Nostoc piscinale, W ittr. & Nord. Alg. Exs. No. 195.
Nostoc intricatum, Meneg. Nost. Ital. p. 122. Borzi Alghe
Fico. p. 283.
In ditches (slightly brackish).
“ Forming small roundish gelatinous masses, floating amongst different
species of Lemna in fresh wafer, but probably within the influence of the
tide, and also Lnteromorplia i/itesti/lalis, and even within the
frond in brackish water. The plant is at first of an olive yellow gradually
assuming a greener tint, and when dried of a deep verdigris.
gelatinous, delicately branched, the branches very flaccid. Under a high
magnifier the whole plant is evidently composed of gelatine, in the centre of
which runs a single moniliform filament, following the ramifications, and
in its progress curling to and fro repeatedly across the thread, the joints
beiiii nearly globular. The specimens from the interior of Enteromorpha
are paler, and have longer joints amongst the globular ones.”—Bei'keley*
Plate LXXXIX. jig . 1. Nostoc Linkia (intricata) nat. size, after
Berkeley.
Fig. 2. Nostoc completely developed, composed of the interlacings ot
a single trichome X 350. . , ^
Fig. 3. Portion of triohome, spores arrived at complete maturityX b50.
Fig. 4. a, spore commencing to germinate ; b, c, d, e, spores in
germination more or less advanced X 650.
Fig. 5. Germinating filament changed into a hormogoue X 650.
Fig. 6. Free hormogone X 660.
Fig. 7. Motile trichomes segmenting in fragments, of which each
constitutes a hormogone.
Fig. 8. Immovable hormogone commencing to develope X 640.
Fig. 9. Development of hormogones X 650.
Fig. 10. Group of spores germinating X 350.
Fig. 11. Chaplets of spores obtained by cultivation in germination X
650. Figs 2 to 11. After Bornet.
N o s to c p is c in a le . Kutz. Tab. Phyc. II., t. 11, f. 3.
Fronds attached or free swimming, búllate and tuberculate,
verdigris green, rarely nifescent, becoming olivaceous by age.
Trichomes loosely interwoven, joints eqnal in diameter, rather
distant. Spores subglobose.
Siz e.— J oints -OOST-'OOJ mm., heterocysts '006 mm., spores
•007 X -008 mm.
Born. & Thuret Notes Alg. ii., 90.__
Nostoc lacustre, Kutz. Tab. Pbyo. ii., t. 11, f. 2. Eabh. Alg.
E u r. ii., 179. Borzi Alghe Fico. p. 281._
Nostoc agglutinans, Kutz. Tab. Phyo. ii., t. 10, f. 1. Eabh.
Alg. Eur. ii., 178.
In ditches.
Plate LXXXIX. fig. 12. Trichomes of N. piscinale X 400 ; fig. 18,
portion of trichome with heterocyst X 600 ; fig. 14, spores in course of
development, with mature spores X 600 ; fig. 15, spores in the early
stages of germination X 600,
N o s to c c a in e um . Aq. Syst. Alg. p. 22.
Frond indeflnitely expanded, búllate and undulate, flesh
coloured, rufesoent or purplish.
Trichomes loosely interwoven, joints equal, sheath none, indistinct,
or uuooloured, spores oval.
S iz e. Joints -OOSI-'OOI mm., heterooysts '006 mm. diam.,
sp o re s -006 X -009 mm.
Eabh. Alg. Eur. ii., p. 180. Born, and Thuret, Notes Alg. p.
Nostoc variegaiimi, Harv. Man. 183. Kutz. Sp. Alg. 301.
Hass. Alg. p. 287, t. 74, f. 3. , , z a
Nostoc purpurascens, Kutz. Tab. Phyo. u., t. H , 1.1.
Nostoc rufescens, Ag. Syst. 22. Rabh. Alg. Eur. ii., 179.
On rocks.
“ First collected in Ireland in 1836, growing on the face of a moist
bank over which water trickled. When recent it formed a soft gelatinous
mass of a livid colour, bearing the closest resemblance, both in substance
and colour, to those gelatinous medusæ which are cast ashore along the
coast.”—ÑLootCa
Plate XO. fi(j’ 1- Nostoc carneum, natural size ; fig. 2, trichomes
X 400 ; fig. 3, development of spores X 600.
I I Gblatinosa. Fronds soft and gelatinous, adherent, joints o f
trichome cylindrically elongated in the young filaments. Spores
oblong, large.
N o s to c sp o n g iæ fo rm e . Ag. Syst. Alg. p. 22.
Frond at flrst subglobose, then indeflnitely expanded, becoming
rather firm, pale æruginous or olive green, surface
tubercuiated. ^ r • • z
Trichomes heterogenous, composed of two sorts ol joints, one
cylindrical the other cask-shaped, or compressed sphærioal.
Heterooysts globose. Spores smooth, oblong.
S iz e. Jo in ts '004 mm., heterooysts -007--008 mm., spores
•006-^007 X •01-^012 mm.
Born. & Thuret Notes Alg. p. 92. Rabh. Alg. E u r. ii. 178.
Alg. 299. E.M.. Alg. E u r.
ii 171
^Hormosiphon inundatum, Kutz. Tab. Phyc. ii., t, 27, f. 2.
Hormosiphon stagnalis, Kutz. Tab. Phyc. ii,, 't-_27, i. o.
Hormosiphon natans, Kutz. Tab. Phyc. ii., t. 27, i. I .
In wet or inundated places.
Vlnte Xfí Ha. 4. Nostoc spolu/iæforme, natural size ; fig. 5) young
trichome ; fig. 6, mature trichome X 400 ; fig. 7, portion of mature
trichome X 600.