surrounded by nacre-producing cells. Year 

 after year and layer after layer this nucleus 

 is covered with the pearly matter as the 

 animal grows, the fleshy pouch expanding 

 to accommodate the increasing size of the 

 pearl. As the mantle is constantly in 

 motion, the pearl is slowly turned or revolved 

 in its fold thus distributing the layers of 

 nacre evenly upon its surface until with 

 time, if the conditions are favorable, it 

 becomes a thing of beauty, giving pleasure to 

 all who behold it. Pearls are sometimes 

 lost by the breaking of the walls of the 

 enclosing pocket in which they grow and 

 have been found in the beds of streams. 

 Sometimes too, a mussel outlives its youth 

 and vigorous maturity, all the while increas- 

 ing the size of a pearl within its mantle; but 

 with old age comes decay and the pearl 

 becomes dead and lifeless. Then, as often 

 happens, a pearl is found which at first 

 appears worthless but whose outer coats 

 enclose a bright and lively gem. In such a 

 case the outer layers may be removed by 

 careful manipulation and the pearl restored 

 to its original perfection and beauty. Pearls 

 of this class are called "peelers." 



Pearl Oyster 



Meleagrina Margaritifera 



