Synthesizing the theoretical and experimental advances in pion-nucleon interactions over approximately the last twelve years, the authors offer here a timely account of the hadronic interactions of pions and nucleons and of the structure of nucleons. Because of the hadronic SU3 symmetry, the book also treats the structure of baryons in general, and so contains much material external to the specific field of pion-nucleon interactions. Thus the book's subject can be stated as the hadronic structure of baryons as illustrated particularly by pion-nucleon interaction. Following an introductory discussion of isotopic spin, the authors proceed to chapters that treat low energy pion scattering by nucleons and the photoproduction of pions; forward and fixed momentum transfer dispersion relations; analytic properties of scattering amplitudes; formation of nucleon resonances; symmetries and classification of particles and resonances; current algebra, sum rules, and superconvergence relations; scattering at higher energies; pion-nucleon dynamics; pion-nucleon inelastic scattering; and the form factors of the nucleon and the pion. Each chapter is followed by abundant references to the original literature. The level of the writing is suitable for students at the graduate level, and the presentation is even and self-contained. On balance, the authors have prepared a useful consolidation and review of this difficult and changing area of investigation. Originally published in 1973. The uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These editions preserve the original texts of these important books while presenting them in durable paperback and hardcover editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.