BY THE SEASIDE— ANIMAL LIFE 



cannot devote more space to them here. There is 

 the common shell-binder, a curious worm, which 

 builds for itself a still more curious shelter of 

 broken shells. Another worm, Serpula by name, 

 also lives in tube like structures of its own manu- 

 facture and is remarkable in that a row of nearly 

 two thousand seven-toothed hooks run along its 

 back and all these thirteen thousand odd teeth are 

 there merely for the purpose of holding Serpula in 

 its tubular home. 



Much interesting work may be done at the sea 

 side in studying the young stages of various familiar 

 creatures. This work, however, necessitates the 

 keeping of the adults in an aquarium ; for the young 

 ones, in most cases, are so unlike their parents that, 

 if found swimming about on their own account, they 

 would never be recognised. Young barnacles, for 

 instance, have six legs, a tubular mouth and a single 

 eye. At a later stage they might be mistaken for 

 young shell fish; they possess a shell, not unlike 

 that of the mussel, containing, however, not a soft, 

 fleshy mollusc but a six legged creature which 

 swims through the water in jerks, after the manner 

 of a water flea. Strangely enough, it is now pro- 

 vided with two stalked eyes like those of a crab, 

 whilst of mouth parts it has none, or they are so 

 imperfectly developed as to be useless for feeding. 

 Soon this active youngster settles down for the 

 rest of its life and becomes a sedate and sedentary 

 barnacle, with one imperfectly developed eye and a 

 mouth capable of feeding to good purpose. 



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