The histology and histochemistry of the column body wall of the sea anemone Isactinia olivacea (Hutton, 1878) are described. The ectodermal supporting cells bear non-motile projections at the free surface. These projections may assist in the shedding of unwanted secretions from the surface of the animal. Unicellular ectodermal glands show a wide variation of morphology and type of secretion. Both proteinaceous and polysaccharide containing glands are of wide occurrence. Mesogloeal fibres have staining properties characteristic of collagen. Cells are abundant in the mesogloea, and contain protein, polysaccharide and lipid granules; their role in the mesogloea is discussed. The endoderm is composed mostly of flagellated epitheliomuscular cells; it is regarded as being trilaminar: the epithelial portions of the cells form one layer, and the circular muscle fibres form another; in between these two is a fluid filled layer which it is suggested has a hydrostatic function. Proteinaceous and polysaccharide containing gland cells are present between the epitheliomuscular cells.