124 PEARLS [CH. 



pearl that came from Singapore. He was very scep- 

 tical, however, because it resembled rather closely a 

 pearl from the bivalve Tridacna and its composition 

 was very different from the constituents of the cocoa- 

 nut. Calcium is usually deposited in plants as oxalate, 

 although of course numerous calcareous algae are 

 known in which calcium carbonate is deposited. 



CHAPTER X 



THE PEARL OYSTER — THE TRADER — THE MAN^ OF 

 SCIENCE — THE CULTIVATION OF PEARL OYSTERS 



We have described the pearl, the pearl fishery, 

 and the economic and scientific aspects of pearling ; 

 what should be more natural than a combination of 

 science with the pearl industry? Science is now 

 such a force in the world that we should expect 

 it to come to the aid of the pearl fisher. 



Before the jeweller can mount the valuable gems 

 from molluscs of the sea or fresh water, the fisher 

 must supply him with the materials for his trade. 

 This means first and foremost that large beds of 

 flourishing pearl-producing shellfish are required. 

 Then, secondly, we require that these molluscs shall 



