558 Mr. Hassall on the Structure of the Pollen Granule. 



SlJRI ANACE^E. 



Pollen granule cylindrical, three-lobed. 



Cneorum tricoccum. 



TROPvEOLEiE. 



Pollen granule cylindrical, three-lobed. 



Tropaeolum peregrinum. Tropaeolum majus. 



Balsaminace>e. 



Pollen granule elongated, quadrilateral, and emitting a pollen 

 tube at each angle. PI. XVII. fig. 112. 



Impatiens noli me tangere. I. glandulifera. I. parviflora. 



GeRANIACEjE. 



Pollen granule very large, somewhat spheroid in its moist condi- 

 tion, emitting three pollen tubes. See fig. 113. 



Geranium sylvaticum. Pelargonium peltatum. 



RuTACEjE. 



Pollen granule cylindrical, three-lobed. 



Correa alba. Ruta graveolens. 



AlSINACE^E. 



Pollen granule spherical ; extine perforated with about ten aper- 

 tures, placed nearly at equal distances from each other. See fig. 1 14. 

 Dianthus barbatus. D. deltoides. Gypsophila elegans. 



Silenace^e. 



Pollen granule same as the preceding. 

 Silene Armeria. Silene vespertina. Saponaria officinalis. 

 S. inflata. Saponaria viscida. 



PoRTULACACE^E. 



Pollen granule cylindrical, three-lobed. See fig. 115. 

 Calandrinia speciosa. C. discolor. 



Malpighiace^e. 



Pollen granule spherical, pollen tubes about sixteen. See fig. 116. 

 Malpighia punicea. 



Celastrace^e. 

 Pollen granule cylindrical, three-lobed. 



Celastrus Pyracanthus. 



Eufhorbiace^e. 

 Pollen granule cylindrical, with three lobes. 



Ricinus communis. 



Rhamnace^e. 



Pollen granule small, triangular, furnished with three membranes. 

 PL XVII. fig. 117. 



Zizyphus Paliurus. 

 Pollen granule cylindrical, three-lobed. 



Ceanothus pallidus. 



