220 MOLLUSCA. 



noxious fry of the star-fish ; and likewise to a disease tc 

 which the animal is subject in spring, under the influence 

 of which it melts away, and falls from the rocks. Besides 

 being useful to man as an article of subsistence, the mussel 

 supplies the fisherman with one ofhis most convenient and suc- 

 cessful baits. It is keenly taken both by cod and haddock. 

 To the cod-fish, however, the animal of the horse-mussel 

 (Modiola vulgaris} is more acceptable. 



The following unsuccessful attempt to plant a colony of 

 mussels is recorded by Mr. Stevenson in his interesting 

 work, (p. 73,) in which he gives the details of the erection 

 of the light-house on the Bell- Rock : " When the work- 

 men first landed upon the Bell-Rock, limpets of a very large 

 size were common, but were soon picked up for bait.' As 

 the limpets disappeared we endeavoured to plant a colony 

 of mussels, from beds at the mouth of the river Eden, of a 

 larger kind than those which seem to be natural to the 

 rock. These larger mussels were likely to have been use- 

 ful to the workmen, and might have been especially so to 

 the light-keepers, the future inhabitants of the rock, to 

 whom that delicate fish would have afforded a fresh meal, 

 as well as a better bait than the limpet ; but the mussels 

 were soon observed to open and die in great numbers. For 

 some time this was ascribed to the effects of the violent 

 surge of the sea, but the Buccinum lapillus, (Purpura,) 

 having greatly increased, it was ascertained that it had 

 proved a successful enemy to the mussel. The buccinum, 

 being furnished with a proboscis capable of boring, was ob- 

 served to perforate a small hole in the shell, and thus to 

 suck out the finer parts of the body of the mussel ; the 

 valves of course opened and the remainder of the fish was 

 washed away by the sea. The perforated hole is generally 



