The experiments here recorded form a continuation of work previously carried out by the author in conjunction with D. P. Rockwood and with W. H. Parker. In the earlier papers it was shown that the bile possesses solvent properties for both free fatty acids and soaps, which taken in conjunction with the hydrolytic action of the pancreatic juice upon fats renders the view highly probable that all the fats of the food are absorbed, not as an emulsion but in soluble form as fatty acids and soaps. Such a view yields an easy explanation of the conjoint action of the bile and pancreatic juice in fat absorption, and of the defective uptake of fat when either fluid is absent from the intestine.