The "Lateral-chain Theory" of Immunity iii 



toxin into toxoids which were not poisonous, and was shown to be 

 quite independent of the antitoxin combining aflSnity of the filtrate 

 which remained unaltered. The inevitable interpretation seemed 

 to be the existence in the bouillon of the haptophorous and toxo- 

 phorous groups described. Similar toxophorous and haptophorous 

 groups were shown to exist in other toxins — tetanolysin by Madsen, 

 venoms by Myers, and milk-curdling ferments by Morgenroth. 

 The neutralizing action of the antibodies produced in the blood of 

 animals immunized to these various substances depends upon the 

 immediate and direct combination or union of haptophorous groups 

 in the antibodies with corresponding haptophorous groups of the 

 respective toxins or active bodies. 



The physiological activities of toxins differ from those of alkaloids 

 and other poisons in three fundamentals: first, in their abihty 

 to produce antibodies in the bodies of animals into which they are 

 injected; second, the manifestation of poisonous action only after 

 a definite incubation period, and third an extremely labile com- 

 position, by which the toxin becomes quickly transformed to 

 toxoids. 



lU^o/JtiLe loxo/AUe Habtop/iore Toxophore 

 gnoufi. groufr. ^roufi. g^oufi., 



Fig. i8. — Diagram to represent tlie combining groups of the cell and of the 

 toxin respectively (after Ehrlich) (Hewlett). 



Study of the physiological action of toxins upon the cells resulted 

 in showing that certain definite specific affinities existed, and that 

 the union of the toxin with the cell antedated the production of 

 symptoms. In some cases it was even found possible to disconnect 

 the anchored toxin by bringing to the cells haptophorous groups for 

 which the haptophorous elements of the toxin molecule were known 

 to have an active affinity. Donitz determined the quantity of 

 tetanus antitoxin which, injected into the circulating blood imme- 

 diately after the toxin, absolutely neutralized it and rendered all 

 of the circulating toxin innocuous. If the same quantity of antitoxin 

 was given seven or eight minutes after the injection of the toxin, 

 death occurred from tetanus, exactly as if no antitoxin had been 

 given. Evidently the toxin had anchored itself to the nerve-cells 

 too quickly for the antitoxin to reach and combine with it. Hey- 

 mans found that if an animal was injected with tetanus toxin and 

 its entire blood withdrawn immediately afterward and replaced by 



