DURING investigations on the synthesis of sucrose from glucose-1-phosphate and fructose by pea seed extracts it was observed that a glycolytic system was operating in the enzymic digests1,2. The pea extract had been partially purified by precipitation with ammonium sulphate (80 per cent saturation) and dialysis against phosphate buffer at pH. 7.0. It was found that there were differences in glycolytic activity when the enzymic digests were incubated under aerobic and anaerobic conditions.