TEREDO NAVALIS IN NOVA SCOTIA — MURPHY. 3C7 



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 find's himself exposed to the attacks of an anne- 



