  A simple model for the dust media describing evolution of the system like
spiral galaxy is considered. In contrast to previous considerations we show
that the initial density fold should be quasi-one-dimensional (bar-like)
instead of disc-like. The disc component of the galaxies appears only during
the evolution. The model naturally reproduces some essential features of the
galaxies. In particular, it reproduces all the observed typical forms of the
rotation curves for the spiral galaxies with a characteristic minimum and
plateau. It appears that the plateau corresponds to escaping the matter
(external spiral arms, due to initial conditions, have too large velocities to
be confined by the gravitational field of the galaxy). Such a scenario of the
galaxy evolution leads to the conclusion that the hypothesis of the dark matter
is not necessary (at least, for the spiral galaxies).
