The first report of a dermatophyte growing saprophytically in nature was that of Szathmary (11) in 1936. He isolated Trichophyton terrestre primum (T. gypseum) from the mud of watercourses in the park of the University of Peco. One year later Muende et al. (10) found a colony of Trochophyton growing on horse dung. Since then Micro? sporum gypseum has been recovered from soil by Gorden et al. (7), Gordon (6), Ajello (1, 2), Durie et al. (4), Fuentes et al. (5), Lurie et al. (8) and Mandels et al. (9). In 1954 Ajello et al. (3) isolated T. mentagrophytes and T. rubrum from shoes which had been stored for 1 to 4 weeks and Epidermophyton floccosum from shoes recently worn by a sufferer from tinea pedis. In 1955 Lurie et al. (8), while investigating the cause of Cave Disease, isolated Trichophyton mentagrophytes from the soil of caves. We believe that the present report is the first record of the isolation of dermatophytes from the atmosphere. One of the two caves from the soil of which T. mentagrophytes was isolated is Johnson's Pothole. This cave is completely uninhabited ex? cept for occasional visits by spelaeologists. A total of 42 animals, including monkeys, rabbits, guinea pigs, rats and mice, was taken into the cave to a depth of about 90 feet where they were left for about 5 hours, during which time a heavy dust was raised by the activity of the spelaeologists. The animals were then brought back to the laboratory where they were kept under observation. The rectal temperature of the larger animals was taken daily. Some of the animals were killed after 6 days and further batches every 2 or 3 days thereafter. Their lungs were removed under sterile conditions; portions were fixed in formalin and sectioned; small fragments were planted on dextrose agar and actidione medium; other portions were macerated by grinding gently with sterile, washed, river sand and suspended in normal saline. After allowing the sand to sediment, the supernatant fluid was planted on the same media and also injected intraperitoneally into 6 mice. Half of these mice were killed after 3 weeks and half after 6 weeks. Their livers and spleens were removed under sterile conditions. Portions were fixed in formalin and sectioned and portions were macerated and planted on dextrose agar and actidione medium.