  The large statistics of millions of hadronic Z0 decays, accumulated by the
four LEP experiments between 1989 and 1995, allowed for detailed investigations
of the fragmentation process. Inclusive Lambda_b baryons and Lambda hyperons at
intermediate and high momentum have been found to show longitudinal
polarization. This may be related to the primary quark and antiquark
polarization and the hadronization mechanism which produces the leading
baryons. Helicity density-matrix elements have been measured for a variety of
vector mesons produced inclusively in hadronic Z0 decays. The diagonal elements
of some of the light mesons and the D*+- show a preference for a helicity-zero
state if the meson carries a large fraction of the available energy. The
mechanism which produces such spin alignment in the non-perturbative
hadronization of the primary partons to the vector mesons is so far
unexplained. For the B* the results are consistent with no spin alignment,
which is expected in a picture based on HQET. For some meson species
non-diagonal elements have been measured indicating coherence phenomena due to
final-state interaction between the primary quark and antiquark.
