1. A procedure for isolating nuclei of the wheat germ in non-aqueous media has been described.
2. Such nuclei were shown to constitute about 50 per cent of the protoplasmic mass and to have a ribonucleic acid content of an order equivalent to that of the cytoplasm.
3. Studies of the distribution of the enzymes—aldolase, phosphoglyceraldehyde dehydrogenase, enolase, and pyruvate kinase—have revealed that the nuclei are the most vigorous sites of glycolytic activity.
4. Analysis of the DPN content of the nuclei in calf tissues—liver, pancreas, and heart—pointed to the probability that glycolytic activity is a characteristic common to many nuclei.
5. The significance of glycolytic activity to nuclear function has been discussed and some suggestive comparisons made between the two energy-yielding systems of glycolytic and oxidative phosphorylation.