90 ANTIGENS AND ANTIBODIES 



Interesting from theoretical grounds is the fact that many other 

 true toxins have been discovered which are not of bacterial origin. 

 To this category belong certain snake poisons (venin), the phryn- 

 olysin found in the skin glands of toads (Bombinator igneus) and 

 salamanders (Sieboldia), a poison obtained from special glands of 

 certain fishes (Trachinus), the arachnolysin of various spiders (Latro- 

 dectes and Epeira), the poison of wasps and bees, the ichthyotoxin 

 which is found in the serum of the eel, and possibly also the toxin 

 producing fatigue, which, according to Weichardt, is formed in the 

 muscles after severe exercise (kenotoxin). In addition to these, 

 certain toxins produced by higher plants are recognized as possessing 

 true antigenic properties, such as the ricin obtained from the seeds 

 of the castor oil bean (Ricinus communis), the abrin of the jequirity 

 bean (Abrus precatorius), the crotin of croton seeds (Croton tiglium), 

 the robin obtained from the bark of the Robinia pseudoacacia, and 

 the phallin of the poisonous mushroom Amanita phalloides. 



All these substances are characterized by their poisonous nature 

 and the fact that their introduction into the animal organism, in 

 suitable dosage, gives rise to the production of corresponding anti- 

 toxins which in turn have the power of neutralizing the toxic effect 

 of the substances that gave rise to their formation. 



Bacteriolysins. Closely following upon the discovery of the anti- 

 toxins came the work of Pfeiffer and his pupils on the bacteriolysins 

 (1894), viz., antibodies which result upon immunization (vaccination) 

 with various bacteria and which possess the property of causing the 

 dissolution of the corresponding organisms (Pfeiffer's phenomenon). 

 Antibodies of this order are notably produced against certain vibrios, 

 such as the vibrio of Cholera Asiatica, the vibrio Metschnikoffi and 

 related forms, against the typhoid and paratyphoid bacillus, the 

 colon bacillus, the dysentery bacillus, the bacillus pyocyaneus, the 

 influenza bacillus, and the bacillus of bubonic plague. 



When these substances were first discovered it was hoped that the 

 corresponding bacteriolytic sera would be found to possess curative 

 properties analogous to those of the antitoxic sera, but it was soon 

 ascertained that while they can prevent infection when they are 

 introduced together with the organisms or shortly after, they are of 

 little if any apparent avail in combating an already established 

 infection. Why this should be is not clear, unless we assume that 

 the organisms have developed new characteristics, in consequence of 



