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161 RADIATA DIAGRAM 7 



SUB-KINGDOM RADIATA. 



This .sub-kingdom includes animals of very simple organisation, 

 all the parts of which branch from a common centre. 



The most remarkable of these animals live in the sea. They 

 are generally formed of hard or horny parts, and very soft parts 

 which cover these, such as the coral, sponge, &c. 



Red coral grows in branches attached to the rocks. They fish 

 for it in the Mediterranean with nets of iron wire, which catch it 

 in their meshes and break it. When the coral is alive, its 

 branches are seen to be covered with pretty star-like flowers with 

 eight petals. But on looking at these supposed flowers, we soon 

 see that they move, and that their petals open and close, and 

 lengthen and contract. Each of these is an animal, and it is this 

 which gradually forms the coral, as the oyster forms its shell. 

 Coral therefore only resembles plants because it has branches, but 

 it is in reality an animal. The kind used in trade is of a fine red 

 colour. But there are many other corals in the sea which are 

 white, and are called brain-coral, sea-mushrooms, <kc., from their 

 fancied resemblances to various objects. 



Sponge. Another group of these singular creatures is the 

 sponge, which is found at the bottom of the sea, and is also an 

 animal. There are many small species of sponge found in the 

 British seas ; but the kind used for household purposes is found, 

 like the red coral we have just mentioned, in the Mediterranean. 

 When it is found in the sand, it is heavy, and full of a glairy flesh 

 which is allowed to rot, and is the living part of the sponge. 

 When all this has been removed by repeated washings, the horny, 



