Text-book of ophthalmology . is therefore designated as the retinal layer (pars retinalis iridissive pars iridica retinae), in contradistinction to the anterior layers, which,as they belong to the uvea, are comprised under the name of pars uvealisiridis (Schwalbe). The retinal pigment layer is composed of two strata of cells, the recognition ofwhich, however, is rendered very difficult by their profuse pigmentation. It is onlyin the embryo (occasionally also in the newborn infant) and in the albinotic eye thatthe two strata can be clearly distinguished from each other without some special prep
Text-book of ophthalmology . is therefore designated as the retinal layer (pars retinalis iridissive pars iridica retinae), in contradistinction to the anterior layers, which,as they belong to the uvea, are comprised under the name of pars uvealisiridis (Schwalbe). The retinal pigment layer is composed of two strata of cells, the recognition ofwhich, however, is rendered very difficult by their profuse pigmentation. It is onlyin the embryo (occasionally also in the newborn infant) and in the albinotic eye thatthe two strata can be clearly distinguished from each other without some special prep-aration. In other cases we must first decolorize the pigment cells artificially by somebleaching process (Fig. 143). We then can distinguish the two strata from each otherand then also establish the fact that they are the continuation of the two layers ofthe secondary ocular vesicle upon the posterior surface of the iris. The anterior stratumof pigment arises from the pigment epithelium of the retina. From the anterior por-. Fio. 143.—Posterior Layers of the Iris. Meridional Section through the Iris op an Adult,Decolorized by Ficks Method. Magnified 300 X the posterior layers of the stroma of the iris, s, with its branched cells, succeeds the dilatatoror the posterior limiting membrane, m, whose posterior surface is lined by the protoplasm and theoblong nuclei of the anterior stratum v, of the retinal pigment layer. In this stratum the boundariesof the individual cells cannot be recognized. The posterior stratum, h, of the retinal pigment layer,consists of elevated cylindrical cells with round nuclei. The cells are of different heights, and are sogrouped that their posterior surface in section forms a series of rounded eminences such as also are tobe found on a smaller scale in the iris shown in Fig. 142. These eminences represent the cross sectionof the dark brown, annular projections, running concentrically with the pupil, which the iris presentson its posterior surfa
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