  We study a nonlinear Glauber-Fock lattice and the conditions for the
excitation of localized structures. We investigate the particular linear
properties of these lattices, including linear localized modes. We investigate
numerically nonlinear modes centered in each site of the lattice. We found a
strong disagreement of the general tendency between the stationary and the
dynamical excitation thresholds, and we give a new definition based on both
considerations.
