Sclera nitrogenous sugar, hexosamine) to embed the fibrils. The cornea, unlike the sclera, has five layers. The middle, thickest layer is also called the stroma. The sclera, like the cornea, contains a basal endothelium, above which there is the lamina fusca, containing a high count of pigment cells. Sometimes, very small gray-blue spots can appear on the sclera, a harmless condition called scleral melanocytosis. Human eyes are somewhat distinctive in the animal kingdom in that the sclera is very plainly visible whenever the eye is open. This is not just due to the white colour of the human sclera, which many
Outer nuclear layer and prolonged from either extremity of each cell is a fine process; the outer process is continuous with a single rod of the layer of rods and cones; the inner ends in the outer plexiform layer in an enlarged extremity, and is imbedded in the tuft into which the outer processes of the rod bipolar cells break up. In its course it presents numerous varicosities. The stem-like cone granules, fewer in number than the rod granules, are placed close to the membrana limitans externa, through which they are continuous with the cones of the layer of rods and cones. They