Color enhanced scanning electron micrographs of a guinea pig's organ of Corti. The organ of Corti (or spiral organ) is the organ in the inner ear of mammals that contains auditory sensory cells, or "hair cells." The accompanying low-power scanning micrograph presents a surface view of the organ of Corti in the third turn of the guinea-pig cochlea. Three rows of outer hair cells are shown, each bearing a V-shaped array of sensory hairs. The inset shows at high magnification the hairs on two cells from the first row in the second turn of the organ of Corti. Their relative size can be judged by comparison with the microvilli on neighboring cells.