ITS TENACITY OF LIFE. 183 



had evidently ceased within. This was the more 

 singular when we remember that the Mytili will live 

 for many days out of the water ; the shells, of course, 

 during the whole period being firmly closed. 



The Mussel, as already hinted, is very tenacious of 

 life. I have kept specimens by accident for several 

 days in the pocket of my coat, but found them quite 

 well and lively when placed in sea- water. 



In general the sure sign of their not being in a 

 healthy condition is when the shell opens; for, while 

 the animal retains any sense whatever, it exercises a 

 strict and judicious ' closeness/ 



I have found, however, on several occasions, that 

 the shell being contracted is not always a valid proof 

 of its owner's convalescence, for when placed in water 

 the Mussel would float for several days upon the 

 surface like a cork, although it was near death's door. 



This phenomenon must be caused, I should 

 suppose, by some sudden fright compelling the 

 mollusc to close its shell with such rapidity as to 

 prevent a proper supply of water being taken in. 

 Having only air to exist upon, the animal then 

 lingers on until its branchiae become dried up, and 

 all moisture exhausted. In this state the Mussel 

 opens its shell with a deep bursting sigh, and sinks to 

 the bottom dead. 



Being at the sea-side one fine summer day, I 

 heard a little Scotch girl cry out to her brother who 

 was about to swallow entire, a fine specimen of the 



