To the Editor:
—In The Journal (July 18, 1914, p. 246) occurs an editorial on "Butter-Fat in Infant Feeding," which attributes the discovery of the remarkable influence of butter-and egg-fats on growth as contrasted with certain other fats of both animal and vegetable origin, to Osborne and Mendel. Foot-Note 4 states that McCollum and Davis have also pointed out this property for egg-fat, but makes no other reference to our work on this line. The facts in the case are as follows:In the Journal of Biological Chemistry, 1912, xii, 81, Osborne and Mendel discussed the importance of lipoids in the diet during growth, and concluded that their data demonstrated that all lipoids were dispensable from the diet during growth (p. 88). One year later McCollum and Davis (Jour. Biol. Chem., 1913, xv, 167) described for the first time that rats could grow for from eighty to 120 days on