  The constituent nature of candidate gluonic mesons can be studied by
comparing their production in quark and gluon jets. The production rate for
such mesons depends on the colour confinement processes at the end of the
perturbative evolution. Whereas we expect enhanced production of hybrids in the
fragmentation region of a gluon jet, the rate for glueballs depends on the
relative importance of colour triplet and colour octet neutralization. These
neutralization processes can be studied independently in events with large
rapidity gaps. If octet processes turn out important the recently suggested
lightest J^{PC}=0^{++} glueball with mass around 1000 MeV should become visible
already in the spectrum of the leading charged particle pairs.
