 
to test the transmission of hypersusceptibility to horse serum. The 
results are as follows: 
FAMILY NO. 1. 
Mother guinea pig Xo. 4495. 103 days before the birth of young given 0. 19 c. c. toxine 
Xo. 7 — 1 immunity unit B27. Local reaction, paralysis; recovered. 
April 25, 1906. Xos. 4495 A, 4495B, and 4495C born. 
June 22. Xos. 4495A and 4495C given 0.007 c. c. toxine Xo. 7. Xo reaction 
third day. Controls died in 2 days 2 hours and 1 day 12 hours. 
The results of this test showed a distinct immunity to diphtheria 
toxine. 
June 26. Both of the above and 4495B, which had received no toxine, were given 
2 c. c. normal horse serum. All three died in less than 45 minutes. 
FAMILY NO. 2. 
Mother guinea pig Xo. 4. (For treatment of mother see p. 14.) 
June 22, 1906. Guinea pigs Xos. 4E. 4F, received 8J times the MLD (see p. 14). 
Both showed slight induration on the third day; recovered. 
June 26. Guinea pigs Xos. 4E, 4F, and 4G were given 2 c. c. normal horse serum. 
All three died in less than 45 minutes. 
(18) 
