64 TESTACEA. 



But all the species are not used iiuliscrirainately, because some kin ds 

 are of unsuitable quality for consumption ; and all animals having an 

 election of the food they subsist on, others would prove of no utility in 

 the fisheries. 



Mytiltjs eduus. 



Many of the poorer classes dwelling in the vicinity of the sea, resort 

 to mussels, as forming a large portion of their subsistence, in default of 

 other and more costly food, and they find them sufficiently nutritious. 



Some among the multitude, without betraying any sensible diffe- 

 rence, are said to be deleterious, and individuals appear to have suffered 

 severely from them. Unfortunately this subject is still very obscure. 

 It is not explained what are noxious species, nor arc the precise places 

 whence they may be taken, clearly specified. Yet, I have heard some 

 places named wherein I am not assured that any excepting the edible 

 mussel would live. I have heard it alleged also, that metallic substances 

 were in the vicinity of some, whereon families had fed, and which proved 

 pernicious. No one has affirmed that the injury resulted from excess, as 

 is far from improbable. If these animals absorb a quantity of mud, this 

 iufi^redient itself is not to be thrown out of account. 



The ordinary test of boiling the mussels along with a silver coin is 

 easily adopted : if blackened, it indicates danger. 



The edible mussel is very profusely dispersed over parts of the coast 

 where there is an abundance of mud to be raised by the flowing tide, and 

 in places where the water is extremely narrow. This animal seems 

 always to dwell in very numerous societies, living half or nearly wholly 

 sunk in the soft bottom. Whether of the same species or not I am un- 

 certain, but it is found in multitudes only occasionally submerged by the 

 tide, on such as large stones on the shore, or on stone piers, covered at 

 high water, where many are so wedged together as to require some force 

 to be dislodged. Tliey very much resemble the edible mussel. I doubt 

 whether their place is ever shifted. Possibly it is their senSe of security 

 in the numerous cords affixing them, that originally induced choice 



