  Let a=(p_1^{q_1}, ..., p_r^{q_r}) be a partition and a'=({p_1'}^{q_1'}, >...,
{p_r'}^{q_r'}) be its conjugate.
  We will prove that if q_i, q_i > 1 for all i, then any irreducible subvariety
X of Gr(m,n) whose homology class is an integral multiple of the Schubert class
[\sigma_a] of type a is a Schubert variety of type a.
