100 SEA-WEEDS. 



varied markings or brilliant tints, and they are 

 attached by their flat sides to the sea-weed ; but the 

 beautiful animal within, when seen under the micro- 

 scope, excites our admiration by its symmetry and 

 grace ; and its shell-like case was secreted, like the 

 home of the mollusk, by its outer covering or skin. 

 Another of the most common of our marine 

 plants, and one of our largest kinds, is the 

 Knobbed or Knotted Fucus (Fucus nodosus). 

 It is a thick leathery plant, of an olive-green 

 often almost yellow colour, when fresh, but when 

 dried, of a black hue, and polished like ebony. 

 It may easily be known by its long stem, which 

 swells at intervals into large bladders, in fine 

 specimens an inch and a half in length, and look- 

 ing altogether like a string of beads. The air- 

 vessels are said to be used, when highly polished, 

 for necklaces. It has, when in fructification, 

 orange-coloured pods, on little stalks ; hence the 

 people of the Orkney Isles call this plant Yellow 

 Tang. In Norway its large air-vessels acquired for 

 it the name of Knop Tang. These bladders are 

 admirably adapted to the condition of the plant, for 

 it is course and heavy, and when growing in deep 

 water, it is seven or eight feet long ; so that the 

 stormy winds, which upraise the waves, dash it 

 with great violence against the rocky peaks. Were 

 the bladders of more delicate structure, and frailer 

 substance, it must inevitably be torn to pieces by 

 the force of wind and waves. Were they like 

 those of the Bladder Fucus, which break by a 

 gentle pressure of the finger, they would not suit 

 this plant. But the Bladder Fucus grows in a flat 

 branch upon rocks, and needs not the provision of 

 a stronger fabric. The Knobbed Fucus is known 



