16 IMMUNE SERA 



It will be seen that in the above experiments 

 the completely non-poisonous toxoid, although it 

 effected an increased production of receptors, did 

 not cause their thrusting-off. The serum of the 

 rabbit treated with toxoid contained no antitoxin 

 whatever. Wassermann concludes from this and 

 other experiments that the thrusting-off cannot be 

 a function of the haptophore group, and that 

 something additional is required. This " some- 

 thing," he claims is a function of the toxophore 

 group. It may be stated that Von Dungern has 

 also published experiments (with majaplasm) point- 

 ing to the existence of the second stage, the stage of 

 sessile receptors. 



Antigens or Haptins. It has been found that 

 it is impossible to produce any immunity against 

 all poisons, e.g. strychnine or morphine. Accord- 

 ing to Ehrlich these simpler chemical molecules do 

 not enter into a true chemical combination with 

 the tissues, but form rather a kind of solid solution, 

 a loose combination with the cells, so that they can 

 again be abstracted from these cells by all kinds of 

 solvents, e.g. by shaking out with ether or chloro- 

 form. The point can perhaps be likened to the 

 difference between saccharin and sugar. Both sub- 

 stances taste sweet, but despite this similarity in 

 their physiological action they behave very dif- 

 ferently toward the cells of the organism. Sac- 

 charin simply passes through the organism without 



