  We calculate the two-point correlation function and magnetic susceptibility
in the anisotropic 2D Ising model on a lattice with one infinite and the other
finite dimension, along which periodic boundary conditions are imposed. Using
exact expressions for a part of lattice form factors, we propose the formulas
for arbitrary spin matrix elements, thus providing a possibility to compute all
multipoint correlation functions in the anisotropic Ising model on cylindrical
and toroidal lattices. The scaling limit of the corresponding expressions is
also analyzed.
