  We review selected measurements of the galaxy luminosity function including
the global field, the local group, the local sphere, nearby clusters (Virgo,
Coma and Fornax) and clusters in general. We conclude that the overall cluster
luminosity function is consistent with the global luminosity function over the
magnitude range in common (-22 < M_B -5logh_0.68 < -17). We find that only in
the core regions of clusters (r < 300 kpc) does the overall form of the
luminosity function show significant variation. However when the luminosity
function is subdivided by spectral type some further variations are seen. We
argue that these results imply: substantial late infall, efficient
star-formation suppression, and the confinement of mass-changing evolutionary
processes to the core regions only.

Astrophysics