RAITLESIA ARNOLDI. 411 



the ovula, in the structure of the seed and in that of the 

 antherse. 



The second section, Hydnorece, formed of Hydnora alone, 

 is characterised by its completely adherent ovarium, singu- 

 larly divided stigmata, the peculiar origin and structure of 

 its pendulous placentae, its embryo enclosed and seated in 

 the centre of a dense albumen, and by the arrangement 

 and structure of its antheree. 



In the third section, or Cytinece, the placentee are parietal, 

 the ovarium is connate with the calyx, and the cellular pso 

 undivided embryo forms the whole mass of the seed, or is 

 apparently destitute of albumen.^ 



That this third section is nearly related to Asarince seems 

 to me unquestionable ; if, therefore, its affinity to Hydnora 

 and Bafflesia be admitted, the place of this singular family 

 would be nearly established. 



That Bafflesia, Hydnora and Cytinus do not essentially 

 differ from many of the more perfectly developed Phseno- 

 gamous plants in their vascular structure, I have satisfac- 

 torily ascertained, and there is no sufficient reason to doubt 

 that the same observation may be extended to Brugmansia. 



In my former paper, in treating of the composition of the 



' To tlie third section of Rufflesiacea, Apodanth.es and Pilostyles may perliaps 

 be referred. These genera indeed agree with Cytinus in tlieir unilocular 

 ovarium with parietal placentation, in tlieir cellular undivided embryo forming 

 the whole mass of the seed, and in their adherent or semi-adherent ovarium, 

 whose cavity in Pilostyles extends even below the insertion of the bractese. 

 The existence of petals, however, in both, and especially in Apodanthes, will 

 probably be considered as an objection of some weight to their absolute union 

 with Cytinem; and there is even an important difference in their placentation, 

 the ovula being produced equally over the whole surface of the ovarial cavity, 

 while in Cytinus the placentee are distinct, definite in number, and subdivided 

 into numerous lobes, nearly as in OrchidetB. 



Whether Apodanthes and Pilostyles are to be included in the same genus, as 

 Professor Endlicher (in Gen. p. 76) first conjectured, and as Mr. Gardner has 

 more recently (in Hooker Ic, new ser. vol. iii, tab. 644) endeavoured to prove 

 though not improbable, must, I think, remain somewhat doubtful so long as we 

 are unacquainted with the male flower of Apodanthes. In the mean time this 

 genus may be distinguished from Pilostyles by the singular insertion of its 

 petals, which also differ remarkably in texture from tlie quadrifid persistent 

 calyx, and by the two bracteae of the flower being seated below the origin of an 

 angular ovarial cavity, and which, after the falling off of the parasite, remain 

 attached to the stock. 



