  The gluon propagator in the Landau gauge is calculated in quenched QCD on a
large lattice (32^3x64) at beta=6.0. In order to assess finite volume and
finite lattice spacing artefacts, we also calculate the propagator on a smaller
volume for two different values of the lattice spacing. New structure seen in
the infrared region survives conservative cuts to the lattice data, and serves
to exclude a number of models that have appeared in the literature.
