. Text-book of botany, morphological and physiological. Botany. CARPOSPORE&. 295 node, the ascending and descending lobes dove-tailing in a prosenchymatous manner. The formation of the cortex takes place so early that the elongating internode is covered by it from the first, the lobes keeping pace with its extension in length and thickness. Each lobe continues to grow, like the stem, by means of an apical cell, which becomes segmented by transverse septa; out of each of the segments cortical internodal and nodal cells are formed by repeated divisions. The latter divide, by successive septa
. Text-book of botany, morphological and physiological. Botany. CARPOSPORE&. 295 node, the ascending and descending lobes dove-tailing in a prosenchymatous manner. The formation of the cortex takes place so early that the elongating internode is covered by it from the first, the lobes keeping pace with its extension in length and thickness. Each lobe continues to grow, like the stem, by means of an apical cell, which becomes segmented by transverse septa; out of each of the segments cortical internodal and nodal cells are formed by repeated divisions. The latter divide, by successive septa, into an inner cell (Fig. 194, D, c), in contact with the internode of the stem, and three outer cells, the middle one (/) of which commonly grows into the form of a spine or ~knob, resembling a leaf. The outer lateral cells (n n) of the cortical node, on the other hand, following the elongation of the internode itself, grow into longer tubes, so that each cortical lobe consists of three parallel rows of cells, the middle row however containing alternately short and long (internodal and nodal) cells. The cortex of the leaves is derived from the leaflets, and its formation is much simpler (Fig. 193, C-E, br). From the basal nodes of Chara other foliar structures also arise, both on the inner and outer side of the base of the leaf (Fig. 192, *S), which Braun calls Stipules; they are always unicellular, and are sometimes very short, sometimes elongated. The nodes are the parts from which all the lateral members of the Characeae originate. The root-like structures or Rhizoids spring from the outer cells of the. FlG. 194.—Development of the cortex of the stem of Chara fragilis; A a very young- internode of the stem with the cortical lobes r still consisting of one cell; R—D its further development; r r signifies in all the figures the cortical lobes that ascend from the lower, r' r' those that descend from the upper leaves; v v the apical cell of each cortical lobe ; £ g its i
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectbotany, bookyear1882
