Within a single captivating narrative, John Bonner combines an intensely personal memoir of scientific progress and an overview of what we now know about living things. Bonner, a major participant in the development of biology as an experimental science, draws on his life-long study of slime molds for an understanding of the life cycle-the foundation of all biology. In an age of increasing specialization and fragmentation among subfields of biology, this is a unique work of reflection and integration. Originally published in 1993. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These editions preserve the original texts of these important books while presenting them in durable paperback and hardcover editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.