Mussel and Cockle. 93 



grounds, specially cared for and protected. As a 

 ship by its cable, so commonly the Mussel, by its 

 bissus or beard, is made fast to its anchorage- 

 ground, be it pebbly or sandy beach, or jutting 

 rock. Sometimes, however, the mollusk travels; 

 and this is how it manages to do so : it has a stout, 

 fleshy foot, in shape something like that of a 

 chubby child, and this it can advance about two 

 inches beyond the edge of the shell, then fixing 

 the point of it to a piece of rock or any other 

 body, and contracting it, the shell is drawn onward, 

 and sure, though slow, progress is made in any 

 desired direction. The Pinna, as the marine Mussel 

 is called, has a foot which is cylindrical in shape, 

 and has at the bottom a round tendon, almost as 

 long as itself, the use of which appears to be to 

 gather in and retain the numerous threads with 

 which, when inhabiting the shores of tempestuous 

 seas, it lashes itself fast to the fixed objects around; 

 these threads are fastened at various points, and 

 then drawn tight by the animal, whose instinct 

 teaches it that its brittle shell would soon be 

 broken in pieces, if suffered to roll hither and 

 thither at the mercy of the waves. 



The Mussel has a very curious method of pre- 

 paring its cable for this service ; it is not woven, 



7 



