å DR. J. D. HOOKER ON THE STRUCTURE AND 
The rhizomes in many species attain a considerable age; but it is difficult to ascertain 
their duration after they have commenced flowering. Helosis seems to be capable of in- 
definite increase; the individual patches of the plant flowering at all or most seasons of the 
year, and the old branches of the rhizome dying as new ones are formed. In Phyllocoryne 
also, the large many-lobed rhizome seems perennial, and to flower at various seasons. In 
Rhopalocnemis and several species of Balanophora, it appears to me as if the rhizome 
continues to increase for several years; and then, after throwing up many peduncles in 
one season, to die the following autumn. Others however, as B. involucrata, which causes 
great knots to form on the roots of trees, either live many years and flower perennially, or 
else a perennial succession of young plants germinate upon the swollen root; a mode of 
increase suggested by the germinating specimen represented in Plate VI. fig. 8. In 
Lophophytum each tuber-like rhizome gives off only one or two peduncles, and the root on 
which it grows forms a shallow cup round its base; which I have found to be of many 
years’ growth. Cynomoriwm appears to be decidedly annual, but I have not examined a 
sufficient number of specimens with the attachment preserved, to decide this point. 
Langsdorffia has certainly a perennial branching rhizome, and Sarcophyte a perennial 
tuberous one. Most of the Balanophoræ have lobed or branched rhizomes, which perhaps 
die after flowering. i 
-. In no case is the vegetation of the rhizome very rapid, in comparison with that of many 
plants; and especially of Fungi, with which some authors have compared them. On the 
contrary, I believe that the growth of all the parts is very slow ; and with regard to Rho- 
palocnemis and Balanophora especially, I have had many opportunities of observing that 
the peduncle did not flower for several weeks after its protrusion from the rhizome. 
The modes of attachment above indicated suggest another division of Balanophoree, 
namely, into—1. those in which the vascular tissue of the parasite is continuous with 
that of the root; 2. those in which the attachment is by means of the cellular ‘system 
only; and 3. those in which bundles of vessels from the root terminate definitely in the 
parasite, a short distance from the point of attachment; the vascular systems of the two | 
plants forming no evident confluence. 
_ Of the first of these classes Balanophora and Rhopalocnemis are the best examples, from’ 
the great development of their vascular systems (which in some species present woody 
zones, à cortical system, and medullary rays), and from the fact that in many instances 
bundles of vessels appear to run in unbroken continuity from the woody system of the 
root to the very flowers of the parasite. 
In the species of this first group, the appearance of the parasite having derived all its 
vascular tissue from the root has given rise to the hypothesis, that the whole production 
is an abnormal development from the root of the plant on which it grows :—thus Junghuhn 
quotes Trattinick (Linnæa, iii. p. 194) as saying of Sarcophyte, * hasce parasitas degene- 
rationes plantarum specificas, sine seminum aditu creatas, modo spontaneo genitas ; ” 
and adds (Nor. Act. Acad. xviii. Suppl. p. 205), * Mihi Balanophorarum vegetatio 
fungosa est, originaria, Succi arborum, e quarum radicibus vivis sanisque Balano- 
phore progerminant, nimis copiosi, cursu consueto perturbati, morphosin arboris redun- 
dantis, ut ita dicam, RETROGRADAM provocant, atque (directione vegetationis mutata) in 
