. Fresh-water biology. Freshwater biology. THE FRESH-WATER ALGAE 167 230 (221) Zoospores with a circle of cilia near the smaller end. Family Oedogoniaceae . 231 _ Plants of branched or unbranched filaments, attached in early stages; chromatophore with irregular, bnear, or net-like perforations and several pyrenoids; membrane often with transverse stnations at one end of a cell. Reproduction by means of zoospores with a circle of ciha near the smaller end and by heterogametes. 231 (232) Plant not branched Oedogonium Link. Plants either monoecious or dioecious; in the latter case the filaments b
. Fresh-water biology. Freshwater biology. THE FRESH-WATER ALGAE 167 230 (221) Zoospores with a circle of cilia near the smaller end. Family Oedogoniaceae . 231 _ Plants of branched or unbranched filaments, attached in early stages; chromatophore with irregular, bnear, or net-like perforations and several pyrenoids; membrane often with transverse stnations at one end of a cell. Reproduction by means of zoospores with a circle of ciha near the smaller end and by heterogametes. 231 (232) Plant not branched Oedogonium Link. Plants either monoecious or dioecious; in the latter case the filaments bearing antheridia may be normal filaments, or tiny filaments of single cells called dwarf males, attached near the oogonia. These originate from special small zoospores called androspores. But one oosphere in an oogonium; the spermatozoid enters through a perforation in the wall or through an opening caused by the throwing off of a cap; antheridia single or many together, each containing one or two antherozoids; oospore brown or red. Asexual reproduction by zoospores borne singly in vegetative cells; they have a crown of cilia about a colorless spot at the anterior end. nium occurs in almost all bodies of water and several species are usually found Fig. 230. Oedogonium crenulato-cosiatum Wittrock, a. oospore. X about 600. b. Oedogonium sp., vege- tative filament, c. division, d. formation of antheridia. 6, c, d. X atout S20. (Original.) Bulbochaete Agardh. Most of the cells bear- ing a long colorless hair, swollen at the base. Reproduction as inOedo- gonium; the dwarf males very frequent. Though not so com- mon as Oedogonium it is found all over the world and sometimes occurs in great quanti- ties, completely cover- ing submerged higher plants with a feathery coating. Small branches which have been detached are also often found among other algae. Fig. 231. Bulbochaete mirabilis Wittrock. a. Plant with oospore. 6. dwarf male on oospore. c. zoospores. X 200. (Original.
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectfreshwa, bookyear1918
