HISTORIC DEVELOPMENT OF IMMUNOLOGY 45 



Specificity The word specific designates a 

 characteristic of the phenomena of immunity 

 that is of fundamental importance. It has been 

 found that a given antibody has a very special 

 affinity for the antigen calling it forth, so that 

 its action is obtained in the most pronounced 

 degree with that antigen. This, in the most 

 general sense, is what "specific" indicates in 

 immunology; and practically all antigen-anti- 

 body reactions both those that occur in the 

 body and those that are observable in the test 

 tube follow this law of specific action. 



