ANTITOXIN'S AND RELATED ANTIBODIES 131 



Bacillus diphtheria, the cause of diphtheria. 



Bacillus tetani, the cause of tetanus or lockjaw. 



Bacillus botulinus, the cause of certain cases of botulism or 

 meat-poisoning. 



Bacillus enteritidis, found in certain cases of meat-poisoning. 



The organisms in which true toxins have been demonstrated, 

 but in which the toxin production does not seem to account for 

 the lesions of the disease, are 



Bacillus pyocyaneus, associated with suppurative processes. 



Micrococcus aureus, associated with suppurative processes. 



Micrococcus albus, associated with suppurative processes. 



It should again be emphasized that the above list of bacteria 

 does not include all those which may produce poisoning, but 

 does include the most important known to produce true toxins. 

 Many other species are known to produce endotoxins. 



Specificity of Toxins. Toxins must combine with the cells 

 or tissues of the body in order to injure them. Toxins do not all 

 attack the same tissue, but show a selective action. In some cases 

 a number of tissues may be injured, in others the damage is 

 limited quite strictly to one type. The toxin produced by the 

 bacillus of tetanus attacks the cells of the central nervous system 

 and is called a neurotoxin. One of the toxins commonly present 

 in snake venom destroys red blood-cells (hemotoxiri) . Probably 

 some animals owe their immunity to certain toxins to the fact 

 that some of the less important or non-vital body-tissues will 

 combine with the toxin and prevent its union with more vital 

 portions. 



Antitoxins. Antitoxins are antibodies produced by the tissues 

 of the body as a result of injection or presence of toxins. The 

 fact of antitoxin production may be readily demonstrated by mix- 

 ing the serum of an immune animal with toxin and injecting the 

 mixture into a suitable animal. The normal toxic action will 

 be found to be inhibited by the antitoxin of the serum. The 

 most generally accepted and valuable of the explanations of the 

 production of antitoxins by the body is that offered by Ehrlich, 

 based upon his theory of cell nutrition, the lateral chain or side- 

 chain theory of immunity. 



Ehrlich's Theory of Cell Nutrition. Several explanations have 



