230 Mr. Brown on the Female Flower and Fruit of Rafflesia Arnoldi, 



connate with the calyx, and the cellular 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 unques- 

 tionable : if, therefore, its affinity to Hydnora and Rafflesia be admitted, the 

 place of this singular family would be nearly established. 



That Rafflesia, Hydnora and Cytinus do not essentially differ from many of 

 the more perfectly developed Phsenogamous plants in their vascular structure, 

 I have satisfactorily 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 vascular bundles 

 existing in various parts oi Rafflesia, I too hastily assumed the absence of spiral 

 vessels, the expression used evidently implying that I had satisfied myself of 

 their non-existence in the fasciculi or bundles examined ; instead of which I 

 should only have stated that I had not been able to find them. 



The absence of spiral vessels has since been affirmed by Dr. Blume with 

 respect to his Rhizanthece, consisting of Rafflesia and Brvgmamia ; and still 

 more recently by Messrs. Endlicher and Lindley, who, overlooking probably 

 the very positive statement of Dr. von Martins respecting Langsdorjia, have 

 equally denied the existence of spiral vessels in Balanophorece ; and partly, per- 

 haps chiefly, determined by this supposed conformity and peculiarity of struc- 

 ture, have referred Rafflesiacece and Balanophorece to the same natural class. 



* To the third section of Rafflesiacea, Apodanthes and Pilostyles may perhaps be referred. These 

 genera indeed agree with Cytinus in their unilocular ovarium with parietal placentation, in their 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 bracteae. The existence of petals, how- 

 ever, in both, and especially in Apodanthes, will probably be considered as an objection of some weight 

 to their absolute union with Cytinete ; 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 pla- 

 centae are distinct, definite in number, and subdivided into numerous lobes, nearly as in Orchidea. 



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 distin- 

 guished from Pilostyles by the singular insertion of its petals, which also diflfer remarkably in texture 

 from the quadrifid persistent calyx, and by the two bractese 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. 



