The available data on masses of ellipticals and lenticulars are summarized with emphasis on the uncertainties in the ratio R of mass to 10-O.6M, where M is the absolute magnitude. With correction for galactic absorption the result is R= 0. ;2147 'o (and, as a by-product, a mean mass-luminosity ratio of 38-+ based on the magnitude scale in the de Vaucouleurs' catalog. The mass-luminosity relations by Poveda, Hood, and Vorontsov-Velyaminov give values of R in the same range. Implications for the mean cosmic density are discussed. Key words: mass-luminosity relation for galaxies - cosmic density