This volume examines cells set aside during development for use later in ontogeny or in adult life. There is no single term for such cells. The cells explored fall within several major categories - stem cells, set-aside cells (in echinoderm larvae), imaginal discs in insects such as Drosophila, meristems (plants), blastemata (regeneration in amphibians), neoblasts (regeneration in planarians). The book compares and contrasts these cell types and the environments (niches) in which they operate with the aim of unravelling any relationships between them, between their activation in development, and in their evolution. Key Features Explores the nature of deferred-use cells in evolutionary and developmental context. Reviews the mechanisms of development of set-aside cells, such as stem cells, meristems, and imaginal discs. Provides phylogenetic overview of different types of deferred-use cells. Compares and contrasts different theories on the origin of deferred-use cells. Related Titles Calegari, F. & C. Waskow, eds. Stem Cells: From Basic Research to Therapy (ISBN 978-1-4822-0775-0) Cabral, J. M. S. & C. L. da Silva, eds. Bioreactors for Stem Cell Expansion and Differentiation (ISBN 978-1-4987-9590-6) Kong, H., A. J. Putnam, & L. B. Schook, eds. Stem Cells and Revascularization Therapies (ISBN 978-1-4398-0323-3) Schaffer, D., J. D. Bronzino, & D. R. Peterson, eds. Stem Cell Engineering: Principles and Practices (ISBN 978-1-4398-7204-8)