  It is shown that the existence of left-right asymmetry in single-spin
inclusive Lambda production, together with the characteristic features of the
data, should be considered as another clear signature for the existence of
orbiting valence quarks in polarized nucleons. Predictions for other hyperons
are made. It is pointed out that measurements of such asymmetries are very
helpful not only for probing the spin structure of the nucleons but also for
studying the production mechanisms of the hyperons.
