XIV.} ALG. ~ 203 
plant. In an allied species, Fucus nodosus or Knotted 
Wrack, of which we give an illustration (fig. 151), the 
bladders look as though strung on a line. This 
species attains the length of six feet. In Haldrys 
siliquosa the bladders very strongly resemble the 
seed-pods of the furze. To this group also belong 
the long, broad, olive fronds with crisped edges so 
frequently brought from the seaside to act as an 
indicator of the amount of moisture in the atmosphere. 
Its name is Laminaria saccharina, and, like its allies, 
L. digitata and L. bulbosa, it grows to an immense 
size. These plants annually lose the outer coating 
or Jamina of their fronds, which falls off, revealing a 
new frond which has been formed within. They are 
most plentiful in the north. Another species re- 
sembles a gigantic leather bootlace, from twenty to 
forty feet in length. This is the Chorda filum, or 
Sea-lace. The frond is hollow and slimy, and when 
growing in the quiet waters of land-locked bays, 
attains its greatest dimensions, In the Carrég 
Roads, off Falmouth, we have seen great areas of 
water occupied by this species, which sometimes 
obstructs to some extent the passage of boats. It is 
said seriously to endanger the life of the unfortunate 
swimmer who happens to pass through a bed of these 
tenacious laces, by clinging to his limbs and entang- 
ling him in a network from which there is no escape. 
In the genus Lessonia the species form submarine 
forests, the stems attaining the diameter of a couple 
of feet. The dead stems when thrown ashore are 
often mistaken for driftwood. They are said to be 
used with great success as the handles for knives and 
