post-endothelial tissue is known to occur, as in cases of congenital anterior synechiae and of imperfect differentiation of the angle. In these cases, however, the abnormally placed tissue usually resembled rather fluffy iris stroma and did not look like a hyaline reduplication of Descemet's membrane. In conclusion one can only say that the condition is congenital and that it is in all probability due to an abnormality of the postendothelial tissue occurring at and after the 12 mm. stage. The initial cause of the aberration and also the reason for its assumption of the peculiar appearance described must remain obscure, although the possibility of foetal inflammation acting as the initial cause must be admitted.