74 
The progeny of the above guinea pig, when about ten days old, was 
tested as follows: 
G. P. Xo. 4463A. One c. e. normal horse serum (roam injected into the peritoneal cavity. 
Symptoms. 
G. P. No. 4463B. . Do. 
FAMILY NO. 5. 
Mother g. p. Xo. 14. Six c. c. normal horse serum (roan) injected into the peritoneal cavity 
Symptoms; recovered. 
[Previous treatment: 94 days prior, inoculated subcutaneously with c - c - antitoxic 
horse serum (Xatl. IX, 18.)] 
The progeny of the above guinea pig, when five days old, was tested 
as follows : 
G.P. Xo. 14A. One c. c. normal horse serum (roan) injected into the peritoneal cavity 
Dead in 30 minutes. 
G. P. 14B. Do. 
G. P. Xo. 14C. Do. Dead in 35 minutes. 
It is plain from the above that yoimg guinea pigs born of a suscep- 
tible mother are themselves susceptible, often more so than the mother 
herself. 
To control the effect of horse serum upon such young guinea pigs 
the following data are given: 
(All controls bom of normal parents.) 
Control g. p. Xo. 01. One c. c. noimal horse serum (roan) inoculated subcutaneously when 
5 days old. Xo symptoms. 
Control g. p. Xo. 02. Two c. c. same serum when 1 week old. Xo symptoms. 
Control g. p. Xo. 03. Same injection when 6 days old. Xo symptoms. 
Control g. p. Xo. 04. Same injection when 4 days old. Xo svmptoms. 
These four controls were selected from four different litters. 
These results upon the hereditary transmission of the susceptibility 
to the poisonous action of horse serum in guinea pigs may throw light 
upon the well-known inherited tendency to tuberculosis in children 
born of a tuberculous parent. 
There are certain analogies between the action of tuberculosis and 
horse serum. Both produce a hypersensitiveness and also a certain 
degree of immunity. Xow that we have proved that this hypersen- 
sitiveness or anaphylactic action in the case of horse serum may be 
transmitted hereditarily in guinea pigs, may it not throw light upon 
the fact that tuberculosis £ ’runs in families?” While there are 
several recorded instances demonstrating that immunity to certain 
infectious diseases may be transmitted from a mother to her young 
this is, as far as we know, the first recorded instance in which hyper- 
sensitiveness, or anaphylaxis, has been experimentally shown to be 
hereditarily transmitted from a mother to her young. 
