New-York tribune., 1874-06-11
THE TEREDO.
by q. W. r. BAYLEY OF NEW w-0RLEANs, la.

by q. w. r. BAYLEY OF NEw-0RLEANS, LA
The object of the writer in preparing this
paper is possible, to add something to what is gen
orally known of the habits and operations of the Teredo
on timber structures particularly In Southern waters
on the coast OF the Gulf OF Mexico The libraries OF
NewOrleans do not contain all OF the works Of natural
lists and others who have written upon this subject and
have prevented the continuance OF the
writer's observations respecting the habits OF these
"borers Of tho sea-" and OF experiments to ascertain
and determine the best means of preventing their
ravages upon timber foundations under water From
Louis Figuier's Ocean World" We learn that the
Mousca proper have been divided by Cdver into hve
sub-classes; tho first OF these is called Acephaa" To
this subclass tho ship-worms belong. They nave no
head the body Is surrounded by the folds OF the
mantle; the shell consists Of two valves Hence they
called bvayes. because their shell consists OF two
halves Although tney have no head tLey dsed
selves and reproduce their KIND Inc Vaves are umi'eJ
certain muscles. and the mantle looes stretch
caIcareous matter and deposits upon the extreme
edge OF the she'll wnen the secretion nardens ana oe
stance Every newly formed layer enlarges the diam
eter of the she'll The ship worm moves by means OF an
CAPABLE 'u Of being pushed out from the
mantle lobes and the valves and OF adherng Dy the ex
iront end Of the tube tho Teredo engaged in
ya.ing or s %e p the cSa
81 the Gulf q Msico and that they vary very
from haf to three of inch diameter when
fully developed, and from twelve TO twenty more
TTyon gives the dimensions OF the Teredo Norvasca
wnose habitat ia the waters the coasts of Europe.
nch breadth some what less length Of tube, about
foot, but In some che tube Is "a feet
AN EXAMPLE OF THE TEREDO's WORK
The long bridges Bay St. Louis, loOSS feet and
Bay Biloxi, 6.l36 feet. built heavy yellow pine
piles from is 10 inches and In diameter in 1869
aud 1870 had to be reconstructed in the Winter aud
Spring Of by driving entire set OF piles in
place Of those destroyed by the Tcredo The Bay st.
Louis Bridge piles.the new ones5were covered with
felt copper and the Beoxl Bridge pos with felt
and zinc, from the waterne to tho botom tho depth
OF Bay St Louis beng from 10 to u generally and az
piles portion intended to include the space from the
waterne to the bottom was reduced to from Toto u
OF felt and copper yellow metal felt and znc which
was put on At Bay 81 Louis the piles were not
tidal currents aud contraction OF the waterway BY
old bottom. but tho bottom wa: washed
% S' the new paSy Dats below ns tas ess
them exposed to the ravages OF the Teredo below In
after the rebuilding Of these two bridges across Bays st.
Louis and Biloxi, employed diver, who used sub
bridTes This examination showed that many Of the
piles in the Bay st. Louis bridge had been damaged by
sand and clay were hauled in sacisnt quantities and
dumped round the new piles to cover the exposed posts
salt water. aud killing them in few days. The piles
much injured replaced with new ones, previously
clear OIL coated with coal tar varnsh and all loose
broken sheets Of copper were rensied under water
ably thinned by decomposition was good for perhaps
three four years.
As the Teredo cannot penetrate any SOFT. hbrous
spongy substance feng thick paper or the bark OF
pine timber. and this 10 the reason why the spongy,
by Teredo-the preservation Of the felt covering
was certainly matter OF great importance The acton
structive and arred felt better protec ton than
water can penerste under the sheets especially when
loose broken and when sea water ebbs and flows with
the oil Of coa and well coated
with thickened coaitar can be secured to and NAM
considered safe from the ravages Of the Teredo
The sap wood portion OF yellow pine can be easily
round seventy eighty feet length; but
ptchy heart wood cannot be by III very
sap wood is changed and the cracks and checks are
filled with thckened coal tar no worms penetrate
piles and with the bark on II not otherwise to be pro.
tected.
HOW THE ANIMALS WORK Is DONE
The Teredo works In waters all Depths as at the
bottom Pascag0uls Pearl River, the Rigolats, and
Chef Menteur At these places, too, where the depths
vary from twenty TO thirty, forty and fifty feet the
worm not work the surface whore tho water
is fresh or bracssS but beneath IT, In they
ward below IT, as well ss from just below the water line
in AuSS snS
then not largely propagated. When we .have q dry
They probably live 70, one or more years constantly
wood before them 70 bore through and grow in.
"H you examine the living mousks," says Gosse,
you will that the fore part Of the SHE'LL where the
foot protrudes set with stony points arranged In
transverse and longitudinal the former being the
result Of elevated ridges radistng from hinge the
latter that Of the edges Of successive growth of the
she'll These points have the most accurate resemblance
TO those set on steel rasp IN backsmiths shop The
animal turns In its burrow from side side when ut
fore only partially rotating to and fro"
The Teredo probably works in Q precisely analogous
manner by adherine to the front end Of his by
means Of hs foot sucker, and graduating at wifi
the feed Of his rasps which he works by tOand
fro rotary motion It seems obvious when examining
the glitteriug crystalline teeth, SO systematically ar
parallel tho valve shells Of the Teredo
that better could have been adopted for
abraiding, By Q raspng to-and-fro rotary motion
the surface Of hard wood. or OF nything less
hard than the valve shells themselves and not too