This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1898 Excerpt: ...or urn, filled with loose spores. In the younger stage (fig. 232) the original form is shown. 323. Ferns.--In the ferns the sporangia are usually numerous, stalked, free, and often associated in clusters called sori. They are either produced upon the under surface of the foliage leaves or upon specialized leaves. The ...
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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1898 Excerpt: ...or urn, filled with loose spores. In the younger stage (fig. 232) the original form is shown. 323. Ferns.--In the ferns the sporangia are usually numerous, stalked, free, and often associated in clusters called sori. They are either produced upon the under surface of the foliage leaves or upon specialized leaves. The sori are often arranged in elongated clusters or lines (fig. 233). Each sorus, or a cluster of them, may be protected by a special outgrowth from the cells in its neighborhood, called an indusium (figs. 233, 234). Each sporangium consists of a stalk composed of two or four rows of cells expanding above into a body composed of a single outer layer enclosing the spore-producing cells, and at maturity the spores themselves. The walls of a row of cells more or less completely encircling the body of the sporangium become It must be remembered that the entire plant, consisting of root, stem, and leaves, is the homologue of the capsule and stalk of the mossworts. irregularly thickened (see fig. 401). The strains caused by the unequal absorption and loss of water burst the sporangium at some definite point. This line of dehiscence is often between a pair of large saddle-shaped cells (fig. 401). 324. Sporophylls.--In many of the ferns the leaves which produce sporangia are not different from the foliage Fig. 232.--Diagram of a longitudinal and transverse section of the very young capsule of a true moss (Bryutn). The transverse section is taken along the line AB. a, the mother cells of the spores; c, the columella; is, intercellular space. The constriction at the top marks the limit of the lid. The part below the sporangium is the neck, with nutritive tissues.--Original. Fig. 233.--A leaflet of a fern (Aspidium) seen from the back. Eight sori are shown, ...
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Add this copy of Plant Life to cart. $67.74, good condition, Sold by Bonita rated 4.0 out of 5 stars, ships from Newport Coast, CA, UNITED STATES, published 2016 by Palala Press.
