Detached tobacco leaves were placed on solutions of uniformly C14-labelled glucose, "dextrins", and "oligosaccharides" which had been obtained by amylolysis of C14-starch with ptyalin. All three carbohydrates were absorbed by the leaves, and their subsequent metabolism was found to be essentially the same. This observation eliminates the earlier suggestion that the absence of free maltose during the breakdown of starch in tobacco leaves is due to the fact that its precursors are exceptionally active and are metabolized away before they have a chance to give rise to free maltose.