. Plants and their uses; an introduction to botany . Fig. 320.—Thread-weed {Xemalion multifidian. Thread-weed Family,Helminthocladiaccw). I, branch bearing male gamctaugia (sp), and afemale gametangium with swollen base (c) and slender neck (t). II, afemale branch after fertilization, the neck (0 withered, and the basebeginning to divide for the formation of branches. III-V, later stagesin the formation of branches which finally bear spores. All muchmagnified. (Thuret and Bornet.)—A brownish-red seaweed withbranches 5-20 cm. long, on exposed rocks at low-water mark. NorthAtlantic coast. by for
. Plants and their uses; an introduction to botany . Fig. 320.—Thread-weed {Xemalion multifidian. Thread-weed Family,Helminthocladiaccw). I, branch bearing male gamctaugia (sp), and afemale gametangium with swollen base (c) and slender neck (t). II, afemale branch after fertilization, the neck (0 withered, and the basebeginning to divide for the formation of branches. III-V, later stagesin the formation of branches which finally bear spores. All muchmagnified. (Thuret and Bornet.)—A brownish-red seaweed withbranches 5-20 cm. long, on exposed rocks at low-water mark. NorthAtlantic coast. by formation of the carpospores wnthin the thallus, as shown inFig. 321. reproduction is accomplished verj^ generallythroughout the class by non-motile spores, which are producedusually four in a sporangium. The sporangia may be either at thesurface or embedded witliin the thallus as in Chondrus. The thallus in , as with a large part of the class,exhibits a differentiation of cells similar to that already ^ Carpo-spore < Gr
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1913
