. A Manual of botany : being an introduction to the study of the structure, physiology, and classification of plants . Botany. 738 FOSSIL PLANTS OF THE CAEBONIFEKOUS SYSTEM. that in both Equisetums and Calamites the fibro-vascular bundles are but poorly developed: that the mass of tissue (woody wedges'" of WUliamson) forming the most important part of the stem consists of the small fibro-vascular bundles, with the addition of a large quantity of thickened parenchyma and prosenchyma (sclerenchyma of Met- tenius) : that the sclerenchyma is part of the cortical tissues, and not a portion of
. A Manual of botany : being an introduction to the study of the structure, physiology, and classification of plants . Botany. 738 FOSSIL PLANTS OF THE CAEBONIFEKOUS SYSTEM. that in both Equisetums and Calamites the fibro-vascular bundles are but poorly developed: that the mass of tissue (woody wedges'" of WUliamson) forming the most important part of the stem consists of the small fibro-vascular bundles, with the addition of a large quantity of thickened parenchyma and prosenchyma (sclerenchyma of Met- tenius) : that the sclerenchyma is part of the cortical tissues, and not a portion of the fibro-vascular bundles : that there is no evidence of any growth having taken place in the fibro-vascular bundles com- parable to that observed in Dicotyledons; but that if the stems of Calamites increased in diameter it was by additions to the cortical tissues, and not to those of the fibro-vascular bundles: that the pointed ends of the Calamite stem (indicating that the embryonic parts did not enlarge) lead to the conclusion that circumferential growth did not take place, but that the stem, when it attained its maximum diameter close to the base, remained cylindrical. r ' 4i---==^-=Ji^ gi ., Fig. Kg. 919. In Spitzbergen, in rocks of the Carboniferous epoch, there have been found Calamites radiatus, Lepidodendron Veltheimianum, Sigil- laria distans, Stigmaria ficoides, and ferns apparently the same as those found in the Carboniferous epoch in Europe. Some species, as SigiUaria Malmgreni, S. Canneggianna, and Lepidodendron Wilkii, seem to be peculiar to Bear Island. In the family Calamitacese we have the genera Equisetites and Calamites. Some also place in this family the genera Asterophyllites, Sphenophyllum (fig. 918), Annularia (fig. 919), and Volkmannia. Annularia may be a link between Equisetacese and Ferns, and Sphe- nophyllum a link between Lycopodiacese and Ferns. Williamson Fig. 918.' Sphenophyllum dentatum, one of the dubious forme of the Carboniferous syste
Size: 1692px × 1476px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1870, booksubjectbotany, bookyear1875
