Text-book of botany, morphological and physiological . t of the wall (Fig. 25, a~e\Fig. 26, C-F). The outline of the thin parts of the wall in the wood of Pinus sylvestrisappears circular on a front view; the rim of the thickening-mass which becomes archedover it grows also in a circular manner, gradually contracting the opening; and thus thefront view of such a pit appears in the form of two concentric circles, the larger of whichrepresents the original dimensions of the thin parLs of the cell-wall (Fig. 25, cb, t), andthe inner one the gradually widening circular rim of the thickening (Fig.
Text-book of botany, morphological and physiological . t of the wall (Fig. 25, a~e\Fig. 26, C-F). The outline of the thin parts of the wall in the wood of Pinus sylvestrisappears circular on a front view; the rim of the thickening-mass which becomes archedover it grows also in a circular manner, gradually contracting the opening; and thus thefront view of such a pit appears in the form of two concentric circles, the larger of whichrepresents the original dimensions of the thin parLs of the cell-wall (Fig. 25, cb, t), andthe inner one the gradually widening circular rim of the thickening (Fig. 25, a-e; Fig. 26,C, D). Now since this process takes place on both sides of a partition-wall of two cells,a lenticular space is enclosed by the two overarchings, which is divided in the middleinto two equal parts by the original thin lamella of the cell-wall (Fig. 26, F, nv); eachhalf of this pit-cavity communicates with the cell-cavity by a circular opening. If thewood-cells lose their protoplasm, and become filled with air and water, this thin mem-.
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectbotany, bookyear1875
