Note on the Resemblances and Differences in the Structure and the Development of the Brain in Man and Apes

The essay surveys a long dispute about whether ape and human brains are fundamentally different, concluding that detailed comparative anatomy reveals the same principal structures and corresponding gyri and sulci in higher apes and humans. It notes consistent quantitative differences, such as larger absolute and relative cerebral hemispheres in humans, distinctive frontal‑lobe contours, and a greater incidence of secondary convolutions, while showing that features like the temporo‑occipital fissure vary in degree rather than kind. Emphasis is placed on intra‑ and interspecific variability, including bridging convolutions and asymmetry, which weakens the taxonomic value of any single sulcal character and portrays a continuum of resemblance and difference.