The citation of rare cases is of value only so far as it makes for more exact diagnosis, which in turn tends to make the treatment of disease less empirical. The purpose of this paper is to report a case in which there were a blood picture of monocytic leukemia and pathologic involvement of the reticulo-endothelial system. For this clinical picture the title of monocytic chloroma is suggested. A brief review of the literature on chloroma, monocytic leukemia and the reticulo-endothelial system is also presented. REPORT OF CASES History.—F. C., a white American laborer 55 years of age, was brought to the Eye Clinic of the University Hospital on Nov. 26, 1934. He complained of protrusion of the left eye associated with swelling of the lids, diminution of visual acuity, a feeling of fatigue in both eyes and a bulging red mass at the inner angle of the left