Abstract
The course of respiration in control leaves of tobacco (Nicotiana tabacum L.) that were illuminated 4 to 5 hours and then darkened 0.25 to 10 hours and in tobacco leaves starved of carbohydrate by 14 hours or more of darkness was measured as CO2 efflux in light and darkness into CO2-free atmospheres containing 0.04, 2.23, 21, 40, and 100% O2.