This well-illustrated monograph is the first summary in English of L.V. Polezhaev's important but lesser known work on the regenerative phenomena in mammalian forms, conducted since World War II. During this period Soviet research underwent a pronounced shift in emphasis from basic biological studies based primarily upon amphibians to more practically oriented problems in mammalian systems. Polezhaev's experimentation underwent a corresponding shift, but the focus on restoration of lost regenerative capacity was retained since his earlier work, which is also reviewed here, on limb regeneration in frogs. Following a theoretical discussion, the monograph centers upon the author's most profound innovations: a successful method for producing bone to heal large skull defects, original research on heart regeneration, and trials in the restoration of limb regeneration following X-irradiation.