210 Tn£! JiOTTOM OF TBt! SEA. 



This opinion was abandoned when it was observed 

 til at the columns of the ancient temple of Serapis, at 

 Pozzuolis, which had been submerged for many years 

 in consequence of an earthquake, and again restored 

 to the light of day, had been pierced all over by 

 pholades. 



Shut up in a prison from which they can never 

 make their escape, these galley-slaves of the sea con- 

 tinue their work of destruction to the end of their 

 lives, and they have only themselves to blame for 

 their perpetual seclusion from society. Without the 

 least care for the morrow, they go on boring their 

 way through the rock, enlarging themselves and their 

 stony habitation as they advance farther from the sea. 

 The open end of this singular gallery is the gate by 

 which the sea washes in all that these animals need 

 for their nourishment, and for which the pholas re- 

 pays tlie ocean in a perpetual tribute of dust. Every 

 wave carries something into the mine, and brings 

 something away — another and very striking example 

 of the universal work of sedimentation. 



Rocks too hard to be breached by the waves them- 

 selves, are thus eaten away and scattered on the floor 

 of the ocean by the pholades. For others are the 

 transparent waters, the romantic ocean ravines, or 

 the extended plains of sand and mud. The oyster 

 the sol en, and the razor-fisli linger in agreeable situa- 



