  An explanation of the difference in the values of the apparent $f/d$ ratios
for the S- and P- wave amplitudes of nonleptonic hyperon decays is proposed.
The argument is formulated in the framework of the standard pole model with
$(56,0^{+})$ ground-state and $(70,1^{-})$ excited baryons as intermediate
states for the P- and S- waves respectively. Under the assumption that the
dominant part of the deviation of $(f/d)_{P-wave}$ from $-1$ is due to large
quark sea effects, $SU(3)$ symmetry breaking in energy denominators is shown to
lead to a prediction for $(f/d)_{S-wave}$ which is in excellent agreement with
experiment. This corroborates our previous unitarity calculations which
indicated that the matrix elements $<B|H^{p.c.}_{weak}|B'>$ of the parity
conserving weak Hamiltonian between the ground-state baryons are characterized
by $f_{0}/d_{0} \approx -1.6$ or more. A brief discussion of the problem of the
relative size of S- and P- wave amplitudes is given. Finally, implications for
weak radiative hyperon decays are also discussed.
