Results from the analysis of π −−N interactions at 17.2 GeV/ c in photographic emulsions are presented. From the frequency of odd and even shower multiplicities, evidence is presented to support the conclusion of Davis et al. that the surface of heavy nuclei is rich in neutrons. Inelasticities for small and large shower multiplicities are deduced. Discrepancies in inelasticities obtained in emulsions and bubble chambers are attributed to the differences in the momentum selection criteria. It is concluded that the symmetry in angular distributions of pions in gp- π system in small multiplicity events, is accidental. The frequency of K mesons is indirectly estimated from the energy balance, and is found to be consistent with direct observations, in the hydrogen bubble chamber, at similar energy. The frequency of neutral pions is deduced for various groups of shower multiplicities. In very large multiplivity events ( n s ⩾ 8), negligible numbers of π o are found to be produced. The transverse momentum ( P t) distribution for pions is found to be in agreement with Hagedorn's theory as well as with the formula of Cocconi et al. The P t distribution for protons, on the other hand, is inconsistent with Hagedorn's theory.