232 Mr. Brown on the Female Flower and Fruit of Rafflesia Arnold}, 



I may hereafter have an opportunity of entering fully into the question 

 whether Raffiesiacew and Balanophorece form merely different orders of the 



ture, and very different from that of all the other genera belonging to Loranthacece, to which this genus 

 has been referred, and to which, though it does not absolutely belong, it is nearly related. Even this 

 peculiar structure of the stems of Myzodendron admits of considerable modifications in the different 

 species of the genus, which is strikingly exemplified in comparing the loose vascular tissue with large 

 and singularly-constructed medullary rays of M. brachystachyum and quadriflorum with the more minute 

 vessels and extremely narrow rays of M. punctnlatum. 



I may also notice that in Tillandsia usneoides, as well as in the nearly-related species of that genus, 

 the capillary stems are destitute even of spiral vessels, though in Bromeliacece generally the ordinary 

 vascular system is found. 



Whatever may be the state of vessels in the fully-developed parasites belonging to Rafflesiaceee, it ap- 

 pears to me that at least Rafflesia in its very early stages is entirely cellular, and that this continues to be 

 the case not only until that mutual adaptation of parasite and stock which enables the former to complete 

 its development has taken place, but until the first indications of its future structure have become per- 

 ceptible. It may also be remarked, that even after the formation of vessels in the parasite is obvious, 

 the direct union between Rafflesia and the Vitis continues to be chiefly if not entirely cellular, the con- 

 nexion consisting in a slight mutual penetration or indentation of the two substances, whose cells are 

 easily distinguishable. 



I may here advert to one of the most difficult points in the ceconomy of Rafflesiaceee, namely, by 

 what means their minute embryos, which are at the same time of an extremely loose texture, are 

 enabled to penetrate through the bark of the plants on which they vegetate, so as to account for such 

 appearances as those exhibited in the nascent Rafflesia Arnoldi represented in Tab. XXVI. A., in which 

 I have been unable to trace any perceptible communication with the surface, and where the parasite 

 seems rather to grow out of than into the stock. 



Connected with this point a question may also arise, whether the earliest effort of the seed after its 

 deposition 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. 



This question might not occur in regard to Rafflesia and Brugmansia, in both of which the individual 

 olants are in general sufficiently distant on the root of the Vitis to make it probable that each developed 

 parasite is produced from a distinct seed. But in Pilostyles, and even Cytinus, where they are closely 



closely allied, especially through Antidaphne of Pceppig, appears to me to have characters sufficient to 

 distinguish it as, at least, a subordo or tribe (Myzodendrece), namely, the structure of its ovarium, in 

 which it approaches to Santalace*, having three ovula suspended from the apex of a central placenta, 

 only one of which ripens ; the entire absence of floral envelope in the male ; the singular feathery ap- 

 pendages of the female flower and fruit compensating in the dispersion and subsequent adhesion of its 

 seeds, which are destitute of that viscidity existing in those of the parasitic Loranthacece ; and lastly, the 

 embryo being undivided, with its dilated and exserted radicle inclosed in a semitransparent covering, 

 a continuation of the membrane lining the cavity of the albumen in which the embryo is lodged. 



