  The current observational evidences suggest there are about hundred billion
galaxies in the observable universe and within each, on an average, about
hundred billion stars. But no cosmological model indicates as to why there are
these many galaxies and stars. In this paper we invoke the property of
non-irrotational hydrodynamic flow in order to explain how a primordial
rotation (as considered in a recent paper) of the universe broken up into
vortex line structures, can indeed lead to formation of a large number of
galactic structures and these in turn can lead to equally large number of stars
within each galaxy.
