The 13 lectures from a course in sub-atomic systems for graduate and post-doctorate physics students, held in Dronton, The Netherlands, in August 1993. They address the hadronic structure starting at low energies with meson production and nucleon resonance excitation in lepton and hadron scattering from nucleons and nuclei, high-energy muon scattering results in relation to the quark and gluon content of the nucleon and spin structure, and the quest for the quark-gluon plasma in ultra-relativistic heavy-ion collisions. Reproduced from typescripts. Annotation copyright Book News, Inc. Portland, Or.