Among the most notable studies which have led to a clear understanding of the anatomy of the filtration angle and the aqueous outflow paths in man are those of Leber1and Maggiore2followed later by those of Theobald3and Ascher.4Subsequently Ashton,5by means of neoprene latex casts of the canal of Schlemm and its efferent vessels, confirmed and amplified our knowledge of the anatomy of these channels in a most convincing fashion. Comparative studies in which the rabbit is used have, in the past, helped to elucidate the nature and function of the outflow paths, and today the rabbit continues to be employed to furnish the major part of our knowledge on the physiology of the aqueous outflow mechanism. Unfortunately the anatomy of the outflow paths in the rabbit is still not clear, but it is known that the structures involved are somewhat different