126 TEREDINID^E. 



a vessel or boat, a harbour-pile, a shipping- stage, a float- 

 ing tree or the roots of one growing on the banks of an 

 estuarine river, a piece of balk timber, a fisherman's cork, 

 a cocoa-nut, a bamboo rod, a walking-stick, a beacon 

 or buoy, a mast, rudder, oar, plank, cask, hencoop, 

 or other ligneous waif or stray of the ocean. These 

 the Teredo perforates, like a rabbit or mole in the earth, 

 for the purpose of making its burrow and protecting 

 its soft and sluggish frame. It is never free, nor found 

 living anywhere except in its wooden gallery ; and it may 

 be cited as a teleological example. Without entering 

 much into the doctrine of final causes, I consider that 

 the Teredo shows an exact adaptation of means to the 

 end or object, viz. its existence. If it were not endued 

 with this or a similar power of self-preservation, it would 

 fall an easy and dainty prey to fish, crabs, and sea- 

 worms; and the race would be soon exterminated. Such 

 is the general aspect of the Teredo. 



2. History. — The ancient history of this mollusk is 

 involved in much obscurity. Homer did not mention 

 in any of his works the word r€p7]Scov. It occurs for 

 the first time in the Knights of Aristophanes, where 

 the chorus reports a conversation that is said to have 

 taken place among some triremes, in which the eldest 

 of them declared to her companions that, sooner than 

 be engaged in a rumoured expedition, she would remain 

 where she was, grow old, and be consumed by Teredines. 

 Now as it was the custom of the Greeks, as well as of 

 the Romans, to lay up their vessels high and dry on 

 the beach, until they were wanted for service, the word 

 T€pr)8cbv, used by the great comedian, may have signified 

 the wood-boring grub of a beetle or moth, and not a 

 shipworm. Nor does it appear that Aristotle was ac- 

 quainted with it. The word is only to be met with once 



