A scientific survey of the great apes presents historical accounts of human encounters, detailed descriptions of external form and internal anatomy, and systematic comparisons between ape and human structures. It examines variation within ape groups, geographical distribution, natural habits, and indigenous names, then addresses life in captivity and practical observation. Numerous illustrations and anatomical plates support analyses of skulls, skeletons, muscles, and brains. The author discusses taxonomic placement, assesses degrees of anthropomorphism attributed to different species, and closes with a concise synthesis and further reflections on morphology and classification.