  We calculate the parton distributions for both polarized and unpolarized
octet and decuplet baryons, using the MIT bag, dressed by mesons. We show that
the hyperfine interaction responsible for the $\Delta - N$ and $\Sigma^0 -
\Lambda$ splittings leads to large deviations from SU(3) and SU(6) predictions.
For the $\Lambda$ we find significant polarized, non-strange parton
distributions which lead to a sizable $\Lambda$ polarization in polarized,
semi-inclusive $ep$ scattering. We also discuss the flavour symmetry violation
arising from the meson-cloud associated with the chiral structure of baryons.
