142 TEREDINID.E. 



account of the voracity of N. fucata is confirmed by a 

 most valuable and instructive report presented to the 

 Academy of Sciences at Amsterdam, in I860, by Pro- 

 fessor Vrolik, the Secretary of a Commission which 

 was appointed to inquire into the natural history of the 

 Teredo and the best mode of preventing its ravages on 

 the coasts of Holland. It was there stated that the 

 larvae of the Nereilepas and Teredo live together ; and 

 it is probable that, instead of the annelid entering in 

 an adult state the canal of the shipworm, as Sellius con- 

 jectured, it deposits its eggs in the open siphons of the 

 latter, whence they afterwards find their way into the 

 body and are developed. The larvse of some dipterous 

 insects have been also observed by Dr. Verloren, as well 

 as Sellius, to prey on the Dutch shipworm. Cochleo- 

 ctonus vorax disposes in nearly a similar way of cer- 

 tain snails. I have seen shells of Helix strigella and 

 H. incarnata, each of which was occupied by a grub of 

 that beetle, coiled round in a spiral shape like the 

 snail which it had supplanted. The name of the artifi- 

 cial remedies which were known at the time when 

 Sellius wrote was legion. He reckoned about 600 

 kinds of ointment, or preparations of an oily nature; 

 and he proposed one, which we now call creosote, to 

 penetrate the pores of wood by some hydrostatic power, 

 and which would have the effect of hardening and pre- 

 serving the timber. He had no faith in the efficacy of 

 any poison, being fully impressed with the idea that the 

 Teredo feeds on wood only; nor did he believe that, 

 even if this were not the case, the wood could be sa- 

 turated or imbued with poison by the most expensive 

 process that it was possible to discover. A thick and 

 durable coat of varnish, applied to the surface of the 

 wood, was in his judgment the best preventive, because 



