and on various Plants related to them. 303 



peculiar nature. I have but little doubt that a third variation in manner of 

 parasitism will be found to exist in Thismla. A fourth variation, and one of 

 a very important nature, is said to occur in Pilostyles* (Frostia, Bertero), 

 which is represented as parasitic on the branches of Adesmia nrborea and 

 certain Bauhinia^, and which is admitted without any hesitation by M. End- 

 licher into Raffleslacece. The exception that this plant offers to the almost 

 invariable nature of plants parasitic on stems or their prolongations, might 

 perhaps renew certain doubts as to its true nature ; and in connexion with 

 this I may observ^e, that it was to be remarked of Sapria C'tssi, that when it 

 happened to have germinated upon what appeared to be the true stem, the 

 young plants did not make any considerable advances towards maturity. 



On the other hand, in addition to any argument deducible from Cuscuta, 

 which is, however, scarcely an analogous case, it may be urged that the real 

 part of the plants to which Rqfflesia, Sapria and Brugmansia are attached, 

 requires more positive determination than it has yet received. For M. Blume, 

 who appears to have seen Rajflesia Patma in its natural state, speaks of it (as 

 quoted by Dr. Lindley, Introd. Nat. Syst., ed. 2. p. 391) as taking place on the 

 creeping roots or stems of Cissus scariosa. Curious speculations might be 

 indulged in respecting the parasitism of Rajfflesia, Brugmansia and Sapria. 

 Such might be founded (however slightly) on the difficulty of conceiving by 

 what process a body like a seed can become so internal to the substance of 

 the stock as to become surrounded by a wrapper, through which it subse- 

 quently bursts ; on the fondness of these genera for the genus Fitis ; and on 

 the fact that accidental productions of certain parts of a vegetable may assume 

 a definite form to a considerable extent. 



2. Defective vascularity . — The once-asserted absence of any vascular system 

 lias been so amply contradicted by Mr. Brown, who has re-examined Rafflesia, 

 and extended his inquiries to Hydnora, Cytinus, and all the Balanophorece he 

 had access to, especially Cynomorium and Helosis ; by Dr. Martins, who found 

 vessels in Langsdorjpa ; and by M. Meyer, who also found them in Hydnora, 

 that the question may now be considered to regard their quantity. Indeed 

 M. Endlicher allows Rhizanthecc an imperfect vascular system ; Dr Lindley 

 allows them, in his 'Introduction to the Natural Orders,' a vascular system in 



* Annales des Sciences Naturelles, 2nde s&ie, Juillet 1834, p. 19. 



2 s 2 



