A morphological study of some members of the genus Pallavicinia . Fig. 16. Pallavicinia Zollingeri. A. Two-celled embryo, enclosed in calyptra, x 200. B. An older embryo. C. D. Older embryos, x about 50. E. Upper part of D, more highly magnified. METHODS 31 cells, forming a sort of suspensor, and a terminal portion, consisting offour tiers of cells, from which all of the sporogonium except the sus-pensor is derived (Fig. 16, B). It is probable that two of the three pri-mary cells of the embryo contribute to the suspensor, while all the restof the sporophyte—foot, seta and capsule—is derived fr
A morphological study of some members of the genus Pallavicinia . Fig. 16. Pallavicinia Zollingeri. A. Two-celled embryo, enclosed in calyptra, x 200. B. An older embryo. C. D. Older embryos, x about 50. E. Upper part of D, more highly magnified. METHODS 31 cells, forming a sort of suspensor, and a terminal portion, consisting offour tiers of cells, from which all of the sporogonium except the sus-pensor is derived (Fig. 16, B). It is probable that two of the three pri-mary cells of the embryo contribute to the suspensor, while all the restof the sporophyte—foot, seta and capsule—is derived from the terminalcell. This, however, was not positively Fig. 17. A. Longitudinal section of an embryo of Pallavicinia radiculosa, x 300. B, C. Cross-sections of embryos of about the same age, of P. Levieri. The embryo shown in B was cut somewhat obliquely. The lower suspensor cell does not undergo any further division, butthe upper one may divide two or three times, and there results an ex-tremely conspicuous 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 rapi
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