THE general distribution of vitamin B is now fairly well defined, but the adequacy of different food substances in this respect for different species and the distribution of the various factors in the B complex are still subjects for investigation. R. H. A. Plimmer, with W. H. Raymond, J. Lowndes, and J. L. Rosedale, has examined the comparative vitamin B value of cereals, pulses, and nuts (Bio-chem. Jour., vol. 21, p. 1141, 1927: vol. 23, p. 545; 1929). The preventive method was employed, using pigeons, and the criterion was maintenance for at least 26 weeks. All the vitamins required by the pigeon were therefore included in the estimation; symptoms of deficiency were paralysis and loss of weight. The diets used contained 5 per cent fish meal, white flour or white rice, and the substance under test in varying proportions. Dried yeast contained most vitamin: of the other foodstuffs, wheat germ was about half as good as the yeast, whole wheat, bran, and middlings contained about a tenth of the amount present in yeast, and other cereals about a twentieth. The majority of the pulses and nuts examined contained between a fifth and a tenth of the quantity present in yeast. More vitamin B is required for hatching and rearing young than for maintenance. Chickens require half as much again as pigeons, rats only about half; the requirements of human beings may be intermediate between those of the pigeon and the rat.