96 THE TOXINS OF THE HIGHER PLANTS AND ANIMALS 



Crotin is the seed of croton tiglium, a substance less poisonous than 



Crotin. either ricin or abrin. It does not agglutinate, but produces hemolysis 



of rabbits' red blood cells. Toward the red blood cells of other species 



(e.g., bird), it is entirely inactive. The immunization of Babbits is readily brought 



about by subcutaneous injections. Their serum neutralizes the hemotoxic action in 



vitro. 



The Zootoxins. 



Most important of the animal toxins are 



1. Phrynolysin (toad poison). ] _ 



A T_ i . / ., . \ \ Simple hemo toxins. 



2. Arachnolysm (spider poison), J 



3. Snake poison. } _ 



. . Lecithin producing 



4. Scorpion poison, > _ . 



-n hemo toxins. 



5. Bee poison, 



The one striking characteristic of toxins, that an immunity can be 

 raised against them, is also possessed by these poisons. Aside from this fact 

 they present many variations from the true class of toxins. Most of these 

 poisons are complex, i.e., they contain more than one toxin and all are 

 hemotoxic. 



Toad poison is obtained by rubbing up the skins of the Bombinator igneus; spider 

 poison by trituration of the living "cross spiders" (Epeira diadema) in three or four 

 times the amount of physiological salt solution containing toluol. 



The toad and spider poisons contain simple hemotoxins, that is to say, by the mixture 

 of small amounts of this toxin with erythrocytes absolutely serum-free, hemolysis of 

 the latter takes place. Not all species of blood are affected alike. The red blood 

 corpuscles of sheep, goats, and rabbits are especially adapted for experiments with 

 phrynolysin, while rabbits', rats', and human blood is more suitable for arachnolysin. 

 Immunity of rabbits is easily attained. 



Snake Poisons. 



The most familiar poisonous snakes are the Cobras (Naja) of India and 

 Indo-China which belong to the family of Colubridae, the European viper, 

 and the American rattlesnake; the last two being of the Viperidae species. 

 The poisons of these two families show great individual differences. Thus, 

 those of the Colubridae group are decidedly thermo-resistant (temperatures 

 as high as 100 C.) while the viper's poison is entirely destroyed at a tem- 

 perature varying between 80 to 85 C., and markedly weakened at 7oC. 



Snake poisons, as a rule, produce both local reactions at the point of the 

 bite, and severe general disturbances. 



The cobra bite is only slightly painful. A characteristic feeling of stiffness extends 

 from the point of infection over the entire body. In several hours a rapidly increasing 

 weakness sets in terminating in deep coma and death. 



