1. The uptake of lipid by the small intestine of the pig was examined by the perfusion of a segment of the jejunum with radioactively labelled lipid in vivo. The rate at which lipid was presented to the small intestine under specific dietary regimes was also examined by means of re-entrant fistulas in the duodenum and jejunum.

2. The capacity of the small intestine to absorb micellar lipid, prepared in vitro or isolated from intestinal contents, was much in excess of the normal rate of flow of fat into the small intestine.

3. There was little uptake of lipid when emulsions of oleic acid were examined, suggesting that the absorption of particulate fat is probably of little importance in pigs.

4.No specificity in the removal of fatty acids from their mixed micellar solutions was observed.

1. Young rats were given, for 9 weeks, vitamin E-deficient diets containing either 20% or 10% casein, with and without a dietary supplement of 350 ppm D-α-tocopheryl acetate. For the next 5 weeks the casein content of the low-protein diets was decreased to 7%.

2. The low-protein diets induced severe growth depression.

3. The dialuric acid-induced haemolysis test showed that the rats given the 20% casein vitamin E-deficient diet were depleted of vitamin E, but that the rate of depletion on the lowcasein diet was slower.

4. Haemoglobin levels were slightly decreased by the 10% casein diets after 9 weeks, but this difference was not found after 14 weeks, comparing 20% and 7% casein. Dietary vitamin E had no effect on haemoglobin levels or erythrocyte counts.