Optical activities of oils freshly expressed from viable seeds of rape, soybean and peanut show no change in rotation with time; neither do oils extracted from these materials by diethyl ether, as previously reported by other workers. Similarly, no evidence for racemization of butterfat isolated immediately after milking could be found. On removal of the steroids present, by chromatography on Celite impregnated with digitonin, and removal of the mono-and diglycerides by chromatography on alumina, butterfat maintained the highest degree of optical activity compared to most of the vegetable oils studied. This residual activity of butterfat tends to substantiate preferential location of short chain fatty acids on the 1 or 3 position of the triglycerides.