IN FEATHERS AND FUR. 325 
positively known. All we are sure of is that he docs make a long 
tunnel, and as he goes on, he lines it with a sort of shell, in which 
he lives. Meantime, he is growing longer and longer, and having 
no more use for ears and eyes, he loses them, and at last comes to 
be the long slim fellow I described to you, spending all his life in a 
hole just big enough for him, eating and breathing, and no doubt 
just as happy in his way, as beings of a higher organization. 
The common Ship Worm has a relative called the Giant 
Teredo, who sometimes grows to the length of six feet, and the 
diameter of three inches. Happily, this great creature don't like 
wood for his house, but bores into the hard mud of the bottom of 
the sea. This fellow's shell is half an inch thick, of a white 
color, and very hard. He is found in Sumatra, and was first dis- 
covered on the occasion of an earthquake which threw up great 
masses of earth from the bottom of the sea. In this dried mud 
was found the Giant Teredo calmly reposing in his monstrous 
tunnel. 
There is still another of this boring family, who prefers for a 
residence the wood of cocoa-nuts, and other hard shelled fruits 
growing in the Tropics. Of course he is unable to make a straight 
tunnel in such a small space, so he winds about and his long scien- 
tific name means horn-shaped. 
The Teredo has the honor of having suggested to English 
engineers the plan of tunnel building which was first applied to 
the construction of the Thames tunnel. 
