db5 NATURAL HISTORY. 



mended as a strengthening and nutritious diet for con- 

 sumptives. 



The Archil Moss (Roccella tinctoria). Branches but 

 little, erect, cylindrical, gray-green. Grows abundantly 

 on the cliffs of southern Europe, Azores, arid Canary 

 Islands : contains a red coloring matter, which, on the 

 dry plant being powdered, discharges itself in a strong 

 alkali. Blue is also obtained, but through an entirely 

 different process. 



SEVENTY-FOURTH FAMILY. ALG^;. SEA- WEEDS. 

 KELP. Consist of aquatic plants, found mostly in the 

 sea, but some grow in humid terrestrial situations. The 

 highest forms are the proper sea-weeds, Wrack, Tang, 

 Dulse, Tangle, etc., which, spreading their rank luxu- 

 riance through the water, represent extended meadows. 



The Bladder Tang (Fucus vesiculosis), leaves often 

 a fathom in length, banded or ribbed an inch in breadth ; 

 on the stems are found globular cells, which are filled 

 with air, and when put into the fire, explode with a noise 

 like a pistol shot. Found abundantly in the Mediter- 

 ranean Sea, also in the eastern and northern oceans as far 

 as Greenland ; is often driven by heavy floods on land, 

 where it is gathered, dried, and used as bedding straw 

 for cattle ; boiled, it makes good food for hogs ; it is also 

 burned for the sake of its ashes, from which alkaline 

 salts (alkali), containing a large portion of iodine, are 

 made ; therefore the sea tang is very useful, although 

 seemingly a weed. 



There are many relative species of Algoe. several of 

 which, when dried, resembling coarse hair, are used to 

 stuff mattresses, chairs, etc." It. 



* The Le&sonia and Macrosystis, the two giants of the Ocean Flora, 

 are natives of the Antarctic seas. Many as are the beautiful varieties 



