An investigation of the role of protein-polysaccharide complexes of the nucleus pulposus in intervertebral disc prolapse and degeneration is presented. Investigative techniques include roentgenographic crystallography, infrared spectroscopy, polarizing and electronmicroscopy, direct biochemical investigations, and immunologic studies. A visual representation is provided of the hypothesis that there is a chemical basis for disc degeneration and prolapse, and that the process may be a cyclic one.