The " Lateral-Chain Theory " of Immunity 1 1 1 



water. To take the example of sugar, in the union with 

 protoplasm, not sugar itself as such, but a portion of it, 

 comes into play, the sugar losing in the union some of its 

 characteristic reactions. The sugar behaves here as it 

 does, e. g., in the glucosids, from which it can only be 

 obtained through the agency of actual chemical cleavage. 

 The glucosid shows no traces of sugar when extracted in 

 indifferent solvents. In a quite analogous manner the sugar 

 entering into the composition of albuminous bodies (gly- 

 coproteids) cannot be obtained by any method of extrac- 

 tion ; at least not until chemical composition has previously 

 taken place. It is, therefore, generally easy by means of 

 extraction experiments, to decide whether any given com- 

 bination in which the cells take part is, or is not, a synthetic 

 one. If alkaloids, aromatic amines, antipyretics, or anilin 

 dyes be introduced into the animal body, it is an easy 

 matter, by means of water, alcohol, or acetone, according to 

 the nature of the body, to remove all these substances quickly 

 and easily from the tissues." 



"This is most simply and convincingly demonstrated in 

 the case of the anilin dyes. The nervous system stained with 

 methylene-blue or the granules of the cells stained with 

 neutral red at once yield up the die in the presence of alco- 

 hol. We are, therefore, obliged to conclude that none of 

 the foreign bodies just mentioned enter synthetically into 

 the cell complex; but are merely contained in the cells in 

 their free state." .... "Hence with regard to the 

 pharmacologically active bodies in general, it is not allow- 

 able to assume that they possess definite atom groups, 

 which enter into combination with corresponding groups 

 of the protoplasm. This corresponds, as I may remark 

 beforehand, with the incapacity of all these substances to 

 produce antitoxins in the animal body. We must, therefore, 

 conclude that only certain substances, food-stuffs, par 

 excellence, are endowed with properties admitting of their 

 being, in the previously defined sense, chemically bound by 

 the cells of the organism. We are obliged to adopt the view 

 that the protoplasm is equipped with certain atomic groups, 

 whose function especially consists in fixing to themselves 

 certain food-stuffs of importance to the cell-life." We may 

 assume that the protoplasm consists of a special executive 

 center, in connection with which are nutritive side-chains, 

 which possess a certain degree of independence and which 



