Plate XXVII. 
Fig. 119. POLYSIPHONIA VIOLACEA. 
Colour. Brownish-red or purple. 
Substance. Tender ; gelatinous ; soon decomposing in fresh water. 
Character of Frond. Thread-like {filamentous)^ solitary, or tufted ; jointed ; very much branched. 
Principal stem sometimes rather robust ; sometimes much more slender than a hog’s 
bristle ; set throughout with long, irregularly alternate, four-spread {quadrifarious) 
branches, of unequal length, but gradually diminishing upwards. Branches re- 
branched in a similar way with two, three, and even four sets ; these gradually 
lessening in diameter and length ; so that the plant has a remarkably feathery or 
finely bushed character. The last branchlets exceedingly slender, and, when young, 
tipped with fibres. Joints of the stems indistinct ; of the branchlets obvious, with 
two or three upright lines (internal tubes). 
Internal Tubes. Four. 
Measurement. From 6 to 8 inches long. 
Fructification. Of two kinds. 1. Clustered spores in ovate, stalkless, or shortly -stalked, cap- 
sules; external. 2. Tetraspores, large ; immersed in the swollen branchlets. 
Habitat. Our coasts generally. On rocks, stones, and lesser algse near low-water mark. 
Not uncommon. 
Eather like P. fibrata, but a larger and more luxmiant plant, and not obviously jointed 
throughout. The cobweb-like last set of branches are sometimes a beautiful violet colour, 
especially when dried. It is best to lay out this plant in sea-water. 
Fig. 120. POLYSIPHONIA BRODI^I. 
Colour. A dark brownish-purple or red. 
Substance. Gelatinous ; instantly beginning to decompose if immersed in fresh water, and 
giving out a disagreeable smell. 
Character of Frond. Long tufts of jointed threads {filaments)^ very much branched. Stems 
robust, elastic, undivided, opaque. Branches numerous, alternate, rod-like ; clothed 
with short, soft, repeatedly-divided, tuft-like branchlets, from half an inch to an inch 
long. Branching always alternate. Joints not visible in the stems and branches ; 
obvious in the branchlets, which are marked with three or four upright lines 
(internal tubes). 
Internal Tubes. About seven. 
Measurement. From 6 to 14 inches long. 
Fructification. Of two kinds. 1. Clustered spores m ovate capsides, slightly stalked ; external. 
2. Tetraspores immersed in the swollen tips of the finer branchlets. 
Habitat. Our shores generally. On rocks and corallines near low-water mark. Not uncommon. 
This beautiful Polysiphonia should always be laid out in sea-water. The first touch of 
fresh water destroys something of its beauty, by causing the tips of the dehcate, tuft-like 
branchlets to decompose and break off. 
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