MYTILIDiE. PEARLS. 
53 
prevailing, which caused much distress, and that, in the 
month of June or July, twenty poor families from the 
interior of the country encamped on the roadside, near 
the beach to the west of Holy wood, remaining there about 
five weeks, subsisting partly on such vegetable matter 
as they could pick up about the hedgerows and fences, 
but principally upon the mussels which are so abundant 
on the extensive mud- banks of the neighbouring coast. 
No instance of disease from this diet occurred, and during 
that summer the poorer classes in the village appeared 
quite as healthy as in other years, though mussels formed 
their chief food. 
Athenaius says that mussels are moderately nutritious, 
and digestible ; the best being the Ephesian kind, which 
are particularly good when taken about the end of au- 
tumn (vol. i. p. 150). 
In the Eeroe Isles, the large horse-mussel, Mytilus 
modiolus, is eaten, and they call it in Eeroese ova. Mr. 
Alder tells us that at Rothesay they are collected for 
food* (though not so delicate as Mytilus edulis), and in 
the Shetland Isles for bait, where they are known by 
the name of yoags. They are also eaten in the north 
of Ireland, but not considered very good, on account of 
their strong scent and flavour ; but they are capital 
bait for cod. At Tenby they call Mytilus modiolus the 
poisonous mussel, and affirm that no one ever ventures 
to eat it. 
Pearls are occasionally found in the common mussel, 
and also in the oyster, scallop, cockle, periwinkle, 
and pinna; but they are generally inferior in size and 
quality to those of the freshwater pearl-mussel, Unio 
margaritiferus ; and Mr. Beckman, in his ^ History of 
* Forbes and Hanley, Brit. Mollusca, vol. ii. p. 185. 
