  We discuss a possible delay experienced by protogalaxies with low column
density of gas in forming stars over large scales. After the hydrogen has
recombined, as the external ionizing UV flux decreases and the metal abundance
$Z$ increases, the HI, initially in the warm phase ($T\simgt 5000$ K), makes a
transition to the cool phase ($T\simlt 100$ K). The minimum abundance $Z_{min}$
for which this phase transition takes place in a small fraction of the Hubble
time decreases rapidly with increasing gas column density. Therefore in the
``anemic'' disk galaxies, where $N_{HI}$ is up to ten times smaller than for
normal large spirals, the onset of the cool HI phase is delayed. The onset of
gravitational instability is also delayed, since these objects are more likely
to be gravitationally stable in the warm phase than progenitors of today's
large spiral galaxies. The first substantial burst of star formation may occur
only as late as at redshifts $z \sim 0.5$ and give a temporary high peak
luminosity, which may be related to the ``faint blue objects". Galaxy disks of
lower column density tend to have lower escape velocities and a
starburst/galactic fountain instability which decreases the gas content of the
inner disk drastically.
