“…Aspergillomas are thought usually to arise in pre-existing lung cavities or necrotic lesions. Small fungal masses have, however, been demonstrated radiographically in bronchiectatic sacs (Vantrappen, Simons, Woestijne, and Gyselen, 1959), enlargement of aspergillomas and their cavities is well documented (Golberg, 1962;Macartney, 1964), and it is probable that they r*zsult from localized f,ungal growth in any poorly drained lung space (Pesle and Monod, 1954;Segretain, 1962;Villar et al, 1962). I should like to express my gratitude to all who have helped in the preparation of this paper: to Mary P. English for the mycological studies and for her continued encouragement; to Dr. Peter Watts for his assistance in the review of the radiographs; to Dr. J. E. G. Pearson and all the other physicians, surgeons, and general practitioners who have encouraged me to study patients under their care, …”