r 



named RaFPLESIA, 213 



tinuing, which is also not imfYeqnent ; or accompanied by \a- 

 rious degrees of divergence, as in many genera of Labiate; in 

 their complete confluence while they remain parallel, as in Epa*- 

 cridece, Polygalece, and in some genera of Acanthacea : and Lastly, 

 in the imperfect production or entire suppression of one of the 

 thecae, as in JVe&tringia, Anisomele* and Marantea. 



Increased development may in like manner be confined to 

 the dilatation, elongation, or division of the connecting portion 

 of the filament, of which examples occur in many Sdtaminea . 

 Orckidea and Acanthacea ; it may consist in the elongation of 



I have entered thus slightly at present into the proof of this type, derived from these 

 deviations from regular structure, partly on account of an observation which 1 find in 

 the second edition of the excellent Thtorie Elementaire de la Bot unique of Professor 

 De Candolle, to whom, in 1 8 16, I had shown drawings of most of the instances of mon- 

 strosity now mentioned. To these drawings, and to my deductions from them with regard 

 to the structure of pistillum, I suppose the ingenious author alludes in the passage in 

 question. His views, however, on this subject differ considerably trom mine, which be 

 does not seem to have been aware were already published (Linn. Soc. Trans. I. c). 



My second observation relates to the more important differences between the antherae 

 and ovaria, independent of their essential parts. 



In the Anthera the vascularity, with relation to that of the Leaf, may be said to be di- 

 minished without being otherwise sensibly modified ; the pollen is formed iu a cellular 

 substance apparently destitute of vessels ; and is always produced internally, or under 

 the proper membrane of the secreting organ. 



In the Ovarium, on the other hand, the vascularity, compared with that of the Leaf, 

 is in general rather modified than diminished ; the principal vessels occupying the 

 margins or lines of production, and giving oft' branches towards the axis, whose vascu- 

 larity is frequently reduced. Theovula constantly arise from vascular cords, and, with 

 reference to the supposed original state of the ovarium, are uniformly produced exter- 

 nally ; though by the union of its parts, whether in the simple or compound state, they 

 become always inclosed, and, before fecundation at least, are completely protected from 

 the direct action of light and of the atmosphere. 



In Conifera and Cycadea, however, according to the view I am disposed to take of 

 them (Tuchey's Congo, append, p. 4 34.), this is not entirely the case. But these two 

 families will perhaps be found to differ from all other phoenogamous plants in the more 

 simple structure both of their ovaria and anthera?. 



the 



