  Globular clusters with composite color-magnitude diagrams, such as NGC 1851,
NGC 2808 and Fornax No. 3, might have formed by mergers. It is suggested that
each of these objects had two parent clusters, one with a red horizontal branch
and another with a blue horizontal branch. Such mergers could have occurred if
both ancestral objects were originally members of a single dwarf spheroidal
galaxy in which the internal velocity dispersion was low.
