64 CIRRI OF BARNACLE 



The stones and pillars near the jetties at 

 the seaside are often to be found covered 

 with acorn-shells. If a stone so encrusted be 

 placed in a glass vessel of clear sea-water, the 

 delicate plumes may be seen opening out and 

 then retracting. The protruding and retracting 

 processes are accomplished with regularity and 

 order. These form the creature's fishing- 

 tackle. They are prehensile and flexible, and 

 consequently are admirably adapted to catch 

 any nutritious particles within their reach. 



The sense of touch is exceedingly keen in 

 all parts of these wonderful casting-nets. By 

 the constant movements which the cirri keep 

 up, currents are formed which bring food- 

 particles within their grasp and on to the 

 mouth. The barnacles in the adult stage fix 

 themselves by a fleshy stalk to any suitable 

 object shells, drift-wood, ships, &c. and 

 develop a peculiar multivalve shell. The 

 acorn-shells attach themselves directly, with- 

 out any stalk, to stone or wood. 



Sometimes after a long voyage the bottoms 

 of ships have to be freed from the barnacles. 



