6 
Pagre 
VIII. The action of horse serum upon man and other animals 55 
Man 55 
Other animals 57 
IX. Immunity 59 
Active immunity 59 
Guinea pigs may be immunized against the toxic substance in horse 
serum 59 
Passive immunity 62 
The effect of normal guinea pig blood and organs upon the toxicity 
of horse serum 62 
The neutralizing effect of the blood and organs of an immunized 
guinea pig upon the toxicity of horse serum 64 
X. Feeding experiments 67 
Guinea pigs may be sensitized by feeding horse serum 67 
Guinea pigs may be sensitized by feeding horse meat 69 
May guinea pigs be slightly sensitized by feeding beef ? 70 
XI. Hereditary transmission of the susceptibility in guinea pigs 73 
XII. The toxic action of other albuminous substances 75 
XIII. A review of the literature relating to our work 77 
XIV. Summary and conclusions 91 
