154 



ANAPHYLAXIS IN ITS RELATION TO DISEASE 



first injection. But whereas this interval in the first instance is 

 usually from eight to twelve days we now finrl that symptoms 

 appear after from four to seven days. Reactions of this order 



Days I 8 15 i 22 , ..... t 29 



FIG. 2 



15 



Horse 



Serum 



(Allergen) 



Second Injection of 

 Horse Serum 



'rgin 



zriod of Serum 



Incubation Sickness 



Diagram representing the interaction between horse serum and the corresponding ergin in 

 relation to the development of serum sickness and the occurrence of an immediate reaction. 

 (Taken from v. Pirquet.) 



FIG. 3 



FIG. 4 



Pays,! 



Allergen 

 (Second 

 injection) 



Brief Serum 

 incubation Sickness 

 period 



Diagram representing the interaction be- 

 tween horse serum and the corresponding 

 ergin in relation to the occurrence of a double 

 reaction, t. e., an immediate followed by a 

 hastened reaction. (Taken from v. Pirquet.) 



Immediate Hastened 

 Reaction Reaction 



Diagram representing the inteiaction be- 

 tween horse serum and the corresponding 

 ergin in relation to the occurrence of a 

 hastened reaction. Note the greater depth 

 of the antibody fraction as compared with 

 the preceding figure. (Taken from v. Pirquet.) 



v. Pirquet speaks of as hastened reactions. They are readily 

 accounted for if we remember that a cell which has once been 

 stimulated to active antibody formation (sc., liberation) will sub- 



