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



eight, issuing from apertures placed upon the equator of the granule. 

 PI. XVI. fig. 80. 



Collomia grandiflora. Collomia coccinea. 



C. rosea. C. lateritia. 



Pollen granule spherical ; extine perforated with about sixteen 

 apertures, which are scattered irregularly over its surface. See 

 fig. 81. 



Gilia achillesefolia. Leptosiphon densiflorus. 



G. tricolor. L. androsaceus. 



G. capitata. Polemonlum cseruleum. 



Pollen granule reticulated, spherical, apertures about fourteen. 

 See fig. 82. 



Phlox acuminata. Phlox Drummondii. 



P. paniculata. P. undulata. 



Pollen granule reticulated ; pollen tubes six or seven, issuing from 

 apertures placed upon the equator of the granule. See fig. 83, 84. 

 Ipomopsis elegans. 



CONVOLVULACE^. 



Pollen granule cylindrical, three-lobed, but quite characteristic. 

 See fig. 85, 86. 



Convolvulus farinosus. Convolvulus pentanthus. 



C. arvensis. C. Scammonia. 



Pollen granule spherical, extine perforated with very large aper- 

 tures. See fig. 87. 



Calystegia arvensis. 

 Extine covered with spines ; in other respects the pollen granule 

 same as that of the preceding species. See fig. 88. 



Ipomaea Sellowii. Ipomsea purpurea. Convolvulus major. 

 I. Horsfallise. I. insignis. 



NoLANACE^. 



Pollen granule cylindrical, three-lobed. See fig. 89. 

 Nolana paradoxa, 



AQUIFOLIACEiE. 



Pollen granule cylindrical, three-lobed. 

 Ilex Aquifolium. 



Ebeneace^. 

 Pollen granule cylindrical, three-lobed. 

 Cargillia australis. 



Pkimulace^. 

 Pollen granule cylindrical, three-lobed. See fig. 90. 

 Anagallis arvensis. Primula vulgaris. 



Primula Sinensis. Cyclamen autumnale. 



Epacridiace^. 

 Pollen granules permanently united in fours, three being placed 

 upon the same plane and one upon these ; three pollen tubes (the 

 emission of which is produced artificially with great difficulty) in 



