With the introduction of antibiotics acute inflammatory disease has ceased to be the dominant problem in general medical practice and its place is now increasingly occupied by chronic inflamma tory disease of which the rheumatic diseases constitute the most important group. lwo aspects of these diseases need to be consid ered, their aetiology and their pathogenesis. In some respects the latter is more important since even when the aetiology is known, as for example the haemolytic streptococcus in rheumatic fever, the mechanism by which the infecting agent accomplishes the development of the...