A 41-year-old woman was first seen at 5 p. m. on July 29, 1959, about 28 hours after ingestion of four or five slices of odd-tasting prepared beets. Earlier in the day she had noted difficulty in reading the newspaper and had had some diplopia. Her husband and daughter, who had also eaten the beets, had vomiting and loose bowel movements during the day, in addition to the visual symptoms. They had difficulty in forming words, and their legs felt like wooden sticks. On examination, the woman's blood pressure was 128/64 mm. Hg, body temperature 98.2 F (36.8 C), pulse rate 72 per minute, and respiration rate 20 per minute. Findings of laboratory studies, ordered at the time of admission, were as follows: hematocrit, 40% volume of cells; hemoglobin level, 12.3 Gm. per 100 cc.; white blood cell count, 6,900 per cubic millimeter, with a differential of 67% segmented and