SCORPION POISON 157 



and antiveiiin is certainly a chemical one, being likened by Kyes ^^ 

 to that of strong acids upon strong bases. 



The serum of animals immunized to venoms contains precipitins 

 for the proteins of these venoms, and, to some extent, for the serum 

 proteins of the same species of snakes. These precipitins are highly 

 but not absolutely specific, and thc}^ bear no exact quantitative rela- 

 tion to the other antibodies present in the same sera. 



As is well known, snakes are nearly or quite insusceptible to snake 

 venom. Cunningham ^- found that serum of cobras was devoid of 

 antitoxic property, so the immunit3' of snakes must be ascribed to an 

 absence of cell receptors in their tissues, with which their venom am- 

 boceptor can combine. The reputed immunity of the mongoose and 

 hedgehog depends partly on a relatively low susceptibility, but prob- 

 ably more on the agility of the mongoose and the defensive spines of 

 the hedgehog. 



Platypus Venom. — The only mammal with a venomous secretion 

 is that strange freak, the duck-billed platypus (Ornithorhynchus par- 

 adoxus). The males have a hollow movable spur on each hind foot, 

 communicating like a fang with the venom gland, which secretes a 

 venom with properties resembling the venoms of the Australian snakes, 

 but much weaker. 



SCORPION POISON -3 



This poison is secreted by a pair of specialized glands in the pos- 

 terior segment of the elongated abdomen, surrounded by a firm cap- 

 sule with a sharp apex through which the poison is discharged. Its 

 efll'ect on man is usually confined to local pain, swelling, and occa- 

 sionally phlegmonous inflammation with constitutional s^'mptoms 

 after bites from the largest species. In Africa a large scorpion (An- 

 droctonus) exists, that is reputed frequently to cause fatal poisoning, 

 especially in children. The majority of serious results folio-wing 

 scorpion bites, as well as bites of poisonous insects to be considered 

 later, are, however, due to infection of the wound, which occurs read- 

 ily because of local necrosis and hemorrhages, and also because of 

 the unfavorable conditions existing in tropical climates. Apparently 

 these bites favor local infection much as do those of vipers. 



When general symptoms do occur, they are described as resembling 

 strychnine poisoning, with trismus, stiffness of the neck and eventu- 

 ally of the respiratory muscles, which seems to be the chief cause of 

 death (Cavorez). Thompson,'^* however, observed only seldom severe 

 symptoms, consisting of general paralysis that passed off in a few 

 hours. Most experimenters with scorpion poison describe it as chiefly 



r.iBerl. klin. Woch., 1904 (41), 494. 



52Xature, 1896 (5.5), 139. 



53 A complete discussion of the literature on poisonous invertebrates, etc., is 

 given by v. Fiirth, "Vergleichende cliemiselie Phvsiologie der niederen Tiere," 

 Jena. 1903: and bv Faust, "Die tierischen Gifte," Braunsclnveig. 190G. 



54Proc. Acad. Nat. Sci. of Philadelphia, 1S8C, p. 299. 



