264 



Palisola Bar ter i Hook fil. nnd 



Rheo discolor L. 

 differ from \vhal is surely the riile in Ihe Commelinaceae. 



Only regarding Palisota it deserves lo be especialh' 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 scanly, highly vacuolated plasma content with 

 a hypertrophied nucleus within. The origin of the giant pollen 

 grains coiild not be ascerlained in the material at hand. 



Flagellariaceae. 



The only member of this family, available for invesligation 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 

 Ijång in one plane. 



Eriocaulaceae. 



Successiv bipartition has in this family been recorded for 



Eriocaulon trnncatnm 

 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, 

 successiv bipartition occurs in 



Paspalum conjiigatiim Berg, 

 investigated by the author. 



