A 1922 research note by W. Lawrence Balls and H. A. Hancock on the microscopic structure of the cotton hair cell wall. It describes the cuticle, primary wall, and secondary wall, and reports a spiral fibrillar structure (pit spirals) running through the growth rings. It relates this structure to the external convolutions of the hair, using dated boll samples, swelling and pressure techniques, and convolution maps. The note ends with eight numbered conclusions and a plate of nine micrographs of Sakel cotton hairs.