Text-book of botany, morphological and physiological . of these somewhat complicated processes see Pringsheim, Jahrbuch furwissen. Bot. 1; Hofmeister, Handbuch der phys. Bot. I. p. 154, and Niigeli und Schwendener,Mikroskop, II. p. 549. THE CELL-WALL. 33 the tissue (annular vessels in the fibro-vascular bundle of Equiseta, Zta Mais, &c.); but thethickenings formed like spiral bands may often be drawn out to considerable length asisolated fibres (very striking examples of these so-called untwisting spiral vessels are foundin the rachis of the inflorescence of Richius communis and in the leaves
Text-book of botany, morphological and physiological . of these somewhat complicated processes see Pringsheim, Jahrbuch furwissen. Bot. 1; Hofmeister, Handbuch der phys. Bot. I. p. 154, and Niigeli und Schwendener,Mikroskop, II. p. 549. THE CELL-WALL. 33 the tissue (annular vessels in the fibro-vascular bundle of Equiseta, Zta Mais, &c.); but thethickenings formed like spiral bands may often be drawn out to considerable length asisolated fibres (very striking examples of these so-called untwisting spiral vessels are foundin the rachis of the inflorescence of Richius communis and in the leaves of Agapanthus).If the thickening of the cell-wall takes place over more extended portions of the surface,and if only smaller portions remain thin, these latter appear as pits of very variousoutline, either roundish or like fissures, or, when the thickening of the cell-wall isvery considerable, as channels, which perforate them. These kinds of thickening mostfrequently project on the inner side of the cell-wall; the channels therefore run from the. Fir,. iS.—Cell-forms of Marchaiilia foly-7norpha with tliickeninjTS projecting inwards;A an elater (Schleuderzelle) (one-half) from thesporangium, with two spiral bands ; A a portionmore strongly magnified ; B a parenchyma-cellfrom the centre of the thallus, with thickeningsprojecting inwards in a reticulate manner; C athin root-hair with thickenings projecting inwards,these are arranged on a spiral constriction ofthe cell-wall; at Z> a thicker root-hair, with pro-jections thicker and branched, and spiral ar-rangement still clearer. L- rhl i
Size: 1234px × 2024px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1870, booksubjectbotany, bookyear1875
