  The globular cluster system of a typical spheroidal galaxy makes up about
0.25% of the total galaxy mass (McLaughlin 1999). This is roughly the same mass
fraction as contained in the nuclear star clus- ter (or stellar nucleus)
present in most nearby low-mass galaxies. Motivated by this "coincidence", this
Letter discusses a scenario in which globular clusters of present-day galaxies
are the surviving nuclei of the dwarf galaxies that - according to the
hierarchical merging paradigm of galaxy forma- tion - constitute the "building
blocks" of present-day massive galaxies. This scenario, which was first
suggested by Freeman (1993), has become more attractive recently in the light
of studies that demonstrate a complex star formation history in a number of
massive globular clusters.
