1892-93-] The Shipworm. 71 



encroachments of the sea. Great consternation must have 

 prevailed on several occasions when it became known that 

 the dykes were giving way, through the destruction by the 

 Teredo of the supporting piles. The species with such an evil 

 reputation is referred by some Dutch naturalists to the Teredo 

 Sellii — named after the Dutchman Godfrey Sellius, who wrote 

 a treatise on the animal — a small quarto of 360 pages. Piles 

 driven only six or seven weeks previously were seen to be 

 entirely eaten through and robbed of all their strength. In 

 this way the island of Walcheren was in 1733 threatened 

 with destruction. From time to time the same danger was 

 discovered in other places, especially on the Zuider Zee, and 

 West Friesland was in consequence forced to mask its dykes 

 with large stones, which occasioned great expense, as they had 

 to be brought from abroad. Many remedies were tried, with 

 little if any success. The Teredo itself, however, abandoned the 

 work, and a feeling of greater security immediately resulted. 



An interesting instance of the utility of the Teredo in 

 assisting to inflict punishment on an enemy, but one which 

 in these days of iron ships and ironclads will not likely be 

 repeated, is given by Eear-Admiral Colomb in his valuable 

 work on 'Naval Warfare.' He says that in 1588 the 

 English Admirals, Hawkins and Frobisher, paralysed to an 

 irrecoverable extent the whole West Indian trade of Spain by 

 simply lying across the Spanish " trade-route," and prevent- 

 ing for a whole year the sailing of the Spanish ships from 

 the West Indies. The imprisonment of the ships was a heavy 

 enough blow. " But in this case," he continues, " it was still 

 worse for Spain, as in the then unsheathed state of ships' 

 bottoms, lying in tropical waters for a summer produced weak- 

 ness of structure almost amounting to disablement, from the 

 ravages of the Teredo. As a consequence, about a hundred of 

 these detained ships were lost with their rich cargoes on the 

 return voyage to Spain next year." During the Crimean war 

 British gunboats suffered in a like manner as much from dry- 

 rot and Teredos as they did from the shot and shell of the 

 Russians. 



In the 'Scientific American' of 25th April 1891 it is 

 stated that in the year 1884 one of the large saw-mill com- 

 panies of Puget Sound lost 50,000,000 feet of logs, equal to 



