Far and away the
most organized galaxies, and the most numerous (at 72% of the total), are the spirals (such as our own Milky Way, and NGC 4565 in
Figure 1). These typically have a central, elliptical bulge, which has many properties in common with elliptical galaxies (i.e., old stars on semi-random orbits around the center, and without much interstellar plasma). The distinguishing characteristic of spirals is the dominance of their accretion discs.