The Shell-builders. 



coloured eyes may be seen amongst them, presenting 

 a most beautiful appearance. If a healthy Scallop is 

 placed in a glass jar filled with fresh sea water, its move- 

 ments can be watched, and a good view of its lovely 

 mantle obtained. The shells will soon begin to open, 

 and then the fleshy mantle can be seen to occupy the 

 interval, like a narrow veil extending perpendicularly 

 from each shell. " The edge of each of these veils will 

 now be seen, if you examine it with a pocket lens, to 

 be fringed with long white threads, which are the ten- 

 tacles, or organs of touch ; and amongst them lie scattered 

 a number of minute points, having the most brilliant 

 lustre, and bearing a close resemblance to tiny gems. 

 Indeed, the mantle has been aptly compared to one of 

 those pincushions which are frequently made between 

 pairs of these very shells, the eyes representing a double 

 row of diamond-headed pins set round the middle." * 



Next to the mantle, the foot is the most remarkable 

 and useful organ possessed by the Mollusc, and is em- 

 ployed in various ways for digging holes in the soft 

 sand, to drill a hole in the hard rock, or as a sort of 

 sand-plough, shovelling the sand away on either side 

 to form a trench, along which the Mollusc moves. In 

 many instances the foot is so large that when it is pushed 

 out it is considerably bigger than the shell from which 

 it has been protruded. The whole body of the animal 

 often swells out to such an extent, as it issues from the 

 shell, that it reminds one of the old story of the Eastern 

 Genii who came out of a bottle. When fully distended 

 it looks as if it were impossible for the creature ever to 

 pack itself away again inside its house. Yet, if alarmed, 



* P. H. Gosse. 

 31 



