. A handbook of cryptogamic botany. Cryptogams. FLORWE/E 217 posdd, in its vegetative portion, of a single layer of cells ;: in bbtb"cases coloured by phycoerythrin. >. The tetrasporanges â and the male and female organs appear to be homologous to one another, and not to be sharply differentiated. The tetraspores are motile for about forty-eight hours after their escape from the tetrasporange ; by some writers they are described as being endowed with an amoeboid change of form., The trichogyne is quite rudimentary; the pollinoixis attach themselves singly or in niimbers to the fertile
. A handbook of cryptogamic botany. Cryptogams. FLORWE/E 217 posdd, in its vegetative portion, of a single layer of cells ;: in bbtb"cases coloured by phycoerythrin. >. The tetrasporanges â and the male and female organs appear to be homologous to one another, and not to be sharply differentiated. The tetraspores are motile for about forty-eight hours after their escape from the tetrasporange ; by some writers they are described as being endowed with an amoeboid change of form., The trichogyne is quite rudimentary; the pollinoixis attach themselves singly or in niimbers to the fertile portion of the thallus where the â oogonesi or- rudimentary carpogones occur. While in this position they are invested by a thin. cell-wall of â cellulose, and then put out a slender thread of protoplasm which pierces the. cell-wall of the oogone, nearly the whole of the protoplasm of the J)ollinoid passing into this organ. According to Berthold, the contents of the oogone break up, after impregnation, into eight carpospores, the ' octospores ' of Janczewski, which move about, on escaping, in an amoeboid manner^ putting out and withdrawing protoplasmic protru- sion's, then come to rest, and germinate. Porphyra vulgaris (L.), not uncommon on the coasts of Western Europe, is eaten under the name * purple .laver.' Literature. JanczewskiâAnn. Sc Nat., 1873, p. 241. ReinkeâPring-sheim's Jahrb. wiss. Bot., 1878, p. 274, Goebel^Bot. Zeit.,-i878; p. 199. BertholdâMittheii. Zool. Stat. Neapel, 1880 and Fic 195.âTetraspores of fusco-purpic- rea Lyng., showing amceBoid changes of form (magnified). (After Reinke.) Thcjposition of the Ulvace^ is still uncertain. The group includes a small number of generaâ Ulva ((L.), 'Enteromorpha (Lk;), Phycoseris (Ktz.), Prasiola (Ag.), ahd'i]Vr6nQstroma'(Thur.)âof fresh-water or more often of marine or brackish Alg8e;"of'a bright green colour, consisting of a fiat usually ribbon^shaped plate, feomposed of either one (Monostr
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