TEREDO J^AVALIS. 379 



derable proportion of these, from the preservative nature of 

 salt water, would otherwise probably last for ages, form a 

 basis for fresh accumulations, and eventually become pro- 

 ductive of evils, of which it is impossible to form an ade- 

 quate conception. 



Nor is this all. The necessity which these feeble crea- 

 tures impose upon the inhabitants of Holland of continually 

 tarring and repairing their dykes and vessels, forms a bond 

 of union between that country and Sweden, by occasioning 

 a perpetual demand for oak, pitch, and fir. And as these 

 apparently pernicious mollusks are at work at Amsterdam 

 for the advantage of Stockholm, so the labours of insects in 

 the north are equally profitable to the Hollanders, by pro- 

 moting the consumption of salt, spices, and grocery, which 

 are annually exported in large quantities, either for the 

 purpose of seasoning and preserving the provisions of their 

 northern neighbours, or to cure the fish which they use 

 instead of bread. 



Cease, then, to regard these creatures as obnoxious, 

 the use of which you do not readily perceive. The Teredo 

 is apparently an insignificant mollusk ; nay, more, he 

 appears on a slight acquaintance to be absolutely inju- 

 rious : yet the Creator has assigned him an important 



