Underlying the epithelium, there is a layer of basal lamina which separates the epithelium from the major part of the pillar system. The pillar system is a collective term for the pillar cells and blood capillaries. The pillar cells are the main body of this system which supports the lamella. The pillar cell has a targe nucleus occupies the greater part of the main cell body with irregular outline and heterochromatic clumps. The cytoplasm has few mitochondria and poor endoplasmic reticulum. Four cytoplasmic projections known as pillar arms, two arms on each side of the cell extend to overlap with the arms of the next pillar cell to form a space; (blood lacuna) in which blood cells move (Figs. 2 & 11).