170 PRINCIPLES OF VETERINARY SURGERY 



body as having two combining groups, — one which unites 

 with the bacteria, the "cytophilic haptophore," and one 

 which unites with the complement or "complementophilic 

 haptophore." He therefore calls the immune body, the 

 amboceptor. It attaches itself to the bacteria and renders 

 them vulnerable to the complement, which alone could not 

 dissolve them. The complement evidently has a combining 

 group by which it can unite with the amboceptor, and a lytic 

 group by which it destroys the bacterial cell if united to it. 

 It is, therefore, in structure, similar to the toxin molecule. 

 The action of the immune body and complement upon the 

 bacteria may be graphically represented as follows : 



As we have already stated, the lysins not only dis- 

 solve bacteria, but they also dissolve other cells. If we in- 

 ject the red blood-corpuscles of a horse into a rabbit, the 

 rabbit's blood will dissolve the red blood-corpuscles of the 

 horse. This takes place in a test-tube as well as in the boay. 

 The serum of one animal will dissolve and destroy the red 

 blood cells of another animal of different species. The prac- 

 tical application of this experiment is that it prevents us 

 from inoculating the blood of one animal into another for 

 therapeutic purposes. For example, we cannot replace the 

 blood of a calf which has lost a great deal of blood with that 

 of a horse. However, we could inject him with blood from 

 a cow or another calf with benefit. 



Ehrlich's theory also explains another kind of cell re- 

 ceptor, which governs the phenomena of agglutination and 

 the action of precipitins. The Widal Test for hog cholera 

 depends upon the action of the agglutinins. The efifect of 

 the cholera poisoning, after a few days, is an increase in a 

 number of receptors on the cells of the body. These re- 

 ceptors are stimulated into existence by the cholera toxin, 

 and in consequence they fit nothing except the cholera 

 bacilli. As the cell becomes overloaded with these recep- 



