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SummaryThe nutritive quality of crude casein is reduced by continuous extraction with hot 95% ethanol. These results confirm the observations of Hartman and Gary. Rats fed rations containing such extracted casein grow at a reduced rate and develop a characteristic hair loss. The alcohol extracts obtained from the extraction of crude casein do not increase the rate of growth of rats ingesting extracted casein but do prevent the characteristic hair loss. The growth rate of rats ingesting alcohol extracted casein can be increased to normal by feeding fresh liver. The analysis of the extracted casein and the crude casein for 14 amino acids following enzymatic or acid hydrolysis failed to show any appreciable differences.

Summary1. Caloric restriction, causing severe emaciation, followed by ad libitum feeding on the same fat-deficient diet, precipitated symptoms of fat-deficiency in mature rats. When the rats, after depletion, were maintained on the fat-free diet ad libitum for sufficiently long periods, spontaneous recovery was observed.2. The tissues of these rats were analyzed for linoleic, linolenic and arachidonic acids by the spectrophotometrie method. The concentrations of linoleic and arachidonic acids in the body fat were found to vary with the appearance of the symptoms; it was high at the end of the depletion period, and low at the stage when fat deficiency symptoms were present. The higher levels of linoleic and linolenic acids at the time of recovery, after a long period on the fat-free diet, are considered as further evidence for the synthesis of essential fatty acids in the mature rat.3. Supplementation of ethyl linoleate increased the level of arachidonate in the body fat.

SummaryA normal rate of growth for guinea pigs, comparable with the growth on commercial rations, was obtained when potassium acetate and magnesium oxide were added to a purified basal ration containing all of the known nutrients (except vitamin B12) and 15% gum arable. The best results were obtained with 2.5% potassium acetate and 0.5% magnesium oxide.

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Carter and O’Brien (1939) and Hegsted, Oleson, Elvehjem, and Hart (1940) demonstrated the essential nature of vitamin B6 for growing chicks. In a more recent paper Briggs, Mills, Hegsted, Elvehjem, and Hart (1942) showed that the young chick requires from 275 to 300 micrograms of vitamin B6 for optimum growth. We wish to report here studies on the essential nature of vitamin B6 for egg production, hatchability, and maintenance of body weight in mature fowl. In preliminary trials the following synthetic basal ration was found to be satisfactory: dextrin, 58; purified casein, 18; gelatin, 5; soybean oil, 5; salts IV, 5; fish oil, 2 (400 A.O.A.C. units vitamin D, 3,000 I.U. vitamin A); kidney residue, 3; solubilized liver extract, 4. Each kilogram of ration also contained thiamin, 2 3 mg.; riboflavin, 5 mg.; calcium pantothenate, 15 mg.; nicotinic acid, 100 mg.; and choline, 2 gm. Oyster shell was supplied ad libitum.

Eastwood1 showed inositol to be one of the bios factors required by certain yeasts. Recently Woolley2, 3 has demonstrated that the mouse requires inositol for normal growth and the prevention of alopecia. Pavcek and Baum4 have also found inositol to be effective in preventing lack of growth and “spectacled eye” in rats maintained on certain purified diets. These results together with the isolation of phytic acid from chicken blood by Rapoport5 suggested that the chick might also require inositol.Growth responses varying from 18 to 52 g in 4 weeks have been obtained upon the addition of inositol† to several different simplified chick rations (Table I). It is clear that inositol has a definite growth-promoting action although the response varies with the amount of inositol in the ration and the adequacy of the supplement used to supply unidentified growth factors.Ration 477 is the same as ration 470 described previously6 with the following additions: 3% of extracted kidney residue, .15% choline, 15 mg of pa...

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WHILE studying nutritional anemia in 1929, workers in this laboratory found that chicks did not survive when fed milk alone. When whole milk powder, fortified with iron and copper, was fed with the liquid whole milk, the chicks grew poorly (Elvehjem and Hart, 1929). Intermittently, since then, experiments have been set up to try to obtain normal growth of chicks on a milk diet. Two recent experiments are reported here. EXPERIMENT 1 Day-old White Leghorn chicks were put in electrically heated cages with raised screen bottoms. The chicks had a constant supply of whole milk powder and fresh homogenized milk, but no water. The by supplementing each 100 grams with 5 grams of grit, 40 mg. of Fe4(P2 O7)3 · 9H2 O, 2 mg. of CuSO4 · 5H2 O, 0.2 mg. of KI and 30 mg. of MnSO4 · H2 O. In the second experiment vitamins A, D, and E were fed by dropper . . .

To the Editor. —I was much interested in the editorial inThe Journal, June 4, on "Nutrition and Milk Production," and particularly the losses of calcium and phosphorus during the height of milk production. In an extended study of this subject with cows it has been fairly well shown that the losses of calcium in the height of milk production is a process that cannot be stopped by high injections of vitamin D. It appears to be a normal physiologic process, no doubt induced purposely by an overactive parathyroid gland, which is known to influence the abstraction of calcium from the skeleton and for the purpose of maintaining the calcium levels of the blood normal during the unusual draft of calcium and phosphorus in mammary secretion. When the parathyroid fails to function at the initiation of lactation, "milk fever" in cattle results. This can be corrected by the injection of

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