NOTES. 55 



Note '', page 3S, line 2. 



I would not doubt ivith impious mind, 

 Teredo ! good in thee to find. 



Teredo Navalis, or ship worm, readily enters the stoutest tim= 

 ber, and ascends the sides of stately vessels, which it insidiously 

 destroys. When the body of a vessel continues for any length 

 of time under water, the Teredines appropriate it to their own 

 use. They commence their operations by perforating the softest 

 parts of the wood, and, as they have seldom at this time attained 

 their full growth, the perforations are so small as to be scarcely 

 discernible. As soon as they have entered and completed their 

 habitation, they begin to beautify and render them commodious, 

 this they effect by means of a white glutinous fluid exuding from 

 their bodies, like the viscous juices of the common snail, which 

 hardens into a sort of crust, and forms a thin smooth lining to 

 their respective shells. This lining by filling up the cavities, 

 and smoothing every inequality, protects their tender bodies 

 from being injured b}^ the roughness of the wood ; it also enables 

 them to move in various directions without inconvenience. A 

 social compact apparently subsists between these shelly anchorites, 

 as the greatest care is evidently taken to avoid injuring each 

 other's habitation. Each case or shell is preserved entire, and 

 even where a piece of wood has been so completely perforated as 

 to resemble a honeycomb, the slightest passage or communication 

 has never been discovered between the different compartments 

 though the divisions have frequently not exceeded the thinness of 

 fine writing paper. — Philosophical Transactions 



The destructive operations of these insidious animals, are, in 

 a great degree, obviated by the singular fact of their generally 

 perforating the wood, in the direction of the grain. 



