226 VENOMS 



A number of experiments have been made by Lewin,^ and by 

 Phisalix and Bertrand,- upon the immunity of the hedgehog to the 

 venom of Vipera herns. 



It had long been known that hedgehogs are inveterate hunters 

 of vipers, which they devour with avidity. Thanks to the long and 

 sharp spines by which their bodies are protected, they avoid being 

 bitten and contrive to catch the reptiles vei'y cleverly, but it 

 occasionally happens that they do not escape being struck. How- 

 ever, even in these cases they rarely succumb. 



Inoculation with fairly large quantities of venom does not make 

 them ill : the dose of ciper-yenom lethal for these small animals 

 is about forty times greater than that which kills the guinea-pig. 

 Their power of resistance is therefore beyond doubt. 



It may be asked whether this is due to their blood normally 

 containing antitoxic substances. In order to elucidate this question, 

 Phisalix and Bertrand first proved that the blood of normal 

 hedgehogs is toxic to laboratory animals, especially to the guinea- 

 pig. A mixture of this blood with viper-venom cannot therefore 

 be harmless. But it sufficed to heat hedgehog blood to 58° C. to 

 cause it to lose its toxicity, and it was found that it then became 

 antitoxic. Guinea-pigs inoculated in the peritoneum with 8 c.c. 

 of heated hedgehog-serum were able to withstand, immediately 

 afterwards, twice the lethal dose of viper-venom. 



It really seems, therefore, that the resistance of the hedgehog 

 to venom is due to the presence of antitoxic substances in its 

 blood. But, as in the case of the mongoose, there is no question 

 here of genuine immunity . 



The same is probably true with respect to the herons of 

 Colombia, the Culehrero and Guacaho, which eagerly search after 



' Deatsclie iiiedicinisclie WocJteiiscJirift, 1898. 



- Comptes rendns de la Societe de Biologic, 1895, p. 639, and 1899, p. 77 ; 

 Bulletin du Museum d'Histoirc naturelle, 1895, t. i., p. 294, t. ii., p. 100. 



