166 NATURAL HISTORY of NORWAY. 



cannot perceive the Fifh \ for it hides itfelf, and part of the 

 fhell, in the fand. If they are taken haftily out of the water 

 the Fifh may be feen out of the fhell ; but when he finds him- 

 feif out of his element, he retires flowly into it again, and then 

 clofes it. They are taken up with the hands, or with a fort of 

 wooden pincers, and fometimes one may take them up by putting 

 a twig into the fhell while it is open ; upon which they imme- 

 diately clofe it, and hang fo fafl to the twig, that they may be 

 eafily drawn out of the water. If they do not hit upon the open- 

 ing at once, the fhell clofes as foon as it is touched ; and confe- 

 quently this method then proves ineffectual. They cannot lie upon 

 a hard or a rocky bottom, tho' they fometimes try to fix themfelves 

 in fuch places : but if they are thrown alive upon a fandy bottom, 

 they will fix themfelves in lefs than 24 hours. The thick end of 

 the fhell is fixed in the fand, and the other part appears above 

 the furface of it ; but when they are fmall they are quite covered 

 with the fand. They often move themfelves, but fo flow, that 

 their motion is imperceptible, and can only be' obferved by a little 

 track they leave behind them, like that of a fnail. It is a vulgar 

 error to imagine that they move themfelves to the furface of the 

 Water to breed pearls, by imbibing the dew ; and it is as ridi- 

 culous to think, that the pearls are the femen with which thefe 

 Mufcles propagate their fpecies : if that were the cafe, then the ' 

 greatefl number of pearls would be found where there are the 

 greatefl; number of Mufcles ; but experience fltiows the contrary. 

 Without doubt thefe Mufcles propagate their fpecies like other 

 Shell-fifh, tho 5 I have not been able to difcover the leafl diffe- 

 rence of fex between them. About Midfummer one may per- 

 ceive, within fbme of the fhells, a fort of clear femen, like the 

 white of an egg, which in a few weeks appears like fmall grains, 

 or eggs ; this feems to me to be their fpawn. Our fifhermen 

 generally find the pearl in that part of the Fifh which is called 

 the beard in the Oyfter, and fometimes on both fides ; but the 

 pearls are always flat on that fide that grows to the fhell. From 

 this we may conclude, that the fubflance of which pearls confifl;, 

 muit have been fluid at firft. As the pearls are frequently found 

 growing to the fhells, even thofe of the right water % as well as 

 thofe with a reddifh caffc ; and as thofe pearls that are fattened to 

 the shell are ufually of the fame colour with the shell, we may 

 conclude, that the pearl and shell are one fubftaiice. Some are 

 of opinion, that the Mufcle cannot produce the pearl of itfelf, 



* The word water is here a term of art, and fignifies the luftre of the ihelJ, as well 

 as the pearl. 



and 



