Left: relationship between the spectroscopic and evolutionary masses derived in NGC 55 (the one-to-one trend is marked with a black solid line). Right: the logarithm ratio of masses versus their luminosity in this work (black dots), together with the results published previously in other galaxies by Kudritzki et al. (2008), Urbaneja et al. (2008) and U et al. (2009) (open circles). Those objects that show higher evolutionary mass compared with the spectroscopic counterpart are highlighted with gray squares for quick contrast with Fig. 7. The opposite behavior is indicated with gray diamonds.