Perrysburg journal. (Perrysburg, Wood Co., O. [Ohio]) 186?-1965, 1875-06-04
The Ship-WOrm.

The world is indebted to NJ. Quater-
FACES, the eminent French naturalist, for
a knowledge of the life history of the
1eredO nioaLtS, properly called the ship
worm. This destructive little animal
makes its home in submerged wood,
which it perforates with tubular gal
leries, where it spends its life alternately
tunneling and feeding ON the fine rasp-
ings or chips it makes. 1t abounds in
the seas, and its ravages are so extensive
and so rapidly effected that all sub-ma-
rine structures of wood are liable to be
riddled by it unless carefully protected
against its operations. Planks and timbers
of bridges, piers and ships, that appear
outwardly whole and perfect, will often
on examination prove to be internally
furrowed in every direction and ready to
crumble in pieces under the slightest
weight. A piece of deal has been found
completely riddled in forty days after its
immersion. M. Quaterfages relates that
boat raised four months after it had
foundered on the coast near Port St.
Sebastian was so worm-eaten that it was
utterly useless. -+r.-
The curious part of the Teredo's tun-
neling is that, although its galleries may
perforate every part of the wood and de-
communicate. Some instinct informs
the little miner when it has reached a
furrow followed by another individual,
and it instantly changes it's course and
literally worms its way in new direc-
ton. 1t generally moves with the grain
unless it meets with some obstruction.
Early in the eighteenth century the
Teredo attacked the dykes of Holland,
and for time threatened to annihilate
the country by consuming the piles sup
porting the sea-walls, and thus letting
the ocean roll in upon the land. A vast
sum of money was expended before the
imminent danger was arrested But pro-
lection against the Toredo has been found
in iron rust. Timber exposed to its
cravings is rendered safe on being inn
pregnated with oxide Of iron. Copper
sheathing is employed to protect ships,
or the timber is driven full of short,
broad-headed nails, the rust of which
covers it with a coating which is to the
Ieredo like an armOr of mail. Its little
tooth never attempts 10 penetrate ma
terial so spoiled for its taste
Although the Teredo is called a worm,
1t is really an acephalous mollusc, and
wears from its birth little bivalve shell.
| But in the progress from infancy TO
maturity it undergoes singular trans
| formations. 1t is Matched from a small,
round, yellowish-green egg, and is at
| first naked and motionless. 1t is soon
| covered with vibratile ella, after which
1t swims about for forty.eight hours. Al
the end of this time the ella disappear
and the young TOrcdO sinks to the bot
tom. Here, in the course of five and q
half days, it develops a shell that almost
entirely incloses it, Then it gradually
puts forth a long, slender foot that pro
| jects far beyond the she'll and by which
it can propel itself. At this stage it is
the size of a grain of millet, is spherica
in form, and brown in hue, and can swim
freely again, or walk by means of III
foot Now 1t hunts about for some fixe(
or floating wood that is to afford it fooC
and shelter, that is to be at once III
castle and its larder, -,a
When it has found the material neces
sary to its existence it creeps along the
surface of the wood until it discovers
part sufficiently soft and porous, when il
begins boring o gallery for its future
home. After the tunnel is deep enough
to contain it the little, round mollust
rapidly effects metamOrphosis.
covers itself with Shiny coat that a
the end of three days becomes quit
solid. A new and larger shell is mex
secreted, after which the Teredo change
its spheroid form for one elongated lik
worm. 1t requires about three week
for this singular transformation to b.
| completed. Prof. VerTill states that ol
The coast of New England the Tered
| Hf0alfs produces its young in May, ant
probably through the greater part or al
of the summer. According to Quater
iages, the Teredo's life is rounded in
single season. 1t perishes during tn
winter succeeding its birth.