SEA-WEEDS. 



BY PETER GRAY. 



ALGJE, popularly known as sea-weeds, although many species 

 are inhabitants of fresh water, or grow on moist ground, may 

 be briefly described as cellular, flowerless plants, having no 

 proper roots, but imbibing nutriment by their whole surface 

 from the medium in which they grow. As far as has been 

 ascertained, the total number of species is about 9000 or 10,000. 

 Many of them are microscopic, as the Desmids and Diatoms, 

 others, as Lessonia, and some of the larger Laminarise (oarweeds), 

 are arborescent, covering the bed of the sea around the coast 

 with a submarine forest ; while in the Pacific, off the north- 

 western shores of America, Nereocystis, a genus allied to Lami- 

 naria, has a stem over 300 feet in length, which, although not 

 thicker than whipcord, is stout enough to moor a bladder, barrel- 

 shaped, six or seven feet long, and crowned with a tuft of fifty 

 leaves or more, each from thirty to forty feet in length. This 

 vegetable buoy is a favourite resting place of the sea otter ; and 

 where the plant exists in any quantity, the surface of the sea is 

 rendered impassable to boats. The stem of Macrocystis, which 

 "girds the globe in the southern temperate zone," is stated to 

 extend sometimes to the enormous length of 1500 feet. It is 

 no thicker than the finger anywhere, and the upper branches 

 are as slender as pack-thread ; but at the base of each leaf there 

 is placed a buoy, in the shape of a vesicle filled with air. 



Although the worthlessness of Algae has been proverbial, as 

 in the "alga inutile" of Horace and Virgil's " projecta vilior 

 alga," they are not without importance in botanical economics. 

 A dozen or more species found in the British seas are made 

 use of, raw or prepared in several ways, as food for man. 

 Of these edible Algoe, Dr. Harvey considers the two species 

 of Porphyra, or laver, the most valuable. Berkeley says, " The 

 best way of preparing this vegetable or condiment, which 



