Introduction Descriptive morphologic classification of lesions of the anterior eye represents the major classifying system in clinical ophthalmology. Epidemiologic studies have correlated many of these pictures with the presence of infectious agents, noxious stimuli, or presumed allergenic agents.1In some cases histopathologic data has also been accumulated. The studies to be presented were initiated with the hypothesis that many of the described morphologic changes represent successive immunologic stages which can be demonstrated in the rabbit eye by conjunctival application of a nonreplicating heterologous antigen. Materials and Methods Antigen Solution. —BSA (bovine serum albumin, Nutritional Biochemical Company) was used as one immunizing antigen. For conjunctival immunization the antigen was mixed in sodium phosphate buffer (0.1 M, pH 6.8) at a concentration of 150 mg/ml. For systemic immunization the antigen was mixed with complete Freund's adjuvant, 1:1, or prepared as an alum precipitate (100 mg BSA/5.0 ml of 1% aluminum ammonium