TOAD TOXINE (PHEYNOLYSINE). 233 



fixed power of reacting upon any poison absorbed. But surely 

 this condition must depend, in the main, upon an innate want 

 of receptors ; for, as we have seen, even the blood of venomous 

 snakes is poisonous. 



In the case of the hedgehog, too, which is to some extent 

 refractory, the want of susceptibility appears to be principally 

 due to its possessing few receptors; after the introduction of 

 the venom its blood also is poisonous. The effect of the venom 

 upon the hedgehog is similar to that of tetanus toxine upon 

 the alligator ; for the hedgehog, although but slightly suscep- 

 tible, yet produces fairly considerable amounts of antitoxine. 

 It thus appears to possess receptors, but these are, for the most 

 part, in the organs less vitally important. On the other hand, 

 CALMETTE (1895) found the serum of the pig and mongoose to 

 contain extremely little antitoxine, although both animals are 

 almost completely immune to snake venom. 



Doubtless this is also the case with snakes themselves. The 

 main cause of their insusceptibility may be a congenital want 

 of receptors, or to the existing receptors being too far apart ; 

 but at the same time it is, of course, not improbable that they 

 also produce antitoxine and excrete it with the bile. 



Toad Toxine (Phrynolysine). 



Certain toads contain in their skin and blood, in addition to the 

 better-known alkaloidal poisons (bufotaline, &c.) an apparently 

 true toxine possessing hsemolytic powers. 



PHISALIX and BERTRAND 1 appear to have been the first to 

 discover the existence of a second poison, and its hsemolytic 

 action was recorded by PuGLiESE. 2 



"Phrynolysine" was then investigated more closely by PRO- 



SCHER. 3 



In his experiments PROSCHER chiefly employed extracts of the 

 skin of the fire toad (Bombinator igneus), though the skin of the 

 garden toad (Eufo cinereus) was also used. 



Phrynolysine has all the characteristics of toxines, and par- 

 ticularly their great sensitiveness to external influences. It is 

 non-dialysable. It becomes inactive fairly rapidly. 



It produces haemolysis equally well in a neutral or slightly 



1 Phisalix and Bertrand, "Recherch. s. la toxicite du sang du crapaud 

 commun," Arch. d. Phys., xxv., 517, 1893. 



2 Pugliese, Arch. d. Farm., 1898, quoted by Proscher (loc. cit.). 



3 Proscher, " Zur Kenntnis des Krotengiftes " Hofm. Beitr., i.. 575. 

 1901. 



