1 66 PEARLS AND PEARLING 



The pearl fisheries of our rivers are very extensive, yet 

 it would be very difficult to find two colored pearls which 

 are alike in every particular. 



The pearls from the Ceylon fishery are nearly alike in 

 color, and there lore jewelers depend upon them when 

 they wish to make a large necklace. This is a valuable 

 advantage which our colored pearls do not have ; yet 

 scientific management may help to overcome this diffi- 

 culty by supplying a system whereby pearls of any color 

 may be artificially cultivated. These colors are not a 

 mere matter of chance. There is a real cause for every 

 effect, and while we may not know the reason why some 

 pearls are white, while others are green and pink, there 

 is a good reason for it. 



Shells which are white in one river are pink in an- 

 other stream ; while some which are pink or purple in the 

 headwaters of a river may be white a hundred miles 

 down the stream. All must agree that there are some 

 local conditions which influence the color of the shells 

 and pearls. 



In the summer of 1910 the author gathered shells in 

 the Mississippi River, near Port Byron, Illinois, where 

 he sold his shells to Mr. J. F. Normand. 



While working there he noticed that the nigger-heads 

 and several other mussels with shells having white nacre 

 were at rest, while the lady fingers and several others 

 having pink nacre were always feeding. At that time the 

 Mississippi River was lower than it had been for many 

 years. The Northern States and Canada were suffering 

 from a very prolonged drought. All the creeks and 



