1. By adding TNT to frog's blood in vitro, certain Heinz bodies would be seen within the erythrocytes, though very few. 2. In case a cock has been reduced to a chronic TNT poisoning, the number of erythrocytes as well as the value of hemoglobin in % would prove a decrease as the degree of poisoning progresses; Heinz bodies appear though slightly within but in the periphery of the erythrocytes.