. The elements of botany embracing organography, histology, vegetable physiology, systematic botany and economic botany ... together with a complete glossary of botanical terms. Botany. GYMNOSPERMJE. 163 gives rise, by the formation of a transverse partition, to a cell which is the rudiment of the suspensor. This grows and elongates, and at its lower end the embryo is formed ; the growing point {punotum vegetationis) is opposite to the suspensor; and near it, as lateral' members, are produced the cotyledons. At the end next to and under the sus- pensor, a root, with a few-celled root-cap, is f
. The elements of botany embracing organography, histology, vegetable physiology, systematic botany and economic botany ... together with a complete glossary of botanical terms. Botany. GYMNOSPERMJE. 163 gives rise, by the formation of a transverse partition, to a cell which is the rudiment of the suspensor. This grows and elongates, and at its lower end the embryo is formed ; the growing point {punotum vegetationis) is opposite to the suspensor; and near it, as lateral' members, are produced the cotyledons. At the end next to and under the sus- pensor, a root, with a few-celled root-cap, is formed. The epidermal system consists of one or more layers of epi- dermal cells, frequently much thickened. The xylem portions of their fibro-vascular bundles are compacted into a dense woody cylinder, surrounded by the so-called bark or united phloem portions of the bundles. The generating tissue, or meristem, called cambium, is situated between the phloem (bast) and xy- lem (wood). The mass of xylem is formed of trache'i- des, with thickened walls and bordered pits (Fig. 278). The fundamental tissue consists of parenchyma in the inner portion (pith), which soon loses its vitality; the outer portion (cortex) consists of paren- chyma and sclerenchyma, or collenchyma; in it there is considerable development of cork. The narrow radiating plates of tissue (medullary rays) between the fibro-vascular bundles, are parenchymous in the young, and sclerenchy- mous in the older, stems. The medullary rays have cam- bium, called interfascicular cambium, corresponding in position and function with that of the fibro-vascular bundles. Most Gymnosperms have intercellular canals, filled with turpentine, containing dissolved resin. The class is. divided into three orders, as follows: Cycads {Qjoadeoe), Conifers (^ConifercB), and Joint Firs (GnetacecB). Fig. 27S, Bordered Fits, and diagrams cepresenting their Please note that these images are extracted from scanned page images that
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectbotany, bookyear1883
