A CONSIDERABLE amount of new information concerning leptospiral infections has been gained recently, principally through work done in Europe and Australia. Laboratory investigations have led to the identification of new strains; epidemiologic observations have thrown light on the natural reservoirs of infection, and clinicians have described several different expressions of leptospiral infection in man. In America, there seems to have been a curious lack of interest in this kind of infection. Only three strains of the parasite (Leptospira icterohemorrhagiae, Leptospira canicola, and Leptospira pomona) have been identified here. Although cases of Weil's disease (spirochetal jaundice) have been recognized in various parts of the country, there is reason to believe that the incidence of leptospiral infection is probably much higher than is appreciated, particularly with respect to the less spectacular clinical patterns. In a previous article we reported briefly the observation of two cases of leptospiral meningitis in Atlanta, together with