. The natural history of plants, their forms, growth, reproduction, and distribution;. Botany. 698 THE STTBDIVISIONS OF THE VEGETABLE KINGDOM. AntherocerotaceoB.—The oophyte has the form of a little lobed disc, in depres- sions of the surface of which the antheridia and archegonia are sunk. The sporo- gonium is long and cylindrical, and is,invested in a circular sheath at its base. The spore-layer has the form of a hollow cylinder, leaving a sterile, central strand of tissue (the columella). Elaters are present amongst the spores, and serve as nutritive tissue for them rather than as instrumen
. The natural history of plants, their forms, growth, reproduction, and distribution;. Botany. 698 THE STTBDIVISIONS OF THE VEGETABLE KINGDOM. AntherocerotaceoB.—The oophyte has the form of a little lobed disc, in depres- sions of the surface of which the antheridia and archegonia are sunk. The sporo- gonium is long and cylindrical, and is,invested in a circular sheath at its base. The spore-layer has the form of a hollow cylinder, leaving a sterile, central strand of tissue (the columella). Elaters are present amongst the spores, and serve as nutritive tissue for them rather than as instruments of dispersal. In this group. Fig. 896.—Jungermanniaoese. 1 FruUania dilatafa growing on the bark of an Acer. 2 A small portion of this plant enlarged; it shows the stalked spore- capsule burst into four valves; attached to the valves are the elaters. s A shoot of the same FruUania seen from the under side; at the base of each leaf is a little pitcher containing a Rotifer. The little toothed scales lying on the stem are the amphigastria. * A single pitcher and its contained Rotifer. 6 The Rotifer (^Callidina synibiotica) removed from the pitcher, inat. size; 2x20; 8x26; 4x30; ^xlOO. —alone amongst the Liverworts — stomates occur upon the spore-capsule. It dehisces into two valves. There are 103 species. JungermanniaceoB.—Include both thalloid forms, in which the oophyte genera- tion has a general resemblance to that of a Marchantia, and creeping leafy forms (c/. fig. 396 ^); the latter are by far the more numerous. The sporogonium in both cases consists of a long-stalked capsule which splits into four valves (fig. 396^). Elaters are present, often attached to the capsule-wall. The JungermanniacesB grow for the most part on damp earth, stones, and bark of trees. The thalloid forms include the very common Pellia—like a Marchantia^ with. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - colora
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectbotany, bookyear1895
