THEORIES OF IMMUNITY. 



moreover, seems to be even less connected with 

 any action of a " specific " nature than the 

 bactericidal property spoken of just now. In 

 this connection it may be of interest to repeat 

 some conclusions reached in an investigation 

 upon this matter some time ago: 1, That the 

 agglutinating property does not lie in and is 

 in no way connected with the flagella of the bac- 

 teria concerned. 2, That agglutination is not 

 to be accepted as a specific property connected 

 with a condition of immunity, although this is a 

 difficult idea to give up. 3, That the homolo- 

 gous nature of agglutination cannot be con- 

 sidered a positive characteristic, for how then 

 explain the clumping of typhoid bacilli by diph- 

 theria antitoxine? 4, Finally that no universally 

 applicable theory of agglutination has yet been 

 offered. That of Bordet (Ann. de lTnst. Past., T. 

 XIII. , p. 224, 1889) seems to us the most rational 

 yet suggested — that there is an agglutinating 

 agent ("agglutinine ") acting upon an agglutina- 

 ble substance (" substance agglutinee," the nature 

 of which is not yet determined), and that this 

 reaction occurs not only with bacteria, but with 

 many other elements — globules, casein, and 



87 



