  The 2-dimensional density of states of an electron is studied for a
Poissonian random distribution of point vortices carrying $\alpha$ flux in unit
of the quantum of flux. It is shown that, for any given density of impurities,
there is a transition, when $\alpha\simeq 0.3-0.4$, from an "almost free"
density of state -with only a depletion of states at the bottom of the spectrum
characterized by a Lifschitz tail- to a Landau density of state with sharp
Landau level oscillations. Several evidences and arguments for this transition
-numerical and analytical- are presented.
