The globular cluster system of a typical spheroidal galaxy makes up about 0.25 % of the total galaxy mass ( 31 ) .
This is roughly the same mass fraction as contained in the nuclear star cluster ( 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 formation - constitute the “ building blocks ” of present-day massive galaxies .
This scenario , which was first suggested by ( 21 ) , has become more attractive recently in the light of studies that demonstrate a complex star formation history in a number of massive globular clusters .