330 LOCAL TLSSUE REACTIVITY 



travenous, intiacardial, iiitraniu,s( ulai and other parenteral 

 methods ol injection of tliese antigens. The hypersensitive state 

 may appear at \arying periods alter the sensitizing injection. The 

 quantity ot antigen injected infhiences the lengtli ol the incuba- 

 tion time. Guinea pigs may be actively sensitized within five to 

 seven days, not reaching their most highly sensitive condition, 

 however, luitil the eighth or fourteenth day after the injection. 

 Zinsser states tliat rabbits are not sensitized to general anaphylaxis 

 as readily as guinea j^igs. A series of preliminary injections is re- 

 quired before fatal shock can be elicited. Rabbits are not highly 

 sensitive imtil a considerable amoinit of antibody has become 

 apparent in tlie blood. This is also true of the Arthus phenomenon 

 in the rabbits. Grove (1932) fomid that the following method 

 was successful for anaphylactic sensitization in these animals: 



Rabbits received approximately 1 c.c. of a 50 per cent solution 

 of egg white intravenously, followed five days later by 5 c.c. of 

 undiluted egg ^vhite intraperitoneally. After a five day interval, 

 5 c.c. of undiluted antigen ^vas injected intraperitoneally, then on 

 seven successive days intraperitoneal injections of 1 c.c. were 

 given. One ^veek later subcutaneous injections of il/4 c.c. of un- 

 diluted egg white in the abdomen ^vas followed seven days later 

 by the final test intravenous injection of 5 c.c. of 50 per cent egg 

 white. Of 53 rabbits treated in this manner, 70 per cent were 

 made sensitive to the intravenous test, 5.6 per cent shelved only 

 slight symptoms, 24.4 per cent sho^ved no symptoms. The same 

 results were obtained Avith horse serum. 



The conspicuous example of true anaphylaxis in rabbits, is 

 ho\ve\er, the Arthus phenomenon. The literature has recently 

 been completely reviewed by Nordmann (1931). The original 

 experiment of Arthus demonstrated that several subcutaneous in- 

 jections of animal serum into rabbits changed the local reaction 

 of the skin to subsequent injection of the same kind of serum 

 (Arthus and Breton, 1903) . The Arthus phenomenon is best 

 elicited by Av^eekly single subcutaneous injections. After the third 

 and fourth subcutaneous injection, the site injected is red and 

 edematous. After the fifth injection the infiltration is firmer and, 

 according to Opie, persists for five to six days. After the sixth 

 injection there is severe injury to the edematous tissue and pus 

 may be formed. After the seventh injection the skin undergoes 

 central necrosis and hemorrhage. 



The hypersensitive state once elicited may persist almost indef- 



