The results of these investigations recalled the fact that as early as 1909 Stepp (12) had described experiments in which he had found that bread prepared with milk was capable of maintaining adult white mice without loss of weight for an indefinite period. When the same bread was extracted with alcohol-ether, the animals restricted to it rapidly declined. Replacement of the extracted material failed to restore the dietary properties of the original bread. In later experiments Stepp showed that the addition of the salts which were extracted with the lipoids did not prevent the rapid decline of the animals. Butter additions did not prevent decline, but the addition to the extracted bread, of lipin extracts of egg yolk, bran, dry milk or wheat, restored the extracted bread to dietary completeness.