The volume assembles an encyclopedic survey of the known world and its living inhabitants, moving from detailed regional geography and descriptions of seas, rivers, islands, and peoples to extended treatments of humanity, its generation, anatomy, and the origins and inventions of arts. Subsequent books catalog terrestrial animals—their habits, capture, and uses—followed by comprehensive observations on fish and marine creatures, their sizes and behaviors. Accounts mix naturalistic description, reported marvels, medicinal uses derived from animals, and travel and secondhand reports, organized as topical chapters intended as a practical compendium of natural and human phenomena.