719 



without the intervention of any stem or stalk. To the probability of 

 this, Dr. Brown thus alludes : "Connected with this point a question 

 may also arise, whether the earliest effort of the seed after its deposi- 

 tion in the proper nidus, by whatever means this is effected, may not 

 consist in the formation of a cellular tissue extending laterally 

 under the bark of the stock, and capable of producing the fully 

 developed parasite." {Linn. Trans, xix. 2.32). The genus Pilostylis, 

 expressly quoted by Dr. Brown as offering a mode of development 

 with which he appears to consider both Rafflesia and Brugmansia 

 coincide, Mr. Griffith would exclude altogether from the rhizogens, 

 because of this peculiarity of growth. 



Of the nature of the parasitism of the order Cytinaceae I cannot 

 feel so certain, though from the figures I am inclined to suppose it 

 differs only in degree from that of the Rafilesiacese; the former plants 

 are distinguished from the latter by the scaly stem which rises from 

 what, doubtless, is a kind of mycelium, more highly developed than in 

 the RafHesiacea, and on this stem the reproductive organs are seated, 

 instead of springing directly from the thallus, as in the Rafilesiacese. 

 In this order Dr. Lindley places Mr. Griffith's genus Thisraia, with 

 a mark of doubt ; but this genus appears rather to belong to some 

 exogenous or endogenous order. That it is parasitical, there is hardly 

 a doubt ; though its parasitism would seem to be of a very different 

 nature from that of any of the rhizogens, and its habit indicates a 

 structure of a much higher order. 



The parasitism of the Balanophoraceae again appears to bring them 

 near the lichens in their organs of vegetation; for the thallus from 

 which the clusters of flowers spring bears a very strong resemblance 

 to that of the crustaceous thallogens. But surely, Sparrman's Sar- 

 cophyte can have no business in the same order or class as such plants 

 as Scybalium and Cynomorium. 



On the nature of the organs of vegetation of the plants composing 

 his order of rhizogens. Dr. Lindley has the following remarks : — 



" In Helosis and Langsdorffia the rhizome, which is horizontal 

 and branched, and which at intervals throws up perpendicular flower- 

 ing stalks, is quite analogous to the spawn of fungals. In Cynomo- 

 rium, Scybalium and Balanophora this part is wanting, and in its 

 room the roots of these genera emit roundish deformed tubers collect- 

 ed in a circle upon the roots of other plants, and growing into [query 

 out of] them by some unknown process. Blume says, 'that at the 

 period of germination of Balanophorese there is produced from the 

 roots of the fig on which they grow an intermediate body, of a fleshy 



