https://i0.wp.com/c8.alamy.com/comp/PG060R/the-structure-and-development-of-mosses-and-ferns-archegoniatae-plant-morphology-mosses-ferns-26-mosses-and-ferns-chap-in-riccia-glauca-as-well-as-other-species-the-uppermost-cell-of-each-row-often-enlarges-very-much-and-with-its-fellows-in-the-other-rows-constitutes-the-epidermis-according-to-leitgebs-researches-this-epidermal-cell-is-formed-by-the-first-division-in-the-outer-cell-of-the-segment-and-either-undergoes-no-further-division-or-by-dividing-once-by-a-transverse-wall-forms-a-two-layered-epidermis-r-bischomi-on-the-ventral-side-the-odter-cells-of-the-segments-pro-PG060R.jpg?w=1000