272 



LOCAL TLSSIJE REACTIVITY 



In tliese exj^erinients, the second or sul).sc(|ucnl intravenous 

 test injection oF the animal jjroteiii to which the rabbits were 

 sensiti/ed. resuhed in a severe hemorrhagic and necrotic lesion 



I'iG. 29. Rabbit sensitized Ijy single injection of horse seriuii six days pie\i()usl\. 

 received intradermal injection of 0.25 ex. of inidilnted B. typhosus active principles. 

 Twenty-four hoins later rabbit was injected intravenously with horse serum. Appear- 

 ance of reaction at prepared skin site four hoins after intra\enoiis injection of horse 

 serimi. 



at the site prepared by the bacterial filtrate. The lesions \vhich 

 were intense in the majority of rabbits ^vere characteristic of 

 the phenomenon of local skin reactivity to bacterial filtrates. The 

 reactions appeared very promptly. They became visible one-half 

 hour after the intravenous injection and fully developed one and 

 one-half hoius after the intravenous injection. Unquestionably, 

 the time recjuired for the appearance of the reaction here ^vas 

 shorter than in the experiments when bacterial filtrates Avere used 

 for the provocati\e injections. The interpretation of the experi- 

 ments was that the interaction of the protein injected ^vith the 

 actively acquired antibodies against this protein resulted in for- 



