THE PURPOSE of this communication is to report the occurrence of two cases of chronic membranous conjunctivitis of unknown origin in white brothers aged 1 and 4 years. These cases are of interest because they have received an extensive etiologic study without a definite bacterial, fungous, or viral agent being established. In both cases extensive treatment with antibiotics and cortisone has been carried out. In addition, in the first case surgical treatment, x-rays, and Streptococcus vaccine were also employed. In neither case has there been any permanent effect upon the membranes. This result has prompted a consideration of the possibility that the disease in these two cases may be a primary tissue aberration related to the general group of ocular pemphigus. A number of similar cases have been reported in the literature from time to time, and an excellent review has been published by Hogan.1 SUMMARY OF CASES Case