i l
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Hoimospoxa tx an sv e z sa lis. Breb.
Tubes slimy, equal or u n d ulate: cells ovate-oblong or fusiform,
disposed transversely in a moniliform se ries; contents
granular.
S i z e . Diameter of tube -075--12 mm.
Eabh. Alg. iii. 49.
In bogs.
Plate X . Jig. 3. a, portion of filament X 200 diam. j b, portion X
400 diam.
** Tubes branched.
Koxmospoza ramosa. Thwaites.
Tubes broad, gelatinous, irregularly branched ; cells oval or
nearly cylindrical, obtuse at the ends, either remote from each
other or connected, twice as long as broad ; contents green,
with green lamina radiating from the centre.
Thwaites in Harvey Phy. Britt, t. 213. Eabh. Alg. iii. 49.
In brackish and salt water, attached to Cladophora.
The filaments in this species, unlike those of the preceding two
species, are branched.
Plate X . Jig. 2. a, portion of filament X 200; b, small portion with
cells X 400.
G en u s 16. CYLINDROCAFSA. Beinsoh. (1867.)
Cells sphaerical or ellipsoid, membrane thick, either with a
three or fourfold tegument, or naked; cells associated in a
linear series in families, enclosed in a cylindrical hyaline gelatinous
tube ; cells dividing transversely. Propagation by
gonidia uncertain. Cell contents green, granular, with a single
chlorophyllose corpuscle.— Beinsch Algenjlora, p. 66.
Cylindrocapsa in v o lu ta . Beinsch Algenjlora, ta b .Y i.f. 1.
Cells ellipsoid, ultimately involved in a fourfold tegument,
which is expanded at the poles.
S iz e . Cells ‘023-'03 mm. diam.
This plant has occurred in Ireland, as recorded by Mr. W. Archer, in
“ Grevillea” (Vol. iii. p. 40), with the following observations:—
“ Admitting the identity, of which I myself do not doubt, though not
previously having seen examples, that author’s description of this
minute alga does not appear quite complete, as he omits to mention that
the cylindrical hyaline envelope of the cells, combining them into a
frond, is closed at both extremities, rounded off at the upper, and somewhat
produced, tapered and thin, slightly dilated into a scutate organ of
attachment (to foreign objects) at the lower extremity. Thus the extremities
appear to be differentiated iuto a basal and apical. The Irish
plant agreed with Eeinsch’s in the dimensions of the cells, their oval
figure (truncate after division, whilst closely apposed, and until full size
is again attained), their longer diameter posed in the direction of the
length of the cylindrical filament and in their being involved by a
number of concentric hyaline investments standing off from the cells at
the poles, closely applied at the sides ; not, however (as Reinsch shows)
uniformly fo u r, but two, three, or four, and standing off from the cells,
not equidistantly, but at different distances. I t is, however, quite
possible that where the fewer number only of laminæ of the envelopes
were apparent, others may have been present, but so closely applied to
the cells (and to each other) as to appear as if absent. Just as depicted
by Reinsch (though his figure be rather stiff), I saw some of the cells
undergoing self-division, the fission always taking place through the
shorter diameter, the new cells, at first flattened a t the ends, then growing
as long as the older, and becoming rounded off, and thus the longitudinal
direction of the cells is maintained. Thus this form is unlike
Cylindrocapsa nuda (Reinsch), in which the oval cells are placed transversely,
and appear to be without the loose outer envelopes. The
author does not state that the contents are not a bright, but a dull lurid
green, very opaque. On endeavouring to preserve this plant, it ‘ kept ’
not at all, colour became lost, envelope shrivelled, and even after a
couple of days the examples did not represent the same thing as when
fresh.
“ Thus the morphology of the plant points to an affinity with Hormo-
spora, Breb,, which, too, has its forms with the elliptic cells placed
longitudinally {H. mwtabilis and others) and transversely {H. transver-
salis), but no Plormospora, except Jp ramosa, Thwaites, appears
attached ; the contents, too, are bright green, and seem to show a
characteristic internal arrangement not seen in Cylindrocapsa ; the
outer investment is also more mucous. As a form, or a form-species,
(for, doubtless, such as those belonging to Cylindrocapsa and Ppwrno-
spora can all be accounted no more, so long as no reproductive process
is known) the present plant (Cylindrocapsa involuta) is, per se, abundantly
distinot. I t appears to be very rare, so does C. nuda,
which I only once met with ; neither is recorded by Rabenhorst in
‘Mor. Europ.’
“ But whether these Cylindrocapsa-forms be mere stages of other
growths—mere form-species—or permanent parthenogenetic species—
they are entitled to hold a place for purposes of reference until happily
more be, if ever, known as to their development and their right to
rank as independent plants.”—Grev. iii. 40.
Plate I X . Jig. S. Portions showing spores X 400 diam.
Cylindrocapsa n u d a . Beinsch Alg. p. 67, t. 6, /. 2.
Undivided cells ellipsoid, membrane thick, without teguments,
filaments now and then thickened and enclosing four cells.
S iz e . Tube •023--08 mm. diam.
In streams. Ireland.
Cienkowski’s* researches on Cylindrocapsa involuta achieved such important
results that they must be indicated here, since the reproduction
■will, doubtless, be identical in both species.
“ This alga possesses antheridia and oogonia. The oogonium is a
globular inflated joint, it consists of contents and wall ; the first presents
* Cienkowski, “ Zur Morphologie der Ulotrioheen,” in Melanges Acad.
Imp. de St. Petersburg, t. ix. p. 531.