ii4 Immunity 



side of the haptophore group another and absolutely independent toxophore 

 group." .... " As has been said, the possession of a toxophile group by the 

 cell is the necessary preliminary and cause of the poisonous action of the toxin." 

 . . . . "If the cells of these organs [organs essential to life] lack side-chains 

 fitted to unite with them, the toxophore group cannot become fixed to the cell, 

 which therefore suffers no injury, i.e., the organism is naturally immune. One of 

 the most important forms of natural immunity is based upon the circumstance 

 that in certain animals the organs essential to life are lacking in those haptophore 

 groups which seize upon definite toxins. If, for example, the ptomaine occurring 

 in sausages, which for man, monkeys, and rabbits is toxic in excessively minute 

 doses, is for the dog harmless in quite large quantities, this is because the binding 

 haptophore groups being wanting, the ptomaine cannot, in the dog, enter into 

 direct relation with organs essential to life." .... "The haptophore group 

 exercises its activity immediately after injection into the organism, while in all 

 toxins with the perhaps solitary exception of snake-venom the toxophore 

 group comes into activity after the lapse of a longer or shorter incubation period 

 which may, e.g., in the case of diphtheria toxin, extend to several weeks." 



"The theory above developed allows of an easy and natural explanation of 

 the origin of antitoxins. In keeping with what has already been said, the first 

 stage in the toxin action must be regarded as the union of the toxin by means of 

 its haptophore group to certain 'side-chains' of the cell protoplasm. This 

 union is, as animal experiments with a great number of toxins show, a firm and 

 enduring one. The side-chain involved, so long as the union lasts, cannot 



<) 



Fig. 20. Cells with various receptors or haptophorous groups of the first 

 order (a), adapted to combination with the haptophorous groups (6) of various 

 chemical compounds brought to them. It will be noted that there is no mechan- 

 ism by which the toxophorous elements of the molecules (c) can be brought to 

 the cell. 



exercise its normal nutritive physiological function the taking up of food-stuffs. 

 It is, as it were, shut out from participating, in the physiological sense, in the 

 life of the cell. We are, therefore, now concerned with a defect which, according 

 to the principles so ably worked out by Professor Carl Weigert, is repaired by 

 regeneration. These principles, in fact, constitute the leading conception of my 

 theory. If after union has taken place new quantities of toxin are administered 

 at suitable intervals and in suitable quantities, the side-chains, which have been 

 reproduced by the regenerative process, are taken up anew into union with the 

 toxin, and so again the process of regeneration gives rise to the formation of 

 fresh side-chains. In the course of the progress of typical systematic immuni- 

 zation, as this is practised in the case of diphtheria and tetanus toxin especially, 

 the cells become, so to say, educated or trained to reproduce the necessary side- 

 chains in ever-increasing quantity. As Weigert has confirmed by many ex- 

 amples, this, however, does not take place by the simple replacement of the defect; 

 the compensation proceeds far beyond the necessary limit; indeed, overcom- 

 pensation is the rule. Thus the lasting and ever-increasing regeneration must 

 finally reach a stage at which such an excess of side-chains is produced that, to 

 use a trivial expression, the side-chains are present in too great a quantity for the 

 cell to carry and are, after the manner of a secretion, handed over as needless 

 ballast to the blood. Regarded in accordance with this conception, the anti- 

 toxins represent nothing more than side-chains reproduced in excess during re- 

 generation' and therefore pushed of from the protoplasm and so coming to exist in 

 the free state." 



