A review of American and English literature on rheumatism and arthritis was last published in this journal in 1964. An excellent sequel to that review has appeared elsewhere (2). It is not our purpose to duplicate such an exhaustive discussion and critique of the literature but rather to present the highlights of recent advances in clinical rheumatology, without attempting to be all-inclusive. ETIOLOGY A number of factors, either alone or in combination, have been implicated in the causation of rheumatoid arthritis (RA). Because both the disease and positive serologic reactions appeared to occur more frequently in family members