  We have stumbled upon a remarkable empirical feature of central meson
production which separates established $q\bar{q}$ mesons from glueball
candidates. This does not appear to have been noted previously and we have no
simple explanation for it. We suggest that glueballs and $q\bar{q}$ of the same
$J^{PC}$ are distinguishable due to their boson versus fermion internal
structure and that this leads to a different topology for central production of
glueballs and $q\bar{q}$. Upon application of this test to data from the WA102
experiment we find that the $f_0(1500)$ and the $f_{2}(1900)$ show behaviour
consistent with glueballs and opposite to that exhibited by established
$q\bar{q}$ states.
