Ripe peas of green color were found richer in vitamin A than those of a yellow color. The former also contained more yellow pigment than the latter.34

Rosenstein and Drummond35 also reported that the A vitamin was to be found contained in the same foodstuffs that contained lipo-chromes, and concluded that it was probably associated in some manner with pigments of the carotin type. Further study, however, showed that the presence of yellow lipochromes was unreliable as an indication of the presence of A and Drummond has abandoned this hypothesis.36

Palmer37 disagrees with Steenbock's assumption and points to the case of cottonseed oil which is golden yellow in color and rich in carotinoids, but is remarkably free from vitamin. The same seems to be true of corn oil. He also adduces the fact that he was able to raise a flock of chickens to maturity on a carotinoid-free diet. These chickens laid carotinoid-free eggs, which hatched into a second generation of chicks, free from carotinoid. He states that either the fat-soluble vitamin and the yellow plant pigments are not related physiologically or the fat-soluble requirement of fowls differs from that of animals.

It may be noted, however, that Palmer's basal ration contained abundance of pork liver, which was believed to be free from carotinoids but fairly rich in A, whereas Rosenheim and Drummond (1. c.) state that liver tissue was found to contain, besides carotin and xanthophyll, a substance which gives certain reactions similar to those given by the lipochromes, but not identical with any known member of that class.

34 Steenbock, Sell and Boutwell, J. Biol. Chem, 47, 303, 1921; J. S. C. I. 1921, 713A.

35 Bosemtein and Drummond, Lancet 1920, 1, 862. See also Drummond, Bioch. J. 13, 81, 1919.

36 Drummond and Coward, Bioch. J. 1920, 14, 668.

37 Palmer, Sci. 50, 501, 1919. Palmer and Kempster, J. Biol. Chem. 39, 299, 1919; Palmer and Kennedy, lb. 46, 559.

From later experiments Palmer and Kennedy38 report that rats will grow and reproduce on ewe milk fat containing only 0.00014 per cent of carotin, or even with carotinoid-free egg yolk as the sole source of vitamin A.

Vitamin B appears to be present to some extent in almost every natural foodstuff. Yeast was considered by Funk to be the most efficient source, but the Lister Institute workers 39 place pressed yeast fourth on the list of substances effective for prevention of beriberi; rice and wheat germ and lentils, being apparently quantitatively superior to it.40 According to Seidell41 fresh pressed yeast is inferior to autolyzed yeast for this purpose.

Bread made from mixtures of wheat flour and soya bean flour was found by Johns and Finks41a to have higher nutritive qualities than that made from wheat flour alone. Feeding tests on rats were made with 15 to 25 per cent soya bean flour in the wheat flour and these trials showed that proteins and vitamin B in amounts sufficient for normal growth were furnished by the ration. In fact the mixed proteins proved two or three times as effective for growth as wheat proteins alone.

Seeds in general contain an abundance of B. As small an amount as 15 per cent of whole wheat as a source of B is sufficient for complete growth in the rat, and so promotes well being as to induce production of nearly the normal number of young, but this amount is not great enough to enable the young to reach weaning age without pronounced nervous disturbances ending in death.42 Beans do not differ greatly from the cereal grains, and dried peas are also markedly efficient.

Dried seeds have varying, generally small, quantities of vitamin A, which are not increased on germination. Green leaves form large quantities from inorganic salts, but the vitamin is not synthesized in the absence of chlorophyll. The vitamin is synthesized by green algae and, to a lesser extent, by red algae, but not by mushroom*.

38 Palmer and Kennedy, L c. 39Funk, Bioch. Bull. 5, 1, 1916. 40 Med. Res. Com. Report No. 88. 41Seidell, J. Biol. Chem. 29, 145, 1917. 41aJohns and Finks, Am. J. Physiol. 55, 465, 1921. 42 McCollmn, Simmondi and Pitz, J. Biol. Chem. 28, 211, 1916-17; See also Osborne and Mendel, Ibid. 87, 590,1919.

Vitamin A of green leaves is not associated with proteins; it may be extracted in the fat removed by solvents and appears in that fraction of the fat which resists saponification.43

With regard to the distribution of the vitamin within the seed, Chick and Hume state that in cereals the anti-beriberi vitamin is mainly deposited in the germ or embryo of the grain and to a less extent in the bran. White wheaten flour and polished rice, which consist of the endosperm of the grain, are deficient in this vitamin. Wheat endosperm, after removal of the aleurone layer in the ordinary milling process, constitutes white flour, which is deficient in antineuritic vitamin and will produce polyneuritis in pigeons or beriberi in man, if used as an exclusive diet, acting in a manner identical with the behavior of polished rice. In both the rice and wheat grain, this vitamin is contained in the germ or embryo, being present to a lesser degree in the bran (pericarp and aleurone layer), probably in the aleurone layer. The embryo of corn grain possesses marked antineuritic properties; both the scutel-lum and the plantlet contain the antineuritic vitamin.44 Bice germ, according to these investigators, is about twice as efficient as wheat germ, weight for weight, as a preventive of beriberi.