literature of tumors of the eye covers many hundreds of cases and thousands on thousands of printed pages. delegation of this subject to me by the officers of the Section on Ophthalmology of the American Medical Association appalled me by its vastness, and I, therefore, selected only one portion, which is, perhaps, its most important phase, that of the differential diagnosis and prognosis of tumors of the uveal tract, dealing with this subject mostly from the clinical standpoint. A companion essay on The Microscopic Findings of the So-called Leucosarcoma is offered to the Section by Dr. E. V. L. Brown, of Chicago. most important monograph on this subject is by Felix LaGrange, 1 which comprises two massive volumes, 1,739 pages in all, and to this work I am indebted for much of the information which follows: From the richness of its circulation, its complex structure, its superficial