188 FOOD OF THE MUSSEL. 



when we consider that the Mussel is always affixed 

 to some foreign substance, that it cannot hunt after 

 prey, and therefore can subsist only upon whatever 

 nutritious particles may be contained in the element 

 in which it lives. These consist of minute animal- 

 culse, principally Crustacea, which are drawn within 

 the shell by powerful currents. 



I have often watched this phenomenon through a 

 hand lens, and have seen the young shrimps and 

 skip-jacks, for instance, notwithstanding the nimble- 

 ness of their movements, irresistibly drawn into the 

 gulf of destruction. Even tolerably sized specimens 

 that were seated in fancied security upon a valve of 

 the Mussel, have suddenly been drawn in, out of 

 sight. As an instance of the power of these cur- 

 rents, I may state that the water in a small aquarium 

 is often seen to be affected by the respiratory action 

 of a single bivalve. The same thing has even been 

 apparent to the writer, while watching the move- 

 ments of a colony of Barnacles attached to a Limpet, 

 the most distant part of the fluid being gradually 

 drawn near, in obedience to the beck of these delicate 

 and graceful little creatures. 



