These studies are designed to clarify the immunologic mechanisms that can lead to ocular (and specifically corneal) pathology. The experimental model principally employed involves study of specific rejection of lamellar and penetrating corneal allografts in the rabbit. It is hoped that these studies will clarify the mechanism of lymphoid cell destruction of allogeneic corneal endothelial target cells, as well as to provide additional information on the pathogenesis of this and other forms of allergic interstitial keratitis.