This work presents a systematic, observational study of plant structure and function, describing the internal organization of seeds, roots, stems, leaves, flowers, fruits, and seeds as revealed by close inspection and a microscope. It maps tissues and organs, explains the movement of sap and air, and analyses the generation and distribution of plant fluids and substances such as milks, oils, and salts. Additional lectures examine leaf and flower anatomy, coloration, tastes, and soluble salts, and the text includes comparative tables and explanatory notes to support a mechanical and physiological account of vegetation.