Caviness: " The parietal fields are relatively wide, second in width only to the frontal fields. Their cell and fiber densities are greatest of all regions of the neocortex. The aggregate of layers I1 through IV is relatively wide, composing the outer one- third of the cellular zone of the cortex. In general there is no differentiation of sep- arate layers 11 and 111 in the supragranular zone. Layer IV is more prominent in the parietal region than in all other cortical regions. Its cells are densely packed, small and darkly staining. Layer V is narrower than in the frontal fields and is distinctive in having relatively hypocellular sublami- nas V a and, to a lesser extent, Vc. Pyram- idal cells, becoming progressively smaller in medial to lateral progression, are con- centrated in Vb. As in the frontal fields, layer VI is wide. However, layer VI of parie- tal cortex, unlike that of the frontal fields, is differentiated into two sublaminas. The outer, VIa, is composed of globular cells. The inner or basal sublamina VIb is com- posed of fusiform cells aligned tangentially, parallel to the coronal plane. The tangen- tial fiber strata in layers 111, IV, V and VI are denser than in any other cortical region. The radial fiber pattern, both as single fibers and fiber fascicles, is also particu- larly well developed. Only a few tangential- ly coursing fibers are impregnated in lay- er I. "
Summary:
This change is a minor edit.
Username: