  We have constructed the mass function of globular star clusters in the
Sombrero galaxy in bins of different internal half-mass density rho_h and
projected galactocentric distance R. This is based on the published
measurements of the magnitudes and effective radii of the clusters by Spitler
et al. (2006) in BVR images taken with the ACS on HST. We find that the peak of
the mass function M_p increases with rho_h by a factor of about 4 but remains
nearly constant with R. Our results are almost identical to those presented
recently by McLaughlin & Fall (2007) for globular clusters in the Milky Way.
The mass functions in both galaxies agree with a simple, approximate model in
which the clusters form with a Schechter initial mass function and evolve
subsequently by stellar escape driven by internal two-body relaxation. These
findings therefore undermine recent claims that the present peak of the mass
function of globular clusters must have been built into the initial conditions.
