[Columnar organization of pyramidal cells of the visual cortex in the albino rat]

1. The arrangement of the pyramidal cells of the visual cortex has been investigated by light and electron microscopy in 36 albino rats. 2. It was shown, that the apical dendrites form bundles. The number of dendrites per bundle is about 5 in the lower lamina Vb and 7.5 in the upper lamina Va, the diameter of bundles is about 25.7 mum. The average distance between the centers of bundles is 76,4 mum, and between the peripheries 53.1 mum. 3. The results are compared with physiological and morphological findings. It was shown, that there is an agreement of diameter of bundles und their lateral branching dendrites with diameters of columns of cells and of terminal branchings of specific afferents. 4. The morphological results are graphically reconstructed.