Quain's elements of anatomy . Fig. 47.—Section of the stratified epithelium covering the front of the CORNEA OF THE EYE. HiGHLY MAGNIFIED. (E. A. S.) c, lowermost columnar cells; p, ijolygonal cells above these ; /, flattened cells nearthe surface. The intercellular channels, bridged by minute processes of the cell, are wellseen. The lower part of the section on the right is somewhat broken. a rule the cells of the deepest or attached layer are columnar (fig. 47, c),and the superficial cells are flattened scales (fig. 4:1, fl) which nmy be ofconsiderable size, but which do not, like the cells
Quain's elements of anatomy . Fig. 47.—Section of the stratified epithelium covering the front of the CORNEA OF THE EYE. HiGHLY MAGNIFIED. (E. A. S.) c, lowermost columnar cells; p, ijolygonal cells above these ; /, flattened cells nearthe surface. The intercellular channels, bridged by minute processes of the cell, are wellseen. The lower part of the section on the right is somewhat broken. a rule the cells of the deepest or attached layer are columnar (fig. 47, c),and the superficial cells are flattened scales (fig. 4:1, fl) which nmy be ofconsiderable size, but which do not, like the cells of pavement or simjDle scaly epithelium, fit together by theiredges, but, on the contrary, overlap oneanother (fig. 48). The cells of the Fig. Fig. 48.—Epithelium-scales from the inside OF THE MOUTH J MAGNIFIED 260 DIAMETERS (Henle). layers immediately external to thecolumnar layer are rounded in shape,or at least only so far modified asto enable them to fit to the columnar cefls and to one another (, p) ; but as we trace the strata towards the surface, we find thecomponent cells becoming more flattened and larger, whilst at the sametime undergoing a change in their chemical constitution, so that at firstthe external part, and afterwards the whole of the protoplasm of thecell, is converted into horny substance, even the nucleus being at lastinvolved. The deeper protoplasmic cells of a stratified epithelium are continuallymultiplying by cell-division, and, as the new cells which are thus pro-duced in the deeper parts increase in size, they compress and push out-wards those previously formed. In this way cells which were at firstdeeply seated, become gradually shifted towards the surface, undergoingmeanwhile the chemic
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