. Anatomy, descriptive and applied. Anatomy. 1102 THE ORGANS OF SPECIAL SENSE as a rule, arborize in the inner plexiform layer as soon as they enter it; while the processes of the (arger cells ramify close to the inner nuclear layer. 4. The inner plexiform layer is made up of a dense reticulum of minute fibrils, formed by the interlacement of the dendrites of the ganglion cells with those of the cells contained in the next layer, immediately to be described. Within the reticulum formed by these fibrils, a few branched spongioblasts are sometimes embedded. Membrana limitans ijifema Nerve-fibre
. Anatomy, descriptive and applied. Anatomy. 1102 THE ORGANS OF SPECIAL SENSE as a rule, arborize in the inner plexiform layer as soon as they enter it; while the processes of the (arger cells ramify close to the inner nuclear layer. 4. The inner plexiform layer is made up of a dense reticulum of minute fibrils, formed by the interlacement of the dendrites of the ganglion cells with those of the cells contained in the next layer, immediately to be described. Within the reticulum formed by these fibrils, a few branched spongioblasts are sometimes embedded. Membrana limitans ijifema Nerve-fibre layer Ganglionic layer — Inner layer Centrifugal fibre''. Outer nuclear layer Metnbrana limitans externa Layer of rods and cones Diffuse amacrine cell ''Amacrine cells ••Horizontal cell 7 Bod bipolars --•."Cone bipolars '—Pigmented layer Fig. 820.'—Plan of retinal neurones. (After Cajal.) 5. The inaer nuclear or inner granular layer consists of a number of closely packed cells, of which there are three varieties—viz.: (1) A large number of oval cells, which are commonly regarded as bipolar nerve cells, and are much more numerous than either of the other kind. They each consist of a large oval body placed vertically to the surface, and containing a distinct nucleus. The protoplasm is prolonged into two processes; one of these passes inward into the inner plexiform layer, is varicose in appearance, and ends in a terminal ramification, which is often in close proximity to the ganglion cells. The outer process passes outward into the outer plexiform layer, and there breaks up into a number of branches. There are two varieties of these bipolar cells—one in which the outer process arborizes around the knobbed ends of the rod fibres, and the inner around the cells of the ganglionic layer; these are called rod bipolars (Fig. 820); the others are those in which the outer process breaks up in a horizontal ramification, in contact with the end of a cone
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectanatomy, bookyear1913
