  Galactic and extragalactic abundance studies of H II regions, planetary
nebulae, and supernova remnants are compiled and their implications briefly
reviewed. Galaxy global metallicity appears to be related directly to total
mass and morphology, while gradient slopes are uncorrelated with these
parameters, although barred spirals tend to have flatter profiles than
non-barred spirals. N/O behavior is consistent with primary, then secondary,
production of N as metallicity increases, and empirical evidence for a
metallicity-sensitive C yield is seen. Metallicity-invariant primary production
mechanisms are suggested for S, Ne, Ar, and O.
