. Comparative anatomy of the vegetative organs of the phanerogams and ferns;. Plant anatomy; Ferns. 44 CELLULAR TISSUE. towards the passage of the future slit^ The free edges of the ridges of exit and entrance correspond to the inner and outer edge of the original wall of division. Ihe origin of the respiratory cavity by separation of the sub-epidermal cells precedes the formation of the slit. i i, â ti The mother-cell of the stoma and the products of its division are of equal height with the other epidermal cells, and lie in the same" plane as they. The subsequent various unevenness of h
. Comparative anatomy of the vegetative organs of the phanerogams and ferns;. Plant anatomy; Ferns. 44 CELLULAR TISSUE. towards the passage of the future slit^ The free edges of the ridges of exit and entrance correspond to the inner and outer edge of the original wall of division. Ihe origin of the respiratory cavity by separation of the sub-epidermal cells precedes the formation of the slit. i i, â ti The mother-cell of the stoma and the products of its division are of equal height with the other epidermal cells, and lie in the same" plane as they. The subsequent various unevenness of height and position of epidermaU and subsidiary-cells and ot stomata arises through the growth of the cells subsequently to their division. During growth all cells without exception increase in volume. But the passive tension by the internal tissue, which the epidermis of growing, as also of adult parts undergoes, finally brings about, as Pfitzer has shown in the stomata of the Grasses', a considerable. Fig. 18.âFicus elastica; leaf, transverse section. e~e in eacli case the thickness of the epidermis; A (600) upper side, Ai (350) under side^of the same very young leaf; in A{ a matiire stoma, which remains superficial, and a (tran- sitory) hair; in A two cystoIith-ceUs, recognisable by their thickened outer wall, epidermal cells still undivided. B {600) upper side. Si {390) under side of a somewhat older leaf, epidermal cells dividing. In ^, x is a younger cystolith-cell, andjri an older one which shows the peg-shaped outgrowth ofthewalL 0(390) older leaf, underside; division of now three-layered epidermis is ended, stoma depressed, but the final size and form of the parts is not yet attained. £ upper side of a mature leaf, four-layered epidermis, cystolith-cell (37s). diminution of the absolute height and breadth of the part of the stomatal cells which border the slit. (In Zea Mais the breadth soon after the appearance of the slit amounts to ft, later to , in th
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Keywords: ., bookcentury1800, bookdecad, booksubjectplantanatomy, bookyear1884
