Text-book of botany, morphological and physiological . the reproductive organs of thePyrenomycetes and Discomycetes, especially from the most recent statements of Janczewski on Asco-bolus furfuraceus {cf. pp. 256 and 261), it may be assumed that the tubular hyphx of the sub-hymeniallayer arise from a yet undiscovered ascogonium or scolecite; and that thus the apothecium ofLichens is the result of a sexual process in a similar manner to the peiithecia of the Pyrenomy-cetes and the fruit-cups of Peziza and Ascobolus. THA LL OPHYTES. the rupture of its apex. This expulsion is probably caused by t
Text-book of botany, morphological and physiological . the reproductive organs of thePyrenomycetes and Discomycetes, especially from the most recent statements of Janczewski on Asco-bolus furfuraceus {cf. pp. 256 and 261), it may be assumed that the tubular hyphx of the sub-hymeniallayer arise from a yet undiscovered ascogonium or scolecite; and that thus the apothecium ofLichens is the result of a sexual process in a similar manner to the peiithecia of the Pyrenomy-cetes and the fruit-cups of Peziza and Ascobolus. THA LL OPHYTES. the rupture of its apex. This expulsion is probably caused by the lateral pressure ofthe swollen paraphyses and the property of swelling possessed by the membrane of theascus itself. The germination of the spores of Lichens takes place by the endospore of eachspore-cell putting out a filament which ramifies and creeps upon the damp substratumon which the spore is placed. The origin of the first gonidia has never been observedafter the dissemination of the spores; but Tulasne sometimes found groups of gonidia at. Fig. 193 —Vertical section of a small portion of the apotheciuin of A^iaptychia ciliaris (x 550); m the medullary layer ofthe thallus; y the hypothecium, together with the sub-hymenial layer; / the paraphyses of the liymenium, tlieir upper endsof a brown colour; among them are the asci in various stages of development; in i are the young spores not yet septate, in2-4 the spores more fully developed ; the protoplasm in which the spores are imbedded is contracted by the drying up of theLichen before the preparation was made. a later period upon the web of hyphae derived from the spores; and even small rudimentsof a thallus were observed; but the genetic connexion of the gonidia with the germinatingfilaments has not been made clear \ The mode of germination of the very large sporesof some genera, Megalospora, Ochrolechia, and Pertusaria, differs from that of all therest. They are simple, not septate, and densely filled with drops of
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectbotany, bookyear1875
