AFFINITIES OF BALANOPHORE^. 3 



suggested doiibtMly by Richard, who however adopted those of "radix," "tuber," and 

 "caulis:" it is the "axis" of Griffith; "rhizome" and "caudex" of Goeppert; "basilar 

 receptacle " of Junghuhn, &c. In mode of origin and development it sufficiently accords 

 with the definition of a rhizome, as visvially employed in descriptive botany. In speaking 

 of the root, I wish always to be understood as referring to that organ of the plant upon 

 which the parasite grows. 



The simplest and at the same time most frequent form assumed by the rhizome of Bala- 

 nophorete, is that of a simple or branched tuber, sessile on the root from which the plant 

 derives its nourishment, and giving off one or more flower-bearing peduncles. In the 

 earliest stage at which I have examined any of the species, the young plant appears as a 

 celliilar mass, nidulating in the bark of the root (but partially exposed), with whose cellular 

 tissue its own is in organic adhesion, though easily distinguishable. It offers at first no 

 trace of a vascular system, nor any distinction of parts ; but before it has reached the 

 cambium layer of the bark, and before its upper extremity has attained any considerable 

 size, an opaque line of white cellular tissue, different from the rest, may be found in the 

 centre of the mass or beneath each of its lobes, in which vascular tissue makes its appear- 

 ance. Shortly afterwards, the wood of the root upon which the parasite grows appears 

 to become affected ; its annual layers are displaced, and at a still later period vascular 

 bundles, enclosed in a cellular sheath, are found in the axis of the rhizome, and are 

 continuous with those already formed in it. Por illustrations of these stages of deve- 

 lopment see Plates IV. & VI. 



Some genera do not present the appearance of any vascular bundles communicating 

 with those of the root-stock ; but their own vascular bundles may be traced descending 

 to the line of union between the root and tlie parasite, where they become closely applied 

 to the vascular system of the former, without, however, forming any interlacement or 

 organic union. Of this, Lophoplnjtiim and perhaps Scybalium are examples. 



The fully formed rhizomes are roughly divisible into the simple, or merely forked or 

 lobed, and those which are cylindrical, elongated horizontally and branched ; forms which, 

 though exceedingly dissimilar, and associated with very important anatomical details, are 

 not accompanied by such modifications of the floral organs as would afford sectional 

 characters in the Order ; as a comparison of Eelosis with its very near allies, Scybalium, 

 &c., proves. The elongated rliizomes of some species form attachments by their ramifi- 

 cations to the various roots they encounter ; and such never have fohaceous appendages, 

 except at the bases of the peduncles or flowering branches. The amorphous or simple 

 rhizomes again are often provided with scales (as in Cynomorium, Lopliophytum, and 

 Sphcerorhizoii), or with cellular papQlte (as some species oi BalanopJioj'a). These papilla3 

 consist of simple or divided extruded masses of cellular tissue traversed by a furrow ; they 

 are very numerous and cruciate in B. dioica, and are probably intimately connected with 

 the aeration or respiration of the plant ; they present nothing remarkable in structure, 

 and resemble the rimaj with swollen lips on the spongy bark of some Ifenispennece, Vitis, 

 and many other plants*. 



* Jungliuhii says (Nova Acta, xviii. Suppl. p. 223) that B. glohosa is a species wliidi be never found bearing these 

 papillee, except when it grew on the same root with B. e/ongata, when, like that species, it was always provided with them. 



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