ULVA 



Seaweeds give homes and food to millions of living 

 creatures. Iodine, potash, and other medicines are 

 made from them. Various kinds of food are obtained 

 from different species. Farmers along the coast every- 

 where use them to make the soil better. So you see 

 that seaweeds have uses as well as beauties. 



ULVA 



You may often find along the beach a plant which 

 looks like the one in the picture. It is an ulva. Some- 

 times it is full of holes. Then 

 you may know that it is an 

 old plant, or that a snail found 

 it before you did. 



The largest bright-green 

 plants in all seas belong to this 

 family. Its brilliant green is 

 darker when the plant grows 

 in deep water. Two species 

 of this seaweed are found on 

 the Atlantic and Pacific coasts. 

 One is called the widest ulva 

 because it is the largest of any 

 of these plants. The other looks 

 somewhat like a lettuce leaf, 

 and is known as sea lettuce. 



The frond of the sea lettuce 



135 



An Ulva. Notice the Hold- 

 fast at the Tip. 



