98 THE SEA-SHORE 



PLATE XXXII 



THE SERPULA (i and 2) 



If you look down into the pools among the 

 rocks when the tide is out you may often see 

 a number of long, twisted tubes fastened to the 

 surface of the stones at the bottom. These are 

 the dwellings of a very curious sea-shore worm 

 called the Serpula, and if you lift one of the 

 stones out of the water, and look down into the 

 tubes, you will nearly always see a bright scarlet 

 object lying just beneath the entrance. And then 

 you may be quite sure that the animal is alive. 



Now suppose that you carry the stone home 

 with you, just as it is, and put it into a vessel 

 of sea-water. After an hour or two you will find 

 that the little scarlet objects have been poked 

 out of the tubes, and that they are really tiny 

 stoppers, just like little corks, which exactly fit 

 the entrance when they are pulled inside. And 

 you will also find that a plume of feathery objects, 

 which are also bright scarlet in colour, is pro- 

 jecting out of the mouth of each tube. These 

 red plumes are the gills of the worms, and they 

 will often remain spread for hours at a time. But 

 if you startle the animals if your shadow falls 

 upon them, for instance they will draw them- 

 selves down into their tubes in about half a 



