Light curves in photographic and photographic visual magnitudes have been derived for the variable galaxy X Com from plates taken during the years 1907-74. Three results were obtained from the investigation. A photographic and photoelectric sequence of stars has been established around the galaxy, with positions near the center of the Coma cluster of galaxies. A technique has been developed for removing the effects of seeing from iris photometry of a nonstellar object with respect to a stellar reference system. The light curves show some evidence for both short outbursts and slow, long-term variations in brightness, consistent with the optical activity of a Seyfert galaxy nucleus. Key words: Seyfert galaxy nuclei-photographic photometry