  We present a direct computation of the period integrals on degenerate
Seiberg-Witten curves for supersymmetric QCD, and show how these periods
determine the changes in the quantum numbers of the states, when passing from
the weak to the strong-coupling domains in the mass moduli space of the theory.
The confinement of monopoles at strong coupling is discussed, and we
demonstrate that the ambiguities in choosing the way in the moduli space do not
influence to the physical conclusions on confinement of monopoles in the phase
with the condensed light dyons.
