The term area 10 of Walker refers to a subdivision of the frontal lobe of the macaque defined on the basis of cytoarchitecture. It is "narrow cortex with a well-developed [internal granular layer] and medium-sized pyramidal cells in the outer part of the fifth layer. The remainder of the fifth and sixth layers are poorly developed." Walker regarded the most likely cytoarchitectural homologue in the area 10 of Brodmann (human); he did not regard it as a cytoarchitectural homologue of area 10 of Brodmann (guenon) ( Walker-1940 ).