PAPERS READ BEFORE THE 
AMERICAN FISHERIES SOCIETY, 
WATE), THELR. DISCUSSIONS; 
SULIY Wire,  tooe. 
PART joeCon es: 
ON THE OCCURRENCE OF PEARLS IN) (aie 
UNITED STATES; AND)-SHALL: WB 
LEGISLATE “TO PRESERV= 
THE #ISHERTES: 
BY GEORGE FREDERIC KUNZ. 
Pearls are lustrous concretions, consisting essentially of 
carbonate of lime interlaminated with animal matter, 
found in the shells of certain mollusks. They are evident- 
ly a result of an abnormal secretory process caused by an 
irritation of the mantle of the mollusk consequent on the 
intrusion into the shell of some foreign body, as a grain 
of sand, an egg of the mollusk itself, or perhaps a cercar- 
ian parasite. It has also been suggested than an excess of 
carbonate of lime in the water may cause the development 
of the pearl. Accepting the former theory as the more 
probable one, it is easy to understand how a foreign body, 
which the mollusk is unable to expel, becomes encysted 
