'204 transactions liverpool biological society. 



Eighth Day. 



The Cockle. 



Structure. — Mouth and stomach, foot, siphons, 

 gills, manner of feeding and breathing; male and female 

 cockles. 



Food of cockl e. — The cockle like the mussel 

 and oyster feeds by " suction." It gets its food from the 

 diatoms and other microscopic life which are present in 

 the water sucked into the shell by the action of the gills. 

 These diatoms, &c, are to be seen in the intestine of the 

 cockle, mixed with a great quantity of sand and mud. 



Exh alent 

 .Inhalertt 



Diagram of thejstructure of a Cockle. 



The Oyster. 



Structure of oyster — mouth, palps, gills, stomach, 

 heart. 



Manner of feeding and breathing. 



Male, female and hermaphrodite oysters. 



Different kinds of oysters — Deep-sea oysters, 

 American oysters, Portuguese oysters. 



Tropical oysters, pearl oysters, pearls and pearl shells. 



Pearls in the common mussel. The parasite which 

 is the cause of the pearls. 



Artificial cultivation of oysters in France. 



