Abstract
Ciliary bodies were obtained from nonanesthetized rabbits slain by decapitation or air embolism as well as from animals after urethan or Diabutal (pentobarbital) anesthesia. Both light and electron microscope studies revealed distinctly different regions. A prominent feature of the cells of the nonpigmented epithelial layer in the anterior region (as defined in this paper) is a vesiclebounded vacuole 0.4 to 1.5 ยต in diameter. Regional variations occurred in different types of small vesicles as well as in the arrangement of the ciliary channels and of the functional structures found between cells. These variations have bearing on questions of how water and ions move across the epithelium. The findings suggest that the anterior epithelium is the more active region in aqueous formation. In the present experiments urethan and Diabutal--directly or indirectly--clearly altered the conditions for formation of aqueous. They provoked an edema in the anterior region of the ciliary processes, in the stroma as well as in two different locations between the epithelial cells. Further examination, with varied methods, would be required in order to establish whether these drugs may or may not be used when the physiology of the rabbit ciliary processes is to be investigated.