Washburn's best-known work and, arguably, her most significant contribution to psychology was her influential textbook, "The Animal Mind: A Textbook of Comparative Psychology." Originally published in 1908, this book compiled research on experimental work in animal psychology. Her range of literature was considerable, resulting in a bibliography of 476 titles in the 1st edition, which eventually grew to 1683 titles by the 4th edition. "The Animal Mind" covered a range of mental activities, beginning with the senses and perception, including hearing, vision, kinesthetic, and tactual sensation. The books' later chapter focused upon consciousness and higher mental processes. However, the dominant focus of the book is animal behavior.