In the article Tissue Reactions to Metals—The Influence of Surface Finish by Jonathan Cohen, M.D. in the July 1961 issue on page 688, the last sentence of the first paragraph under the heading Materials and Methods should read "The thickness of the surface finish, measured with a profilometer with fine stylus, was, for the sand-blasted finish, thirty to fifty-five micro-inches, for the vapor-blasted finish, forty to fifty micro-inches, and for the electropolished finish, twenty to twenty-five micro-inches.