Results of tests with groups of white rats show that 30 per cent of white corn in the Sherman and Spohn vitamin B-free diet does not supply an amount of vitamin G sufficient to promote growth or to prevent the occurrence of symptoms of pellagra. Normal growth results when 30 per cent of white corn is fed as the only source of vitamin B in the Sherman and Spohn diet to which autoclaved yeast has been added to supply vitamin G. An 80 per cent by weight alcohol extract of white corn fed at a level of 3 per cent supplies an amount of vitamin B sufficient for normal growth, and contains very little vitamin G. These tests also indicate that rats on a diet free from, or at least containing only minimal amounts of, vitamin G, tend to maintain weight for some time at or near their initial weight. This gives further evidence that the diet carrying 30 per cent of white corn contains very little vitamin G. On a diet in which the vitamin G carried by 30 per cent of white corn was the limiting factor, growth of young rats is shown to be proportional to the vitamin G of the test food fed in addition to this basal diet. Results of tests with autoclaved yeast and with a vegetable extract are given. In cases where conditions do not permit of the preparation or purchase of vitamin B extracts for use in vitamin G assays, white corn to the amount of 30 per cent of the diet may be used to supply an adequate amount of vitamin B with little addition of vitamin G. When this diet is used all comparisons must be made relative to the growth rate of the controls on the basal diet only.