The townspeople of little Milan, Mich, watched with satisfaction last week as a work crew cut down the fine old elms and maples around the junior high school parking lot. It was not that they did not love trees. But an odd combination of trees plus bird droppings plus fungus spores plus children had given Milan (rhymes with pylon) a strange epidemic.
During a tuberculosis survey of Milan in 1958, schoolchildren had been given scratches on both arms: one for the tuberculin test, the other for histoplasmosis. This disease, which is like TB in the variety of its effectsranging from an...