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263
Amaryllidaceae.
Very scanty information seems to be had about microsporogene-
sis in Amaryllidaceae. For all till now investigated plants, viz.
Agapanthus
Curculigo recurvata Jack.
Eucharis
Hymenocallis litoralis Salisb. and
Polianthes tuberosa,
successiv bipartition was recorded. Generally a conspicuous cell plate
is laid down in the heterotypic spindle. Growing centrifugally, it
becomes attached to the pollen mother cell membrane where
this membrane forms a slightly projecting equatorial belt. The
second partition is brought about in the same way.
Taccaceae.
In the Lilüflorae simultanous quadripartition has been observed
in the following families: Dioscoreaceae, Iridaceae, Juncaceae and
Liliaceae. To these the family of Taccaceae might now be added
Tacca cristata Jack.
showing the same mode of pollen development.
In several preparations, however, young tetrads were met with
where the four definitive cells were forming a row, indicating thus
the possibility that successiv bipartition had occurred. The tetrads
seen, reminded strongly of those, figured by Levine for Drosera.
Further work is needed to settle this question.
Bromeliaceae.
An investigation of two species of this family,
Crypthanthus acaulis Beer and
Pitcairnia spec.
established the successiv bipartilion for both of them.
Commelinaceae.
Members of this family have repeatedly been investigated; In all
recent publications successiv bipartition seems to have been re-
corded; nor do.
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