324 LITTLE FOLKS 
the waves. He is so common that no wood is safe from him, and 
ships have to be protected by metal covering, and piles by nails 
driven into them so that he cannot drive his tunnels. 
He is a curious looking fellow, more like a worm than a mol- 
lusk — which he is. He is about a half an inch thick, and a foot 
long. At one end of his body is a pair of curved shell valves, and 
at the other, a forked part, containing the siphon or breathing 
tubes, such as I described in the Pholas. His color is very light 
gray. 
As he bores out his curious home in the wood, the Teredo 
lines it with a thin shell, and the burrows are sometimes so near 
together that it is not thicker than a sheet of paper between them. 
Many a bridge has fallen because its timbers were destroyed by 
this dreadful little creature, and many a ship has gone down with 
all its crew because of the same industrious Teredo, Holland was 
at one time threatened with total destruction by a sudden attack of 
Teredos on the piles which support the dikes that keep the sea 
from that curious country. 
But he was not always a contented prisoner in his own house. 
When the Teredo was first hatched from a round greenish colored 
egg, he looked more like a tiny hedgehog than anything else, 
being covered with little hairs or spines. These hairs, by their 
constant motion, helped the little creature to get about in the 
water, and very lively he was for about a day and a half. Then his 
first change takes place, his skin bursts open and becomes a shell, 
and he has a new set of swimming organs in the shape of a sort of 
collar of the movable hairs, which acts something like the paddle 
wheel of a steamer. 
But now — as he grows older — the curious creature begins to 
long for the quiet which he finds in his wooden home, and a new 
organ shows itself, namely, a sort of foot, by which to hold on to 
one spot. This foot can be lengthened or shortened, and indeed 
looks more like a tongue. At this stage of his life he can hear 
and see also. But his last change approaches ; he seeks a piece of 
wood along which he creeps till he finds a point which exactly suits 
him. There he stops, fastens himself there, and begins to bore out 
his future house. How he does it is not yet known. It is not by 
working himself around as the Pholas bores, for he can't do that, 
but whether by the aid of a fluid which he secretes or by working 
his head against the wood already softened by the sea water, is not 
