The intravenous injection into rabbits of oxyquinoline sulphate solution (5%) in amounts of 0.8 to 1.5 cc. per kilo leads to bilateral exophthalmos within 1 to 3 minutes, and the degree of exophthalmos depends, as a rule, upon the amount of solution injected. This rapidly induced exophthalmos appears easily and repeatedly in the Dutch and Belgian species whereas many members of the albino species do not respond. The suitable rabbits, however, do not fail to show exophthalmos over and over again upon adequate doses of oxyquinoline.Within 50 to 80 seconds after the introduction of oxyquinoline the ear veins engorge and are very cyanotic, marked hyperpnea appears, the heart rate is rapid, salivation is marked, and from 1 to 3 minutes later, 2 or more limbs become flaccid. From larger doses, 1.5 to 2 cc. per kilo, the animal may die promptly, or—and this is the rule,—it remains almost motionless, all limbs extended and flaccid, the head turned to one side; occasionally convulsions are seen (2 cases) and occas...