The Last Link: Our Present Knowledge of the Descent of Man

The author surveys evidence for human descent, synthesizing comparative anatomy, embryology, and paleontology to outline a hypothetical ancestral chain from simple protoplasmic organisms through unicellular stages, colonial and blastula forms, gastrula and primitive bilateral animals, up to higher invertebrate and vertebrate stages. He explains embryological recapitulation, cell theory, and proposed factors driving evolution, and summarizes geological time scales as they relate to transformation. The volume also offers biographical sketches and critical notes on earlier naturalists and anatomists, and presents a concise sequence of developmental stages used to illustrate how living organisms and fossils may represent successive links in human ancestry.