Iritis has been studied etiologically from many standpoints, but with the exception of tuberculous and syphilitic iritis, the bacteriologic phase has been rather difficult to approach. When one considers that approximately 40 per cent of all iritis is probably produced by tuberculosis and syphilis, and 60 per cent by a rather heterogeneous group of causes, it becomes obvious that an attempt to classify this large group on a causative basis would be most worth while.
Rosenow1 based some of his ideas of the selectivity of organisms on the intravenous injection of a strain of streptococcus which caused iritis in several instances. Again he produced eye lesions (retinal hemorrhages and infiltration in the ciliary body and the iris) in the nineteenth rabbit after repeated passages of a streptococcus in the eighteen which preceded. Brown, Irons and Nadler2 produced an iritis from the streptococcus recovered from