Five-day-old seedlings of wheat were placed in an atmosphere of C14O2and permitted to carry on photosynthesis continually for 7 to 8 days. At the end of this time the leaves were extracted with 85% ethanol. The alcohol-insoluble residue was hydrolyzed with 1 Nhydrochloric acid. The hydrolyzate was deionized, concentrated, and streaked on Whatman No. 3 MM paper. The sugars were separated by one-dimensional chromatography in butanol/pyridine/water and found to be present in the following relative amounts: glucose > xylose > arabinose > galactose.