  The distribution and the correlations of the small eigenvalues of the Dirac
operator are described by random matrix theory (RMT) up to the Thouless energy
$E_c\propto 1/\sqrt{V}$, where $V$ is the physical volume. For somewhat larger
energies, the same quantities can be described by chiral perturbation theory
(chPT). For most quantities there is an intermediate energy regime, roughly
$1/V<E<1/\sqrt{V}$, where the results of RMT and chPT agree with each other. We
test these predictions by constructing the connected and disconnected scalar
susceptibilities from Dirac spectra obtained in quenched SU(2) and SU(3)
simulations with staggered fermions for a variety of lattice sizes and coupling
constants. In deriving the predictions of chPT, it is important to take into
account only those symmetries which are exactly realized on the lattice.
