BACTERIOLOGICAL TOXINS AND ANTITOXINS 115 



fact in connection with the latter toxin is that it is produced out- 

 side of the body and not within it. B. botulismus will grow and 

 produce its poison on almost any form of protein. Sausages are 

 probably the most frequent source of botulism. When the food 

 enters the intestines, the poison which is intimately mixed with 

 it is absorbed and the characteristic disease is produced. As in 

 the case of diphtheria and tetanus a specific antitoxin is formed 

 by the body cells seeking to protect themselves from this par- 

 ticular poison. 



The difference between botulism and ptomain poisoning should 

 be clearly understood ; botulism results from eating food contain- 

 ing a true toxin elaborated by the Bacillus botulismus. Ptomain 

 poisoning, on the other hand, results from the ingestion of food 

 that has been decomposed perhaps by several species of bacteria 

 into simple but poisonous compounds. In the former case the 

 poison is produced by bacteria; in the latter the poison is the 

 disintegrated meat, fish, cheese, or whatever the protein may 

 be. Another important difference between the true toxins and 

 ptomains is that the latter do not stimulate the body cells to 

 the production of antitoxin. 



Phytotoxins. Substances resembling in action the bacterial 

 toxins occur in the seeds of some of the higher plants; among 

 them are ricin from the castor oil bean and abrin from the jequirty 

 bean. These toxins of vegetable origin are, like the bacterial 

 toxins, exceedingly poisonous in small amounts, act only after a 

 period of incubation, are destroyed by heat, and produce specific 

 antitoxin. 



Zootoxins. Closely corresponding poisons are found in the 

 blood and secretions of a number of animals. Snake venom, the 

 poisons of scorpions and spiders, as well as poisonous substances 

 present in eel blood, are well-known examples. They, too, like 

 the true bacterial toxins cause the production of antitoxins when 

 injected into the body of another animal. 



Diphtheria Toxin. Diphtheria bacilli usually find lodgment 

 upon some portion of the upper respiratory tract, either the tonsils, 

 the larynx, or not infrequently on the nasal mucous membrane. 



