Abstract
Auto-antivenin capable of neutralizing the effect of a fatal dose (6 to 10 MLD) of the venom of Heloderma suspectum in mice was found in the globulin fraction of Heloderma serum and in extract of the liver of a pilocarpine-injd. Heloderma. Extracts of venom gland, spleen and kidney, and serum of rabbit and chuckwalla had no such effect. On the basis of the auto-antibody hypothesis it is suggested that the auto-antivenin may be synthesized in the same cells (perhaps in the liver) as the venom; after liberation into the blood stream the venom gland would effect a separation, accumulating the venom, which is later secreted, while the antivenin is left in the blood.