This new interdisciplinary study investigates the scientific and cultural roots of contemporary conceptions of the network, including computer information systems, the human nervous system, and communication technology. Laura Otis demonstrates that those roots are centuries old, not a modern conception. She shows how nineteenth-century neurobiologists, engineers, and fiction writers influenced each other's ideas about communication. Placing our own comparisons of nerve and computer networks in perspective, Otis explores their emergence in early analogies linking nerves and telegraphs.