  We have measured the differential production cross sections as a function of
scaled momentum x_p=2p/E_cm of the identified hadron species pi+, K+, K0, K*0,
phi, p, Lambda0, and of the corresponding antihadron species in inclusive
hadronic Z0 decays, as well as separately for Z0 decays into light (u, d, s), c
and b flavors. Clear flavor dependences are observed, consistent with
expectations based upon previously measured production and decay properties of
heavy hadrons. These results were used to test the QCD predictions of Gribov
and Lipatov, the predictions of QCD in the Modified Leading Logarithm
Approximation with the ansatz of Local Parton-Hadron Duality, and the
predictions of three fragmentation models. Ratios of production of different
hadron species were also measured as a function of x_p and were used to study
the suppression of strange meson, strange and non-strange baryon, and vector
meson production in the jet fragmentation process. The light-flavor results
provide improved tests of the above predictions, as they remove the
contribution of heavy hadron production and decay from that of the rest of the
fragmentation process. In addition we have compared hadron and antihadron
production as a function of x_p in light quark (as opposed to antiquark) jets.
Differences are observed at high x_p, providing direct evidence that
higher-momentum hadrons are more likely to contain a primary quark or
antiquark. The differences for pseudoscalar and vector kaons provide new
measurements of strangeness suppression for high-x_p fragmentation products.
