SPIDER AND CENTIPEDE POISONS 181 



apparently not poisonous for mammals, except the " cross 

 spider " (Epeira diademd), which has since been thoroughly 

 studied by him and by Sachs. 1 In these spiders also the poison 

 is found throughout the body. It resembles the snake venoms 

 strikingly, according to Sachs, for it contains a powerful hemo- 

 lysin which he calls " arachnolysin," acting very differently 

 with different sorts of blood, and destroyed by heating at 

 70-72 for forty minutes. Only such blood is hemolyzed as 

 is able to bind the poison in the stroma of the red corpuscles. 

 By immunizing a guinea-pig Sachs succeeded in securing an 

 antitoxin of some strength. The discovery of this hemolysin 

 explains Robert's observation of hemoglobin, methemoglobin, 

 etc., in the urine of persons bitten by spiders. 



Von Fiirth considers that the bite of the historically famous 

 Italian tarantula is able to cause no more than local inflamma- 

 tion, and Robert found that the entire extract of six Russian 

 tarantulas (which are supposed to be more poisonous than the 

 Italian) caused no symptoms when injected into a cat. 



In all probability the other poisonous spiders possess toxic 

 substances allied to those of the venoms, with hemolytic, 

 agglutinative, and neurotoxic products, Sachs' studies indicating 

 the general similarity of all the zootoxins. 



CENTIPEDES 



Undoubtedly the severity of centipede poisoning has been 

 greatly exaggerated, the results being usually limited to local 

 inflammation, frequently spreading some distance in an ery- 

 sipelas-like manner. An authentic case of fatal poisoning of 

 a child four years old by a centipede (Scolopendra heros) has 

 been reported from Texas by G. Linceicum, 2 death resulting 

 five to six hours after the bite was received. Besides the local 

 pain and inflammation, vomiting was marked, occurring also in 

 five other non-fatal cases. 



Centipedes secrete their poison in relatively large glands, 

 which discharge at the apices of a pair of specialized claws that 

 take the place of the first pair of legs. The nature of this 

 poison seems not to have been investigated. Numerous chemical 

 substances are described as secreted by other glands of these 

 animals, including prussic acid and a camphor-like matter (see 

 v. Furth). 



1 Hofmeister's Beitr., 1902 (2), 125. 



2 Amer. Jour. Med. Sci., 1866 (52), 575. 



