In this Very Short Introduction, Terrence Allen and Graham Cowling offer an illuminating account of the nature of cells--their basic structure, forms, division, signaling, and programmed death. Allen and Cowling start with the simple "prokaryotic" cell--cells with no nucleus--and show how the bodies of more complex plants and animals consist of billions of "eukaryotic" cells, of varying kinds, adapted to fill different roles--red blood cells, muscle cells, branched neurons. The authors also show that each cell is an astonishingly complex chemical factory, the activities of which we have only...