RECEPTORS 57 



It is thought that as the soda is brought in contact with the 

 central nucleus of the benzol ring, so foodstuffs unite with the 

 central body of the cell molecule in the organism and nourish it. 



In the case of toxin, the two lateral chains of its molecule are 

 called haptophores and toxophores. The haptophores seize the 

 lateral chains of the cell and the toxophores poison it. 



Ehrlich conceived that cells were nourished by their lateral 

 chains, each having a central nucleus with many lateral chains 

 called receptors bristling all over it. Complex albumins, food- 

 stuffs or poisons (as the case may be) unite with it. This means 

 a chemical union of a part of a cell with all or part of a group of 

 atoms. But certain body cells are only capable of uniting with 

 certain toxins. It is known that the toxin of tetanus has a chem- 

 ical affinity for the nervous system and for its neural elements 

 and not for liver or spleen cells. The poisons of snake venom 

 seem incapable of uniting with any cells of the pig; therefore, this 

 animal is immune to snake venom. 



Now, as these toxins unite with the cells by means of the recep- 

 tors, the cell is stimulated to produce an excessive number of these 

 receptors, which are cast off and become free. Nature is very 

 prodigal and whenever any of the tissues of the body have been 

 injured, or there is a deficiency, an enormous excess of reparative 

 cells is produced. Weigert first called attention to this phenome- 

 non, which has been called Weigert's overproduction theory. So 

 when the haptophores of the toxin molecule combine with the 

 receptors of the cell, the latter are incapable of any further union 

 and are useless to the cell. Accordingly a great number of free 

 receptors are generated, and floating in the blood, engage the 

 haptophorous portion of the toxin. Thus the toxophore is neu- 

 tralized and rendered innocuous before it can reach the cell. 

 These free overproduced receptors constitute the anti-toxin. 

 This is the essence of Ehrlich's theory (Fig. 15). 



Through the process of time and oxygenation the toxophorous 

 group in the toxin becomes innocuous, and only the haptophorous 



