CH. XV.] CORAL LAND. 247 



manner and on a gigantic scale, by the coral reefs and 

 islands of which we hear so much in accounts of voyages 

 in tropical seas. 



It is extremely common to hear, or read, that these 

 masses of land are constructed by coral " insects." As a 

 matter of fact, however, the animals mainly concerned in 

 the formation of these deposits are widely different from 

 insects ; while they are very similar to certain marine 

 organisms, of much simpler structure than any insects, which 

 abound on our own coasts. 



Scarcely any visitor to the sea-side can fail to be familiar 

 with the peculiar flower-like creatures which are popularly 

 called sea anemones} They are commonly to be found 

 attached to the rocks in little pools of salt water left 

 between tides. The body of the sea anemone is a fleshy 

 sac, more or less cylindrical in shape, and closed at 

 one end, which forms the base, by means of which the 

 creature fixes itself to any solid object. Upon occasion, it 

 can quit its hold and, by movement of this fleshy base, is 

 able to crawl over the sea-bottom. In marine aquaria; 

 sea anemones may sometimes be seen creeping up the 

 glass sides of the tank, in this fashion. At the opposite end 

 of the cyHndrical body, there is a mouth, surrounded by a 

 great number of feelers or tentades, disposed in a circle, or 

 more commonly in several circles one within another. So 

 sensitive are these feelers that, if one be lightly touched, 

 they are all quickly drawn in, and the creature shrinks to 

 a small conical mass, looking like a mere knob of jelly 

 stuck to a stone. But, when the feelers are freely spread out, 

 they form a graceful crown, variously coloured and giving 

 the animal a very flower-hke appearance, not altogether 



^ Anemone, from the flower so called ; from ovf/uoj {anemos) wind, ia. 

 allusion to the flower being easily blown about by the breeze. 



