1. Methylene blue has no catalytic effect on the oxygen consumption of those normal adult tissues which do not possess aerobic glycolysis. The dye increases the oxygen consumption of these tissues when their respiration has been inhibited by the addition of KCN and their fermentative power thus brought into action.
2. Methylene blue increases the oxygen consumption of normal tissues having aerobic glycolysis, and of tumors.
3. The effect of methylene blue is roughly proportional to the fermentative power of tissues.