Mr. Hassall on the Structure of the Pollen Granule. 549 



taken from the stigma spherical, from the imbibition of the abundant 

 secretion furnished by that organ. 



Allamanda cathartica. Vinca herbacea. 



Plumeria conspicua. V. rosea. 



Pollen grain spherical when removed from the stigma and fur- 

 nished with four pollen tubes. PI. XIV. fig. 37. 



Nerium Oleander. 



Gentianace^e. 

 Pollen grain cylindrical, three -lobed. 

 Chironia pubescens. Gentianella cruciata, 



Gentiana asclepiadea. 



SoLANACEiE. 



PI. XIV. fig 



Cylindrical, three-lobed. 

 Hyoscyamus niger. 

 H. pallidus. 

 Petunia atropurpurea. 

 P. violacea. 

 P. rosea. 



Lycopersicum erythrocarpum. 

 Datura Stramonium. 



42. 



38, 39, 40, 41 

 Saracha viscosa. 

 Atropa belladonna. 

 Physalis oxalidifolia. 

 P. Alkekengi. 

 Solanum Dulcamara. 

 S. stramonifolium. 

 Capsicum annuum. 



Many of the granules of the two following species are four-lobed, 

 Nicotiana Tabacum. Solanum tuberosum. 



>CItOPHULARIACE.E. 



Pollen grain cylindrical, three-lobed. 

 Buddleia globosa. 

 Veronica longifolia. 

 V. Chamsedrys. 

 Gratiola officinalis. 

 Mimulus guttatus. 

 M. elatus. 

 M. roseus. 

 Digitalis purpurea. 

 Russelia juncea. 

 Penstemon pubescens. 

 P. pentaphyllum. 

 P. speciosum. 

 P. diffusum. 

 Anthocercis albicans. 

 Franciscea Hopeana. 



See fig.43. 

 Franciscea mutabilis. 

 Schizanthus pinnatus. 

 Rhodochiton volubile. 

 Antirrhinum majus. 

 Linaria pilosa. 

 L. genistoides. 

 L. purpurea. 

 L. dalmatica. 

 Scrophularia nodosa. 

 S. aquatica. 

 Alonsoa urticifolia. 

 Calceolaria elegans. 

 Celsia Cretica. 

 Verbascum Phoeniceum. 

 V. Thapsum. 



Exception. 



Pollen granules united in fours, three upon the same plane and 

 one resting on these ; the three lower granules appear to emit but 

 two pollen tubes, the third being most probably suppressed by the 

 union of the granules, while the upper one sends off three tubes ; 

 those in the lower grains issue opposite to each other near the point 

 of juncture of the granules, while those of the upper one are given 

 off at equal distances round the circumference, alternating with the 



