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264
Palisota Barteri Hook fil. and
Rheo discolor L.
differ from what is surely the rule in the Commelinaceae.
Only regarding Palisota it deserves to be. especially mentioned
that pollen grains of a very big size were often found. In size
those pollen cells exceeded the ripe normal tetrads. Further they
constantly showed a scanty, highly vacuolated plasma content with
a hypertrophied nucleus within. The origin of the giant pollen
grains could not be ascertained in the material at hand.
Flagellariaceae.
The , only member of this family, available for investigation of
the pollen formation was
Flagellaria indica L.
Here the irregularly formed, mostly rectangular pollen mother cells
are very small and possess only a rather thin membrane. In the
heterotypic spindle a cellplate is organised. The homotypic di-
vision generally follows the heterolypic one very rapidly; some-
times the first partition wall has not been completely established
before the homotypic plates are already visible. Frequently the
homotypic spindles are arranged at right angles to the hetero-
typic wall, thus giving rise to a »row of four», in other instances
the orientation of the spindles is such that the four cells are all
lying in one plane.
Eriocaulaceae.
Successiy bipartition has in this family been recorded for
Eriocaulon truncatum
and another not yet determined species of Eriocaulon.
Both those forms show an identic development and agree to a
remarkable degree with Flagellaria and Stemona. They have the
same minute irregular pollen mother cells and tetrads; the processus
of cytokinesis is also practically the same.
Gramineae.
In accordance with the results of other investigators on grasses,
successiy bipartition occurs in
Paspalum conjugatum Berg,
investigated by the author.
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