  We study how fermion number conservation fails in fermion number preserving
regularization schemes. We show that the fermion number have to be carried by
the gauge field configurations with non-zero winding number in this scheme and
this fermion number is not conserved in the presence of instantons. We also
consider other types of regularization scheme which have different global
symmetries. In particular, we point out that the fermion number is conserved in
the lattice chiral gauge theories with the Wilson-Yukawa coupling.
