290 THE SEA-WEEDS AT HOME AND ABROAD. 
in the pulp of the frond in clusters (¢etraspores), the 
others issuing from conceptacles which grow on the outside 
of the smaller branches. On the French coast it is called 
P. vulgare, or the Common Ptilota, and Kützing says that it 
oceurs in the Atlantie, Pacifie, and Southern Oceans. 
The Carrigeen moss, so well known in the preparation of 
food, and to many more familiar on the table than on the 
shores of the ocean, is the Chondrus crispus, really an 
elegant alga. It is subject to many varieties, and the best 
way to study them is to go down as far as you can among 
the rocks at low tides and see the plant growing. A careful 
drying of some of the most prominent sorts will repay. 
Those gathered from the beaches are more or less bleached 
or discolored, and generally filled with sand. In similar sit- 
uations, and even growing where the water is always deep, 
some other alge similar yet distinct may be sought. Like 
others which grow out of reach except by the dredge, they 
are thrown ashore in tolerable perfection during storms. Of 
these the Phyllophora membranifolia may be cited, the 
fronds as much as a foot long when fully grown, the stem 
cylindrical, filiform, irregularly branched, the branches ex- 
panding into fan-shaped flattened membranous leaflets, the 
color a rich purple, inclining to livid, while that of the 
European species is scarlet. The Gymnogongrus which in- 
habits similar situations might be mistaken for the Chondrus, 
looking not unlike some variety of it, but its internal 
structure forbids this. Something like twenty kinds are 
known in the world, and the one most seen in this neighbor- 
hood is G. Norvegicus, having an extensive northern distri- 
bution. 
These black tufts growing out of the stems of the larger 
alge, and from the outside of shells, ete., belong to Poly- 
siphonia nigrescens, of which the curious student could find 
a great many distinct varieties. A section of the frond 
would exhibit a number of tubes, side by side, composing the 
branch, and indeed the entire plant, and those tubes vary in 
