. Plants; a text-book of botany. Botany. 38 PLANT STEUl'TUEES The other group, represented by Fiuus (Fig. 21), pro- duces no asexual spores, but is heterogamous. A single oogonium usually forms eight eggs (Fig. 21, A), which are discharged and float freely in the water (Fig. 21, E). Tlie antheridia (Fig. 21, C) produce numerous minute laterally biciliate sperms, which are discharged (Fig. 21, fr), swim in great numbers about the large eggs (Fig. 21, F, II), and finally one fuses with an egg, and an oospore is formed. As the sperms swarm very actively about the egg and impinge against it they o
. Plants; a text-book of botany. Botany. 38 PLANT STEUl'TUEES The other group, represented by Fiuus (Fig. 21), pro- duces no asexual spores, but is heterogamous. A single oogonium usually forms eight eggs (Fig. 21, A), which are discharged and float freely in the water (Fig. 21, E). Tlie antheridia (Fig. 21, C) produce numerous minute laterally biciliate sperms, which are discharged (Fig. 21, fr), swim in great numbers about the large eggs (Fig. 21, F, II), and finally one fuses with an egg, and an oospore is formed. As the sperms swarm very actively about the egg and impinge against it they often set it rotating. Both an- theridia and oogonia are formed in cavities of the thallus. 4. (Red AJgce) 31. General characters.—On account of their red colora- tion these forms are often called Floridew. They are mostly marine forms, and are anchored by holdfasts of various kinds. They belong to the deepest waters in which Algse grow, and it is probable that the red coloring matter which character- izes them is associated with the depth at which they live. The Eed Algse are also a high- ly specialized line, and will be mentioned very briefly. 32. The plant body. — The Eed Algas, in general, are more deli- cate than the Brown Alga3, or kelps, their graceful forms, delicate texture, and brightly tinted bodies (shades of red, violet, dark purple,. T^iG. S2. A red alga (Gigartina), showing branching habit, and "fruit ;— After 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 Coulter, John Merle, 1851-1928. New York, D. Appleton and company
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