-116 HOMES WITHOUT HANDS. 



whole length to a stone or a shell, and others nearly cylindrical, 

 and rearing themselves from the stone after the first half inch 

 or so. 



These are the work of a curious worm, called by Linnaeus the 

 Serpula, on account of the serpentine manner in which its tube 

 is formed. There are many species of Serpula, and some of the 

 more conspicuous among them will be mentioned. 



The Serpula belongs to the Annelidse, or Ringed animals, a 

 very large group, which includes the earth-worm, the leech, the 

 nereis, and many other well-known creatures, all of which have 

 the body composed of a great number of rings, and are destitute 

 of true feet. They breathe either through the skin, by sacs, or 

 by gills, and in the present genus the respiration is by means of 

 gills, wljich are always delicate and elegant in form, and mostly 

 brilliant in color. The body of the Serpula is comparatively 

 short, the tube being frequently six or ten times as long as the 

 animal which made it, and in consequence the Serpula possesses 

 a deep and safe retreat, into which it can withdraw itself when- 

 ever threatened by danger. 



The very fact, however, that the worm lives in a tube, causes 

 the observer to ask himself how the creature contrives to breathe, 

 and how the long tubular shell is kept clean. A reference to the 

 illustration will explain the, former of these difficulties, and the 

 latter will presently be touched upon. 



Projecting from the orifice of the shell may be seen a curious 

 fan-like appendage ; were the illustration to be colored, this fan 

 would have been tinted with the brightest hues of scarlet and 

 white, though no brush could give the wondrous delicacy of 

 the feeling or express its semi-pellucid beauty. This " fan" is 

 composed of the gills of the Serpula, and the animal is enabled 

 to breathe by its power of projecting them from the orifice of its 

 tube. 



If the reader can procure a group of living Serpulas and a little 

 sea water, he is strongly advised to do so, as he will understand 

 their structure far better than can be the case if he merely refer 

 to books. The creatures can be procured at any of the numer- 

 ous shops in which aquaria are sold, and as they are plentiful on 

 our own coast, they can be procured at a very cheap rate. They 

 are terribly apt to die, unless the purity of the water be carefully 

 preserved ; but even in that case they can be dissected, and will 

 afford lovely objects for the microscope. There is always an 



