This non-fiction scientific volume examines the rat as a central model in laboratory research, combining practical guidance with biological observation. Associated with Ferris and Griffith, the second edition reflects mid-twentieth-century experimental priorities, likely addressing anatomy, breeding, care, handling, and the rat’s use in physiology, pathology, nutrition, and pharmacology. Its structure appears directed toward researchers, technicians, and students who required a standardized reference for animal-based investigation. The book’s contribution lies in documenting methods and assumptions that shaped early biomedical practice while also illuminating the historical development of laboratory animal science.