It has long been a well known and uncontested fact that in cases of retinal detachment there is usually a hole or a tear in the retina, which is, moreover, the cause of the continuation of the detachment, closure of the hole usually resulting in a cure. Hence, in determining the origin of a retinal detachment, the question of the origin of holes and tears is of primordial importance. We have tried to form a theory concerning the etiology while awaiting a case in which the tear and detachment could be observed directly.
Recently we were able to observe the development of a horseshoeshaped tear in one patient and to watch the consecutive changes preceding detachment of the retina in another patient. In Mr. W. P. (1931), in a small area at the top of the retina toward the temple, we saw three small oval holes ; they lay