. Physiological botany; I. Outlines of the histology of phænogamous plants. II. Vegetable physiology. Plant physiology; Plant anatomy. III. Cribrose-cells, Sieve-cells, or Sieve-tubes. 279. In the inner bark of stems of rlieotyledons with normal structure certnin long cells of peculiar character are found as- sociated with bast-fibres. They are of tubular or prismatic form, and are characterized by tlie pres- ence of circumscribed panels in the walls, in whicli are numerous fine perforations permitting com- munication between contiguous cells. The panels are known as sieve-plates ; tlie perfor
. Physiological botany; I. Outlines of the histology of phænogamous plants. II. Vegetable physiology. Plant physiology; Plant anatomy. III. Cribrose-cells, Sieve-cells, or Sieve-tubes. 279. In the inner bark of stems of rlieotyledons with normal structure certnin long cells of peculiar character are found as- sociated with bast-fibres. They are of tubular or prismatic form, and are characterized by tlie pres- ence of circumscribed panels in the walls, in whicli are numerous fine perforations permitting com- munication between contiguous cells. The panels are known as sieve-plates ; tlie perforations, as sieve-pores. These cells consti- tute an essential, though by no *'" ™ means always a conspicuous, element of fibro-vascular bundles. Taken collective]3", they may be known as cribriform tissue. By their union end to end they appear like long tubes with the continuity interrupted here and there by cross partitions. These par- titions which separate the individual cells are sometimes nearly horizontal, but more generallj- oblique, as shown in the annexed figures where they mostl}' cut the lateral wall of the cell at a sharp angle. 280. The walls of cribrose-cells are never lignified ; on the contrary, they are Fig. 69. Pinus sylvestris. Face view of radial wall containing two cribrose-plates vrijolly depriveil of callus, "f*. (Janczewski) Fig. 70. Pinus sylvestris. Eadial wall of a young tube, face view. The future cri- brose-plates are composed of callus-cylinders, filling the meslies of a cellulose network. ^Y^. (Janczewski.) Fig 71. Cribrose-cells in A^'itis vinifera: .^4, transverse anastomosis of two cribrose-. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Goodale, George L. (George Lincoln), 1839-1923. New York [etc. ] : American Book Co.
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectplantanatomy, bookyea
