In Canada and the USA (population,ca. 270 million), the annual incidence of snake-bites, particularly in the USA, is similar to that observed in Europe. According to Parrish (65) and Russell (81), approximately 45000 snake-bites occur each year in North America. Of these bites about 10000 are inflicted by venomous species, 6500 require medical intervention, and approximately 15 individuals thus bitten die each year . The case fatality rate is very low in view of the high toxicity of the venom of some of the species of snakes (e.g. Crotalus sp.). The implementation of adequate treatment is probably the reason for this low case fatality rate. The deaths that do occur are mainly due to delayed or insufficient treatmen t or to people refusing therapy.