14CO2was applied to apples and bananas that were stored at various temperatures and the incorporation of14C into oxalacetate was determined. Apples that were susceptible to internal breakdown showed an initial decrease in incorporation as the storage temperature was reduced but incorporation then increased at temperatures below 10°C (Jonathan) or 5°C (Twenty Ounce). Apples that were not susceptible to breakdown (Delicious and Granny Smith) showed no incorporation at any temperature. Green bananas showed a minimum incorporation at 10°C but in ripe bananas, incorporation markedly increased at all temperatures less than 20°C. The respiration rate of the apple varieties at 20°C was found to be higher in fruit that were more susceptible to breakdown whereas at O°C the higher rates of respiration were from fruit less susceptible to the dis