19 
FAMILY NO. 3. 
Mother guinea pig Xo. 8. (For treatment of mother see p. 16.) 
June 22, 1906. Guinea pig Xo. CG given 8J times the MLD. Showed slight 
induration on the third day; recovered. 
June 26. Guinea pigs Xos. 8G and 81 given 2 c. c. normal horse serum. Both 
died in less than 45 minutes. 
Four control pigs of about the same age and weight, born of 
untreated mothers, received 4 c. c.— twice the amount given the test 
pigs — of normal horse serum. None showed any inconvenience as a 
result of the injection. 
It will be readily seen from the above that a mother can transmit to 
the same young two properties, viz, immunity to diphtheria toxine and 
hypersusceptibility to horse serum. 
It is therefore very manifest that female guinea pigs that have 
received the toxine-antitoxin mixtures should not be used as breeders 
by those engaged in work with diphtheria antitoxin. On account of 
the transmitted immunity misleading results in the testing of antitoxin 
and toxine will be had. On account of the hypersusceptibility to the 
injection of horse serum pigs derived from such a source, when used 
to determine the presence of bacterial or toxic impurities may die, not 
from the presence of such impurities, but on account of a hypersus- 
ceptibility to horse serum transmitted from the mother. 
O 
