Simi larly, the term "autowaves" de­ notes propagation effects - including waves - in active media, which provide spa­ tially distributed energy sources and thus may compensate dissipation. According to its definition, Synergetics is concerned with systems that produce macroscopic spatial, temporal, or functional structures. Autowaves are·a specific, yet very important, case of spatio-temporal structures. The term "autowave" was coined in the Soviet Union in analogy to the term "auto-oscillator". This is - perhaps too literal - translation of the Russian word "avto-ostsillyatory" (= self­ oscillator) which in its proper translation means "self-sustained oscillator". These are oscillators, e. g. , clocks, whose internal energy dissipation is compensa­ ted by a (more or less) continuous power input. Simi larly, the term "autowaves" de­ notes propagation effects - including waves - in active media, which provide spa­ tially distributed energy sources and thus may compensate dissipation. An example which is now famous is represented by spiral or concentric waves in a chemically active medium, undergoing the Belousov-Zhabotinsky reaction. This book provides the reader with numerous further examples from physics, chem­ istry, and biology - e. g. , autowaves of the heart. While the Belousov-Zhabotinsky reaction is now widely known, a number of very important results obtained in the Soviet Union are perhaps less well known. I am particularly glad that this book may help to make readers outside the Soviet Union acquainted with these important exper­ imental and theoretical findings which are presented in a way which elucidates the common principles underlying this kind of propagation effects. Professor V.