THE VENOMS. 9 1 



It has been known for a long time that the 

 hedgehog and the mongoos eat certain venomous 

 reptiles, and eagerly hunt for the vipers in par- 

 ticular. When the hedgehog is bitten, which 

 happens quite often despite its dexterity, it resists 

 the viper-venom quite well. Physalix and Ber- 

 trand * have experimentally demonstrated that the 

 hedgehog withstands a dose of viper- venom capable 

 of killing at least 40 guinea-pigs. Levin f has 

 shown that young individuals are less resistant, 

 and it is concluded from this, and perhaps incor- 

 rectly so, that the immunity of the hedgehog is 

 naturally acquired, rather than inherent. Bertrand 

 and Physalix have nevertheless shown that on 

 heating the blood of the hedgehog to 88 C. it 

 manifests an antitoxic power toward serpent-venom 

 in vitro. 



Artificial Immunity toward Serpent-venom. 

 Immunity may be conferred upon every individual 

 by utilizing the method of habituation. This 

 fact was simultaneously elicited by Calmette, 

 Bertrand, and Physalix. To effect the immunity 

 these scientists prepare an antivenomous serum 

 and inject it into animals, giving at first very small 

 quantities of the diluted venom, and gradually 

 increasing the doses, and the periods intervening 



* Bull. Museum Histoire Naturelle, i, p. 294; Compt. rend. 

 Soc. de Biol., 1899, p. 77. 



t Deutsche med. Woch., 1898, p. 629. 



