This article is only available in the PDF format. Download the PDF to view the article, as well as its associated figures and tables. Recognition of the malignant intraocular tumor in the earliest possible stage of its growth is of obvious importance. Diagnosis by ophthalmoscopy is not difficult in the initial stage, before the development of subretinal transudation and retinal detachment. Such an extremely early stage is practically never seen, except in some rare instances in which the tumor is near enough to the macula to create a serious disturbance of the central vision. Once transudation and retinal detachment have occurred, and especially if the tumor is located in the posterior half of the eyeball, diagnosis becomes extremely difficult and is seldom more than presumptive. Consequently, the addition of any pathognomonic feature to the present meager knowledge of this clinical picture, even though it is limited to half of the cases, should be of distinct value. The present paper reports such a feature, viz., detachment of the pars ciliaris retinae, which I observed in