"A Bilateral Division of the Parietal Bone in a Chimpanzee; with a Special Reference to the Oblique Sutures in the Parietal" by Aleš Hrdlička is a scientific publication produced in the early 20th century. This work is a detailed anatomical study focusing on the unique case of a chimpanzee skull, specifically examining the bilateral division of the parietal bones and implications for understanding cranial sutures in primates. The book serves as an important contribution to the field of anthropology and anatomy. In this document, Hrdlička presents a thorough analysis of the parietal bone's division in a nine-year-old male chimpanzee, captured in West Africa and later preserved at the American Museum of Natural History. The author describes the first complete divisions of the parietal observed in a chimpanzee, noting their distinct characteristics, as they do not align with previously documented cranial sutures in humans or other primates. Detailed measurements, descriptions of the skull's morphology, and comparative observations against other specimens enrich the study, culminating in a discussion about abnormal cranial conditions and their developmental significance. Ultimately, Hrdlička's insights provide a deeper understanding of cranial anatomy and evolutionary biology among primates. (This is an automatically generated summary.)