  To distinguish between the different models proposed to understand the excess
of faint field counts over the predictions from non-evolving models, a number
of redshift surveys have been undertaken. The answer has not arrived yet due to
the high rate of incompleteness achieved. Un-identified galaxies have been
shown to be bluer than identified ones. In this paper, it is argued that some
of these galaxies could be "quiescent" dwarfs, still quite blue, but with
featureless spectra.
