1. Five per cent l-cystine in a stock or low protein diet produces ceroid deposits in rat liver. This effect of l-cystine is much greater in low protein than in stock diets.
2. One per cent choline has an inhibiting effect on deposition of liver ceroid resulting from a low protein diet containing excess cystine.
3. The occurrence of ceroid pigment in the livers of rats on a low protein diet, with or without the addition of excess l-cystine, is transiently inhibited by the administration of α-tocopherol. Five per cent cod liver oil in the diet did not prevent this effect of α-tocopherol.
4. On low protein, vitamin E-deficient diets, there occurs after 4 months, a rapid and progressive weight loss. This does not happen when α-tocopherol is added to the diet.