SERPULA. 



151 



little distance down the tube, and by that sign 

 the living state of the inhabitant may be known. 

 When the serpula is placed in clean sea-water, it 

 generally remains quiet for a few hours, as if 

 to make itself acquainted with the atmosphere of 

 its new home ; by very slow degrees the scarlet 

 object is pushed nearer and nearer to the mouth 

 of the tube, and at last emerges, when it is seen 

 t^o be an exquisitely formed, conically shaped 

 cork or stopper, its small end being prolonged 

 into a kind of footstalk. Two of these stoppers 

 may be seen on reference to the engraving, but 

 they are hardly represented of sufficient size in 

 proportion to the diameter of the tubes. After 

 a little time, a row of scarlet feathery objects 

 slowly follow the stopper, and in a few minutes 

 spread themselves out into a most elegantly 

 shaped plume. 



Slowly as the serpula protrudes itself from the 

 tube, it is by no means slow in retreating. If one 

 of these creatures is fully extended in an aqua- 

 rium, and the hand is rapidly moved outside 

 without even touching the glass, the worm pops 

 back into its tube with marvellous rapidity, so 

 rapidly, indeed, that the eye fails to follow the 

 movement, and the creature vanishes as if by 

 magic. A cloud passing over the sun, or even 



