Fig. 370. LYNGBYA CUTLERI^E. 
Colour. A brilliant light grass-green. 
Substance. Very soft and delicate. 
Character of Frond. Excessively slender, gently waved, jointed threads {filaments) ; nn- 
branched ; fixed at base, but forming fleecy layers ; floating freely under water. 
Joints. About as long as broad ; filled with bright green colouring matter {endoclirome), 
which afterwards contracts into a round spot in the centre. 
Measurement. From J to 1 inch long. 
Fructification. Minute seeds {zoospores) formed of the colouring matter in the joints, collected 
into a round central mass {sporidium), which in due time bursts out. 
Habitat. In estuaries. Exmouth, Miss Cutler. But the plant should be looked for further. 
Now Hormotrichum Cutlerice. 
Fig. 371. MICROCOLEUS ANGUIFORMIS. 
Colour. A dull, dark green. 
Substance. Soft ; gelatinous. 
Character of Frond. Dense layers of small, snake-like tubes, tapering at their ends, widening 
upwards ; open at the tops ; forming patches on mud. Tubes filled (when fully 
developed) with numbers of very minute, stiff, straight threads {filaments) ; whose tips 
issue from the open tops, and may be observed (under a microscope) to wave back- 
wards and forwards {oscillate). 
Measurement. The patches about an inch long. 
Fructification. Minute seeds {zoospores) formed of the colour-cells in the filaments'; which 
cells then separate, and in due time drop out. 
Habitat. Coast of Wales. West of Scotland. Pools of brackish water near the shore. 
Fig. 372. OSCILLATORIA LITTORALIS. 
Colour. The mass verdigris-green ; dried filaments deep green. 
Substance. The mass slimy ; filaments elastic ; when dry, membranaceous ; scarcely adhering 
to paper. 
Character of Frond. A thin layer of slender, straight, or slightly-curved threads {filaments) ; 
generally twisted into bundles. Filaments apt to break into needle-like fragments ; 
unbranched ; tubular ; containing very narrow cylindrical colour-cells, which show 
through ; their division-lines conspicuous, at intervals of about one-third the width 
of the filament. 
Measurement. Indefinite. 
Fructification. Minute seeds {zoospores) formed of the colour-cells in the filaments ; which cells 
at last separate from each other and drop out. 
Habitat. Appin. In pools along the muddy sea-shore, flooded by spring tides. 
The filaments of this genus may he observed (under the microscope) waving to and fro 
{oscillating) as if possessed of animal life. For this purpose a morsel should be placed in 
a glass with a few drops of water. The reason of this curious fact is not known. 
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