This work investigates many ties between the biological sciences and the building arts. Natural building materials, such as wood and limestone, originate in biological processes and much architectural ornament borrows from botany and zoology. Art historian George Hersey draws analogies between building types and animal species. He examines the relationship between physical structures and living organisms, from bridges to mosques and from molecules to mammals. Insects, mollusks and birds are given separate chapters, and three final chapters focus on architectural form and biological reproduction. Hersey also discusses architecture in connection with the body's interior processes and shows how buildings may be said to reproduce, adapt and evolve, like other inanimate or "nonbiotic" entities such as computer programs and robots.