Archivo: EB1911 Plants - examples of cell differentiation (2)

Descripción: Examples of the differentiation of the tissue of plants. J, End of hydroid of the Moss Mnium, showing particularly thin oblique end wall. No pits. K, Optical section of two adjacent leptoids of the Moss Polytrichum juniperinum. The leptoids are living and nucleated. They bulge in the neighbourhood of the very thin cross-wall. Note resemblance to H and R. L, Optical section of cell of parenchyma in the same moss. Embedded in the protoplasm are a number of starch grains. M, Part of elongated stereid of a Moss. Note thick walls and oblique slit-like pits with opposite inclination on the two sides of the cell seen in surface view. N, One side of the end of hydroid (tracheid) of a Pteridophyte (fern), with scalariform pits. O, Optical section of two adjacent leptoids (sieve-tube segments) of Pteridophyte, with sieve plates (s. pl.) on oblique end-wall and side-walls. P, Part of spiral hydroid (tracheid) of Phanerogam (Flowering Plant). Q, Three segments of a “pitted” vessel of Phanerogam. R, Optical section of leptoid (sieve-tube segment) of Phanerogam, with two proteid (companion) cells. s. pl., sieve-plate. S, Optical section of part of thick-walled stereid of Phanerogam, with almost obliterated cavity and narrow slit-like oblique pits. T, Part of vertical section through blade of typical leaf of Phanerogam. u.e., Upper epidermal cells, with (c) cuticle. (p) Assimilating (palisade) cell. sp., Assimilating (spongy) cells with large lacunae. l.e., Lower epidermis, with st., stoma U, Absorbing cell, with process (root-hair) from piliferous layer of root of Phanerogam. V, Endodermal cell of Phanerogam, with suberized central band on radial and transverse walls.
Título: EB1911 Plants - examples of cell differentiation (2)
Créditos: Encyclopædia Britannica (11th ed.), v. 21, 1911, “Plants,” p. 730, fig. 1a.
Autor(a): not specified
Permiso: Public domainPublic domainfalsefalse This image comes from the 13th edition of the Encyclopædia Britannica or earlier. The copyrights for that book have expired in the United States because the book was first published in the US with the publication occurring before January 1, 1927. As such, this image is in the public domain in the United States.
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