ZOOLOGICAL SOCIETY BULLETIN 
M2 
Work of Limnoria. The pile was two years in service. 
The clam-like larva now seeks a wooden 
structure in which to bore. Perhaps it is at¬ 
tracted to wood by soluble substances of the 
wood dissolved in the sea water. When it 
alights on a wooden surface the sticky thread 
holds fast, the shells gradually transform into 
the boring apparatus, and the burrow is started, 
at first transverse to the grain of the wood but 
ordinarily turning if possible and running in 
either direction with the grain of the wood. As 
the burrow is excavated it is lined with pearl, 
the teredo elongates, develops pallets and 
grows at a tremendous rate. When it began 
to bore, it was probably not over 1-LOOth of 
an inch long. In a month it can be over two 
inches long, and may be ready to produce young. 
The spot where the larva attaches remains as 
the point of contact of the adult teredo with 
the outer world. A teredo does not change 
its home, neither does it burrow into its neigh¬ 
bors’ homes although at times space in a pile 
or board is at a premium. 
When one thinks of a single teredo pro¬ 
ducing several batches of millions of larvae in 
a single season and even living over the winter 
to reproduce a second season, one wonders why 
these animals are not omnipresent. But teredo 
like other animals requires its own particular 
conditions in which it can live and reproduce. 
Even different kinds of shipworms have dif¬ 
ferent demands; teredo likes brackish water 
but bankia prefers it much saltier. Undoubt¬ 
edly conditions about large cities like New 
York where sewage and chemical wastes are 
cast into the sea have caused teredo to be less 
destructive than it ordinarily would be. But 
even now close to Manhattan Island teredoes 
are tirelessly burrowing into piles at such places 
as Staten Island, Bayonne, the Narrows, Coney 
Island, Sandy Hook, Long Island Sound, Ja¬ 
maica Bay and Great South Bay. If favorable 
conditions for them should prevail, those places 
could furnish the larvae to extend the deadly 
work. 
Old burrows of shipworms which extend from 
the mud line to about low tide level are often 
used as homes by marine worms and little crabs. 
These organisms most of them segmented worms 
DOUGLAS FIR AND SOUTHERN I'INE PILES 
Left: Douglas fir from Seattle Harbor showing destruction in four years. Right: Southern pine from 
Biloxi, Miss., section taken between medium and low tides, after three years service. 
