550 Mr. Hassall on the Structure of the Pollen Granule, 



others. See fig. 44. This form seems to result from the union of 

 four of the preceding granules. 



Salpiglossis atropurpurea. 



Gesneraceje. 

 Gloxinia speciosa. Gesnera bulbosa. 



Trevirania coccinea. G. Douglassii. 



ACANTHACEJS. 



Pollen granules cylindrical, not diminishing in size towards either 

 extremity ; ends rounded ; extine perforated apparently with minute 

 apertures. Pollen tubes three, issuing through longitudinal fissures. 

 PI. XIV. fig. 45. 



Justicia variabilis. 

 Pollen grain of an oval form, with but one longitudinal fissure and 

 one pollen tube issuing from the smaller end. The comparison of 

 pollen of this form to a Pholas is not inapt. See fig. 46. 

 Acanthus spinosa. 

 Circular, surface presenting a lobulated appearance, the lobes being 

 separated by lines which cross each other, in some of which fissures 

 are placed for the escape of the pollen tubes. See fig. 47. 

 Thunbergia alata. 

 Pollen grain in its dry state cylindrical ; when moist nearly cir- 

 cular, reticulated, reticulation apparently formed in the same way as 

 that of Cobcea scandens. See fig. 48. 



Eranthemum pulchellum. 



BiGxVONIACEJi;. 



Pollen grain cylindrical, three-lobed. 



Eccremocarpus scaber. Bignonia radicans. 



DUCAMENTOS^. 



Myoporace^. 

 Pollen grain cylindrical, three-lobed. 



Myoporum parviflorum. 



Verbenace^. 

 Pollen grain cylindrical, three-lobed. 



Lantana Sellowii. Clerodendrum florabundum. 



Verbena teucroides. Aloysia citriodora. 



Pollen grain of considerable size, triangular, sides of triangle much 

 incurved, furnished with three membranes, the second of which, or 

 exintine, protrudes through the apertures in the extine, forming 

 at each angle of the figure a prominent rounded projection ; a pollen 

 tube of large dimensions issues from each angle. Extine covered 

 with a number of oval-looking bodies. See fig. 49, which exhibits 

 an abnormal form of the pollen granule of Stachytarpheta mutabilis. 

 Stachytarpheta mutabilis. S. Jamaicensis. 



Labiate or Limariace^. 

 Pollen grain cylindrical, three-lobed. 



Teucrium lucidura. T. pyrenaicum. 



