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infested by this genus, will he described imder M. hracligstacliynm, where only I linve been able to watch that
operation. The present species follows the same course, I presume, judging from the appearance of a fully established
parasite.
The anatomy of the stem and branches of M. pimdiiUtimi not only differs widely from that of M, bmclystadnjim,
but of most other Dicotyledonous plants ; its axis being wholly occupied by very dense fibres apparently of woody
tissue, and presenting there no trace of the cellidm- tissue, whicli is constantly present in such plants as increase
by mmnal layers. The bark of the yoimg branches is thick aud spongy' and a transverse section presents the following
structm-e. 1st. A very delicate hut firm cuticle, striated extenially with lines of extreme tenuity. 2nd. Immediately
beneath this is a cellular tissue forming the epipldoeiim. 3rd. A series of cavities occupy the circiimfeieiice
of the hark ; they are what h.ive been called in other plants respiratory cavities, and correspond each to one of the
tubercles on the surface of the stem ; the cuticle is depressed immediately over the centre, ' where a very evident
stoma is situated. 4th. The cellular tissue forming the mesophloeiim is hexagonal, thick-sided, and very often
full of a green chromule. I have seen no raphides in any of the species, 5th. The liber contains a series of
isolated bundles of delicate fibres (P la t e C V I I ./ 9. a.) frequently, for some part of their length, protected by cells
of great density, such as may he seen in the Lime and Antai'ctic Fagi. The proportion of fibrous tissue to the
thickness of the bai'k is very small, and the fibres composing it exceedingly slender. Between this and the sca-
lai'iform tissue lies a very thick layer of loose hexagonal cellular tissue, formed of membranous utricles, which are
discoloured and compressed immediately ai-ound the annual layers. 6th. The greater portion of the old stem, all
that part which, in Dicotyledonous wood, is usually occupied by plem'enchyma, is here wholly, or nearly, fonned
of elongated variously marked tubes, of almost equal diameter, they are white and diaphanous, dotted, ringed, transversely
barred, or contain a spiral vessel, more or less broken (P la t e CVII. / . 8, 9 and 10, e.). I have not
observed simple or thick-sided tubes of pleurenchyma, true tracheæ, or bothrenchyma, either in the inner portion
of each annual layer, or in the usual position of the medullary sheath. 7th. The axis of the stem is formed ivhoUy of
a dense tissue of woody fibres (P la t e C T II./y s. 8. 9 and 10 b.) the tubes aU very small, inseparable, even after long
maceration, and their walls so thick that it is difficult to trace the dark longitudinal Mne which indicates their
carity which contains granules, though a dot in the centre of the transverse section of each fibre is very evident.
Tliis axis suffers no change after the first year’s growth, and at that period may he seen to project wedge-shaped
plates in the manner of medullary rays, into the scalariform tissue which it h.ai'dly divides.
The stems of this plant are, though hai-d in texture, very brittle, especially when dry, owing p.irtly no doubt,
to the fragile nature of the scalariform tissue, and probably stUl more to the very small quantity of parenchyma aud
the axis being fonned of a denser substance than auy other p a rt.
The ramification of this plant is highly peculiar, and uniformly takes place in the following manner. Each ultimate
branch, when fully formed, P late CVII. b is ,/. 1, (and the plant itself, when consisting of a single imbranched
stem) elongates no further in any succeeding year, but gives origin, towards its extremity, to five or six latend amenta ;
these arise from the centre of a depression, bounded by a low cnp-shaped sheath (P late C IV ./. 1), All but a few of
the upper of these amenta are floriferous ; they fall away after they have performed their functions, leaving a cicatrix
on the ramulus, very visible even on the oldest stems, below every ai-ticulation. The upper empty amenta, however,
(P late CVII. his, f . 1, d), elongate during the autumn, one or both of them, causing the ramification to be
frequently either alternate or dichotomous ; the bracteæ are separated during tliis elongation, become recnrved, *
fall off and leave a naked newly-formed branch (Plate CVII. hie,/, b.), fully developed by the month of September;
toward the upper part of this, other amenta are formed and the process is repeated. The apex of
the originally ultimate branch, now a stem, is reduced to a mere point (c), always discernible close to the articulation
even of the oldest stems, though often veiy inconspicuous, OccasionaUy, three amenta are developed into branches, but
this effecting a trichotomous ramification, is rare. The articulation of the stem in Myzodendron is therefore of a
* As figured in De CandoUe’s Coll. ; vi. 1.11. f. AandB,
Falklands, e tc ] ELO EA ANTAECT ICA .
very different nature from what occurs in pknts, whose joints indicate an interruption of contmmty m a rectilinear
organ, as tho stems of Equisetum, Casuarim, or Salicornia, or from those which increase by new matter being
developed at certain intervals from the apex of the axis of growth, as the trunk of a Palm. In Fiscum album, the
ramification is truly dichotomous, each internode giving off two opposite ramuli from its apex, between wliich is a
third undeveloped bud ; aud in V. salkmioides and ArcmOmlobium oxycedri the branching is trichotomous, from
both the lateral and terminal branches being developed. Another modification is observable in a singular new genus
of Lorantlmceie, EiAradiion* mihi, (Vismm ambiyuum, H. et A.). The ultimate ramuli of this plant are jointed on
tho stem and appear not to ramify further, but to bear amenta simUar to the bracteate spikes of i f . punctulaium,
aU of which arc fertile and caducous, the ramidns elongating and producing year by year new amenta, as the old
onc3 tli-op away.
The axis of the stem and branches of M. punctulaium is remarkably eccentric, the greater quantity of scalariform
tissue being deposited on the under side of these organs, a oii-cumstance arising from the horizontal direction the
whole plant assumes. An analogous eccentricity in the position of the meduUa in the horizontal branches of
ooniferous trees is very evident, though not so conspicuous, in other woody plants whose stems are as slender
as those of Myzodendron. The truly amentaceous infiorescence of this plant is common also to Anlidaphne,
EubraoVion, Lepeostegeres, Blume, Tupeia and others of its congeners, if examined at an early stage. The male
flowers arc abundant, and tbe females much rarer in Heimite Island, this preponderance of males was also very
mai’ked in tlie M. brachystacJiyum.
Mr. Brown t first observed the singular position of the stomata in this species, which are placed one on the
apex of each tubercle of the stem, and communicate with the carity or chamber beneath, the respiratory cavity
ot some authors. The cells ot which the cuticle is composed are so completely incorporated into a uniform
integument, that the curved utricles, which bound the mouth of the stoma in most plants, arc here hardly apparent,
though it is to their presence that the ridge (P l.ite CVII. bis,f. 6, a) is due. The aperture itself, as seen in
/ . 5 and 6 of the same Plate, is constricted in the middle, somewhat in the form of an hour-glass, but au opening
is generally, perhaps always, left between the adjacent edges of this constriction or diaphragm. The stoma thus
expands both outwardly and inwardly into a sort of cup, the outer of which is frequently filled with an opaque mass,
and the chambers beneath traversed by filaments of a viscid substance stretcliing from one waU to the other ( / . 5).
In the external cavity, when empty, parallel concentric Hues may be obseiwed, indicating the compound nature of
the walls of the apertm-e. These stomata are abundant on all siu-faces of the young stems and branches, bnt only
011 the loiver siu-face of the older and horizontal stems.
Male eloweks. These ai-e of the most simple stractiive, consisting of a solitai-y cun-ed subolavate peduncle
in the axil of each bractea, bearing at its apex a lai-go broad depressed gland, on each side of which an anther is
seated. (P late C IV ./. 3, and 4). There are no traces of a floral envelope. Tlie anther is ovoid. one-ceUed,
opening by a small transverse slit at the apex, and containing a membranous columella, which is the remaining
imelaborated tissue from which the poUcii is formed, the indication of the anther being originaUy bUocidar, as may
* E u b h a ch io n , Nov. Gen. Infiorescentia amentacea. Amenta hermapbrodita, flores compressi. perianthio
trifido segmento dorsali minore. El. Masc. Stamina 3, segmentis perianthii opposita, filamentis breviusculis,
antberis compressis latis bilocidaiibiis. E l. Ecem. Omrium infernm compressum, disco epigyno latiuscnlo, stylo
breviusculo, stigm.ate simplici. Fructus ovato-globosiis, compressus, carnosus, sarcocarpio viscoso supra loculum
posito, endocarpio siibcrustaceo superne aperto, embryone tereti, cotyledonibus albumine late disciformi immersis.
E. Arnottii. Viscum ainbiguiim. Hook, et Arn. in Lot. Misc. vol. iii. p. 356.
H ab. Uragmay ; Tweedie.