Proton Polarization in Multiple Pion Production as a Consequence of the Isobar Model

The isobar model for the system p + pi /sup +/ is in reasonable accord with the gross features of the momentum distribution for pions emitted in proton- proton collisions, and also in pion photoproduction from nucleons. Some consequences which follow for near-threshold production of the isobar by piors if the model is taken seriously are sbown. (A.C.)