  We show that recently constructed invariants of 3-dimensional manifolds and
of hyperkaehler manifolds (L.Rozansky and E.Witten, hep-th/9612216) come from
characteristic classes of foliations and from Gelfand-Fuks cohomology. In
particular, any symplectic foliation gives invariants of 3-manifolds.
  Our preprint has many intersections with the preprint alg-geom/9704009 by
M.Kapranov.
