VIII. 

 PEARLS.— MOTHER-OF-PEARL. 



Fascbstatestg as was microscopic study, Tom 

 lost none of Ms admiration for tlie abalones, so 

 lustrous and iridescent, while Undine looked 

 for seed pearls in every bivalve that came into 

 her hands. 



Dr. McLean told them the pearly lining of 

 the abalones was called mother-of-pearl, or 

 nacre, while true pearls were the product of 

 different bivalves, the best "solidified drops 

 of dew," as the Orientals call them — ^being 

 found in the pearl oyster (^xivicula margari- 

 tifera). 



" According to an ancient fable," continued 

 the doctor, " oysters rose to iflie surface of the 

 water, opened their shells, and received the 

 drops of dew which were speedily transformed 

 to 'white pearls round e.' In recognition of 

 this fable Thomas Moore wrote : 



" Precious their tears as rain from the sky- 

 That turns into pearls as it falls in the sea. 

 61 



