TEREDO NAVALIS IN NOVA SCOTIA —- MURPHY. 367 
heart of the timber; the Limnoria attacks from the outside only, 
and rarely more than one half an inch, until the cells are des- 
troyed by the water, when it renews its efforts and destroys again. 
From these facts it will be seen that the preventive measures 
to be taken in order to counteract the attacks of these two 
classes of borers, should be quite different. For instance: the 
means to be devised for the preservation of wood from the at- 
tacks of the Teredo in the harbour of Pictou should be entirely 
different (preventively considered) to those which should be em- 
ployed in the harbour of Halifax. To arrest the destruction 
going on by the Limnoria Lignorum, one means must be used so 
as to permeate every pore of the wood internally ; the other need 
only to be applied externally, so as to fill up the half inch cavi- 
ties or cells visible on the outside of the timber, or both destroy- 
ers may be warded off by a metallic covering, so as to prevent 
them from attacking the wood at all. 
That the Teredo existed in Europe, in a geological period ear- 
lier than our own, does not admit of a doubt. At Belfast, Ire- 
land, 12 feet under the surface in a blue argillaceous soil beneath 
a series of strata of shells, in the London clay, in the Eocene for- 
mations at Brussels, and also near Ghent, fossil wood containing 
the remains of the Teredo has been found. 
An idea prevails that the Teredo was imported from abroad 
through vessels coming from the East Indies to Europe; but this 
is said to be an erroneous impression. The same idea prevails 
here, that it was imported from the West Indies through the 
same means, and it may be found equally fallacious. It is ob- 
vious that the Teredo in Nova Scotia does not seek the most 
southern and warmest haunts. 
One of the circumstances favoring the ravages of the Teredo is 
said to be saltness of the water ; it is not found in brackish water 
here; and owing to the narrowness of our Peninsula (not more 
than 100 miles at the most) the small consequent water sheds, 
and the small volume of water poured from them into our har- 
bours, we cannot say much on this point. I have, however, no- 
where observed the Teredo active near fresh water. 
The Teredo finds himself exposed to the attacks of an anne- 
