  We determine the mass function of young star clusters in the merging galaxies
the ``Antennae'' (NGC 4038/39) from deep images taken with the WFPC2 on the
refurbished Hubble Space Telescope (HST). This is accomplished by means of
reddening-free parameters and a comparison with stellar population synthesis
tracks to estimate the intrinsic luminosity and age and hence the mass of each
cluster. We find that the mass function of the young star clusters (with ages
<~ 160 Myr) is well represented by a power law of the form psi(M) ~ M^{-2} over
the range 10^4 < M < 10^6 solar masses. This result may have important
implications for our understanding of the origin of globular clusters during
the early phases of galactic evolution.
