  We analyze a sample of 32 galaxies for which a dynamical estimate of the mass
of the hot stellar component, M_bulge, is available. For each of these
galaxies, we calculate the mass of the central black hole, M_BH, using the
tight empirical correlation between M_BH and the bulge stellar velocity
dispersion. The frequency function N(log M_BH/M_bulge) is reasonably well
described as a Gaussian with <log M_BH/M_bulge> ~ -2.90 and standard deviation
0.45; the implied mean ratio of black hole to bulge mass is a factor 5 smaller
than generally quoted in the literature. We present marginal evidence for a
lower, average black-hole mass fraction in more massive galaxies. The total
mass density in black holes in the local Universe is estimated to be 5 x 10^5
solar masses per cubic megaparsec, consistent with that inferred from high
redshift (z ~ 2) AGNs.
