Subnuclear phenomena analyticity and algebraic properties in particle physics, models for deep inelastic electron-proton scattering, developments of the quark model, status of weak interactions, baryonic and mesonic resonances ... ; 1969 International School of Physics "Ettore Majorana", a MPI-NATO advanced study institute, Erice, July 3-19. B Review lectures, seminars on specialized topics, closing lecture