Abstract The study of gas exchange in tissue slices of corn scutellum incubated either in water or 0·1 M fructose showed that the presence of the hexose increased the rate of glycolysis in this tissue 4- to 7-fold depending on the experimental conditions, and that this increase was quantitatively linked with an aerobic alcoholic fermentation. The properties of crude phosphofructokinase (PFK) were studied and compared with the properties of PFK's from other higher plants, one of which does not carry out aerobic fermentation in the presence of exogenous hexose. Corn scutellum PFK appears to be similar in its properties to the PFK's of other higher plants. The tissue levels of certain metabolic intermediates, some of which influence PFK activity (citrate, ATP, inorganic orthophosphate, and fructose-1,6-diphosphate), were determined and were found not to vary in amount under regimes of low and high glycolytic activity. No evidence was found to support a regulatory role for PFK on the rate of glycolysis in corn scutellum slices. Alternative mechanisms for the control of glycolysis in scutellum slices are proposed. These controls may involve the reactions leading to the metabolic utilization of stored sucrose and the intracellular distribution of adenine nucleotides and inorganic phosphate.