In order to determine if ions are actively transported across the corneal epithelium or endothelium, it was decided to excise the cornea and mount it between two chambers so that the composition of the fluid on the two sides could be regulated and analyzed. This arrangement lends itself to the direct measurement of ion fluxes. The critical problem in this method, however, is to keep a dissected cornea functioning normally in vitro. The present work describes a technique of maintaining an excised rabbit cornea alive for up to eight hours while measuring several of its physiologic properties. Materials and Methods Large adult rabbits were killed with intravenous Nembutal (pentobarbital) and the anterior segment of one eye was excised 2 mm. posterior to the limbus within one minute of death. The tissue was held by its scleral lip and immersed in a solution similar in composition to aqueous humor *1where