named W \ PILES] \. 211 



A satisfactory determination of this point, while n would cer- 

 tainly assist in explaining the nature of the other parts of the < « 

 lumn, might also in some degree lead to correct notions of the 

 affinities of the genus ; and the question is perhaps sufficient!; 

 interesting, even independent of these results. 



In this inquiry, it is necessary in the first place to take a ge- 

 neral view of the principal forms of Anthem- in phanogamous 

 plants ; all of which, however different they may appear, I con- 

 sider as modifications of one common structure. 



In this assumed regular structure or type of Anthcra, 1 sup- 

 pose it to consist of two parallel folliculi or tkeca . fixed by their 

 whole length to the margins of a compressed filament : each thee a 

 being originally filled with a pulpy substance, on the surface or 

 in the cells of which the pollen is produced : and having ils ca- 

 vity divided longitudinally into two equal cells, the subdivision 

 being indicated externally by a depression or furrow, which is 

 also the line of dehiscence*. The 



* A certain degree of resemblance between this supposed regular state of Anthera, 

 and that which in a former essay (on Composite, Linn. Soc. Transact, xii. p. 89.) I 

 have considered as the type of Pistillum in phasnogamous plant-, will probably be ad- 

 mitted ,• and both structures have, as it appears to me, an evident relation to the Lea/', 

 from whose modifications all the parts of the flower seem to be formed. 



This hypothesis of the formation of the Flower may be considered as having origi- 

 nated with Linnaeus in his Prolepsis Plantarum, though he has not very clearly stated 

 it, and has also connected it with other speculations, which have since been generally 

 abandoned. It is, however, more distinctly proposed by Professor Link (in Philos. Bot. 

 Prodr. p. 141), and very recently has been again brought forward, with some modifica- 

 tions, by AC* Aubert du Petit Thouars. 



In adopting the hypothesis as stated by Professor Link, I shall, without entering 

 at present into its explanation or defence, offer two observations in illustration of it, 

 founded on considerations that have not been before adverted to. 



My first observation is, that the principal point in which the anthera? and anuria 

 agree, consists in their essential parts, namely, the pollen and ovula, being produced 

 on the margins of the modified leaf. 



2 E <2 In 



