TEREDO. 131 



admiration of its symmetry, economy, ingenuity, social 

 harmony (especially in avoiding controversy and liti- 

 gation !), and its wonderful perfection in every par- 

 ticular. His account would almost persuade us that its 

 dwelling is a model for the architect, and its mode of life 

 a rule for the Christian. The observations of Sellius 

 with respect to T. navalis are so interesting, and on the 

 whole so correct, that I trust I may be here permitted 

 to republish some of them, although they are antiquated, 

 with such comments and explanations as I may deem 

 necessary. If the perusal should occasionally provoke 

 a smile, may it be one of charity ; and let the disadvan- 

 tages under which the Dutch naturalist laboured at the 

 time of his writing be fully taken into account. He 

 says that the Teredo varies greatly in dimensions, from 

 the minutest point to a foot or more in length, and that 

 specimens had been recorded which were even a foot 

 and a half and two feet long. The pallets (which he 

 styles " pinnae ") are likewise of unequal size in dif- 

 ferent individuals, the larger ones being more soft, and 

 of a chalky consistency and dull aspect, not unlike 

 morsels of old yellow cheese; they are frequently 

 mutilated or distorted. The Teredo, when taken out of 

 the wood, soon dies, although it be immediately placed 

 in clear sea-water. This observation does not agree 

 with those made by Professor Laurent in 1845 and 

 1847 with respect to T. Norvegica-, and M. Eydoux 

 ascertained that the last-named species, after having 

 been taken out of the wood and kept in sea-water, 

 actually secreted and formed a new calcareous sheath, 

 although very thin and more or less incomplete, into 

 which the animal retreated, closing the larger end with 

 an hemispherical epiphragm (like those made by indivi- 

 duals in wood), and constructing at the smaller end two 



