POLLEN. 9 



The accompanying list of plants shows those of which 

 the pollen has been described. Those marked with an aste- 

 risk I have myself examined and measured. Opposite the 



name of the plant is the size 60 00 ths of an inch, measured 

 by the micrometer. 



The authors who have examined pollen are : 



Purjinke (P.), in Latin. 



Mohl (M.), the first No. in the German edition, the second from 



the French translation in the ' Annales des Sciences Naturelles.' 

 Fritzsche (F.), in German. 



Schacht (Sch.), t Jahrbuch Bot./ Berlin, ii., in German. 

 Nagili (N.), ib. iii. 

 Romanoff (R.), ib. vii. 

 Pollenden (Pol.), Bonn. 

 Leursen (L.), in ( Jahrbuch Bot.,' Berlin, vii. 

 A. Bennett (B.), in the ' Science Review.' 

 Worthington Smith, in the ' Gardeners' Chronicle ' (re-published in 



' Microscopical Journal '). WS. 

 Hassall, in ' Annals of Nat. Hist.' ix. 1834. H. 

 * Micrographical Diet.' (M. D.) 

 Lindley, in ' Introduction to Botany ' (Lind.). 

 Dr. Hooker, in < Sikhim and New Zealand ' (H. f.).. 

 Decaisne, in the ' Bruxelles Academic,' t. xiii. 1837. 



The drawings in these plates are all done to scale j^th of 

 an inch=th or th of life size. 



EXOGENS. 



GKA.HINE.ZE. According to Mohl, they are 'oval, shining, not viscous, 

 finely grained, with a punctiform pore and a narrow halo.' Hassall 

 says, ' granules separate, circular at first, but on the emission of a 

 single pollen tube, with which each grain is furnished, generally be- 

 coming ovoid.' Fritzsche describes the pollen as having a valve to the 

 pore. I find them somewhat prismatic, tapering at both ends, rounded, 

 one smaller than the other, without viscidity. I have been unable 

 to detect the pore. I have examined many species, but find only 

 three which are not prismatic, which are the only species of the 

 Paniceae which I have examined. The pollen flies off so rapidly on 

 the opening of the anthers, that we must secure the pollen as the 

 anthers open. 



Oryzeee. 



*0ryza sativa, 6. 

 Zizania aquatica. H. 



Phalarideee. 



*Zea Mays, 20. 23. M. 

 *0oix Lachryma, 15. 

 *Sorghum saccharatum, 11. M. 

 *Holcus mollis, 7. 

 *Phalaris canariensis, 7. M. 

 picta. P. 1. 12. 



