354 2XFECT10X AXD JMMUMTY. 



toxin solution, but is neutralized by the same anti- 

 toxin. This view is strongly opposed by Arrhe- 

 nius and Madsen, who, working on the basis that 

 the neutralization of toxin takes place according 

 to certain laws of physical chemistry, claim that 

 toxon is nothing more than toxin which has disso- 

 ciated from the toxin-antitoxin molecule. 



8. It is thought that the incubation period 

 which, characterizes the action of toxins represents 

 to a large degree the time required for the action 

 of the toxophorous group after the toxin has been 

 bound by the cells. 



9. Ehrlich stands for the multiplicity of com- 

 plements in opposition to Bordet and others who 

 claim the existence of but one complement 

 (alexin). The various complements differ in the 

 nature of their haptophores, without regard to 

 possible differences in their zymotoxic groups. 



10. Only those organs which have suitable re- 

 ceptors may produce an antibody for a given anti- 

 gen, i. e., only those cells which may enter into 

 chemical combination with the antigen. It does 

 not follow, however, that only those organs which 

 show clinical or anatomic lesions may produce, 

 say, an antitoxin ; for other organs not so suscep- 

 tible to the action of the toxin may still possess 

 the vsuitable receptors and cast them out as anti- 

 toxin. 



causes of The various types of immunity are explainable 

 Typl e of n the basis of the side-chain theory in the follow- 



Immunity. ing terms ! 



1. Natural immunity to toxins may depend on 

 (a) a lack of suitable cell receptors, the toxin con- 

 sequently finding no point of attack; (&) a very 



