Identifier: morphologicalstu00camp (find matches)
Title: A morphological study of some members of the genus Pallavicinia
Year: 1914 (1910s)
Authors: Campbell, Douglas Houghton, 1859-1953 Williams, Florence
Subjects: Pallavicinia
Publisher: Stanford University, Cal., The University
Contributing Library: Smithsonian Institution Libraries
Digitizing Sponsor: Biodiversity Heritage Library

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s haustorial organ of the same character as that ob-served in various Jungermanniales, both acrogynous forms like Junger-mannia bicuspidata and anacrogynous types like Aneura. (See Leitgeb(1), Clapp (1).) Material was wanting for the next stages of development, but tojudge from such stages as those shown in Fig. 16, C-E, the first divisionin the terminal cell of the embryo is vertical, and this is followed later bya series of transverse divisions. There is, however, a certain degree ofirregularity in the divisions, as there is considerable variation in the ar-rangement of the cells in different embryos. The upper part of the embryo rapidly elongates, and forms a nearlycylindrical body, the apex of which is slightly enlarged, and marks the 32 GENUS PALLAVICINIA beginning of the capsule, or sporogenous region. It was not possible todetermine the relation of the three regions of the young sporophyte, i. e.,capsule, seta, and foot, to the early divisions in the terminal cell of theembryo.
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Fig. 18. Pallavicinia Zoilingeri. A. Upper part of a young sporophyte, x 300. B. Upper part of an older sporophyte, showing the sporogenous tissue; x about 60. C. Portion of B, more highly magnified. In P. decipiens the young embryo is much shorter than in eitherP. Zollingeri or P. radiculosa, and more nearly resembles that of Morkia,although more elongated than in the latter. Like Morkia, also, the sus-pensor is much less conspicuous than in either P. Zollingeri or P. radicu-losa. The first periclinial walls in the terminal portion of the embryoprobably determine the separation of the sporogenous tissue from thewall of the capsule (Fig. 16, E). The foot is much less clearly markedthan in Morkia, but is more evident in P. Zollingeri than it is in P. radicu-losa; nor is the delimitation of the capsule and seta as definite as in eitherP. decipiens or Morkia. Of the three species examined, P. Zollingeri most nearly resembles METHODS 33 Morkia in the character of the foot, which is somewh

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