. A treatise on diseases of the eye . clera and microphthalmosocc-iir. The groove in the optic stem gradually closes by approxi-mation of its margins, including the mesoderm and the blood-vessels,the forming the iirtcria and vena retin;e centralis. Development of the Lens.—By an increase in the cells of the ecto-derm forming the walls of the lens pit the pit deepens, its bordersaj)proach and coalesce, converting it into a sac, the lens vesicle. Thelens vesicle .soon becomes detached from the outer layer of ectoderm andlifs in the oj)ening of the ojitic cup. At this stage the walls of t
. A treatise on diseases of the eye . clera and microphthalmosocc-iir. The groove in the optic stem gradually closes by approxi-mation of its margins, including the mesoderm and the blood-vessels,the forming the iirtcria and vena retin;e centralis. Development of the Lens.—By an increase in the cells of the ecto-derm forming the walls of the lens pit the pit deepens, its bordersaj)proach and coalesce, converting it into a sac, the lens vesicle. Thelens vesicle .soon becomes detached from the outer layer of ectoderm andlifs in the oj)ening of the ojitic cup. At this stage the walls of the lensvesicle are of almost uniform thickness, and consist of two or three layersof elongated epithelial cells, which are placed with their long axesperpendicular to the surface of the vesicle and are interlaced. The outerc-ells lie on a delicate homogeneous membrane, the rudiment of thelens cajjsule. fhe cells of the inner or posterior wall of the lens cap-sule become elongated and rapidly form primitive lens fibers; they PLATE I.
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecteyediseases, bookyear
