574 
MUSCLE. 
the formation of pearls in the river pearl muscle 
{Mya margaritifera) which, though a different shell, 
and belonging to another genus, may be mentioned 
in this place on account of this singular circum- 
stance. It appears that Linnaeus (by some means, of 
which we are totally unacquainted,) contrived to 
put these muscles into a state of producing pearls at 
his pleasure, though the final effect did not take 
place for several years. It was supposed, from a 
paper which was published many years after the 
discovery by Chemnitz, that the method consisted 
in injuring the shell externally, perhaps by a perfo- 
ration ; for it has been observed that these concre- 
tions, in the fresh water muscle, are found in the 
inside exactly opposite to the perforations and in- 
juries made by serpulce and other animals. How- 
ever this may be, the states of Sweden thought the 
subject of sufficient importance to reward Linnaeus 
with a premium of 1 800 dollars, which is equal to 
about 450 pounds sterling. This curious discovery 
is more particularly noticed in the General View of 
the Writings of Linnaeus, edited by the learned 
Dr. Maton ; where the reader will find the transla- 
tion of a very interesting memorial, which was laid 
before the states for the purpose of enforcing Lin- 
naeus’s claims on this occasion. 
It has been long known that this species of fresh 
water muscle occasionally produces pearls, and 
mention is made in Lowthorp’s Abridgement of the 
Philosophical Transactions, of several of large size 
found in the rivers of the county of Tyrone and 
