Introduction I. Structure of articular cartilage Microscopical appearance and organization of articular cartilage surfaces Scanning electron microscope study of normal human articular cartilage Sequential changes in superficial defects in articular cartilage studied with the scanning electron microscope Cartilage fibrillation versus ink-staining patterns: Scanning electron microscope study Stain distribution with alcian blue in articular cartilage I. Short communications Some new morphological data on histogenesis of articular cartilage Matrix structure in articular cartilage Three-dimensional observations of articular cartilage matrix Ultrastructural aspects of normal and osteoarthrotic cartilage Scanning electron microscopy of human osteoarthrotic cartilage II. Chemistry of the matrix Structure and stability of proteoglycan aggregates Structure of cartilage proteoglycans Interaction of cartilage collagen fibrils and proteoglycans: Application of fluorescent labelling techniques for assay of enzymes degrading cartilage Chain composition of pepsin-solubilized collagen from normal bovine and osteoarthrotic human articular cartilage Passive agglutination method using collagen-coated tanned sheep erythrocytes to demonstrate collagen-glycosaminoglycan interaction II. Short communications Procollagen of chick xyphoid cartilage Nature and location of crosslinks in cartilage collagen Discontinuous nature of the protein-keratan sulphate core of cartilage proteoglycan Concentration, distribution, and metabolism of glycosaminoglycans in different layers of normal human articular cartilage Variations in glycosaminoglycans with surface site in human knee joint cartilage Charged group behaviour in cartilage proteoglycans in relation to pH Equilibria of calcium and phosphate ions in human articular cartilage III. Metabolism Nucleotide sugar metabolism in glycosaminoglycan biosynthesis Biosynthesis of proteoglycans in cartilage Cartilage turnover III. Short communications Effect of in vitro incubation on distribution and synthesis of glycosaminoglycans of articular cartilage Effect of antiproteoglycan serum and Hyaluronidase on metabolic functions of calf cartilage cells in vitro Overlabelling of chondroitin sulphate (ChS) chains after application of specific inhibitors of their biosynthesis Synthesis of cerebroside sulphatides in human articular cartilage Circadian rhythms in the excretion of urinary acid glycosaminoglycans IV. Enzymes and degradation Enzymes involved in degradation of cartilage in osteoarthrosis Breakdown of protein-polysaccharide complexes by cartilage proteases The possible function of lysozyme in cartilage metabolism IV. Short communications Evidence for secretion of a proteolytic enzyme from rheumatoid pannus and synovium Action of rheumatoid synovial collagenase on cartilage collagen Mechanism of cartilage and synovial fluid hyaluronate degradation by polysaccharidases Response of articular cartilage in organ culture to growth hormone Release and degradation of sulphated proteoglycans and collagen from the cell layer of human chondrocytes Studies on cartilage vascularization V.A. Functional properties Fluid transport in cartilage Fundamental fluid transport mechanisms through articular cartilage An approximate equation for weeping lubrication, solved with an electrical analogue Purification and properties of articular lubricant An overall view of synovial joint lubrication V.A. Short communications Proteins associated with hyaluronic acid Formation of lubricating monolayers at the cartilage surface Lubrication defect of immobilized connective tissue matrices: Study of the biomechanical and biochemical characteristics of normal and immobilized rabbit knee V.B. Functional properties Some aspects of the mechanical behaviour of articular cartilage In vitro fatigue testing of articular cartilage Mechanical properties of articular cartilage and their relationship to matrix degradation and age Contact pressures in the loaded cadaver human hip V.B. Short communications A simple mechanical model of articular cartilage A new approach to the determination of the elastic modulus of articular cartilage Wear properties of articular cartilage Load bearing function of the menisci of the knee joint VI. Pathogenesis of osteoarthrosis Pathogenesis of osteoarthrosis: An hypothesis Articular cartilage lesions in the Liverpool population Contribution to the study of the initial stage of cartilage degeneration Bone density in osteoarthrosis Mechanical factors in the aetiology of osteoarthrosis VI. Short communications Histological changes in osteoarthrotic femoral head cartilage Cartilage of the patella and its degeneration: Topographical variation of the glycosaminoglycan content Ultrastructural and histological studies on articular cartilage in experimental osteoarthrosis Proteoglycan aggregation in early experimental osteoarthrosis Experimentally-induced osteoarthrosis in the dog: Collagen biosynthesis in control and fibrillated articular cartilage Experimental evidence for an injury threshold for articular cartilage Early loss of glycosaminoglycans in experimental haemarthrosis in dogs Osteocyte death in rheumatic diseases Differentiation and maintenance of articular (secondary) cartilage on avian membrane bones Immunocytochemical and historical studies of a reversible transformation of chondrocytes in degraded cartilage matrix to a fibroblast-like morphology Conclusions of a working party of morbid anatomists Bibliography