Woods and Wahlen1-2 in 1959 proposed Histoplasma capsulatum as the probable etiologic agent for ophthalmoscopically similar macular lesions in man. This report prompted the following experimental study. Pigeons were selected for this purpose, since they are readily available and since birds are the first subprimate species to possess a fovea.3,4 Although Histoplasma capsulatum has been repeatedly cultured from the soil in and around chicken coops and pigeon roosts,5-7 and definite epidemics of human disease have resulted in workers in such areas,8,9 previous attempts to produce progressive lesions with this organism in birds have been unsuccessful.10,11 This is a report of the first successful progressive infections with H. capsulatum induced in birds and shows the course of untreated primary avian ocular histoplasmosis. Material and Methods The common domestic pigeon and a few homing pigeons (Columba livia) were used. Dilutions of H. capsulatum were prepared for injection