AIR-BLADDERS IN SEA-WEEDS. 9 



these weeds * that lie made such famous whistles 

 when he was by the sea-side. 



" What are the air - bladders for ? " asked 

 Mary. 



" No doubt to support the weeds on the water ; 

 for some of them are of enormous size and length. 

 Dr. Hooker saw them high up in the South Seas, 

 growing in large patches wherever the water was 

 free of icebergs ; the plants were several hundred 

 feet long, and could scarcely have been supported 

 without air-bladders. Around the Falkland Islands 

 they were also very abundant, and sometimes 

 clasped the rocks, and became tree-like in their 

 form, the stems being thicker than a man's thigh, 

 and the long leaves drooping like the branches of 

 a willow. Dr. Hooker tells us that no one who 

 has not actually seen it can form an idea of the 

 amount of life which is nourished and housed by 

 one of these tree sea-weeds. Various kinds of 

 worms, small sponges, corals, crabs, eggs of fish, 

 and myriads of shells, with their inhabitants, find 

 a home there, while the lesser sea-weeds cling to 

 it as moss clings to a large tree." 



"How very different the dark-looking, leathery 

 * Fucus nodosus. 



